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Reset Value (hex) Reg. Descr. 7 6 5 4 3 2 10 with Link 80 RESERVED 81 SP SP[7:0] 07 Stack Pointer (SP), page 21 82 DPL DPL[7:0] 00 Data Pointer (DPTR), p age 21 83 DPH DPH[7:0] 00 84 RESERVED 85 DPTC – AT – – – DPSEL[2:0] 00 Table 13., page 37 86 DPTM – – – – MD1[1:0] MD0[1:0] 00 Table 14., page 38 87 PCON SMOD0 SMOD1 – POR RCLK1 TCLK1 PD IDLE 00 Table 24., page 50 88(1) TCON TF1 <8Fh> TR1 <8Eh> TF0 <8Dh> TR0 <8Ch> IE1 <8Bh> IT1 <8Ah> IE0 <89h> IT0 <88h> 00 Table 39., page 70 89 TMOD GATE C/T M1 M0 GATE C/T M1 M0 00 Table 40., page 72 8A TL0 TL0[7:0] 00 Standard Timer SFRs, pag e 69 8B TL1 TL1[7:0] 00 8C TH0 TH0[7:0] 00 8D TH1 TH1[7:0] 00 8E P1SFS0 P1SFS0[7:0] 00 Table 29., page 60 8F P1SFS1 P1SFS1[7:0] 00 Table 30., page 60 90(1) P1 P1.7 <97h> P1.6 <96h> P1.5 <95h> P1.4 <94h> P1.3 <93h> P1.2 <92h> P1.1 <91h> P1.0 <90h> FF Table 25., page 57 91 P3SFS P3SFS[7:0] 00 Table 28., page 60 92 P4SFS0 P4SFS0[7:0] 00 Table 32., page 61 93 P4SFS1 P4SFS1[7:0] 00 Table 33., page 6125/231 uPSD33xx 94 ADCPS – – – – ADCCE ADCPS[2:0] 00 Table 64., page 122 95 ADAT0 ADATA[7:0] 00 Table 65., page 122 96 ADAT1 – – – – – – ADATA[9:8] 00 Table 66., page 122 97 ACON AINTF AINTEN ADEN ADS[2:0] ADST ADSF 00 Table 63., page 121 98(1) SCON0 SM0 <9Fh> SM1 <9Eh> SM2 <9Dh> REN <9Ch> TB8 <9Bh> RB8 <9Ah> TI <99h> RI <9h8> 00 Table 45., page 82 99 SBUF0 SBUF0[7:0] 00 Figure 25., page 79 9A RESERVED 9B RESERVED 9C RESERVED 9D BUSCON EPFQ EBC WRW1 WRW0 RDW1 RDW0 CW1 CW0 EB Table 35., page 63 9E RESERVED 9F RESERVED A0 RESERVED A1 RESERVED A2 PCACL0 PCACL0[7:0] 00 Table 67., page 124 A3 PCACH0 PCACH0[7:0] 00 Table 67., page 124 A4 PCACON0 EN_ALL EN_PCA EOVF1 PCA_IDL – – CLK_SEL[1:0] 00 Table 70., page 129 A5 PCASTA OVF1 INTF5 INTF4 INTF3 OVF0 INTF2 INTF1 INTF0 00 Table 72., page 131 A6 WDTRST WDTRST[7:0] 00 Table 38., page 68 A7 IEA EADC ESPI EPCA ES1 – – EI2C – 00 Table 18., page 44 SFR Addr (hex) SFR Name Bit Name and Reset Value (hex) Reg. Descr. 7 6 5 4 3 2 10 with LinkuPSD33xx 26/231 A8(1) IE EA – ET2 ES0 ET1 EX1 ET0 EX0 00 Table 17., page 43 A9 TCMMODE 0 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] 00 Table 73., page 132 AA TCMMODE 1 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] 00 AB TCMMODE 2 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] 00 AC CAPCOML 0 CAPCOML0[7:0] 00 Table 67., page 124 AD CAPCOMH 0 CAPCOMH0[7:0] 00 AE WDTKEY WDTKEY[7:0] 55 Table 37., page 68 AF CAPCOML 1 CAPCOML1[7:0] 00 Table 67., page 124 B0(1) P3 P3.7 P3.6 P3.5 P3.4 P3.3 P3.2 P3.1 P3.0 FF Table 26., page 58 B1 CAPCOMH 1 CAPCOMH1[7:0] 00 Table 67., page 124 B2 CAPCOML 2 CAPCOML2[7:0] 00 B3 CAPCOMH 2 CAPCOMH2[7:0] 00 B4 PWMF0 PWMF0[7:0] 00 B5 RESERVED B6 RESERVED B7 IPA PADC PSPI PPCA PS1 – – PI2C – 00 Table 20., page 45 B8(1) IP – – PT2 PS0 PT1 PX1 PT0 PX0 00 Table 19., page 44 B9 RESERVED BA PCACL1 PCACL1[7:0] 00 Table 67., page BB PCACH1 PCACH1[7:0] 00 124 BC Table 2671 page 12027/231 uPSD33xx BD TCMMODE 3 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] 00 Table 73., page 132 BE TCMMODE 4 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] 00 BF TCMMODE 5 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] 00 C0(1) P4 P4.7 P4.6 P4.5 P4.4 P4.3 P4.2 P4.1 P4.0 FF Table 27., page 58 C1 CAPCOML 3 CAPCOML3[7:0] 00 Table 67., page 124 C2 CAPCOMH 3 CAPCOMH3[7:0] 00 C3 CAPCOML 4 CAPCOML4[7:0] 00 C4 CAPCOMH 4 CAPCOMH4[7:0] 00 C5 CAPCOML 5 CAPCOML5[7:0] 00 C6 CAPCOMH 5 CAPCOMH5[7:0] 00 C7 PWMF1 PWMF1[7:0] 00 C8(1) T2CON TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2 CP/ RL2 00 Table 41., page 75 C9 RESERVED CA RCAP2L RCAP2L[7:0] 00 Standard Timer SFRs, pag e 69 CB RCAP2H RCAP2H[7:0] 00 CC TL2 TL2[7:0] 00 CD TH2 TH2[7:0] 00 CE IRDACON – IRDA_EN BIT_PULS CDIV4 CDIV3 CDIV2 CDIV1 CDIV0 0F Table 48., page 93 D0(1) PSW CY AC F0 RS[1:0] OV – P 00 Program Status Word (PSW), pa ge 22 D1 RESERVED D2 SPICLKD SPICLKD[5:0] – – 04 Table 61., page 118 D3 SPISTAT – – – BUSY TEISF RORISF TISF RISF 02 Table 62., page 119 SFR Addr (hex) SFR Name Bit Name and Reset Value (hex) Reg. Descr. 7 6 5 4 3 2 10 with LinkuPSD33xx 28/231 D4 SPITDR SPITDR[7:0] 00 Table 62., page D5 SPIRDR SPIRDR[7:0] 00 119 D6 SPICON0 – TE RE SPIEN SSEL FLSB SPO – 00 Table 59., page 117 D7 SPICON1 – – – – TEIE RORIE TIE RIE 00 Table 60., page 118 D8(1) SCON1 SM0 SM2

REN TB8 RB8 TI RI 00 Table 46., page 83 D9 SBUF1 SBUF1[7:0] 00 Figure 25., page 79 DA RESERVED DB S1SETUP SS_EN SMPL_SET[6:0] 00 Table 55., page 105 DC S1CON CR2 EN1 STA STO ADDR AA CR1 CR0 00 Table 50., page 100 DD S1STA GC STOP INTR TX_MD B_BUSY B_LOST ACK_R SLV 00 Table 52., page 103 DE S1DAT S1DAT[7:0] 00 Table 53., page 104 DF S1ADR S1ADR[7:0] 00 Table 54., page 104 E0(1) A A[7:0] 00 Accumulat or (ACC), pa ge 21 E1 to EF RESERVED F0(1) B B[7:0] 00 B Register (B), page 21 F1 RESERVED F2 RESERVED F3 RESERVED F4 RESERVED F5 RESERVED F6 RESERVED SFR Addr (hex) SFR Name Bit Name and Reset Value (hex) Reg. Descr. 7 6 5 4 3 2 10 with Link29/231 uPSD33xx Note: 1. This SFR can be addressed by individual bits (Bit Address mode) or addressed by the entire byte (Direct Address mode). F7 RESERVED F8 RESERVED F9 CCON0 – – – DBGCE CPU_AR CPUPS[2:0] 10 Table 21., page 47 FA RESERVED FB CCON2 – – – PCA0CE PCA0PS[3:0] 10 Table 68., page 125 FC CCON3 – – – PCA1CE PCA1PS[3:0] 10 Table 69., page 125 FD RESERVED FE RESERVED FF RESERVED SFR Addr (hex) SFR Name Bit Name and Reset Value (hex) Reg. Descr. 7 6 5 4 3 2 10 with LinkuPSD33xx 30/231 8032 ADDRESSING MODES The 8032 MCU uses 11 different addressing modes listed below: ■ Register ■ Direct ■ Register Indirect ■ Immediate ■ External Direct ■ External Indirect ■ Indexed ■ Relative ■ Absolute ■ Long ■ Bit Register Addressing This mode uses the contents of one of the registers R0 - R7 (selected by the last three bits in the instruction opcode) as the operand source or destination. This mode is very efficient since an additional instruction byte is not needed to identify the operand. For example: Direct Addressing This mode uses an 8-bit address, which is contained in the second byte of the instruction, to directly address an operand which resides in either 8032 DATA SRAM (internal address range 00h- 07Fh) or resides in 8032 SFR (internal address range 80h-FFh). This mode is quite fast since the range limit is 256 bytes of internal 8032 SRAM. For example: Register Indirect Addressing This mode uses an 8-bit address contained in either Register R0 or R1 to indirectly address an operand which resides in 8032 IDATA SRAM (internal address range 80h-FFh). Although 8032 SFR registers also occupy the same physical address range as IDATA, SFRs will not be accessed by Register Indirect mode. SFRs may only be accesses using Direct address mode. For example: Immediate Addressing This mode uses 8-bits of data (a constant) contained in the second byte of the instruction, and stores it into the memory location or register indicated by the first byte of the instruction. Thus, the data is immediately available within the instruction. This mode is commonly used to initialize registers and SFRs or to perform mask operations. There is also a 16-bit version of this mode for loading the DPTR Register. In this case, the two bytes following the instruction byte contain the 16-bit value. For example: External Direct Addressing This mode will access external memory (XDATA) by using the 16-bit address stored in the DPTR Register. There are only two instructions using this mode and both use the accumulator to either receive a byte from external memory addressed by DPTR or to send a byte from the accumulator to the address in DPTR. The uPSD33xx has a special feature to alternate the contents (source and destination) of DPTR rapidly to implement very efficient memory-to-memory transfers. For example: Note: See details in DUAL DATA POINTERS, page 37. External Indirect Addressing This mode will access external memory (XDATA) by using the 8-bit address stored in either Register R0 or R1. This is the fastest way to access XDATA (least bus cycles), but because only 8-bits are available for address, this mode limits XDATA to a size of only 256 bytes (the traditional Port 2 of the 8032 MCU is not available in the uPSD33xx, so it is not possible to write the upper address byte). This mode is not supported by uPSD33xx. For example: MOV A, R7 ; Move contents of R7 to accumulator MOV A, 40h ; Move contents of DATA SRAM ; at location 40h into the accumulator MOV A, @R0 ; Move into the accumulator the ; contents of IDATA SRAM that is ; pointed to by the address ; contained in R0. MOV A, 40# ; Move the constant, 40h, into ; the accumulator MOV DPTR, 1234# ; Move the constant, 1234h, into ; DPTR MOVX A, @DPTR ; Move contents of accumulator to ; XDATA at address contained in ; DPTR MOVX @DPTR, A ; Move XDATA to accumulator MOVX @R0,A ; Move into the accumulator the ; XDATA that is pointed to by ; the address contained in R0.31/231 uPSD33xx Indexed Addressing This mode is used for the MOVC instruction which allows the 8032 to read a constant from program memory (not data memory). MOVC is often used to read look-up tables that are embedded in program memory. The final address produced by this mode is the result of adding either the 16-bit PC or DPTR value to the contents of the accumulator. The value in the accumulator is referred to as an index. The data fetched from the final location in program memory is stored into the accumulator, overwriting the index value that was previously stored there. For example: Relative Addressing This mode will add the two’s-compliment number stored in the second byte of the instruction to the program counter for short jumps within +128 or – 127 addresses relative to the program counter. This is commonly used for looping and is very efficient since no additional bus cycle is needed to fetch the jump destination address. For example: Absolute Addressing This mode will append the 5 high-order bits of the address of the next instruction to the 11 low-order bits of an ACALL or AJUMP instruction to produce a 16-bit jump address. The jump will be within the same 2K byte page of program memory as the first byte of the following instruction. For example: Long Addressing This mode will use the 16-bits contained in the two bytes following the instruction byte as a jump destination address for LCALL and LJMP instructions. For example: Bit Addressing This mode allows setting or clearing an individual bit without disturbing the other bits within an 8-bit value of internal SRAM. Bit Addressing is only available for certain locations in 8032 DATA and SFR memory. Valid locations are DATA addresses 20h - 2Fh and for SFR addresses whose base address ends with 0h or 8h. (Example: The SFR, IE, has a base address of A8h, so each of the eight bits in IE can be addressed individually at address A8h, A9h, ...up to AFh.) For example: MOVC A, @A+DPTR; Move code byte relative to ; DPTR into accumulator MOVC A, @A+PC ; Move code byte relative to PC ; into accumulator SJMP 34h ; Jump 34h bytes ahead (in program ; memory) of the address at which ; the SJMP instruction is stored. If ; SJMP is at 1000h, program ; execution jumps to 1034h. AJMP 0500h ; If next instruction is located at ; address 4000h, the resulting jump ; will be made to 4500h. LJMP 0500h ; Unconditionally jump to address ; 0500h in program memory SETB AFh ; Set the individual EA bit (Enable All ; Interrupts) inside the SFR Register, ; IE. uPSD33xx 32/231 uPSD33xx INSTRUCTION SET SUMMARY Tables 6 through 11 list all of the instructions supported by the uPSD33xx, including the number of bytes and number of machine cycles required to implement each instruction. This is the standard 8051 instruction set. The meaning of “machine cycles” is how many 8032 MCU core machine cycles are required to execute the instruction. The “native” duration of all machine cycles is set by the memory wait state settings in the SFR, BUSCON, and the MCU clock divider selections in the SFR, CCON0 (i.e. a machine cycle is typically set to 4 MCU clocks for a 5V uPSD33xx). However, an individual machine cycle may grow in duration when either of two things happen: 1. a stall is imposed while loading the 8032 PreFetch Queue (PFQ); or 2. the occurrence of a cache miss in the Branch Cache (BC) during a branch in program execution flow. See 8032 MCU CORE PERFORMANCE ENHANCEMENTS, page 17 or more details. But generally speaking, during typical program execution, the PFQ is not empty and the BC has no misses, producing very good performance without extending the duration of any machine cycles. The uPSD33xx Programmers Guide describes each instruction operation in detail. Table 6. Arithmetic Instruction Set Note: 1. All mnemonics copyrighted ©Intel Corporation 1980. Mnemonic(1) and Use Description Length/Cycles ADD A, Rn Add register to ACC 1 byte/1 cycle ADD A, Direct Add direct byte to ACC 2 byte/1 cycle ADD A, @Ri Add indirect SRAM to ACC 1 byte/1 cycle ADD A, #data Add immediate data to ACC 2 byte/1 cycle ADDC A, Rn Add register to ACC with carry 1 byte/1 cycle ADDC A, direct Add direct byte to ACC with carry 2 byte/1 cycle ADDC A, @Ri Add indirect SRAM to ACC with carry 1 byte/1 cycle ADDC A, #data Add immediate data to ACC with carry 2 byte/1 cycle SUBB A, Rn Subtract register from ACC with borrow 1 byte/1 cycle SUBB A, direct Subtract direct byte from ACC with borrow 2 byte/1 cycle SUBB A, @Ri Subtract indirect SRAM from ACC with borrow 1 byte/1 cycle SUBB A, #data Subtract immediate data from ACC with borrow 2 byte/1 cycle INC A Increment A 1 byte/1 cycle INC Rn Increment register 1 byte/1 cycle INC direct Increment direct byte 2 byte/1 cycle INC @Ri Increment indirect SRAM 1 byte/1 cycle DEC A Decrement ACC 1 byte/1 cycle DEC Rn Decrement register 1 byte/1 cycle DEC direct Decrement direct byte 2 byte/1 cycle DEC @Ri Decrement indirect SRAM 1 byte/1 cycle INC DPTR Increment Data Pointer 1 byte/2 cycle MUL AB Multiply ACC and B 1 byte/4 cycle DIV AB Divide ACC by B 1 byte/4 cycle DA A Decimal adjust ACC 1 byte/1 cycle33/231 uPSD33xx Table 7. Logical Instruction Set Note: 1. All mnemonics copyrighted ©Intel Corporation 1980. Mnemonic(1) and Use Description Length/Cycles ANL A, Rn AND register to ACC 1 byte/1 cycle ANL A, direct AND direct byte to ACC 2 byte/1 cycle ANL A, @Ri AND indirect SRAM to ACC 1 byte/1 cycle ANL A, #data AND immediate data to ACC 2 byte/1 cycle ANL direct, A AND ACC to direct byte 2 byte/1 cycle ANL direct, #data AND immediate data to direct byte 3 byte/2 cycle ORL A, Rn OR register to ACC 1 byte/1 cycle ORL A, direct OR direct byte to ACC 2 byte/1 cycle ORL A, @Ri OR indirect SRAM to ACC 1 byte/1 cycle ORL A, #data OR immediate data to ACC 2 byte/1 cycle ORL direct, A OR ACC to direct byte 2 byte/1 cycle ORL direct, #data OR immediate data to direct byte 3 byte/2 cycle SWAP A Swap nibbles within the ACC 1 byte/1 cycle XRL A, Rn Exclusive-OR register to ACC 1 byte/1 cycle XRL A, direct Exclusive-OR direct byte to ACC 2 byte/1 cycle XRL A, @Ri Exclusive-OR indirect SRAM to ACC 1 byte/1 cycle XRL A, #data Exclusive-OR immediate data to ACC 2 byte/1 cycle XRL direct, A Exclusive-OR ACC to direct byte 2 byte/1 cycle XRL direct, #data Exclusive-OR immediate data to direct byte 3 byte/2 cycle CLR A Clear ACC 1 byte/1 cycle CPL A Compliment ACC 1 byte/1 cycle RL A Rotate ACC left 1 byte/1 cycle RLC A Rotate ACC left through the carry 1 byte/1 cycle RR A Rotate ACC right 1 byte/1 cycle RRC A Rotate ACC right through the carry 1 byte/1 cycleuPSD33xx 34/231 Table 8. Data Transfer Instruction Set Note: 1. All mnemonics copyrighted ©Intel Corporation 1980. Mnemonic(1) and Use Description Length/Cycles MOV A, Rn Move register to ACC 1 byte/1 cycle MOV A, direct Move direct byte to ACC 2 byte/1 cycle MOV A, @Ri Move indirect SRAM to ACC 1 byte/1 cycle MOV A, #data Move immediate data to ACC 2 byte/1 cycle MOV Rn, A Move ACC to register 1 byte/1 cycle MOV Rn, direct Move direct byte to register 2 byte/2 cycle MOV Rn, #data Move immediate data to register 2 byte/1 cycle MOV direct, A Move ACC to direct byte 2 byte/1 cycle MOV direct, Rn Move register to direct byte 2 byte/2 cycle MOV direct, direct Move direct byte to direct 3 byte/2 cycle MOV direct, @Ri Move indirect SRAM to direct byte 2 byte/2 cycle MOV direct, #data Move immediate data to direct byte 3 byte/2 cycle MOV @Ri, A Move ACC to indirect SRAM 1 byte/1 cycle MOV @Ri, direct Move direct byte to indirect SRAM 2 byte/2 cycle MOV @Ri, #data Move immediate data to indirect SRAM 2 byte/1 cycle MOV DPTR, #data16 Load Data Pointer with 16-bit constant 3 byte/2 cycle MOVC A, @A+DPTR Move code byte relative to DPTR to ACC 1 byte/2 cycle MOVC A, @A+PC Move code byte relative to PC to ACC 1 byte/2 cycle MOVX A, @Ri Move XDATA (8-bit addr) to ACC 1 byte/2 cycle MOVX A, @DPTR Move XDATA (16-bit addr) to ACC 1 byte/2 cycle MOVX @Ri, A Move ACC to XDATA (8-bit addr) 1 byte/2 cycle MOVX @DPTR, A Move ACC to XDATA (16-bit addr) 1 byte/2 cycle PUSH direct Push direct byte onto stack 2 byte/2 cycle POP direct Pop direct byte from stack 2 byte/2 cycle XCH A, Rn Exchange register with ACC 1 byte/1 cycle XCH A, direct Exchange direct byte with ACC 2 byte/1 cycle XCH A, @Ri Exchange indirect SRAM with ACC 1 byte/1 cycle XCHD A, @Ri Exchange low-order digit indirect SRAM with ACC 1 byte/1 cycle35/231 uPSD33xx Table 9. Boolean Variable Manipulation Instruction Set Note: 1. All mnemonics copyrighted ©Intel Corporation 1980. Mnemonic(1) and Use Description Length/Cycles CLR C Clear carry 1 byte/1 cycle CLR bit Clear direct bit 2 byte/1 cycle SETB C Set carry 1 byte/1 cycle SETB bit Set direct bit 2 byte/1 cycle CPL C Compliment carry 1 byte/1 cycle CPL bit Compliment direct bit 2 byte/1 cycle ANL C, bit AND direct bit to carry 2 byte/2 cycle ANL C, /bit AND compliment of direct bit to carry 2 byte/2 cycle ORL C, bit OR direct bit to carry 2 byte/2 cycle ORL C, /bit OR compliment of direct bit to carry 2 byte/2 cycle MOV C, bit Move direct bit to carry 2 byte/1 cycle MOV bit, C Move carry to direct bit 2 byte/2 cycle JC rel Jump if carry is set 2 byte/2 cycle JNC rel Jump if carry is not set 2 byte/2 cycle JB rel Jump if direct bit is set 3 byte/2 cycle JNB rel Jump if direct bit is not set 3 byte/2 cycle JBC bit, rel Jump if direct bit is set and clear bit 3 byte/2 cycleuPSD33xx 36/231 Table 10. Program Branching Instruction Set Note: 1. All mnemonics copyrighted ©Intel Corporation 1980. Table 11. Miscellaneous Instruction Set Note: 1. All mnemonics copyrighted ©Intel Corporation 1980. Table 12. Notes on Instruction Set and Addressing Modes Mnemonic(1) and Use Description Length/Cycles ACALL addr11 Absolute subroutine call 2 byte/2 cycle LCALL addr16 Long subroutine call 3 byte/2 cycle RET Return from subroutine 1 byte/2 cycle RETI Return from interrupt 1 byte/2 cycle AJMP addr11 Absolute jump 2 byte/2 cycle LJMP addr16 Long jump 3 byte/2 cycle SJMP rel Short jump (relative addr) 2 byte/2 cycle JMP @A+DPTR Jump indirect relative to the DPTR 1 byte/2 cycle JZ rel Jump if ACC is zero 2 byte/2 cycle JNZ rel Jump if ACC is not zero 2 byte/2 cycle CJNE A, direct, rel Compare direct byte to ACC, jump if not equal 3 byte/2 cycle CJNE A, #data, rel Compare immediate to ACC, jump if not equal 3 byte/2 cycle CJNE Rn, #data, rel Compare immediate to register, jump if not equal 3 byte/2 cycle CJNE @Ri, #data, rel Compare immediate to indirect, jump if not equal 3 byte/2 cycle DJNZ Rn, rel Decrement register and jump if not zero 2 byte/2 cycle DJNZ direct, rel Decrement direct byte and jump if not zero 3 byte/2 cycle Mnemonic(1) and Use Description Length/Cycles NOP No Operation 1 byte/1 cycle Rn Register R0 - R7 of the currently selected register bank. direct 8-bit address for internal 8032 DATA SRAM (locations 00h - 7Fh) or SFR registers (locations 80h - FFh). @Ri 8-bit internal 8032 SRAM (locations 00h - FFh) addressed indirectly through contents of R0 or R1. #data 8-bit constant included within the instruction. #data16 16-bit constant included within the instruction. addr16 16-bit destination address used by LCALL and LJMP. addr11 11-bit destination address used by ACALL and AJMP. rel Signed (two-s compliment) 8-bit offset byte. bit Direct addressed bit in internal 8032 DATA SRAM (locations 20h to 2Fh) or in SFR registers (88h, 90h, 98h, A8h, B0, B8h, C0h, C8h, D0h, D8h, E0h, F0h).37/231 uPSD33xx DUAL DATA POINTERS XDATA is accessed by the External Direct addressing mode, which uses a 16-bit address stored in the DPTR Register. Traditional 8032 architecture has only one DPTR Register. This is a burden when transferring data between two XDATA locations because it requires heavy use of the working registers to manipulate the source and destination pointers. However, the uPSD33xx has two data pointers, one for storing a source address and the other for storing a destination address. These pointers can be configured to automatically increment or decrement after each data transfer, further reducing the burden on the 8032 and making this kind of data movement very efficient. Data Pointer Control Register, DPTC (85h) By default, the DPTR Register of the uPSD33xx will behave no different than in a standard 8032 MCU. The DPSEL0 Bit of SFR register DPTC shown in Table 13, selects which one of the two “background” data pointer registers (DPTR0 or DPTR1) will function as the traditional DPTR Register at any given time. After reset, the DPSEL0 Bit is cleared, enabling DPTR0 to function as the DPTR, and firmware may access DPTR0 by reading or writing the traditional DPTR Register at SFR addresses 82h and 83h. When the DPSEL0 bit is set, then the DPTR1 Register functions as DPTR, and firmware may now access DPTR1 through SFR registers at 82h and 83h. The pointer which is not selected by the DPSEL0 bit remains in the background and is not accessible by the 8032. If the DPSEL0 bit is never set, then the uPSD33xx will behave like a traditional 8032 having only one DPTR Register. To further speed XDATA to XDATA transfers, the SFR bit, AT, may be set to automatically toggle the two data pointers, DPTR0 and DPTR1, each time the standard DPTR Register is accessed by a MOVX instruction. This eliminates the need for firmware to manually manipulate the DPSEL0 bit between each data transfer. Detailed description for the SFR register DPTC is shown in Table 13. Table 13. DPTC: Data Pointer Control Register (SFR 85h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – AT – – – – – DPSEL0 Details Bit Symbol R/W Definition 7 – – Reserved 6 AT R,W 0 = Manually Select Data Pointer 1 = Auto Toggle between DPTR0 and DPTR1 5-1 – – Reserved 0 DPSE0 R,W 0 = DPTR0 Selected for use as DPTR 1 = DPTR1 Selected for use as DPTRuPSD33xx 38/231 Data Pointer Mode Register, DPTM (86h) The two “background” data pointers, DPTR0 and DPTR1, can be configured to automatically increment, decrement, or stay the same after a MOVX instruction accesses the DPTR Register. Only the currently selected pointer will be affected by the increment or decrement. This feature is controlled by the DPTM Register defined in Table 14. The automatic increment or decrement function is effective only for the MOVX instruction, and not MOVC or any other instruction that uses the DTPR Register. Firmware Example. The 8051 assembly code illustrated in Table 15 shows how to transfer a block of data bytes from one XDATA address region to another XDATA address region. Auto-address incrementing and auto-pointer toggling will be used. Table 14. DPTM: Data Pointer Mode Register (SFR 86h, reset value 00h) Table 15. 8051 Assembly Code Example Note: 1. The code loop where the data transfer takes place is only 3 lines of code. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – – – MD11 MD10 MD01 MD00 Details Bit Symbol R/W Definition 7-4 – – Reserved 3-2 MD[11:10] R,W DPTR1 Mode Bits 00: DPTR1 No Change 01: Reserved 10: Auto Increment 11: Auto Decrement 1-0 MD[01:00] R,W DPTR0 Mode Bits 00: DPTR0 No Change 01: Reserved 10: Auto Increment 11: Auto Decrement MOV R7, #COUNT ; initialize size of data block to transfer MOV DPTR, #SOURCE_ADDR ; load XDATA source address base into DPTR0 MOV 85h, #01h ; load DPTC to access DPTR1 pointer MOV DPTR, #DEST_ADDR ; load XDATA destination address base into DPTR1 MOV 85h, #40h ; load DPTC to access DPTR0 pointer and auto toggle MOV 86h, #0Ah ; load DPTM to auto-increment both pointers LOOP: MOVX(1) A, @DPTR ; load XDATA byte from source into ACC. ; after load completes, DPTR0 increments and DPTR ; switches DPTR1 MOVX(1) @DPTR, A ; store XDATA byte from ACC to destination. ; after store completes, DPTR1 increments and DPTR ; switches to DPTR0 DJNZ(1) R7, LOOP ; continue until done MOV 86h, #00 ; disable auto-increment MOV 85h, #00 ; disable auto-toggle, now back to single DPTR mode39/231 uPSD33xx DEBUG UNIT The 8032 MCU Module supports run-time debugging through the JTAG interface. This same JTAG interface is also used for In-System Programming (ISP) and the physical connections are described in the PSD Module section, JTAG ISP and JTAG Debug, page 195. Debugging with a serial interface such as JTAG is a non-intrusive way to gain access to the internal state of the 8032 MCU core and various memories. A traditional external hardware emulator cannot be completely effective on the uPSD33xx because of the Pre-Fetch Queue and Branch Cache. The nature of the PFQ and BC hide the visibility of actual program flow through traditional external bus connections, thus requiring on-chip serial debugging instead. Debugging is supported by Windows PC based software tools used for 8051 code development from 3rd party vendors listed at www.st.com/psm. Debug capabilities include: ■ Halt or Start MCU execution ■ Reset the MCU ■ Single Step ■ 3 Match Breakpoints ■ 1 Range Breakpoint (inside or outside range) ■ Program Tracing ■ Read or Modify MCU core registers, DATA, IDATA, SFR, XDATA, and Code ■ External Debug Event Pin, Input or Output Some key points regarding use of the JTAG Debugger. – The JTAG Debugger can access MCU registers, data memory, and code memory while the MCU is executing at full speed by cycle-stealing. This means “watch windows” may be displayed and periodically updated on the PC during full speed operation. Registers and data content may also be modified during full speed operation. – There is no on-chip storage for Program Trace data, but instead this data is scanned from the uPSD33xx through the JTAG channel at runtime to the PC host for proccessing. As such, full speed program tracing is possible only when the 8032 MCU is operating below approximately one MIPS of performance. Above one MIPS, the program will not run real-time while tracing. One MIPS performance is determined by the combination of choice for MCU clock frequency, and the bit settings in SFR registers BUSCON and CCON0. – Breakpoints can optionally halt the MCU, and/ or assert the external Debug Event pin. – Breakpoint definitions may be qualified with read or write operations, and may also be qualified with an address of code, SFR, DATA, IDATA, or XDATA memories. – Three breakpoints will compare an address, but the fourth breakpoint can compare an address and also data content. Additionally, the fouth breakpoint can be logically combined (AND/OR) with any of the other three breakpoints. – The Debug Event pin can be configured by the PC host to generate an output pulse for external triggering when a break condition is met. The pin can also be configured as an event input to the breakpoint logic, causing a break on the falling-edge of an external event signal. If not used, the Debug Event pin should be pulled up to VCC as described in the section, Debugging the 8032 MCU Module., page 201. – The duration of a pulse, generated when the Event pin configured as an output, is one MCU clock cycle. This is an active-low signal, so the first edge when an event occurs is high-to-low. – The clock to the Watchdog Timer, ADC, and I 2C interface are not stopped by a breakpoint halt. – The Watchdog Timer should be disabled while debugging with JTAG, else a reset will be generated upon a watchdog time-out.uPSD33xx 40/231 INTERRUPT SYSTEM The uPSD33xx has an 11-source, two priority level interrupt structure summarized in Table 16. Firmware may assign each interrupt source either high or low priority by writing to bits in the SFRs named, IP and IPA, shown in Table 16. An interrupt will be serviced as long as an interrupt of equal or higher priority is not already being serviced. If an interrupt of equal or higher priority is being serviced, the new interrupt will wait until it is finished before being serviced. If a lower priority interrupt is being serviced, it will be stopped and the new interrupt is serviced. When the new interrupt is finished, the lower priority interrupt that was stopped will be completed. If new interrupt requests are of the same priority level and are received simultaneously, an internal polling sequence determines which request is selected for service. Thus, within each of the two priority levels, there is a second priority structure determined by the polling sequence. Firmware may individually enable or disable interrupt sources by writing to bits in the SFRs named, IE and IEA, shown in Table 16., page 41. The SFR named IE contains a global disable bit (EA), which can be cleared to disable all 11 interrupts at once, as shown in Table 17., page 43. Figure 13., page 42 illustrates the interrupt priority, polling, and enabling process. Each interrupt source has at least one interrupt flag that indicates whether or not an interrupt is pending. These flags reside in bits of various SFRs shown in Table 16., page 41. All of the interrupt flags are latched into the interrupt control system at the beginning of each MCU machine cycle, and they are polled at the beginning of the following machine cycle. If polling determines one of the flags was set, the interrupt control system automatically generates an LCALL to the user’s Interrupt Service Routine (ISR) firmware stored in program memory at the appropriate vector address. The specific vector address for each of the interrupt sources are listed in Table 16., page 41. However, this LCALL jump may be blocked by any of the following conditions: – An interrupt of equal or higher priority is already in progress – The current machine cycle is not the final cycle in the execution of the instruction in progress – The current instruction involves a write to any of the SFRs: IE, IEA, IP, or IPA – The current instruction is an RETI Note: Interrupt flags are polled based on a sample taken in the previous MCU machine cycle. If an interrupt flag is active in one cycle but is denied serviced due to the conditions above, and then later it is not active when the conditions above are finally satisfied, the previously denied interrupt will not be serviced. This means that active interrupts are not remembered. Every poling cycle is new. Assuming all of the listed conditions are satisfied, the MCU executes the hardware generated LCALL to the appropriate ISR. This LCALL pushes the contents of the PC onto the stack (but it does not save the PSW) and loads the PC with the appropriate interrupt vector address. Program execution then jumps to the ISR at the vector address. Execution precedes in the ISR. It may be necessary for the ISR firmware to clear the pending interrupt flag for some interrupt sources, because not all interrupt flags are automatically cleared by hardware when the ISR is called, as shown in Table 16., page 41. If an interrupt flag is not cleared after servicing the interrupt, an unwanted interrupt will occur upon exiting the ISR. After the interrupt is serviced, the last instruction executed by the ISR is RETI. The RETI informs the MCU that the ISR is no longer in progress and the MCU pops the top two bytes from the stack and loads them into the PC. Execution of the interrupted program continues where it left off. Note: An ISR must end with a RETI instruction, not a RET. An RET will not inform the interrupt control system that the ISR is complete, leaving the MCU to think the ISR is still in progress, making future interrupts impossible.41/231 uPSD33xx Table 16. Interrupt Summary Interrupt Source Polling Priority Vector Addr Flag Bit Name (SFR.bit position) 1 = Intr Pending 0 = No Interrupt Flag Bit AutoCleared by Hardware? Enable Bit Name (SFR.bit position) 1 = Intr Enabled 0 = Intr Disabled Priority Bit Name (SFR.bit position) 1= High Priority 0 = Low Priority Reserved 0 (high) 0063h – – – – External Interrupt INT0 1 0003h IE0 (TCON.1) Edge - Yes Level - No EX0 (IE.0) PX0 (IP.0) Timer 0 Overflow 2 000Bh TF0 (TCON.5) Yes ET0 (IE.1) PT0 (IP.1) External Interrupt INT1 3 0013h IE1 (TCON.3 Edge - Yes Level - No EX1 (IE.2) PX1 (IP.2) Timer 1 Overflow 4 001Bh TF1 (TCON.7) Yes ET1 (IE.3) PT1 (IP.3) UART0 5 0023h RI (SCON0.0) TI (SCON0.1) No ES0 (IE.4) PS0 (IP.4) Timer 2 Overflow or TX2 Pin 6 002Bh TF2 (T2CON.7) EXF2 (T2CON.6) No ET2 (IE.5) PT2 (IP.5) SPI 7 0053h TEISF, RORISF, TISF, RISF (SPISTAT[3:0]) Yes ESPI (IEA.6) PSPI (IPA.6) Reserved 8 0033h – – – – I 2C 9 0043h INTR (S1STA.5) Yes EI2C (IEA.1) PI2C (IPA.1) ADC 10 003Bh AINTF (ACON.7) No EADC (IEA.7) PADC (IPA.7) PCA 11 005Bh OFVx, INTFx (PCASTA[0:7]) No EPCA (IEA.5) PPCA (IPA.5) UART1 12 (low) 004Bh RI (SCON1.0) TI (SCON1.1) No ES1 (IEA.4) PS1 (IPA.4)uPSD33xx 42/231 Figure 13. Enabling and Polling Interrupts Reserved Ext INT0 Ext INT1 Timer 0 UART0 Timer 1 SPI USB Timer 2 High LowInterrupt Polling Sequence Interrupt Sources IE/IEA IP/IPA Priority Global Enable ADC PCA I 2 C UART1 AI0784443/231 uPSD33xx Individual Interrupt Sources External Interrupts Int0 and Int1. External interrupt inputs on pins EXTINT0 and EXTINT1 (pins 3.2 and 3.3) are either edge-triggered or level-triggered, depending on bits IT0 and IT1 in the SFR named TCON. When an external interrupt is generated from an edge-triggered (falling-edge) source, the appropriate flag bit (IE0 or IE1) is automatically cleared by hardware upon entering the ISR. When an external interrupt is generated from a level-triggered (low-level) source, the appropriate flag bit (IE0 or IE1) is NOT automatically cleared by hardware. Timer 0 and 1 Overflow Interrupt. Timer 0 and Timer 1 interrupts are generated by the flag bits TF0 and TF1 when there is an overflow condition in the respective Timer/Counter register (except for Timer 0 in Mode 3). Timer 2 Overflow Interrupt. This interrupt is generated to the MCU by a logical OR of flag bits, TF2 and EXE2. The ISR must read the flag bits to determine the cause of the interrupt. – TF2 is set by an overflow of Timer 2. – EXE2 is generated by the falling edge of a signal on the external pin, T2X (pin P1.1). UART0 and UART1 Interrupt. Each of the UARTs have identical interrupt structure. For each UART, a single interrupt is generated to the MCU by the logical OR of the flag bits, RI (byte received) and TI (byte transmitted). The ISR must read flag bits in the SFR named SCON0 for UART0, or SCON1 for UART1 to determine the cause of the interrupt. SPI Interrupt. The SPI interrupt has four interrupt sources, which are logically ORed together when interrupting the MCU. The ISR must read the flag bits to determine the cause of the interrupt. A flag bit is set for: end of data transmit (TEISF); data receive overrun (RORISF); transmit buffer empty (TISF); or receive buffer full (RISF). I 2C Interrupt. The flag bit INTR is set by a variety of conditions occurring on the I2C interface: received own slave address (ADDR flag); received general call address (GC flag); received STOP condition (STOP flag); or successful transmission or reception of a data byte.The ISR must read the flag bits to determine the cause of the interrupt. ADC Interrupt. The flag bit AINTF is set when an A-to-D conversion has completed. PCA Interrupt. The PCA has eight interrupt sources, which are logically ORed together when interrupting the MCU.The ISR must read the flag bits to determine the cause of the interrupt. – Each of the six TCMs can generate a "match or capture" interrupt on flag bits OFV5..0 respectively. – Each of the two 16-bit counters can generate an overflow interrupt on flag bits INTF1 and INTF0 respectively. Tables 17 through Table 20., page 45 have detailed bit definitions of the interrupt system SFRs. Table 17. IE: Interrupt Enable Register (SFR A8h, reset value 00h) Note: 1. 1 = Enable Interrupt, 0 = Disable Interrupt Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 EA – ET2 ES0 ET1 EX1 ET0 EX0 Details Bit Symbol R/W Function 7 EA R,W Global disable bit. 0 = All interrupts are disabled. 1 = Each interrupt source can be individually enabled or disabled by setting or clearing its enable bit. 6 – R,W Do not modify this bit. It is used by the JTAG debugger for instruction tracing. Always read the bit and write back the same bit value when writing this SFR. 5(1) ET2 R,W Enable Timer 2 Interrupt 4(1) ES0 R,W Enable UART0 Interrupt 3(1) ET1 R,W Enable Timer 1 Interrupt 2(1) EX1 R,W Enable External Interrupt INT1 1(1) ET0 R,W Enable Timer 0 Interrupt 0(1) EX0 R,W Enable External Interrupt INT0uPSD33xx 44/231 Table 18. IEA: Interrupt Enable Addition Register (SFR A7h, reset value 00h) Note: 1. 1 = Enable Interrupt, 0 = Disable Interrupt Table 19. IP: Interrupt Priority Register (SFR B8h, reset value 00h) Note: 1. 1 = Assigns high priority level, 0 = Assigns low priority level Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 EADC ESPI EPCA ES1 – – EI2C – Details Bit Symbol R/W Function 7(1) EADC R,W Enable ADC Interrupt 6(1) ESPI R,W Enable SPI Interrupt 5(1) EPCA R,W Enable Programmable Counter Array Interrupt 4(1) ES1 R,W Enable UART1 Interrupt 3 – – Reserved, do not set to logic '1.' 2 – – Reserved, do not set to logic '1.' 1(1) EI2C R,W Enable I2C Interrupt 0 – – Reserved, do not set to logic '1.' Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – PT2 PS0 PT1 PX1 PT0 PX0 Details Bit Symbol R/W Function 7 – – Reserved 6 – – Reserved 5(1) PT2 R,W Timer 2 Interrupt priority level 4(1) PS0 R,W UART0 Interrupt priority level 3(1) PT1 R,W Timer 1 Interrupt priority level 2(1) PX1 R,W External Interrupt INT1 priority level 1(1) PT0 R,W Timer 0 Interrupt priority level 0(1) PX0 R,W External Interrupt INT0 priority level45/231 uPSD33xx Table 20. IPA: Interrupt Priority Addition register (SFR B7h, reset value 00h) Note: 1. 1 = Assigns high priority level, 0 = Assigns low priority level Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PADC PSPI PPCA PS1 – – PI2C – Details Bit Symbol R/W Function 7(1) PADC R,W ADC Interrupt priority level 6(1) PSPI R,W SPI Interrupt priority level 5(1) PPCA R,W PCA Interrupt level 4(1) PS1 R,W UART1 Interrupt priority level 3 – – Reserved 2 – – Reserved 1(1) PI2C R,W I 2C Interrupt priority level 0 – – ReserveduPSD33xx 46/231 MCU CLOCK GENERATION Internal system clocks generated by the clock generation unit are derived from the signal, XTAL1, shown in Figure 14. XTAL1 has a frequency fOSC, which comes directly from the external crystal or oscillator device. The SFR named CCON0 (Table 21., page 47) controls the clock generation unit. There are two clock signals produced by the clock generation unit: ■ MCU_CLK ■ PERIPH_CLK MCU_CLK This clock drives the 8032 MCU core and the Watchdog Timer (WDT). The frequency of MCU_CLK is equal to fOSC by default, but it can be divided by as much as 2048, shown in Figure 14. The bits CPUPS[2:0] select one of eight different divisors, ranging from 2 to 2048. The new frequency is available immediately after the CPUPS[2:0] bits are written. The final frequency of MCU_CLK is fMCU. MCU_CLK is blocked by either bit, PD or IDL, in the SFR named PCON during MCU Power-down Mode or Idle Mode respectively. MCU_CLK clock can be further divided as required for use in the WDT. See details of the WDT in SUPERVISORY FUNCTIONS, page 65. PERIPH_CLK This clock drives all the uPSD33xx peripherals except the WDT. The Frequency of PERIPH_CLK is always fOSC. Each of the peripherals can independently divide PERIPH_CLK to scale it appropriately for use. PERIPH_CLK runs at all times except when blocked by the PD bit in the SFR named PCON during MCU Power-down Mode. JTAG Interface Clock. The JTAG interface for ISP and for Debugging uses the externally supplied JTAG clock, coming in on pin TCK. This means the JTAG ISP interface is always available, and the JTAG Debug interface is available when enabled, even during MCU Idle mode and Powerdown Mode. However, since the MCU participates in the JTAG debug process, and MCU_CLK is halted during Idle and Power-down Modes, the majority of debug functions are not available during these low power modes. But the JTAG debug interface is capable of executing a reset command while in these low power modes, which will exit back to normal operating mode where all debug commands are available again. The CCON0 SFR contains a bit, DBGCE, which enables the breakpoint comparators inside the JTAG Debug Unit when set. DBGCE is set by default after reset, and firmware may clear this bit at run-time. Disabling these comparators will reduce current consumption on the MCU Module, and it’s recommended to do so if the Debug Unit will not be used (such as in the production version of an end-product). Figure 14. Clock Generation Logic XTAL1 /2 XTAL1 /4 XTAL1 /2048 Q Q Q M U X XTAL1 (default) XTAL1 /8 XTAL1 /16 Q Q XTAL1 /32 XTAL1 /1024 Q Q 0 1 2 3 4 5 6 7 XTAL1 (fOSC) PCON[1]: PD, Power-Down Mode PCON[2:0]: CPUPS[2:0], Clock Pre-Scaler Select PCON[0]: IDL, Idle Mode Clock Divider MCU_CLK (fMCU) (to: 8032, WDT) PERIPH_CLK (fOSC) (to: TIMER0/1/2, UART0/1, PCA0/1, SPI, I2C, ADC) 3 AI0919747/231 uPSD33xx Table 21. CCON0: Clock Control Register (SFR F9h, reset value 10h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – – DBGCE CPUAR CPUPS[2:0] Details Bit Symbol R/W Definition 7 – – Reserved 6 – – Reserved 5 – – Reserved 4 DBGCE R,W Debug Unit Breakpoint Comparator Enable 0 = JTAG Debug Unit comparators are disabled 1 = JTAG Debug Unit comparators are enabled (Default condition after reset) 3 CPUAR R,W Automatic MCU Clock Recovery 0 = There is no change of CPUPS[2:0] when an interrupt occurs. 1 = Contents of CPUPS[2:0] automatically become 000b whenever any interrupt occurs. 2:0 CPUPS R,W MCUCLK Pre-Scaler 000b: fMCU = fOSC (Default after reset) 001b: fMCU = fOSC/2 010b: fMCU = fOSC/4 011b: fMCU = fOSC/8 100b: fMCU = fOSC/16 101b: fMCU = fOSC/32 110b: fMCU = fOSC/1024 111b: fMCU = fOSC/2048uPSD33xx 48/231 POWER SAVING MODES The uPSD33xx is a combination of two die, or modules, each module having it’s own current consumption characteristics. This section describes reduced power modes for the MCU Module. See the section, Power Management, page 137 for reduced power modes of the PSD Module. Total current consumption for the combined modules is determined in the DC specifications at the end of this document. The MCU Module has three software-selectable modes of reduced power operation. ■ Idle Mode ■ Power-down Mode ■ Reduced Frequency Mode Idle Mode Idle Mode will halt the 8032 MCU core while leaving the MCU peripherals active (Idle Mode blocks MCU_CLK only). For lowest current consumption in this mode, it is recommended to disable all unused peripherals, before entering Idle mode (such as the ADC and the Debug Unit breakpoint comparators). The following functions remain fully active during Idle Mode (except if disabled by SFR settings). ■ External Interrupts INT0 and INT1 ■ Timer 0, Timer 1 and Timer 2 ■ Supervisor reset from: LVD, JTAG Debug, External RESET_IN_, but not the WTD ■ ADC ■ I 2C Interface ■ UART0 and UART1 Interfaces ■ SPI Interface ■ Programmable Counter Array An interrupt generated by any of these peripherals, or a reset generated from the supervisor, will cause Idle Mode to exit and the 8032 MCU will resume normal operation. The output state on I/O pins of MCU ports 1, 3, and 4 remain unchanged during Idle Mode. To enter Idle Mode, the 8032 MCU executes an instruction to set the IDL bit in the SFR named PCON, shown in Table 24., page 50. This is the last instruction executed in normal operating mode before Idle Mode is activated. Once in Idle Mode, the MCU status is entirely preserved, and there are no changes to: SP, PSW, PC, ACC, SFRs, DATA, IDATA, or XDATA. The following are factors related to Idle Mode exit: – Activation of any enabled interrupt will cause the IDL bit to be cleared by hardware, terminating Idle Mode. The interrupt is serviced, and following the Return from Interrupt instruction (RETI), the next instruction to be executed will be the one which follows the instruction that set the IDL bit in the PCON SFR. – After a reset from the supervisor, the IDL bit is cleared, Idle Mode is terminated, and the MCU restarts after three MCU machine cycles. Power-down Mode Power-down Mode will halt the 8032 core and all MCU peripherals (Power-down Mode blocks MCU_CLK and PERIPH_CLK). This is the lowest power state for the MCU Module. When the PSD Module is also placed in Power-down mode, the lowest total current consumption for the combined die is achieved for the uPSD33xx. See Power Management, page 137 in the PSD Module section for details on how to also place the PSD Module in Power-down mode. The sequence of 8032 instructions is important when placing both modules into Power-down Mode. The instruction that sets the PD Bit in the SFR named PCON (Table 24., page 50) is the last instruction executed prior to the MCU Module going into Power-down Mode. Once in Power-down Mode, the on-chip oscillator circuitry and all clocks are stopped. The SFRs, DATA, IDATA, and XDATA are preserved. Power-down Mode is terminated only by a reset from the supervisor, originating from the RESET_IN_ pin, the Low-Voltage Detect circuit (LVD), or a JTAG Debug reset command. Since the clock to the WTD is not active during Powerdown mode, it is not possible for the supervisor to generate a WDT reset. Table 22., page 49 summarizes the status of I/O pins and peripherals during Idle and Power-down Modes on the MCU Module. Table 23., page 49 shows the state of 8032 MCU address, data, and control signals during these modes. Reduced Frequency Mode The 8032 MCU consumes less current when operating at a lower clock frequency. The MCU can reduce it’s own clock frequency at run-time by writing to three bits, CPUPS[2:0], in the SFR named CCON0 described in Table 21., page 47. These bits effectively divide the clock frequency (fOSC) coming in from the external crystal or oscillator device. The clock division range is from 1/2 to 1/2048, and the resulting frequency is fMCU. This MCU clock division does not affect any of the peripherals, except for the WTD. The clock driving the WTD is the same clock driving the 8032 MCU core as shown in Figure 14., page 46.49/231 uPSD33xx MCU firmware may reduce the MCU clock frequency at run-time to consume less current when performing tasks that are not time critical, and then restore full clock frequency as required to perform urgent tasks. Returning to full clock frequency is done automatically upon an MCU interrupt, if the CPUAR Bit in the SFR named CCON0 is set (the interrupt will force CPUPS[2:0] = 000). This is an excellent way to conserve power using a low frequency clock until an event occurs that requires full performance. See Table 21., page 47 for details on CPUAR. See the DC Specifications at the end of this document to estimate current consumption based on the MCU clock frequency. Note: Some of the bits in the PCON SFR shown in Table 24., page 50 are not related to power control. Table 22. MCU Module Port and Peripheral Status during Reduced Power Modes Note: 1. The Watchdog Timer is not active during Idle Mode. Other supervisor functions are active: LVD, external reset, JTAG Debug reset Table 23. State of 8032 MCU Bus Signals during Power-down and Idle Modes Mode Ports 1, 3, 4 PCA SPI I 2C ADC SUPERVISOR UART0, UART1 TIMER 0,1,2 EXT INT0, 1 Idle Maintain Data Active Active Active Active Active(1) Active Active Active Power-down Maintain Data Disabled Disabled Disabled Disabled Disabled Disabled Disabled Disabled Mode ALE PSEN_ RD_ WR_ AD0-7 A8-15 Idle 0 1 1 1 FFh FFh Power-down 0 1 1 1 FFh FFhuPSD33xx 50/231 Table 24. PCON: Power Control Register (SFR 87h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SMOD0 SMOD1 – POR RCLK1 TCLK1 PD IDL Details Bit Symbol R/W Function 7 SMOD0 R,W Baud Rate Double Bit (UART0) 0 = No Doubling 1 = Doubling (See UART Baud Rates, page 84 for details.) 6 SMOD1 R,W Baud Rate Double Bit for 2nd UART (UART1) 0 = No Doubling 1 = Doubling (See UART Baud Rates, page 84 for details.) 5 – – Reserved 4 POR R,W Only a power-on reset sets this bit (cold reset). Warm reset will not set this bit. '0,' Cleared to zero with firmware '1,' Is set only by a power-on reset generated by Supervisory circuit (see Power-up Reset, page 66 for details). 3 RCLK1 R,W Received Clock Flag (UART1) (See Table 41., page 75 for flag description.) 2 TCLK1 R,W Transmit Clock Flag (UART1) (See Table 41., page 75 for flag description) 1 PD R,W Activate Power-down Mode 0 = Not in Power-down Mode 1 = Enter Power-down Mode 0 IDL R,W Activate Idle Mode 0 = Not in Idle Mode 1 = Enter Idle Mode51/231 uPSD33xx OSCILLATOR AND EXTERNAL COMPONENTS The oscillator circuit of uPSD33xx devices is a single stage, inverting amplifier in a Pierce oscillator configuration. The internal circuitry between pins XTAL1 and XTAL2 is basically an inverter biased to the transfer point. Either an external quartz crystal or ceramic resonator can be used as the feedback element to complete the oscillator circuit. Both are operated in parallel resonance. Ceramic resonators are lower cost, but typically have a wider frequency tolerance than quartz crystals. Alternatively, an external clock source from an oscillator or other active device may drive the uPSD33xx oscillator circuit input directly, instead of using a crystal or resonator. The minimum frequency of the quartz crystal, ceramic resonator, or external clock source is 1MHz if the I2C interface is not used. The minimum is 8MHz if I2C is used. The maximum is 40MHz in all cases. This frequency is fOSC, which can be divided internally as described in MCU CLOCK GENERATION, page 46. The pin XTAL1 is the high gain amplifier input, and XTAL2 is the output. To drive the uPSD33xx device externally from an oscillator or other active device, XTAL1 is driven and XTAL2 is left opencircuit. This external source should drive a logic low at the voltage level of 0.3 VCC or below, and logic high at 0.7V VCC or above, up to 5.5V VCC. The XTAL1 input is 5V tolerant. Most of the quartz crystals in the range of 25MHz to 40MHz operate in the third overtone frequency mode. An external LC tank circuit at the XTAL2 output of the oscillator circuit is needed to achieve the third overtone frequency, as shown in Figure 15., page 52. Without this LC circuit, the crystal will oscillate at a fundamental frequency mode that is about 1/3 of the desired overtone frequency. Note: In Figure 15., page 52 crystals which are specified to operate in fundamental mode (not overtone mode) do not need the LC circuit components. Since quartz crystals and ceramic resonators have their own characteristics based on their manufacturer, it is wise to also consult the manufacturer’s recommended values for external components.uPSD33xx 52/231 Figure 15. Oscillator and Clock Connections Crystal or Resonator Usage Direct Drive XTAL1 (in) XTAL1 (in) XTAL2 (out) XTAL2 (out) C1 C2 XTAL (fOSC) L1 C3 External Ocsillator or No Connect Active Clock Source XTAL (fOSC) C1 = C2 C3 L1 Ceramic Resonator 40 - 50pF None Crystal, fundamental mode (3-40MHz) 15-33pF None None None Crystal, overtone mode (25-40MHz) 20pF 10nF 2.2µH AI0919853/231 uPSD33xx I/O PORTS OF MCU MODULE The MCU Module has three 8-bit I/O ports: Port 1, Port 3, and Port 4. The PSD Module has four other I/O ports: Port A, B, C, and D. This section describes only the I/O ports on the MCU Module. I/O ports will function as bi-directional General Purpose I/O (GPIO), but the port pins can have alternate functions assigned at run-time by writing to specific SFRs. The default operating mode (during and after reset) for all three ports is GPIO input mode. Port pins that have no external connection will not float because each pin has an internal weak pull-up (~150K ohms) to VCC. I/O ports 3 and 4 are 5V tolerant, meaning they can be driven/pulled externally up to 5.5V without damage. The pins on Port 4 have a higher current capability than the pins on Ports 1 and 3. Three additional MCU ports (only on 80-pin uPSD33xx devices) are dedicated to bring out the 8032 MCU address, data, and control signals to external pins. One port, named MCUA[11:8], contains four MCU address signal outputs. Another port, named MCUAD[7:0], has eight multiplexed address/data bidirectional signals. The third port has MCU bus control outputs: read, write, program fetch, and address latch. These ports are typically used to connect external parallel peripherals and memory devices, but they may NOT be used as GPIO. Notice that only four of the eight upper address signals come out to pins on the port MCUA[11:8]. If additional high-order address signals are required on external pins (MCU addresses A[15:12]), then these address signals can be brought out as needed to PLD output pins or to the Address Out mode pins on PSD Module ports. See PSD Module section, “Latched Address Output Mode, page 177 for details. Figure 16., page 55 represents the flexibility of pin function routing controlled by the SFRs. Each of the 24 pins on three ports, P1, P3, and P4, may be individually routed on a pin-by-pin basis to a desired function. MCU Port Operating Modes MCU port pins can operate as GPIO or as alternate functions (see Figure 17., page 56 through Figure 19., page 57). Depending on the selected pin function, a particular pin operating mode will automatically be used: ■ GPIO - Quasi-bidirectional mode ■ UART0, UART1 - Quasi-bidirectional mode ■ SPI - Quasi-bidirectional mode ■ I2C - Open drain mode ■ ADC - Analog input mode ■ PCA output - Push-Pull mode ■ PCA input - Input only (Quasi-bidirectional) ■ Timer 0,1,2 - Input only (Quasi-bidirectional) GPIO Function. Ports in GPIO mode operate as quasi-bidirectional pins, consistent with standard 8051 architecture. GPIO pins are individually controlled by three SFRs: ■ SFR, P1 (Table 25., page 57) ■ SFR, P3 (Table 26., page 58) ■ SFR, P4 (Table 27., page 58) These SFRs can be accessed using the Bit Addressing mode, an efficient way to control individual port pins. GPIO Output. Simply stated, when a logic '0' is written to a bit in any of these port SFRs while in GPIO mode, the corresponding port pin will enable a low-side driver, which pulls the pin to ground, and at the same time releases the high-side driver and pull-ups, resulting in a logic'0' output. When a logic '1' is written to the SFR, the low-side driver is released, the high-side driver is enabled for just one MCU_CLK period to rapidly make the 0-to1 transition on the pin, while weak active pull-ups (total ~150K ohms) to VCC are enabled. This structure is consistent with standard 8051 architecture. The high side driver is momentarily enabled only for 0-to-1 transitions, which is implemented with the delay function at the latch output as pictured in Figure 17., page 56 through Figure 19., page 57. After the high-side driver is disabled, the two weak pull-ups remain enabled resulting in a logic '1' output at the pin, sourcing IOH uA to an external device. Optionally, an external pull-up resistor can be added if additional source current is needed while outputting a logic '1.'uPSD33xx 54/231 GPIO Input. To use a GPIO port pin as an input, the low-side driver to ground must be disabled, or else the true logic level being driven on the pin by an external device will be masked (always reads logic '0'). So to make a port pin “input ready”, the corresponding bit in the SFR must have been set to a logic '1' prior to reading that SFR bit as an input. A reset condition forces SFRs P1, P3, and P4 to FFh, thus all three ports are input ready after reset. When a pin is used as an input, the stronger pullup “A” maintains a solid logic '1' until an external device drives the input pin low. At this time, pull-up “A” is automatically disabled, and only pull-up “B” will source the external device IIH uA, consistent with standard 8051 architecture. GPIO Bi-Directional. It is possible to operate individual port pins in bi-directional mode. For an output, firmware would simply write the corresponding SFR bit to logic '1' or '0' as needed. But before using the pin as an input, firmware must first ensure that a logic '1' was the last value written to the corresponding SFR bit prior to reading that SFR bit as an input. GPIO Current Capability. A GPIO pin on Port 4 can sink twice as much current than a pin on either Port 1 or Port 3 when the low-side driver is outputting a logic '0' (IOL). See the DC specifications at the end of this document for full details. Reading Port Pin vs. Reading Port Latch. When firmware reads the GPIO ports, sometimes the actual port pin is sampled in hardware, and sometimes the port SFR latch is read and not the actual pin, depending on the type of MCU instruction used. These two data paths are shown in Figure 17., page 56 through Figure 19., page 57. SFR latches are read (and not the pins) only when the read is part of a read-modify-write instruction and the write destination is a bit or bits in a port SFR. These instructions are: ANL, ORL, XRL, JBC, CPL, INC, DEC, DJNZ, MOV, CLR, and SETB. All other types of reads to port SFRs will read the actual pin logic level and not the port latch. This is consistent with 8051 architecture.55/231 uPSD33xx Figure 16. MCU Module Port Pin Function Routing 8 P3 P1 P4 M C U A D M C U A GPIO (8) UART0 (2) TIMER0/1 (4) I 2C (2) GPIO (8) GPIO (8) TIMER2 (2) UART1 (2) SPI (4) ADC (8) PCA (8) 8032 MCU CORE Low Addr & Data[7:0] 8 Available on PSD Hi Address [15:12] Hi Address [11:8] 4 Module Pins MCU Module 4 On 80-pin Devices Only Ports C N T L RD, WR, PSEN, ALE 4 SFR 8 8 SFR SFR SFR SFR SFR AI09199uPSD33xx 56/231 Figure 17. MCU I/O Cell Block Diagram for Port 1 Figure 18. MCU I/O Cell Block Diagram for Port 3 P1.X Pin Analog_Alt_Func_En Analog_Pin_In D Q PRE SFR P1.X Latch 8032 Data Bus Bit GPIO P1.X SFR Write Latch MCU_Reset P1.X SFR Read Latch (for R-M-W instructions) P1.X SFR Read Pin Select_Alternate_Func Digital_Pin_Data_In IN 1 IN 0 MUX Y VCC VCC VCC SEL WEAK PULL-UP, B STONGER PULL-UP, A LOW SIDE HIGH SIDE DELAY, 1 MCU_CLK DELAY, 1 MCU_CLK Q Digital_Alt_Func_Data_Out AI09600 P3.X Pin Digital_Pin_Data_In D Q PRE SFR P3.X Latch 8032 Data Bus Bit GPIO P3.X SFR Write Latch MCU_Reset P3.X SFR Read Latch (for R-M-W instructions) P3.X SFR Read Pin Select_Alternate_Func Disables High-Side Driver IN 1 IN 0 MUX Y VCC VCC VCC SEL Enable_I2C WEAK PULL-UP, B STONGER PULL-UP, A LOW SIDE HIGH SIDE DELAY, 1 MCU_CLK DELAY, 1 MCU_CLK Q Digital_Alt_Func_Data_Out AI0960157/231 uPSD33xx Figure 19. MCU I/O Cell Block Diagram for Port 4 Table 25. P1: I/O Port 1 Register (SFR 90h, reset value FFh) Note: 1. Write '1' or '0' for pin output. Read for pin input, but prior to READ, this bit must have been set to '1' by firmware or by a reset event. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P1.7 P1.6 P1.5 P1.4 P1.3 P1.2 P1.1 P1.0 Details Bit Symbol R/W Function(1) 7 P1.7 R,W Port pin 1.7 6 P1.6 R,W Port pin 1.6 5 P1.5 R,W Port pin 1.5 4 P1.4 R,W Port pin 1.4 3 P1.3 R,W Port pin 1.3 2 P1.2 R,W Port pin 1.2 1 P1.1 R,W Port pin 1.1 0 P1.0 R,W Port pin 1.0 P4.X Pin Digital_Pin_Data_In D Q PRE SFR P4.X Latch 8032 Data Bus Bit GPIO P4.X SFR Write Latch MCU_Reset P4.X SFR Read Latch (for R-M-W instructions) P4.X SFR Read Pin Select_Alternate_Func For PCA Alternate Function IN 1 IN 0 MUX Y VCC VCC VCC SEL Enable_Push_Pull WEAK PULL-UP, B STONGER PULL-UP, A LOW SIDE HIGH SIDE DELAY, 1 MCU_CLK DELAY, 1 MCU_CLK Q Digital_Alt_Func_Data_Out AI09602uPSD33xx 58/231 Table 26. P3: I/O Port 3 Register (SFR B0h, reset value FFh) Note: 1. Write '1' or '0' for pin output. Read for pin input, but prior to READ, this bit must have been set to '1' by firmware or by a reset event. Table 27. P4: I/O Port 4 Register (SFR C0h, reset value FFh) Note: 1. Write '1' or '0' for pin output. Read for pin input, but prior to READ, this bit must have been set to '1' by firmware or by a reset event. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P3.7 P3.6 P3.5 P3.4 P3.3 P3.2 P3.1 P3.0 Details Bit Symbol R/W Function(1) 7 P3.7 R,W Port pin 3.7 6 P3.6 R,W Port pin 3.6 5 P3.5 R,W Port pin 3.5 4 P3.4 R,W Port pin 3.4 3 P3.3 R,W Port pin 3.3 2 P3.2 R,W Port pin 3.2 1 P3.1 R,W Port pin 3.1 0 P3.0 R,W Port pin 3.0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P4.7 P4.6 P4.5 P4.4 P4.3 P4.2 P4.1 P4.0 Details Bit Symbol R/W Function(1) 7 P4.7 R,W Port pin 4.7 6 P4.6 R,W Port pin 4.6 5 P4.5 R,W Port pin 4.5 4 P4.4 R,W Port pin 4.4 3 P4.3 R,W Port pin 4.3 2 P4.2 R,W Port pin 4.2 1 P4.1 R,W Port pin 4.1 0 P4.0 R,W Port pin 4.059/231 uPSD33xx Alternate Functions. There are five SFRs used to control the mapping of alternate functions onto MCU port pins, and these SFRs are depicted as switches in Figure 16., page 55. ■ Port 3 uses the SFR, P3SFS (Table 28., page 60). ■ Port 1 uses SFRs, P1SFS0 (Table 29., page 60) and P1SFS1 (Table 30., page 60). ■ Port 4 uses SFRs, P4SFS0 (Table 32., page 61) and P4SFS1 (Table 33., page 61). Since these SFRs are cleared by a reset, then by default all port pins function as GPIO (not the alternate function) until firmware initializes these SFRs. Each pin on each of the three ports can be independently assigned a different function on a pinby-pin basis. The peripheral functions Timer 2, UART1, and I2C may be split independently between Port 1 and Port 4 for additional flexibility by giving a wider choice of peripheral usage on a limited number of device pins. When the selected alternate function is UART0, UART1, or SPI, then the related pins are in quasibidirectional mode, including the use of the highside driver for rapid 0-to-1 output transitions. The high-side driver is enabled for just one MCU_CLK period on 0-to-1 transitions by the delay function at the “digital_alt_func_data_out” signal pictured in Figure 17., page 56 through Figure 19., page 57. If the alternate function is Timer 0, Timer 1, Timer 2, or PCA input, then the related pins are in quasibidirectional mode, but input only. If the alternate function is ADC, then for each pin the pull-ups, the high-side driver, and the low-side driver are disabled. The analog input is routed directly to the ADC unit. Only Port 1 supports analog functions (Figure 17., page 56). Port 1 is not 5V tolerant. If the alternate function is I2C, the related pins will be in open drain mode, which is just like quasi-bidirectional mode but the high-side driver is not enabled for one cycle when outputting a 0-to-1 transition. Only the low-side driver and the internal weak pull-ups are used. Only Port 3 supports open-drain mode (Figure 18., page 56). I2C requires the use of an external pull-up resistor on each bus signal, typically 4.7KΩ to VCC. If the alternate function is PCA output, then the related pins are in push-pull mode, meaning the pins are actively driven and held to logic '1' by the highside driver, or actively driven and held to logic '0' by the low-side driver. Only Port 4 supports pushpull mode (Figure 19., page 57). Port 4 push-pull pins can source IOH current when driving logic '1,' and sink IOL current when driving logic '0.' This current is significantly more than the capability of pins on Port 1 or Port 3 (see Table 129., page 207). For example, to assign these port functions: ■ Port 1: UART1, ADC[1:0], P1[7:4] are GPIO ■ Port 3: UART0, I2C, P3[5:2] are GPIO ■ Port 4: TCM0, SPI, P4[3:1] are GPIO The following values need to be written to the SFRs: P1SFS0 = 00001111b, or 0Fh P1SFS1 = 00000011b , or 03h P3SFS = 11000011b, or C3h P4SFS0 = 11110001b, or F1h P4SFS1 = 11110000b, or F0huPSD33xx 60/231 Table 28. P3SFS: Port 3 Special Function Select Register (SFR 91h, reset value 00h) Table 29. P1SFS0: Port 1 Special Function Select 0 Register (SFR 8Eh, reset value 00h) Table 30. P1SFS1: Port 1 Special Function Select 1 Register (SFR 8Fh, reset value 00h) Table 31. P1SFS0 and P1SFS1 Details Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P3SFS7 P3SFS6 P3SFS5 P3SFS4 P3SFS3 P3SFS2 P3SFS1 P3SFS0 Details Port 3 Pin R/W Default Port Function Alternate Port Function P3SFS[i] - 0; Port 3 Pin, i = 0..7 P3SFS[i] - 1; Port 3 Pin, i = 0..7 0 R,W GPIO UART0 Receive, RXD0 1 R,W GPIO UART0 Transmit, TXD0 2 R,W GPIO Ext Intr 0/Timer 0 Gate, EXT0INT/TG0 3 R,W GPIO Ext Intr 1/Timer 1 Gate, EXT1INT/TG1 4 R,W GPIO Counter 0 Input, C0 5 R,W GPIO Counter 0 Input, C1 6 R,W GPIO I 2C Data, I2CSDA 7 R,W GPIO I 2C Clock, I2CCL Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P1SF07 P1SF06 P1SF05 P1SF04 P1SF03 P1SF02 P1SF01 P1SF00 Details Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P1SF17 P1SF16 P1SF15 P1SF14 P1SF13 P1SF12 P1SF11 P1SF10 Port 1 Pin R/W Default Port Function Alternate 1 Port Function Alternate 2 Port Function P1SFS0[i] = 0 P1SFS1[i] = x P1SFS0[i] = 1 P1SFS1[i] = 0 P1SFS0[i] = 1 P1SFS1[i] = 1 Port 1 Pin, i = 0.. 7 Port 1 Pin, i = 0.. 7 Port 1 Pin, i = 0.. 7 0 R,W GPIO Timer 2 Count Input, T2 ADC Chn 0 Input, ADC0 1 R,W GPIO Timer 2 Trigger Input, TX2 ADC Chn 1 Input, ADC1 2 R,W GPIO UART1 Receive, RXD1 ADC Chn 2 Input, ADC2 3 R,W GPIO UART1 Transmit, TXD1 ADC Chn 3 Input, ADC3 4 R,W GPIO SPI Clock, SPICLK ADC Chn 4 Input, ADC4 5 R,W GPIO SPI Receive, SPIRXD ADC Chn 5 Input, ADC5 6 R,W GPIO SPI Transmit, SPITXD ADC Chn 6 Input, ADC6 7 R,W GPIO SPI Select, SPISEL_ ADC Chn 7 Input, ADC761/231 uPSD33xx Table 32. P4SFS0: Port 4 Special Function Select 0 Register (SFR 92h, reset value 00h) Table 33. P4SFS1: Port 4 Special Function Select 1 Register (SFR 93h, reset value 00h) Table 34. P4SFS0 and P4SFS1 Details Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P4SF07 P4SF06 P4SF05 P4SF04 P4SF03 P4SF02 P4SF01 P4SF00 Details Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 P4SF17 P4SF16 P4SF15 P4SF14 P4SF13 P4SF12 P4SF11 P4SF10 Port 4 Pin R/W Default Port Function Alternate 1 Port Function Alternate 2 Port Function P4SFS0[i] = 0 P4SFS1[i] = x P4SFS0[i] = 1 P4SFS1[i] = 0 P4SFS0[i] = 1 P4SFS1[i] = 1 Port 4 Pin, i = 0.. 7 Port 4 Pin, i = 0.. 7 Port 4 Pin, i = 0.. 7 0 R,W GPIO PCA0 Module 0, TCM0 Timer 2 Count Input, T2 1 R,W GPIO PCA0 Module 1, TCM1 Timer 2 Trigger Input, TX2 2 R,W GPIO PCA0 Module 2, TCM2 UART1 Receive, RXD1 3 R,W GPIO PCA0 Ext Clock, PCACLK0 UART1 Transmit, TXD1 4 R,W GPIO PCA1 Module 3, TCM3 SPI Clock, SPICLK 5 R,W GPIO PCA1 Module 4, TCM4 SPI Receive, SPIRXD 6 R,W GPIO PCA1 Module 5, TCM5 SPI Transmit, SPITXD 7 R,W GPIO PCA1 Ext Clock, PCACLK1 SPI Select, SPISEL_uPSD33xx 62/231 MCU BUS INTERFACE The MCU Module has a programmable bus interface. It is based on a standard 8032 bus, with eight data signals multiplexed with eight low-order address signals (AD[7:0]). It also has eight high-order non-multiplexed address signals (A[15:8]). Time multiplexing is controlled by the address latch signal, ALE. This bus connects the MCU Module to the PSD Module, and also connects to external pins only on 80-pin devices. See the AC specifications section at the end of this document for external bus timing on 80-pin devices. Four types of data transfers are supported, each transfer is to/from a memory location external to the MCU Module: – Code Fetch cycle using the PSEN signal: fetch a code byte for execution – Code Read cycle using PSEN: read a code byte using the MOVC (Move Constant) instruction – XDATA Read cycle using the RD signal: read a data byte using the MOVX (Move eXternal) instruction – XDATA Write cycle using the WR signal: write a data byte using the MOVX instruction The number of MCU_CLK periods for these transfer types can be specified at runtime by firmware writing to the SFR register named BUSCON (Table 35., page 63). Here, the number of MCU_CLK clock pulses per bus cycle are specified to maximize performance. Important: By default, the BUSCON Register is loaded with long bus cycle times (6 MCU_CLK periods) after a reset condition. It is important that the post-reset initialization firmware sets the bus cycle times appropriately to get the most performance, according to Table 36., page 64. Keep in mind that the PSD Module has a faster Turbo Mode (default) and a slower but less power consuming Non-Turbo Mode. The bus cycle times must be programmed in BUSCON to optimize for each mode as shown in Table 36., page 64. See PLD NonTurbo Mode, page 192 for more details. Bus Read Cycles (PSEN or RD) When the PSEN signal is used to fetch a byte of code, the byte is read from the PSD Module or external device and it enters the MCU Pre-Fetch Queue (PFQ). When PSEN is used during a MOVC instruction, or when the RD signal is used to read a byte of data, the byte is routed directly to the MCU, bypassing the PFQ. Bits in the BUSCON Register determine the number of MCU_CLK periods per bus cycle for each of these kinds of transfers to all address ranges. It is not possible to specify in the BUSCON Register a different number of MCU_CLK periods for various address ranges. For example, the user cannot specify 4 MCU_CLK periods for RD read cycles to one address range on the PSD Module, and 5 MCU_CLK periods for RD read cycles to a different address range on an external device. However, the user can specify one number of clock periods for PSEN read cycles and a different number of clock periods for RD read cycles. Note 1: A PSEN bus cycle in progress may be aborted before completion if the PFQ and Branch Cache (BC) determines the current code fetch cycle is not needed. Note 2: Whenever the same number of MCU_CLK periods is specified in BUSCON for both PSEN and RD cycles, the bus cycle timing is typically identical for each of these types of bus cycles. In this case, the only time PSEN read cycles are longer than RD read cycles is when the PFQ issues a stall while reloading. PFQ stalls do not affect RD read cycles. By comparison, in many traditional 8051 architectures, RD bus cycles are always longer than PSEN bus cycles. Bus Write Cycles (WR) When the WR signal is used, a byte of data is written directly to the PSD Module or external device, no PFQ or caching is involved. Bits in the BUSCON Register determine the number of MCU_CLK periods for bus write cycles to all addresses. It is not possible to specify in BUSCON a different number of MCU_CLK periods for writes to various address ranges. Controlling the PFQ and BC The BUSCON Register allows firmware to enable and disable the PFQ and BC at run-time. Sometimes it may be desired to disable the PFQ and BC to ensure deterministic execution. The dynamic action of the PFQ and BC may cause varying program execution times depending on the events that happen prior to a particular section of code of interest. For this reason, it is not recommended to implement timing loops in firmware, but instead use one of the many hardware timers in the uPSD33xx. By default, the PFQ and BC are enabled after a reset condition. Important: Disabling the PFQ or BC will seriously reduce MCU performance.63/231 uPSD33xx Table 35. BUSCON: Bus Control Register (SFR 9Dh, reset value EBh) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 EPFQ EBC WRW[1:0] RDW[1:0] CW[1:0] Details Bit Symbol R/W Definition 7 EPFQ R,W Enable Pre-Fetch Queue 0 = PFQ is disabled 1 = PFQ is enabled (default) 6 EBC R,W Enable Branch Cache 0 = BC is disabled 1 = BC is enabled (default) 5:4 WRW[1:0] R,W WR Wait, number of MCU_CLK periods for WR write bus cycle during any MOVX instruction 00b: 4 clock periods 01b: 5 clock periods 10b: 6 clock periods (default) 11b: 7 clock periods 3:2 RDW[1:0] R,W RD Wait, number of MCU_CLK periods for RD read bus cycle during any MOVX instruction 00b: 4 clock periods 01b: 5 clock periods 10b: 6 clock periods (default) 11b: 7 clock periods 1:0 CW[1:0] R,W Code Wait, number of MCU_CLK periods for PSEN read bus cycle during any code byte fetch or during any MOVC code byte read instruction. Periods will increase with PFQ stall 00b: 3 clock periods - exception, for MOVC instructions this setting results 4 clock periods 01b: 4 clock periods 10b: 5 clock periods 11b: 6 clock periods (default)uPSD33xx 64/231 Table 36. Number of MCU_CLK Periods Required to Optimize Bus Transfer Rate Note: 1. VDD of the PSD Module 2. “Turbo mode PSD” means that the PSD Module is in the faster, Turbo mode (default condition). A PSD Module in Non-Turbo mode is slower, but consumes less current. See PSD Module section, titled “PLD Non-Turbo Mode” for details. MCU Clock Frequency, MCU_CLK (fMCU) CW[1:0] Clk Periods RDW[1:0] Clk Periods WRW[1:0] Clk Periods 3.3V(1) 5V(1) 3.3V(1) 5V(1) 3.3V(1) 5V(1) 40MHz, Turbo mode PSD(2) 545454 40MHz, Non-Turbo mode PSD 6 5 6 5 6 5 36MHz, Turbo mode PSD 545454 36MHz, Non-Turbo mode PSD 6 4 6 4 6 4 32MHz, Turbo mode PSD 545454 32MHz, Non-Turbo mode PSD 5 4 5 4 5 4 28MHz, Turbo mode PSD 434444 28MHz, Non-Turbo mode PSD 5 4 5 4 5 4 24MHz, Turbo mode PSD 434444 24MHz, Non-Turbo mode PSD 4 3 4 4 4 4 20MHz and below, Turbo mode PSD 334444 20MHz and below, Non-Turbo mode PSD 3 3 4 4 4 465/231 uPSD33xx SUPERVISORY FUNCTIONS Supervisory circuitry on the MCU Module will issue an internal reset signal to the MCU Module and simultaneously to the PSD Module as a result of any of the following four events: – The external RESET_IN pin is asserted – The Low Voltage Detect (LVD) circuitry has detected a voltage on VCC below a specific threshold (power-on or voltage sags) – The JTAG Debug interface has issued a reset command – The Watch Dog Timer (WDT) has timed out The resulting internal reset signal, MCU_RESET, will force the 8032 into a known reset state while asserted, and then 8032 program execution will jump to the reset vector at program address 0000h just after MCU_RESET is deasserted. The MCU Module will also assert an active low internal reset signal, RESET, to the PSD Module. If needed, the signal RESET can be driven out to external system components through any PLD output pin on the PSD Module. When driving this “RESET_OUT” signal from a PLD output, the user can choose to make it either active-high or activelow logic, depending on the PLD equation. External Reset Input Pin, RESET_IN The RESET_IN pin can be connected directly to a mechanical reset switch or other device which pulls the signal to ground to invoke a reset. RESET_IN is pulled up internally and enters a Schmitt trigger input buffer with a voltage hysteresis of VRST_HYS for immunity to the effects of slow signal rise and fall times, as shown in Figure 20. RESET_IN is also filtered to reject a voltage spike less than a duration of tRST_FIL. The RESET_IN signal must be maintained at a logic '0' for at least a duration of tRST_LO_IN while the oscillator is running. The resulting MCU_RESET signal will last only as long as the RESET_IN signal is active (it is not stretched). Refer to the Supervisor AC specifications in Table 150., page 221 at the end of this document for these parameter values. Figure 20. Supervisor Reset Generation S Q MCU Clock Sync Noise Filter VCC PIN PULL-UP DELAY, tRST_ACTV R AI09603 RESET_IN RESET to PSD Module MCU_RESET to MCU and Peripherals LVD JTAG Debug WDTuPSD33xx 66/231 Low VCC Voltage Detect, LVD An internal reset is generated by the LVD circuit when VCC drops below the reset threshold, VLV_THRESH. After VCC returns to the reset threshold, the MCU_RESET signal will remain asserted for tRST_ACTV before it is released. The LVD circuit is always enabled (cannot be disabled by SFR), even in Idle Mode and Power-down Mode. The LVD input has a voltage hysteresis of VRST_HYS and will reject voltage spikes less than a duration of tRST_FIL. Important: The LVD voltage threshold is VLV_THRESH, suitable for monitoring both the 3.3V VCC supply on the MCU Module and the 3.3V VDD supply on the PSD Module for 3.3V uPSD33xxV devices, since these supplies are one in the same on the circuit board. However, for 5V uPSD33xx devices, VLV_THRESH is not suitable for monitoring the 5V VDD voltage supply (VLV_THRESH is too low), but good for monitoring the 3.3V VCC supply. In the case of 5V uPSD33xx devices, an external means is required to monitor the separate 5V VDD supply, if desired. Power-up Reset At power up, the internal reset generated by the LVD circuit is latched as a logic '1' in the POR bit of the SFR named PCON (Table 24., page 50). Software can read this bit to determine whether the last MCU reset was the result of a power up (cold reset) or a reset from some other condition (warm reset). This bit must be cleared with software. JTAG Debug Reset The JTAG Debug Unit can generate a reset for debugging purposes. This reset source is also available when the MCU is in Idle Mode and PowerDown Mode (the JTAG debugger can be used to exit these modes). Watchdog Timer, WDT When enabled, the WDT will generate a reset whenever it overflows. Firmware that is behaving correctly will periodically clear the WDT before it overflows. Run-away firmware will not be able to clear the WDT, and a reset will be generated. By default, the WDT is disabled after each reset. Note: The WDT is not active during Idle mode or Power-down Mode. There are two SFRs that control the WDT, they are WDKEY (Table 37., page 68) and WDRST (Table 38., page 68). If WDKEY contains 55h, the WDT is disabled. Any value other than 55h in WDKEY will enable the WDT. By default, after any reset condition, WDKEY is automatically loaded with 55h, disabling the WDT. It is the responsibility of initialization firmware to write some value other than 55h to WDKEY after each reset if the WDT is to be used. The WDT consists of a 24-bit up-counter (Figure 21), whose initial count is 000000h by default after every reset. The most significant byte of this counter is controlled by the SFR, WDRST. After being enabled by WDKEY, the 24-bit count is increased by 1 for each MCU machine cycle. When the count overflows beyond FFFFFh (224 MCU machine cycles), a reset is issued and the WDT is automatically disabled (WDKEY = 55h again). To prevent the WDT from timing out and generating a reset, firmware must repeatedly write some value to WDRST before the count reaches FFFFFh. Whenever WDRST is written, the upper 8 bits of the 24-bit counter are loaded with the written value, and the lower 16 bits of the counter are cleared to 0000h. The WDT time-out period can be adjusted by writing a value other that 00h to WDRST. For example, if WDRST is written with 04h, then the WDT will start counting 040000h, 040001h, 040002h, and so on for each MCU machine cycle. In this example, the WDT time-out period is shorter than if WDRST was written with 00h, because the WDT is an up-counter. A value for WDRST should never be written that results in a WDT time-out period shorter than the time required to complete the longest code task in the application, else unwanted WDT overflows will occur. Figure 21. Watchdog Counter 23 15 7 0 8-bits 8-bits 8-bits SFR, WDRST AI0960467/231 uPSD33xx The formula to determine WDT time-out period is: WDTPERIOD = tMACH_CYC x NOVERFLOW NOVERFLOW is the number of WDT up-counts required to reach FFFFFFh. This is determined by the value written to the SFR, WDRST. tMACH_CYC is the average duration of one MCU machine cycle. By default, an MCU machine cycle is always 4 MCU_CLK periods for uPSD33xx, but the following factors can sometimes add more MCU_CLK periods per machine cycle: – The number of MCU_CLK periods assigned to MCU memory bus cycles as determined in the SFR, BUSCON. If this setting is greater than 4, then machine cycles have additional MCU_CLK periods during memory transfers. – Whether or not the PFQ/BC circuitry issues a stall during a particular MCU machine cycle. A stall adds more MCU_CLK periods to a machine cycle until the stall is removed. tMACH_CYC is also affected by the absolute time of a single MCU_CLK period. This number is fixed by the following factors: – Frequency of the external crystal, resonator, or oscillator: (fOSC) – Bit settings in the SFR CCON0, which can divide fOSC and change MCU_CLK As an example, assume the following: 1. fOSC is 40MHz, thus its period is 25ns. 2. CCON0 is 10h, meaning no clock division, so the period of MCU_CLK is also 25ns. 3. BUSCON is C1h, meaning the PFQ and BC are enabled, and each MCU memory bus cycle is 4 MCU_CLK periods, adding no additional MCU_CLK periods to MCU machine cycles during memory transfers. 4. Assume there are no stalls from the PFQ/BC. In reality, there are occational stalls but their occurance has minimal impact on WDT timeout period. 5. WDRST contains 00h, meaning a full 224 upcounts are required to reach FFFFFh and generate a reset. In this example, tMACH_CYC = 100ns (4 MCU_CLK periods x 25ns) NOVERFLOW = 224 = 16777216 up-counts WDTPERIOD = 100ns X 16777216 = 1.67 seconds The actual value will be slightly longer due to PFQ/ BC. Firmware Example: The following 8051 assembly code illustrates how to operate the WDT. A simple statement in the reset initialization firmware enables the WDT, and then a periodic write to clear the WDT in the main firmware is required to keep the WDT from overflowing. This firmware is based on the example above (40MHz fOSC, CCON0 = 10h, BUSCON = C1h). For example, in the reset initialization firmware (the function that executes after a jump to the reset vector): Somewhere in the flow of the main program, this statement will execute periodically to reset the WDT before it’s time-out period of 1.67 seconds. For example: MOV AE, #AA ; enable WDT by writing value to ; WDKEY other than 55h MOV A6, #00 ; reset WDT, loading 000000h. ; Counting will automatically ; resume as long as 55h in not in ; WDKEYuPSD33xx 68/231 Table 37. WDKEY: Watchdog Timer Key Register (SFR AEh, reset value 55h) Table 38. WDRST: Watchdog Timer Reset Counter Register (SFR A6h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 WDKEY[7:0] Details Bit Symbol R/W Definition [7:0] WDKEY W 55h disables the WDT from counting. 55h is automatically loaded in this SFR after any reset condition, leaving the WDT disabled by default. Any value other than 55h written to this SFR will enable the WDT, and counting begins. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 WDRST[7:0] Details Bit Symbol R/W Definition [7:0] WDRST W This SFR is the upper byte of the 24-bit WDT up-counter. Writing this SFR sets the upper byte of the counter to the written value, and clears the lower two bytes of the counter to 0000h. Counting begins when WDKEY does not contain 55h.69/231 uPSD33xx STANDARD 8032 TIMER/COUNTERS There are three 8032-style 16-bit Timer/Counter registers (Timer 0, Timer 1, Timer 2) that can be configured to operate as timers or event counters. There are two additional 16-bit Timer/Counters in the Programmable Counter Array (PCA), seePCA Block, page 123 for details. Standard Timer SFRs Timer 0 and Timer 1 have very similar functions, and they share two SFRs for control: ■ TCON (Table 39., page 70) ■ TMOD (Table 40., page 72). Timer 0 has two SFRs that form the 16-bit counter, or that can hold reload values, or that can scale the clock depending on the timer/counter mode: ■ TH0 is the high byte, address 8Ch ■ TL0 is the low byte, address 8Ah Timer 1 has two similar SFRs: ■ TH1 is the high byte, address 8Dh ■ TL1 is the low byte, address 8Bh Timer 2 has one control SFR: ■ T2CON (Table 41., page 75) Timer 2 has two SFRs that form the 16-bit counter, and perform other functions: ■ TH2 is the high byte, address CDh ■ TL2 is the low byte, address CCh Timer 2 has two SFRs for capture and reload: ■ RCAP2H is the high byte, address CBh ■ RCAP2L is the low byte, address CAh Clock Sources When enabled in the “Timer” function, the Registers THx and TLx are incremented every 1/12 of the oscillator frequency (fOSC). This timer clock source is not effected by MCU clock dividers in the CCON0, stalls from PFQ/BC, or bus transfer cycles. Timers are always clocked at 1/12 of fOSC. When enabled in the “Counter” function, the Registers THx and TLx are incremented in response to a 1-to-0 transition sampled at their corresponding external input pin: pin C0 for Timer 0; pin C1 for Timer 1; or pin T2 for Timer 2. In this function, the external clock input pin is sampled by the counter at a rate of 1/12 of fOSC. When a logic '1' is determined in one sample, and a logic '0' in the next sample period, the count is incremented at the very next sample period (period1: sample=1, period2: sample=0, period3: increment count while continuing to sample). This means the maximum count rate is 1/24 of the fOSC. There are no restrictions on the duty cycle of the external input signal, but to ensure that a given level is sampled at least once before it changes, it should be active for at least one full sample period (12 / fOSC, seconds). However, if MCU_CLK is divided by the SFR CCON0, then the sample period must be calculated based on the resultant, longer, MCU_CLK frequency. In this case, an external clock signal on pins C0, C1, or T2 should have a duration longer than one MCU machine cycle, tMACH_CYC. The section, Watchdog Timer, WDT, page 66 explains how to estimate tMACH_CYC.uPSD33xx 70/231 Table 39. TCON: Timer Control Register (SFR 88h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Details Bit Symbol R/W Definition 7 TF1 R Timer 1 overflow interrupt flag. Set by hardware upon overflow. Automatically cleared by hardware after firmware services the interrupt for Timer 1. 6 TR1 R,W Timer 1 run control. 1 = Timer/Counter 1 is on, 0 = Timer/Counter 1 is off. 5 TF0 R Timer 0 overflow interrupt flag. Set by hardware upon overflow. Automatically cleared by hardware after firmware services the interrupt for Timer 0. 4 TR0 R,W Timer 0 run control. 1 = Timer/Counter 0 is on, 0 = Timer/Counter 0 is off. 3 IE1 R Interrupt flag for external interrupt pin, EXTINT1. Set by hardware when edge is detected on pin. Automatically cleared by hardware after firmware services EXTINT1 interrupt. 2 IT1 R,W Trigger type for external interrupt pin EXTINT1. 1 = falling edge, 0 = lowlevel 1 IE0 R Interrupt flag for external interrupt pin, EXTINT0. Set by hardware when edge is detected on pin. Automatically cleared by hardware after firmware services EXTINT0 interrupt. 0 IT0 R,W Trigger type for external interrupt pin EXTINT0. 1 = falling edge, 0 = lowlevel71/231 uPSD33xx SFR, TCON Timer 0 and Timer 1 share the SFR, TCON, that controls these timers and provides information about them. See Table 39., page 70. Bits IE0 and IE1 are not related to Timer/Counter functions, but they are set by hardware when a signal is active on one of the two external interrupt pins, EXTINT0 and EXTINT1. For system information on all of these interrupts, see Table 16., page 41, Interrupt Summary. Bits IT0 and IT1 are not related to Timer/Counter functions, but they control whether or not the two external interrupt input pins, EXTINT0 and EXTINT1 are edge or level triggered. SFR, TMOD Timer 0 and Timer 1 have four modes of operation controlled by the SFR named TMOD (Table 40). Timer 0 and Timer 1 Operating Modes The “Timer” or “Counter” function is selected by the C/T control bits in TMOD. The four operating modes are selected by bit-pairs M[1:0] in TMOD. Modes 0, 1, and 2 are the same for both Timer/ Counters. Mode 3 is different. Mode 0. Putting either Timer/Counter into Mode 0 makes it an 8-bit Counter with a divide-by-32 prescaler. Figure 22 shows Mode 0 operation as it applies to Timer 1 (same applies to Timer 0). In this mode, the Timer Register is configured as a 13-bit register. As the count rolls over from all '1s' to all '0s,' it sets the Timer Interrupt flag TF1. The counted input is enabled to the Timer when TR1 = 1 and either GATE = 0 or EXTINT1 = 1. (Setting GATE = 1 allows the Timer to be controlled by external input pin, EXTINT1, to facilitate pulse width measurements). TR1 is a control bit in the SFR, TCON. GATE is a bit in the SFR, TMOD. The 13-bit register consists of all 8 bits of TH1 and the lower 5 bits of TL1. The upper 3 bits of TL1 are indeterminate and should be ignored. Setting the run flag, TR1, does not clear the registers. Mode 0 operation is the same for the Timer 0 as for Timer 1. Substitute TR0, TF0, C0, TL0, TH0, and EXTINT0 for the corresponding Timer 1 signals in Figure 22. There are two different GATE Bits, one for Timer 1 and one for Timer 0. Mode 1. Mode 1 is the same as Mode 0, except that the Timer Register is being run with all 16 bits. Mode 2. Mode 2 configures the Timer Register as an 8-bit Counter (TL1) with automatic reload, as shown in Figure 23., page 73. Overflow from TL1 not only sets TF1, but also reloads TL1 with the contents of TH1, which is preset with firmware. The reload leaves TH1 unchanged. Mode 2 operation is the same for Timer/Counter 0. Mode 3. Timer 1 in Mode 3 simply holds its count. The effect is the same as setting TR1 = 0. Timer 0 in Mode 3 establishes TL0 and TH0 as two separate counters. The logic for Mode 3 on Timer 0 is shown in Figure 24., page 73. TL0 uses the Timer 0 control Bits: C/T, GATE, TR0, and TF0, as well as the pin EXTINT0. TH0 is locked into a timer function (counting at a rate of 1/12 fOSC) and takes over the use of TR1 and TF1 from Timer 1. Thus, TH0 now controls the “Timer 1“ interrupt flag. Mode 3 is provided for applications requiring an extra 8-bit timer on the counter (see Figure 24., page 73). With Timer 0 in Mode 3, a uPSD33xx device can look like it has three Timer/ Counters (not including the PCA). When Timer 0 is in Mode 3, Timer 1 can be turned on and off by switching it out of and into its own Mode 3, or can still be used by the serial port as a baud rate generator, or in fact, in any application not requiring an interrupt.uPSD33xx 72/231 Table 40. TMOD: Timer Mode Register (SFR 89h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 GATE C/T M[1:0] GATE C/T M[1:0] Details Bit Symbol R/W Timer Definition (T/C is abbreviation for Timer/Counter) 7 GATE R,W Timer 1 Gate control. When GATE = 1, T/C is enabled only while pin EXTINT1 is '1' and the flag TR1 is '1.' When GATE = 0, T/C is enabled whenever the flag TR1 is '1.' 6 C/T R,W Counter or Timer function select. When C/T = 0, function is timer, clocked by internal clock. C/T = 1, function is counter, clocked by signal sampled on external pin, C1. [5:4] M[1:0] R,W Mode Select. 00b = 13-bit T/C. 8 bits in TH1 with TL1 as 5-bit prescaler. 01b = 16-bit T/C. TH1 and TL1 are cascaded. No prescaler. 10b = 8-bit auto-reload T/C. TH1 holds a constant and loads into TL1 upon overflow. 11b = Timer Counter 1 is stopped. 3 GATE R,W Timer 0 Gate control. When GATE = 1, T/C is enabled only while pin EXTINT0 is '1' and the flag TR0 is '1.' When GATE = 0, T/C is enabled whenever the flag TR0 is '1.' 2 C/T R,W Counter or Timer function select. When C/T = 0, function is timer, clocked by internal clock. C/T = 1, function is counter, clocked by signal sampled on external pin, C0. [1:0] M[1:0] R,W Mode Select. 00b = 13-bit T/C. 8 bits in TH0 with TL0 as 5-bit prescaler. 01b = 16-bit T/C. TH0 and TL0 are cascaded. No prescaler. 10b = 8-bit auto-reload T/C. TH0 holds a constant and loads into TL0 upon overflow. 11b = TL0 is 8-bit T/C controlled by standard Timer 0 control bits. TH0 is a separate 8-bit timer that uses Timer 1 control bits.73/231 uPSD33xx Figure 22. Timer/Counter Mode 0: 13-bit Counter Figure 23. Timer/Counter Mode 2: 8-bit Auto-reload Figure 24. Timer/Counter Mode 3: Two 8-bit Counters AI06622 f OSC TF1 Interrupt Gate TR1 EXTINT1 pin C1 pin Control TL1 (5 bits) TH1 (8 bits) C/T = 0 C/T = 1 ÷ 12 AI06623 f OSC TF1 Interrupt Gate TR1 EXTINT1 pin C1 pin Control TL1 (8 bits) TH1 (8 bits) C/T = 0 C/T = 1 ÷ 12 AI06624 f OSC TF0 Interrupt Gate TR0 EXTINT0 pin C0 pin Control TL0 (8 bits) C/T = 0 C/T = 1 ÷ 12 f OSC TF1 Interrupt Control TH0 (8 bits) ÷ 12 TR1uPSD33xx 74/231 Timer 2 Timer 2 can operate as either an event timer or as an event counter. This is selected by the bit C/T2 in the SFR named, T2CON (Table 41., page 75). Timer 2 has three operating modes selected by bits in T2CON, according to Table 42., page 76. The three modes are: ■ Capture mode ■ Auto re-load mode ■ Baud rate generator mode Capture Mode. In Capture Mode there are two options which are selected by the bit EXEN2 in T2CON. Figure 25., page 79 illustrates Capture mode. If EXEN2 = 0, then Timer 2 is a 16-bit timer if C/T2 = 0, or it’s a 16-bit counter if C/T2 = 1, either of which sets the interrupt flag bit TF2 upon overflow. If EXEN2 = 1, then Timer 2 still does the above, but with the added feature that a 1-to-0 transition at external input pin T2X causes the current value in the Timer 2 registers, TL2 and TH2, to be captured into Registers RCAP2L and RCAP2H, respectively. In addition, the transition at T2X causes interrupt flag bit EXF2 in T2CON to be set. Either flag TF2 or EXF2 will generate an interrupt and the MCU must read both flags to determine the cause. Flags TF2 and EXF2 are not automatically cleared by hardware, so the firmware servicing the interrupt must clear the flag(s) upon exit of the interrupt service routine. Auto-reload Mode. In the Auto-reload Mode, there are again two options, which are selected by the bit EXEN2 in T2CON. Figure 26., page 79 shows Auto-reload mode. If EXEN2 = 0, then when Timer 2 counts up and rolls over from FFFFh it not only sets the interrupt flag TF2, but also causes the Timer 2 registers to be reloaded with the 16-bit value contained in Registers RCAP2L and RCAP2H, which are preset with firmware. If EXEN2 = 1, then Timer 2 still does the above, but with the added feature that a 1-to-0 transition at external input T2X will also trigger the 16-bit reload and set the interrupt flag EXF2. Again, firmware servicing the interrupt must read both TF2 and EXF2 to determine the cause, and clear the flag(s) upon exit. Note: The uPSD33xx does not support selectable up/down counting in Auto-reload mode (this feature was an extension to the original 8032 architecture).75/231 uPSD33xx Table 41. T2CON: Timer 2 Control Register (SFR C8h, reset value 00h) Note: 1. The RCLK1 and TCLK1 Bits in the SFR named PCON control UART1, and have the exact same function as RCLK and TCLK. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2 CP/RL2 Details Bit Symbol R/W Definition 7 TF2 R,W Timer 2 flag, causes interrupt if enabled. TF2 is set by hardware upon overflow. Must be cleared by firmware. TF2 will not be set when either RCLK or TCLK =1. 6 EXF2 R,W Timer 2 flag, causes interrupt if enabled. EXF2 is set when a capture or reload is caused by a negative transition on T2X pin and EXEN2 = 1. EXF2 must be cleared by firmware. 5 RCLK(1) R,W UART0 Receive Clock control. When RCLK = 1, UART0 uses Timer 2 overflow pulses for its receive clock in Modes 1 and 3. RCLK=0, Timer 1 overflow is used for its receive clock 4 TCLK(1) R,W UART0 Transmit Clock control. When TCLK = 1, UART0 uses Timer 2 overflow pulses for its transmit clock in Modes 1 and 3. TCLK=0, Timer 1 overflow is used for transmit clock 3 EXEN2 R,W Timer 2 External Enable. When EXEN2 = 1, capture or reload results when negative edge on pin T2X occurs. EXEN2 = 0 causes Timer 2 to ignore events at pin T2X. 2 TR2 R,W Timer 2 run control. 1 = Timer/Counter 2 is on, 0 = Timer Counter 2 is off. 1 C/T2 R,W Counter or Timer function select. When C/T2 = 0, function is timer, clocked by internal clock. When C/T2 = 1, function is counter, clocked by signal sampled on external pin, T2. 0 CP/RL2 R,W Capture/Reload. When CP/RL2 = 1, capture occurs on negative transition at pin T2X if EXEN2 = 1. When CP/RL2 = 0, auto-reload occurs when Timer 2 overflows, or on negative transition at pin T2X when EXEN2=1. When RCLK = 1 or TCLK = 1, CP/RL2 is ignored, and Timer 2 is forced to autoreload upon Timer 2 overflowuPSD33xx 76/231 Table 42. Timer/Counter 2 Operating Modes Note: ↓ = falling edge Mode Bits in T2CON SFR Pin T2X Remarks Input Clock RCLK or TCLK CP/ RL2 TR2 EXEN2 Timer, Internal Counter, External (Pin T2, P1.0) 16-bit Autoreload 001 0 x reload [RCAP2H, RCAP2L] to [TH2, TL2] upon overflow (up counting) fOSC/12 MAX fOSC/24 001 1 ↓ reload [RCAP2H, RCAP2L] to [TH2, TL2] at falling edge on pin T2X 16-bit Capture 0 1 1 0 x 16-bit Timer/Counter (up counting) fOSC/12 MAX fOSC/24 011 1 ↓ Capture [TH2, TL2] and store to [RCAP2H, RCAP2L] at falling edge on pin T2X Baud Rate Generator 1 x 1 0 x No overflow interrupt request (TF2) fOSC/2 – 1x1 1 ↓ Extra Interrupt on pin T2X, sets TF2 Off x x 0 x x Timer 2 stops – –77/231 uPSD33xx Baud Rate Generator Mode. The RCLK and/or TCLK Bits in the SFR T2CON allow the transmit and receive baud rates on serial port UART0 to be derived from either Timer 1 or Timer 2. Figure 27., page 80 illustrates Baud Rate Generator Mode. When TCLK = 0, Timer 1 is used as UART0’s transmit baud generator. When TCLK = 1, Timer 2 will be the transmit baud generator. RCLK has the same effect for UART0’s receive baud rate. With these two bits, UART0 can have different receive and transmit baud rates - one generated by Timer 1, the other by Timer 2. Note: Bits RCLK1 and TCLK1 in the SFR named PCON (see PCON: Power Control Register (SFR 87h, reset value 00h), page 50) have identical functions as RCLK and TCLK but they apply to UART1 instead. For simplicity in the following discussions about baud rate generation, no suffix will be used when referring to SFR registers and bits related to UART0 or UART1, since each UART interface has identical operation. Example, TCLK or TCLK1 will be referred to as just TCLK. The Baud Rate Generator Mode is similar to the Auto-reload Mode, in that a roll over in TH2 causes the Timer 2 registers, TH2 and TL2, to be reloaded with the 16-bit value in Registers RCAP2H and RCAP2L, which are preset with firmware. The baud rates in UART Modes 1 and 3 are determined by Timer 2’s overflow rate as follows: UART Mode 1,3 Baud Rate = Timer 2 Overflow Rate / 16 The timer can be configured for either “timer” or “counter” operation. In the most typical applications, it is configured for “timer” operation (C/T2 = 0). “Timer” operation is a little different for Timer 2 when it's being used as a baud rate generator. In this case, the baud rate is given by the formula: UART Mode 1,3 Baud Rate = fOSC/(32 x [65536 – [RCAP2H, RCAP2L])) where [RCAP2H, RCAP2L] is the content of the SFRs RCAP2H and RCAP2L taken as a 16-bit unsigned integer. A roll-over in TH2 does not set TF2, and will not generate an interrupt. Therefore, the Timer Interrupt does not have to be disabled when Timer 2 is in the Baud Rate Generator Mode. If EXEN2 is set, a 1-to-0 transition on pin T2X will set the Timer 2 interrupt flag EXF2, but will not cause a reload from RCAP2H and RCAP2L to TH2 and TL2. Thus when Timer 2 is in use as a baud rate generator, the pin T2X can be used as an extra external interrupt, if desired. When Timer 2 is running (TR2 = 1) in a “timer” function in the Baud Rate Generator Mode, firmware should not read or write TH2 or TL2. Under these conditions the results of a read or write may not be accurate. However, SFRs RCAP2H and RCAP2L may be read, but should not be written, because a write might overlap a reload and cause write and/or reload errors. Timer 2 should be turned off (clear TR2) before accessing Timer 2 or Registers RCAP2H and RCAP2L, in this case. Table 43., page 78 shows commonly used baud rates and how they can be obtained from Timer 2, with T2CON = 34h.uPSD33xx 78/231 Table 43. Commonly Used Baud Rates Generated from Timer2 (T2CON = 34h) fOSC MHz Desired Baud Rate Timer 2 SFRs Resulting Baud Rate Baud Rate Deviation RCAP2H (hex) RCAP2L(hex) 40.0 115200 FF F5 113636 -1.36% 40.0 57600 FF EA 56818 -1.36% 40.0 28800 FF D5 29070 0.94% 40.0 19200 FF BF 19231 0.16% 40.0 9600 FF 7E 9615 0.16% 36.864 115200 FF F6 115200 0 36.864 57600 FF EC 57600 0 36.864 28800 FF D8 28800 0 36.864 19200 FF C4 19200 0 36.864 9600 FF 88 9600 0 36.0 28800 FF D9 28846 0.16% 36.0 19200 FF C5 19067 -0.69% 36.0 9600 FF 8B 9615 0.16% 24.0 57600 FF F3 57692 0.16% 24.0 28800 FF E6 28846 0.16% 24.0 19200 FF D9 19231 0.16% 24.0 9600 FF B2 9615 0.16% 12.0 28800 FF F3 28846 0.16% 12.0 9600 FF D9 9615 0.16% 11.0592 115200 FF FD 115200 0 11.0592 57600 FF FA 57600 0 11.0592 28800 FF F4 28800 0 11.0592 19200 FF EE 19200 0 11.0592 9600 FF DC 9600 0 3.6864 115200 FF FF 115200 0 3.6864 57600 FF FE 57600 0 3.6864 28800 FF FC 28800 0 3.6864 19200 FF FA 19200 0 3.6864 9600 FF F4 9600 0 1.8432 19200 FF FD 19200 0 1.8432 9600 FF FA 9600 079/231 uPSD33xx Figure 25. Timer 2 in Capture Mode Figure 26. Timer 2 in Auto-Reload Mode AI06625 f OSC TF2 Capture TR2 T2 pin Control TL2 (8 bits) TH2 (8 bits) C/T2 = 0 C/T2 = 1 ÷ 12 EXP2 Control EXEN2 RCAP2L RCAP2H T2X pin Timer 2 Interrupt Transition Detector AI06626 f OSC TF2 Reload TR2 T2 pin Control TL2 (8 bits) TH2 (8 bits) C/T2 = 0 C/T2 = 1 ÷ 12 EXP2 Control EXEN2 RCAP2L RCAP2H T2X pin Timer 2 Interrupt Transition DetectoruPSD33xx 80/231 Figure 27. Timer 2 in Baud Rate Generator Mode AI09605 f OSC Reload TR2 T2 pin Control Note: Oscillator frequency is divided by 2, not 12 like in other timer modes. Note: Availability of additional external interrupt. TL2 (8 bits) TH2 (8 bits) C/T2 = 0 C/T2 = 1 ÷ 12 ÷ 2 ÷ 16 ÷ 16 EXF2 Control EXEN2 RCAP2L RCAP2H T2X pin Timer 2 Interrupt TX CLK RX CLK Timer 1 Overflow SMOD RCLK '1' '0' '0' '1' '1' '0' TCLK Transition Detector81/231 uPSD33xx SERIAL UART INTERFACES uPSD33xx devices provide two standard 8032 UART serial ports. – The first port, UART0, is connected to pins RxD0 (P3.0) and TxD0 (P3.1) – The second port, UART1 is connected to pins RxD1 (P1.2) and TxD1 (P1.3). UART1 can optionally be routed to pins P4.2 and P4.3 as described in Alternate Functions, page 59. The operation of the two serial ports are the same and are controlled by two SFRs: ■ SCON0 (Table 45., page 82) for UART0 ■ SCON1 (Table 46., page 83) for UART1 Each UART has its own data buffer accessed through an SFR listed below: ■ SBUF0 for UART0, address 99h ■ SBUF1 for UART1, address D9h When writing SBU0 or SBUF1, the data automatically loads into the associated UART transmit data register. When reading this SFR, data comes from a different physical register, which is the receive register of the associated UART. Note: For simplicity in the remaining UART discussions, the suffix “0” or “1” will be dropped when referring to SFR registers and bits related to UART0 or UART1, since each UART interface has identical operation. Example, SBUF0 and SBUF1 will be referred to as just SBUF. Each UART serial port can be full-duplex, meaning it can transmit and receive simultaneously. Each UART is also receive-buffered, meaning it can commence reception of a second byte before a previously received byte has been read from the SBUF Register. However, if the first byte still has not been read by the time reception of the second byte is complete, one of the bytes will be lost. UART Operation Modes Each UART can operate in one of four modes, one mode is synchronous, and the others are asynchronous as shown in Table 44. Mode 0. Mode 0 provides asynchronous, half-duplex operation. Serial data is both transmitted, and received on the RxD pin. The TxD pin outputs a shift clock for both transmit and receive directions, thus the MCU must be the master. Eight bits are transmitted/received LSB first. The baud rate is fixed at 1/12 of fOSC. Mode 1. Mode 1 provides standard asynchronous, full-duplex communication using a total of 10 bits per data byte. Data is transmitted through TxD and received through RxD with: a Start Bit (logic '0'), eight data bits (LSB first), and a Stop Bit (logic '1'). Upon receive, the eight data bits go into the SFR SBUF, and the Stop Bit goes into bit RB8 of the SFR SCON. The baud rate is variable and derived from overflows of Timer 1 or Timer 2. Mode 2. Mode 2 provides asynchronous, full-duplex communication using a total of 11 bits per data byte. Data is transmitted through TxD and received through RxD with: a Start Bit (logic '0'); eight data bits (LSB first); a programmable 9th data bit; and a Stop Bit (logic '1'). Upon Transmit, the 9th data bit (from bit TB8 in SCON) can be assigned the value of '0' or '1.' Or, for example, the Parity Bit (P, in the PSW) could be moved into TB8. Upon receive, the 9th data bit goes into RB8 in SCON, while the Stop Bit is ignored. The baud rate is programmable to either 1/32 or 1/64 of fOSC. Mode 3. Mode 3 is the same as Mode 2 in all respects except the baud rate is variable like it is in Mode 1. In all four modes, transmission is initiated by any instruction that uses SBUF as a destination register. Reception is initiated in Mode 0 by the condition RI = 0 and REN = 1. Reception is initiated in the other modes by the incoming Start Bit if REN = 1. Table 44. UART Operating Modes Mode Synchronization Bits of SFR, SCON Baud Clock Data Bits Start/Stop Bits See Figure SM0 SM1 0 Synchronous 0 0 fOSC/12 8 None Figure 28., page 86 1 Asynchronous 0 1 Timer 1 or Timer 2 Overflow 8 1 Start, 1 Stop Figure 30., page 88 2 Asynchronous 1 0 fOSC/32 or fOSC/64 9 1 Start, 1 Stop Figure 32., page 90 3 Asynchronous 1 1 Timer 1 or Timer 2 Overflow 9 1 Start, 1 Stop Figure 34., page 91uPSD33xx 82/231 Multiprocessor Communications. Modes 2 and 3 have a special provision for multiprocessor communications. In these modes, 9 data bits are received. The 9th one goes into bit RB8, then comes a stop bit. The port can be programmed such that when the stop bit is received, the UART interrupt will be activated only if bit RB8 = 1. This feature is enabled by setting bit SM2 in SCON. A way to use this feature in multi-processor systems is as follows: When the master processor wants to transmit a block of data to one of several slaves, it first sends out an address byte which identifies the target slave. An address byte differs from a data byte in that the 9th bit is 1 in an address byte and 0 in a data byte. With SM2 = 1, no slave will be interrupted by a data byte. An address byte, however, will interrupt all slaves, so that each slave can examine the received byte and see if it is being addressed. The addressed slave will clear its SM2 bit and prepare to receive the data bytes that will be coming. The slaves that were not being addressed leave their SM2 bits set and go on about their business, ignoring the coming data bytes. SM2 has no effect in Mode 0, and in Mode 1, SM2 can be used to check the validity of the stop bit. In a Mode 1 reception, if SM2 = 1, the receive interrupt will not be activated unless a valid stop bit is received. Serial Port Control Registers The SFR SCON0 controls UART0, and SCON1 controls UART1, shown in Table 45 and Table 46. These registers contain not only the mode selection bits, but also the 9th data bit for transmit and receive (bits TB8 and RB8), and the UART Interrupt flags, TI and RI. Table 45. SCON0: Serial Port UART0 Control Register (SFR 98h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SM0 SM1 SM2 REN TB8 RB8 TI RI Details Bit Symbol R/W Definition 7 SM0 R,W Serial Mode Select, See Table 44., page 81. Important, notice bit order of SM0 and SM1. [SM0:SM1] = 00b, Mode 0 [SM0:SM1] = 01b, Mode 1 [SM0:SM1] = 10b, Mode 2 [SM0:SM1] = 11b, Mode 3 6 SM1 R,W 5 SM2 R,W Serial Multiprocessor Communication Enable. Mode 0: SM2 has no effect but should remain 0. Mode 1: If SM2 = 0 then stop bit ignored. SM2 =1 then RI active if stop bit = 1. Mode 2 and 3: Multiprocessor Comm Enable. If SM2=0, 9th bit is ignored. If SM2=1, RI active when 9th bit = 1. 4 REN R,W Receive Enable. If REN=0, UART reception disabled. If REN=1, reception is enabled 3 TB8 R,W TB8 is assigned to the 9th transmission bit in Mode 2 and 3. Not used in Mode 0 and 1. 2 RB8 R,W Mode 0: RB8 is not used. Mode 1: If SM2 = 0, the RB8 is the level of the received stop bit. Mode 2 and 3: RB8 is the 9th data bit that was received in Mode 2 and 3. 1 TI R,W Transmit Interrupt flag. Causes interrupt at end of 8th bit time when transmitting in Mode 0, or at beginning of stop bit transmission in other modes. Must clear flag with firmware. 0 RI R,W Receive Interrupt flag. Causes interrupt at end of 8th bit time when receiving in Mode 0, or halfway through stop bit reception in other modes (see SM2 for exception). Must clear this flag with firmware.83/231 uPSD33xx Table 46. SCON1: Serial Port UART1 Control Register (SFR D8h, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SM0 SM1 SM2 REN TB8 RB8 TI RI Details Bit Symbol R/W Definition 7 SM0 R,W Serial Mode Select, See Table 44., page 81. Important, notice bit order of SM0 and SM1. [SM0:SM1] = 00b, Mode 0 [SM0:SM1] = 01b, Mode 1 [SM0:SM1] = 10b, Mode 2 [SM0:SM1] = 11b, Mode 3 6 SM1 R,W 5 SM2 R,W Serial Multiprocessor Communication Enable. Mode 0: SM2 has no effect but should remain 0. Mode 1: If SM2 = 0 then stop bit ignored. SM2 =1 then RI active if stop bit = 1. Mode 2 and 3: Multiprocessor Comm Enable. If SM2=0, 9th bit is ignored. If SM2=1, RI active when 9th bit = 1. 4 REN R,W Receive Enable. If REN=0, UART reception disabled. If REN=1, reception is enabled 3 TB8 R,W TB8 is assigned to the 9th transmission bit in Mode 2 and 3. Not used in Mode 0 and 1. 2 RB8 R,W Mode 0: RB8 is not used. Mode 1: If SM2 = 0, the RB8 is the level of the received stop bit. Mode 2 and 3: RB8 is the 9th data bit that was received in Mode 2 and 3. 1 TI R,W Transmit Interrupt flag. Causes interrupt at end of 8th bit time when transmitting in Mode 0, or at beginning of stop bit transmission in other modes. Must clear flag with firmware. 0 RI R,W Receive Interrupt flag. Causes interrupt at end of 8th bit time when receiving in Mode 0, or halfway through stop bit reception in other modes (see SM2 for exception). Must clear this flag with firmware.uPSD33xx 84/231 UART Baud Rates The baud rate in Mode 0 is fixed: Mode 0 Baud Rate = fOSC / 12 The baud rate in Mode 2 depends on the value of the bit SMOD in the SFR named PCON. If SMOD = 0 (default value), the baud rate is 1/64 the oscillator frequency, fOSC. If SMOD = 1, the baud rate is 1/32 the oscillator frequency. Mode 2 Baud Rate = (2SMOD / 64) x fOSC Baud rates in Modes 1 and 3 are determined by the Timer 1 or Timer 2 overflow rate. Using Timer 1 to Generate Baud Rates. When Timer 1 is used as the baud rate generator (bits RCLK = 0, TCLK = 0), the baud rates in Modes 1 and 3 are determined by the Timer 1 overflow rate and the value of SMOD as follows: Mode 1,3 Baud Rate = (2SMOD / 32) x (Timer 1 overflow rate) The Timer 1 Interrupt should be disabled in this application. The Timer itself can be configured for either “timer” or “counter” operation, and in any of its 3 running modes. In the most typical applications, it is configured for “timer” operation, in the Auto-reload Mode (high nibble of the SFR TMOD = 0010B). In that case the baud rate is given by the formula: Mode 1,3 Baud Rate = (2SMOD / 32) x (fOSC / (12 x [256 – (TH1)])) Table 47 lists various commonly used baud rates and how they can be obtained from Timer 1. Using Timer/Counter 2 to Generate Baud Rates. See Baud Rate Generator Mode, page 77. Table 47. Commonly Used Baud Rates Generated from Timer 1 UART Mode fOSC MHz Desired Baud Rate Resultant Baud Rate Baud Rate Deviation SMOD bit in PCON Timer 1 C/T Bit in TMOD Timer Mode in TMOD TH1 Reload value (hex) Mode 0 Max 40.0 3.33MHz 3.33MHz 0 X X X X Mode 2 Max 40.0 1250 k 1250 k 0 1 X X X Mode 2 Max 40.0 625 k 625 k 0 0 X X X Modes 1 or 3 40.0 19200 18939 -1.36% 1 0 2 F5 Modes 1 or 3 40.0 9600 9470 -1.36% 1 0 2 EA Modes 1 or 3 36.0 19200 18570 -2.34% 1 0 2 F6 Modes 1 or 3 33.333 57600 57870 0.47% 1 0 2 FD Modes 1 or 3 33.333 28800 28934 0.47% 1 0 2 FA Modes 1 or 3 33.333 19200 19290 0.47% 1 0 2 F7 Modes 1 or 3 33.333 9600 9645 0.47% 1 0 2 EE Modes 1 or 3 24.0 9600 9615 0.16% 1 0 2 F3 Modes 1 or 3 12.0 4800 4808 0.16% 1 0 2 F3 Modes 1 or 3 11.0592 57600 57600 0 1 0 2 FF Modes 1 or 3 11.0592 28800 28800 0 1 0 2 FE Modes 1 or 3 11.0592 19200 19200 0 1 0 2 FD Modes 1 or 3 11.0592 9600 9600 0 1 0 2 FA Modes 1 or 3 3.6864 19200 19200 0 1 0 2 FF Modes 1 or 3 3.6864 9600 9600 0 1 0 2 FE Modes 1 or 3 1.8432 9600 9600 0 1 0 2 FF Modes 1 or 3 1.8432 4800 4800 0 1 0 2 FE85/231 uPSD33xx More About UART Mode 0 Refer to the block diagram in Figure 28., page 86, and timing diagram in Figure 29., page 86. Transmission is initiated by any instruction which writes to the SFR named SBUF. At the end of a write operation to SBUF, a 1 is loaded into the 9th position of the transmit shift register and tells the TX Control unit to begin a transmission. Transmission begins on the following MCU machine cycle, when the “SEND” signal is active in Figure 29. SEND enables the output of the shift register to the alternate function on the port containing pin RxD, and also enables the SHIFT CLOCK signal to the alternate function on the port containing the pin, TxD. At the end of each SHIFT CLOCK in which SEND is active, the contents of the transmit shift register are shifted to the right one position. As data bits shift out to the right, zeros come in from the left. When the MSB of the data byte is at the output position of the shift register, then the '1' that was initially loaded into the 9th position, is just to the left of the MSB, and all positions to the left of that contain zeros. This condition flags the TX Control unit to do one last shift, then deactivate SEND, and then set the interrupt flag TI. Both of these actions occur at S1P1. Reception is initiated by the condition REN = 1 and RI = 0. At the end of the next MCU machine cycle, the RX Control unit writes the bits 11111110 to the receive shift register, and in the next clock phase activates RECEIVE. RECEIVE enables the SHIFT CLOCK signal to the alternate function on the port containing the pin, TxD. Each pulse of SHIFT CLOCK moves the contents of the receive shift register one position to the left while RECEIVE is active. The value that comes in from the right is the value that was sampled at the RxD pin. As data bits come in from the right, 1s shift out to the left. When the 0 that was initially loaded into the rightmost position arrives at the left-most position in the shift register, it flags the RX Control unit to do one last shift, and then it loads SBUF. After this, RECEIVE is cleared, and the receive interrupt flag RI is set.uPSD33xx 86/231 Figure 28. UART Mode 0, Block Diagram Figure 29. UART Mode 0, Timing Diagram AI06824 Zero Detector Internal Bus Tx Control Rx Control Internal Bus SBUF Write to SBUF Read SBUF Load SBUF SBUF Input Shift Register Shift Shift Clock Serial Port Interrupt f OSC/12 REN R1 Rx Clock Start Tx Clock Start Shift Shift Send Receive T R CL D S Q 7 6 5 4 3 2 1 0 RxD P3.0 Alt Input Function RxD Pin TxD Pin AI06825 Write to SBUF Send Shift RxD (Data Out) TxD (Shift Clock) TI Write to SCON RI Receive Shift RxD (Data In) TxD (Shift Clock) Clear RI Receive Transmit D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D787/231 uPSD33xx More About UART Mode 1 Refer to the block diagram in Figure 30., page 88, and timing diagram in Figure 31., page 88. Transmission is initiated by any instruction which writes to SBUF. At the end of a write operation to SBUF, a '1' is loaded into the 9th position of the transmit shift register and flags the TX Control unit that a transmission is requested. Transmission actually starts at the end of the MCU the machine cycle following the next rollover in the divide-by-16 counter. Thus, the bit times are synchronized to the divide-by-16 counter, not to the writing of SBUF. Transmission begins with activation of SEND which puts the start bit at pin TxD. One bit time later, DATA is activated, which enables the output bit of the transmit shift register to pin TxD. The first shift pulse occurs one bit time after that. As data bits shift out to the right, zeros are clocked in from the left. When the MSB of the data byte is at the output position of the shift register, then the 1 that was initially loaded into the 9th position is just to the left of the MSB, and all positions to the left of that contain zeros. This condition flags the TX Control unit to do one last shift and then deactivates SEND, and sets the interrupt flag, TI. This occurs at the 10th divide-by-16 rollover after a write to SBUF. Reception is initiated by a detected 1-to-0 transition at the pin RxD. For this purpose RxD is sampled at a rate of 16 times whatever baud rate has been established. When a transition is detected, the divide-by-16 counter is immediately reset, and 1FFH is written into the input shift register. Resetting the divide-by-16 counter aligns its rollovers with the boundaries of the incoming bit times. The 16 states of the counter divide each bit time into 16ths. At the 7th, 8th, and 9th counter states of each bit time, the bit detector samples the value of RxD. The value accepted is the value that was seen in at least 2 of the 3 samples. This is done for noise rejection. If the value accepted during the first bit time is not '0,' the receive circuits are reset and the unit goes back to looking for another '1'-to- '0' transition. This is to provide rejection of false start bits. If the start bit proves valid, it is shifted into the input shift register, and reception of the reset of the rest of the frame will proceed. As data bits come in from the right, '1s' shift out to the left. When the start bit arrives at the left-most position in the shift register (which in mode 1 is a 9-bit register), it flags the RX Control unit to do one last shift, load SBUF and RB8, and set the receive interrupt flag RI. The signal to load SBUF and RB8, and to set RI, will be generated if, and only if, the following conditions are met at the time the final shift pulse is generated: 1. RI = 0, and 2. Either SM2 = 0, or the received stop bit = 1. If either of these two conditions are not met, the received frame is irretrievably lost. If both conditions are met, the stop bit goes into RB8, the 8 data bits go into SBUF, and RI is activated. At this time, whether the above conditions are met or not, the unit goes back to looking for a '1'-to-'0' transition on pin RxD.uPSD33xx 88/231 Figure 30. UART Mode 1, Block Diagram Figure 31. UART Mode 1, Timing Diagram AI06826 Zero Detector Internal Bus Tx Control Rx Control Internal Bus SBUF Write to SBUF Read SBUF Load SBUF SBUF Input Shift Register Shift Serial Port Interrupt Rx Clock Start Tx Clock Start Shift Shift Send Load SBUF TI RI CL D S Q 1FFh TxD Pin Data Rx Detector RxD Pin 1-to-0 Transition Detector ÷16 Sample ÷16 ÷2 TB8 Timer1 Overflow Timer2 Overflow 0 0 1 1 0 1 TCLK RCLK SMOD AI06843 Write to SBUF Data Shift TxD TI Rx Clock RxD Bit Detector Sample Times Shift RI Receive Transmit D0 D1 D2 D3 D4 D5 D6 D7 Send Tx Clock Start Bit Stop Bit D0 D1 D2 D3 D4 D5 D6 D7 Start Bit Stop Bit89/231 uPSD33xx More About UART Modes 2 and 3 For Mode 2, refer to the block diagram in Figure 32., page 90, and timing diagram in Figure 33., page 90. For Mode 3, refer to the block diagram in Figure 34., page 91, and timing diagram in Figure 35., page 91. Keep in mind that the baud rate is programmable to either 1/32 or 1/64 of fOSC in Mode 2, but Mode 3 uses a variable baud rate generated from Timer 1 or Timer 2 rollovers. The receive portion is exactly the same as in Mode 1. The transmit portion differs from Mode 1 only in the 9th bit of the transmit shift register. Transmission is initiated by any instruction which writes to SBUF. At the end of a write operation to SBUF, the TB8 Bit is loaded into the 9th position of the transmit shift register and flags the TX Control unit that a transmission is requested. Transmission actually starts at the end of the MCU the machine cycle following the next rollover in the divideby-16 counter. Thus, the bit times are synchronized to the divide-by-16 counter, not to the writing of SBUF. Transmission begins with activation of SEND which puts the start bit at pin TxD. One bit time later, DATA is activated, which enables the output bit of the transmit shift register to pin TxD. The first shift pulse occurs one bit time after that. The first shift clocks a '1' (the stop bit) into the 9th bit position of the shift register. There-after, only zeros are clocked in. Thus, as data bits shift out to the right, zeros are clocked in from the left. When bit TB8 is at the output position of the shift register, then the stop bit is just to the left of TB8, and all positions to the left of that contain zeros. This condition flags the TX Control unit to do one last shift and then deactivate SEND, and set the interrupt flag, TI. This occurs at the 11th divide-by 16 rollover after writing to SBUF. Reception is initiated by a detected 1-to-0 transition at pin RxD. For this purpose RxD is sampled at a rate of 16 times whatever baud rate has been established. When a transition is detected, the divide-by-16 counter is immediately reset, and 1FFH is written to the input shift register. At the 7th, 8th, and 9th counter states of each bit time, the bit detector samples the value of RxD. The value accepted is the value that was seen in at least 2 of the 3 samples. If the value accepted during the first bit time is not '0,' the receive circuits are reset and the unit goes back to looking for another '1'-to- '0' transition. If the start bit proves valid, it is shifted into the input shift register, and reception of the rest of the frame will proceed. As data bits come in from the right, '1s' shift out to the left. When the start bit arrives at the left-most position in the shift register (which in Modes 2 and 3 is a 9-bit register), it flags the RX Control unit to do one last shift, load SBUF and RB8, and set the interrupt flag RI. The signal to load SBUF and RB8, and to set RI, will be generated if, and only if, the following conditions are met at the time the final shift pulse is generated: 1. RI = 0, and 2. Either SM2 = 0, or the received 9th data bit = 1. If either of these conditions is not met, the received frame is irretrievably lost, and RI is not set. If both conditions are met, the received 9th data bit goes into RB8, and the first 8 data bits go into SBUF. One bit time later, whether the above conditions were met or not, the unit goes back to looking for a '1'-to-'0' transition on pin RxD.uPSD33xx 90/231 Figure 32. UART Mode 2, Block Diagram Figure 33. UART Mode 2, Timing Diagram AI06844 Zero Detector Internal Bus Tx Control Rx Control Internal Bus SBUF Write to SBUF Read SBUF Load SBUF SBUF Input Shift Register Shift Serial Port Interrupt Rx Clock Start Tx Clock Start Shift Shift Send Load SBUF TI RI CL D S Q 1FFh TxD Pin Data Rx Detector RxD Pin 1-to-0 Transition Detector ÷16 Sample ÷16 ÷2 TB8 f OSC/32 0 1 SMOD AI06845 Write to SBUF Data Shift TxD TI Rx Clock RxD Bit Detector Sample Times Shift RI Receive Transmit D0 D1 D2 D3 D4 D5 D6 D7 Send Tx Clock Start Bit TB8 Stop Bit D0 D1 D2 D3 D4 D5 D6 D7 Start Bit RB8 Stop Bit Stop Bit Generator91/231 uPSD33xx Figure 34. UART Mode 3, Block Diagram Figure 35. UART Mode 3, Timing Diagram AI06846 Zero Detector Internal Bus Tx Control Rx Control Internal Bus SBUF Write to SBUF Read SBUF Load SBUF SBUF Input Shift Register Shift Serial Port Interrupt Rx Clock Start Tx Clock Start Shift Shift Send Load SBUF TI RI CL D S Q 1FFh TxD Pin Data Rx Detector RxD Pin 1-to-0 Transition Detector ÷16 Sample ÷16 ÷2 TB8 Timer1 Overflow Timer2 Overflow 0 0 1 1 0 1 TCLK RCLK SMOD AI06847 Write to SBUF Data Shift TxD TI Rx Clock RxD Bit Detector Sample Times Shift RI Receive Transmit D0 D1 D2 D3 D4 D5 D6 D7 Send Tx Clock Start Bit TB8 Stop Bit D0 D1 D2 D3 D4 D5 D6 D7 Start Bit RB8 Stop Bit Stop Bit GeneratoruPSD33xx 92/231 IrDA INTERFACE uPSD33xx devices provide an internal IrDA interface that will allow the connection of the UART1 serial interface directly to an external infrared transceiver device. The IrDA interface does this by automatically shortening the pulses transmitted on UART1’s TxD1 pin, and stretching the incoming pulses received on the RxD1 pin. Reference Figures 36 and 37. When the IrDA interface is enabled, the output signal from UART1’s transmitter logic on pin TxD1 is compliant with the IrDA Physical Layer Link Specification v1.4 (www.irda.org) operating from 1.2k bps up to 115.2k bps. The pulses received on the RxD1 pin are stretched by the IrDA interface to be recognized by UART1’s receiver logic, also adhering to the IrDA specification up to 115.2k bps. Note: In Figure 37 a logic '0' in the serial data stream of a UART Frame corresponds to a logic high pulse in an IR Frame. A logic '1' in a UART Frame corresponds to no pulse in an IR Frame. Figure 36. IrDA Interface Figure 37. Pulse Shaping by the IrDA Interface UART1 IrDA Interface TxD RxD uPSD33XX IrDA Transceiver TxD1-IrDA RxD1-IrDA SIRClk AI07851 Start Bit 0101 11 1 00 0 Stop Bit UART Frame Data Bits Bit Time Pulse Width = 3/16 Bit Time Start Bit 0101 11 1 00 0 Stop Bit UART Frame IR Frame IR Frame Data Bits AI0962493/231 uPSD33xx The UART1 serial channel can operate in one of four different modes as shown in Table 44., page 81 in the section, SERIAL UART INTERFACES, page 81. However, when UART1 is used for IrDA communication, UART1 must operate in Mode 1 only, to be compatible with IrDA protocol up to 115.2k bps. The IrDA interface will support baud rates generated from Timer 1 or Timer 2, just like standard UART serial communication, but with one restriction. The transmit baud rate and receive baud rate must be the same (cannot be different rates as is allowed by standard UART communications). The IrDA Interface is disabled after a reset and is enabled by setting the IRDAEN Bit in the SFR named IRDACON (Table 48., page 93). When IrDA is disabled, the UART1's RxD and TxD signals will bypass the internal IrDA logic and instead they are routed directly to the pins RxD1 and TxD1 respectively. When IrDA is enabled, the IrDA pulse shaping logic is active and resides between UART1 and the pins RxD1 and TxD1 as shown in Figure 36., page 92. Table 48. IRDACON Register Bit Definition (SFR CEh, Reset Value 0Fh) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – IRDAEN PULSE CDIV4 CDIV3 CDIV2 CDIV1 CDIV0 Details Bit Symbol R/W Definition 7 – – Reserved 6 IRDAEN RW IrDA Enable 0 = IrDA Interface is disabled 1 = IrDA is enabled, UART1 outputs are disconnected from Port 1 (or Port 4) 5 PULSE RW IrDA Pulse Modulation Select 0 = 1.627µs 1 = 3/16 bit time pulses 4-0 CDIV[4:0] RW Specify Clock Divider (see Table 49., page 94)uPSD33xx 94/231 Pulse Width Selection The IrDA interface has two ways to modulate the standard UART1 serial stream: 1. An IrDA data pulse will have a constant pulse width for any bit time, regardless of the selected baud rate. 2. An IrDA data pulse will have a pulse width that is proportional to the the bit time of the selected baud rate. In this case, an IrDA data pulse width is 3/16 of its bit time, as shown in Figure 37., page 92. The PULSE bit in the SFR named IRDACON determines which method above will be used. According to the IrDA physical layer specification, for all baud rates at 115.2k bps and below, the minimum data pulse width is 1.41µs. For a baud rate of 115.2k bps, the maximum pulse width 2.23µs. If a constant pulse width is to be used for all baud rates (PULSE bit = 0), the ideal general pulse width is 1.63µs, derived from the bit time of the fastest baud rate (8.68µs bit time for 115.2k bps rate), multiplied by the proportion, 3/16. To produce this fixed data pulse width when the PULSE bit = 0, a prescaler is needed to generate an internal reference clock, SIRClk, shown in Figure 36., page 92. SIRClk is derived by dividing the oscillator clock frequency, fOSC, using the five bits CDIV[4:0] in the SFR named IRDACON. A divisor must be chosen to produce a frequency for SIRClk that lies between 1.34 MHz and 2.13 MHz, but it is best to choose a divisor value that produces SIRClk frequency as close to 1.83MHz as possible, because SIRClk at 1.83MHz will produce an fixed IrDA data pulse width of 1.63µs. Table 49 provides recommended values for CDIV[4:0] based on several different values of fOSC. For reference, SIRClk of 2.13MHz will generate a fixed IrDA data pulse width of 1.41µs, and SIRClk of 1.34MHz will generate a fixed data pulse width of 2.23µs. Table 49. Recommended CDIV[4:0] Values to Generate SIRClk (default CDIV[4:0] = 0Fh, 15 decimal) Note: 1. When PULSE bit = 0 (fixed data pulse width), this is minimum recommended fOSC because CDIV[4:0] must be 4 or greater. fOSC (MHz) Value in CDIV[4:0] Resulting fSIRCLK (MHz) 40.00 16h, 22 decimal 1.82 36.864, or 36.00 14h, 20 decimal 1.84, or 1.80 24.00 0Dh, 13 decimal 1.84 11.059, or 12.00 06h, 6 decimal 1.84, or 2.00 7.3728(1) 04h, 4 decimal 1.8495/231 uPSD33xx I 2C INTERFACE uPSD33xx devices support one serial I2C interface. This is a two-wire communication channel, having a bi-directional data signal (SDA, pin P3.6) and a clock signal (SCL, pin P3.7) based on opendrain line drivers, requiring external pull-up resistors, RP, each with a typical value of 4.7kΩ (see Figure 38). I 2C Interface Main Features Byte-wide data is transferred, MSB first, between a Master device and a Slave device on two wires. More than one bus Master is allowed, but only one Master may control the bus at any given time. Data is not lost when another Master requests the use of a busy bus because I2C supports collision detection and arbitration. The bus Master initiates all data movement and generates the clock that permits the transfer. Once a transfer is initiated by the Master, any device addressed is considered a Slave. Automatic clock synchronization allows I2C devices with different bit rates to communicate on the same physical bus. A single device can play the role of Master or Slave, or a single device can be a Slave only. Each Slave device on the bus has a unique address, and a general broadcast address is also available. A Master or Slave device has the ability to suspend data transfers if the device needs more time to transmit or receive data. This I2C interface has the following features: – Serial I/O Engine (SIOE): serial/parallel conversion; bus arbitration; clock generation and synchronization; and handshaking are all performed in hardware – Interrupt or Polled operation – Multi-master capability – 7-bit Addressing – Supports standard speed I2C (SCL up to 100kHz), fast mode I2C (101KHz to 400kHz), and high-speed mode I2C (401KHz to 833kHz) Figure 38. Typical I2C Bus Configuration Note: 1. For 3.3V system, connect RP to 3.3V VCC. For 5.0V system, connect RP to 5.0V VDD. I 2C BUS SDA SCL RP RP VCC or VDD(1) Device with I2C Interface Device with I2C Interface SDA/P3.6 SCL/P3.7 uPSD33XX(V) Device with I2C Interface AI09623uPSD33xx 96/231 Communication Flow I 2C data flow control is based on the fact that all I 2C compatible devices will drive the bus lines with open-drain (or open-collector) line drivers pulled up with external resistors, creating a wired-AND situation. This means that either bus line (SDA or SCL) will be at a logic '1' level only when no I2C device is actively driving the line to logic '0.' The logic for handshaking, arbitration, synchronization, and collision detection is implemented by each I2C device having: 1. The ability to hold a line low against the will of the other devices who are trying to assert the line high. 2. The ability of a device to detect that another device is driving the line low against its will. Assert high means the driver releases the line and external pull-ups passively raise the signal to logic '1.' Holding low means the open-drain driver is actively pulling the signal to ground for a logic '0.' For example, if a Slave device cannot transmit or receive a byte because it is distracted by and interrupt or it has to wait for some process to complete, it can hold the SCL clock line low. Even though the Master device is generating the SCL clock, the Master will sense that the Slave is holding the SCL line low against the will of the Master, indicating that the Master must wait until the Slave releases SCL before proceeding with the transfer. Another example is when two Master devices try to put information on the bus simultaneously, the first one to release the SDA data line looses arbitration while the winner continues to hold SDA low. Two types of data transfers are possible with I2C depending on the R/W bit, see Figure 39., page 97. 1. Data transfer from Master Transmitter to Slave Receiver (R/W = 0). In this case, the Master generates a START condition on the bus and it generates a clock signal on the SCL line. Then the Master transmits the first byte on the SDA line containing the 7-bit Slave address plus the R/W bit. The Slave who owns that address will respond with an acknowledge bit on SDA, and all other Slave devices will not respond. Next, the Master will transmit a data byte (or bytes) that the addressed Slave must receive. The Slave will return an acknowledge bit after each data byte it successfully receives. After the final byte is transmitted by the Master, the Master will generate a STOP condition on the bus, or it will generate a RESTART conditon and begin the next transfer. There is no limit to the number of bytes that can be transmitted during a transfer session. 2. Data transfer from Slave Transmitter to Master Receiver (R/W = 1). In this case, the Master generates a START condition on the bus and it generates a clock signal on the SCL line. Then the Master transmits the first byte on the SDA line containing the 7-bit Slave address plus the R/W bit. The Slave who owns that address will respond with an acknowledge bit on SDA, and all other Slave devices will not respond. Next, the addressed Slave will transmit a data byte (or bytes) to the Master. The Master will return an acknowledge bit after each data byte it successfully receives, unless it is the last byte the Master desires. If so, the Master will not acknowledge the last byte and from this, the Slave knows to stop transmitting data bytes to the Master. The Master will then generate a STOP condition on the bus, or it will generate a RE-START conditon and begin the next transfer. There is no limit to the number of bytes that can be transmitted during a transfer session. A few things to know related to these transfers: – Either the Master or Slave device can hold the SCL clock line low to indicate it needs more time to handle a byte transfer. An indefinite holding period is possible. – A START condition is generated by a Master and recognized by a Slave when SDA has a 1- to-0 transition while SCL is high (Figure 39., page 97). – A STOP condition is generated by a Master and recognized by a Slave when SDA has a 0- to1 transition while SCL is high (Figure 39., page 97). – A RE-START (repeated START) condition generated by a Master can have the same function as a STOP condition when starting another data transfer immediately following the previous data transfer (Figure 39., page 97). – When transferring data, the logic level on the SDA line must remain stable while SCL is high, and SDA can change only while SCL is low. However, when not transferring data, SDA may change state while SCL is high, which creates the START and STOP bus conditions.97/231 uPSD33xx – An Acknowlegde bit is generated from a Master or a Slave by driving SDA low during the “ninth” bit time, just following each 8-bit byte that is transfered on the bus (Figure 39., page 97). A Non-Acknowledge occurs when SDA is asserted high during the ninth bit time. All byte transfers on the I2C bus include a 9th bit time reserved for an Acknowlege (ACK) or Non-Acknowledge (NACK). – An additional Master device that desires to control the bus should wait until the bus is not busy before generating a START condition so that a possible Slave operation is not interrupted. – If two Master devices both try to generate a START condition simultaneously, the Master who looses arbitration will switch immediately to Slave mode so it can recoginize it’s own Slave address should it appear on the bus. Figure 39. Data Transfer on an I2C Bus MSB 7-bit Slave Address READ/WRITE Indicator Acknowledge bits from receiver Start Condition Clock can be held low to stall transfer. Repeated if more data bytes are transferred. Repeated Start Condition Stop Condition 12 789 3-6 1 2 9 3-8 ACK MSB ACK NACK R/W AI09625uPSD33xx 98/231 Operating Modes The I2C interface supports four operating modes: ■ Master-Transmitter ■ Master-Receiver ■ Slave-Transmitter ■ Slave-Receiver The interface may operate as either a Master or a Slave within a given application, controlled by firmware writing to SFRs. By default after a reset, the I2C interface is in Master Receiver mode, and the SDA/P3.6 and SCL/ P3.7 pins default to GPIO input mode, high impedance, so there is no I2C bus interference. Before using the I2C interface, it must be initialized by firmware, and the pins must be configured. This is discussed in I 2C Operating Sequences, page 108. Bus Arbitration A Master device always samples the I2C bus to ensure a bus line is high whenever that Master is asserting a logic 1. If the line is low at that time, the Master recognizes another device is overriding it’s own transmission. A Master may start a transfer only if the I2C bus is not busy. However, it’s possible that two or more Masters may generate a START condition simultaneously. In this case, arbitration takes place on the SDA line each time SCL is high. The Master that first senses that its bus sample does not correspond to what it is driving (SDA line is low while it’s asserting a high) will immediately change from Master-Transmitter to Slave-Receiver mode. The arbitration process can carry on for many bit times if both Masters are addressing the same Slave device, and will continue into the data bits if both Masters are trying to be Master-Transmitter. It is also possible for arbitration to carry on into the acknowledge bits if both Masters are trying to be Master-Receiver. Because address and data information on the bus is determined by the winning Master, no information is lost during the arbitration process. Clock Synchronization Clock synchronization is used to synchronize arbitrating Masters, or used as a handshake by a devices to slow down the data transfer. Clock Sync During Arbitration. During bus arbitration between competing Masters, Master_X, with the longest low period on SCL, will force Master_Y to wait until Master_X finishes its low period before Master_Y proceeds to assert its high period on SCL. At this point, both Masters begin asserting their high period on SCL simultaneously, and the Master with the shortest high period will be the first to drive SCL for the next low period. In this scheme, the Master with the longest low SCL period paces low times, and the Master with the shortest high SCL period paces the high times, making synchronized arbitration possible. Clock Sync During Handshaking. This allows receivers in different devices to handle various transfer rates, either at the byte-level, or bit-level. At the byte-level, a device may pause the transfer between bytes by holding SCL low to have time to store the latest received byte or fetch the next byte to transmit. At the bit-level, a Slave device may extend the low period of SCL by holding it low. Thus the speed of any Master device will adapt to the internal operation of the Slave. General Call Address A General Call (GC) occurs when a Master-Transmitter initiates a transfer containing a Slave address of 0000000b, and the R/W bit is logic 0. All Slave devices capable of responding to this broadcast message will acknowledge the GC simultaneously and then behave as a Slave-Receiver. The next byte transmitted by the Master will be accepted and acknowledged by all Slaves capable of handling the special data bytes. A Slave that cannot handle one of these data bytes must ignore it by not acknowledging it. The I2C specification lists the possible meanings of the special bytes that follow the first GC address byte, and the actions to be taken by the Slave device(s) upon receiving them. A common use of the GC by a Master is to dynamically assign device addresses to Slave devices on the bus capable of a programmable device address. The uPSD33xx can generate a GC as a MasterTransmitter, and it can receive a GC as a Slave. When receiving a GC address (00h), an interrupt will be generated so firmware may respond to the special GC data bytes if desired.99/231 uPSD33xx Serial I/O Engine (SIOE) At the heart of the I2C interface is the hardware SIOE, shown in Figure 40. The SIOE automatically handles low-level I2C bus protocol (data shifting, handshaking, arbitration, clock generation and synchronization) and it is controlled and monitored by five SFRs. The five SFRs shown in Figure 40 are: ■ S1CON - Interface Control (Table 50., page 100) ■ S1STA - Interface Status (Table 52., page 103) ■ S1DAT - Data Shift Register (Table 53., page 104) ■ S1ADR - Device Address (Table 54., page 104) ■ S1SETUP - Sampling Rate (Table 55., page 105) Figure 40. I2C Interface SIOE Block Diagram OpenDrain Output Input OpenDrain Output Input Comparator S1SETUP - Sample Rate Control (START Condition) S1STA - Interface Status S1CON - Interface Control ACK Bit SCL / P3.7 Timing and Control Clock Generation Arbitration and Sync Periph Clock (fOSC) SDA / P3.6 8032 MCU Bus INTR to 8032 S1DAT - Shift Register Serial DATA IN Serial DATA OUT Shift Direction 8 8 8 8 8 7 7 b7 b0 S1ADR - Device Address b7 b0 AI09626uPSD33xx 100/231 I 2C Interface Control Register (S1CON) Table 50. Serial Control Register S1CON (SFR DCh, Reset Value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 CR2 ENI1 STA STO ADDR AA CR[1:0] Details Bit Symbol R/W Function 7 CR2 R,W This bit, along with bits CR1 and CR0, determine the SCL clock frequency (fSCL) when SIOE is in Master mode. These bits create a clock divisor for fOSC. See Table 51. 6 ENI1 R,W I 2C Interface Enable 0 = SIOE disabled, 1 = SIOE enabled. When disabled, both SDA and SCL signals are in high impedance state. 5 STA R,W START flag. When set, Master mode is entered and SIOE generates a START condition only if the I2C bus is not busy. When a START condition is detected on the bus, the STA flag is cleared by hardware. When the STA bit is set during an interrupt service, the START condition will be generated after the interrupt service. 4 STO R,W STOP flag When STO is set in Master mode, the SIOE generates a STOP condition. When a STOP condition is detected, the STO flag is cleared by hardware. When the STO bit is set during an interrupt service, the STOP condition will be generated after the interrupt service. 3 ADDR R,W This bit is set when an address byte received in Slave mode matches the device address programmed into the S1ADR register. The ADDR bit must be cleared with firmware. 2 AA R,W Assert Acknowledge enable If AA = 1, an acknowledge signal (low on SDA) is automatically returned during the acknowledge bit-time on the SCL line when any of the following three events occur: 1. SIOE in Slave mode receives an address that matches contents of S1ADR register 2. A data byte has been received while SIOE is in Master Receiver mode 3. A data byte has been received while SIOE is a selected Slave Receiver When AA = 0, no acknowledge is returned (high on SDA during acknowledge bit-time). 1, 0 CR1, CR0 R,W These bits, along with bit CR2, determine the SCL clock frequency (fSCL) when SIOE is in Master mode. These bits create a clock divisor for fOSC. See Table 51 for values.101/231 uPSD33xx Table 51. Selection of the SCL Frequency in Master Mode based on fOSC Examples Note: 1. These values are beyond the bit rate supported by uPSD33xx. CR2 CR1 CR0 fOSC Divided by: Bit Rate (kHz) @ fOSC 12MHz fOSC 24MHz fOSC 36MHz fOSC 40MHz fOSC 0 0 0 32 375 750 X(1) X(1) 0 0 1 48 250 500 750 833 0 1 0 60 200 400 600 666 0 1 1 120 100 200 300 333 1 0 0 240 50 100 150 166 1 0 1 480 25 50 75 83 1 1 0 960 12.5 25 37.5 41 1 1 1 1920 6.25 12.5 18.75 20uPSD33xx 102/231 I 2C Interface Status Register (S1STA) The S1STA register provides status regarding immediate activity and the current state of operation on the I2C bus. All bits in this register are read-only except bit 5, INTR, which is the interrupt flag. Interrupt Conditions. If the I2C interrupt is enabled (EI2C = 1 in SFR named IEA, and EA =1 in SFR named IE), and the SIOE is initialized, then an interrupt is automatically generated when any one of the following five events occur: – When the SIOE receives an address that matches the contents of the SFR, S1ADR. Requirements: SIOE is in Slave Mode, and bit AA = 1 in the SFR S1CON. – When the SIOE receives General Call address. Requirments: SIOE is in Slave Mode, bit AA = 1 in the SFR S1CON – When a complete data byte has been received or transmitted by the SIOE while in Master mode. The interrupt will occur even if the Master looses arbitration. – When a complete data byte has been received or transmitted by the SIOE while in selected Slave mode. – A STOP condition on the bus has been recognized by the SIOE while in selected Slave mode. Selected Slave mode means the device address sent by the Master device at the beginning of the current data transfer matched the address stored in the S1ADR register. If the I2C interrupt is not enabled, the MCU may poll the INTR flag in S1STA.103/231 uPSD33xx Table 52. S1STA: I2C Interface Status Register (SFR DDh, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 GC STOP INTR TX_MODE BBUSY BLOST ACK_RESP SLV Details Bit Symbol R/W Function 7 GC R General Call flag GC = 1 if the General Call address of 00h was received when SIOE is in Slave mode, and GC is cleared by a START or STOP condition on the bus. If the SIOE is in Master mode when GC = 1, the Bus Lost condition exists, and BLOST = 1. 6 STOP R STOP flag STOP = 1 while SIOE detects a STOP condition on the bus when in Master or Slave mode. 5 INTR R,W Interrupt flag INTR is set to 1 by any of the five I2C interrupt conditions listed above. INTR must be cleared by firmware. 4 TX_MODE R Transmission Mode flag TX_MODE = 1 whenever the SIOE is in Master-Transmitter or SlaveTransmitter mode. TX_MODE = 0 when SIOE is in any receiver mode. 3 BBUSY R Bus Busy flag BBUSY = 1 when the I2C bus is in use. BBUSY is set by the SIOE when a START condition exists on the bus and BBUSY is cleared by a STOP condition. 2 BLOST R Bus Lost flag BLOST is set when the SIOE is in Master mode and it looses the arbitration process to another Master device on the bus. 1 ACK_RESP R Not Acknowledge Response flag While SIOE is in Transmitter mode: – After SIOE sends a byte, ACK_RESP = 1 whenever the external I2C device receives the byte, but that device does NOT assert an ackowledge signal (external device asserted a high on SDA during the acknowledge bit-time). – After SIOE sends a byte, ACK_RESP = 0 whenever the external I2C device receives the byte, and that device DOES assert an ackowledge signal (external device drove a low on SDA during the acknowledge bit-time) Note: If SIOE is in Master-Transmitter mode, and ACK_RESP = 1 due to a Slave-Transmitter not sending an Acknowledge, a STOP condition will not automatically be generated by the SIOE. The STOP condition must be generated with S1CON.STO = 1. 0 SLV R Slave Mode flag SLV = 1 when the SIOE is in Slave mode. SLV = 0 when the SIOE is in Master mode (default).uPSD33xx 104/231 I 2C Data Shift Register (S1DAT) The S1ADR register (Table 53) holds a byte of serial data to be transmitted or it holds a serial byte that has just been received. The MCU may access S1DAT while the SIOE is not in the process of shifting a byte (the INTR flag indicates shifting is complete). While transmitting, bytes are shifted out MSB first, and when receiving, bytes are shifted in MSB first, through the Acknowledge Bit register as shown in Figure 40., page 99. Bus Wait Condition. After the SIOE finishes receiving a byte in Receive mode, or transmitting a byte in Transmit mode, the INTR flag (in S1STA) is set and automatically a wait condition is imposed on the I2C bus (SCL held low by SIOE). In Transmit mode, this wait condition is released as soon as the MCU writes any byte to S1DAT. In Receive mode, the wait condition is released as soon as the MCU reads the S1DAT register. This method allows the user to handle transmit and receive operations within an interrupt service routine. The SIOE will automatically stall the I2C bus at the appropriate time, giving the MCU time to get the next byte ready to transmit or time to read the byte that was just received. Table 53. S1DAT: I2C Data Shift register (SFR DEh, reset value 00h) I 2C Address Register (S1ADR) The S1ADR register (Table 54) holds the 7-bit device address used when the SIOE is operating as a Slave. When the SIOE receives an address from a Master, it will compare this address to the contents of S1ADR, as shown in Figure 40., page 99. If the 7 bits match, the INTR Interrupt flag (in S1STA) is set, and the ADDR Bit (in S1CON) is set. The SIOE cannot modify the contents S1ADR, and S1ADR is not used during Master mode. Table 54. S1ADR: I2C Address register (SFR DFh, reset value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 S1DAT[7:0] Details Bit Symbol R/W Function 7:0 S1DAT[7:0] R/W Holds the data byte to be transmitted in Transmit mode, or it holds the data byte received in Receiver mode. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SLA6 SLA5 SLA4 SLA3 SLA2 SLA1 SLA0 – Details Bit Symbol R/W Function 7:1 SLA[6:0] R/W Stores desired 7-bit device address, used when SIOE is in Slave mode. 0 – – Not used105/231 uPSD33xx I 2C START Sample Setting (S1SETUP) The S1SETUP register (Table 55) determines how many times an I2C bus START condition will be sampled before the SIOE validates the START condition, giving the SIOE the ability to reject noise or illegal transmissions. Because the minimum duration of an START condition varies with I2C bus speed (fSCL), and also because the uPSD33xx may be operated with a wide variety of frequencies (fOSC), it is necessary to scale the number of samples per START condition based on fOSC and fSCL. In Slave mode, the SIOE recognizes the beginning of a START condition when it detects a '1'-to-'0' transition on the SDA bus line while the SCL line is high (see Figure 39., page 97). The SIOE must then validate the START condition by sampling the bus lines to ensure SDA remains low and SCL remains high for a minimum amount of hold time, tHLDSTA. Once validated, the SIOE begins receiving the address byte that follows the START condition. If the EN_SS Bit (in the S1SETUP Register) is not set, then the SIOE will sample only once after detecting the '1'-to-'0' transition on SDA. This single sample is taken 1/fOSC seconds after the initial 1- to-0 transition was detected. However, more samples should be taken to ensure there is a valid START condition. To take more samples, the SIOE should be initialized such that the EN_SS Bit is set, and a value is written to the SMPL_SET[6:0] field of the S1SETUP Register to specify how many samples to take. The goal is to take a good number of samples during the minimum START condition hold time, tHLDSTA, but no so many samples that the bus will be sampled after tHLDSTA expires. Table 56., page 106 describes the relationship between the contents of S1SETUP and the resulting number of I2C bus samples that SIOE will take after detecting the 1-to-0 transition on SDA of a START condition. Important: Keep in mind that the time between samples is always 1/fOSC. The minimum START condition hold time, tHLDSTA, is different for the three common I2C speed categories per Table 57., page 106. Table 55. S1SETUP: I2C START Condition Sample Setup register (SFR DBh, reset value 00h) Note: 1. Sampling SCL and SDA lines begins after '1'-to-'0' transition on SDA occurred while SCL is high. Time between samples is 1/fOSC. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 EN_SS SMPL_SET[6:0] Details Bit Symbol R/W Function 7 EN_SS R/W Enable Sample Setup EN_SS = 1 will force the SIOE to sample(1) a START condition on the bus the number of times specified in SMPL_SET[6:0]. EN_SS = 0 means the SIOE will sample(1) a START condition only one time, regardless of the contents of SMPL_SET[6:0]. 6:0 SMPL_SET [6:0] – Sample Setting Specifies the number of bus samples(1) taken during a START condition. See Table 56 for values.uPSD33xx 106/231 Table 56. Number of I2C Bus Samples Taken after 1-to-0 Transition on SDA (START Condition) Table 57. Start Condition Hold Time Note: 1. 833KHz is maximum for uPSD33xx devices. Contents of S1SETUP Resulting value for S1SETUP Resulting Number of Samples Taken After 1-to-0 on SDA Line SS_EN bit SMPL_SET[6:0] 0 XXXXXXXb 00h (default) 1 1 0000000b 80h 1 1 0000001b 81h 2 1 0000010b 82h 3 ... ... ... ... 1 0001011b 8Bh 12 1 0010111b 97h 24 ... ... ... ... 1 1111111b FFh 128 I 2C Bus Speed Range of I2C Clock Speed (fSCL) Minimum START Condition Hold Time (tHLDSTA) Standard Up to 100KHz 4000ns Fast 101KHz to 400KHz 600ns High 401KHz to 833KHz(1) 160ns107/231 uPSD33xx Table 58 provides recommended settings for S1SETUP based on various combinations of fOSC and fSCL. Note that the “Total Sample Period” times in Table 57., page 106 are typically slightly less than the minimum START condition hold time, tHLDSTA for a given I2C bus speed. Important: The SCL bit rate fSCL must first be determined by bits CR[2:0] in the SFR S1CON before a value is chosen for SMPL_SET[6:0] in the SFR S1SETUP. Table 58. S1SETUP Examples for Various I2C Bus Speeds and Oscillator Frequencies Note: 1. Not compatible with High Speed I2C. I 2C Bus Speed, fSCL Parameter Oscillator Frequency, fOSC 6 MHz 12 MHz 24 MHz 33 MHz 40 MHz Standard Recommended S1SETUP Value 93h A7h CFh EEh FFh Number of Samples 20 40 80 111 128 Time Between Samples 166.6ns 83.3ns 41.6ns 30ns 25ns Total Sampled Period 3332ns 3332ns 3332ns 3333ns 3200ns Fast Recommended S1SETUP Value 82h 85h 8Bh 90h 93h Number of Samples 3 6 12 17 20 Time Between Samples 166.6ns 83.3ns 41.6ns 30ns 25ns Total Sampled Period 500ns 500ns 500ns 510ns 500ns High Recommended S1SETUP Value (Note 1) 80 82 83 84 Number of Samples - 1 3 4 5 Time Between Samples - 83.3ns 41.6ns 30ns 25ns Total Sampled Period - 83.3 125ns 120ns 125nsuPSD33xx 108/231 I 2C Operating Sequences The following pseudo-code explains hardware control for these I2C functions on the uPSD33xx: – Initialize the Interface – Function as Master-Transmitter – Function as Master-Receiver – Function as Slave-Transmitter – Function as Slave-Receiver – Interrupt Service Routine Full C code drivers for the uPSD33xx I2C interface, and other interfaces are available from the web at www.st.com\psm. Initialization after a uPSD33xx reset Ensure pins P3.6 and P3.7 are GPIO inputs – SFR P3.7 = 1 and SFR P3.6 = 1 Configure pins P3.6 and P3.7 as I2C – SFR P3SFS.6 = 1 and P3SFS.7 = 1 Set I2C clock prescaler to determine fSCL – SFR S1CON.CR[2:0] = desired SCL freq. Set bus START condition sampling – SFR S1SETUP[7:0] = number of samples Enable individual I2C interrupt and set priority – SFR IEA.I2C = 1 – SFR IPA.I2C = 1 if high priority is desired Set the Device address for Slave mode – SFR S1ADR = XXh, desired address Enable SIOE (as Slave) to return an ACK signal – SFR S1CON.AA = 1 Master-Transmitter Disable all interrupts – SFR IE.EA = 0 Set pointer to global data xmit buffer, set count – *xmit_buf = *pointer to data – buf_length = number of bytes to xmit Set global variables to indicate Master-Xmitter – I2C_master = 1, I2C_xmitter = 1 Disable Master from returning an ACK – SFR S1CON.AA = 0 Enable I2C SIOE – SFR S1CON.INI1 = 1 Transmit Address and R/W bit = 0 to Slave – Is bus not busy? (SFR S1STA.BBUSY = 0?) – SFR S1DAT[7:0] = Load Slave Address & FEh – SFR S1CON.STA = 1, send START on bus Enable All Interrupts and go do something else – SFR IE.EA = 1 Master-Receiver Disable all interrupts – SFR IE.EA = 0 Set pointer to global data recv buffer, set count – *recv_buf = *pointer to data – buf_length = number of bytes to recv Set global variables to indicate Master-Xmitter – I2C_master = 1, I2C_xmitter = 0 Disable Master from returning an ACK – SFR S1CON.AA = 0 Enable I2C SIOE – SFR S1CON.INI1 = 1 Transmit Address and R/W bit = 1 to Slave – Is bus not busy? (SFR S1STA.BBUSY = 0?) – SFR S1DAT[7:0] = Load Slave Address # 01h – SFR S1CON.STA = 1, send START on bus Enable All Interrupts and go do something else – SFR IE.EA = 1109/231 uPSD33xx Slave-Transmitter Disable all interrupts – SFR IE.EA = 0 Set pointer to global data xmit buffer, set count – *xmit_buf = *pointer to data – buf_length = number of bytes to xmit Set global variables to indicate Master-Xmitter – I2C_master = 0, I2C_xmitter = 1 Enable SIOE – SFR S1CON.INI1 = 1 Prepare to Xmit first data byte – SFR S1DAT[7:0] = xmit_buf[0] Enable All Interrupts and go do something else – SFR IE.EA = 1 Slave-Receiver Disable all interrupts – SFR IE.EA = 0 Set pointer to global data recv buffer, set count – *recv_buf = *pointer to data – buf_length = number of bytes to recv Set global variables to indicate Master-Xmitter – I2C_master = 0, I2C_xmitter = 0 Enable SIOE – SFR S1CON.INI1 = 1 Enable All Interrupts and go do something else – SFR IE.EA = 1 Interrupt Service Routine (ISR). A typical I2C interrupt service routine would handle a interrupt for any of the four combinations of Master/Slave and Transmitter/Receiver. In the example routines above, the firmware sets global variables, I2C_master and I2C_xmitter, before enabling interrupts. These flags tell the ISR which one of the four cases to process. Following is pseudo-code for high-level steps in the I2C ISR: Begin I2C ISR : Clear I2C interrupt flag: – S1STA.INTR = 0 Read status of SIOE, put in to variable, status – status = S1STA Read global variables that determine the mode – mode <= (I2C_master, I2C_slave) If mode is Master-Transmitter Bus Arbitration lost? (status.BLOST=1?) If Yes, Arbitration was lost: – S1DAT = dummy, write to release bus – Exit ISR, SIOE will switch to Slave Recv mode If No, Arbitration was not lost, continue: ACK recvd from Slave? (status.ACK_RESP=0?) If No, an ACK was not received: – S1CON.STO = 1, set STOP bus condition – – S1DAT = dummy, write to release bus – Exit ISR If Yes, ACK was received, then continue: – S1DAT = xmit_buf[buffer_index], transmit byte Was that the last byte of data to transmit? If No, it was not the last byte, then: – Exit ISR, transmit next byte on next interrupt If Yes, it was the last byte, then: – S1CON.STO = 1, set STOP bus condition – S1DAT = dummy, write to release bus – Exit ISRuPSD33xx 110/231 Else If mode is Master-Receiver: Bus Arbitration lost? (status.BLOST=1?) If Yes, Arbitration was lost: – S1DAT = dummy, write to release bus – Exit ISR, SIOE will switch to Slave Recv mode If No, Aribitration was not lost, continue: Is this Interrupt from sending an address to Slave, or is it from receiving a data byte from Slave? If its from sending Slave address, goto A: If its from receiving Slave data, goto B: A: (Interrupt is from Master sending addr to Slave) ACK recvd from Slave? (status.ACK_RESP=0?) If No, an ACK was not received: – S1CON.STO = 1, set STOP condition – dummy = S1DAT, read to release bus – Exit ISR If Yes, ACK was received, then continue: – dummy = S1DAT, read to release bus Does Master want to receive just one data byte? If Yes, do not allow Master to ACK on next interrupt: – Exit ISR, now ready to recv one byte from Slv If No, Master can ACK next byte from Slv – S1CON.AA = 1, allow Master to send ACK – Exit ISR, now ready to recv data from Slave B: (Interrupt is from Master recving data from Slv) – recv_buf[buffer_index] = S1DAT, read byte Is this the last data byte to receive from Slave? If Yes, tell Slave to stop transmitting: – S1CON.STO = 1, set STOP bus condition – Exit ISR, finished receiving data from Slave If No, continue: Is this the next to last byte to receive from Slave? If this is the next to last byte, do not allow Master to ACK on next interrupt. – S1CON.AA = 0, don’t let Master return ACK – Exit ISR, now ready to recv last byte from Slv If this is not next to last byte, let Master send ACK to Slave – Exit ISR, ready to recv more bytes from Slave Else If mode is Slave-Transmitter: Is this Intr from SIOE detecting a STOP on bus? If Yes, a STOP was detected: – S1DAT = dummy, write to release bus – Exit ISR, Master needs no more data bytes If No, a STOP was not detected, continue: ACK recvd from Master? (status.ACK_RESP=0?) If No, an ACK was not received: – S1DAT = dummy, write to release bus – Exit ISR, Master needs no more data bytes If Yes, ACK was received, then continue: – S1DAT = xmit_buf[buffer_index], transmit byte – Exit ISR, transmit next byte on next interrupt111/231 uPSD33xx Else If mode is Slave-Receiver: Is this Intr from SIOE detecting a STOP on bus? If Yes, a STOP was detected: – recv_buf[buffer_index] = S1DAT, get last byte – Exit ISR, Master has sent last byte If No, a STOP was not detected, continue: Determine if this Interrupt is from receiving an address or a data byte from a Master. Is (S1CON.ADDR = 1 and S1CON.AA =1)? If No, intr is from receiving data, goto C: If Yes, intr is from an address, continue: – slave_is_adressed = 1, local variable set true – S1CON.ADDR = 0, clear address match flag Determine if R/W bit indicates transmit or receive. Does status.TX_MODE = 1? If Yes, Master wants transmit mode – Exit ISR, indicate Master wants Slv-Xmit mode If No, Master wants Slave-Recv mode – dummy = S1DAT, read taran se bueuPSD33xx 112/231 SPI (SYNCHRONOUS PERIPHERAL INTERFACE) uPSD33xx devices support one serial SPI interface in Master Mode only. This is a three- or fourwire synchronous communication channel, capable of full-duplex operation on 8-bit serial data transfers. The four SPI bus signals are: ■ SPIRxD Pin P1.5 or P4.5 receives data from the Slave SPI device to the uPSD33xx ■ SPITxD Pin P1.6 or P4.6 transmits data from the uPSD33xx to the Slave SPI device ■ SPICLK Pin P1.4 or P4.4 clock is generated from the uPSD33xx to the SPI Slave device ■ SPISEL Pin P1.7 or P4.7 selects the signal from the uPSD33xx to an individual Slave SPI device This SPI interface supports single-Master/multiple-Slave connections. Multiple-Master connections are not directly supported by the uPSD33xx (no internal logic for collision detection). If more than one Slave device is required, the SPISEL signal may be generated from uPSD33xx GPIO outputs (one for each Slave) or from the PLD outputs of the PSD Module. Figure 41. illustrates three examples of SPI device connections using the uPSD33xx: ■ Single-Master/Single-Slave with SPISEL ■ Single-Master/Single-Slave without SPISEL ■ Single-Master/Multiple-Slave without SPISEL Figure 41. SPI Device Connection Examples SPI Bus SPI Bus SPI Bus SPITxD SPIRxD uPSD33xx SPI Master SPI Slave SPICLK Device SPISEL AI07853b MOSI MISO SCLK Single-Master/Single-Slave, with SPISEL Single-Master/Single-Slave, without SPISEL Single-Master/Multiple-Slave, without SPISEL SS SPI Slave Device MOSI MISO SCLK SS SPI Slave Device MOSI MISO SCLK SS SS SPITxD SPIRxD uPSD33xx SPI Master SPI Slave SPICLK Device SPITxD SPIRxD uPSD33xx SPI Master SPICLK GPIO or PLD GPIO or PLD MOSI MISO SCLK113/231 uPSD33xx SPI Bus Features and Communication Flow The SPICLK signal is a gated clock generated from the uPSD33xx (Master) and regulates the flow of data bits. The Master may transmit at a variety of baud rates, and the SPICLK signal will clock one period for each bit of transmitted data. Data is shifted on one edge of SPICLK and sampled on the opposite edge. The SPITxD signal is generated by the Master and received by the Slave device. The SPIRxD signal is generated by the Slave device and received by the Master. There may be no more than one Slave device transmitting data on SPIRxD at any given time in a multi-Slave configuration. Slave selection is accomplished when a Slave’s “Slave Select” (SS) input is permanently grounded or asserted active-low by a Master device. Slave devices that are not selected do not interfere with SPI activities. Slave devices ignore SPICLK and keep their MISO output pins in high-impedance state when not selected. The SPI specification allows a selection of clock polarity and clock phase with respect to data. The uPSD33xx supports the choice of clock polarity, but it does not support the choice of clock phase (phase is fixed at what is typically known as CPHA = 1). See Figure 43. and Figure 44., page 114 for SPI data and clock relationships. Referring to these figures (43 and 44), when the phase mode is defined as such (fixed at CPHA =1), in a new SPI data frame, the Master device begins driving the first data bit on SPITxD at the very first edge of the first clock period of SPICLK. The Slave device will use this first clock edge as a transmission start indicator, and therefore the Slave’s Slave Select input signal may remain grounded in a single-Master/single-Slave configuration (which means the user does not have to use the SPISEL signal from uPSD33xx in this case). The SPI specification does not specify high-level protocol for data exchange, only low-level bit-serial transfers are defined. Full-Duplex Operation When an SPI transfer occurs, 8 bits of data are shifted out on one pin while a different 8 bits of data are simultaneously shifted in on a second pin. Another way to view this transfer is that an 8-bit shift register in the Master and another 8-bit shift register in the Slave are connected as a circular 16-bit shift register. When a transfer occurs, this distributed shift register is shifted 8 bit positions; thus, the data in the Master and Slave devices are effectively exchanged (see Figure 42.). Bus-Level Activity Figure 43. details an SPI receive operation (with respect to bus Master) and Figure 44. details an SPI transmit operation. Also shown are internal flags available to firmware to manage data flow. These flags are accessed through a number of SFRs. Note: The uPSD33xx SPI interface SFRs allow the choice of transmitting the most significant bit (MSB) of a byte first, or the least significant bit (LSB) first. The same bit-order applies to data reception. Figures 43 and 44 illustrate shifting the LSB first. Figure 42. SPI Full-Duplex Data Exchange SPI Bus Master Device Slave Device AI10485 SS SPITxD SPIRxD Baud Rate Generator 8-Bit Shift Register 8-Bit Shift Register SPICLK MOSI MISO SCLKuPSD33xx 114/231 Figure 43. SPI Receive Operation Example Figure 44. SPI Transmit Operation Example Bit7 SPICLK (SPO=0) SPICLK (SPO=1) SPIRXD Bit0 Bit1 Bit7 Bit0 Bit1 Bit7 1 frame RISF RORIS BUSY SPIINTR SPIRDR Full interrupt requested Interrupt handler read data in SPIRDR SPIRDR Full interrupt requested Transmit End interrupt requested AI07855 Bit0 SPICLK (SPO=0) SPICLK (SPO=1) SPITXD Bit1 Bit7 Bit0 Bit1 Bit7 1 frame TISF TEISF BUSY SPIINTR SPITDR Empty interrupt requested Interrupt handler write data in TDR SPITDR Empty interrupt requested Transmit End interrupt requested SPISEL AI07854115/231 uPSD33xx SPI SFR Registers Six SFR registers control the SPI interface: ■ SPICON0 (Table 59., page 117) for interface control ■ SPICON1 (Table 60., page 118) for interrupt control ■ SPITDR (SFR D4h, Write only) holds byte to transmit ■ SPIRDR (SFR D5h, Read only) holds byte received ■ SPICLKD (Table 61., page 118) for clock divider ■ SPISTAT (Table 62., page 119) holds interface status The SPI interface functional block diagram (Figure 45.) shows these six SFRs. Both the transmit and receive data paths are double-buffered, meaning that continuous transmitting or receiving (back-toback transfer) is possible by reading from SPIRDR or writing data to SPITDR while shifting is taking place. There are a number of flags in the SPISTAT register that indicate when it is full or empty to assist the 8032 MCU in data flow management. When enabled, these status flags will cause an interrupt to the MCU. Figure 45. SPI Interface, Master Mode Only SPITDR - TRANSMIT REGISTER SPITxD / P1.6 or P4.6 TIMING AND CONTROL (fOSC) INTR to 8032 SPIRDR - RECEIVE REGISTER 8-bit SHIFT REGISTER 8 8 8 8 SPIRxD / P1.5 or P4.5 SPICON0, SPICON1 - CONTROL REGISTERS 8 SPISTAT - STATUS REGISTER 8 8032 MCU DATA BUS CLOCK GENERATE SPISEL / P1.7 or P4.7 CLOCK SPICLK / P1.4 or P4.4 DIVIDE ÷1 ÷4 ÷8 ÷16 ÷32 ÷64 ÷128 SPICLKD - DIVIDE SELECT 8 PERIPH_CLK AI10486uPSD33xx 116/231 SPI Configuration The SPI interface is reset by the MCU reset, and firmware needs to initialize the SFRs SPICON0, SPICON1, and SPICLKD to define several operation parameters. The SPO Bit in SPICON0 determines the clock polarity. When SPO is set to '0,' a data bit is transmitted on SPITxD from one rising edge of SPICLK to the next and is guaranteed to be valid during the falling edge of SPICLK. When SPO is set to '1,' a data bit is transmitted on SPITxD from one falling edge of SPICLK to the next and is guaranteed to be valid during the rising edge of SPICLK. The uPSD33xx will sample received data on the appropriate edge of SPICLK as determined by SPO. The effect of the SPO Bit can be seen in Figure 43. and Figure 44., page 114. The FLSB Bit in SPICON0 determines the bit order while transmitting and receiving the 8-bit data. When FLSB is '0,' the 8-bit data is transferred in order from MSB (first) to LSB (last). When FLSB Bit is set to '1,' the data is transferred in order from LSB (first) to MSB (last). The clock signal generated on SPICLK is derived from the internal PERIPH_CLK signal. PERIPH_CLK always operates at the frequency, fOSC, and runs constantly except when stopped in MCU Power Down mode. SPICLK is a result of dividing PERIPH_CLK by a sum of different divisors selected by the value contained in the SPICLKD register. The default value in SPICLKD after a reset divides PERIPH_CLK by a factor of 4. The bits in SPICLKD can be set to provide resulting divisor values in of sums of multiples of 4, such as 4, 8, 12, 16, 20, all the way up to 252. For example, if SPICLKD contains 0x24, SPICLK has the frequency of PERIH_CLK divided by 36 decimal. The SPICLK frequency must be set low enough to allow the MCU time to read received data bytes without loosing data. This is dependent upon many things, including the crystal frequency of the MCU and the efficiency of the SPI firmware. Dynamic Control At runtime, bits in registers SPICON0, SPICON1, and SPISTAT are managed by firmware for dynamic control over the SPI interface. The bits Transmitter Enable (TE) and Receiver Enable (RE) when set will allow transmitting and receiving respectively. If TE is disabled, both transmitting and receiving are disabled because SPICLK is driven to constant output logic ‘0’ (when SPO = 0) or logic '1' (when SPO = 1). When the SSEL Bit is set, the SPISEL pin will drive to logic '0' (active) to select a connected slave device at the appropriate time before the first data bit of a byte is transmitted, and SPISEL will automatically return to logic '1' (inactive) after transmitting the eight bit of data, as shown in Figure 44., page 114. SPISEL will continue to automatically toggle this way for each byte data transmission while the SSEL bit is set by firmware. When the SSEL Bit is cleared, the SPISEL pin will drive to constant logic '1' and stay that way (after a transmission in progress completes). The Interrupt Enable Bits (TEIE, RORIE,TIE, and RIE) when set, will allow an SPI interrupt to be generated to the MCU upon the occurrence of the condition enabled by these bits. Firmware must read the four corresponding flags in the SPISTAT register to determine the specific cause of interrupt. These flags are automatically cleared when firmware reads the SPISTAT register.117/231 uPSD33xx Table 59. SPICON0: Control Register 0 (SFR D6h, Reset Value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – TE RE SPIEN SSEL FLSB SBO – Details Bit Symbol R/W Definition 7 – – Reserved 6 TE RW Transmitter Enable 0 = Transmitter is disabled 1 = Transmitter is enabled 5 RE RW Receiver Enable 0 = Receiver is disabled 1 = Receiver is enabled 4 SPIEN RW SPI Enable 0 = Entire SPI Interface is disabled 1 = Entire SPI Interface is enabled 3 SSEL RW Slave Selection 0 = SPISEL output pin is constant logic '1' (slave device not selected) 1 = SPISEL output pin is logic '0' (slave device is selected) during data transfers 2 FLSB RW First LSB 0 = Transfer the most significant bit (MSB) first 1 = Transfer the least significant bit (LSB) first 1 SPO – Sampling Polarity 0 = Sample transfer data at the falling edge of clock (SPICLK is '0' when idle) 1 = Sample transfer data at the rising edge of clock (SPICLK is '1' when idle) 0 – – ReserveduPSD33xx 118/231 Table 60. SPICON1: SPI Interface Control Register 1 (SFR D7h, Reset Value 00h) Table 61. SPICLKD: SPI Prescaler (Clock Divider) Register (SFR D2h, Reset Value 04h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – – – TEIE RORIE TIE RIE Details Bit Symbol R/W Definition 7-4 – – Reserved 3 TEIE RW Transmission End Interrupt Enable 0 = Disable Interrupt for Transmission End 1 = Enable Interrupt for Transmission End 2 RORIE RW Receive Overrun Interrupt Enable 0 = Disable Interrupt for Receive Overrun 1 = Enable Interrupt for Receive Overrun 1 TIE RW Transmission Interrupt Enable 0 = Disable Interrupt for SPITDR empty 1 = Enable Interrupt for SPITDR empty 0 RIE RW Reception Interrupt Enable 0 = Disable Interrupt for SPIRDR full 1 = Enable Interrupt for SPIRDR full Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 DIV128 DIV64 DIV32 DIV16 DIV8 DIV4 – – Details Bit Symbol R/W Definition 7 DIV128 RW 0 = No division 1 = Divide fOSC clock by 128 6 DIV64 RW 0 = No division 1 = Divide fOSC clock by 64 5 DIV32 RW 0 = No division 1 = Divide fOSC clock by 32 4 DIV16 RW 0 = No division 1 = Divide fOSC clock by 16 3 DIV8 RW 0 = No division 1 = Divide fOSC clock by 8 2 DIV4 RW 0 = No division 1 = Divide fOSC clock by 4 1-0 Not Used –119/231 uPSD33xx Table 62. SPISTAT: SPI Interface Status Register (SFR D3h, Reset Value 02h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – – BUSY TEISF RORISF TISF RISF Details Bit Symbol R/W Definition 7-5 – – Reserved 4 BUSY R SPI Busy 0 = Transmit or Receive is completed 1 = Transmit or Receive is in process 3 TEISF R Transmission End Interrupt Source flag 0 = Automatically resets to '0' when firmware reads this register 1 = Automatically sets to '1' when transmission end occurs 2 RORISF R Receive Overrun Interrupt Source flag 0 = Automatically resets to '0' when firmware reads this register 1 = Automatically sets to '1' when receive overrun occurs 1 TISF R Transfer Interrupt Source flag 0 = Automatically resets to '0' when SPITDR is full (just after the SPITDR is written) 1 = Automatically sets to '1' when SPITDR is empty (just after byte loads from SPITDR into SPI shift register) 0 RISF R Receive Interrupt Source flag 0 = Automatically resets to '0' when SPIRDR is empty (after the SPIRDR is read) 1 = Automatically sets to '1' when SPIRDR is fulluPSD33xx 120/231 ANALOG-TO-DIGITAL CONVERTOR (ADC) The ADC unit in the uPSD33xx is a SAR type ADC with an SAR register, an auto-zero comparator and three internal DACs. The unit has 8 input channels with 10-bit resolution. The A/D converter has its own VREF input (80-pin package only), which specifies the voltage reference for the A/D operations. The analog to digital converter (A/D) allows conversion of an analog input to a corresponding 10-bit digital value. The A/D module has eight analog inputs (P1.0 through P1.7) to an 8x1 multiplexor. One ADC channel is selected by the bits in the configuration register. The converter generates a 10-bits result via successive approximation. The analog supply voltage is connected to the VREF input, which powers the resistance ladder in the A/D module. The A/D module has 3 registers, the control register ACON, the A/D result register ADAT0, and the second A/D result register ADAT1. The ADAT0 Register stores Bits 0.. 7 of the converter output, Bits 8.. 9 are stored in Bits 0..1 of the ADAT1 Register. The ACON Register controls the operation of the A/D converter module. Three of the bits in the ACON Register select the analog channel inputs, and the remaining bits control the converter operation. ADC channel pin input is enabled by setting the corresponding bit in the P1SFS0 and P1SFS1 Registers to '1' and the channel select bits in the ACON Register. The ADC reference clock (ADCCLK) is generated from fOSC divided by the divider in the ADCPS Register. The ADC operates within a range of 2 to 16MHz, with typical ADCCLK frequency at 8MHz. The conversion time is 4µs typical at 8MHz. The processing of conversion starts when the Start Bit ADST is set to '1.' After one cycle, it is cleared by hardware. The ADC is monotonic with no missing codes. Measurement is by continuous conversion of the analog input. The ADAT Register contains the results of the A/D conversion. When conversion is complete, the result is loaded into the ADAT. The A/D Conversion Status Bit ADSF is set to '1.' The block diagram of the A/D module is shown in Figure 46. The A/D status bit ADSF is set automatically when A/D conversion is completed and cleared when A/D conversion is in process. In addition, the ADC unit sets the interrupt flag in the ACON Register after a conversion is complete (if AINTEN is set to '1'). The ADC interrupts the CPU when the enable bit AINTEN is set. Port 1 ADC Channel Selects The P1SFS0 and P1SFS1 Registers control the selection of the Port 1 pin functions. When the P1SFS0 Bit is '0,' the pin functions as a GPIO. When bits are set to '1,' the pins are configured as alternate functions. A new P1SFS1 Register selects which of the alternate functions is enabled. The ADC channel is enabled when the bit in P1SFS1 is set to '1.' Note: In the 52-pin package, there is no individual VREF pin because VREF is combined with AVCC pin. Figure 46. 10-Bit ADC ANALOG MUX SELECT ADC OUT - 10 BITS ACON REG ADAT 0 REG CONTROL 10-BIT SAR ADC ADAT1 REG ADC0 ADC1 ADC2 ADC3 ADC4 ADC5 ADC6 ADC7 AVREF P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 AVREF AI07856121/231 uPSD33xx Table 63. ACON Register (SFR 97h, Reset Value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 AINTF AINTEN ADEN ADS2 ADS1 ADS0 ADST ADSF Details Bit Symbol Function 7 AINTF ADC Interrupt flag. This bit must be cleared with software. 0 = No interrupt request 1 = The AINTF flag is set when ADSF goes from '0' to '1.' Interrupts CPU when both AINTF and AINTEN are set to '1.' 6 AINTEN ADC Interrupt Enable 0 = ADC interrupt is disabled 1 = ADC interrupt is enabled 5 ADEN ADC Enable Bit 0 = ADC shut off and consumes no operating current 1 = Enable ADC. After ADC is enabled, 16ms of calibration is needed before ADST Bit is set. 4.. 2 ADS2.. 0 Analog channel Select 000 Select channel 0 (P1.0) 001 Select channel 0 (P1.1) 010 Select channel 0 (P1.2) 011 Select channel 0 (P1.3) 101 Select channel 0 (P1.5) 110 Select channel 0 (P1.6) 111 Select channel 0 (P1.7) 1 ADST ADC Start Bit 0 = Force to zero 1 = Start ADC, then after one cycle, the bit is cleared to '0.' 0 ADSF ADC Status Bit 0 = ADC conversion is not completed 1 = ADC conversion is completed. The bit can also be cleared with software.uPSD33xx 122/231 Table 64. ADCPS Register Details (SFR 94h, Reset Value 00h) Table 65. ADAT0 Register (SFR 95H, Reset Value 00h) Table 66. ADAT1 Register (SFR 96h, Reset Value 00h) Bit Symbol Function 7:4 – Reserved 3 ADCCE ADC Conversion Reference Clock Enable 0 = ADC reference clock is disabled (default) 1 = ADC reference clock is enabled 2:0 ADCPS[2:0] ADC Reference Clock PreScaler Only three Prescaler values are allowed: ADCPS[2:0] = 0, for fOSC frequency 16MHz or less. Resulting ADC clock is fOSC. ADCPS[2:0] = 1, for fOSC frequency 32MHz or less. Resulting ADC clock is fOSC/2. ADCPS[2:0] = 2, for fOSC frequency 32MHz > 40MHz. Resulting ADC clock is fOSC/4. Bit Symbol Function 7:0 – Store ADC output, Bit 7 - 0 Bit Symbol Function 7:2 – Reserved 1.. 0 – Store ADC output, Bit 9, 8123/231 uPSD33xx PROGRAMMABLE COUNTER ARRAY (PCA) WITH PWM There are two Programmable Counter Array blocks (PCA0 and PCA1) in the uPSD33xx. A PCA block consists of a 16-bit up-counter, which is shared by three TCM (Timer Counter Module). A TCM can be programmed to perform one of the following four functions: 1. Capture Mode: capture counter values by external input signals 2. Timer Mode 3. Toggle Output Mode 4. PWM Mode: fixed frequency (8-bit or 16-bit), programmable frequency (8-bit only) PCA Block The 16-bit Up-Counter in the PCA block is a freerunning counter (except in PWM Mode with programmable frequency). The Counter has a choice of clock input: from an external pin, Timer 0 Overflow, or PCA Clock. A PCA block has 3 Timer Counter Modules (TCM) which share the 16-bit Counter output. The TCM can be configured to capture or compare counter value, generate a toggling output, or PWM functions. Except for the PWM function, the other TCM functions can generate an interrupt when an event occurs. Every TCM is connected to a port pin in Port 4; the TCM pin can be configured as an event input, a PWMs, a Toggle Output, or as External Clock Input. The pins are general I/O pins when not assigned to the TCM. The TCM operation is configured by Control registers and Capture/Compare registers. Table 67., page 124 lists the SFR registers in the PCA blocks. Figure 47. PCA0 Block Diagram TIMER0 OVERFLOW P4.3/ECI PCACH0 8-bit PCACL0 8-bit CLKSEL1 IDLE MODE (From CPU) OVF0 INT EOVFI TCM0 TCM1 TCM2 PWM FREQ COMPARE P4.0/CEX0 P4.1/CEX1 P4.2/CEX2 16-bit up Timer/Counter CLKSEL0 PCAIDLE PCA0CLK CLEAR COUNTER EN_PCA EN_ALL AI07857uPSD33xx 124/231 Table 67. PCA0 and PCA1 Registers SFR Address Register Name RW Register Function PCA0 PCA1 PCA0 PCA1 A2 BA PCACL0 PCACL1 RW The low 8 bits of PCA 16-bit counter. A3 BB PCACH0 PCACH1 RW The high 8 bits of PCA 16-bit counter. A4 BC PCACON0 PCACON1 RW Control Register – Enable PCA, Timer Overflow flag , PCA Idle Mode, and Select clock source. A5 A5 PCASTA N/A RW Status Register, Interrupt Status flags – Common for both PCA Block 0 and 1. A9, AA, AB BD, BE, BF TCMMODE0 TCMMODE1 TCMMODE2 TCMMODE3 TCMMODE4 TCMMODE5 RW TCM Mode – Capture, Compare, and Toggle Enable Interrupts – PWM Mode Select. AC AD C1 C2 CAPCOML0 CAPCOMH0 CAPCOML3 CAPCOMH3 RW Capture/Compare registers of TCM0 AF B1 C3 C4 CAPCOML1 CAPCOMH1 CAPCOML4 CAPCOMH4 RW Capture/Compare registers of TCM1 B2 B3 C5 C6 CAPCOML2 CAPCOMH2 CAPCOML5 CAPCOMH5 RW Capture/Compare registers of TCM2 B4 C7 PWMF0 PWMF1 RW The 8-bit register to program the PWM frequency. This register is used for programmable, 8-bit PWM Mode only. FB FC CCON2 CCON3 RW Specify the pre-scaler value of PCA0 or PCA1 clock input125/231 uPSD33xx PCA Clock Selection The clock input to the 16-bit up counter in the PCA block is user-programmable. The three clock sources are: – PCA Prescaler Clock (PCA0CLK, PCA1CLK) – Timer 0 Overflow – External Clock, Pin P4.3 or P4.7 The clock source is selected in the configuration register PCACON. The Prescaler output clock PCACLK is the fOSC divided by the divisor which is specified in the CCON2 or CCON3 Register. When External Clock is selected, the maximum clock frequency should not exceed fOSC/4. Table 68. CCON2 Register Bit Definition (SFR 0FBh, Reset Value 10h) Table 69. CCON3 Register Bit Definition (SFR 0FCh, Reset Value 10h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – – PCA0CE PCA0PS3 PCA0PS2 PCA0PS1 PCA0PS0 Details Bit Symbol R/W Definition 4 PCA0CE R/W PCA0 Clock Enable 0 = PCA0CLK is disabled 1 = PCA0CLK is enabled (default) 3:0 PCA0PS [3:0] R/W PCA0 Prescaler fPCA0CLK = fOSC / (2 ^ PCA0PS[3:0]) Divisor range: 1, 2, 4, 8, 16... 16384, 32768 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – – – PCA1CE PCA1PS3 PCA1PS2 PCA1PS1 PCA1PS0 Details Bit Symbol R/W Definition 4 PCA1CE R/W PCA1 Clock Enable 0 = PCA1CLK is disabled 1 = PCA1CLK is enabled (default) 3:0 PCA1PS [3:0] R/W PCA1 Prescaler fPCA1CLK = fOSC / (2 ^ PCA1PS[3:0]) Divisor range: 1, 2, 4, 8, 16... 16384, 32768uPSD33xx 126/231 Operation of TCM Modes Each of the TCM in a PCA block supports four modes of operation. However, an exception is when the TCM is configured in PWM Mode with programmable frequency. In this mode, all TCM in a PCA block must be configured in the same mode or left to be not used. Capture Mode The CAPCOM registers in the TCM are loaded with the counter values when an external pin input changes state. The user can configure the counter value to be loaded by positive edge, negative edge or any transition of the input signal. At loading, the TCM can generate an interrupt if it is enabled. Timer Mode The TCM modules can be configured as software timers by enable the comparator. The user writes a value to the CAPCOM registers, which is then compared with the 16-bit counter. If there is a match, an interrupt can be generated to CPU. Toggle Mode In this mode, the user writes a value to the TCM's CAPCOM registers and enables the comparator. When there is a match with the Counter output, the output of the TCM pin toggles. This mode is a simple extension of the Timer Mode. PWM Mode - (X8), Fixed Frequency In this mode, one or all the TCM's can be configured to have a fixed frequency PWM output on the port pins. The PWM frequency depends on when the low byte of the Counter overflows (modulo 256). The duty cycle of each TCM module can be specified in the CAPCOMHn Register. When the PCA_Counter_L value is equal to or greater than the value in CAPCOMHn, the PWM output is switched to a high state. When the PCA_Counter_L Register overflows, the content in CAPCOMHn is loaded to CAPCOMLn and a new PWM pulse starts. Figure 48. Timer Mode Note: m = 0: n = 0, 1, or 2 m = 1: n = 3, 4, or 5 MATCH_TIMER INTR 0 0 0 TCMMODEn ENABLE 8 8 MATCH PCASTA CAPCOMLn PCACHm PCACLm 16-bit COMPARATOR CAPCOMHn INTFn 0 0 16-bit up Timer/Counter 8 8 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM1 PWM0 RESET WRITE to CAPCOMHn WRITE to CAPCOMLn 1 0 EN_FLAG C D AI07858127/231 uPSD33xx Figure 49. PWM Mode - (X8), Fixed Frequency Note: m = 0: n = 0, 1, or 2 m = 1: n = 3, 4, or 5 CAPCOMHn OVERFLOW ENABLE 8 PCACLm 8 CAPCOMLn 8-bit COMPARATORn CEXn MATCH S R Q Q SET CLR 0 0 TCMMODEn 0 0 0 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM1 PWM0 AI07859uPSD33xx 128/231 PWM Mode - (X8), Programmable Frequency In this mode, the PWM frequency is not determined by the overflow of the low byte of the Counter. Instead, the frequency is determined by the PWMFm Register. The user can load a value in the PWMFm Register, which is then compared to the low byte of the Counter. If there is a match, the Counter is cleared and the Load registers (PWMFm, CAPCOMHn) are re-loaded for the next PWM pulse. There is only one PWMFm Register which serves all 3 TCM in a PCA block. If one of the TCM modules is operating in this mode, the other modules in the PCA must be configured to the same mode or left not to be used. The duty cycle of the PWM can be specified in the CAPCOMHn Register as in the PWM with fixed frequency mode. Different TCM modules can have their own duty cycle. Note: The value in the Frequency Register (PWMFm) must be larger than the duty cycle register (CAPCOM). Figure 50. PWM Mode - (X8) Programmable Frequency Note: m = 0: n = 0, 1, or 2 m = 1: n = 3, 4, or 5 CLR PCACHm PWM FREQ COMPARE PWMFm = PCACLm PCACLm CAPCOMHn ENABLE ENABLE CEXn 8 8 PWMFm 8-bit COMPARATORm 8-bit COMPARATORn CAPCOMLn MATCH S R Q Q SET CLR 8 0 0 TCMMODEn 0 0 0 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM1 PWM0 AI07860129/231 uPSD33xx PWM Mode - Fixed Frequency, 16-bit The operation of the 16-bit PWM is the same as the 8-bit PWM with fixed frequency. In this mode, one or all the TCM can be configured to have a fixed frequency PWM output on the port pins. The PWM frequency is depending on the clock input frequency to the 16-bit Counter. The duty cycle of each TCM module can be specified in the CAPCOMHn and CAPCOMLn Registers. When the 16- bit PCA_Counter is equal or greater than the values in registers CAPCOMHn and CAPCOMLn, the PWM output is switched to a high state. When the PCA_Counter overflows, CEXn is asserted low. PWM Mode - Fixed Frequency, 10-bit The 10-bit PWM logic requires that all 3 TCMs in PCA0 or PCA1 operate in the same 10-bit PWM mode. The 10-bit PWM operates in a similar manner as the 16-bit PWM, except the PCACHm and PCACLm counters are reconfigured as 10-bit counters. The CAPCOMHn and CAPCOMLn Registers become 10-bit registers. PWM duty cycle of each TCM module can be specified in the 10-bit CAPCOMHn and CAPCOMLn Registers. When the 10-bit PCA counter is equal or greater than the values in the 10-bit registers CAPCOMHn and CAPCOMLn, the PWM output switches to a high state. When the 10-bit PCA counter overflows, the PWM pin is switched to a logic low and starts the next PWM pulse. The most-significant 6 bits in the PCACHm counter and CAPCOMH Register are “Don’t cares” and have no effect on the PWM generation. Writing to Capture/Compare Registers When writing a 16-bit value to the PCA Capture/ Compare registers, the low byte should always be written first. Writing to CAPCOMLn clears the E_COMP Bit to '0'; writing to CAPCOMHn sets E_COMP to '1' the largest duty cycle is 100% (CAPCOMHn CAPCOMLn = 0x0000), and the smallest duty cycle is 0.0015% (CAPCOMHn CAPCOMLn = 0xFFFF). A 0% duty cycle may be generated by clearing the E_COMP Bit to ‘0’. Control Register Bit Definition Each PCA has its own PCA_CONFIGn, and each module within the PCA block has its own TCM_Mode Register which defines the operation of that module (see Table 70., page 129 through Table 71., page 130). There is one PCA_STATUS Register that covers both PCA0 and PCA1 (see Table 72., page 131). Table 70. PCA0 Control Register PCACON0 (SFR 0A4h, Reset Value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 EN-ALL EN_PCA EOVFI PCAIDLE – – CLK_SEL[1:0] Details Bit Symbol Function 7 EN-ALL 0 = No impact on TCM modules 1 = Enable both PCA counters simultaneously (override the EN_PCA Bits) This bit is to start the two 16-bit counters in the PCA. For customers who want 5 PWM, for example, this bit can start all of the PWM outputs. 6 EN_PCA 0 = PCA counter is disabled 1 = PCA counter is enabled EN_PCA Counter Run Control Bit. Set with software to turn the PCA counter on. Must be cleared with software to turn the PCA counter off. 5 EOVFI 1 = Enable Counter Overflow Interrupt if overflow flag (OVF) is set 4 PCAIDLE 0 = PCA operates when CPU is in Idle Mode 1 = PCA stops running when CPU is in Idle Mode 3 – Reserved 2 10B_PWM 0 = Select 16-bit PWM 1 = Select 10-bit PWM 1-0 CLK_SEL [1:0] 00 Select Prescaler clock as Counter clock 01 Select Timer 0 Overflow 10 Select External Clock pin (P4.3 for PCA0) (MAX clock rate = fOSC/4)uPSD33xx 130/231 Table 71. PCA1 Control Register PCACON1 (SFR 0BCh, Reset Value 00h) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 – EN_PCA EOVFI PCAIDLE – – CLK_SEL[1:0] Details Bit Symbol Function 6 EN_PCA 0 = PCA counter is disabled 1 = PCA counter is enabled EN_PCA Counter Run Control Bit. Set with software to turn the PCA counter on. Must be cleared with software to turn the PCA counter off. 5 EOVFI 1 = Enable Counter Overflow Interrupt if overflow flag (OVF) is set 4 PCAIDLE 0 = PCA operates when CPU is in Idle Mode 1 = PCA stops running when CPU is in Idle Mode 3 – Reserved 2 10B_PWM 0 = Select 16-bit PWM 1 = Select 10-bit PWM 1-0 CLK_SEL [1:0] 00 Select Prescaler clock as Counter clock 01 Select Timer 0 Overflow 10 Select External Clock pin (P4.7 for PCA1) (MAX clock rate = fOSC/4)131/231 uPSD33xx Table 72. PCA Status Register PCASTA (SFR 0A5h, Reset Value 00h)uPSD33xx 132/231 TCM Interrupts There are 8 TCM interrupts: 6 match or capture interrupts and two counter overflow interrupts. The 8 interrupts are “ORed” as one PCA interrupt to the CPU. By the nature of PCA application, it is unlikely that many of the interrupts occur simultaneously. If they do, the CPU has to read the interrupt flags and determine which one to serve. The software has to clear the interrupt flag in the Status Register after serving the interrupt. Table 73. TCMMODE0 - TCMMODE5 (6 Registers, Reset Value 00h) Table 74. TCMMODE Register Configurations Note: 1. 10-bit PWM mode requires the 10B_PWM Bit in the PCACON Register set to '1.' Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM[1:0] Details Bit Symbol Function 7 EINTF 1 - Enable the interrupt flags (INTF) in the Status Register to generate an interrupt. 6 E_COMP 1 - Enable the comparator when set 5 CAP_PE 1 - Enable Capture Mode, a positive edge on the CEXn pin. 4 CAP_NE 1 - Enable Capture Mode, a negative edge on the CEXn pin. 3 MATCH 1 - A match from the comparator sets the INTF bits in the Status Register. 2 TOGGLE 1 - A match on the comparator results in a toggling output on CEXn pin. 1-0 PWM[1:0] 01 Enable PWM Mode (x8), fixed frequency. Enable the CEXn pin as a PWM output. 10 Enable PWM Mode (x8) with programmable frequency. Enable the CEXn pin as a PWM output. 11 Enable PWM Mode (x10 or x16), fixed frequency. Enable the CEXn pin as a PWM output. EINTF E_COMP CAP_PE CAP_NE MATCH TOGGLE PWM1 PWM0 TCM FUNCTION 0 0 0 0 0 0 0 0 No operation (reset value) 0 1 0 0 0 0 0 1 8-bit PWM, fixed frequency 0 1 0 0 0 0 10 8-bit PWM, programmable frequency 0 1 0 0 0 0 11 10-bit or 16-bit PMW, fixed frequency(1) X 1 0 0 1 1 0 0 16-bit toggle X 1 0 0 1 0 0 0 16-bit Software Timer X X 0 1 0 0 0 0 16-bit capture, negative trigger X X 1 0 0 0 0 0 16-bit capture, positive trigger X X 1 1 0 0 0 0 16-bit capture, transition trigger133/231 uPSD33xx PSD MODULE The PSD Module is stacked with the MCU Module to form the uPSD33xx, see uPSD33xx HARDWARE DESCRIPTION, page 13. Details of the PSD Module are shown in Figure 51. The two separate modules interface with each other at the 8032 Address, Data, and Control interface blocks in Figure 51. Figure 51. PSD Module Block Diagram PD1 PD2 PORT D PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 PORT B PB0 PB1 PB2 PB3 PB4 PB5 PB6 PB7 GENERAL PLD 20 INPUT MACROCELLS A B 16 OUTPUT MACROCELLS A B A B A B A B A B A B A B B C B C B C B C B C B C B C B C SECURITY LOCK PLD INPUT BUS PIN FEEDBACK NODE FEEDBACK PSD Module: uPSD33XX DECODE PLD AND-OR ARRAY FS0-7 AAAAAAAA BBBBBBBB C C C C TO PLD INPUT BUS PORT C PC0 PC1 PC2 PC3 PC4 PC5 PC6 PC7 JTAG-ISP TO ALL AREAS OF PSD MODULE ADDR, DATA, CONTROL BUS LINKED TO 8032 MCU RUNTIME CONTROL, 256 REGs GPIO, VM, PAGE POWER MNGMT CSIOP PLD CSBOOT0-3 EXTERNAL CHIPSELECTS MAIN FLASH MEMORY Up to 8 SEGMENTS FS0 Up to 256 KBytes TOTAL FS7 2nd FLASH MEMORY Up to 4 SEGMENTS Up to 32 KBytes TOTAL CSBOOT0 CSBOOT3 DATA ADDRESS LATCH LOW ADDR HIGH ADDR 8032 MUX ADDR/DATA AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 8032 HI ADDR A8 A9 A10 A11 A12 A13 A14 A15 8032 CNTL RD WR PSEN ALE RST 8032 MCU Module PORT A (80-pin only) TO JTAG DEBUG ON MCU GPIO PLD GPIO GPIO GPIO 8 PIN INPUTS MCU READ or WRITE MCU READ PLD OUT PLD OUT PLD OUT PLD OUT PLD OUT JTAG CNTL 8 PIN INPUTS 4 PIN INPUTS MCU READ or WRITE RS0 Up to 32 KBytes SRAM PAGE REG JTAG OMC ALLOCATOR AND-OR ARRAY 69 INPUTS 69 INPUTS AI07872B PLD INPUT BUSuPSD33xx 134/231 PSD Module Functional Description Major functional blocks are shown in Figure 51., page 133. The next sections describe each major block. 8032 Address/Data/Control Interface. These signals attach directly to the MCU Module to implement a typical multiplexed 8051-style bus between the two stacked die. The MCU instruction prefetch and branch cache logic resides on the MCU Module, leaving a standard 8051-style memory interface on the PSD Module. The active-low reset signal originating from the MCU Module goes to the PSD Module reset input (RST). This reset signal can then be routed as an external output from the uPSD33xx to the system PC board, if needed, through any one of the PLD output pins as active-high or active-low logic by specifying logic equations in PSDsoft Express. The 8032 address and data busses are routed throughout the PSD Module as shown in Figure 51 connecting many elements on the PSD Module to the 8032 MCU. The 8032 bus is not only connected to the memories, but also to the General PLD, making it possible for the 8032 to directly read and write individual logic macrocells inside the General PLD. Dual Flash Memories and IAP. uPSD33xx devices contain two independent Flash memory arrays. This means that the 8032 can read instructions from one Flash memory array while erasing or writing the other Flash memory array. Concurrent operation like this enables robust remote updates of firmware, also known as In-Application Programming (IAP). IAP can occur using any uPSD33xx interface (e.g., UART, I2C, SPI). Concurrent memory operation also enables the designer to emulate EEPROM memory within either of the two Flash memory arrays for small data sets that have frequent updates. The 8032 can erase Flash memories by individual sectors or it can erase an entire Flash memory array at one time. Each sector in either Flash memory may be individually write protected, blocking any WRITEs from the 8032 (good for boot and start-up code protection). The Flash memories automatically go to standby between 8032 READ or WRITE accesses to conserve power. Minimum erase cycles is 100K and minimum data retention is 15 years. Flash memory, as well as the entire PSD Module may be programmed with the JTAG In-System Programming (ISP) interface with no 8032 involvement, good for manufacturing and lab development. Main Flash Memory. The Main Flash memory is divided into equal sized sectors that are individually selectable by the Decode PLD output signals, named FSx, one signal for each Main Flash memory sector. Each Flash sector can be located at any address within 8032 program address space (accessed with PSEN) or data address space, also known as 8032 XDATA space (accessed with RD or WR), as defined with the software development tool, PSDsoft Express. The user only has to specify an address range for each segment and specify if Main Flash memory will reside in 8032 data or program address space, and then PSEN, RD, or WR are automatically activated for the specified range. 8032 firmware is easily programmed into Main Flash memory using PSDsoft Express or other software tools. See Table 75., page 135 for Main Flash sector sizes on the various uPSD33xx devices. Secondary Flash Memory. The smaller Secondary Flash memory is also divided into equal sized sectors that are individually selectable by the Decode PLD signals, named CSBOOTx, one signal for each Secondary Flash memory sector. Each sector can be located at any address within 8032 program address space (accessed with PSEN) or XDATA space (accessed with RD or WR) as defined with PSDsoft Express. The user only has to specify an address range for each segment, and specify if Secondary Flash memory will reside in 8032 data or program address space, and then PSEN, RD, or WR are automatically activated for the specified range. 8032 firmware is easily programmed into Secondary Flash memory using PSDsoft Express and others. See Table 75., page 135 for Secondary Flash sector sizes. SRAM. The SRAM is selected by a single signal, named RS0, from the Decode PLD. SRAM may be located at any address within 8032 XDATA space (accessed with RD or WR), or optionally within 8032 program address space (accessed with PSEN) to execute code from SRAM. The default setting places SRAM in XDATA space only. These choices are specified using PSDSoft Express, where the user specifies an SRAM address range. The user would also specify (at run-time) if SRAM will additionally reside in 8032 program address space, and then PSEN, RD, or WR are automatically activated for the specified range. See Table 75., page 135 for SRAM sizes. The SRAM may optionally be backed up by an external battery (or other DC source) to make its contents non-volatile (see SRAM Standby Mode (battery backup), page 193).135/231 uPSD33xx Table 75. uPSD33xx Memory Configuration Runtime Control Registers, CSIOP. A block of 256 bytes is decoded inside the PSD Module for module control and status (see Table 79., page 145). The base address of these 256 locations is referred to in this data sheet as csiop (Chip Select I/O Port), and is selected by the Decode PLD output signal, CSIOP. The csiop registers are always viewed by the 8032 as XDATA, and are accessed with RD and WR signals. The address range of CSIOP is specified using PSDsoft Express where the user only has to specify an address range of 256 bytes, and then the RD or WR signals are automatically activated for the specified range. Individual registers within this block are accessed with an offset from the specified csiop base address. 39 registers are used out of the 256 locations to control the output state of I/ O pins, to read I/O pins, to set the memory page, to control 8032 program and data address space, to control power management, to READ/WRITE macrocells inside the General PLD, and other functions during runtime. Unused locations within csiop are reserved and should not be accessed. Memory Page Register. 8032 MCU architecture has an inherent size limit of 64K bytes in either program address space or XDATA space. Some uPSD33xx devices have much more memory that 64K, so special logic such as this page register is needed to access the extra memory. This 8-bit page register (Figure 52) can be loaded and read by the 8032 at runtime as one of the csiop registers. Page register outputs feed directly into both PLDs creating extended address signals used to “page” memory beyond the 64K byte limit (program space or XDATA). Most 8051 compilers directly support memory paging, also known as memory banking. If memory paging is not needed, or if not all eight page register bits are needed for memory paging, the remaining bits may be used in the General PLD for general logic. Page Register outputs are cleared to logic ’0’ at reset and powerup. Programmable Logic (PLDs) . The uPSD33xx contains two PLDs (Figure 63., page 157) that may optionally run in Turbo or Non-Turbo mode. PLDs operate faster (less propagation delay) while in Turbo mode but consume more power than in Non-Turbo mode. Non-Turbo mode allows the PLDs to go to standby automatically when no PLD inputs are changing to conserve power. The logic configuration (from equations) of both PLDs is stored with non-volatile Flash technology and the logic is active upon power-up. PLDs may NOT be programmed by the 8032, PLD programming only occurs through the JTAG interface. Figure 52. Memory Page Register Device Main Flash Memory Secondary Flash Memory SRAM Total Flash Size (bytes) Individual Sector Size (bytes) Number of Sectors (Sector Select Signal) Total Flash Size (bytes) Individual Sector Size (bytes) Number of Sectors (Sector Select Signal) SRAM Size (bytes) uPSD3312 64K 16K 4 (FS0-3) 16K 8K 2 (CSBOOT0-1) 2K uPSD3333 128K 16K 8 (FS0-7) 32K 8K 4 (CSBOOT0-3) 8K uPSD3334 256K 32K 8 (FS0-7) 32K 8K 4 (CSBOOT0-3) 8K uPSD3354 256K 32K 8 (FS0-7) 32K 8K 4 (CSBOOT0-3) 32K 8032 Data Bus Load or Read via csiop + offset E0h D0 D7 D6 D5 D4 D3 D2 D1 Q0 Q7 Q6 Q5 Q4 Q3 Q2 Q1 DPLD and GPLD Page Register ChipSelects and General Logic RST (PSD Module Reset) RST PGR0-7 AI09172uPSD33xx 136/231 PLD #1, Decode PLD (DPLD). This programmable logic implements memory mapping and is used to select one of the individual Main Flash memory segments, one of individual Secondary Flash memory segments, the SRAM, or the group of csiop registers when the 8032 presents an address to DPLD inputs (see Figure 64., page 159). The DPLD can also optionally drive external chip select signals on Port D pins. The DPLD also optionally produces two select signals (PSEL0 and PSEL1) used to enable a special data bus repeater function on Port A, referred to as Peripheral I/O Mode. There are 69 DPLD input signals which include: 8032 address and control signals, Page Register outputs, PSD Module Port pin inputs, and GPLD logic feedback. PLD #2, General PLD (GPLD). This programmable logic is used to create both combinatorial and sequential general purpose logic (see Figure 65., page 161). The GPLD contains 16 Output Macrocells (OMCs) and 20 Input Macrocells (IMCs). Output Macrocell registers are unique in that they have direct connection to the 8032 data bus allowing them to be loaded and read directly by the 8032 at runtime through OMC registers in csiop. This direct access is good for making small peripheral devices (shifters, counters, state machines, etc.) that are accessed directly by the 8032 with little overhead. There are 69 GPLD inputs which include: 8032 address and control signals, Page Register outputs, PSD Module Port pin inputs, and GPLD feedback. OMCs. There are two banks of eight OMCs inside the GPLD, MCELLAB, and MCELLBC, totalling 16 OMCs all together. Each individual OMC is a base logic element consisting of a flip-flop and some AND-OR logic (Figure 66., page 162). The general structure of the GPLD with OMCs is similar in nature to a 22V10 PLD device with the familiar sum-of-products (AND-OR) construct. True and compliment versions of 69 input signals are available to the inputs of a large AND-OR array. ANDOR array outputs feed into an OR gate within each OMC, creating up to 10 product-terms for each OMC. Logic output of the OR gate can be passed on as combinatorial logic or combined with a flipflop within in each OMC to realize sequential logic. OMC outputs can be used as a buried nodes driving internal feedback to the AND-OR array, or OMC outputs can be routed to external pins on Ports A, B, or C through the OMC Allocator. OMC Allocator. The OMC allocator (Figure 67., page 163) will route eight of the OMCs from MCELLAB to pins on either Port A or Port B, and will route eight of the OMCs from MCELLBC to pins on either Port B or Port C, based on what is specified in PSDsoft Express. IMCs. Inputs from pins on Ports A, B, and C are routed to IMCs for conditioning (clocking or latching) as they enter the chip, which is good for sampling and debouncing inputs. Alternatively, IMCs can pass port input signals directly to PLD inputs without clocking or latching (Figure 68., page 167). The 8032 may read the IMCs asynchronously at any time through IMC registers in csiop. Note: The JTAG signals TDO, TDI, TCK, and TMS on Port C do not route through IMCs, but go directly to JTAG logic. I/O Ports. For 80-pin uPSD33xx devices, the PSD Module has 22 individually configurable I/O pins distributed over four ports (these I/O are in addition to I/O on MCU Module). For 52-pin uPSD33xx devices, the PSD Module has 13 individually configurable I/O pins distributed over three ports. See Figure 74., page 181 for I/O port pin availability on these two packages. I/O port pins on the PSD Module (Ports A, B, C, and D) are completely separate from the port pins on the MCU Module (Ports 1, 3, and 4). They even have different electrical characteristics. I/O port pins on the PSD Module are accessed by csiop registers, or they are controlled by PLD equations. Conversely, I/O Port pins on the MCU Module are controlled by the 8032 SFR registers. Table 76. General I/O pins on PSD Module Note: Four pins on Port C are dedicated to JTAG, leaving four pins for general I/O. Pkg Port A Port B Port D Port D Total 52-pin 0 8 4 1 13 80-pin 8 8 4 2 22137/231 uPSD33xx Each I/O pin on the PSD Module can be individually configured for different functions on a pin-bypin basis (Figure 69., page 169). Following are the available functions on PSD Module I/O pins. – MCU I/O: 8032 controls the output state of each port pin or it reads input state of each port pin, by accessing csiop registers at runtime. The direction (in or out) of each pin is also controlled by csiop registers at run-time. – PLD I/O: PSDsoft Express logic equations and pin configuration selections determine if pins are connected to OMC outputs or IMC inputs. This is a static and non-volatile configuration. Port pins connected to PLD outputs can no longer be driven by the 8032 using MCU I/O output mode. – Latched MCU Address Output: Port A or Port B can output de-multiplexed 8032 address signals A0 - A7 on a pin-by-pin basis as specified in csiop registers at run-time. In addition, Port B can also be configured to output de-multiplexed A8-A15 in PSDsoft Express. – Data Bus Repeater: Port A can bidirectionally buffer the 8032 data bus (demultiplexed) for a specified address range in PSDsoft Express. This is referred to as Peripheral I/O Mode in this document. – Open Drain Outputs: Some port pins can function as open-drain as specified in csiop registers at run-time. – Pins on Port D can be used for external chipselect outputs originating from the DPLD, without consuming OMC resources within the GPLD. JTAG Port. In-System Programming (ISP) can be performed through the JTAG signals on Port C. This serial interface allows programming of the entire PSD Module device or subsections of the PSD Module (for example, only Flash memory but not the PLDs) without the participation of the 8032. A blank uPSD33xx device soldered to a circuit board can be completely programmed in 10 to 25 seconds. The four basic JTAG signals on Port C; TMS, TCK, TDI, and TDO form the IEEE-1149.1 interface. The PSD Module does not implement the IEEE-1149.1 Boundary Scan functions, but uses the JTAG interface for ISP an 8032 debug. The PSD Module can reside in a standard JTAG chain with other JTAG devices and it will remain in BYPASS mode when other devices perform JTAG functions. ISP programming time can be reduced as much as 30% by using two optional JTAG signals on Port C, TSTAT and TERR, in addition to TMS, TCK, TDI and TDO, and this is referred to as “6-pin JTAG”. The FlashLINK JTAG programming cable is available from STMicroelectronics and PSDsoft Express software is available at no charge from www.st.com/psm. More JTAG ISP information maybe found in the section titled “JTAG ISP and Debug” on page 137. The MCU module is also included in the JTAG chain within the uPSD33xx device for 8032 debugging and emulation. While debugging, the PSD Module is in BYPASS mode. Conversely, during ISP, the MCU Module is in BYPASS mode. Power Management. The PSD Module has bits in csiop registers that are configured at run-time by the 8032 to reduce power consumption of the GPLD. The Turbo Bit in the PMMR0 Register can be set to logic ’1’ and both PLDs will go to NonTurbo mode, meaning it will latch its outputs and go to sleep until the next transition on its inputs. There is a slight penalty in PLD performance (longer propagation delay), but significant power savings are realized. Going to Non-Turbo mode may require an additional wait state in the 8032 SFR, BUSCON, because memory decode signals are also delayed. The default state of the Turbo Bit is logic '0,' meaning by default, the GPLD is in fast Turbo mode until the Turbo mode is turned off. Additionally, bits in csiop registers PMMR0 and PMMR2 can be set by the 8032 to selectively block signals from entering both PLDs which further reduces power consumption. There is also an Automatic Power Down counter that detects lack of 8032 activity and reduces power consumption on the PSD Module to its lowest level (see Power Management, page 137).uPSD33xx 138/231 Security and NVM Sector Protection. A programmable security bit in the PSD Module protects its contents from unauthorized viewing and copying. The security bit is specified in PSDsoft Express and programmed into the uPSD33xx with JTAG. Once set, the security bit will block access of JTAG programming equipment to the PSD Module Flash memory and PLD configuration, and also blocks JTAG debugging access to the MCU Module. The only way to defeat the security bit is to erase the entire PSD Module using JTAG (the erase command is the only JTAG command allowed after the security bit has been set), after which the device is blank and may be used again. Additionally and independently, the contents of each individual Flash memory sector can be write protected (sector protection) by configuration with PSDsoft Express. This is typically used to protect 8032 boot code from being corrupted by inadvertent WRITEs to Flash memory from the 8032. Status of sector protection bits may be read (but not written) using two registers in csiop space. Memory Mapping There many different ways to place (or map) the address range of PSD Module memory and I/O depending on system requirements. The DPLD provides complete mapping flexibility. Figure 53 shows one possible system memory map. In this example, 128K bytes of Main Flash memory for a uPSD3333 device is in 8032 program address space, and 32K bytes of Secondary Flash memory, the SRAM, and csiop registers are all in 8032 XDATA space. In Figure 53, the nomenclature fs0..fs7 are designators for the individual sectors of Main Flash memory, 16K bytes each. CSBOOT0..CSBOOT3 are designators for the individual Secondary Flash memory segments, 8K bytes each. rs0 is the designator for SRAM, and csiop designates the PSD Module control register set. The designer may easily specify memory mapping in a point-and-click software environment using PSDsoft Express, creating a non-volatile configuration when the DPLD is programmed using JTAG. 8032 Program Address Space. In the example of Figure 53, six sectors of Main Flash memory (fs2.. fs7) are paged across three memory pages in the upper half of program address space, and the remaining two sectors of Main Flash memory (fs0, fs1) reside in the lower half of program address space, and these two sectors are independent of paging (they reside in “common” program address space). This paged memory example is quite common and supported by many 8051 software compilers. 8032 Data Address Space (XDATA). Four sectors of Secondary Flash memory reside in the upper half of 8032 XDATA space in the example of Figure 53. SRAM and csiop registers are in the lower half of XDATA space. The 8032 SFR registers and local SRAM inside the 8032 MCU Module do not reside in XDATA space, so it is OK to place PSD Module SRAM or csiop registers at an address that overlaps the address of internal 8032 MCU Module SRAM and registers. Figure 53. Typical System Memory Map 0000h 8000h A000h C000h E000h FFFFh 8032 XDATA SPACE (RD and WR) 8032 PROGRAM SPACE (PSEN) csboot0 8KB csboot1 8KB csboot2 8KB csboot3 8KB Page X fs0, 16KB Common Memory to All Pages fs7 16KB fs5 16KB fs3 16KB rs0, 8KB Page 0 Page 2 Page 1 2000h 0000h 8000h FFFFh System I/O fs6 16KB fs4 16KB fs2 16KB fs1, 16KB Common Memory to All Pages C000h 4000h csiop 256B AI09173139/231 uPSD33xx Specifying the Memory Map with PSDsoft Express. The memory map example shown in FieuPSD33xx 140/231 EEPROM Emulation. EEPROM emulation is needed if it is desired to repeatedly change only a small number of bytes of data in Flash memory. In this case EEPROM emulation is needed because although Flash memory can be written byte-bybyte, it must be erased sector-by-sector, it is not erasable byte-by-byte (unlike EEPROM which is written AND erased byte-by-byte). So changing one or two bytes in Flash memory typically requires erasing an entire sector each time only one byte is changed within that sector. However, two of the 8K byte sectors of Secondary Flash memory may be used to emulate EEPROM by using a linked-list software technique to create a small data set that is maintained by alternating between the two flash sectors. For example, a data set of 128 bytes is written and maintained by software in a distributed fashion across one 8K byte sector of Secondary Flash memory until it becomes full. Then the writing continues on the other 8K byte sector while erasing the first 8K byte sector. This process repeats continuously, bouncing back and forth between the two 8K byte sectors. This creates a wear-leveling effect, which increases the effective number of erase cycles for a data set of 128 bytes to many times more than the base 100K erase cycles of the Flash memory. EEPROM emulation in Flash memory is typically faster than writing to actual EEPROM memory, and more reliable because the last known value in a data set is maintained even if a WRITE cycle is corrupted by a power outage. The EEPROM emulation function can be called by the firmware, making it appear that the user is writing a single byte, or data record, thus hiding all of the data management that occurs within the two 8K byte flash sectors. EEPROM emulation firmware for the uPSD33xx is available from www.st.com/psm. Alternative Mapping Schemes. Here are more possible memory maps for the uPSD3333. Note: Mapping examples would be slightly different for uPSD3312, uPSD3334, and uPSD3354 because of the different sizes of individual Flash memory sectors and SRAM as defined in Table 82., page 155. – Figure 55. Place the larger Main Flash Memory into program space, but split the Secondary Flash in half, placing two of it’s sectors into XDATA space and remaining two sectors into program space. This method allows the designer to put IAP code (or boot code) into two sectors of Secondary Flash in program space, and use the other two Secondary Flash sectors for data storage, such as EEPROM emulation in XDATA space. – Figure 56. Place both the Main and Secondary Flash memories into program space for maximum code storage, with no Flash memory in XDATA space. Figure 55. Mapping: Split Second Flash in Half Figure 56. Mapping: All Flash in Code Space 0000h 8000h 4000h 6000h FFFFh 8032 XDATA SPACE (RD and WR) 8032 PROGRAM SPACE (PSEN) csboot1, 8KB Common Memory to All Pages csboot0, 8KB Common Memory to All Pages csboot2 8KB csboot3 8KB Page X rs0, 8KB csiop, 256B fs7 16KB fs3 16KB fs1 16KB Page 0 Page 1 Page 2 Page 3 2000h 0000h 8000h FFFFh Nothing Mapped fs6 16KB fs5 16KB fs4 16KB fs2 16KB fs0 16KB System I/O System I/O C000h 2100h 4000h 2000h AI09174 0000h 8000h 4000h 6000h FFFFh 8032 XDATA SPACE (RD and WR) 8032 PROGRAM SPACE (PSEN) csboot1, 8KB Common Memory to All Pages csboot0, 8KB Common Memory to All Pages csboot2, 8KB Common Memory to All Pages csboot3, 8KB Common Memory to All Pages Page X rs0, 8KB csiop, 256B fs7 16KB fs3 16KB fs1 16KB Page 0 Page 1 Page 2 Page 3 2000h 0000h FFFFh fs6 16KB fs5 16KB fs4 16KB fs2 16KB fs0 16KB System I/O C000h 2100h 2000h AI09175141/231 uPSD33xx – Figure 57. Place the larger Main Flash Memory into XDATA space and the smaller Secondary Flash into program space for systems that need a large amount of Flash for data recording or large look-up tables, and not so much Flash for 8032 firmware. Figure 57. Mapping: Small Code / Big Data It is also possible to “reclassify” the Flash memories during runtime, moving the memories between XDATA memory space and program memory space on-the-fly. This essentially means that the user can override the initial setting during run-time by writing to a csiop register (the VM Register). This is useful for IAP, because standard 8051 architecture does not allow writing to program space. For example, if the user wants to update firmware in Main Flash memory that is residing in program space, the user can temporarily “reclassify” the Main Flash memory into XDATA space to erase and rewrite it while executing IAP code from the Secondary Flash memory in program space. After the writing is complete, the Main Flash can be “reclassified” back to program space, then execution can continue from the new code in Main Flash memory. The mapping example of Figure 57 will accommodate this operation. Memory Sector Select Rules. When defining sector select signals (FSx, CSBOOTx, RS0, CSIOP, PSELx) in PSDsoft Express, keep these rules in mind: – Main Flash and Secondary Flash memory sector select signals may not be larger than their physical sector size as defined in Table 75., page 135. – Any Main Flash memory sector select may not be mapped in the same address range as another Main Flash sector select (cannot overlap segments of Main Flash on top of each other). – Any Secondary Flash memory sector select may not be mapped in the same address range as another Secondary Flash sector select (cannot overlap segments of Secondary Flash on top of each other). – A Secondary Flash memory sector may overlap a Main Flash memory sector. In the case of overlap, priority is given to the Secondary Flash memory sector. – SRAM, CSIOP, or PSELx may overlap any Flash memory sector. In the case of overlap, priority is given to SRAM, CSIOP, or PSELx. Note: PSELx is for optional Peripheral I/O Mode on Port A. – The address range for sector selects for SRAM, PSELx, and CSIOP must not overlap each other as they have the same priority, causing contention if overlapped. 0000h 8000h 4000h 6000h FFFFh 8032 XDATA SPACE (RD and WR) 8032 PROGRAM SPACE (PSEN) csboot0 8KB csboot1 8KB csboot2 8KB csboot3 8KB Page X rs0, 8KB Common Memory to All Pages csiop, 256 bytes, Common to All Pages fs7 16KB fs3 16KB fs1 16KB Page 0 Page 1 Page 2 Page 3 2000h 0000h 8000h FFFFh Nothing Mapped fs6 16KB fs5 16KB fs4 16KB fs2 16KB fs0 16KB System I/O C000h 2100h 2000h AI09176uPSD33xx 142/231 Figure 58 illustrates the priority scheme of the memory elements of the PSD Module. Priority refers to which memory will ultimately produce a byte of data or code to the 8032 MCU for a given bus cycle. Any memory on a higher level can overlap and has priority over any memory on a lower level. Memories on the same level must not overlap. Example: FS0 is valid when the 8032 produces an address in the range of 8000h to BFFFh. CSBOOT0 is valid from 8000h to 9FFFh. RS0 is valid from 8000h to 87FFh. Any address from the 8032 in the range of RS0 always accesses the SRAM. Any address in the range of CSBOOT0 greater than 87FFh (and less than 9FFFh) automatically addresses Secondary Flash memory. Any address greater than 9FFFh accesses Main Flash memory. One-half of the Main Flash memory segment, and one-fourth of the Secondary Flash memory segment cannot be accessed by the 8032 in this example. Figure 58. PSD Module Memory Priority The VM Register. One of the csiop registers (the VM Register) controls whether or not the 8032 bus control signals RD, WR, and PSEN are routed to the Main Flash memory, the Secondary Flash memory, or the SRAM. Routing of these signals to these PSM Module memories determines if memories reside in 8032 program address space, 8032 XDATA space, or both. The initial setting of the VM Register is determined by a choice in PSDsoft Express and programmed into the uPSD33xx in a non-volatile fashion using JTAG. This initial setting is loaded into the VM Register upon power-up and also loaded upon any reset event. However, the 8032 may override the initial VM Register setting at run-time by writing to the VM Register, which is useful for IAP. Table 78., page 143 defines bit functions within the VM Register. Note: Bit 7, PIO_EN, is not related to the memory manipulation functions of Bits 0, 1, 2, 3, and 4. Also note that SRAM must at least always be in 8032 XDATA space (default condition). Bit 0 allows the user to optionally place SRAM into 8032 program space in addition to XDATA space. CSIOP registers are always in XDATA space and cannot reside in program space. Figure 59., page 144 illustrates how the VM Register affects the routing of RD, WR, and PSEN to the memories on the PSD Module. As an example, if we apply the value 0Ch to the VM Register to implement the memory map example shown in Figure 53., page 138, then the routing of RD, WR, and PSEN would look like that shown in Figure 60., page 145. In this example, the configuration is specified in PSDsoft Express and programmed into the uPSD33xx using JTAG. Upon power-on or any reset condition, the non-volatile value 0Ch is loaded into the VM Register. At runtime, the value 0Ch in the VM Register may be changed (overridden) by the 8032 if desired to implement IAP or other functions. Level 1 SRAM, CSIOP, and Peripheral I/O Mode Highest Priority Level 2 Secondary Flash Memory Level 3 Main Flash Memory Lowest Priority AI02867E143/231 uPSD33xx Table 78. VM Register (address = csiop + offset E2h) Note: 1. Default value of Bits 0, 1, 2, 3, and 4 is loaded from Non-Volatile setting as specified from PSDsoft Express upon any reset or powerup condition. The default value of these bits can be overridden by 8032 at run-time. 2. Default value of Bit 7 is zero upon any reset condition. Bit 7 PIO_EN Bit 6 Bit 5 Bit 4 Main Flash XDATA Space Bit 3 Secondary Flash XDATA Space Bit 2 Main Flash Program Space Bit 1 Secondary Flash Program Space Bit 0 SRAM Program Space 0 = disable Peripheral I/O Mode on Port A not used not used 0 = RD or WR cannot access Main Flash 0 = RD or WR cannot access Secondary Flash 0 = PSEN cannot access Main Flash 0 = PSEN cannot access Secondary Flash 0 = PSEN cannot access SRAM 1 = enable Peripheral I/O Mode on Port A not used not used 1 = RD or WR can access Main Flash 1 = RD or WR can access Secondary Flash 1 = PSEN can access Main Flash 1 = PSEN can access Secondary Flash 1 = PSEN can access SRAMuPSD33xx 144/231 Figure 59. VM Register Control of Memories DPLD Main Flash Memory Secondary Flash Memory SRAM CS CS CS FS0 - FS7 CSBOOT0 - CSBOOT3 RS0 WR VM REG BIT 4 VM REG BIT 3145/231 uPSD33xx Figure 60. VM Register Example Corresponding to Memory Map Example of Figure 33 Runtime Control Register Definitions (csiop) The 39 csiop registers are defined in Table 79. The 8032 can access each register by the address offset (specified in Table 79) added to the csiop base address that was specified in PSDsoft Express. Do not write to unused locations within the csiop block of 256 registers, they should remain logic zero. Table 79. CSIOP Registers and their Offsets (in hexadecimal) DPLD Main Flash Memory Secondary Flash Memory SRAM CS CS CS FS0 - FS7 CSBOOT0 - CSBOOT3 RS0 WR OE WR OE WR OE 8032 Address 53 Other PLD Inputs WR PSEN RD VM Register = 0Ch AI02869D Register Name Port A (80-pin) Port B Port C Port D Other Description Link Data In 00h 01h 10h 11h MCU I/O input mode. Read to obtain current logic level of pins on Ports A, B, C, or D. No WRITEs. Table 95., page 172 Control 02h 03h Selects MCUI/O or Latched Address Out mode. Logic 0 = MCU I/O, 1 = 8032 Addr Out. Write to select mode. Read for status. Table 107., page 177 Data Out 04h 05h 12h 13h MCU I/O output mode. Write to set logic level on pins of Ports A, B, C, or D. Read to check status. This register has no effect if a port pin is driven by an OMC output from PLD. Table 99., page 172 Direction 06h 07h 14h 15h MCU I/O mode. Configures port pin as input or output. Write to set direction of port pins. Logic 1 = out, Logic 0 = in. Read to check status. Table 103., page 173 Drive Select 08h 09h 16h 17h Write to configure port pins as either CMOS push-pull or Open Drain on some pins, while selecting high slew rate on other pins. Read to check status. Default output type is CMOS push-pull. Table 109., page 179uPSD33xx 146/231 Input Macrocells 0Ah 0Bh 18h Read to obtain logic state of IMCs. No WRITEs. Table 90., page 167 Enable Out OCh 0Dh 1Ah 1Bh Read state of output enable logic on each I/O port driver. 1 = driver output is enabled, 0 = driver is off, and it is in high impedance state. No WRITEs. Table 113., page 180 Output Macrocells AB (MCELLAB) 20h Read logic state of MCELLAB outputs (bank of eight OMCs). Write to load MCELLAB flip-flops. Table 86., page 165 Output Macrocells BC (MCELLBC) 21h Read logic state of MCELLBC outputs (bank of eight OMCs). Write to load MCELLBC flip-flops. Table 87., page 165 Mask Macrocells AB 22h Write to set mask for MCELLAB. Logic '1' blocks READs/WRITEs of OMC. Logic '0' will pass OMC value. Read to check status. Table 88., page 166 Mask Macrocells BC 23h Write to set mask for MCELLBC. Logic '1' blocks READs/WRITEs of OMC. Logic '0' will pass OMC value. Read to check status. Table 89., page 166 Main Flash Sector Protection C0h Read to determine Main Flash Sector Protection Setting (non-volatile) that was specified in PSDsoft Express. No WRITEs. Table 82., page 155 Security Bit and Secondary Flash Sector Protection C2h Read to determine if PSD Module device Security Bit is active (nonvolatile) Logic 1 = device secured. Also read to determine Secondary Flash Protection Setting (non-volatile) that was specified in PSDsoft. No WRITEs. Table 83., page 155 PMMR0 B0h Power Management Register 0. WRITE and READ. Table 117., page 188 PMMR2 B4h Power Management Register 2. WRITE and READ. Table 118., page 188 PMMR3 C7h Power Management Register 3. WRITE and READ. However, Bit 1 can be cleared only by a reset condition. Table 119., page 188 Page E0h Memory Page Register. WRITE and READ. Figure 52., page 135 VM (Virtual Memory) E2h Places PSD Module memories into 8032 Program Address Space and/or 8032 XDATA Address Space. (VM overrides initial non-volatile setting that was specified in PSDsoft Express. Reset restores initial setting) Table 78., page 143 Register Name Port A (80-pin) Port B Port C Port D Other Description Link147/231 uPSD33xx PSD Module Detailed Operation Specific details are given here for the following key functional areas on the PSD Module: ■ Flash Memories ■ PLDs (DPLD and GPLD) ■ I/O Ports ■ Power Management ■ JTAG ISP and Debug Interface Flash Memory Operation. The Flash memories are accessed through the 8032 Address, Data, and Control Bus interfaces. Flash memories (and SRAM) cannot be accessed by any other bus master other than the 8032 MCU (these are not dual-port memories). The 8032 cannot write to Flash memory as it would an SRAM (supply address, supply data, supply WR strobe, assume the data was correctly written to memory). Flash memory must first be “unlocked” with a special instruction sequence of byte WRITE operations to invoke an internal algorithm inside either Flash memory array, then a single data byte is written (programmed) to the Flash memory array, then programming status is checked by a byte READ operation or by checking the Ready/Busy pin (PC3). Table 80., page 148 lists all of the special instruction sequences to program a byte to either of the Flash memory arrays, erase the arrays, and check for different types of status from the arrays. This unlocking sequence is typical for many Flash memories to prevent accidental WRITEs by errant code. However, it is possible to bypass this unlocking sequence to save time while intentionally programming Flash memory. IMPORTANT: The 8032 may not read and execute code from the same Flash memory array for which it is directing an instruction sequence. Or more simply stated, the 8032 may not read code from the same Flash array that is writing or erasing. Instead, the 8032 must execute code from an alternate memory (like SRAM or a different Flash array) while sending instruction sequences to a given Flash array. Since the two Flash memory arrays inside the PSD Module device are completely independent, the 8032 may read code from one array while sending instructions to the other. It is possible, however, to suspend a sector erase operation in one particular Flash array in order to access a different sector within that same Flash array, then resume the erase later. After a Flash memory array is programmed or erased it will go to “Read Array” mode, then the 8032 can read from Flash memory just as it would read from any 8-bit ROM or SRAM device. Flash Memory Instruction Sequences. An instruction sequence consists of a sequence of specific byte WRITE and byte READ operations. Each byte written to either Flash memory array on the PSD Module is received by a state machine inside the Flash array and sequentially decoded to execute an embedded algorithm. The algorithm is executed when the correct number of bytes are properly received and the time between two consecutive bytes is shorter than the time-out period of 80µs. Some instruction sequences are structured to include READ operations after the initial WRITE operations. An instruction sequence must be followed exactly. Any invalid combination of instruction bytes or time-out between two consecutive bytes while addressing Flash memory resets the PSD Module Flash logic into Read Array mode (where Flash memory is read like a ROM device). The Flash memories support instruction sequences summarized in Table 80., page 148. ■ Program a Byte ■ Unlock Sequence Bypass ■ Erase memory by array or by sector ■ Suspend or resume a sector erase ■ Reset to Read Array mode The first two bytes of an instruction sequence are 8032 bus WRITE operations to “unlock” the Flash array, followed by writing a command byte. The bus operations consist of writing the data AAh to address X555h during the first bus cycle and data 55h to address XAAAh during the second bus cycle. 8032 address signals A12-A15 are “Don’t care” during the instruction sequence during WRITE cycles. However, the appropriate sector select signal (FSx or CSBOOTx) from the DPLD must be active during the entire instruction sequence to complete the entire 8032 address (this includes the page number when memory paging is used). Ignoring A12-A15 means the user has more flexibility in memory mapping. For example, in many traditional Flash memories, instruction sequences must be written to addresses AAAAh and 5555h, not XAAAh and X555h like supported on the PSD Module. When AAAAh and 5555h must be written to, the memory mapping options are limited. The Main Flash and Secondary Flash memories each have the same instruction set shown in Table 80., page 148, but the sector select signals determine which memory array will receive and execute the instructions.uPSD33xx 148/231 Table 80. Flash Memory Instruction Sequences(1,2) Instr. Sequence Bus Cycle 1 Bus Cycle 2 Bus Cycle 3 Bus Cycle 4 Bus Cycle 5 Bus Cycle 6 Bus Cycle 7 Link Read Memory Contents (Read Array mode) Read byte from any valid Flash memory addr Read Memory Contents., p age 149 Program (write) a Byte to Flash Memory Write AAh to X555h (unlock) Write 55h to XAAAh (unlock) Write A0h to X555h (command ) Write data byte to address Programmin g Flash Memory., pa ge 150 Bypass Unlock Write AAh to X555h (unlock) Write 55h to XAAAh (unlock) Write 20h to X555h (command ) Bypassed Unlock Sequence, p age 153 Program a Byte to Flash Memory with Bypassed Unlock Write A0h to XXXXh (command) Write data byte to address Bypassed Unlock Sequence, p age 153 Reset Bypass Unlock Write 90h to XXXXh (command) Write 00h to XXXXh (command ) Bypassed Unlock Sequence, p age 153 Flash Bulk Erase(3) Write AAh to X555h (unlock) Write 55h to XAAAh (unlock) Write 80h to X555h (command ) Write AAh to X555h (unlock) Write 55h to XAAAh (unlock) Write 10h to X555h (command) Flash Bulk Erase., page 153 Flash Sector Erase Write AAh to X555h (unlock) Write 55h to XAAAh (unlock) Write 80h to X555h (command ) Write AAh to X555h (unlock) Write 55h to XAAAh (unlock) Write 30h to desired Sector (command) Write 30h to another Sector (command) Flash Sector Erase., page 154 Suspend Sector Erase Write B0h to address that activates FSx or CSBOOTx where erase is in progress (command) Suspend Sector Erase., page 154 Resume Sector Erase Write 30h to address that activates FSx or CSBOOTx where desired to resume erase (command) Resume Sector Erase., page 154149/231 uPSD33xx Note: 1. All values are in hexadecimal, X = Don’t care 2. 8032 addresses A12 through A15 are “Don’t care” during the instruction sequence decoding. Only address bits A0-A11 are used during decoding of Flash memory instruction sequences. The individual sector select signal (FS0 - FS7 or CSBOOT0-CSBOOT3) which is active during the instruction sequence determines the complete address. 3. Directing this command to any individual sector within a Flash memory array will invoke the bulk erase of all Flash memory sectors within that array. Reading Flash Memory. Under typical conditions, the 8032 may read the Flash memory using READ operations (READ bus cycles) just as it would a ROM or RAM device. Alternately, the 8032 may use READ operations to obtain status information about a Program or Erase operation that is currently in progress. The following sections describe the kinds of READ operations. Read Memory Contents. Flash memory is placed in the Read Array mode after Power-up, after a PSD Module reset event, or after receiving a Reset Flash memory instruction sequence from the 8032. The 8032 can read Flash memory contents using standard READ bus cycles anytime the Flash array is in Read Array mode. Flash memories will always be in Read Array mode when the array is not actively engaged in a program or erase operation. Reading the Erase/Program Status Bits. The Flash arrays provide several status bits to be used by the 8032 to confirm the completion of an erase or program operation on Flash memory, shown in Table 81., page 150. The status bits can be read as many times as needed until an operation is complete. The 8032 performs a READ operation to obtain these status bits while an erase or program operation is being executed by the state machine inside each Flash memory array. Data Polling Flag (DQ7). While programming either Flash memory, the 8032 may read the Data Polling Flag Bit (DQ7), which outputs the com1.24Is0.6(2(i)8.4(3(n)]TJl)8.1(e21.5(n)-23.8(0.9(m3.5o)-23.8(f.9(m3.5)-7.23659 16.9(p)D72(g)-0)]TJ 8as)-77.236 of77.236 0.9(m3.h)-23.8(e16.9(6.5(-77.236e21.5([(at).8(r)2-23.8(g21.5([i)-16.2(l)8)17.4(o)-36e21.5(d)24.4(o)]TJ -1-9.097623.8(r)21.5(-77.236o21.5([-1.08TD 0.00)-23.56-6.8(h )236e21.5(8(h )236o21.5(r.9(6.5(..9(m3.5Onc9(6.5(e21.5([)-7.23659 i)-16.2(l)8)17 as)-6.5(e))-23.8(ro9(o)0.1p)-24.3(o)-24.2(f)14.9(08)]TJ 0 b)-8op)-23.6( on )2p.3(as3(eded124.4(F)t)9.5(ee)-23.6(m)9.5(e)D1(i)c)177(o)0.8(0.8(m)- equaat)-8. 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Error Flag (DQ5). During a normal program or erase operation, the Error Flag Bit (DQ5) is to ’0’. This bit is set to ’1’ when there is a failure during Flash memory byte program, sector erase, or bulk erase operations. In the case of Flash memory programming, DQ5 Bit indicates an attempt to program a Flash memory bit from the programmed state of 0, to the erased state of 1, which is not valid. DQ5 may also indicate a particular Flash cell is damaged and cannot be programmed. In case of an error in a Flash memory sector erase or byte program operation, the Flash memory sector in which the error occurred or to which the programmed byte belongs must no longer be used. Other Flash memory sectors may still be used. DQ5 is reset after a Reset Flash instruction sequence. Erase Time-out Flag (DQ3). The Erase Timeout Flag Bit (DQ3) reflects the time-out period allowed between two consecutive sector erase instruction sequence bytes. If multiple sector erase commands are desired, the additional sector erase commands (30h) must be sent by the 8032 within 80us after the previous sector erase command. DQ3 is 0 before this time period has expired, indicating it is OK to issue additional sector erase commands. DQ3 will go to logic ’1’ if the time has been longer than 80µs since the previous sector erase command (time has expired), indication that is not OK to send another sector erase command. In this case, the 8032 must start a new sector erase instruction sequence (unlock and command) beginning again after the current sector erase operation has completed. Programming Flash Memory. When a byte of Flash memory is programmed, individual bits are programmed to logic '0.' The user cannot program a bit in Flash memory to a logic ’1’ once it has been programmed to a logic '0.' A bit must be erased to logic ’1’, and programmed to logic '0.' That means Flash memory must be erased prior to being programmed. A byte of Flash memory is erased to all 1s (FFh). The 8032 may erase the entire Flash memory array all at once, or erase individual sector-by-sector, but not erase byte-by-byte. However, even though the Flash memories cannot be erased byte-by-byte, the 8032 may program Flash memory byte-by-byte. This means the 8032 does not need to program group of bytes (64, 128, etc.) at one time, like some Flash memories. Each Flash memory requires the 8032 to send an instruction sequence to program a byte or to erase sectors (see Table 80., page 148). If the byte to be programmed is in a protected Flash memory sector, the instruction sequence is ignored. IMPORTANT: It is mandatory that a chip-select signal is active for the Flash sector where a programming instruction sequence is targeted. Make sure that the correct chip-select equation, FSx, or CSBOOTx specified in PSDsoft Express matches the address range that the 8032 firmware is accessing, otherwise the instruction sequence will not be recognized by the Flash array. If memory paging is used, be sure that the 8032 firmware sets the page register to the correct page number before issuing an instruction sequence to the Flash memory segment on a particular memory page, otherwise the correct sector select signal will not become active. Once the 8032 issues a Flash memory program or erase instruction sequence, it must check the status bits for completion. The embedded algorithms that are invoked inside a Flash memory array provide several ways to give status to the 8032. Status may be checked using any of three methods: Data Polling, Data Toggle, or Ready/Busy (pin PC3). Table 81. Flash Memory Status Bit Definition Note: 1. X = Not guaranteed value, can be read either '1' or '0.' 2. DQ7-DQ0 represent the 8032 Data Bus Bits, D7-D0. Functional Block FSx, or CSBOOTx DQ7 DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0 Flash Memory Active (the desired segment is selected) Data Polling Toggle Flag Error Flag X Erase Timeout XXX151/231 uPSD33xx Data Polling. Polling on the Data Polling Flag Bit (DQ7) is a method of checking whether a program or erase operation is in progress or has completed. Figure 61 shows the Data Polling algorithm. When the 8032 issues a program instruction sequence, the embedded algorithm within the Flash memory array begins. The 8032 then reads the location of the byte to be programmed in Flash memory to check status. The Data Polling Flag Bit (DQ7) of this location becomes the compliment of Bit D7 of the original data byte to be programmed. The 8032 continues to poll this location, comparing the Data Polling Flag Bit (DQ7) and monitoring the Error Flag Bit (DQ5). When the Data Polling Flag Bit (DQ7) matches Bit D7 of the original data, then the embedded algorithm is complete. If the Error Flag Bit (DQ5) is '1,' the 8032 should test the Data Polling Flag Bit (DQ7) again since the Data Polling Flag Bit (DQ7) may have changed simultaneously with the Error Flag Bit (DQ5) (see Figure 61). The Error Flag Bit (DQ5) is set if either an internal time-out occurred while the embedded algorithm attempted to program the byte (indicating a bad Flash cell) or if the 8032 attempted to program bit to logic ’1’ when that bit was already programmed to logic ’0’ (must erase to achieve logic ’1’). It is suggested (as with all Flash memories) to read the location again after the embedded programming algorithm has completed, to compare the byte that was written to the Flash memory with the byte that was intended to be written. When using the Data Polling method during an erase operation, Figure 61 still applies. However, the Data Polling Flag Bit (DQ7) is '0' until the erase operation is complete. A ’1’ on the Error Flag Bit (DQ5) indicates a time-out condition on the Erase cycle, a ’0’ indicates no error. The 8032 can read any location within the sector being erased to get the Data Polling Flag Bit (DQ7) and the Error Flag Bit (DQ5). PSDsoft Express generates ANSI C code functions for implementation of these Data Polling algorithms. Figure 61. Data Polling Flowchart READ DQ5 & DQ7 at VALID ADDRESS START READ DQ7 FAIL PASS AI01369B DQ7 = DATA YES NO YES NO DQ5 = 1 DQ7 = DATA YES NOuPSD33xx 152/231 Data Toggle. Checking the Toggle Flag Bit (DQ6) is another method of determining whether a program or erase operation is in progress or has completed. Figure 62 shows the Data Toggle algorithm. When the 8032 issues a program instruction sequence, the embedded algorithm within the Flash memory array begins. The 8032 then reads the location of the byte to be programmed in Flash memory to check status. The Toggle Flag Bit (DQ6) of this location toggles each time the 8032 reads this location until the embedded algorithm is complete. The 8032 continues to read this location, checking the Toggle Flag Bit (DQ6) and monitoring the Error Flag Bit (DQ5). When the Toggle Flag Bit (DQ6) stops toggling (two consecutive reads yield the same value), then the embedded algorithm is complete. If the Error Flag Bit (DQ5) is '1,' the 8032 should test the Toggle Flag Bit (DQ6) again, since the Toggle Flag Bit (DQ6) may have changed simultaneously with the Error Flag Bit (DQ5) (see Figure 62). The Error Flag Bit (DQ5) is set if either an internal time-out occurred while the embedded algorithm attempted to program the byte, or if the 8032 attempted to program bit to logic ’1’ when that bit was already programmed to logic ’0’ (must erase to achieve logic ’1’). It is suggested (as with all Flash memories) to read the location again after the embedded programming algorithm has completed, to compare the byte that was written to Flash memory with the byte that was intended to be written. When using the Data Toggle method during an erase operation, Figure 62 still applies. the Toggle Flag Bit (DQ6) toggles until the erase operation is complete. A ’1’ on the Error Flag Bit (DQ5) indicates a time-out condition on the Erase cycle, a ’0’ indicates no error. The 8032 can read any location within the sector being erased to get the Toggle Flag Bit (DQ6) and the Error Flag Bit (DQ5). PSDsoft Express generates ANSI C code functions for implementation of these Data Toggling algorithms. Figure 62. Data Toggle Flowchart READ DQ5 & DQ6 START READ DQ6 FAIL PASS AI01370B DQ6 = TOGGLE NO NO YES YES DQ5 = 1 NO YES DQ6 = TOGGLE153/231 uPSD33xx Ready/Busy (PC3). This signal can be used to output the Ready/Busy status of a program or erase operation on either Flash memory. The output on the Ready/Busy pin is a ’0’ (Busy) when either Flash memory array is being written, or when either Flash memory array is being erased. The output is a ’1’ (Ready) when no program or erase operation is in progress. To activate this function on this pin, the user must select the “Ready/Busy” selection in PSDsoft Express when configuring pin PC3. This pin may be polled by the 8032 or used as a 8032 interrupt to indicate when an erase or program operation is complete (requires routing the signal on PC board from PC3 back into a pin on the MCU Module). This signal is also available internally on the PSD Module as an input to both PLDs (without routing a signal externally on PC board) and it’s signal name is “rd_bsy”. The Ready/Busy output can be probed during lab development to check the timing of Flash memory programming in the system at run-time. Bypassed Unlock Sequence. The Bypass Unlock mode allows the 8032 to program bytes in the Flash memories faster than using the standard Flash program instruction sequences because the typical AAh, 55h unlock bus cycles are bypassed for each byte that is programmed. Bypassing the unlock sequence is typically used when the 8032 is intentionally programming a large number of bytes (such as during IAP). After intentional programming is complete, typically the Bypass mode would be disabled, and full protection is back in place to prevent unwanted WRITEs to Flash memory. The Bypass Unlock mode is entered by first initiating two Unlock bus cycles. This is followed by a third WRITE operation containing the Bypass Unlock command, 20h (as shown in Table 80., page 148). The Flash memory array that received that sequence then enters the Bypass Unlock mode. After this, a two bus cycle program operation is all that is required to program a byte in this mode. The first bus cycle in this shortened program instruction sequence contains the Bypassed Unlocked Program command, A0h, to any valid address within the unlocked Flash array. The second bus cycle contains the address and data of the byte to be programmed. Programming status is checked using toggle, polling, or Ready/Busy just as before. Additional data bytes are programmed the same way until this Bypass Unlock mode is exited. To exit Bypass Unlock mode, the system must issue the Reset Bypass Unlock instruction sequence. The first bus cycle of this instruction must write 90h to any valid address within the unlocked Flash Array; the second bus cycle must write 00h to any valid address within the unlocked Flash Array. After this sequence the Flash returns to Read Array mode. During Bypass Unlock Mode, only the Bypassed Unlock Program instruction, or the Reset Bypass Unlock instruction is valid, other instruction will be ignored. Erasing Flash Memory. Flash memory may be erased sector-by-sector, or an entire Flash memory array may be erased with one command (bulk). Flash Bulk Erase. The Flash Bulk Erase instruction sequence uses six WRITE operations followed by a READ operation of the status register, as described in Table 80., page 148. If any byte of the Bulk Erase instruction sequence is wrong, the Bulk Erase instruction sequence aborts and the device is reset to the Read Array mode. The address provided by the 8032 during the Flash Bulk Erase command sequence may select any one of the eight Flash memory sector select signals FSx or one of the four signals CSBOOTx. An erase of the entire Flash memory array will occur in a particular array even though a command was sent to just one of the individual Flash memory sectors within that array. During a Bulk Erase, the memory status may be checked by reading the Error Flag Bit (DQ5), the Toggle Flag Bit (DQ6), and the Data Polling Flag Bit (DQ7). The Error Flag Bit (DQ5) returns a ’1’ if there has been an erase failure. Details of acquiring the status of the Bulk Erase operation are detailed in the section entitled “Programming Flash Memory., page 150. During a Bulk Erase operation, the Flash memory does not accept any other Flash instruction sequences.uPSD33xx 154/231 Flash Sector Erase. The Sector Erase instruction sequence uses six WRITE operations, as described in Table 80., page 148. Additional Flash Sector Erase commands to other sectors within the same Flash array may be issued by the 8032 if the additional commands are sent within a limited amount of time. The Erase Time-out Flag Bit (DQ3) reflects the time-out period allowed between two consecutive sector erase instruction sequence bytes. If multiple sector erase commands are desired, the additional sector erase commands (30h) must be sent by the 8032 to another sector within 80µs after the previous sector erase command. DQ3 is 0 before this time period has expired, indicating it is OK to issue additional sector erase commands. DQ3 will go to logic ’1’ if the time has been longer than 80µs since the previous sector erase command (time has expired), indicating that is not OK to send another sector erase command. In this case, the 8032 must start a new sector erase instruction sequence (unlock and command), beginning again after the current sector erase operation has completed. During a Sector Erase operation, the memory status may be checked by reading the Error Flag Bit (DQ5), the Toggle Flag Bit (DQ6), and the Data Polling Flag Bit (DQ7), as detailed in Reading the Erase/Program Status Bits, page 149. During a Sector Erase operation, a Flash memory accepts only Reset Flash and Suspend Sector Erase instruction sequences. Erasure of one Flash memory sector may be suspended, in order to read data from another Flash memory sector, and then resumed. The address provided with the initial Flash Sector Erase command sequence (Table 80., page 148) must select the first desired sector (FSx or CSBOOTx) to erase. Subsequent sector erase commands that are appended within the time-out period must be addressed to other desired segments within the same Flash memory array. Suspend Sector Erase. When a Sector Erase operation is in progress, the Suspend Sector Erase instruction sequence can be used to suspend the operation by writing B0h to any valid address within the Flash array that currently is undergoing an erase operation. This allows reading of data from a different Flash memory sector within the same array after the Erase operation has been suspended. Suspend Sector Erase is accepted only during an Erase operation. There is up to 15µs delay after the Suspend Sector Erase command is accepted and the array goes to Read Array mode. The 8032 will monitor the Toggle Flag Bit (DQ6) to determine when the erase operation has halted and Read Array mode is active. If a Suspend Sector Erase instruction sequence was executed, the following rules apply: – Attempting to read from a Flash memory sector that was being erased outputs invalid data. – Reading from a Flash memory sector that was not being erased is valid. – The Flash memory cannot be programmed, and only responds to Resume Sector Erase and Reset Flash instruction sequences. – If a Reset Flash instruction sequence is received, data in the Flash memory sector that was being erased is invalid. Resume Sector Erase. If a Suspend Sector Erase instruction sequence was previously executed, the erase cycle may be resumed with this instruction sequence. The Resume Sector Erase instruction sequence consists of writing the command 30h to any valid address within the Flash array that was suspended as shown in Table 80., page 148. Reset Flash. The Reset Flash instruction sequence resets the embedded algorithm running on the state machine in the targeted Flash memory (Main or Secondary) and the memory goes into Read Array mode. The Reset Flash instruction consists of one bus WRITE cycle as shown in Table 80., page 148, and it must be executed after any error condition that has occurred during a Flash memory Program or Erase operation. It may take the Flash memory up to 25µs to complete the Reset cycle. The Reset Flash instruction sequence is ignored when it is issued during a Program or Bulk Erase operation. The Reset Flash instruction sequence aborts any on-going Sector Erase operation and returns the Flash memory to Read Array mode within 25µs. Reset Signal Applied to Flash Memory. Whenever the PSD Module receives a reset signal from the MCU Module, any operation that is occurring in either Flash memory array will be aborted and the array(s) will go to Read Array mode. It may take up to 25µs to abort an operation and achieve Read Array mode. A reset from the MCU Module will result from any of these events: an active signal on the uPSD33xx RESET_IN input pin, a watchdog timer time-out, detection of low VCC, or a JTAG debug channel reset event.155/231 uPSD33xx Flash Memory Sector Protection. Each Flash memory sector can be separately protected against program and erase operations. This mode can be activated (or deactivated) by selecting this feature in PSDsoft Express and then programming through the JTAG Port. Sector protection can be selected for individual sectors, and the 8032 cannot override the protection during run-time. The 8032 can read, but not change, sector protection. Any attempt to program or erase a protected Flash memory sector is ignored. The 8032 may read the contents of a Flash sector even when a sector is protected. Sector protection status is not read using Flash memory instruction sequences, but instead this status is read by the 8032 reading two registers within csiop address space shown in Table 82 and Table 83. Flash Memory Protection During Power-Up. Flash memory WRITE operations are automatically prevented while VDD is ramping up until it rises above VLKO voltage threshold at which time Flash memory WRITE operations are allowed. PSD Module Security Bit. A programmable security bit in the PSD Module protects its contents from unauthorized viewing and copying. The security bit is set using PSDsoft Express and programmed into the PSD Module with JTAG. When set, the security bit will block access of JTAG programming equipment from reading or modifying the PSD Module Flash memory and PLD configuration. The security bit also blocks JTAG access to the MCU Module for debugging. The only way to defeat the security bit is to erase the entire PSD Module using JTAG (erase is the only JTAG operation allowed while security bit is set), after which the device is blank and may be used again. The 8032 MCU will always have access to Flash mem-uPSD33xx 156/231 PLDs. The PSD Module contains two PLDs: the Decode PLD (DPLD), and the General PLD (GPLD), as shown in Figure 63., page 157. Both PLDs are fed by a common PLD input signal bus, and additionally, the GPLD is connected to the 8032 data bus. PLD logic is specified using PSDsoft Express and programmed into the PSD Module using the JTAG ISP channel. PLD logic is non-volatile and available at power-up. PLDs may not be programmed by the 8032. The PLDs have selectable levels of performance and power consumption. The DPLD performs address decoding, and generates select signals for internal and external components, such as memory, registers, and I/O ports. The DPLD can generate External Chip-Select (ECS1-ECS2) signals on Port D. The GPLD can be used for logic functions, such as loadable counters and shift registers, state machines, encoding and decoding logic. These logic functions can be constructed from a combination of 16 Output Macrocells (OMC), 20 Input Macrocells (IMC), and the AND-OR Array. Routing of the 16 OMCs outputs can be divided between pins on three Ports A, B, or C by the OMC Allocator as shown in Figure 67., page 163. Eight of the 16 OMCs that can be routed to pins on Port A or Port B and are named MCELLAB0- MCELLAB7. The other eight OMCs to be routed to pins on Port B or Port C and are named MCELLBC0-MCELLBC7. This routing depends on the pin number assignments that are specified in PSDsoft Express for “PLD Outputs” in the Pin Definition section. OMC outputs can also be routed internally (not to pins) used as buried nodes to create shifters, counters, etc. The AND-OR Array is used to form product terms. These product terms are configured from the logic definitions entered in PSDsoft Express. A PLD Input Bus consisting of 69 signals is connected to both PLDs. Input signals are shown in Table 84, both the true and compliment versions of each of these signals are available at inputs to each PLD. Note: The 8032 data bus, D0 - D7, does not route directly to PLD inputs. Instead, the 8032 data bus has indirect access to the GPLD (not the DPLD) when the 8032 reads and writes the OMC and IMC registers within csiop address space. Turbo Bit and PLDs. The PLDs can minimize power consumption by going to standby after ALL the PLD inputs remain unchanged for an extended time (about 70ns). When the Turbo Bit is set to logic one (Bit 3 of the csiop PMMR0 Register), Turbo mode is turned off and then this automatic standby mode is achieved. Turning off Turbo mode increases propagation delays while reducing power consumption. The default state of the Turbo Bit is logic zero, meaning Turbo mode is on. Additionally, four bits are available in the csiop PMMR0 and PMMR2 Registers to block the 8032 bus control signals (RD, WR, PSEN, ALE) from entering the PLDs. This reduces power consumption and can be used only when these 8032 control signals are not used in PLD logic equations. See Power Management, page 187. Table 84. DPLD and GPLD Inputs Input Source Input Name Number of Signals 8032 Address Bus A0-A15 16 8032 Bus Control Signals PSEN, RD, WR, ALE 4 Reset from MCU Module RESET 1 Power-Down from AutoPower Down Counter PDN 1 PortA Input Macrocells (80-pin devices only) PA0-PA7 8 PortB Input Macrocells PB0-PB7 8 PortC Input Macrocells PC2, PC3, PC4, PC7 4 Port D Inputs (52-pin devices have only PD1) PD1, PD2 2 Page Register PGR0-PGR7 8 Macrocell OMC bank AB Feedback MCELLAB FB0-7 8 Macrocell OMC bank BC Feedback MCELLBC FB0-7 8 Flash memory Status Bit Ready/Busy 1157/231 uPSD33xx Figure 63. DPLD and GPLD GPLD 20 INPUT MACROCELLS PLD INPUT BUS PIN FEEDBACK, PORTS A, B, C NODE FEEDBACK DPLD Main Flash Memory Selects (FSx) AAAAAAAA BBBBBBBB C C C C 69 INPUTS OMC ALLOCATOR 4 or 8 2 or 4 Secondary Flash Memory Selects (CSBOOTx) 1 SRAM Select (RS0) 1 I/O PORT Select (CSIOP) 2 Periperal I/O Mode Range Selects (PSELx) 1 or 2 External Device Chip-Selects (ECSx) 8 8 4 8 8 4 AND-OR ARRAY AND-OR ARRAY 8032 ADDRESS 8032 BUS CONTROL PAGE REGISTER OTHER SIGNALS 16 OUTPUT MACROCELLS PORT A (80-pin only) PORT C PORT B 8032 DATA BUS PIN FEEDBACK, PORT D PORT D 8032 DATA BUS 8 PLD OUT A B A B A B A B A B A B A B A B B C B C B C B C B C B C B C B C 8 PLD OUT 69 INPUTS AI06600AuPSD33xx 158/231 Decode PLD (DPLD). The DPLD (Figure 64., page 159) generates the following memory decode signals: ■ Eight Main Flash memory sector select signals (FS0-FS7) with three product terms each ■ Four Secondary Flash memory sector select signals (CSBOOT0-CSBOOT3) with three product terms each ■ One SRAM select signal (RS0) with two product terms ■ One select signal for the base address of 256 PSD Module device control and status registers (CSIOP) with one product term ■ Two external chip-select output signals for Port D pins, each with one product term (52- pin devices only have one pin on Port D) ■ Two chip-select signals (PSEL0, PSEL1) used to enable the 8032 data bus repeater function (Peripheral I/O mode) for Port A on 80-pin devices. Each has one product term. A product term indicates the logical OR of two or more inputs. For example, three product terms in a DPLD output means the final output signal is capable of representing the logical OR of three different input signals, each input signal representing the logical AND of a combination of the 69 PLD inputs. Using the signal FS0 for example, the user may create a 3-product term chip select signal that is logic true when any one of three different address ranges are true... FS0 = address range 1 OR address range 2 OR address range 3. The phrase “one product term” is a bit misleading, but commonly used in this context. One product term is the logical AND of two or more inputs, with no OR logic involved at all, such as the CSIOP signal in Figure 64., page 159.159/231 uPSD33xx Figure 64. DPLD Logic Array FS0 FS1 FS7 FS6 FS5 FS4 FS3 FS2 MAIN FLASH MEMORY SECTOR SELECTS CSBOOT0 CSBOOT3 CSBOOT2 CSBOOT1 SECONDARY FLASH MEMORY SECTOR SELECTS RS0 SRAM SELECT CSIOP I/O & CONTROL REGISTERS SELECT ECS0 ECS1 EXTERNAL CHIPSELECTS (PORT D) PSEL0 PSEL1 PERIPHERAL I/O MODE RANGE SELECTS 8032 ADDRESS (A0 - A15) 16 4 1 POWER-DOWN INDICATOR (PDN) 1 PIN INPUT PORTS A, B, C (IMCs) 20 PIN INPUT PORT D 2 OMC FEEDBACK (MCELLAB.FB0-7) 8 PAGE REGISTER (PGR0 - PGR7) 8 8 1 OMC FEEDBACK (MCELLBC.FB0-7) PLD INPUT BUS 3 3 3 3 3 3 3 3 3 3 3 3 2 1 1 1 1 1 NUMBER OF PRODUCT TERMS AI06601A PSM MODULE RESET (RST) FLASH MEM PROG STATUS (RDYBSY) 8032 CNTL (RD, WR, PSEN, ALE)uPSD33xx 160/231 General PLD (GPLD). The GPLD is used to create general system logic. Figure 63., page 157 shows the architecture of the entire GPLD, and Figure 65., page 161 shows the relationship between one OMC, one IMC, and one I/O port pin, which is representative of pins on Ports A, B, and C. It is important to understand how these elements work together. A more detailed description will follow for the three major blocks (OMC, IMC, I/ O Port) shown in Figure 65. Figure 65 also shows which csiop registers to access for various PLD and I/O functions. The GPLD contains: ■ 16 Output Macrocells (OMC) ■ 20 Input Macrocells (IMC) ■ OMC Allocator ■ Product Term Allocator inside each OMC ■ AND-OR Array capable of generating up to 137 product terms ■ Three I/O Ports, A, B, and C161/231 uPSD33xx Figure 65. GPLD: One OMC, One IMC, and One I/O Port (typical pin, Port A, B, or C) OUTPUT MACROCELL (OMC) INPUT MACROCELL (IMC) FLIP-FLOP CLOCK GLOBAL CLOCK FLIP-FLOP CLEAR NODE FEEDBACK NATIVE PRODUCT TERMS PRODUCT TERM ALLOCATOR PRODUCT TERMS FROM OTHER OMCs I/O PORT LOGIC PERIPHERAL I/O MODE BIT OUTPUT ENABLE LATCHED 8032 ADDR BIT PSD MODULE PORT PIN 8032 DATA BIT 8032 DATA BIT OUTPUT ENABLE PIN FEEDBACK CLOCK or GATE SIGNAL PLD INPUT BUS OMC OUT ALE TO OTHER I/O PORT LOGIC OMC ALLOCATOR RESET PSD MODULE RESET FROM OTHER MACROCELL ALLOCATOR GLOBAL CLOCK AND-OR ARRAY CLOCK or GATE RESET FLIP-FLOP AND OTHER LOGIC BORROWED PRODUCT TERMS PIN INPUT LATCH OR PASS INPUT SIGNAL 8032 DATA BITS 8032 DATA BITS CSIOP REGISTERS (DATA OUT, DIRECTION CONTROL, DRIVE) M U X OMC OUTPUT FEED BACK DIRECTION CONTROL DATA OUT CSIOP REGISTERS (DATA IN, DATA OUT, DIRECTION, CONTROL, DRIVE, ENABLE) CSIOP REGISTERS (MCELLAB, MCELLBC) READ OMC LOAD OMC CSIOP REGISTERS (IMCA, IMCB, IMCC) READ IMC FLIP-FLOP PRESET PIN INPUT DATA IN 69 INPUTS 8032 RD 8032 RD 8032 RD 8032 WR 8032 WR 8032 ADDRESS, DATA, CONTROL BUS AI06602AuPSD33xx 162/231 Output Macrocell. The GPLD has 16 OMCs. Architecture of one individual OMC is shown in Figure 66. OMCs can be used for internal node feedback (buried registers to build shift registers, etc.), or their outputs may be routed to external port pins. The user can choose any mixture of OMCs used for buried functions and OMCs used to drive port pins. Referring to Figure 66, for each OMC there are native product terms available from the AND-OR Array to form logic, and also borrowed product terms are available (if unused) from other OMCs. The polarity of the final product term output is controlled by the XOR gate. Each OMC can implement sequential logic using the flip-flop element, or combinatorial logic when bypassing the flip-flop as selected by the output multiplexer. An OMC output can drive a port pin through the OMC Allocator, it can also drive the 8032 data bus, and also it can drive a feedback path to the AND-OR Array inputs, all at the same time. The flip-flop in each OMC can be synthesized as a D, T, JK, or SR type in PSDsoft Express. OMC flipflops are specified using PSDsoft Express in the “User Defined Nodes” section of the Design Assistant. Each flip-flop’s clock, preset, and clear inputs may be driven individually from a product term of the AND-OR Array, defined by equations in PSDsoft Express for signals *. c, *.pr, and *.re respectively. The preset and clear inputs on the flip-flops are level activated, active-high logic signals. The clock inputs on the flip-flops are rising-edge logic signals. Optionally, the signal CLKIN (pin PD1) can be used for a common clock source to all OMC flipflops. Each flip-flop is clocked on the rising edge. A common clock is specified in PSDsoft Express by assigning the function “Common Clock Input” for pin PD1 in the Pin Definition section, and then choosing the signal CLKIN when specifying the clock input (*.c) for individual flip-flops in the “User Defined Nodes” section. Figure 66. Detail of a Single OMC D CLR PRE Q MUX MUX M U X M U X PSDsoft PSDsoft OUTPUT MACROCELL (OMC) PT PRESET (.PR) FROM AND-OR ARRAY BORROWED PTs PT CLEAR (.RE) NODE FEEDBACK (.FB) POLARITY SELECT, PSDsoft PT ALLOCATOR, DRAWS FROM LOCAL AND GLOBAL UNUSED PRODUCT TERMS. PSDsoft DICTATES. LENDED PTs DATA BIT FROM 8032 DATA BIT TO 8032 INDICATES MCU WRITE TO PARTICULAR CSIO OMC REGISTER MCU OVERRIDES PT PRESET AND CLR DURING MCU WRITE MCU READ OF PARTICULAR CSIOP OMC REGISTER OMC OUTPUT FROM AND-OR ARRAY TO PLD INPUT BUS FROM AND-OR ARRAY NATIVE PTs ALLOCATED PTs PT CLOCK (.C) FROM AND-OR ARRAY GLOBAL CLOCK (CLKIN) FROM PLD INPUT BUS 8032 ADDRESS, DATA, CONTROL BUS OMC ALLOCATOR O U T PRODUCT TERMS FROM OTHER OMCs AI06617A163/231 uPSD33xx OMC Allocator. Outputs of the 16 OMCs can be routed to a combination of pins on Port A (80-pin devices only), Port B, or Port C as shown in Figure 67. OMCs are routed to port pins automatically after specifying pin numbers in PSDsoft Express. Routing can occur on a bit-by-bit basis, spitting OMC assignment between the ports. However, one OMC can be routed to one only port pin, not both ports. Product Term Allocator. Each OMC has a Product Term Allocator as shown in Figure 66., page 162. PSDsoft Express uses PT Allocators to give and take product terms to and from other OMCs to fit a logic design into the available silicon resources. This happens automatically in PSDsoft Express, but understanding how PT allocation works will help the user if the logic design does not “fit,” in which case the user may try selecting a different pin or different OMC for the logic where more product terms may be available. The following list summarizes how product terms are allocated to each OMC, as shown in Table 85., page 164. – MCELLAB0-MCELLAB7 each have three native product terms and may borrow up to six more – MCELLBC0-MCELLBC3 each have four native product terms and may borrow up to five more – MCELLBC4-MCELLBC7 each have four native product terms and may borrow up to six more. Native product terms come from the AND-OR Array. Each OMC may borrow product terms only from certain other OMCs, if they are not in use. Product term allocation does not add any propagation delay to the logic. The fitter report generated by PSDsoft Express will show any PT allocation that has occurred. If an equation requires more product terms than are available to it through PT allocation, then “external” product terms are required, which consumes other OMCs. This is called product term expansion and also happens automatically in PSDsoft Express as needed. PT expansion causes additional propagation delay because an additional OMC is consumed by the expansion process and it’s output is rerouted (or fed back) into the AND-OR array. The user can examine the fitter report generated by PSDsoft Express to see resulting PT allocation and PT expansion (expansion will have signal names, such as ‘*.fb_0’ or ‘*.fb_1’). PSDsoft Express will always try to fit the logic design first by using PT allocation, and if that is not sufficient then PSDsoft Express will use PT expansion. Product term expansion may occur in the DPLD for complex chip select equations for Flash memory sectors and for SRAM, but this is a rare occurence. If PSDsoft Express does use PT expansion in the DPLD, it results in an approximate 15ns additional propagation delay for that chip select signal, which gives 15ns less time for the memory to respond. Be aware of this and consider adding a wait state to the 8032 bus access (using the SFR named, BUSCON), or lower the 8032 clock frequency to avoid problems with memory access time. Figure 67. OMC Allocator PORT B PINS PORT C PINS PORT A PINS (80-pin pkg only) OMC Bank AB (MCELLAB0-7) OMC Bank BC (MCELLBC0-7) 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 4 3 2 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 ** ** * = Used for JTAG, Pin Not Available to GPLD AI09177uPSD33xx 164/231 Table 85. OMC Port and Data Bit Assignments Note: 1. MCELLAB0-MCELLAB7 can be output to Port A pins only on 80-pin devices. Port A is not available on 52-pin devices 2. Port pins PC0, PC1, PC5, and PC6 are dedicated JTAG pins and are not available as outputs for MCELLBC 0, 1, 5, or 6 OMC Port Assignment(1,2) Native Product Terms from AND-OR Array Maximum Borrowed Product Terms Data Bit on 8032 Data Bus for Loading or Reading OMC MCELLAB0 Port A0 or B0 3 6 D0 MCELLAB1 Port A1 or B1 3 6 D1 MCELLAB2 Port A2 or B2 3 6 D2 MCELLAB3 Port A3 or B3 3 6 D3 MCELLAB4 Port A4 or B4 3 6 D4 MCELLAB5 Port A5 or B5 3 6 D5 MCELLAB6 Port A6 or B6 3 6 D6 MCELLAB7 Port A7 or B7 3 6 D7 MCELLBC0 Port B0 4 5 D0 MCELLBC1 Port B1 4 5 D1 MCELLBC2 Port B or C2 4 5 D2 MCELLBC3 Port B3 or C3 4 5 D3 MCELLBC4 Port B4 or C4 4 6 D4 MCELLBC5 Port B5 4 6 D5 MCELLBC6 Port B6 4 6 D6 MCELLBC7 Port B7 orC7 4 6 D7165/231 uPSD33xx Loading and Reading OMCs. Each of the two OMC groups (eight OMCs each) occupies a byte in csiop space, named MCELLAB and MCELLBC (see Table 86 and Table 87). When the 8032 writes or reads these two OMC registers in csiop it is accessing each of the OMCs through it’s 8-bit data bus, with the bit assignment shown in Table 85., page 164. Sometimes it is important to know the bit assignment when the user builds GPLD logic that is accessed by the 8032. For example, the user may create a 4-bit counter that must be loaded and read by the 8032, so the user must know which nibble in the corresponding csiop OMC register the firmware must access. The fitter report generated by PSDsoft Express will indicate how it assigned the OMCs and data bus bits to the logic. The user can optionally force PSDsoft Express to assign logic to specific OMCs and data bus bits if desired by using the ‘PROPERTY’ statement in PSDsoft Express. Please see the PSDsoft Express User’s Manual for more information on OMC assignments. Loading the OMC flip-flops with data from the 8032 takes priority over the PLD logic functions. As such, the preset, clear, and clock inputs to the flip-flop can be asynchronously overridden when the 8032 writes to the csiop registers to load the individual OMCs. Table 86. Output Macrocell MCELLAB (address = csiop + offset 20h) Note: All bits clear to logic ’0’ at power-on reset, but do not clear after warm reset conditions (non-power-on reset) Table 87. Output Macrocell MCELLBC (address = csiop + offset 21h) Note: All bits clear to logic ’0’ at power-on reset, but do not clear after warm reset conditions (non-power-on reset) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MCELLAB7 MCELLAB6 MCELLAB5 MCELLAB4 MCELLAB3 MCELLAB2 MCELLAB1 MCELLAB0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MCELLBC7 MCELLBC6 MCELLBC5 MCELLBC4 MCELLBC3 MCELLBC2 MCELLBC1 MCELLBC0uPSD33xx 166/231 OMC Mask Registers. There is one OMC Mask Register for each of the two groups of eight OMCs shown in Table 88 and Table 89. The OMC mask registers are used to block loading of data to individual OMCs. The default value for the mask registers is 00h, which allows loading of all OMCs. When a given bit in a mask register is set to a '1,' the 8032 is blocked from writing to the associated OMC flip-flop. For example, suppose that only four of eight OMCs (MCELLAB0-3) are being used for a state machine. The user may not want the 8032 write to all the OMCs in MCELLAB because it would overwrite the state machine registers. Therefore, the user would want to load the mask register for MCELLAB with the value 0Fh before writing OMCs. Table 88. Output Macrocell MCELLAB Mask Register (address = csiop + offset 22h) Note: 1. Default is 00h after any reset condition 2. 1 = block writing to individual macrocell, 0 = allow writing to individual macrocell Table 89. Output Macrocell MCELLBC Mask Register (address = csiop + offset 23h) Note: 1. Default is 00h after any reset condition 2. 1 = block writing to individual macrocell, 0 = allow writing to individual macrocell Input Macrocells. The GPLD has 20 IMCs, one for each pin on Port A (80-pin device only), one for each pin on Port B, and for the four pins on Port C that are not JTAG pins. The architecture of one individual IMC is shown in Figure 68., page 167. IMCs are individually configurable, and they can strobe a signal coming in from a port pin as a latch (gated), or as a register (clocked), or the IMC can pass the signal without strobing, all prior to driving the signal onto the PLD input bus. Strobing is useful for sampling and debouncing inputs (keypad inputs, etc.) before entering the PLD AND-OR arrays. The outputs of IMCs can be read by the 8032 asynchronously when the 8032 reads the csiop registers shown in Table 90, Table 91, and Table 92., page 167. It is possible to read a PSD Module port pin using one of two different methods, one method is by reading IMCs as described here, the other method is using MCU I/O mode described in a later section. The optional IMC clocking or gating signal used to strobe pin inputs is driven by a product term from the AND-OR array. There is one clocking or gating product term available for each group of four IMCs. Port inputs 0-3 are controlled by one product term and 4-7 by another. To specify in PSDsoft Express the method in which a signal will be strobed as it enters an IMC for a given input pin on Port A, B, or C, just specify “PT Clocked Register” to use a rising edge to clock the incoming signal, or specify “PT Clock Latch” to use an active high gate signal to latch the incoming signal. Then define an equation for the IMC clock (.ld) or the IMC gate (.le) signal in the “I/O Equations” section. If the user would like to latch an incoming signal using the gate signal ALE from the 8032, then in PSDsoft Express, for a given input pin on Port A, B, or C, specify “Latched Address” as the pin function. If it is desired to pass an incoming signal through an IMC directly to the AND-OR array inputs without clocking or gating (this is most common), in PSDsoft Express simply specify “Logic or Address” for the input pin function on Port A, B, or C. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Mask MCELLAB7 Mask MCELLAB6 Mask MCELLAB5 Mask MCELLAB4 Mask MCELLAB3 Mask MCELLAB2 Mask MCELLAB1 Mask MCELLAB0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Mask MCELLBC7 Mask MCELLBC6 Mask MCELLBC5 Mask MCELLBC4 Mask MCELLBC3 Mask MCELLBC2 Mask MCELLBC1 Mask MCELLBC0167/231 uPSD33xx Figure 68. Detail of a Single IMC Table 90. Input Macrocell Port A(1) (address = csiop + offset 0Ah) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. 1 = current state of IMC is logic '1,' 0 = current state is logic ’0’ Table 91. Input Macrocell Port B (address = csiop + offset 0Bh) Note: 1 = current state of IMC is logic '1,' 0 = current state is logic ’0’ Table 92. Input Macrocell Port C (address = csiop + offset 18h) Note: 1. X = Not guaranteed value, can be read either '1' or '0.' These are JTAG pins. 2. 1 = current state of IMC is logic '1,' 0 = current state is logic ’0’ Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 IMC PA7 IMC PA6 IMC PA5 IMC PA4 IMC PA3 IMC PA2 IMC PA1 IMC PA0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 IMC PB7 IMC PB6 IMC PB5 IMC PB4 IMC PB3 IMC PB2 IMC PB1 IMC PB0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 IMC PC7 X X IMC PC4 IMC PC3 IMC PC2 X X INPUT MACROCELL (IMC) Q D G Q D M U X M U X PSDsoft 8032 DATA BIT 8032 READ OF PARTICULAR CSIOP IMC REGISTER PT CLOCK OR GATE (.LD OR .LE) PIN INPUT LATCHED INPUT GATED INPUT (.LD) (.LE) ALE PSDsoft ALE 8032 ADDR, DATA, CNTL BUS FROM I/O PORT LOGIC INPUT SIGNAL FROM PIN ON PORT A, B, or C FROM AND-OR ARRAY TO PLD INPUT BUS THIS SIGAL IS GANGED TO 3 OTHER IMCs, GROUPING IMC 0 - 3 or IMC 4 - 7. AI06603AuPSD33xx 168/231 I/O Ports. There are four programmable I/O ports on the PSD Module: Port A (80-pin device only), Port B, Port C, and Port D. Ports A and B are eight bits each, Port C is four bits, and Port D is two bits for 80-pin devices or 1-bit for 52-pin devices. Each port pin is individually configurable, thus allowing multiple functions per port. The ports are configured using PSDsoft Express then programming with JTAG, and also by the 8032 writing to csiop registers at run-time. Topics discussed in this section are: ■ General Port architecture ■ Port Operating Modes ■ Individual Port Structure General Port Architecture. The general architecture for a single I/O Port pin is shown in Figure 69., page 169. Port structures for Ports A, B, C, and D differ slightly and are shown in Figure 74., page 181 though Figure 77., page 186. Figure 69., page 169 shows four csiop registers whose outputs are determined by the value that the 8032 writes to csiop Direction, Drive, Control, and Data Out. The I/O Port logic contains an output mux whose mux select signal is determined by PSDsoft Express and the csiop Control register bits at run-time. Inputs to this output mux include the following: 1. Data from the csiop Data Out register for MCU I/O output mode (All ports) 2. Latched de-multiplexed 8032 Address for Address Output mode (Ports A and B only) 3. Peripheral I/O mode data bit (Port A only) 4. GPLD OMC output (Ports A, B, and C). The Port Data Buffer (PDB) provides feedback to the 8032 and allows only one source at a time to be read when the 8032 reads various csiop registers. There is one PDB for each port pin enabling the 8032 to read the following on a pin-by-pin basis: 1. MCU I/O signal direction setting (csiop Direction reg) 2. Pin drive type setting (csiop Drive Select reg) 3. Latched Addr Out mode setting (csiop Control reg) 4. MCU I/O pin output setting (csiop Data Out reg) 5. Output Enable of pin driver (csiop Enable Out reg) 6. MCU I/O pin input (csiop Data In reg) A port pin’s output enable signal is controlled by a two input OR gate whose inputs come from: a product term of the AND-OR array; the output of the csiop Direction Register. If an output enable from the AND-OR Array is not defined, and the port pin is not defined as an OMC output, and if Peripheral I/O mode is not used, then the csiop Direction Register has sole control of the OE signal. As shown in Figure 69., page 169, a physical port pin is connected to the I/O Port logic and is also separately routed to an IMC, allowing the 8032 to read a port pin by two different methods (MCU I/O input mode or read the IMC). Port Operating Modes. I/O Port logic has several modes of operation. Table 88., page 166 summarizes which modes are available on each port. Each of the port operating modes are described in following sections. Some operating modes can be defined using PSDsoft Express, and some by the 8032 writing to the csiop registers at run-time, and some require both. For example, PLD I/O, Latched Address Out, and Peripheral I/O modes must be defined in PSDsoft Express and programmed into the device using JTAG, but an additional step must happen at run-time to activate Latched Address Out mode and Peripheral I/O mode, but not needed for PLD I/O. In another example, MCU I/O mode is controlled completely by the 8032 at runtime and only a simple pin name declaration is needed in PSDsoft Express for documentation. Table 89., page 166 summarizes what actions are needed in PSDsoft Express and what actions are required by the 8032 at run-time to achieve the various port functions.169/231 uPSD33xx Figure 69. Detail of a Single I/O Port (typical of Ports A, B, C) I/O PORT LOGIC O U T P U T M U X P D B M U X DIRECTION DRIVE SELECT CONTROL DATA OUT (MCUI/O) ENABLE OUT DATA IN (MCUI/O) D BIT, PERIPH I/O MODE, Port A PT OUTPUT ENABLE (.OE) LATCHED ADDR BIT, PORT A or B OE MUX 8032 DATA BIT OUTPUT DRIVER TYPICAL PIN PORT A, B, C PSD MODULE RESET ONE of 6 CSIOP REGISTERS OUTPUT SELECT PERIPHERAL I/O MODE SETS DIRECTION (PORT A ONLY) 8032 ADDRESS, DATA, CONTROL BUS 1 2 3 1 4 2 3 4 5 6 FROM OMC OUTPUT TO IMC FROM PLD INPUT BUS FROM AND-OR ARRAY FROM OMC ALLOCATOR D CLR DIRECTION DRIVE CONTROL (MCUI/O) DATA OUT RESET PSDsoft PSELx PERIPH I/O DATA BIT CSIOP REGISTERS Q Q Q Q 8032 DRIVE TYPE DATA BITS INPUT BUFFER OUTPUT ENABLE WR RD PIO EN 8032 WR 8032 RD AI07873AuPSD33xx 170/231 Table 93. Port Operating Modes Note: 1. MCELLBC outputs available only on pins PC2, PC3, PC4, and PC7. 2. JTAG pins (PC0/TMS, PC1/TCK, PC5/TDI, PC6/TDO) are dedicated to JTAG pin functions (cannot be used for general I/O). Port Operating Mode Port A (80-pin only) Port B Port C Port D Find it MCU I/O Yes Yes Yes Yes MCU I/O Mode., p age 172 PLD I/O OMC MCELLAB Outputs OMC MCELLBC Outputs External Chip-Select Outputs PLD Inputs Yes No No Yes Yes Yes No Yes No Yes(1) No Yes No No Yes Yes PLD I/O Mode., p age 174 Latched Address Output Yes Yes No No Latched Address Output Mode, pa ge 177 Peripheral I/O Mode Yes No No No Peripher al I/O Mode, pa ge 178 JTAG ISP No No Yes(2) No JTAG ISP Mode., p age 179171/231 uPSD33xx Table 94. Port Configuration Setting Requirements Port Operating Mode Required Action in PSDsoft Express to Configure each Pin Value that 8032 writes to csiop Control Register at run-time Value that 8032 writes to csiop Direction Register at run-time Value that 8032 writes to Bit 7 (PIO_EN) of csiop VM Register at run-time MCU I/O Choose the MCU I/O function and declare the pin name Logic '0' (default) Logic 1 = Out of uPSD Logic 0 = Into uPSD N/A PLD I/O Choose the PLD function type, declare pin name, and specify logic equation(s) N/A Direction register has no effect on a pin if pin is driven from OMC output N/A Latched Address Output Choose Latched Address Out function, declare pin name Logic '1' Logic '1' Only N/A Peripheral I/O Choose Peripheral I/O mode function and specify address range in DPLD for PSELx N/A N/A PIO_EN Bit = Logic 1 (default is '0') 4-PIN JTAG ISP No action required in PSDsoft to get 4-pin JTAG. By default TDO, TDI, TCK, TMS are dedicated JTAG functions. N/A N/A N/A 6-PIN JTAG ISP (faster programming) Choose JTAG TSTAT function for pin PC3 and JTAG TERR function for pin PC4. N/A N/A N/AuPSD33xx 172/231 MCU I/O Mode. In MCU I/O mode, the 8032 on the MCU Module expands its own I/O by using the I/O Ports on the PSD Module. The 8032 can read PSD Module I/O pins, set the direction of the I/O pins, and change the output state of I/O pins by accessing the Data In, Direction, and Data Out csiop registers respectively at run-time. To implement MCU I/O mode, each desired pin is specified in PSDsoft Express as MCU I/O function and given a pin name. Then 8032 firmware is written to set the Direction bit for each corresponding pin during initialization routines (0 = In, 1 = Out of the chip), then the 8032 firmware simply reads the corresponding Data In register to determine the state of an I/O pin, or writes to a Data Out register to set the state of a pin. The Direction of each pin may be changed dynamically by the 8032 if desired. A mixture of input and output pins within a single port is allowed. Figure 69., page 169 shows the Data In, Data Out, and Direction signal paths. The Data In registers are defined in Table 95 to Table 98. The Data Out registers are defined in Table 99 to Table 102., page 173. The Direction registers are defined in Table 103 to Table 106., page 173. Table 95. MCU I/O Mode Port A Data In Register(1) (address = csiop + offset 00h) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. For each bit, 1 = current state of input pin is logic '1,' 0 = current state is logic ’0’ Table 96. MCU I/O Mode Port B Data In Register (address = csiop + offset 01h) Note: For each bit, 1 = current state of input pin is logic '1,' 0 = current state is logic ’0’ Table 97. MCU I/O Mode Port C Data In Register (address = csiop + offset 10h) Note: 1. X = Not guaranteed value, can be read either '1' or '0.' 2. For each bit, 1 = current state of input pin is logic '1,' 0 = current state is logic ’0’ Table 98. MCU I/O Mode Port D Data In Register (address = csiop + offset 11h) Note: 1. X = Not guaranteed value, can be read either '1' or '0.' 2. For each bit, 1 = current state of input pin is logic '1,' 0 = current state is logic ’0’ 3. Not available on 52-pin uPSD33xx devices Table 99. MCU I/O Mode Port A Data Out Register(1) (address = csiop + offset 04h) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. For each bit, 1 = drive port pin to logic '1,' 0 = drive port pin to logic ’0’ 3. Default state of register is 00h after reset or power-up Table 100. MCU I/O Mode Port B Data Out Register (address = csiop + offset 05h) Note: 1. For each bit, 1 = drive port pin to logic '1,' 0 = drive port pin to logic ’0’ 2. Default state of register is 00h after reset or power-up Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PC7 X X PC4 PC3 PC2 X X Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 XXXXX PD2(3) PD1 X Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0173/231 uPSD33xx Table 101. MCU I/O Mode Port C Data Out Register (address = csiop + offset 12h) Note: 1. For each bit, 1 = drive port pin to logic '1,' 0 = drive port pin to logic ’0’ 2. Default state of register is 00h after reset or power-up Table 102. MCU I/O Mode Port D Data Out Register (address = csiop + offset 13h) Note: 1. For each bit, 1 = drive port pin to logic '1,' 0 = drive port pin to logic ’0’ 2. Default state for register is 00h after reset or power-up 3. Not available on 52-pin uPSD33xx devices Table 103. MCU I/O Mode Port A Direction Register(1) (address = csiop + offset 06h) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. For each bit, 1 = out from uPSD33xx port pin1, 0 = in to PSD33xx port pin 3. Default state for register is 00h after reset or power-up Table 104. MCU I/O Mode Port B Direction In Register (address = csiop + offset 07h) Note: 1. For each bit, 1 = out from uPSD33xx port pin1, 0 = in to PSD33xx port pin 2. Default state for register is 00h after reset or power-up Table 105. MCU I/O Mode Port C Direction Register (address = csiop + offset 14h) Note: 1. For each bit, 1 = out from uPSD33xx port pin1, 0 = in to PSD33xx port pin 2. Default state for register is 00h after reset or power-up Table 106. MCU I/O Mode Port D Direction Register (address = csiop + offset 15h) Note: 1. For each bit, 1 = out from uPSD33xx port pin1, 0 = in to PSD33xx port pin 2. Default state for register is 00h after reset or power-up 3. Not available on 52-pin uPSD33xx devices Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PC7 N/A N/A PC4 PC3 PC2 N/A N/A Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 N/A N/A N/A N/A N/A PD2(3) PD1 N/A Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PC7 N/A N/A PC4 PC3 PC2 N/A N/A Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 N/A N/A N/A N/A N/A PD2(3) PD1 N/AuPSD33xx 174/231 PLD I/O Mode. Pins on Ports A, B, C, and D can serve as inputs to either the DPLD or the GPLD. Inputs to these PLDs from Ports A, B, and C are routed through IMCs before reaching the PLD input bus. Inputs to the PLDs from Port D do not pass through IMCs, but route directly to the PLD input bus. Pins on Ports A, B, and C can serve as outputs from GPLD OMCs, and Port D pins can be outputs from the DPLD (external chip-selects) which do not consume OMCs. Whenever a pin is specified to be a PLD output, it cannot be used for MCU I/O mode, or other pin modes. If a pin is specified to be a PLD input, it is still possible to read the pin using MCU I/O input mode with the csiop register Data In. Also, the csiop Direction register can still affect a pin which is used for a PLD input. The csiop Data Out register has no effect on a PLD output pin. Each pin on Ports A, B, C, and D have a tri-state buffer at the final output stage. The Output Enable signal for this buffer is driven by the logical OR of two signals. One signal is an Output Enable signal generated by the AND-OR array (from an .oe equation specified in PSDsoft), and the other signal is the output of the csiop Direction register. This logic is shown in Figure 69., page 169. At power-on, all port pins default to high-impedance input (Direction registers default to 00h). However, if an equation is written for the Output Enable that is active at power-on, then the pin will behave as an output. PLD I/O equations are specified in PSDsoft Express and programmed into the uPSD using JTAG. Figure 70 shows a very simple combinatorial logic example which is implemented on pins of Port B. To give a general idea how PLD logic is implemented using PSDsoft Express, Figure 71., page 175 illustrates the pin declaration window of PSDsoft Express, showing the PLD output at pin PB0 declared as “Combinatorial” in the “PLD Output” section, and a signal name, “pld_out”, is specified. The other three signals on pins PB1, PB2, and PB3 would be declared as “Logic or Address” in the “PLD Input” section, and given signal names. In the “Design Assistant” window of PSDsoft Express shown in Figure 72., page 176, simply enter the logic equation for the signal “pld_out” as shown. Either type in the logic statements or enter them using a point-and-click method, selecting various signal names and logic operators available in the window. After PSDsoft Express has accepted and realized the logic from the equations, it synthesizes the logic statement: pld_out = ( pld_in_1 # pld_in_2 ) & !pld_in_3; to be programmed into the GPLD. See the PSDsoft User’s Manual for all the steps. Note: If a particular OMC output is specified as an internal node and not specified as a port pin output in PSDsoft Express, then the port pin that is associated with that OMC can be used for other I/O functions. Figure 70. Simple PLD Logic Example PLDIN 1 PLDIN 2 PLDIN 3 PLD OUT PB0 PB3 PB2 PB1 AI09178175/231 uPSD33xx Figure 71. Pin Declarations in PSDsoft Express for Simple PLD ExampleuPSD33xx 176/231 Figure 72. Using the Design Assistant in PSDsoft Express for Simple PLD Example177/231 uPSD33xx Latched Address Output Mode. In the MCU Module, the data bus Bits D0-D15 are multiplexed with the low address Bits A0-A15, and the ALE signal is used to separate them with respect to time. Sometimes it is necessary to send de-multiplexed address signals to external peripherals or memory devices. Latched Address Output mode will drive individual demuxed address signals on pins of Ports A or B. Port pins can be designated for this function on a pin-by-pin basis, meaning that an entire port will not be sacrificed if only a few address signals are needed. To activate this mode, the desired pins on Port A or Port B are designated as “Latched Address Out” in PSDsoft. Then in the 8032 initialization firmware, a logic ’1’ is written to the csiop Control register for Port A or Port B in each bit position that corresponds to the pin of the port driving an address signal. Table 107 and Table 108 define the csiop Control register locations and bit assignments. The latched low address byte A4-A7 is available on both Port A and Port B. The high address byte A8-A15 is available on Port B only. Selection of high or low address byte is specified in PSDsoft Express. Table 107. Latched Address Output, Port A Control Register(1) (address = csiop + offset 02h) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. For each bit, 1 = drive demuxed 8032 address signal on pin, 0 = pin is default mode, MCU I/O 3. Default state for register is 00h after reset or power-up Table 108. Latched Address Output, Port B Control Register (address = csiop + offset 03h) Note: 1. For each bit, 1 = drive demuxed 8032 address signal on pin, 0 = pin is default mode, MCU I/O 2. Default state for register is 00h after reset or power-up Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PA7 (addr A7) PA6 (addr A6) PA5 (addr A5) PA4 (addr A4) PA3 (addr A3) PA2 (Addr A2) PA1 (addr A1) PA0 (addr A0) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PB7 (addr A7 or A15) PB6 (addr A6 or A14) PB5 (addr A5 or A13) PB4 (addr A4 or A12) PB3 (addr A3 or A11) PB2 (Addr A2 or A10) PB1 (addr A1 or A9) PB0 (addr A0 or A8)uPSD33xx 178/231 Peripheral I/O Mode. This mode will provide a data bus repeater function for the 8032 to interface with external parallel peripherals. The mode is only available on Port A (80-pin devices only) and the data bus signals, D0 - D7, are de-multiplexed (no address A0-A7). When active, this mode behaves like a bidirectional buffer, with the direction automatically controlled by the 8032 RD and WR signals for a specified address range. The DPLD signals PSEL0 and PSEL1 determine this address range. Figure 69., page 169 shows the action of Peripheral I/O mode on the Output Enable logic of the tri-state output driver for a single port pin. Figure 73., page 178 illustrates data repeater the operation. To activate this mode, choose the pin function “Peripheral I/O Mode” in PSDsoft Express on any Port A pin (all eight pins of Port A will automatically change to this mode). Next in PSDsoft, specify an address range for the PSELx signals in the “Chip-Select” section of the “Design Assistant.” Specify an address range for either PSEL0 or PSEL1. Always qualify the PSELx equation with “PSEN is logic '1'” to ensure Peripheral I/O mode is only active during 8032 data cycles, not code cycles. Only one equation is needed since PSELx signals are OR’ed together (Figure 73). Then in the 8032 initialization firmware, a logic ’1’ is written to the csiop VM register, Bit 7 (PIO_EN) as shown in Table 73., page 132. After this, Port A will automatically perform this repeater function whenever the 8032 presents an address (and memory page number, if paging is used) that is within the range specified by PSELx. Once Port A is designated as Peripheral I/O mode in PSDsoft Express, it cannot be used for other functions. Note: The user can alternatively connect an external parallel peripheral to the standard 8032 AD0- AD7 pins on an 80-pin uPSD device (not Port A), but these pins have multiplexed address and data signals, with a weaker fanout drive capability. Figure 73. Peripheral I/O Mode PSEL1 PORT A pins PA0 - PA7 PSEL0 VM REGISTER BIT 7 (PIO EN) 8032 RD 8032 WR 8032 DATA BUS D0-D7 (DE-MUXED) 8 8 AI02886A179/231 uPSD33xx JTAG ISP Mode. Four of the pins on Port C are based on the IEEE 1149.1 JTAG specification and are used for In-System Programming (ISP) of the PSD Module and debugging of the 8032 MCU Module. These pins (TDI, TDO, TMS, TCK) are dedicated to JTAG and cannot be used for any other I/O function. There are two optional pins on Port C (TSTAT and TERR) that can be used to reduce programming time during ISP. See JTAG ISP and JTAG Debug, page 195. Other Port Capabilities. It is possible to change the type of output drive on the ports at run-time. It is also possible to read the state of the output enable signal of the output driver at run-time. The following sections provide the details. Port Pin Drive Options. The csiop Drive Select registers allow reconfiguration of the output drive type for certain pins on Ports A, B, C, and D. The 8032 can change the default drive type setting at run-time. The is no action needed in PSDsoft Express to change or define these pin output drive types. Figure 69., page 169 shows the csiop Drive Select register output controlling the pin output driver. The default setting for drive type for all pins on Ports A, B, C, and D is a standard CMOS pushpull output driver. Note: When a pin on Port A, B, C, D is not used as an output and has no external device driving it as an input (floating pin), excess power consumption can be avoided by placing a weak pull-up resistor (100KΩ) to VDD which keeps the CMOS input pin from floating. Drive Select Registers. The csiop Drive Select Registers will configure a pin output driver as Open Drain or CMOS push/pull for some port pins, and controls the slew rate for other port pins. An external pull-up resistor should be used for pins configured as Open Drain, and the resistor should be sized not to exceed the current sink capability of the pin (see DC specifications). Open Drain outputs are diode clamped, thus the maximum voltage on an pin configured as Open Drain is VDD + 0.7V. A pin can be configured as Open Drain if its corresponding bit in the Drive Select Register is set to logic '1.' Note: The slew rate is a measurement of the rise and fall times of an output. A higher slew rate means a faster output response and may create more electrical noise. A pin operates in a high slew rate when the corresponding bit in the Drive Register is set to '1.' The default rate is standard slew rate (see AC specifications). Table 109 through Table 112., page 180 show the csiop Drive Registers for Ports A, B, C, and D. The tables summarize which pins can be configured as Open Drain outputs and which pins the slew rate can be changed. The default output type is CMOS push/pull output with normal slew rate. Enable Out Registers. The state of the output enable signal for the output driver at each pin on Ports A, B, C, and D can be read at any time by the 8032 when it reads the csiop Enable Output registers. Logic '1' means the driver is in output mode, logic ’0’ means the output driver is in high-impedance mode, making the pin suitable for input mode (read by the input buffer shown in Figure 69., page 169). Figure 69 shows the three sources that can control the pin output enable signal: a product term from AND-OR array; the csiop Direction register; or the Peripheral I/O Mode logic (Port A only). The csiop Enable Out registers represent the state of the final output enable signal for each port pin driver, and are defined in Table 113., page 180 through Table 116., page 180. Table 109. Port A Pin Drive Select Register(1) (address = csiop + offset 08h) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. For each bit, 1 = pin drive type is selected, 0 = pin drive type is default mode, CMOS push/pull 3. Default state for register is 00h after reset or power-up Table 110. Port B Pin Drive Select Register (address = csiop + offset 09h) Note: 1. For each bit, 1 = pin drive type is selected, 0 = pin drive type is default mode, CMOS push/pull 2. Default state for register is 00h after reset or power-up Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PA7 Open Drain PA6 Open Drain PA5 Open Drain PA4 Open Drain PA3 Slew Rate PA2 Slew Rate PA1 Slew Rate PA0 Slew Rate Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PB7 Open Drain PB6 Open Drain PB5 Open Drain PB4 Open Drain PB3 Slew Rate PB2 Slew Rate PB1 Slew Rate PB0 Slew RateuPSD33xx 180/231 Table 111. Port C Pin Drive Select Register (address = csiop + offset 16h) Note: 1. For each bit, 1 = pin drive type is selected, 0 = pin drive type is default mode, CMOS push/pull 2. Default state for register is 00h after reset or power-up Table 112. Port D Pin Drive Select Register (address = csiop + offset 17h) Note: 1. For each bit, 1 = pin drive type is selected, 0 = pin drive type is default mode, CMOS push/pull 2. Default state for register is 00h after reset or power-up 3. Pin is not available on 52-pin uPSD33xx devices Table 113. Port A Enable Out Register(1) (address = csiop + offset 0Ch) Note: 1. Port A not available on 52-pin uPSD33xx devices 2. For each bit, 1 = pin drive is enabled as an output, 0 = pin drive is off (high-impedance, pin used as input) Table 114. Port B Enable Out Register (address = csiop + offset 0Dh) Note: For each bit, 1 = pin drive is enabled as an output, 0 = pin drive is off (high-impedance, pin used as input) Table 115. Port C Enable Out Register (address = csiop + offset 1Ah) Note: 1. For each bit, 1 = pin drive is enabled as an output, 0 = pin drive is off (high-impedance, pin used as input) Table 116. Port D Enable Out Register (address = csiop + offset 1Bh) Note: 1. For each bit, 1 = pin drive is enabled as an output, 0 = pin drive is off (high-impedance, pin used as input) 2. Pin is not available on 52-pin uPSD33xx devices Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PC7 Open Drain N/A (JTAG) N/A (JTAG) PC4 Open Drain PC3 Open Drain PC2 Open Drain N/A (JTAG) N/A (JTAG) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 N/A N/A N/A N/A N/A PD2(3) Slew Rate PD1 Slew Rate N/A Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PA7 OE PA6 OE PA5 OE PA4 OE PA3 OE PA2 OE PA1 OE PA0 OE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PB7 OE PB6 OE PB5 OE PB4 OE PB3 OE PB2 OE PB1 OE PB0 OE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PC7 OE N/A (JTAG) N/A (JTAG) PC4 OE PC3 OE PC2 OE N/A (JTAG) N/A (JTAG) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 N/A N/A N/A N/A N/A PD2 OE(2) PD1 OE N/A181/231 uPSD33xx Individual Port Structures. Ports A, B, C, and D have some differences. The structure of each individual port is described in the next sections. Port A Structure. Port A supports the following operating modes: ■ MCU I/O Mode ■ GPLD Output Mode from Output Macrocells MCELLABx ■ GPLD Input Mode to Input Macrocells IMCAx ■ Latched Address Output Mode ■ Peripheral I/O Mode Port A also supports Open Drain/Slew Rate output drive type options using csiop Drive Select registers. Pins PA0-PA3 can be configured to fast slew rate, pins PA4-PA7 can be configured to Open Drain Mode. See Figure 74 for details. Figure 74. Port A Structure Note: 1. Port pins PA0-PA3 are capable of Fast Slew Rate output drive option. Port pins PA4-PA7 are capable of Open Drain output option. I/O PORT A LOGIC O U T P U T M U P X D B M U X DIRECTION DRIVE SELECT CONTROL DATA OUT (MCUI/O) ENABLE OUT DATA IN (MCUI/O) D BIT, PERIPH I/O MODE PT OUTPUT ENABLE (.OE) LATCHED ADDR BIT OE MUX OUTPUT ENABLE TYPICAL PIN, PORT A PSD MODULE RESET ONE of 6 CSIOP REGISTERS OUTPUT SELECT PERIPHERAL I/O MODE SETS DIRECTION 8032 ADDRESS, DATA, CONTROL BUS 1 2 3 1 4 2 3 4 5 6 FROM OMC OUTPUT (MCELLABx) FROM PLD INPUT BUS FROM ANDOR ARRAY FROM OMC ALLOCATOR D CLR DIRECTION DRIVE CONTROL (MCUI/O) DATA OUT 8032 WR RESET PSDsoft 8032 RD WR RD PSELx PERIPH I/O DATA BIT TO IMCs PIO EN CSIOP REGISTERS Q Q Q Q DRIVE TYPE SELECT(1) 8032 DATA BITS 8032 DATA BIT PIN INPUT CMOS BUFFER NO HYSTERESIS VDD VDD PIN OUTPUT 1 = OPEN DRAIN, PA4 - PA7 1 = FAST SLEW RATE, PA0 - PA3 IMCA0 - IMCA7 AI09179uPSD33xx 182/231 Port B Structure. Port B supports the following operating modes: ■ MCU I/O Mode ■ GPLD Output Mode from Output Macrocells MCELLABx, or MCELLBCx (OMC allocator routes these signals) ■ GPLD Input Mode to Input Macrocells IMCBx ■ Latched Address Output Mode Port B also supports Open Drain/Slew Rate output drive type options using the csiop Drive Select registers. Pins PB0-PB3 can be configured to fast slew rate, pins PB4-PB7 can be configured to Open Drain Mode. See Figure 75 for detail. Figure 75. Port B Structure Note: 1. Port pins PB0-PB3 are capable of Fast Slew Rate output drive option. Port pins PB4-PB7 are capable of Open Drain output option. I/O PORT B LOGIC O U T P U T M U P X D B M U X DIRECTION DRIVE SELECT CONTROL DATA OUT (MCUI/O) ENABLE OUT DATA IN (MCUI/O) PT OUTPUT ENABLE (.OE) LATCHED ADDR BIT OUTPUT ENABLE OUTPUT ENABLE TYPICAL PIN, PORT B PSD MODULE RESET ONE of 6 CSIOP REGISTERS OUTPUT SELECT 8032 ADDRESS, DATA, CONTROL BUS 1 2 3 1 2 3 4 5 6 FROM OMC OUTPUT (MCELLABx or MCELLBCx) FROM PLD INPUT BUS FROM ANDOR ARRAY FROM OMC ALLOCATOR D CLR DIRECTION DRIVE CONTROL (MCUI/O) DATA OUT 8032 WR RESET PSDsoft 8032 RD TO IMCs CSIOP REGISTERS Q Q Q Q DRIVE TYPE SELECT(1) 8032 DATA BITS 8032 DATA BIT PIN INPUT CMOS BUFFER NO HYSTERESIS VDD VDD PIN OUTPUT 1 = OPEN DRAIN, PB4 - PB7 1 = FAST SLEW RATE, PB0 - PB3 IMCB0 - IMCB7 AI09180183/231 uPSD33xx Port C Structure. Port C supports the following operating modes on pins PC2, PC3, PC4, PC7: ■ MCU I/O Mode ■ GPLD Output Mode from Output Macrocells MCELLBC2, MCELLBC3, MCELLBC4, MCELLBC7 ■ GPLD Input Mode to Input Macrocells IMCC2, IMCC3, IMCC4, IMCC7 See Figure 76., page 184 for detail. Port C pins can also be configured in PSDsoft for other dedicated functions: – Pins PC3 and PC4 support TSTAT and TERR status indicators, to reduce the amount of time required for JTAG ISP programming. These two pins must be used together for this function, adding to the four standard JTAG signals. When TSTAT and TERR are used, it is referred to as “6-pin JTAG”. PC3 and PC4 cannot be used for other functions if they are used for 6-pin JTAG. See JTAG ISP and JTAG Debug, page 195 for details. – PC2 can be used as a voltage input (from battery or other DC source) to backup the contents of SRAM when VDD is lost. This function is specified in PSDsoft Express as SRAM Standby Mode (battery backup), page 193. – PC3 can be used as an output to indicate when a Flash memory program or erase operation has completed. This is specified in PSDsoft Express as Ready/Busy (PC3), page 153. – PC4 can be used as an output to indicate when the SRAM has switched to backup voltage (when VDD is less than the battery input voltage on PC2). This is specified in PSDsoft Express as “Standby-On Indicator” (see SRAM Standby Mode (battery backup), page 193). The remaining four pins (TDI, TDO, TCK, TMS) on Port C are dedicated to the JTAG function and cannot be used for any other function. See JTAG ISP and JTAG Debug, page 195. Port C also supports the Open Drain output drive type options on pins PC2, PC3, PC4, and PC7 using the csiop Drive Select registers.uPSD33xx 184/231 Figure 76. Port C Structure Note: 1. Pull-up switches to VBAT when SRAM goes to battery back-up mode. 2. Optional function on a specific Port C pin. I/O PORT C LOGIC O U T P U T M U P X D B M U X DIRECTION DRIVE SELECT DATA OUT (MCUI/O) ENABLE OUT DATA IN (MCUI/O) PT OUTPUT ENABLE, .OE (JTAG STATE MACHINE AUTOMATICALLY CONTROLS OE FOR JTAG SIGNALS) OUTPUT ENABLE TYPICAL PIN, PORT C PSD MODULE RESET ONE of 6 CSIOP REGISTERS 8032 ADDRESS, DATA, CONTROL BUS 1 2 3 4 5 1 2 3 4 5 FROM OMC OUTPUT (MCELLBCx) STANDBY ON(2) FROM SRAM BACK-UP CIRCUIT FROM FLASH MEMORIES TO/FROM JTAG STATE MACHINE FROM PLD INPUT BUS FROM ANDOR ARRAY FROM OMC ALLOCATOR D CLR DIRECTION DRIVE (MCUI/O) DATA OUT 8032 WR RESET PSDsoft 8032 RD TO IMCs CSIOP REGISTERS Q Q Q DRIVE TYPE SELECT(2) 8032 DATA BITS 8032 DATA BIT PIN CMOS INPUT BUFFER NO HYSTERESIS VDD VDD/VBAT (1) VDD/VBAT (1) PIN OUTPUT 50k PULL-UP ONLY ON JTAG TDI, TMS, TCK SIGNALS TO SRAM BATTERY BACK-UP CIRCUIT(2) IMCC2, IMCC3, IMCC4, IMCC7 RDY/BSY(2) TDO, TSTAT(2), TERR(2) TDI, TMS, TCK AI09181185/231 uPSD33xx Port D Structure. Port D has two I/O pins (PD1, PD2) on 80-pin uPSD33xx devices, and just one pin (PD1) on 52-pin devices, supporting the following operating modes: ■ MCU I/O Mode ■ DPLD Output Mode for External Chip Selects, ECS1, ECS2. This does not consume OMCs in the GPLD. ■ PLD Input Mode – direct input to the PLD Input Bus available to DPLD and GPLD. Does not use IMCs See Figure 77., page 186 for detail. Port D pins can also be configured in PSDsoft as pins for other dedicated functions: – PD1 can be used as a common clock input to all 16 OMC Flip-flops (see OMCs, page 136) and also the Automatic Power-Down (APD), page 189. – PD2 can be used as a common chip select signal (CSI) for the Flash and SRAM memories on the PSD Module (see Chip Select Input (CSI), page 191). If driven to logic ’1’ by an external source, CSI will force all memories into standby mode regardless of what other internal memory select signals are doing on the PSD Module. This is specified in PSDsoft as “PSD Chip Select Input, CSI”. Port D also supports the Fast Slew Rate output drive type option using the csiop Drive Select registers.uPSD33xx 186/231 Figure 77. Port D Structure Note: 1. Optional function on a specific Port D pin. I/O PORT D LOGIC O U T P U T M U P X D B M U X DIRECTION DRIVE SELECT DATA OUT (MCUI/O) ENABLE OUT DATA IN (MCUI/O) PT OUTPUT ENABLE (.OE) OUTPUT ENABLE OUTPUT ENABLE TYPICAL PIN, PORT D PSD MODULE RESET ONE of 5 CSIOP REGISTERS 8032 ADDRESS, DATA, CONTROL BUS 1 2 1 2 3 4 5 FROM DPLD EXTERNAL CHIP (ECSx) FROM PLD INPUT BUS FROM ANDOR ARRAY FROM DPLD D CLR DIRECTION DRIVE (MCUI/O) DATA OUT 8032 WR RESET PSDsoft 8032 RD TO POWER MANAGEMENT AND PLD INPUT BUS CSIOP REGISTERS Q Q Q 8032 DRIVE TYPE SELECT DATA BITS 8032 DATA BIT PIN INPUT CMOS BUFFER NO HYSTERESIS VDD VDD PIN OUTPUT 1 = FAST SLEW RATE PD1. PIN, PD2.PIN DIRECTLY TO PLD INPUT BUS, NO IMC CSI(1) TO POWER MANAGEMENT CLKIN(1) AI09182187/231 uPSD33xx Power Management. The PSD Module offers configurable power saving options, and also a way to manage power to the SRAM (battery backup). These options may be used individually or in combinations. A top level description for these functions is given here, then more detailed descriptions will follow. – Zero-Power Memory: All memory arrays (Flash and SRAM) in the PSD Module are built with zero-power technology, which puts the memories into standby mode (~ zero DC current) when 8032 address signals are not changing. As soon as a transition occurs on any address input, the affected memory “wakes up”, changes and latches its outputs, then goes back to standby. The designer does not have to do anything special to achieve this memory standby mode when no inputs are changing—it happens automatically. Thus, the slower the 8032 clock, the lower the current consumption. Both PLDs (DPLD and GPLD) are also zeropower, but this is not the default condition. The 8032 must set a bit in one of the csiop PMMR registers at run-time to achieve zero-power. – Automatic Power-Down (APD): The APD feature allows the PSD Module to reach it’s lowest current consumption levels. If enabled, the APD counter will time-out when there is a lack of 8032 bus activity for an extended amount of time (8032 asleep). After time-out occurs, all 8032 address and data buffers on the PSD Module are shut down, preventing the PSD Module memories and potentially the PLDs from waking up from standby, even if address inputs are changing state because of noise or any external components driving the address lines. Since the actual address and data buffers are turned off, current consumption is even further reduced. Note: Non-address signals are still available to PLD inputs and will wake up the PLDs if these signals are changing state, but will not wake up the memories. The APD counter requires a relatively slow external clock input on pin PD1 that does stop when the 8032 goes to sleep mode. – Forced Power-Down (FPD): The MCU can put the PSD Module into Power-Down mode with the same results as using APD described above, but FPD does not rely on the APD counter. Instead, FPD will force the PSD Module into Power-Down mode when the MCU firmware sets a bit in one of the csiop PMMR registers. This is a good alternative to APD because no external clock is needed for the APD counter. – PSD Module Chip Select Input (CSI): This input on pin PD2 (80-pin devices only) can be used to disable the internal memories, placing them in standby mode even if address inputs are changing. This feature does not block any internal signals (the address and data buffers are still on but signals are ignored) and CSI does not disable the PLDs. This is a good alternative to using the APD counter, which requires an external clock on pin PD1. – Non-Turbo Mode: The PLDs can operate in Turbo or non-Turbo modes. Turbo mode has the shortest signal propagation delay, but consumes more current than non-Turbo mode. A csiop register can be written by the 8032 to select modes, the default mode is with Turbo mode enabled. In non-Turbo mode, the PLDs can achieve very low standby current (~ zero DC current) while no PLD inputs are changing, and the PLDs will even use less AC current when inputs do change compared to Turbo mode. When the Turbo mode is enabled, there is a significant DC current component AND the AC current component is higher than non-Turbo mode, as shown in Figure 85., page 202 (5V) and Figure 86., page 202 (3.3V). – Blocking Bits: Significant power savings can be achieved by blocking 8032 bus control signals (RD, WR, PSEN, ALE) from reaching PLD inputs, if these signals are not used in any PLD equations. Blocking is achieved by the 8032 writing to the “blocking bits” in csiop PMMR registers. Current consumption of the PLDs is directly related to the composite frequency of all transitions on PLD inputs, so blocking certain PLD inputs can significantly lower PLD operating frequency and power consumption (resulting in a lower frequency on the graphs of Figure 85., page 202 and Figure 86., page 202). – SRAM Backup Voltage: Pin PC2 can be configured in PSDsoft to accept an alternate DC voltage source (battery) to automatically retain the contents of SRAM when VDD drops below this alternate voltage. Note: It is recommended to prevent unused inputs from floating on Ports A, B, C, and D by pulling them up to VDD with a weak external resistor (100KΩ), or by setting the csiop Direction register to “output” at run-time for all unused inputs. This will prevent the CMOS input buffers of unused input pins from drawing excessive current. The csiop PMMR register definitions are shown in 117 through Table 119., page 188.uPSD33xx 188/231 Table 117. Power Management Mode Register PMMR0 (address = csiop + offset B0h) Note: All the bits of this register are cleared to zero following Power-up. Subsequent Reset (RST) pulses do not clear the registers. 1. Blocking bits should be set to logic ’1’ only if the signal is not needed in a DPLD or GPLD logic equation. Table 118. Power Management Mode Register PMMR2 (address = csiop + offset B4h) Note: The bits of this register are cleared to zero following Power-up. Subsequent Reset (RST) pulses do not clear the registers. 1. Blocking bits should be set to logic ’1’ only if the signal is not needed in a DPLD or GPLD logic equation. Table 119. Power Management Mode Register PMMR3 (address = csiop + offset C7h) Note: The bits of this register are cleared to zero following Power-up. Subsequent Reset (RST) pulses do not clear the registers. Bit 0 X 0 Not used, and should be set to zero. Bit 1 APD Enable 0 Automatic Power Down (APD) counter is disabled. 1 APD counter is enabled Bit 2 X 0 Not used, and should be set to zero. Bit 3 PLD Turbo Disable 0 = on PLD Turbo mode is on 1 = off PLD Turbo mode is off, saving power. Bit 4 Blocking Bit, CLKIN to PLDs(1) 0 = on CLKIN (pin PD1) to the PLD Input Bus is not blocked. Every transition of CLKIN powers-up the PLDs. 1 = off CLKIN input to PLD Input Bus is blocked, saving power. But CLKIN still goes to APD counter. Bit 5 Blocking Bit, CLKIN to OMCs Only(1) 0 = on CLKIN input is not blocked from reaching all OMC’s common clock inputs. 1 = off CLKIN input to common clock of all OMCs is blocked, saving power. But CLKIN still goes to APD counter and all PLD logic besides the common clock input on OMCs. Bit 6 X 0 Not used, and should be set to zero. Bit 7 X 0 Not used, and should be set to zero. Bit 0 X 0 Not used, and should be set to zero. Bit 1 X 0 Not used, and should be set to zero. Bit 2 Blocking Bit, WR to PLDs(1) 0 = on 8032 WR input to the PLD Input Bus is not blocked. 1 = off 8032 WR input to PLD Input Bus is blocked, saving power. Bit 3 Blocking Bit, RD to PLDs(1) 0 = on 8032 RD input to the PLD Input Bus is not blocked. 1 = off 8032 RD input to PLD Input Bus is blocked, saving power. Bit 4 Blocking Bit, PSEN to PLDs(1) 0 = on 8032 PSEN input to the PLD Input Bus is not blocked. 1 = off 8032 PSEN input to PLD Input Bus is blocked, saving power. Bit 5 Blocking Bit, ALE to PLDs(1) 0 = on 8032 ALE input to the PLD Input Bus is not blocked. 1 = off 8032 ALE input to PLD Input Bus is blocked, saving power. Bit 5 Blocking Bit, PC7 to PLDs(1) 0 = on Pin PC7 input to the PLD Input Bus is not blocked. 1 = off Pin PC7 input to PLD Input Bus is blocked, saving power. Bit 7 X 0 Not used, and should be set to zero. Bit 0 X 0 Not used, and should be set to zero. Bit 1 FORCE_PD 0 = off APD counter will cause Power-Down Mode if APD is enabled. 1 = on Power-Down mode will be entered immediately regardless of APD activity. Bit 3-7 X 0 Not used, and should be set to zero.189/231 uPSD33xx Automatic Power-Down (APD). The APD unit shown in Figure 63., page 157 puts the PSD Module into power-down mode by monitoring the activity of the 8032 Address Latch Enable (ALE) signal. If the APD unit is enabled by writing a logic ’1’ to Bit 1 of the csiop PMMR0 register, and if ALE signal activity has stopped (8032 in sleep mode), then the four-bit APD counter starts counting up. If the ALE signal remains inactive for 15 clock periods of the CLKIN signal (pin PD1), then the APD counter will reach maximum count and the power down indicator signal (PDN) goes to logic ’1’ forcing the PSD Module into power-down mode. During this time, all buffers on the PSD Module for 8032 address and data signals are disabled in silicon, preventing the PSD Module memories from waking up from stand-by mode, even if noise or other devices are driving the address lines. The PLDs will also stay in standby mode if the PLDs are in non-Turbo mode and if all other PLD inputs (non-address signals) are static. However, if the ALE signal has a transition before the APD counter reaches max count, the APD counter is cleared to zero and the PDN signal will not go active, preventing power-down mode. To prevent unwanted APD time-outs during normal 8032 operation (not sleeping), it is important to choose a clock frequency for CLKIN that will NOT produce 15 or more pulses within the longest period between ALE transitions. A 32768 Hz clock signal is quite often an ideal frequency for CLKIN and APD, and this frequency is often available on external supervisor or real-time clock devices. The “PDN” power-down indicator signal is available to the PLD input bus to use in any PLD equations if desired. The user may want to send this signal as a PLD output to an external device to indicate the PSD Module is in power-down mode. PSDsoft Express automatically includes the “PDN” signal in the DPLD chip select equations for FSx, CSBOOTx, RS0, and CSIOP. The following should be kept in mind when the PSD Module is in power-down mode: – 8032 address and data bus signals are blocked from all memories and both PLDs. – The PSD Module comes out of power-down mode when: ALE starts pulsing again, or the CSI input on pin PD2 transitions from logic ’1’ to logic '0,' or the PSD Module reset signal, RST, transitions from logic ’0’ to logic '1.' – Various signals can be blocked (prior to power-down mode) from entering the PLDs by using “blocking bits” in csiop PMMR registers. – All memories enter standby mode, and the state of the PLDs and I/O Ports are unchanged (if no PLD inputs change). Table 121., page 194 shows the effects of powerdown mode on I/O pins while in various operating modes. – The 8032 Ports 1,3, and 4 on the MCU Module are not affected at all by power-down mode in the PSD Module. – Power-down standby current given in the AC specifications for PSD Module assume there are no transitions on any unblocked PLD input, and there are no output pins driving any loads. The APD counter will count whenever Bit 1 of csiop PMMR0 register is set to logic '1,' and when the ALE signal is steady at either logic ’1’ or logic ’0’ (not transitioning). Figure 79., page 191 shows the flow leading up to power-down mode. The only action required in PSDsoft Express to enable APD mode is to select the pin function “Common Clock Input, CLKIN” before programming with JTAG.uPSD33xx 190/231 Forced Power Down (FDP). An alternative to APD is FPD. The resulting power-savings is the same, but the PDN signal in Figure 78., page 191 is set and Power-Down mode is entered immediately when firmware sets the FORCE_PD Bit to logic '1' in the csiop Register PMMR3 (Bit 1). FPD will override APD counter activity when FORCE_PD is set. No external clock source for the APD counter is needed. The FORCE_PD Bit is cleared only by a reset condition. Caution must be used when implementing FPD because code memory goes off-line as soon as PSD Module Power-Down mode is entered, leaving the MCU with no instruction stream to execute. The MCU Module must put itself into Power-Down mode after it puts the PSD Module into PowerDown Mode. How can it do this if code memory goes off-line? The answer is the Pre-Fetch Queue (PFQ) in the MCU Module. By using the instruction scheme shown in the 8051 assembly code example in Table 120, the PFQ will be loaded with the final instructions to command the MCU Module to Power Down mode after the PDS Module goes to Power-Down mode. In this case, even though the code memory goes off-line in the PSD Module, the last few MCU instruction are sourced from the PFQ. Table 120. Forced Power-Down Example PDOWN: ANL A8h, #7Fh ; disable all interrupts ORL 9Dh, #C0h ; ensure PFQ and BC are enabled MOV DPTR, #xxC7 ; load XDATA pointer to select PMMR3 register (xx = base ; address of csiop registers) CLR A ; clear A JMP LOOP ; first loop - fill PFQ/BQ with Power Down instructions NOP ; second loop - fetch code from PFQ/BC and set Power- ; Down bits for PSD Module and then MCU Module LOOP: MOVX @DPTR, A ; set FORCE_PD Bit in PMMR3 in PSD Module in second ; loop MOV 87h, A ; set PD Bit in PCON Register in MCU Module in second ; loop MOV A, #02h ; set power-down bit in the A Register, but not in PMMR3 or ; PCON yet in first loop JMP LOOP ; uPSD enters into Power-Down mode in second loop191/231 uPSD33xx Figure 78. Automatic Power Down (APD) Unit Figure 79. Power-Down Mode Flow Chart Chip Select Input (CSI). Pin PD2 of Port D can optionally be configured in PSDsoft Express as the PSD Module Chip Select Input, CSI, which is an active-low logic input. By default, pin PD2 does not have the CSI function. When the CSI function is specified in PSDsoft Express, the CSI signal is automatically included in DPLD chip select equations for FSx, CSBOOTx, RS0, and CSIOP. When the CSI pin is driven to logic ’0’ from an external device, all of these memories will be available for READ and WRITE operations. When CSI is driven to logic '1,' none of these memories are available for selection, regardless of the address activity from the 8032, reducing power consumption. The state of the PLD and port I/O pins are not changed when CSI goes to logic ’1’ (disabled). PMMR0, BIT 1 (APD EN) 8032 ALE PSD MODULE RST_ CSI (pin PD2) CLKIN (pin PD1) PDN OMC OUTPUTS FSx CSBOOTx RS0 CSIOP 8032 DATA FROM MCU MODULE 8032 ADDR FROM MCU MODULE PDN PDN CSI PMMR3, BIT 1 (FORCE_PD) ENABLE 1 = FOUND TRANSITION 1 = FOUND EDGE CLEAR FULL COUNT DPLD CHIP SELECT EQUATIONS GPLD TRANSITION DETECTION EDGE DETECTION 4-BIT APD UP-COUNTER ENABLE CLK 1 = POWER DOWN MODE ENABLE PSD MODULE LINE BUFFERS 8032 DATA 8032 ADDR WHEN CSI FUNCTION IS SPECIFIED IN PSDSOFT EXPRESS, CSI IS PART OF EQUATIONS FOR FSx, CSBOOTx, RS0, and CSIOP AI06608B Enable APD. Set PMMR0, Bit 1 = 1 RESET OPTIONAL. Disable desired inputs to PLDs by setting PMMR0 bits 4 and 5, and PMMR2 bits 2 through 6 ALE idle for 15 CLKIN clocks? PDN = 1, PSD Module in PowerDown Mode YES NO AI09183uPSD33xx 192/231 PLD Non-Turbo Mode. The power consumption and speed of the PLDs are controlled by the Turbo Bit (Bit 3) in the csiop PMMR0 register. By setting this bit to logic '1,' the Turbo mode is turned off and both PLDs consume only stand-by current when ALL PLD inputs have no transitions for an extended time (65ns for 5V devices, 100ns for 3.3 V devices), significantly reducing current consumption. The PLDs will latch their outputs and go to standby, drawing very little current. When Turbo mode is off, PLD propagation delay time is increased as shown in the AC specifications for the PSD Module. Since this additional propagation delay also effects the DPLD, the response time of the memories on the PSD Module is also lengthened by that same amount of time. If Turbo mode is off, the user should add an additional wait state to the 8032 BUSCON SFR register if the 8032 clock frequency is higher that a particular value. Please refer to Table 36., page 64 in the MCU Module section. The default state of the Turbo Bit is logic '0,' meaning Turbo mode is on by default (after power-up and reset conditions) until it is turned off by the 8032 writing to PMMR0. PLD Current Consumption. Figure 85., page 202 and Figure 86., page 202 (5V and 3.3V devices respectively) show the relationship between PLD current consumption and the composite frequency of all the transitions on PLD inputs, indicating that a higher input frequency results in higher current consumption. Current consumption of the PLDs have a DC component and an AC component. Both need to be considered when calculating current consumption for a specific PLD design. When Turbo mode is on, there is a linear relationship between current and frequency, and there is a substantial DC current component consumed by the PSD Module when there are no transitions on PLD inputs (composite frequency is zero). The magnitude of this DC current component is directly proportional to how many product terms are used in the equations of both PLDs. PSDsoft Express generates a “fitter” report that specifies how many product terms were used in a design out of a total of 186 available product terms. Figure 85., page 202 and Figure 86., page 202 both give two examples, one with 100% of the 186 product terms used, and another with 25% of the 186 product terms used. Turbo Mode Current Consumption. To determine the AC current component of the specific PLD design with Turbo mode on, the user will have to interpolate from the graph, given the number of product terms specified in the fitter report, and the estimated composite frequency of PLD input signal transitions. For the DC component (y-axis crossing), the user can calculate the number by multiplying the number of product terms used (from fitter report) times the DC current per product term specified in the DC specifications for the PSD Module. The total PLD current usage is the sum of its AC and DC components. Non-Turbo Mode Current Consumption. Notice in Figure 85., page 202 and Figure 86., page 202 that when Turbo mode is off, the DC current consumption is “zero” (just standby current) when the composite frequency of PLD input transitions is zero (no input transitions). Now moving up the frequency axis to consider the AC current component, current consumption remains considerably less than Turbo mode until PLD input transitions happen so rapidly that the PLDs do not have time to latch their outputs and go to standby between the transitions anymore. This is where the lines converge on the graphs, and current consumption becomes the same for PLD input transitions at this frequency and higher regardless if Turbo mode is on or off. To determine the current consumption of the PLDs with Turbo mode off, extrapolate the AC component from the graph based on number of product terms and input frequency. The only DC component in non-Turbo mode is the PSD Module standby current. The key to reducing PLD current consumption is to reduce the composite frequency of transitions on the PLD input bus, moving down the frequency scale on the graphs. One way to do this is to carefully select which signals are entering PLD inputs, not selecting high frequency signals if they are not used in PLD equations. Another way is to use PLD “Blocking Bits” to block certain signals from entering the PLD input bus.193/231 uPSD33xx PLD Blocking Bits. Blocking specific signals from entering the PLDs using bits of the csiop PMMR registers can further reduce PLD AC current consumption by lowering the effective composite frequency of inputs to the PLDs. Blocking 8032 Bus Control Signals. When the 8032 is active on the MCU Module, four bus control signals (RD, WR, PSEN, and ALE) are constantly transitioning to manage 8032 bus traffic. Each time one of these signals has a transition from logic ’1’ to '0,' or 0 to '1,' it will wake up the PLDs if operating in non-Turbo mode, or when in Turbo mode it will cause the affected PLD gates to draw current. If equations in the DPLD or GPLD do not use the signals RD, WR, PSEN, or ALE then these signals can be blocked which will reduce the AC current component substantially. These bus control signals are rarely used in DPLD equations because they are routed in silicon directly to the memory arrays of the PSD Module, bypassing the PLDs. For example, it is NOT necessary to qualify a memory chip select signal with an MCU write strobe, such as “fs0 = address range & !WR_”. Only “fs0 = address range” is needed. Each of the 8032 bus control signals may be blocked individually by writing to Bits 2, 3, 4, and 5 of the PMMR2 register shown in Table 118., page 188. Blocking any of these four bus control signals only prevents them from reaching the PLDs, but they will always go to the memories directly. However, sometimes it is necessary to use these 8032 bus control signals in the GPLD when creating interface signals to external I/O peripherals. But it is still possible to save power by dynamically unblocking the bus signals before reading/writing the external device, then blocking the signals after the communication is complete. The user can also block an input signal coming from pin PC7 to the PLD input bus if desired by writing to Bit 6 of PMMR2. Blocking Common Clock, CLKIN. The input CLKIN (from pin PD1) can be blocked to reduce current consumption. CLKIN is used as a common clock input to all OMC flip-flips, it is a general input to the PLD input bus, and it is used to clock the APD counter. In PSDsoft Express, the function of pin PD1 must be specified as “Common Clock Input, CLKIN” before programming the device with JTAG to get the CLKIN function. Bit 4 of PMMR0 can be set to logic ’1’ to block CLKIN from reaching the PLD input bus, but CLKIN will still reach the APD counter. Bit 5 of PMMR0 can be set to logic ’1’ to block CLKIN from reaching the OMC flip-flops only, but CLKIN is still available to the PLD input bus and the APD counter. See Table 117., page 188 for details. SRAM Standby Mode (battery backup). The SRAM on the PSD Module may optionally be backed up by an external battery (or other DC source) to make its contents non-volatile. This is achieved by connecting a battery to pin PC2 on Port C and selecting the “SRAM Standby” function for pin PC2 within PSDsoft Express. Automatic voltage supply cross-over circuitry is built into the PSD Module to switch SRAM supply to battery as soon as VDD drops below the voltage level of the battery. SRAM contents are protected while battery voltage is greater than 2.0V. Pin PC4 on Port C can be used as an output to indicate that a battery switch-over has occurred. This is configured in PSDsoft Express by selecting the “Standby On Indicator” option for pin PC4. PSD Module Reset Conditions The PSD Module receives a reset signal from the MCU Module. This reset signal is referred to as the “RST” input in PSD Module documentation, and it is active-low when asserted. The character of the RST signal generated from the MCU Module is described in SUPERVISORY FUNCTIONS, page 65. Upon power-up, and while RST is asserted, the PSD Module immediately loads its configuration from non-volatile bits to configure the PLDs and other items. PLD logic is operational and ready for use well before RST is de-asserted. The state of PLD outputs are determined by equations specified in PSDsoft Express. The Flash memories are reset to Read Array mode after any assertion of RST (even if a program or erase operation is occurring). Flash memory WRITE operations are automatically prevented while VDD is ramping up until it rises above the VLKO voltage threshold at which time Flash memory WRITE operations are allowed. Once the uPSD33xx is up and running, any subsequent reset operation is referred to as a warm reset, until power is turned off again. Some PSD Module functions are reset in different ways depending if the reset condition was caused from a power-up reset or a warm reset. Table 121., page 194 summarizes how PSD Module functions are affected by power-up and warm resets, as well as the affect of PSD Module powerdown mode (from APD). The I/O pins of PSD Module Ports A, B, C, and D do not have weak internal pull-ups.uPSD33xx 194/231 In MCU I/O mode, Latched Address Out mode, and Peripheral I/O mode, the pins of Ports A, B, C, and D become standard CMOS inputs during a reset condition. If no external devices are driving these pins during reset, then these inputs may float and draw excessive current. If low power consumption is critical during reset, then these floating inputs should be pulled up externally to VDD with a weak (100KΩ minimum) resistor. In PLD I/O mode, pins of Ports A, B, C, and D may also float during reset if no external device is driving them, and if there is no equation specified for the DPLD or GPLD to make them an output. In this case, a weak external pull-up resistor (100KΩ minimum) should be used on floating pins to avoid excessive current draw. The pins on Ports 1, 3, and 4 of the 8032 MCU module do have weak internal pull-ups and the inputs will not float, so no external pull-ups are needed. Table 121. Function Status During Power-Up Reset, Warm Reset, Power-down Mode Note: 1. VM register Bit 7 (PIO_EN) and Bit 0 (SRAM in 8032 program space) are cleared to zero at power-up and warm reset conditions. Port Configuration Power-Up Reset Warm Reset APD Power-down Mode MCU I/O Pins are in input mode Pins are in input mode Pin logic state is unchanged PLD I/O Pin logic is valid after internal PSD Module configuration bits are loaded. Happens long before RST is de-asserted Pin logic is valid and is determined by PLD logic equations Pin logic depends on inputs to PLD (8032 addresses are blocked from reaching PLD inputs during powerdown mode) Latched Address Out Mode Pins are High Impedance Pins are High Impedance Pins logic state not defined since 8032 address signals are blocked Peripheral I/O Mode Pins are High Impedance Pins are High Impedance Pins are High Impedance JTAG ISP and Debug JTAG channel is active and available JTAG channel is active and available JTAG channel is active and available Register Power-Up Reset Warm Reset APD Power-down Mode PMMR0 and PMMR2 Cleared to 00h Unchanged Unchanged Output of OMC Flip-flops Cleared to ’0’ Depends on .re and .pr equations Depends on .re and .pr equations VM Register(1) Initialized with value that was specified in PSDsoft Initialized with value that was specified in PSDsoft Unchanged All other csiop registers Cleared to 00h Cleared to 00h Unchanged195/231 uPSD33xx JTAG ISP and JTAG Debug. An IEEE 1149.1 serial JTAG interface is used on uPSD33xx devices for ISP (In-System Programming) of the PSD module, and also for debugging firmware on the MCU Module. IEEE 1149.1 Boundary Scan operations are not supported in the uPSD33xx. The main advantage of JTAG ISP is that a blank uPSD33xx device may be soldered to a circuit board and programmed with no involvement of the 8032, meaning that no 8032 firmware needs to be present for ISP. This is good for manufacturing, for field updates, and for easy code development in the lab. JTAG-based programmers and debuggers for uPSD33xx are available from STMicroelectronics and 3rd party vendors. ISP is different than IAP (In-Application Programming). IAP involves the 8032 to program Flash memory over any interface supported by the 8032 (e.g., UART, SPI, I2C), which is good for remote updates over a communication channel. uPSD33xx devices support both ISP and IAP. The entire PSD Module (Flash memory and PLD) may be programmed with JTAG ISP, but only the Flash memories may be programmed using IAP. JTAG Chaining Inside the Package. JTAG protocol allows serial “chaining” of more than one device in a JTAG chain. The uPSD33xx is assembled with a stacked die process combining the PSD Module (one die) and the MCU Module (the other die). These two die are chained together within the uPSD33xx package. The standard JTAG interface has four basic signals: ■ TDI - Serial data into device ■ TDO - Serial data out of device ■ TCK - Common clock ■ TMS - Mode Selection Every device that supports IEEE 1149.1 JTAG communication contains a Test Access Port (TAP) controller, which is a small state machine to manage JTAG protocol and serial streams of commands and data. Both the PSD Module and the MCU Module each contain a TAP controller. Figure 80 illustrates how these die are chained within a package. JTAG programming/test equipment will connect externally to the four IEEE 1149.1 JTAG pins on Port C. The TDI pin on the uPSD33xx package goes directly to the PSD Module first, then exits the PSD Module through TDO. TDO of the PSD Module is connected to TDI of the MCU Module. The serial path is completed when TDO of the MCU Module exits the uPSD33xx package through the TDO pin on Port C. The JTAG signals TCK and TMS are common to both modules as specified in IEEE 1149.1. When JTAG devices are chained, typically one devices is in BYPASS mode while another device is executing a JTAG operation. For the uPSD33xx, the PSD Module is in BYPASS mode while debugging the MCU Module, and the MCU Module is in BYPASS mode while performing ISP on the PSD Module. The RESET_IN input pin on the uPSD33xx package goes to the MCU Module, and this module will generate the RST reset signal for the PSD Module. These reset signals are totally independent of the JTAG TAP controllers, meaning that the JTAG channel is operational when the modules are held in reset. It is required to assert RESET_IN during ISP. STMicroelectronics and 3rd party JTAG ISP tools will automatically assert a reset signal during ISP. However, this reset signal must be connected to RESET_IN as shown in examples in Figure Figure 81., page 196 and Figure 82., page 198. Figure 80. JTAG Chain in uPSD33xx Package JTAG TDI JTAG TMS JTAG TCK JTAG TDO TDI TMS TCK TDO TDO TMS TCK TDI PC3 / TSTAT PC4 / TERR TSTAT TERR OPTIONAL JTAG TAP CONTROLLER JTAG TAP CONTROLLER RESET_IN OPTIONAL DEBUG RESET RST 8032 MCU MCU MODULE PSD MODULE MAIN FLASH MEMORY 2ND FLASH MEMORY PLD uPSD33XX IEEE 1149.1 AI09184uPSD33xx 196/231 In-System Programming. The ISP function can use two different configurations of the JTAG interface: ■ 4-pin JTAG: TDI, TDO, TCK, TMS ■ 6-pin JTAG: Signals above plus TSTAT, TERR At power-up, the four basic JTAG signals are all inputs, waiting for a command to appear on the JTAG bus from programming or test equipment. When the enabling command is received, TDO becomes an output and the JTAG channel is fully functional. The same command that enables the JTAG channel may optionally enable the two additional signals, TSTAT and TERR. 4-pin JTAG ISP (default). The four basic JTAG pins on Port C are enabled for JTAG operation at all times. These pins may not be used for other I/ O functions. There is no action needed in PSDsoft Express to configure a device to use 4-pin JTAG, as this is the default condition. No 8032 firmware is needed to use 4-pin ISP because all ISP functions are controlled from the external JTAG program/test equipment. Figure 81 shows recommended connections on a circuit board to a JTAG program/test tool using 4-pin JTAG. It is required to connect the RST output signal from the JTAG program/test equipment to the RESET_IN input on the uPSD33xx. The RST signal is driven by the equipment with an Open Drain driver, allowing other sources (like a push button) to drive RESET_IN without conflict. Note: The recommended pull-up resistors and decoupling capacitor are illustrated in Figure 81. Figure 81. Recommended 4-pin JTAG Connections Note: 1. For 5V uPSD33xx devices, pull-up resistors and VCC pin on the JTAG connector should be connected to 5V system VDD. 2. For 3.3V uPSD33xx devices, pull-up resistors and VCC pin on the JTAG connector should be connected to 3.3V system VCC. 3. This signal is driven by an Open-Drain output in the JTAG equipment, allowing more than one source to activate RESETIN. TMS - PC0 TCK - PC1 SRAM STBY or I/O - PC2 GENERAL I/O - PC3 GENERAL I/O - PC4 TDI - PC5 TDO - PC6 GENERAL I/O - PC7 JTAG CONN. 100k typical TMS TCK TDI TDO GENERAL I/O SIGNALS GND VCC (1,2) RST(3) uPSD33XX 0.01 µF CIRCUIT BOARD JTAG Programming or Test Equipment Connects Here 10k PUSH BUTTON or ANY OTHER RESET SOURCE DEBUG OPTIONAL TEST POINT 100k RESETIN AI09185197/231 uPSD33xx 6-pin JTAG ISP (optional). The optional signals TSTAT and TERR are programming status flags that can reduce programming time by as much as 30% compared to 4-pin JTAG because this status information does not have to be scanned out of the device serially. TSTAT and TERR must be used as a pair for 6-pin JTAG operation. – TSTAT (pin PC3) indicates when programming of a single Flash location is complete. Logic 1 = Ready, Logic 0 = busy. – TERR (pin PC4) indicates if there was a Flash programming error. Logic 1 = no error, Logic 0 = error. The pin functions for PC3 and PC4 must be selected as “Dedicated JTAG - TSTAT” and “Dedicated JTAG - TERR” in PSDsoft Express to enable 6-pin JTAG ISP. No 8032 firmware is needed to use 6-pin ISP because all ISP functions are controlled from the external JTAG program/test equipment. TSTAT and TERR are functional only when JTAG ISP operations are occurring, which means they are non-functional during JTAG debugging of the 8032 on the MCU Module. Programming times vary depending on the number of locations to be programmed and the JTAG programming equipment, but typical JTAG ISP programming times are 10 to 25 seconds using 6- pin JTAG. The signals TSTAT and TERR are not included in the IEEE 1149.1 specification. Figure 82., page 198 shows recommended connections on a circuit board to a JTAG program/test tool using 6-pin JTAG. It is required to connect the RST output signal from the JTAG program/test equipment to the RESET_IN input on the uPSD33xx. The RST signal is driven by the equipment with an Open Drain driver, allowing other sources (like a push button) to drive RESET_IN without conflict. Note: The recommended pull-up resistors and decoupling capacitor are illustrated in Figure 82.uPSD33xx 198/231 Figure 82. Recommended 6-pin JTAG Connections Note: 1. For 5V uPSD33xx devices, pull-up resistors and VCC pin on the JTAG connector should be connected to 5V system VDD. 2. For 3.3V uPSD33xx devices, pull-up resistors and VCC pin on the JTAG connector should be connected to 3.3V system VCC. 3. This signal is driven by an Open-Drain output in the JTAG equipment, allowing more than one source to activate RESET_IN. TMS - PC0 TCK - PC1 SRAM STBY or I/O - PC2 TSTAT - PC3 TERR - PC4 TDI - PC5 TDO - PC6 GENERAL I/O - PC7 JTAG CONN. 100k typical TMS TCK TDI TERR TSTAT TDO GENERAL I/O SIGNALS GND VCC (1,2) RST(3) uPSD33XX 0.01 µF CIRCUIT BOARD JTAG Programming or Test Equipment Connects Here 10k PUSH BUTTON or ANY OTHER RESET SOURCE DEBUG OPTIONAL TEST POINT 100k RESETIN AI09186199/231 uPSD33xx Recommended JTAG Connector. There is no industry standard JTAG connector. STMicroelectronics recommends a specific JTAG connector and pinout for uPSD3xxx so programming and debug equipment will easily connect to the circuit board. The user does not have to use this connector if there is a different connection scheme. The recommended connector scheme can accept a standard 14-pin ribbon cable connector (2 rows of 7 pins on 0.1” centers, 0.025” square posts, standard keying) as shown in Figure 83. See the STMicroelectronics “FlashLINK, FL-101 User Manual” for more information. Figure 83. Recommended JTAG Connector Chaining uPSD33xx Devices. It is possible to chain a uPSD33xx device with other uPSD33xx devices on a circuit board, and also chain with IEEE 1149.1 compliant devices from other manufacturers. Figure 84., page 200 shows a chaining example. The TDO of one device connects to the TDI of the next device, and so on. Only one device is performing JTAG operations at any given time while the other two devices are in BYPASS mode. Configuration for JTAG chaining can be made in PSDsoft Express by choosing “More than one device” when prompted about chaining devices. Notice in Figure 84., page 200 that the uPSD33xx devices are chained externally, but also be aware that the two die within each uPSD33xx device are chained internally. This internal chaining of die is transparent to the user and is taken care of by PSDsoft Express and 3rd party JTAG tool software. The example in Figure 84., page 200 also shows how to use 6-pin JTAG when chaining devices. The signals TSTAT and TERR are configured as open-drain type signals from PSDsoft Express. This facilitates a wired-OR connection of TSTAT signals from multiple uPSD33xx devices and also a wired-OR connection of TERR signals from those same multiple devices. PSDsoft Express puts TSTAT and TERR signals into open-drain mode by default, requiring external pull-up resistors. Click on 'Properties' in the JTAG-ISP window of PSDsoft Express to change to standard CMOS push-pull outputs if desired, but wired-OR logic is not possible in CMOS output mode. TDO TCK TMS VCC TDI GND JEN TERR GND GND RST TSTAT CNTL TRST 14 12 10 13 11 9 8 7 6 5 4 3 2 1 KEY WAY VIEW: Looking into face of shrouded male connector, with 0.025" posts on 0.1" centers. Connector reference: Molex 70247-1401 This connector accepts a 14-pin ribbon cable such as: • Samtec: HCSD-07-D-06.00-01-S-N • Digikey: M3CCK-14065-ND AI09187uPSD33xx 200/231 Figure 84. Example of Chaining uPSD33xx Devices Device 1 µPSD33XX uPSD33XX TMS TCK TDI TDO IEEE 1149.1 Compliant Device Device 2 Device N System Reset Circuitry TMS TCK TDI TDO TSTAT TERR CIRCUIT BOARD JTAG CONN. VCC TMS TCK TDI TSTAT TERR TDO RST GND 100K 100K 100K 100K 100K 10K 100K JTAG Programming or Test Equipment Connects Here Optional Optional TMS TCK TDI TDO TSTAT TERR AI09188201/231 uPSD33xx Debugging the 8032 MCU Module. The 8032 on the MCU module may be debugged in-circuit using the same four basic JTAG signals as used for JTAG ISP (TDI, TDO, TCK, TMS). The signals TSTAT and TERR are not needed for debugging, and they will not create a problem if they exist on the circuit board while debugging. The same connector specified in Figure 83., page 199 can be used for ISP or for 8032 debugging. There are 3rd party suppliers of uPSD33xx JTAG debugging equipment (check www.st.com/psm). These are small pods which connect to a PC (or notebook computer) using a USB interface, and they are driven by an 8032 Integrated Development Environment (IDE) running on the PC. Standard debugging features are provided through this JTAG interface such as single-step, breakpoints, trace, memory dump and fill, and others. There is also a dedicated Debug pin (shown in Figure 80., page 195) which can be configured as an output to trigger external devices upon a programmable internal event (e.g., breakpoint match), or the pin can be configured as an input so an external device can initiate an internal debug event (e.g., break execution). The Debug pin function is configured by the 8032 IDE debug software tool. See DEBUG UNIT, page 39 for more details. The Debug signal should always be pulled up externally with a weak pull-up (100K minimum) to VCC even if nothing is connected to it, as shown in Figure 81., page 196 and Figure 82., page 198. JTAG Security Setting. A programmable security bit in the PSD Module protects its contents from unauthorized viewing and copying. The security bit is set by clicking on the “Additional PSD Settings” box in the main flow diagram of PSDsoft Express, then choosing to set the security bit. Once a file with this setting is programmed into a uPSD33xx using JTAG ISP, any further attempts to communicate with the uPSD33xx using JTAG will be limited. Once secured, the only JTAG operation allowed is a full-chip erase. No reading or modifying Flash memory or PLD logic is allowed. Debugging operations to the MCU Module are also not allowed. The only way to defeat the security bit is to perform a JTAG ISP full-chip erase operation, after which the device is blank and may be used again. The 8032 on the MCU Module will always have access to PSM Module memory contents through the 8-bit 8032 data bus connecting the two die, even while the security bit is set. Initial Delivery State. When delivered from STMicroelectronics, uPSD33xx devices are erased, meaning all Flash memory and PLD configuration bits are logic '1.' Firmware and PLD logic configuration must be programmed at least the first time using JTAG ISP. Subsequent programming of Flash memory may be performed using JTAG ISP, JTAG debugging, or the 8032 may run firmware to program Flash memory (IAP).uPSD33xx 202/231 AC/DC PARAMETERS These tables describe the AD and DC parameters of the uPSD33xx Devices: ■ DC Electrical Specification ■ AC Timing Specification ■ PLD Timing – Combinatorial Timing – Synchronous Clock Mode – Asynchronous Clock Mode – Input Macrocell Timing ■ MCU Module Timing – READ Timing – WRITE Timing – Power-down and RESET Timing The following are issues concerning the parameters presented: – In the DC specification the supply current is given for different modes of operation. – The AC power component gives the PLD, Flash memory, and SRAM mA/MHz specification. Figure 85 and Figure 86 show the PLD mA/MHz as a function of the number of Product Terms (PT) used. – In the PLD timing parameters, add the required delay when Turbo Bit is '0.' Figure 85. PLD ICC /Frequency Consumption (5V range) Figure 86. PLD ICC /Frequency Consumption (3V range) 0 10 20 30 40 60 70 80 90 100 110 VCC = 5V 50 0 10 15 5 20 25 HIGHEST COMPOSITE FREQUENCY AT PLD INPUTS (MHz) ICC – (mA) TURBO ON (100%) TURBO ON (25%) TURBO OFF TURBO OFF PT 100% PT 25% AI02894 0 10 20 30 40 50 60 VCC = 3V 0 10 15 5 20 25 ICC – (mA) TURBO ON (100%) TURBO ON (25%) TURBO OFF TURBO OFF HIGHEST COMPOSITE FREQUENCY AT PLD INPUTS (MHz) PT 100% PT 25% AI03100203/231 uPSD33xx Table 122. PSD Module Example, Typ. Power Calculation at VCC = 5.0V (Turbo Mode Off) Conditions MCU Clock Frequency = 12MHz Highest Composite PLD input frequency (Freq PLD) = 8MHz MCU ALE frequency (Freq ALE) = 2MHz % Flash memory Access = 80% % SRAM access = 15% % I/O access = 5% (no additional power above base) Operational Modes % Normal = 40% % Power-down Mode = 60% Number of product terms used (from fitter report) = 45 PT % of total product terms = 45/182 = 24.7% Turbo Mode = Off Calculation (using typical values) ICC total = ICC(MCUactive) x %MCUactive + ICC(PSDactive) x %PSDactive + IPD(pwrdown) x %pwrdown ICC(MCUactive) = 20mA IPD(pwrdown) = 250uA ICC(PSDactive) = ICC(ac) + ICC(dc) = %flash x 2.5mA/MHz x Freq ALE + %SRAM x 1.5mA/MHz x Freq ALE + % PLD x (from graph using Freq PLD) = 0.8 x 2.5mA/MHz x 2MHz + 0.15 x 1.5mA/MHz x 2MHz + 24mA = (4 + 0.45 + 24) mA = 28.45mA ICC total = 20mA x 40% + 28.45mA x 40% + 250uA x 60% = 8mA + 11.38mA + 150uA = 19.53mA This is the operating power with no Flash memory Erase or Program cycles in progress. Calculation is based on all I/O pins being disconnected and IOUT = 0mA.uPSD33xx 204/231 MAXIMUM RATING Stressing the device above the rating listed in the Absolute Maximum Ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 123. Absolute Maximum Ratings Note: 1. IPC/JEDEC J-STD-020A 2. JEDEC Std JESD22-A114A (C1=100pF, R1=1500 Ω, R2=500 Ω) DC AND AC PARAMETERS This section summarizes the operating and measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC Characteristic tables that follow are derived from tests performed under the Measurement Conditions summarized in the relevant tables. Designers should check that the operating conditions in their circuit match the measurement conditions when relying on the quoted parameters. Table 124. Operating Conditions (5V Devices) Table 125. Operating Conditions (3.3V Devices) Symbol Parameter Min. Max. Unit TSTG Storage Temperature –65 125 °C TLEAD Lead Temperature during Soldering (20 seconds max.)(1) 235 °C VIO Input and Output Voltage (Q = VOH or Hi-Z) –0.5 6.5 V VCC Supply Voltage –0.5 6.5 V VPP Device Programmer Supply Voltage –0.5 14.0 V VESD Electrostatic Discharge Voltage (Human Body Model)(2) –2000 2000 V Symbol Parameter Min. Max. Unit VCC Supply Voltage 4.5 5.5 V TA Ambient Operating Temperature (industrial) –40 85 °C Ambient Operating Temperature (commercial) 0 70 °C Symbol Parameter Min. Max. Unit VCC Supply Voltage 3.0 3.6 V TA Ambient Operating Temperature (industrial) –40 85 °C Ambient Operating Temperature (commercial) 0 70 °C205/231 uPSD33xx Table 126. AC Signal Letters for Timing Note: Example: tAVLX = Time from Address Valid to ALE Invalid. Table 127. AC Signal Behavior Symbols for Timing Note: Example: tAVLX = Time from Address Valid to ALE Invalid. Figure 87. Switching Waveforms – Key A Address C Clock D Input Data I Instruction L ALE N RESET Input or Output P PSEN signal Q Output Data R RD signal W WR signal B VSTBY Output M Output Macrocell t Time L Logic Level Low or ALE H Logic Level High V Valid X No Longer a Valid Logic Level Z Float PW Pulse Width WAVEFORMS INPUTS OUTPUTS STEADY INPUT MAY CHANGE FROM HI TO LO MAY CHANGE FROM LO TO HI DON'T CARE OUTPUTS ONLY STEADY OUTPUT WILL BE CHANGING FROM HI TO LO WILL BE CHANGING LO TO HI CHANGING, STATE UNKNOWN CENTER LINE IS TRI-STATE AI03102uPSD33xx 206/231 Table 128. Major Parameters Parameter Test Conditions/Comments 5.0V Value 3.3V Value Unit Operating Voltage – 4.5 to 5.5 (PSD); 3.0 to 3.6 (MCU) 3.0 to 3.6 (PSD and MCU) V Operating Temperature – –40 to 85 –40 to 85 °C MCU Frequency 8MHz (min) for I2C 1 Min, 40 Max 1 Min, 40 Max MHz Active Current, Typical (20% of PLD used; 25°C operation) 40MHz Crystal, Turbo 50 40 mA 40MHz Crystal, Non-Turbo 48 38 mA 8MHz Crystal, Turbo 21 18 mA 8MHz Crystal, Non-Turbo 10 8 mA Idle Current, Typical (20% of PLD used; 25°C operation) 40MHz Crystal divided by 2048 internally. All interfaces are disabled. 16 11 mA Standby Current, Typical Power-down Mode needs reset to exit. 140 120 µA SRAM Backup Current, Typical If external battery is attached. 0.5 0.5 µA I/O Sink/Source Current, Ports A, B, C, and D VOL = 0.45V (max); VOH = 2.4V (min) IOL = 8 (max); IOH = –2 (min) IOL = 4 (max); IOH = –1 (min) mA I/O Sink/Source Current, Port 4 VOL = 0.6V (max); VOH = 2.4V (min) IOL = 10 (max); IOH = –10 (min) IOL = 10 (max); IOH = –10 (min) mA PLD Macrocells For registered or combinatorial logic 16 16 – PLD Inputs Inputs from pins, feedback, or MCU addresses 69 69 – PLD Outputs Output to pins or internal feedback 18 18 – PLD Propagation Delay, Typical, Turbo Mode PLD input to output 15 22 ns207/231 uPSD33xx Table 129. Preliminary MCU Module DC Characteristics Note: 1. Power supply (VCC) is always 3.0 to 3.6V for the MCU Module. VDD for the PSD Module may be 3V or 5V. 2. IPD (Power-down Mode) is measured with: XTAL1 = VSS; XTAL2 = NC; RESET = VCC; Port 0 = VCC; all other pins are disconnected. 3. ICC-CPU (Active Mode) is measured with: XTAL1 driven with tCLCH, tCHCL = 5ns, VIL = VSS + 0.5V, VIH = VCC – 0.5V, XTAL2 = NC; RESET = VSS; Port 0 = VCC; all other pins are disconnected. ICC would be slightly higher if a crystal oscillator is used (approximately 1mA). 4. ICC-CPU (Idle Mode) is measured with: XTAL1 driven with tCLCH, tCHCL = 5ns, VIL = VSS + 0.5V, VIH = VCC – 0.5V, XTAL2 = NC; RESET = VCC; Port 0 = VCC; all other pins are disconnected. ICC would be slightly higher if a crystal oscillator is used (approximately 1mA). All IP clocks are disabled. 5. I/O current = 0mA, all I/O pins are disconnected. Symbol Parameter Test Conditions Min. Typ. Max. Unit VCC Supply Voltage(1) 3.0 3.6 V VIH High Level Input Voltage (Ports 0, 1, 2, 3, 4, XTAL1, RESET) 5V Tolerant - max voltage 5.5V 3.0V < VCC < 3.6V 0.7VCC 5.5 V VIL Low Level Input Voltage (Ports 0, 1, 2, 3, 4, XTAL1, RESET) 3.0V < VCC < 3.6V VSS – 0.5 0.3VCC V VOL1 Output Low Voltage (Port 4) IOL = 10mA 0.6 V V VOL2 Output Low Voltage (Other Ports) IOL =5mA 0.6 V V VOH1 Output High Voltage (Ports 4 push-pull) IOH = –10mA 2.4 V V VOH2 Output High Voltage (Port 0 push-pull) IOH = –5mA 2.4 V V VOH3 Output High Voltage (Other Ports Bi-directional mode) IOH = –20µA 2.4 V V VOP XTAL Open Bias Voltage (XTAL1, XTAL2) IOL = 3.2mA 1.0 2.0 V IRST RESET Pin Pull-up Current (RESET) VIN = VSS –10 –55 uA IFR XTAL Feedback Resistor Current (XTAL1) XTAL1 = VCC; XTAL2 = VSS –20 50 uA IIHL1 Input High Leakage Current (Port 0) VSS < VIN < 5.5V –10 10 uA IIHL2 Input High Leakage Current (Port 1, 2, 3, 4) VIH = 2.3V –10 10 uA IILL Input Low Leakage Current (Port 1, 2, 3, 4) VIL < 0.5V –10 10 uA IPD (Note 2) Power-down Mode VCC = 3.6V 65 95 uA ICC-CPU (Note 3,4,5) Active - 12MHz VCC = 3.6V 14 20 mA Idle - 12MHz 10 12 mA Active - 24MHz VCC = 3.6V 19 30 mA Idle - 24MHz 13 17 mA Active - 40MHz VCC = 3.6V 26 40 mA Idle - 40MHz 17 22 mAuPSD33xx 208/231 Table 130. PSD Module DC Characteristics (with 5V VDD) Note: 1. Internal Power-down mode is active. 2. PLD is in non-Turbo mode, and none of the inputs are switching. 3. Please see Figure 85., page 202 for the PLD current calculation. 4. IOUT = 0mA Symbol Parameter Test Condition (in addition to those in Table 129., page 207) Min. Typ. Max. Unit VIH Input High Voltage 4.5V < VDD < 5.5V 2 VDD +0.5 V VIL Input Low Voltage 4.5V < VDD < 5.5V –0.5 0.8 V VLKO VDD (min) for Flash Erase and Program 2.5 4.2 V VOL Output Low Voltage IOL = 20uA, VDD = 4.5V 0.01 0.1 V IOL = 8mA, VDD = 4.5V 0.25 0.45 V VOH Output High Voltage Except VSTBY On IOH = –20uA, VDD = 4.5V 4.4 4.49 V IOH = –2mA, VDD = 4.5V 2.4 3.9 V VOH1 Output High Voltage VSTBY On IOH1 = 1uA VSTBY – 0.8 V VSTBY SRAM Stand-by Voltage 2.0 VDD V ISTBY SRAM Stand-by Current VDD = 0V 0.5 1 uA IIDLE Idle Current (VSTBY input) VDD > VSTBY –0.1 0.1 uA VDF SRAM Data Retention Voltage Only on VSTBY 2 VDD – 0.2 V ISB Stand-by Supply Current for Power-down Mode CSI > VDD – 0.3V (Notes 1,2) 120 250 uA ILI Input Leakage Current VSS < VIN < VDD –1 ±0.1 1 uA ILO Output Leakage Current 0.45 < VOUT < VDD –10 ±5 10 uA ICC (DC) (Note 4) Operating Supply Current PLD Only PLD_TURBO = Off, f = 0MHz (Note 4) 0 uA/PT PLD_TURBO = On, f = 0MHz 400 700 uA/PT Flash memory During Flash memory WRITE/Erase Only 15 30 mA Read only, f = 0MHz 0 0 mA SRAM f = 0MHz 0 0 mA ICC (AC) (Note 4) PLD AC Adder Note 3 Flash memory AC Adder 1.5 2.5 mA/ MHz SRAM AC Adder 1.5 3.0 mA/ MHz209/231 uPSD33xx Table 131. PSD Module DC Characteristics (with 3.3V VDD) Note: 1. Internal PD is active. 2. PLD is in non-Turbo mode, and none of the inputs are switching. 3. Please see Figure 86., page 202 for the PLD current calculation. 4. IOUT = 0mA Symbol Parameter Test Condition (in addition to those in Table 129., page 207) Min. Typ. Max. Unit VIH High Level Input Voltage 3.0V < VDD < 3.6V 0.7VDD VDD +0.5 V VIL Low Level Input Voltage 3.0V < VDD < 3.6V –0.5 0.8 V VLKO VDD (min) for Flash Erase and Program 1.5 2.2 V VOL Output Low Voltage IOL = 20uA, VDD = 3.0V 0.01 0.1 V IOL = 4mA, VDD = 3.0V 0.15 0.45 V VOH Output High Voltage Except VSTBY On IOH = –20uA, VDD = 3.0V 2.9 2.99 V IOH = –1mA, VDD = 3.0V 2.7 2.8 V VOH1 Output High Voltage VSTBY On IOH1 = 1uA VSTBY – 0.8 V VSTBY SRAM Stand-by Voltage 2.0 VDD V ISTBY SRAM Stand-by Current VDD = 0V 0.5 1 uA IIDLE Idle Current (VSTBY input) VDD > VSTBY –0.1 0.1 uA VDF SRAM Data Retention Voltage Only on VSTBY 2 VDD – 0.2 V ISB Stand-by Supply Current for Power-down Mode CSI > VDD – 0.3V (Notes 1,2) 50 100 uA ILI Input Leakage Current VSS < VIN < VDD –1 ±0.1 1 uA ILO Output Leakage Current 0.45 < VIN < VDD –10 ±5 10 uA ICC (DC) (Note 4) Operating Supply Current PLD Only PLD_TURBO = Off, f = 0MHz (Note 2) 0 uA/PT PLD_TURBO = On, f = 0MHz 200 400 uA/PT Flash memory During Flash memory WRITE/Erase Only 10 25 mA Read only, f = 0MHz 0 0 mA SRAM f = 0MHz 0 0 mA ICC (AC) (Note 4) PLD AC Adder Note 3 Flash memory AC Adder 1.0 1.5 mA/ MHz SRAM AC Adder 0.8 1.5 mA/ MHzuPSD33xx 210/231 Figure 88. External PSEN/READ Cycle (80-pin Device Only) Table 132. External PSEN or READ Cycle AC Characteristics (3V or 5V Device) Note: 1. BUSCON Register is configured for 4 PFQCLK. 2. Refer to Table 133 for “n” and “m” values. Table 133. n, m, and x, y Values Symbol Parameter 40MHz Oscillator(1) Variable Oscillator 1/tCLCL = 8 to 40MHz Unit Min Max Min Max tLHLL ALE pulse width 17 tCLCL – 8 ns tAVLL Address setup to ALE 13 tCLCL – 12 ns tLLAX Address hold after ALE 7.5 0.5tCLCL – 5 ns tLLPL ALE to PSEN or RD 7.5 0.5tCLCL – 5 ns tPLPH PSEN or RD pulse width(2) 40 ntCLCL – 10 ns tPXIX Input instruction/data hold after PSEN or RD 2 2 ns tPHIZ Input instruction/data float after PSEN or RD 10.5 0.5tCLCL – 2 ns tPXAV Address hold after PSEN or RD 7.5 0.5tCLCL – 5 ns tAVIV Address to valid instruction/data in(2) 70 mtCLCL – 5 ns tAZPL Address float to PSEN or RD –2 –2 ns # of PFQCLK in BUSCON Reg. PSEN (code) Cycle READ Cycle WRITE Cycle nmnmx y 3 12- - - - 4 232321 5 343432 6 454543 7 - - 5654 tAVLL tPLPH tPXIZ tAVIV211/231 uPSD33xx Figure 89. External WRITE Cycle (80-pin Device Only) Table 134. External WRITE Cycle AC Characteristics (3V or 5V Device) Note: 1. BUSCON Register is configured for 4 PFQCLK. 2. Refer to Table 135, page 151 for “n” and “m” values. Table 135. External Clock Drive Symbol Parameter 40MHz Oscillator(1) Variable Oscillator 1/tCLCL = 8 to 40MHz Unit Min Max Min Max tLHLL ALE pulse width 17 tCLCL – 8 ns tAVLL Address Setup to ALE 13 tCLCL – 12 ns tLLAX Address hold after ALE 7.5 0.5tCLCL – 5 ns tWLWH WR pulse width(2) 40 xtCLCL – 10 ns tLLWL ALE to WR 7.5 0.5tCLCL – 5 ns tAVWL Address valid to WR 27.5 1.5tCLCL – 10 ns tWHLH WR High to ALE High 6.5 14.5 0.5tCLCL – 6 0.5tCLCL + 2 ns tQVWH Data setup before WR(y) 20 ytCLCL – 5 ns tWHQX Data hold after WR 6.5 14.5 0.5tCLCL – 6 0.5tCLCL + 2 ns Symbol Parameter(1) 40MHz Oscillator Variable Oscillator 1/tCLCL = 8 to 40MHz Unit Min Max Min Max tCLCL Oscillator period 25 125 ns tCHCX High time 10 tCLCL – tCLCX ns tCLCX Low time 10 tCLCL – tCLCX ns tCLCH Rise time 10 ns tCHCL Fall time 10 ns MCU A8 - A11 MCU AD0 - AD7 ALE WR PSEN A8-A11 A8-A11 tLLWL tWLWH tAVLL tLHLL tQVWH A0-A7 DATA OUT A0-A7 INSTR IN tLLAX tAVWL tWHQX tWHLH AI07877uPSD33xx 212/231 Table 136. A/D Analog Specification Note: 1. fIN 2kHz, ACLK = 8MHz, AVREF = VCC = 3.3V 2. AVREF = VCC in 52-pin package. Symbol Parameter Test Conditions(1) Min. Typ. Max. Unit IDD Normal Input = AVREF 4.0 mA Power-down 40 uA AVIN Analog Input Voltage GND AVREF V AVREF(2) Analog Reference Voltage 3.6 V Accuracy Resolution 10 bits INL Integral Nonlinearity Input = 0 to AVREF (V) FOSC ≤ 32MHz ±2 LSB DNL Differential Nonlinearity Input = 0 to AVREF (V) FOSC ≤ 32MHz ±2 LSB SNR Signal to Noise Ratio fSAMPLE = 500ksps 50 54 dB SNDR Signal to Noise Distortion Ratio 48 52 dB ACLK ADC Clock 2 8 16 MHz tC Conversion Time 8MHz 1 4 8 µs tCAL Power-up Time Calibration Time 16 ms fIN Analog Input Frequency 60 kHz THD Total Harmonic Distortion 50 54 dB213/231 uPSD33xx Figure 90. Input to Output Disable / Enable Table 137. CPLD Combinatorial Timing (5V PSD Module) Note: 1. Fast Slew Rate output available on PA3-PA0, PB3-PB0, and PD2-PD1. Decrement times by given amount 2. tPD for MCU address and control signals refers to delay from pins on Port 0, Port 2, RD WR, PSEN and ALE to CPLD combinatorial output (80-pin package only) Table 138. CPLD Combinatorial Timing (3V PSD Module) Note: 1. Fast Slew Rate output available on PA3-PA0, PB3-PB0, and PD2-PD1. Decrement times by given amount 2. tPD for MCU address and control signals refers to delay from pins on Port 0, Port 2, RD WR, PSEN and ALE to CPLD combinatorial output (80-pin package only) Symbol Parameter Conditions Min Max PT Aloc Turbo Off Slew rate(1) Unit tPD(2) CPLD Input Pin/Feedback to CPLD Combinatorial Output 20 + 2 + 10 – 2 ns tEA CPLD Input to CPLD Output Enable 21 + 10 – 2 ns tER CPLD Input to CPLD Output Disable 21 + 10 – 2 ns tARP CPLD Register Clear or Preset Delay 21 + 10 – 2 ns tARPW CPLD Register Clear or Preset Pulse Width 10 + 10 ns tARD CPLD Array Delay Any macrocell 11 + 2 ns Symbol Parameter Conditions Min Max PT Aloc Turbo Off Slew rate(1) Unit tPD(2) CPLD Input Pin/Feedback to CPLD Combinatorial Output 35 + 4 + 20 – 6 ns tEA CPLD Input to CPLD Output Enable 38 + 20 – 6 ns tER CPLD Input to CPLD Output Disable 38 + 20 – 6 ns tARP CPLD Register Clear or Preset Delay 35 + 20 – 6 ns tARPW CPLD Register Clear or Preset Pulse Width 18 + 20 ns tARD CPLD Array Delay Any macrocell 20 + 4 ns tER tEA INPUT INPUT TO OUTPUT ENABLE/DISABLE AI02863uPSD33xx 214/231 Figure 91. Synchronous Clock Mode Timing – PLD Table 139. CPLD Macrocell Synchronous Clock Mode Timing (5V PSD Module) Note: 1. Fast Slew Rate output available on PA3-PA0, PB3-PB0, and PD2-PD1. Decrement times by given amount. 2. CLKIN (PD1) tCLCL = tCH + tCL.105 3. Symbol Parameter Conditions Min Max PT Aloc Turbo Off Slew rate(1) Unit fMAX Maximum Frequency External Feedback 1/(tS+tCO) 40.0 MHz Maximum Frequency Internal Feedback (fCNT) 1/(tS+tCO–10) 66.6 MHz Maximum Frequency Pipelined Data 1/(tCH+tCL) 83.3 MHz tS Input Setup Time 12 + 2 + 10 ns tH Input Hold Time 0 ns tCH Clock High Time Clock Input 6 ns tCL Clock Low Time Clock Input 6 ns tCO Clock to Output Delay Clock Input 13 – 2 ns tARD CPLD Array Delay Any macrocell 11 + 2 ns tMIN Minimum Clock Period(2) tCH+tCL 12 ns tCH tCL tCO tS tH CLKIN INPUT REGISTERED OUTPUT AI02860215/231 uPSD33xx Table 140. CPLD Macrocell Synchronous Clock Mode Timing (3V PSD Module) Note: 1. Fast Slew Rate output available on PA3-PA0, PB3-PB0, and PD2-PD1. Decrement times by given amount. 2. CLKIN (PD1) tCLCL = tCH + tCL. Symbol Parameter Conditions Min Max PT Aloc Turbo Off Slew rate(1) Unit fMAX Maximum Frequency External Feedback 1/(tS+tCO) 23.2 MHz Maximum Frequency Internal Feedback (fCNT) 1/(tS+tCO–10) 30.3 MHz Maximum Frequency Pipelined Data 1/(tCH+tCL) 40.0 MHz tS Input Setup Time 20 + 4 + 15 ns tH Input Hold Time 0 ns tCH Clock High Time Clock Input 15 ns tCL Clock Low Time Clock Input 10 ns tCO Clock to Output Delay Clock Input 23 – 6 ns tARD CPLD Array Delay Any macrocell 20 + 4 ns tMIN Minimum Clock Period(2) tCH+tCL 25 nsuPSD33xx 216/231 Figure 92. Asynchronous RESET / Preset Figure 93. Asynchronous Clock Mode Timing (Product Term Clock) Table 141. CPLD Macrocell Asynchronous Clock Mode Timing (5V PSD Module) Symbol Parameter Conditions Min Max PT Aloc Turbo Off Slew Rate Unit fMAXA Maximum Frequency External Feedback 1/(tSA+tCOA) 38.4 MHz Maximum Frequency Internal Feedback (fCNTA) 1/(tSA+tCOA–10) 62.5 MHz Maximum Frequency Pipelined Data 1/(tCHA+tCLA) 71.4 MHz tSA Input Setup Time 7 + 2 + 10 ns tHA Input Hold Time 8 ns tCHA Clock Input High Time 9 + 10 ns tCLA Clock Input Low Time 9 + 10 ns tCOA Clock to Output Delay 21 + 10 – 2 ns tARDA CPLD Array Delay Any macrocell 11 + 2 ns tMINA Minimum Clock Period 1/fCNTA 16 ns tARP REGISTER OUTPUT tARPW RESET/PRESET INPUT AI02864 tCHA tCLA tCOA tSA tHA CLOCK INPUT REGISTERED OUTPUT AI02859217/231 uPSD33xx Table 142. CPLD Macrocell Asynchronous Clock Mode Timing (3V PSD Module) Symbol Parameter Conditions Min Max PT Aloc Turbo Off Slew Rate Unit fMAXA Maximum Frequency External Feedback 1/(tSA+tCOA) 21.7 MHz Maximum Frequency Internal Feedback (fCNTA) 1/(tSA+tCOA–10) 27.8 MHz Maximum Frequency Pipelined Data 1/(tCHA+tCLA) 33.3 MHz tSA Input Setup Time 10 + 4 + 15 ns tHA Input Hold Time 12 ns tCHA Clock High Time 17 + 15 ns tCLA Clock Low Time 13 + 15 ns tCOA Clock to Output Delay 31 + 15 – 6 ns tARD CPLD Array Delay Any macrocell 20 + 4 ns tMINA Minimum Clock Period 1/fCNTA 36 nsuPSD33xx 218/231 Figure 94. Input Macrocell Timing (Product Term Clock) Table 143. Input Macrocell Timing (5V PSD Module) Note: 1. Inputs from Port A, B, and C relative to register/ latch clock from the PLD. ALE/AS latch timings refer to tAVLX and tLXAX. Table 144. Input Macrocell Timing (3V PSD Module) Note: 1. Inputs from Port A, B, and C relative to register/latch clock from the PLD. ALE latch timings refer to tAVLX and tLXAX. Symbol Parameter Conditions Min Max PT Aloc Turbo Off Unit tIS Input Setup Time (Note 1) 0 ns tIH Input Hold Time (Note 1) 15 + 10 ns tINH NIB Input High Time (Note 1) 9 ns tINL NIB Input Low Time (Note 1) 9 ns tINO NIB Input to Combinatorial Delay (Note 1) 34 + 2 + 10 ns Symbol Parameter Conditions Min Max PT Aloc Turbo Off Unit tIS Input Setup Time (Note 1) 0 ns tIH Input Hold Time (Note 1) 25 + 15 ns tINH NIB Input High Time (Note 1) 12 ns tINL NIB Input Low Time (Note 1) 12 ns tINO NIB Input to Combinatorial Delay (Note 1) 43 + 4 + 15 ns tINH tINL tINO tIH tIS PT CLOCK INPUT OUTPUT AI03101219/231 uPSD33xx Table 145. Program, WRITE and Erase Times (5V, 3V PSD Modules) Note: 1. Programmed to all zero before erase. 2. Typical after 100K program/erase cycle is 5 seconds. 3. The polling status, DQ7, is valid tQ7VQV time units before the data byte, DQ0-DQ7, is valid for reading. Symbol Parameter Min. Typ. Max. Unit Flash Program 8.5 s Flash Bulk Erase(1) (pre-programmed) 3(2) 10 s Flash Bulk Erase (not pre-programmed) 5 s tWHQV3 Sector Erase (pre-programmed) 1 10 s tWHQV2 Sector Erase (not pre-programmed) 2.2 s tWHQV1 Byte Program 14 150 µs Program/Erase Cycles (per Sector) 100,000 cycles PLD Program/Erase Cycles 1000 cycles tWHWLO Sector Erase Time-Out 100 µs tQ7VQV DQ7 Valid to Output (DQ7-DQ0) Valid (Data Polling)(3) 30 nsuPSD33xx 220/231 Figure 95. Peripheral I/O READ Timing Table 146. Port A Peripheral Data Mode READ Timing (5V PSD Module) Note: 1. Any input used to select Port A Data Peripheral Mode. 2. Data is already stable on Port A. Table 147. Port A Peripheral Data Mode READ Timing (3V PSD Module) Note: 1. Any input used to select Port A Data Peripheral Mode. 2. Data is already stable on Port A. Symbol Parameter Conditions Min Max Turbo Off Unit tAVQV–PA Address Valid to Data Valid (Note 1) 37 + 10 ns tSLQV–PA CSI Valid to Data Valid 27 + 10 ns tRLQV–PA RD to Data Valid (Note 2) 32 ns tDVQV–PA Data In to Data Out Valid 22 ns tRHQZ–PA RD to Data High-Z 23 ns Symbol Parameter Conditions Min Max Turbo Off Unit tAVQV–PA Address Valid to Data Valid (Note 1) 50 + 20 ns tSLQV–PA CSI Valid to Data Valid 37 + 20 ns tRLQV–PA RD to Data Valid (Note 2) 45 ns tDVQV–PA Data In to Data Out Valid 38 ns tRHQZ–PA RD to Data High-Z 36 ns tRLQV (PA) tDVQV (PA) tRHQZ (PA) tSLQV (PA) tAVQV (PA) ADDRESS DATA VALID ALE A/D BUS RD DATA ON PORT A CSI AI06610221/231 uPSD33xx Figure 96. Peripheral I/O WRITE Timing Table 148. Port A Peripheral Data Mode WRITE Timing (5V PSD Module) Note: 1. Data stable on Port 0 pins to data on Port A. Table 149. Port A Peripheral Data Mode WRITE Timing (3V PSD Module) Note: 1. Data stable on Port 0 pins to data on Port A. Table 150. Supervisor Reset and LVD Note: 1. 25µs minimum to abort a Flash memory program or erase cycle in progress. 2. As FOSC decreases, tRST_ACTV increases. Example: tRST_ACTV = 50ms when FOSC = 8MHz. Symbol Parameter Conditions Min Max Unit tWLQV–PA WR to Data Propagation Delay 25 ns tDVQV–PA Data to Port A Data Propagation Delay (Note 1) 22 ns tWHQZ–PA WR Invalid to Port A Tri-state 20 ns Symbol Parameter Conditions Min Max Unit tWLQV–PA WR to Data Propagation Delay 42 ns tDVQV–PA Data to Port A Data Propagation Delay (Note 1) 38 ns tWHQZ–PA WR Invalid to Port A Tri-state 33 ns Symbol Parameter Conditions Min Typ Max Unit tRST_LO_IN Reset Input Duration 1(1) µs tRST_ACTV Generated Reset Duration fOSC = 40MHz 10(2) ms tRST_FIL Reset Input Spike Filter 1 µs VRST_HYS Reset Input Hysteresis VCC = 3.3V 0.1 V VRST_THRESH LVD Trip Threshold VCC = 3.3V 2.4 2.6 2.8 V tDVQV (PA) tWLQV (PA) tWHQZ (PA) A/D BUS ADDRESS DATA OUT WR PORT A DATA OUT ALE AI06611uPSD33xx 222/231 Table 151. VSTBYON Definitions Timing (5V, 3V PSD Modules) Note: 1. VSTBYON timing is measured at VCC ramp rate of 2ms. Figure 97. ISC Timing Table 152. ISC Timing (5V PSD Module) Note: 1. For non-PLD Programming, Erase or in ISC By-pass Mode. 2. For Program or Erase PLD only. Symbol Parameter Conditions Min Typ Max Unit tBVBH VSTBY Detection to VSTBYON Output High (Note 1) 20 µs tBXBL VSTBY Off Detection to VSTBYON Output Low (Note 1) 20 µs Symbol Parameter Conditions Min Max Unit tISCCF Clock (TCK, PC1) Frequency (except for PLD) (Note 1) 20 MHz tISCCH Clock (TCK, PC1) High Time (except for PLD) (Note 1) 23 ns tISCCL Clock (TCK, PC1) Low Time (except for PLD) (Note 1) 23 ns tISCCFP Clock (TCK, PC1) Frequency (PLD only) (Note 2) 5 MHz tISCCHP Clock (TCK, PC1) High Time (PLD only) (Note 2) 90 ns tISCCLP Clock (TCK, PC1) Low Time (PLD only) (Note 2) 90 ns tISCPSU ISC Port Set Up Time 7 ns tISCPH ISC Port Hold Up Time 5 ns tISCPCO ISC Port Clock to Output 21 ns tISCPZV ISC Port High-Impedance to Valid Output 21 ns tISCPVZ ISC Port Valid Output to High-Impedance 21 ns ISCCH TCK TDI/TMS ISC OUTPUTS/TDO ISC OUTPUTS/TDO t tISCCL tISCPSU tISCPH tISCPVZ t ISCPZV tISCPCO AI02865223/231 uPSD33xx Table 153. ISC Timing (3V PSD Module) Note: 1. For non-PLD Programming, Erase or in ISC By-pass Mode. 2. For Program or Erase PLD only. Figure 98. MCU Module AC Measurement I/O Waveform Note: AC inputs during testing are driven at VCC–0.5V for a logic '1,' and 0.45V for a logic '0.' Timing measurements are made at VIH(min) for a logic '1,' and VIL(max) for a logic '0' Figure 99. PSD Module AC Float I/O Waveform Note: For timing purposes, a Port pin is considered to be no longer floating when a 100mV change from load voltage occurs, and begins to float when a 100mV change from the loaded VOH or VOL level occurs IOL and IOH ≥ 20mA Symbol Parameter Conditions Min Max Unit tISCCF Clock (TCK, PC1) Frequency (except for PLD) (Note 1) 12 MHz tISCCH Clock (TCK, PC1) High Time (except for PLD) (Note 1) 40 ns tISCCL Clock (TCK, PC1) Low Time (except for PLD) (Note 1) 40 ns tISCCFP Clock (TCK, PC1) Frequency (PLD only) (Note 2) 5 MHz tISCCHP Clock (TCK, PC1) High Time (PLD only) (Note 2) 90 ns tISCCLP Clock (TCK, PC1) Low Time (PLD only) (Note 2) 90 ns tISCPSU ISC Port Set Up Time 12 ns tISCPH ISC Port Hold Up Time 5 ns tISCPCO ISC Port Clock to Output 30 ns tISCPZV ISC Port High-Impedance to Valid Output 30 ns tISCPVZ ISC Port Valid Output to High-Impedance 30 ns AI06650 VCC – 0.5V 0.45V Test Points 0.2 VCC – 0.1V 0.2 VCC + 0.9V AI06651 Test Reference Points VOL + 0.1V VOH – 0.1V VLOAD – 0.1V VLOAD + 0.1V 0.2 VCC – 0.1VuPSD33xx 224/231 Figure 100. External Clock Cycle Figure 101. PSD Module AC Measurement I/O Waveform Figure 102. PSD Module AC Measurement Load Circuit Table 154. I/O Pin Capacitance Note: 1. Sampled only, not 100% tested. 2. Typical values are for TA = 25°C and nominal supply voltages. 3. Maximum for MCU Address and Data lines is 20pF each. 3.0V 0V Test Point 1.5V AI03103b Device Under Test 2.01 V 195 Ω CL = 30 pF (Including Scope and Jig Capacitance) AI03104b Symbol Parameter(1) Test Condition Typ.2 Max. Unit CIN Input Capacitance (for input pins) VIN = 0V 4 6 pF COUT Output Capacitance (for input/ output pins)(3) VOUT = 0V 8 12 pF225/231 uPSD33xx PACKAGE MECHANICAL INFORMATION Figure 103. TQFP52 – 52-lead Plastic Thin, Quad, Flat Package Outline Note: Drawing is not to scale. QFP-A Nd E1 CP b e A2 A N A1 α L D1 D 1 Ne E c D2 E2 L1uPSD33xx 226/231 Table 155. TQFP52 – 52-lead Plastic Thin, Quad, Flat Package Mechanical Data Symb mm inches Typ Min Max Typ Min Max A 1.50 – 1.70 0.059 – 0.067 A1 0.10 0.05 0.20 0.004 0.002 0.008 A2 1.40 1.30 1.50 0.055 0.039 0.059 b – 0.20 0.40 – 0.008 0.016 c – 0.07 0.20 – 0.003 0.008 D 12.00 11.80 12.20 0.472 0.465 0.480 D1 10.00 9.80 10.20 0.394 0.386 0.402 D2 7.80 7.67 7.93 0.307 0.302 0.312 E 12.00 11.80 12.20 0.472 0.465 0.480 E1 10.00 9.80 10.20 0.394 0.386 0.402 E2 7.80 7.67 7.93 0.307 0.302 0.312 e 0.65 – – 0.026 – – L – 0.45 0.75 – 0.018 0.030 L1 1.00 – – 0.039 – – α – 0° 7° – 0° 7° n 52 52 Nd 13 13 Ne 13 13 CP – – 0.10 – – 0.004227/231 uPSD33xx Figure 104. TQFP80 – 80-lead Plastic Thin, Quad, Flat Package Outline Note: Drawing is not to scale. QFP-A Nd E1 CP b e A2 A N A1 α L D1 D 1 Ne E c D2 E2 L1uPSD33xx 228/231 Table 156. TQFP80 – 80-lead Plastic Thin, Quad, Flat Package Mechanical Data Symb mm inches Typ Min Max Typ Min Max A 1.60 0.063 A1 0.05 0.15 0.002 0.006 A2 1.40 1.35 1.45 0.055 0.053 0.057 b 0.17 0.27 0.007 0.011 c 0.09 0.20 0.004 0.008 D 14.00 0.551 D1 12.00 0.472 D2 9.50 0.374 E 14.00 0.551 E1 12.00 0.472 E2 9.50 0.374 e 0.50 0.020 L 0.45 0.75 0.018 0.030 L1 1.00 0.039 α 0° 7° 0° 7° n 80 80 Nd 20 20 Ne 20 20 CP 0.08 0.003229/231 uPSD33xx PART NUMBERING Table 157. Ordering Information Scheme For a list of available options (e.g., Speed, Package) or for further information on any aspect of this device, please contact the ST Sales Office nearest to you. Example: uPSD 33 3 4 D V – 40 U 6 T Device Type uPSD = Microcontroller PSD Family 33 = Turbo core SRAM Size 1 = 2Kbyte 3 = 8Kbyte 5 = 32Kbyte Main Flash Memory Size 2 = 64Kbyte 3 = 128Kbyte 4 = 256Kbyte IP Mix D = IP Mix: I2C, SPI, UART (2), IrDA, ADC, Supervisor, PCA Operating Voltage blank = VCC = 4.5 to 5.5V V = VCC = 3.0 to 3.6V Speed –40 = 40MHz Package T = 52-pin TQFP U = 80-pin TQFP Temperature Range 6 = –40 to 85°C Shipping Option Tape & Reel Packing = TuPSD33xx 230/231 REVISION HISTORY Table 158. Document Revision History Date Version Revision Details July 1, 2003 1.0 First Issue 15-Jul-03 1.1 Update register information, electrical characteristics (Table 17, 46, 132, 133, 134, 135; Figure 68) 03-Sep-03 1.2 Update references for Product Catalog 05-Feb-04 2.0 Reformatted; corrected mechanical dimensions (Table 158) 07-May-04 3.0 Reformatted; update characteristics (Figure 3, 4, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84; Table 42, 64, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 121, 129, 130, 131, 136) 14-Sep-04 4.0 Reformatted; updated Feature Summary; added table (Table 128); updated graphics, mechanical dimensions (Figure 3, 4, 37, 40, 51, 76, 80; Table 2, 3, 6, 7, 8, 9, 10, 11, 37, 38, 40, 51, 77, 84, 119, 120, 121, 129, 155, 156) 29-Oct-04 5.0 Corrected TQFP80 mechanical dimensions (Table 156) 21-Jan-05 6.0 Updated characteristics, SPI section (Figure 3, 41, 42, 45; Table 59, 60, 61, 62, 128, 138, 140, 142, 144, 145, 152, 153)231/231 uPSD33xx Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No lii96ns0.71(i96 i)-12.1-s granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 1/29 Revision History : Revision 1.0 (Nov. 02, 2006) -Original Revision 1.1 (Mar. 02, 2007) - Delete BGA ball name of packing dimensions Revision 1.2 (May. 03, 2007) - Modify DC Characteristics Revision 1.3 (May. 14, 2007) - Modify tSS (1.5ns => 2.5ns) and tSH(1ns => 1.5ns) Revision 1.4 (Jul. 10, 2007) - Modify type error ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 2/29 SDRAM 512K x 32Bit x 2Banks Synchronous DRAM FEATURES z 1.8V power supply z LVCMOS compatible with multiplexed address z Dual banks operation z MRS cycle with address key programs - CAS Latency (1, 2 & 3 ) - Burst Length (1, 2, 4, 8 & full page) - Burst Type (Sequential & Interleave) z EMRS cycle with address key programs. z All inputs are sampled at the positive going edge of the system clock z Burst Read Single-bit Write operation z Special Function Support. - PASR (Partial Array Self Refresh ) - TCSR (Temperature compensated Self Refresh) - DS (Driver Strength) z DQM for masking z Auto & self refresh z 64ms refresh period (4K cycle) GENERAL DESCRIPTION The M52D32321A is 33,554,432 bits synchronous high data rate Dynamic RAM organized as 2 x 524,288 words by 32 bits, fabricated with high performance CMOS technology. Synchronous design allows precise cycle control with the use of system clock I/O transactions are possible on every clock cycle. Range of operating frequencies, programmable burst length and programmable latencies allow the same device to be useful for a variety of high bandwidth, high performance memory system applications. ORDERING INFORMATION Part NO. MAX Freq. Package Comments M52D32321A -10BG 100MHz 90 Ball VFBGA Pb-free M52D32321A -7.5BG 133MHz 90 Ball VFBGA Pb-free PIN CONFIGURATION (TOP VIEW) 90 Ball FBGA 1 2 3 4 5 6 7 8 9 A DQ26 DQ24 VSS VDD DQ23 DQ21 B DQ28 VDDQ VSSQ VDDQ VSSQ DQ19 C VSSQ DQ27 DQ25 DQ22 DQ20 VDDQ D VSSQ DQ29 DQ30 DQ17 DQ18 VDDQ E VDDQ DQ31 NC NC DQ16 VSSQ F VSS DQM3 A3 A2 DQM2 VDD G A4 A5 A6 A10 A0 A1 H A7 A8 NC NC NC NC J CLK CKE A9 BA CS RAS K DQM1 NC NC CAS WE DQM0 L VDDQ DQ8 VSS VDD DQ7 VSSQ M VSSQ DQ10 DQ9 DQ6 DQ5 VDDQ N VSSQ DQ12 DQ14 DQ1 DQ3 VDDQ P DQ11 VDDQ VSSQ VDDQ VSSQ DQ4 R DQ13 DQ15 VSS VDD DQ0 DQ2ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 3/29 FUNCTIONAL BLOCK DIAGRAM Bank Select Data Input Register Column Decoder Latency & Burst Length Programming Register 512K x 32 512K x 32 Timing Register CLK CKE CS RAS CAS WE L(U)DQM LDQM LWCBR DQi LDQM LWE LRAS LCBR LWE LCAS CLK ADD LCKE PIN FUNCTION DESCRIPTION Pin Name Input Function CLK System Clock Active on the positive going edge to sample all inputs. CS Chip Select Disables or enables device operation by masking or enabling all inputs except CLK, CKE and L(U)DQM. CKE Clock Enable Masks system clock to freeze operation from the next clock cycle. CKE should be enabled at least one cycle prior to new command. Disable input buffers for power down in standby. A0 ~ A10 Address Row / column addresses are multiplexed on the same pins. Row address : RA0 ~ RA10, column address : CA0 ~ CA7 BA Bank Select Address Selects bank to be activated during row address latch time. Selects bank for read/write during column address latch time. RAS Row Address Strobe Latches row addresses on the positive going edge of the CLK with RAS low. Enables row access & precharge. CAS Column Address Strobe Latches column addresses on the positive going edge of the CLK with CAS low. Enables column access. WE Write Enable Enables write operation and row precharge. Latches data in starting from CAS , WE active. L(U)DQM Data Input / Output Mask Makes data output Hi-Z, tSHZ after the clock and masks the output. Blocks data input when L(U)DQM active. ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 4/29 DQ0 ~ 31 Data Input / Output Data inputs/outputs are multiplexed on the same pins. VDD/VSS Power Supply/Ground Power and ground for the input buffers and the core logic. VDDQ/VSSQ Data Output Power/Ground Isolated power supply and ground for the output buffers to provide improved noise immunity. N.C/RFU No Connection/ Reserved for Future Use This pin is recommended to be left No Connection on the device. ABSOLUTE MAXIMUM RATINGS Parameter Symbol Value Unit Voltage on any pin relative to VSS VIN,VOUT -1.0 ~ 4.6 V Voltage on VDD supply relative to VSS VDD,VDDQ -1.0 ~ 4.6 V Storage temperature TSTG -55 ~ + 150 °C Power dissipation PD 0.7 W Short circuit current IOS 50 MA Note: Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. Functional operation should be restricted to recommended operating condition. Exposure to higher than recommended voltage for extended periods of time could affect device reliability. DC OPERATING CONDITIONS Recommended operating conditions (Voltage referenced to VSS = 0V, TA= 0 °C ~ 70 °C ) Parameter Symbol Min Typ Max Unit Note Supply voltage VDD,VDDQ 1.7 1.8 1.9 V Input logic high voltage VIH 0.8 x VDDQ 1.8 VDDQ+0.3 V 1 Input logic low voltage VIL -0.3 0 0.3 V 2 Output logic high voltage VOH VDDQ – 0.2 - - V IOH =-0.1mA Output logic low voltage VOL - - 0.2 V IOL = 0.1mA Input leakage current IIL -10 - 10 uA 3 Output leakage current IOL -10 - 10 uA 4 Note : 1.VIH (max) = 2.2V AC for pulse width ≤ 3ns acceptable. 2.VIL (min) = -1.0V AC for pulse width ≤ 3ns acceptable. 3.Any input 0V ≤ VIN ≤ VDDQ, all other pins are not under test = 0V. 4.Dout is disabled, 0V ≤ VOUT ≤ VDDQ. CAPACITANCE (VDD = 1.8V, TA = 25 °C , f = 1MHz) Pin Symbol Min Max Unit CLOCK CCLK 2.0 4.0 pF RAS , CAS , WE , CS , CKE, LDQM, UDQM CIN 2.0 4.0 pF ADDRESS CADD 2.0 4.0 pF DQ0 ~DQ15 COUT 3.5 6.0 pF ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 5/29 DC CHARACTERISTICS (Recommended operating condition unless otherwise noted, TA = 0 °C ~ 70 °C ) Version Parameter Symbol Test Condition CAS Latency -7.5 -10 Unit Note Operating Current (One Bank Active) ICC1 Burst Length = 1 tRC ≥ tRC (min), tCC ≥ tCC (min), IOL= 0mA 55 35 mA 1 Precharge Standby ICC2P CKE ≤ VIL(max), tCC =15ns 0.3 mA Current in power-down mode ICC2PS CKE ≤ VIL(max), CLK ≤ VIL(max), tCC = ∞ 0.2 mA ICC2N CKE ≥ VIH(min), CS ≥ VIH(min), tCC =15ns Input signals are changed one time during 30ns 3 mA Precharge Standby Current in non power-down mode ICC2NS CKE ≥ VIH(min), CLK ≤ VIL(max), tCC = ∞ Input signals are stable 1 mA ICC3P CKE ≤ VIL(max), tCC =15ns 1.5 Active Standby Current in power-down mode ICC3PS CKE ≤ VIL(max), CLK ≤ VIL(max), tCC = ∞ 1 mA ICC3N CKE ≥ VIH(min), CS ≥ VIH(min), tCC=15ns Input signals are changed one time during 30ns Active Standby Current 10 mA in non power-down mode (One Bank Active) ICC3NS CKE ≥ VIH (min), CLK ≤ VIL(max), tCC= ∞ Input signals are stable 2.5 mA Operating Current (Burst Mode) ICC4 IOL= 0Ma, Page Burst All Band Activated, tCCD = tCCD (min) 70 60 mA 1 Refresh Current ICC5 tRC ≥ tRC(min) 40 40 mA 2 TCSR range 45 70 °C Self Refresh Current ICC6 CKE ≤ 0.2V 2 Banks 180 200 1 Bank 160 180 uA Deep Power Down Current ICC7 CKE ≤ 0.2V 10 uA Note: 1.Measured with outputs open. Addresses are changed only one time during tCC(min). 2.Refresh period is 64ms. Addresses are changed only one time during tCC(min). ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 6/29 AC OPERATING TEST CONDITIONS (VDD=1.8V ± 0.1V,TA= 0 C° ~ 70 C° ) Parameter Value Unit Input levels (Vih/Vil) 0.9 x VDDQ / 0.2 V Input timing measurement reference level 0.5 x VDDQ V Input rise and fall time tr / tf = 1 / 1 ns Output timing measurement reference level 0.5 x VDDQ V Output load condition See Fig.2 OPERATING AC PARAMETER (AC operating conditions unless otherwise noted) Version Parameter Symbol -7.5 -10 Unit Note Row active to row active delay tRRD(min) 15 20 ns 1 RAS to CAS delay tRCD(min) 22.5 30 ns 1 Row precharge time tRP(min) 22.5 30 ns 1 tRAS(min) 45 50 ns 1 Row active time tRAS(max) 100 us Row cycle time tRC(min) 67.5 90 ns 1 Last data in to new col. Address delay tCDL(min) 1 CLK 2 Last data in to row precharge tRDL(min) 2 CLK 2 Last data in to burst stop tBDL(min) 1 CLK 2 Col. Address to col. Address delay tCCD(min) 1 CLK 3 CAS latency=3 2 Number of valid output data CAS latency=2 1 ea 4 Note: 1. The minimum number of clock cycles is determined by dividing the minimum time required with clock cycle time and then rounding off to the next higher integer. 2. Minimum delay is required to complete write. 3. All parts allow every cycle column address change. 4. In case of row precharge interrupt, auto precharge and read burst stop. The earliest a precharge command can be issued after a Read command without the loss of data is CL+BL-2 clocks. Z0=50 1.8V Output (Fig.2) AC Output Load Circuit 20 pF Vtt =0.5x VDDQ VOH(DC) = VDDQ-0.2V, IOH = -0.1mA VOL(DC) = 0.2V, IOL = 0.1mA 20 pF Output (Fig.1) DC Output Load circuit 10.6K 13.9K 50ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 7/29 AC CHARACTERISTICS (AC operating conditions unless otherwise noted) -7.5 -10 Parameter Symbol Min Max Min Max Unit Note CAS Latency =3 7.5 9 CLK cycle time CAS Latency =2 tCC 12 1000 15 1000 ns 1 CLK to valid CAS Latency =3 - 7 - 8 output delay CAS Latency =2 tSAC - 10 - 10 ns 1 Output data hold time tOH 2.0 - 2.0 - ns 2 CLK high pulse width tCH 2.5 - 2.5 - ns 3 CLK low pulse width tCL 2.5 - 2.5 - ns 3 Input setup time tSS 2.5 - 2.5 - ns 3 Input hold time tSH 1.5 - 1.5 - ns 3 CLK to output in Low-Z tSLZ 1 - 1 - ns 2 CAS Latency =3 - 6 - 7 CLK to output in Hi-Z CAS Latency =2 tSHZ - 9 - 10 ns - *All AC parameters are measured from half to half. Note: 1.Parameters depend on programmed CAS latency. 2.If clock rising time is longer than 1ns,(tr/2-0.5)ns should be added to the parameter. 3.Assumed input rise and fall time (tr & tf)=1ns. If tr & tf is longer than 1ns, transient time compensation should be considered, i.e., [(tr+ tf)/2-1]ns should be added to the parameter. ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 8/29 MODE REGISTER FIELD TABLE TO PROGRAM MODES Register Programmed with MRS Address BA A10/AP A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Function 0 RFU W.B.L TM CAS Latency BT Burst Length Test Mode CAS Latency Burst Type Burst Length A8 A7 Type A6 A5 A4 Latency A3 Type A2 A1 A0 BT = 0 BT = 1 0 0 Mode Register Set 0 0 0 Reserved 0 Sequential 0 0 0 1 1 0 1 Reserved 0 0 1 1 1 Interleave 0 0 1 2 2 1 0 Reserved 0 1 0 2 0 1 0 4 4 1 1 Reserved 0 1 1 3 0 1 1 8 8 1 0 0 Reserved 1 0 0 Reserved Reserved 1 0 1 Reserved 1 0 1 Reserved Reserved 1 1 0 Reserved 1 1 0 Reserved Reserved 1 1 1 Reserved 1 1 1 Full Page Reserved Full Page Length : 256 ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 9/29 Extended Mode Register BA A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Address bus 1 0 ATCSR 0 0 DS TCSR PASR Extended Mode Register A2-0 Self Refresh Coverage 000 Full Array 001 1/2 of Full Array 010 1/4 of Full Array 011 RFU 100 RFU 101 RFU 110 RFU PASR 111 RFU A6-A5 Driver Strength 00 Full Strength 01 1/2 Strength 10 1/4 Strength DS 11 RFU A9 ATCSR ATCSR 0 Enable 1 R TRUTH TABLE (Deep Power Down Mode) COMMAND CKEn-1 CKEn CS RAS CAS WE DQM BA A10/AP A9~A0 Entry H L L H H L X Deep Power Down Mode Exit L H X X X X X X (V= Valid, X= Don’t Care, H= Logic High , L = Logic Low) A4-A3 Maximum Case Temperature 11 85oC 00 70oC 01 45oC TCSR 10 15oC ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 10/29 Burst Length and Sequence (Burst of Two) Starting Address (column address A0 binary) Sequential Addressing Sequence (decimal) Interleave Addressing Sequence (decimal) 0 0,1 0,1 1 1,0 1,0 (Burst of Four) Starting Address (column address A1-A0, binary) Sequential Addressing Sequence (decimal) Interleave Addressing Sequence (decimal) 00 0,1,2,3 0,1,2,3 01 1,2,3,0 1,0,3,2 10 2,3,0,1 2,3,0,1 11 3,0,1,2 3,2,1,0 (Burst of Eight) Starting Address (column address A2-A0, binary) Sequential Addressing Sequence (decimal) Interleave Addressing Sequence (decimal) 000 0,1,2,3,4,5,6,7 0,1,2,3,4,5,6,7 001 1,2,3,4,5,6,7,0 1,0,3,2,5,4,7,6 010 2,3,4,5,6,7,0,1 2,3,0,1,6,7,4,5 011 3,4,5,6,7,0,1,2 3,2,1,0,7,6,5,4 100 4,5,6,7,0,1,2,3 4,5,6,7,0,1,2,3 101 5,6,7,0,1,2,3,4 5,4,7,6,1,0,3,2 110 6,7,0,1,2,3,4,5 6,7,4,5,2,3,0,1 111 7,0,1,2,3,4,5,6 7,6,5,4,3,2,1,0 Full page burst is an extension of the above tables of Sequential Addressing, with the length being 256 for 1Mx32 divice. POWER UP SEQUENCE 1.Apply power and start clock, attempt to maintain CKE= “H”, L(U)DQM = “H” and the other pin are NOP condition at the inputs. 2.Maintain stable power, stable clock and NOP input condition for a minimum of 200us. 3.Issue precharge commands for all banks of the devices. 4.Issue 2 or more auto-refresh commands. 5.Issue mode register set command to initialize the mode register. Cf.)Sequence of 4 & 5 is regardless of the order.ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 11/29 SIMPLIFIED TRUTH TABLE COMMAND CKEn-1 CKEn CS RAS CAS WE DQM BA A10/AP A9~A0 Note Mode Register Set H X L L L L X OP CODE 1,2 Register Extended Mode Register Set H X L L L L X OP CODE 1,2 Auto Refresh H 3 Entry H L L L L H X X 3 L H H H 3 Refresh Self Refresh Exit L H H X X X X X 3 Bank Active & Row Addr. H X L L H H X V Row Address Auto Precharge Disable L 4 Read & Column Address Auto Precharge Enable H X L H L H X V H Column Address (A0~A7) 4,5 Write & Column Auto Precharge Disable L 4 Address Auto Precharge Enable H X L H L L X V H Column Address (A0~A7) 4,5 Burst Stop H X L H H L X X 6 Bank Selection V L 4 Precharge Both Banks H X L L H L X X H X 4 H X X X Entry H L L V V V Clock Suspend or X Active Power Down Exit L H X X X X X X H X X X Entry H L L H H H X H X X X Precharge Power Down Mode Exit L H L V V V X X DQM H X V X 7 H H X X X No Operation Command H X L H H H X X Deep Power Down Mode Entry H L L H H L X Exit L H X X X X X X (V= Valid, X= Don’t Care, H= Logic High , L = Logic Low) Note: 1. OP Code: Operation Code A0~A10/AP, BA: Program keys.(@MRS). BA=0 for MRS and BA=1 for EMRS. 2. MRS/EMRS can be issued only at both banks precharge state. A new command can be issued after 2 clock cycle of MRS. 3. Auto refresh functions are as same as CBR refresh of DRAM. The automatical precharge without row precharge command is meant by “Auto”. Auto / self refresh can be issued only at both banks precharge state. 4. BA: Bank select address. If “Low”: at read, write, row active and precharge, bank A is selected. If “High”: at read, write, row active and precharge, bank B is selected. If A10/AP is “High” at row precharge, BA ignored and both banks are selected. 5. During burst read or write with auto precharge, new read/write command can not be issued. Another bank read /write command can be issued after the end of burst. New row active of the associated bank can be issued at tRP after the end of burst. 6. Burst stop command is valid at every burst length. 7. DQM sampled at positive going edge of a CLK masks the data-in at the very CLK (Write DQM latency is 0), but makes Hi-Z state the data-out of 2 CLK cycles after. (Read DQM latency is 2) ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 12/29 Single Bit Read-Write-Read Cycle (Same Page) @CAS Latency=3, Burst Length=1 : D o n ' t C a r e 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CLOCK CKE C S RAS CAS ADDR W E D Q DQM A10/AP t C H t C L t C C Row Active BA *Note1 HIGH t RCD t S S t S S t S H t S H t S S t S H t S S t S S t S H t S S t S S t S H R a C a C b C c R b BS BS BS BS BS BS R a Qa D b Q c R b Read Write Read Precharge Row Active t R C t RAS t R P t CCD t RAC *Note2 *Note2,3 *Note2,3 *Note4 *Note2 *Note 3 *Note 3 *Note2,3 t S H t SLZ t SAC t O H t S H t S S t S H *Note 3 *Note4ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 13/29 *Note: 1. All inputs expect CKE & DQM can be don’t care when CS is high at the CLK high going edge. 2. Bank active & read/write are controlled by BA. BA Active & Read/Write 0 Bank A 1 Bank B 3.Enable and disable auto precharge function are controlled by A10/AP in read/write command. A10/AP BA Operation 0 0 Disable auto precharge, leave bank A active at end of burst. 1 Disable auto precharge, leave bank B active at end of burst. 1 0 Enable auto precharge, precharge bank A at end of burst. 1 Enable auto precharge, precharge bank B at end of burst. 4.A10/AP and BA control bank precharge when precharge command is asserted. A10/AP BA precharge 0 0 Bank A 0 1 Bank B 1 X Both Banks ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 14/29 Power Up Sequence 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CLOCK CKE ADDR D Q DQM A10/AP t R P Key RAa RAa Precharge All Banks Auto Refresh Auto Refresh Mode Register Set (A-Bank) Row Active : Don't care t R C t R C High level is necessary High level is necessary BA High-Z CS RAS CAS WE Key KeyESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 15/29 Read & Write Cycle at Same Bank @Burst Length = 4 *Note: 1.Minimum row cycle times is required to complete internal DRAM operation. 2.Row precharge can interrupt burst on any cycle. [CAS Latency-1] number of valid output data is available after Row precharge. Last valid output will be Hi-Z(tSHZ) after the clock. 3.Access time from Row active command. tcc*(tRCD +CAS latency-1)+tSAC 4.Ouput will be Hi-Z after the end of burst.(1,2,4,8 bit burst) Burst can’t end in Full Page Mode. tRCD tRC 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CLOCK CKE CS RAS CAS ADDR DQM BA CL=2 CL=3 Ra Rb Cb0 tOH tSAC tSHZ tSHZ tRDL Row Active Read Precharge (A-Bank) (A-Bank) (A-Bank) Precharge (A-Bank) Write (A-Bank) Row Active (A-Bank) *Note3 *Note3 *Note4 *Note4 : Don't care *Note1 Qa0 Qa1 Qa2 Qa3 Db0 Db1 Db2 Db3 Qa0 Qa1 Qa2 Qa3 Db0 Db1 Db2 Db3 tRAC tRAC tRDL Ca0 A10/AP Ra Rb HIGH *Note2 WE tO H QC tSACESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 16/29 Page Read & Write Cycle at Same Bank @ Burst Length=4 *Note :1.To write data before burst read ends, DQM should be asserted three cycle prior to write command to avoid bus contention. 2.Row precharge will interrupt writing. Last data input, tRDL before Row precharge, will be written. 3.DQM should mask invalid input data on precharge command cycle when asserting precharge before end of burst. Input data after Row precharge cycle will be masked internally. CLOCK CKE CS RAS CAS BA ADDR A10/AP CL=2 CL=3 WE DQM HIGH tRCD *Note2 Ra Ca0 Cb0 Cc0 Cd0 Ra Qa0 Qa1 Qb0 Qb1 Qb2 Dc0 Dc1 Dd0 Dd1 Qa0 Qa1 Qb0 Qb1 Dc0 Dc1 Dd0 Dd2 tCDL *Note1 Row Active (A-Bank) Read (A-Bank) Read (A-Bank) Write (A-Bank) Write (A-Bank) Precharge (A-Bank) : Don't care DQ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 tRDL *Note3ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 17/29 Page Read Cycle at Different Bank @ Burst Length=4 *Note: 1. CS can be don’t cared when RAS , CAS and WE are high at the clock high going dege. 2.To interrupt a burst read by row precharge, both the read and the precharge banks must be the same. CLOCK CKE CS RAS CAS BA ADDR A10/AP CL=2 CL=3 WE DQM HIGH *Note2 RAa CAa RBb RAa Read (A-Bank) Row Active Row Active (B-Bank) (A-Bank) Read (A-Bank) Read (B-Bank) Read (A-Bank) Read (B-Bank) Precharge (A-Bank) : Don't care DQ CBb CAc CBd CAe QAa0 *Note1 RBb 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 QAa1 QAa2 QAa3 QBb0 QBb1 QBb2 QBb3 QAc0 QAc1 QBd0 QBd1 QAe0 QAe1 QAa0 QAa1 QAa2 QAa3 QBb0 QBb1 QBb2 QBb3 QAc0 QAc1 QBd0 QBd1 QAe0 QAe1 ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 18/29 Page Write Cycle at Different Bank @Burst Length = 4 *Note: 1.To interrupt burst write by Row precharge, DQM should be asserted to mask invalid input data. 2.To interrupt burst write by row precharge, both the write and the precharge banks must be the same. CLOCK CKE CS RAS CAS BA ADDR A10/AP WE DQM HIGH Row Active (A-Bank) Row Active (B-Bank) Write (A-Bank) Precharge (Both Banks) : Don't care DQ Write (A-Bank) Write (B-Bank) Write (B-Bank) DAa0 DAa1 DAa2 DAa3 DBb0 DBb1 DBb2 DBb3 DAc0 DAc1 DBd0 DBd1 RAa RBb RAa CAa RBb CBb CAc CBd *Note2 tCDL tRDL *Note1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 19/29 Read & Write Cycle at Different Bank @ Burst Length = 4 *Note: 1.tCDL should be met to complete write.ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 20/29 Read & Write Cycle with auto Precharge @ Burst Length =4 *Note: 1.tCDL Should be controlled to meet minimum tRAS before internal precharge start (In the case of Burst Length=1 & 2 and BRSW mode) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CLOCK CKE CAS ADDR W E D Q DQM A10/AP BA CL=2 CL=3 Row Active ( A - Bank ) Row Active ( B - Bank ) Read with Auto Precharge ( A - Bank ) Auto Precharge Start Point (B-Bank) : D o n ' t C a r e Qa0 Qa1 Qa2 Qa3 Db0 Db1 Db2 Db3 R a Ra Ca R b C b R b Qa0 Qa1 Qa2 Qa3 Db0 Db1 Db2 Db3 Write with Auto Precharge (B-Bank) HIGH Auto Precharge Start Point ( A - Bank) C S RASESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 21/29 Clock Suspension & DQM Operation Cycle @CAS Latency=2, Burst Length=4 *Note:1.DQM is needed to prevent bus contention. CLOCK CKE ADDR D Q DQM A10/AP R a C a C b C c R a Qa0 Qa1 Qa2 Qa3 t SHZ Qb0 Qb1 t SHZ Dc0 Dc2 *Note1 Row Active Read Clock Suspension Read Read DQM Write Write DQM Clock Suspension Write DQM :Don't Care BA C S RAS CAS W E 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 22/29 Read Interrupted by Precharge Command & Read Burst Stop Cycle @Burst Length =Full page *Note: 1.Burst can’t end in full page mode, so auto precharge can’t issue. 2.About the valid DQs after burst stop, it is same as the case of RAS interrupt. Both cases are illustrated above timing diagram. See the label 1,2 on them. But at burst write, burst stop and RAS interrupt should be compared carefully. Refer the timing diagram of “Full page write burst stop cycle”. 3.Burst stop is valid at every burst length. CLOCK CKE ADDR D Q DQM A10/AP BA RAa CAa CAb RAa QAa0 QAa1 QAb0 QAb1 QAb2 *Note1 Row Active (A-Bank) Read (A-Bank) Burst Stop Read (A-Bank) :Don't Care HIGH CL=2 CL=3 QAa2 QAa3 QAa4 QAb3 QAb4 QAb5 QAa0 QAa1 QAa2 QAa3 QAa4 QAb0 QAb1 QAb2 QAb3 QAb4 QAb5 1 1 2 2 Precharge (A-Bank) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CS RAS CAS WE *Note2ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 23/29 Write Interrupted by Precharge Command & Write Burst stop Cycle @ Burst Length =Full page *Note: 1. Burst can’t end in full page mode, so auto precharge can’t issue. 2.Data-in at the cycle of interrupted by precharge can not be written into the corresponding memory cell. It is defined by AC parameter of tRDL. DQM at write interrupted by precharge command is needed to prevent invalid write. Input data after Row precharge cycle will be masked internally. 3.Burst stop is valid at every burst length. CLOCK CKE ADDR D Q DQM A10/AP RAa CAa CAb RAa DAa0 DAa1 DAb0 DAb1 DAb2 Row Active (A-Bank) Write (A-Bank) Burst Stop Write (A-Bank) :Don't Care HIGH DAa2 DAa3 DAa4 DAb3 DAb4 DAb5 Precharge (A-Bank) t BDL t RDL *Note2 C S RAS CAS W E BA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 24/29 Burst Read Single bit Write Cycle @Burst Length=2 *Note:1.BRSW modes is enabled by setting A9 “High” at MRS(Mode Register Set). At the BRSW Mode, the burst length at write is fixed to “1” regardless of programmed burst length. 2.When BRSW write command with auto precharge is executed, keep it in mind that tRAS should not be violated. Auto precharge is executed at the next cycle of burst-end, so in the case of BRSW write command, the precharge command will be issued after two clock cycles. CLOCK CKE ADDR CL=2 DQM A10/AP BA RAa RAc RAa QAb0 Row Active (A-Bank) Write (A-Bank) :Don't Care HIGH QAb1 Precharge (A-Bank) CAa RBb CAb CBc CAd RAc DBc0 D Q CL=3 DAa0 QAb0 QAb1 DBc0 Row Active (B-Bank) Row Active (A-Bank) Write with Auto Precharge (B-Bank) Read (A-Bank) DAa0 QAd0 QAd1 QAd0 QAd1 *Note1 C S RAS CAS W E RBb *Note2 Read with Auto Precharge (A-Bank) ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 25/29 Active/Precharge Power Down Mode @CAS Latency=2, Burst Length=4 *Note :1.Both banks should be in idle state prior to entering precharge power down mode. 2.CKE should be set high at least 1CLK+tss prior to Row active command. 3.Can not violate minimum refresh specification. (64ms) CLOCK CKE ADDR D Q DQM A10/AP Active Power-down Exit Precharge : Don't care *Note3 *Note2 *Note1 t S S R a R a Qa0 Qa1 Qa2 t SHZ Precharge Power-Down Entry Precharge Power-Down Exit Row Active Active Power-down Entry Read 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 C a B A RAS CAS C S W E tS S tS SESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 26/29 Self Refresh Entry & Exit Cycle *Note: TO ENTER SELF REFRESH MODE 1. CS , RAS & CAS with CKE should be low at the same clock cycle. 2. After 1 clock cycle, all the inputs including the system clock can be don’t care except for CKE. 3. The device remains in self refresh mode as long as CKE stays “Low”. cf.) Once the device enters self refresh mode, minimum tRAS is required before exit from self refresh. TO EXIT SELF REFRESH MODE 4. System clock restart and be stable before returning CKE high. 5. CS Starts from high. 6. Minimum tRC is required after CKE going high to complete self refresh exit. 7. 4K cycle of burst auto refresh is required before self refresh entry and after self refresh exit if the system uses burst refresh. CLOCK CKE ADDR D Q DQM A10/AP Self Refresh Entry Auto Refresh : Don't care Self Refresh Exit Hi-Z Hi-Z W E BA CAS RAS C S *Note2 *Note1 *Note4 t RCmin *Note6 *Note5 *Note7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 t S S *Note3ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 27/29 Mode Register Set Cycle Auto Refresh Cycle *Both banks precharge should be completed before Mode Register Set cycle and auto refresh cycle. MODE REGISTER SET CYCLE *Note: 1. CS ,RAS , CAS & WE activation at the same clock cycle with address key will set internal mode register. 2.Minimum 2 clock cycles should be met before new RAS activation. 3.Please refer to Mode Register Set table. CLOCK CKE ADDR Key :Don't Care HIGH C S RAS CAS HIGH *Note3 R a *Note1 D Q Hi-Z DQM 1 2 3 4 5 6 0 1 2 3 4 5 6 7 8 9 10 Hi-Z *Note2 t R C MRS New Command Auto Refresh New Command W E 0ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 28/29 PACKING DIMENSIONS 90-BALL SDRAM ( 8x13 mm ) Symbol Dimension in mm Dimension in inch Min Norm Max Min Norm Max A 1.00 0.039 A1 0.30 0.35 0.40 0.012 0.014 0.016 A2 0.586 0.023 øb 0.40 0.45 0.50 0.016 0.018 0.020 D 7.90 8.00 8.10 0.311 0.315 0.319 E 12.90 13.00 13.10 0.508 0.512 0.516 D1 6.40 0.252 E1 11.20 0.441 e 0.80 0.031 Controlling dimension : Millimeter.ESMT M52D32321A Elite Semiconductor Memory Technology Inc. Publication Date : Jul. 2007 Revision : 1.4 29/29 Important Notice All rights reserved. No part of this document may be reproduced or duplicated in any form or by any means without the prior permission of ESMT. The contents contained in this document are believed to be accurate at the time of publication. ESMT assumes no responsibility for any error in this document, and reserves the right to change the products or specification in this document without notice. The information contained herein is presented only as a guide or examples for the application of our products. No responsibility is assumed by ESMT for any infringement of patents, copyrights, or other intellectual property rights of third parties which may result from its use. No license, either express , implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of ESMT or others. Any semiconductor devices may have inherently a certain rate of failure. To minimize risks associated with customer's application, adequate design and operating safeguards against injury, damage, or loss from such failure, should be provided by the customer when making application designs. ESMT's products are not authorized for use in critical applications such as, but not limited to, life support devices or system, where failure or abnormal operation may directly affect human lives or cause physical injury or property damage. If products described here are to be used for such kinds of application, purchaser must do its own quality assurance testing appropriate to such applications. CRUCIAL PART NUMBER MODULE TYPE DENSITY SPEED RANK VOLTAGE COMP CONFIG CAS LATENCY MICRON PART NUMBER CT4G4RFS8213 RDIMM 288-pin 4GB 2133MT/s Single 1.2V 512M x 8 CL15 MTA9ASF51272PZ-2G1A2 CT8G4RFS4213 RDIMM 288-pin 8GB 2133MT/s Single 1.2V 1024M x 4 CL15 MTA18ASF1G72PZ-2G1A2 CT16G4RFD4213 RDIMM 288-pin 16GB 2133MT/s Dual 1.2V 1024M x 4 CL15 MTA36ASF2G72PZ-2G1A2 CT4G4DFS8213 UDIMM 288-pin 4GB 2133MT/s Single 1.2V 512M x 8 CL15 MTA8ATF51264AZ-2G1A1 CT8G4DFD8213 UDIMM 288-pin 8GB 2133MT/s Dual 1.2V 512M x 8 CL15 MTA16ATF1G64AZ-2G1A1 1 Product performance and efficiency improvements are noted as comparisons between DDR3 and DDR4 memory technologies at their introduction. When it was introduced, DDR3-1066 operated at 1.5V and had an estimated component density of 8Gb, compared to DDR4-2133, which will operate at 1.2V and have an estimated component density of 16Gb. When voltage reductions and all other energy-saving DDR4 features are factored in, DDR4 modules are projected to consume up to 40% less power. 2Limited lifetime warranty valid everywhere except Germany and France, where warranty is valid for ten years from date of purchase. 3Program benefits may vary and are subject to change without notice. Customer admittance and continued inclusion to the program is up to the sole discretion of Micron Technology, Inc. REVISION: 04/18/2014 ©2014 Micron Technology, Inc. All rights reserved. Information is subject to change without notice. Crucial and the Crucial logo are trademarks or registered trademarks of Micron Technology, Inc. All other trademarks and service marks are property of their respective owners. Products and specifications are subject to change without notice. Neither Crucial nor Micron Technology is responsible for omissions or errors in typography or photography. NOW SAMPLING: Crucial® DDR4 Server Memory Get early access to Crucial DDR4 modules! Introducing the Crucial DDR4 Technology Enablement Program (TEP) HOW IT WORKS Enroll in the Crucial DDR4 TEP program and get early access to DDR4 modules and information. Start the enrollment process today by visiting www.crucial.com/usa/en/memory-ddr4-info. ELIGIBILITY Channel partners who are currently developing or evaluating DDR4-capable platforms BENEFITS3 • Early access to select Crucial DDR4 modules • Notification of new DDR4 modules as they become available • Access to technical resources to aid in product development and evaluation Now Sampling The following modules are now included as part of the Crucial DDR4 TEP program. Qualified participants are encouraged to inquire about pricing and availability. Additional module types, densities, and speeds will be available later this year. Stay tuned! DDR4 Server Memory: Product Highlights1 • Increase data throughput – up to 50% more memory bandwidth • Enable up to twice the installed server memory capacity • Reduce power consumption – up to 40% more energy efficient • Easier system cooling – less heat generated per module • Optimized for future Intel® Xeon® processor E5-2600 v3 product family • Compatible with OEM servers and warranties • Backed by the Reliance Program • Limited lifetime warranty2 Overcome one of the greatest server limitations: memory. From cloud computing and virtualization to HPC, Big Data and more, memory-dependent server applications require increasingly higher densities of memory and higher levels of performance than are attainable on current DDR3 technology. Enter Crucial DDR4 server memory. More speed. More bandwidth. More efficient. Next generation DDR4 memory is here. © 2007 Microchip Technology Inc. DS39605F PIC18F1220/1320 Data Sheet 18/20/28-Pin High-Performance, Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt TechnologyDS39605F-page ii © 2007 Microchip Technology Inc. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Linear Active Thermistor, Mindi, MiWi, MPASM, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, rfPICDEM, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2007, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. • Microchip is willing to work with the customer who is concerned about the integrity of their code. • Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.” Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona, Gresham, Oregon and Mountain View, California. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.© 2007 Microchip Technology Inc. DS39605F-page 1 Low-Power Features: • Power Managed modes: - Run: CPU on, peripherals on - Idle: CPU off, peripherals on - Sleep: CPU off, peripherals off • Power Consumption modes: - PRI_RUN: 150 μA, 1 MHz, 2V - PRI_IDLE: 37 μA, 1 MHz, 2V - SEC_RUN: 14 μA, 32 kHz, 2V - SEC_IDLE: 5.8 μA, 32 kHz, 2V - RC_RUN: 110 μA, 1 MHz, 2V - RC_IDLE: 52 μA, 1 MHz, 2V - Sleep: 0.1 μA, 1 MHz, 2V • Timer1 Oscillator: 1.1 μA, 32 kHz, 2V • Watchdog Timer: 2.1 μA • Two-Speed Oscillator Start-up Oscillators: • Four Crystal modes: - LP, XT, HS: up to 25 MHz - HSPLL: 4-10 MHz (16-40 MHz internal) • Two External RC modes, up to 4 MHz • Two External Clock modes, up to 40 MHz • Internal oscillator block: - 8 user-selectable frequencies: 31 kHz, 125 kHz, 250 kHz, 500 kHz, 1 MHz, 2 MHz, 4 MHz, 8 MHz - 125 kHz to 8 MHz calibrated to 1% - Two modes select one or two I/O pins - OSCTUNE – Allows user to shift frequency • Secondary oscillator using Timer1 @ 32 kHz • Fail-Safe Clock Monitor - Allows for safe shutdown if peripheral clock stops Peripheral Highlights: • High current sink/source 25 mA/25 mA • Three external interrupts • Enhanced Capture/Compare/PWM (ECCP) module: - One, two or four PWM outputs - Selectable polarity - Programmable dead time - Auto-Shutdown and Auto-Restart - Capture is 16-bit, max resolution 6.25 ns (TCY/16) - Compare is 16-bit, max resolution 100 ns (TCY) • Compatible 10-bit, up to 13-channel Analog-toDigital Converter module (A/D) with programmable acquisition time • Enhanced USART module: - Supports RS-485, RS-232 and LIN 1.2 - Auto-Wake-up on Start bit - Auto-Baud Detect Special Microcontroller Features: • 100,000 erase/write cycle Enhanced Flash program memory typical • 1,000,000 erase/write cycle Data EEPROM memory typical • Flash/Data EEPROM Retention: > 40 years • Self-programmable under software control • Priority levels for interrupts • 8 x 8 Single-Cycle Hardware Multiplier • Extended Watchdog Timer (WDT): - Programmable period from 41 ms to 131s - 2% stability over VDD and Temperature • Single-supply 5V In-Circuit Serial Programming™ (ICSP™) via two pins • In-Circuit Debug (ICD) via two pins • Wide operating voltage range: 2.0V to 5.5V Device Program Memory Data Memory I/O 10-bit A/D (ch) ECCP (PWM) EUSART Timers Flash 8/16-bit (bytes) # Single-Word Instructions SRAM (bytes) EEPROM (bytes) PIC18F1220 4K 2048 256 256 16 7 1 Y 1/3 PIC18F1320 8K 4096 256 256 16 7 1 Y 1/3 18/20/28-Pin High-Performance, Enhanced Flash MCUs with 10-bit A/D and nanoWatt Technology PIC18F1220/1320PIC18F1220/1320 DS39605F-page 2 © 2007 Microchip Technology Inc. Pin Diagrams RB3/CCP1/P1A RB2/P1B/INT2 OSC1/CLKI/RA7 OSC2/CLKO/RA6 VDD/AVDD RB7/PGD/T1OSI/ RB6/PGC/T1OSO/ RB5/PGM/KBI1 RB4/AN6/RX/ RA0/AN0 RA1/AN1/LVDIN RA4/T0CKI MCLR/VPP/RA5 VSS/AVSS RA2/AN2/VREFRA3/AN3/VREF+ RB0/AN4/INT0 RB1/AN5/TX/ 1 2 3 4 5 6 7 8 9 18 17 16 15 14 13 12 11 10 PIC18F1X20 18-Pin PDIP, SOIC RB3/CCP1/P1A RB2/P1B/INT2 OSC1/CLKI/RA7 OSC2/CLKO/RA6 VDD RB7/PGD/T1OSI/ RB6/PGC/T1OSO/ RB5/PGM/KBI1 RB4/AN6/RX/ RA0/AN0 RA1/AN1/LVDIN RA4/T0CKI MCLR/VPP/RA5 VSS RA2/AN2/VREFRA3/AN3/VREF+ RB0/AN4/INT0 RB1/AN5/TX/ 1 2 3 4 5 7 8 9 10 20 19 18 17 16 14 13 12 11 PIC18F1X20 AVSS 6 15 AVDD 20-Pin SSOP 28-Pin QFN 16 2 RA4/T0CKI RA0/AN0 NC MCLR/VPP/RA5 NC AVSS NC RA2/AN2/VREFRA3/AN3/VREF+ RA1/AN1/LVDIN OSC1/CLKI/RA7 OSC2/CLKO/RA6 VDD NC AVDD RB7/PGD/T1OSI/P1D/KBI3 RB6/PGC/T1OSO/T13CKI/P1C/KBI2 NC RB5/PGM/KBI1 7 PIC18F1X20 1 3 6 5 4 15 21 19 20 17 18 28 27 26 25 24 23 22 8 9 10 11 12 13 14 VSS NC NC RB2/P1B/INT2 RB0/AN4/INT0 RB1/AN5/TX/CK/INT1 NC RB4/AN6/RX/DT/KBI0 RB3/CCP1/P1A T13CKI/P1C/KBI2 P1D/KBI3 CK/INT1 DT/KBI0 P1D/KBI3 T13CKI/P1C/KBI2 CK/INT1 DT/KBI0© 2007 Microchip Technology Inc. DS39605F-page 3 PIC18F1220/1320 Table of Contents 1.0 Device Overview .......................................................................................................................................................................... 5 2.0 Oscillator Configurations ............................................................................................................................................................ 11 3.0 Power Managed Modes ............................................................................................................................................................. 19 4.0 Reset.......................................................................................................................................................................................... 33 5.0 Memory Organization................................................................................................................................................................. 41 6.0 Flash Program Memory.............................................................................................................................................................. 57 7.0 Data EEPROM Memory ............................................................................................................................................................. 67 8.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 71 9.0 Interrupts .................................................................................................................................................................................... 73 10.0 I/O Ports ..................................................................................................................................................................................... 87 11.0 Timer0 Module ........................................................................................................................................................................... 99 12.0 Timer1 Module ......................................................................................................................................................................... 103 13.0 Timer2 Module ......................................................................................................................................................................... 109 14.0 Timer3 Module ......................................................................................................................................................................... 111 15.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 115 16.0 Enhanced Addressable Universal Synchronous Asynchronous Receiver Transmitter (EUSART) .......................................... 131 17.0 10-Bit Analog-to-Digital Converter (A/D) Module ..................................................................................................................... 155 18.0 Low-Voltage Detect.................................................................................................................................................................. 165 19.0 Special Features of the CPU.................................................................................................................................................... 171 20.0 Instruction Set Summary.......................................................................................................................................................... 191 21.0 Development Support............................................................................................................................................................... 233 22.0 Electrical Characteristics.......................................................................................................................................................... 237 23.0 DC and AC Characteristics Graphs and Tables....................................................................................................................... 267 24.0 Packaging Information.............................................................................................................................................................. 285 Appendix A: Revision History............................................................................................................................................................. 291 Appendix B: Device Differences ........................................................................................................................................................ 291 Appendix C: Conversion Considerations ........................................................................................................................................... 292 Appendix D: Migration from Baseline to Enhanced Devices.............................................................................................................. 292 Appendix E: Migration from Mid-Range to Enhanced Devices .......................................................................................................... 293 Appendix F: Migration from High-End to Enhanced Devices............................................................................................................. 293 Index .................................................................................................................................................................................................. 295 The Microchip Web Site..................................................................................................................................................................... 303 Customer Change Notification Service .............................................................................................................................................. 303 Customer Support.............................................................................................................................................................................. 303 Reader Response .............................................................................................................................................................................. 304 PIC18F1220/1320 Product Identification System .............................................................................................................................. 305PIC18F1220/1320 DS39605F-page 4 © 2007 Microchip Technology Inc. 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DS39605F-page 5 PIC18F1220/1320 1.0 DEVICE OVERVIEW This document contains device specific information for the following devices: This family offers the advantages of all PIC18 microcontrollers – namely, high computational performance at an economical price – with the addition of high endurance Enhanced Flash program memory. On top of these features, the PIC18F1220/1320 family introduces design enhancements that make these microcontrollers a logical choice for many high-performance, power sensitive applications. 1.1 New Core Features 1.1.1 nanoWatt TECHNOLOGY All of the devices in the PIC18F1220/1320 family incorporate a range of features that can significantly reduce power consumption during operation. Key items include: • Alternate Run Modes: By clocking the controller from the Timer1 source or the internal oscillator block, power consumption during code execution can be reduced by as much as 90%. • Multiple Idle Modes: The controller can also run with its CPU core disabled, but the peripherals are still active. In these states, power consumption can be reduced even further, to as little as 4% of normal operation requirements. • On-the-fly Mode Switching: The power managed modes are invoked by user code during operation, allowing the user to incorporate power-saving ideas into their application’s software design. • Lower Consumption in Key Modules: The power requirements for both Timer1 and the Watchdog Timer have been reduced by up to 80%, with typical values of 1.1 and 2.1 μA, respectively. 1.1.2 MULTIPLE OSCILLATOR OPTIONS AND FEATURES All of the devices in the PIC18F1220/1320 family offer nine different oscillator options, allowing users a wide range of choices in developing application hardware. These include: • Four Crystal modes, using crystals or ceramic resonators. • Two External Clock modes, offering the option of using two pins (oscillator input and a divide-by-4 clock output), or one pin (oscillator input, with the second pin reassigned as general I/O). • Two External RC Oscillator modes, with the same pin options as the External Clock modes. • An internal oscillator block, which provides an 8 MHz clock (±2% accuracy) and an INTRC source (approximately 31 kHz, stable over temperature and VDD), as well as a range of 6 user-selectable clock frequencies (from 125 kHz to 4 MHz) for a total of 8 clock frequencies. Besides its availability as a clock source, the internal oscillator block provides a stable reference source that gives the family additional features for robust operation: • Fail-Safe Clock Monitor: This option constantly monitors the main clock source against a reference signal provided by the internal oscillator. If a clock failure occurs, the controller is switched to the internal oscillator block, allowing for continued low-speed operation, or a safe application shutdown. • Two-Speed Start-up: This option allows the internal oscillator to serve as the clock source from Poweron Reset, or wake-up from Sleep mode, until the primary clock source is available. This allows for code execution during what would otherwise be the clock start-up interval and can even allow an application to perform routine background activities and return to Sleep without returning to full power operation. 1.2 Other Special Features • Memory Endurance: The Enhanced Flash cells for both program memory and data EEPROM are rated to last for many thousands of erase/write cycles – up to 100,000 for program memory and 1,000,000 for EEPROM. Data retention without refresh is conservatively estimated to be greater than 40 years. • Self-programmability: These devices can write to their own program memory spaces under internal software control. By using a bootloader routine located in the protected Boot Block at the top of program memory, it becomes possible to create an application that can update itself in the field. • Enhanced CCP module: In PWM mode, this module provides 1, 2 or 4 modulated outputs for controlling half-bridge and full-bridge drivers. Other features include auto-shutdown, for disabling PWM outputs on interrupt or other select conditions and auto-restart, to reactivate outputs once the condition has cleared. • Enhanced USART: This serial communication module features automatic wake-up on Start bit and automatic baud rate detection and supports RS-232, RS-485 and LIN 1.2 protocols, making it ideally suited for use in Local Interconnect Network (LIN) bus applications. • 10-bit A/D Converter: This module incorporates programmable acquisition time, allowing for a channel to be selected and a conversion to be initiated without waiting for a sampling period and thus, reduce code overhead. • Extended Watchdog Timer (WDT): This enhanced version incorporates a 16-bit prescaler, allowing a time-out range from 4 ms to over 2 minutes that is stable across operating voltage and temperature. • PIC18F1220 • PIC18F1320PIC18F1220/1320 DS39605F-page 6 © 2007 Microchip Technology Inc. 1.3 Details on Individual Family Members Devices in the PIC18F1220/1320 family are available in 18-pin, 20-pin and 28-pin packages. A block diagram for this device family is shown in Figure 1-1. The devices are differentiated from each other only in the amount of on-chip Flash program memory (4 Kbytes for the PIC18F1220 device, 8 Kbytes for the PIC18F1320 device). These and other features are summarized in Table 1-1. A block diagram of the PIC18F1220/1320 device architecture is provided in Figure 1-1. The pinouts for this device family are listed in Table 1-2. TABLE 1-1: DEVICE FEATURES Features PIC18F1220 PIC18F1320 Operating Frequency DC – 40 MHz DC – 40 MHz Program Memory (Bytes) 4096 8192 Program Memory (Instructions) 2048 4096 Data Memory (Bytes) 256 256 Data EEPROM Memory (Bytes) 256 256 Interrupt Sources 15 15 I/O Ports Ports A, B Ports A, B Timers 4 4 Enhanced Capture/Compare/PWM Modules 1 1 Serial Communications Enhanced USART Enhanced USART 10-bit Analog-to-Digital Module 7 input channels 7 input channels Resets (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST), MCLR (optional), WDT POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST), MCLR (optional), WDT Programmable Low-Voltage Detect Yes Yes Programmable Brown-out Reset Yes Yes Instruction Set 75 Instructions 75 Instructions Packages 18-pin SDIP 18-pin SOIC 20-pin SSOP 28-pin QFN 18-pin SDIP 18-pin SOIC 20-pin SSOP 28-pin QFN© 2007 Microchip Technology Inc. DS39605F-page 7 PIC18F1220/1320 FIGURE 1-1: PIC18F1220/1320 BLOCK DIAGRAM Instruction Decode & Control PORTA PORTB RA4/T0CKI MCLR/VPP/RA5(1) Enhanced Timer0 Timer1 Timer2 RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1/LVDIN RA0/AN0 Data Latch Data RAM Address Latch Address<12> 12(2) BSR FSR0 FSR1 FSR2 4 12 4 PCH PCL PCLATH 8 31 Level Stack Program Counter PRODH PRODL 8 x 8 Multiply WREG 8 BIT OP 8 8 ALU<8> 8 Address Latch (8 Kbytes) Data Latch 20 21 21 16 8 8 8 inc/dec logic 21 8 Data Bus<8> 8 Instruction 12 3 ROM Latch Timer3 Bank0, F PCLATU PCU OSC2/CLKO/RA6(2) USART 8 Register Table Latch Table Pointer <2> inc/dec logic RB0/AN4/INT0 RB4/AN6/RX/DT/KBI0 RB1/AN5/TX/CK/INT1 RB2/P1B/INT2 RB3/CCP1/P1A RB5/PGM/KBI1 RB6/PGC/T1OSO/ RB7/PGD/T1OSI/ OSC2/CLKI/RA7 Decode (2) Power-up Timer Power-on Reset Watchdog Timer VDD, VSS Brown-out Reset Precision Reference Voltage Low-Voltage Programming In-Circuit Debugger Oscillator Start-up Timer Timing Generation OSC1(2) OSC2(2) T1OSI T1OSO INTRC Oscillator Fail-Safe Clock Monitor Note 1: RA5 is available only when the MCLR Reset is disabled. 2: OSC1, OSC2, CLKI and CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O. Refer to Section 2.0 “Oscillator Configurations” for additional information. 8 CCP Enhanced T13CKI/P1C/KBI2 Program Memory (4 Kbytes) PIC18F1220 PIC18F1320 A/D Converter Data EEPROM P1D/KBI3 MCLR(1)PIC18F1220/1320 DS39605F-page 8 © 2007 Microchip Technology Inc. TABLE 1-2: PIC18F1220/1320 PINOUT I/O DESCRIPTIONS Pin Name Pin Number Pin Type Buffer Type Description PDIP/ SOIC SSOP QFN MCLR/VPP/RA5 MCLR VPP RA5 441 I P I ST — ST Master Clear (input) or programming voltage (input). Master Clear (Reset) input. This pin is an active-low Reset to the device. Programming voltage input. Digital input. OSC1/CLKI/RA7 OSC1 CLKI RA7 16 18 21 I I I/O ST CMOS ST Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) General purpose I/O pin. OSC2/CLKO/RA6 OSC2 CLKO RA6 15 17 20 O O I/O — — ST Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC, EC and INTRC modes, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes instruction cycle rate. General purpose I/O pin. PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 1 1 26 I/O I ST Analog Digital I/O. Analog input 0. RA1/AN1/LVDIN RA1 AN1 LVDIN 2 2 27 I/O I I ST Analog Analog Digital I/O. Analog input 1. Low-Voltage Detect input. RA2/AN2/VREFRA2 AN2 VREF- 677 I/O I I ST Analog Analog Digital I/O. Analog input 2. A/D reference voltage (low) input. RA3/AN3/VREF+ RA3 AN3 VREF+ 788 I/O I I ST Analog Analog Digital I/O. Analog input 3. A/D reference voltage (high) input. RA4/T0CKI RA4 T0CKI 3 3 28 I/O I ST/OD ST Digital I/O. Open-drain when configured as output. Timer0 external clock input. RA5 See the MCLR/VPP/RA5 pin. RA6 See the OSC2/CLKO/RA6 pin. RA7 See the OSC1/CLKI/RA7 pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open-drain (no P diode to VDD) © 2007 Microchip Technology Inc. DS39605F-page 9 PIC18F1220/1320 PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/AN4/INT0 RB0 AN4 INT0 899 I/O I I TTL Analog ST Digital I/O. Analog input 4. External interrupt 0. RB1/AN5/TX/CK/INT1 RB1 AN5 TX CK INT1 9 10 10 I/O I O I/O I TTL Analog — ST ST Digital I/O. Analog input 5. EUSART asynchronous transmit. EUSART synchronous clock (see related RX/DT). External interrupt 1. RB2/P1B/INT2 RB2 P1B INT2 17 19 23 I/O O I TTL — ST Digital I/O. Enhanced CCP1/PWM output. External interrupt 2. RB3/CCP1/P1A RB3 CCP1 P1A 18 20 24 I/O I/O O TTL ST — Digital I/O. Capture 1 input/Compare 1 output/PWM 1 output. Enhanced CCP1/PWM output. RB4/AN6/RX/DT/KBI0 RB4 AN6 RX DT KBI0 10 11 12 I/O I I I/O I TTL Analog ST ST TTL Digital I/O. Analog input 6. EUSART asynchronous receive. EUSART synchronous data (see related TX/CK). Interrupt-on-change pin. RB5/PGM/KBI1 RB5 PGM KBI1 11 12 13 I/O I/O I TTL ST TTL Digital I/O. Low-Voltage ICSP Programming enable pin. Interrupt-on-change pin. RB6/PGC/T1OSO/ T13CKI/P1C/KBI2 RB6 PGC T1OSO T13CKI P1C KBI2 12 13 15 I/O I/O O I O I TTL ST — ST — TTL Digital I/O. In-Circuit Debugger and ICSP programming clock pin. Timer1 oscillator output. Timer1/Timer3 external clock output. Enhanced CCP1/PWM output. Interrupt-on-change pin. RB7/PGD/T1OSI/ P1D/KBI3 RB7 PGD T1OSI P1D KBI3 13 14 16 I/O I/O I O I TTL ST CMOS — TTL Digital I/O. In-Circuit Debugger and ICSP programming data pin. Timer1 oscillator input. Enhanced CCP1/PWM output. Interrupt-on-change pin. VSS 5 5, 6 3, 5 P — Ground reference for logic and I/O pins. VDD 14 15, 16 17, 19 P — Positive supply for logic and I/O pins. NC — — 18 — — No connect. TABLE 1-2: PIC18F1220/1320 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description PDIP/ SOIC SSOP QFN Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open-drain (no P diode to VDD) PIC18F1220/1320 DS39605F-page 10 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 11 PIC18F1220/1320 2.0 OSCILLATOR CONFIGURATIONS 2.1 Oscillator Types The PIC18F1220 and PIC18F1320 devices can be operated in ten different oscillator modes. The user can program the configuration bits, FOSC3:FOSC0, in Configuration Register 1H to select one of these ten modes: 1. LP Low-Power Crystal 2. XT Crystal/Resonator 3. HS High-Speed Crystal/Resonator 4. HSPLL High-Speed Crystal/Resonator with PLL enabled 5. RC External Resistor/Capacitor with FOSC/4 output on RA6 6. RCIO External Resistor/Capacitor with I/O on RA6 7. INTIO1 Internal Oscillator with FOSC/4 output on RA6 and I/O on RA7 8. INTIO2 Internal Oscillator with I/O on RA6 and RA7 9. EC External Clock with FOSC/4 output 10. ECIO External Clock with I/O on RA6 2.2 Crystal Oscillator/Ceramic Resonators In XT, LP, HS or HSPLL Oscillator modes, a crystal or ceramic resonator is connected to the OSC1 and OSC2 pins to establish oscillation. Figure 2-1 shows the pin connections. The oscillator design requires the use of a parallel cut crystal. FIGURE 2-1: CRYSTAL/CERAMIC RESONATOR OPERATION (XT, LP, HS OR HSPLL CONFIGURATION) TABLE 2-1: CAPACITOR SELECTION FOR CERAMIC RESONATORS Note: Use of a series cut crystal may give a frequency out of the crystal manufacturer’s specifications. Typical Capacitor Values Used: Mode Freq OSC1 OSC2 XT 455 kHz 2.0 MHz 4.0 MHz 56 pF 47 pF 33 pF 56 pF 47 pF 33 pF HS 8.0 MHz 16.0 MHz 27 pF 22 pF 27 pF 22 pF Capacitor values are for design guidance only. These capacitors were tested with the resonators listed below for basic start-up and operation. These values are not optimized. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. See the notes following Table 2-2 for additional information. Resonators Used: 455 kHz 4.0 MHz 2.0 MHz 8.0 MHz 16.0 MHz Note 1: See Table 2-1 and Table 2-2 for initial values of C1 and C2. 2: A series resistor (RS) may be required for AT strip cut crystals. 3: RF varies with the oscillator mode chosen. C1(1) C2(1) XTAL OSC2 OSC1 RF(3) Sleep To Logic PIC18FXXXX RS(2) InternalPIC18F1220/1320 DS39605F-page 12 © 2007 Microchip Technology Inc. TABLE 2-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR An external clock source may also be connected to the OSC1 pin in the HS mode, as shown in Figure 2-2. FIGURE 2-2: EXTERNAL CLOCK INPUT OPERATION (HS OSC CONFIGURATION) 2.3 HSPLL A Phase Locked Loop (PLL) circuit is provided as an option for users who wish to use a lower frequency crystal oscillator circuit, or to clock the device up to its highest rated frequency from a crystal oscillator. This may be useful for customers who are concerned with EMI due to high-frequency crystals. The HSPLL mode makes use of the HS mode oscillator for frequencies up to 10 MHz. A PLL then multiplies the oscillator output frequency by 4 to produce an internal clock frequency up to 40 MHz. The PLL is enabled only when the oscillator configuration bits are programmed for HSPLL mode. If programmed for any other mode, the PLL is not enabled. FIGURE 2-3: PLL BLOCK DIAGRAM Osc Type Crystal Freq Typical Capacitor Values Tested: C1 C2 LP 32 kHz 33 pF 33 pF 200 kHz 15 pF 15 pF XT 1 MHz 33 pF 33 pF 4 MHz 27 pF 27 pF HS 4 MHz 27 pF 27 pF 8 MHz 22 pF 22 pF 20 MHz 15 pF 15 pF Capacitor values are for design guidance only. These capacitors were tested with the crystals listed below for basic start-up and operation. These values are not optimized. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. See the notes following this table for additional information. Crystals Used: 32 kHz 4 MHz 200 kHz 8 MHz 1 MHz 20 MHz Note 1: Higher capacitance increases the stability of oscillator, but also increases the start-up time. 2: When operating below 3V VDD, or when using certain ceramic resonators at any voltage, it may be necessary to use the HS mode or switch to a crystal oscillator. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: RS may be required to avoid overdriving crystals with low drive level specification. 5: Always verify oscillator performance over the VDD and temperature range that is expected for the application. OSC1 Open OSC2 Clock from Ext. System PIC18FXXXX (HS Mode) MUX VCO Loop Filter Crystal Osc OSC2 OSC1 PLL Enable FIN FOUT SYSCLK Phase Comparator HS Oscillator Enable ÷4 (from Configuration Register 1H)© 2007 Microchip Technology Inc. DS39605F-page 13 PIC18F1220/1320 2.4 External Clock Input The EC and ECIO Oscillator modes require an external clock source to be connected to the OSC1 pin. There is no oscillator start-up time required after a Power-on Reset, or after an exit from Sleep mode. In the EC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes, or to synchronize other logic. Figure 2-4 shows the pin connections for the EC Oscillator mode. FIGURE 2-4: EXTERNAL CLOCK INPUT OPERATION (EC CONFIGURATION) The ECIO Oscillator mode functions like the EC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). Figure 2-5 shows the pin connections for the ECIO Oscillator mode. FIGURE 2-5: EXTERNAL CLOCK INPUT OPERATION (ECIO CONFIGURATION) 2.5 RC Oscillator For timing insensitive applications, the “RC” and “RCIO” device options offer additional cost savings. The RC oscillator frequency is a function of the supply voltage, the resistor (REXT) and capacitor (CEXT) values and the operating temperature. In addition to this, the oscillator frequency will vary from unit to unit due to normal manufacturing variation. Furthermore, the difference in lead frame capacitance between package types will also affect the oscillation frequency, especially for low CEXT values. The user also needs to take into account variation, due to tolerance of external R and C components used. Figure 2-6 shows how the R/C combination is connected. In the RC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes, or to synchronize other logic. FIGURE 2-6: RC OSCILLATOR MODE The RCIO Oscillator mode (Figure 2-7) functions like the RC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). FIGURE 2-7: RCIO OSCILLATOR MODE OSC1/CLKI FOSC/4 OSC2/CLKO Clock from Ext. System PIC18FXXXX OSC1/CLKI RA6 I/O (OSC2) Clock from Ext. System PIC18FXXXX OSC2/CLKO CEXT REXT PIC18FXXXX OSC1 FOSC/4 Internal Clock VDD VSS Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ CEXT > 20 pF CEXT REXT PIC18FXXXX OSC1 Internal Clock VDD VSS Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ CEXT > 20 pF RA6 I/O (OSC2)PIC18F1220/1320 DS39605F-page 14 © 2007 Microchip Technology Inc. 2.6 Internal Oscillator Block The PIC18F1220/1320 devices include an internal oscillator block, which generates two different clock signals; either can be used as the system’s clock source. This can eliminate the need for external oscillator circuits on the OSC1 and/or OSC2 pins. The main output (INTOSC) is an 8 MHz clock source, which can be used to directly drive the system clock. It also drives a postscaler, which can provide a range of clock frequencies from 125 kHz to 4 MHz. The INTOSC output is enabled when a system clock frequency from 125 kHz to 8 MHz is selected. The other clock source is the internal RC oscillator (INTRC), which provides a 31 kHz output. The INTRC oscillator is enabled by selecting the internal oscillator block as the system clock source, or when any of the following are enabled: • Power-up Timer • Fail-Safe Clock Monitor • Watchdog Timer • Two-Speed Start-up These features are discussed in greater detail in Section 19.0 “Special Features of the CPU”. The clock source frequency (INTOSC direct, INTRC direct or INTOSC postscaler) is selected by configuring the IRCF bits of the OSCCON register (Register 2-2). 2.6.1 INTIO MODES Using the internal oscillator as the clock source can eliminate the need for up to two external oscillator pins, which can then be used for digital I/O. Two distinct configurations are available: • In INTIO1 mode, the OSC2 pin outputs FOSC/4, while OSC1 functions as RA7 for digital input and output. • In INTIO2 mode, OSC1 functions as RA7 and OSC2 functions as RA6, both for digital input and output. 2.6.2 INTRC OUTPUT FREQUENCY The internal oscillator block is calibrated at the factory to produce an INTOSC output frequency of 8.0 MHz (see Table 22-6). This changes the frequency of the INTRC source from its nominal 31.25 kHz. Peripherals and features that depend on the INTRC source will be affected by this shift in frequency. Once set during factory calibration, the INTRC frequency will remain within ±2% as temperature and VDD change across their full specified operating ranges. 2.6.3 OSCTUNE REGISTER The internal oscillator’s output has been calibrated at the factory, but can be adjusted in the user’s application. This is done by writing to the OSCTUNE register (Register 2-1). The tuning sensitivity is constant throughout the tuning range. When the OSCTUNE register is modified, the INTOSC and INTRC frequencies will begin shifting to the new frequency. The INTRC clock will reach the new frequency within 8 clock cycles (approximately 8 * 32 μs = 256 μs). The INTOSC clock will stabilize within 1 ms. Code execution continues during this shift. There is no indication that the shift has occurred. Operation of features that depend on the INTRC clock source frequency, such as the WDT, Fail-Safe Clock Monitor and peripherals, will also be affected by the change in frequency.© 2007 Microchip Technology Inc. DS39605F-page 15 PIC18F1220/1320 REGISTER 2-1: OSCTUNE: OSCILLATOR TUNING REGISTER 2.7 Clock Sources and Oscillator Switching Like previous PIC18 devices, the PIC18F1220/1320 devices include a feature that allows the system clock source to be switched from the main oscillator to an alternate low-frequency clock source. PIC18F1220/ 1320 devices offer two alternate clock sources. When enabled, these give additional options for switching to the various power managed operating modes. Essentially, there are three clock sources for these devices: • Primary oscillators • Secondary oscillators • Internal oscillator block The primary oscillators include the External Crystal and Resonator modes, the External RC modes, the External Clock modes and the internal oscillator block. The particular mode is defined on POR by the contents of Configuration Register 1H. The details of these modes are covered earlier in this chapter. The secondary oscillators are those external sources not connected to the OSC1 or OSC2 pins. These sources may continue to operate even after the controller is placed in a power managed mode. PIC18F1220/1320 devices offer only the Timer1 oscillator as a secondary oscillator. This oscillator, in all power managed modes, is often the time base for functions such as a real-time clock. Most often, a 32.768 kHz watch crystal is connected between the RB6/T1OSO and RB7/T1OSI pins. Like the LP mode oscillator circuit, loading capacitors are also connected from each pin to ground. These pins are also used during ICSP operations. The Timer1 oscillator is discussed in greater detail in Section 12.2 “Timer1 Oscillator”. In addition to being a primary clock source, the internal oscillator block is available as a power managed mode clock source. The INTRC source is also used as the clock source for several special features, such as the WDT and Fail-Safe Clock Monitor. The clock sources for the PIC18F1220/1320 devices are shown in Figure 2-8. See Section 12.0 “Timer1 Module” for further details of the Timer1 oscillator. See Section 19.1 “Configuration Bits” for configuration register details. U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 bit 7 bit 0 bit 7-6 Unimplemented: Read as ‘0’ bit 5-0 TUN<5:0>: Frequency Tuning bits 011111 = Maximum frequency • • • • 000001 000000 = Center frequency. Oscillator module is running at the calibrated frequency. 111111 • • • • 100000 = Minimum frequency Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 16 © 2007 Microchip Technology Inc. 2.7.1 OSCILLATOR CONTROL REGISTER The OSCCON register (Register 2-2) controls several aspects of the system clock’s operation, both in full power operation and in power managed modes. The System Clock Select bits, SCS1:SCS0, select the clock source that is used when the device is operating in power managed modes. The available clock sources are the primary clock (defined in Configuration Register 1H), the secondary clock (Timer1 oscillator) and the internal oscillator block. The clock selection has no effect until a SLEEP instruction is executed and the device enters a power managed mode of operation. The SCS bits are cleared on all forms of Reset. The Internal Oscillator Select bits, IRCF2:IRCF0, select the frequency output of the internal oscillator block that is used to drive the system clock. The choices are the INTRC source, the INTOSC source (8 MHz), or one of the six frequencies derived from the INTOSC postscaler (125 kHz to 4 MHz). If the internal oscillator block is supplying the system clock, changing the states of these bits will have an immediate change on the internal oscillator’s output. The OSTS, IOFS and T1RUN bits indicate which clock source is currently providing the system clock. The OSTS indicates that the Oscillator Start-up Timer has timed out and the primary clock is providing the system clock in Primary Clock modes. The IOFS bit indicates when the internal oscillator block has stabilized and is providing the system clock in RC Clock modes or during Two-Speed Start-ups. The T1RUN bit (T1CON<6>) indicates when the Timer1 oscillator is providing the system clock in Secondary Clock modes. In power managed modes, only one of these three bits will be set at any time. If none of these bits are set, the INTRC is providing the system clock, or the internal oscillator block has just started and is not yet stable. The IDLEN bit controls the selective shutdown of the controller’s CPU in power managed modes. The uses of these bits are discussed in more detail in Section 3.0 “Power Managed Modes”. FIGURE 2-8: PIC18F1220/1320 CLOCK DIAGRAM Note 1: The Timer1 oscillator must be enabled to select the secondary clock source. The Timer1 oscillator is enabled by setting the T1OSCEN bit in the Timer1 Control register (T1CON<3>). If the Timer1 oscillator is not enabled, then any attempt to select a secondary clock source when executing a SLEEP instruction will be ignored. 2: It is recommended that the Timer1 oscillator be operating and stable before executing the SLEEP instruction or a very long delay may occur while the Timer1 oscillator starts. PIC18F1220/1320 4 x PLL CONFIG1H <3:0> Secondary Oscillator T1OSCEN Enable Oscillator T1OSO T1OSI Clock Source Option for Other Modules OSC1 OSC2 Sleep Primary Oscillator HSPLL LP, XT, HS, RC, EC T1OSC CPU Peripherals IDLEN Postscaler MUX MUX 8 4 MHz 2 MHz 1 MHz 500 kHz 125 kHz 250 kHz OSCCON<6:4> 111 110 101 100 011 010 001 000 31 kHz INTRC Source Internal Oscillator Block WDT, FSCM 8 MHz Internal Oscillator (INTOSC) OSCCON<6:4> Clock Control OSCCON<1:0>© 2007 Microchip Technology Inc. DS39605F-page 17 PIC18F1220/1320 REGISTER 2-2: OSCCON REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R(1) R-0 R/W-0 R/W-0 IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 bit 7 bit 0 bit 7 IDLEN: Idle Enable bits 1 = Idle mode enabled; CPU core is not clocked in power managed modes 0 = Run mode enabled; CPU core is clocked in Run modes, but not Sleep mode bit 6-4 IRCF2:IRCF0: Internal Oscillator Frequency Select bits 111 = 8 MHz (8 MHz source drives clock directly) 110 = 4 MHz 101 = 2 MHz 100 = 1 MHz 011 = 500 kHz 010 = 250 kHz 001 = 125 kHz 000 = 31 kHz (INTRC source drives clock directly) bit 3 OSTS: Oscillator Start-up Time-out Status bit 1 = Oscillator Start-up Timer time-out has expired; primary oscillator is running 0 = Oscillator Start-up Timer time-out is running; primary oscillator is not ready bit 2 IOFS: INTOSC Frequency Stable bit 1 = INTOSC frequency is stable 0 = INTOSC frequency is not stable bit 1-0 SCS1:SCS0: System Clock Select bits 1x = Internal oscillator block (RC modes) 01 = Timer1 oscillator (Secondary modes) 00 = Primary oscillator (Sleep and PRI_IDLE modes) Note 1: Depends on state of the IESO bit in Configuration Register 1H. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 18 © 2007 Microchip Technology Inc. 2.7.2 OSCILLATOR TRANSITIONS The PIC18F1220/1320 devices contain circuitry to prevent clocking “glitches” when switching between clock sources. A short pause in the system clock occurs during the clock switch. The length of this pause is between 8 and 9 clock periods of the new clock source. This ensures that the new clock source is stable and that its pulse width will not be less than the shortest pulse width of the two clock sources. Clock transitions are discussed in greater detail in Section 3.1.2 “Entering Power Managed Modes”. 2.8 Effects of Power Managed Modes on the Various Clock Sources When the device executes a SLEEP instruction, the system is switched to one of the power managed modes, depending on the state of the IDLEN and SCS1:SCS0 bits of the OSCCON register. See Section 3.0 “Power Managed Modes” for details. When PRI_IDLE mode is selected, the designated primary oscillator continues to run without interruption. For all other power managed modes, the oscillator using the OSC1 pin is disabled. The OSC1 pin (and OSC2 pin, if used by the oscillator) will stop oscillating. In Secondary Clock modes (SEC_RUN and SEC_IDLE), the Timer1 oscillator is operating and providing the system clock. The Timer1 oscillator may also run in all power managed modes if required to clock Timer1 or Timer3. In Internal Oscillator modes (RC_RUN and RC_IDLE), the internal oscillator block provides the system clock source. The INTRC output can be used directly to provide the system clock and may be enabled to support various special features, regardless of the power managed mode (see Section 19.2 “Watchdog Timer (WDT)” through Section 19.4 “Fail-Safe Clock Monitor”). The INTOSC output at 8 MHz may be used directly to clock the system, or may be divided down first. The INTOSC output is disabled if the system clock is provided directly from the INTRC output. If the Sleep mode is selected, all clock sources are stopped. Since all the transistor switching currents have been stopped, Sleep mode achieves the lowest current consumption of the device (only leakage currents). Enabling any on-chip feature that will operate during Sleep will increase the current consumed during Sleep. The INTRC is required to support WDT operation. The Timer1 oscillator may be operating to support a realtime clock. Other features may be operating that do not require a system clock source (i.e., INTn pins, A/D conversions and others). 2.9 Power-up Delays Power-up delays are controlled by two timers, so that no external Reset circuitry is required for most applications. The delays ensure that the device is kept in Reset until the device power supply is stable under normal circumstances and the primary clock is operating and stable. For additional information on power-up delays, see Sections 4.1 through 4.5. The first timer is the Power-up Timer (PWRT), which provides a fixed delay on power-up (parameter 33, Table 22-8) if enabled in Configuration Register 2L. The second timer is the Oscillator Start-up Timer (OST), intended to keep the chip in Reset until the crystal oscillator is stable (LP, XT and HS modes). The OST does this by counting 1024 oscillator cycles before allowing the oscillator to clock the device. When the HSPLL Oscillator mode is selected, the device is kept in Reset for an additional 2 ms following the HS mode OST delay, so the PLL can lock to the incoming clock frequency. There is a delay of 5 to 10 μs following POR while the controller becomes ready to execute instructions. This delay runs concurrently with any other delays. This may be the only delay that occurs when any of the EC, RC or INTIO modes are used as the primary clock source. TABLE 2-3: OSC1 AND OSC2 PIN STATES IN SLEEP MODE Oscillator Mode OSC1 Pin OSC2 Pin RC, INTIO1 Floating, external resistor should pull high At logic low (clock/4 output) RCIO, INTIO2 Floating, external resistor should pull high Configured as PORTA, bit 6 ECIO Floating, pulled by external clock Configured as PORTA, bit 6 EC Floating, pulled by external clock At logic low (clock/4 output) LP, XT and HS Feedback inverter disabled at quiescent voltage level Feedback inverter disabled at quiescent voltage level Note: See Table 4-1 in Section 4.0 “Reset” for time-outs due to Sleep and MCLR Reset.© 2007 Microchip Technology Inc. DS39605F-page 19 PIC18F1220/1320 3.0 POWER MANAGED MODES The PIC18F1220/1320 devices offer a total of six operating modes for more efficient power management (see Table 3-1). These provide a variety of options for selective power conservation in applications where resources may be limited (i.e., battery powered devices). There are three categories of power managed modes: • Sleep mode • Idle modes • Run modes These categories define which portions of the device are clocked and sometimes, what speed. The Run and Idle modes may use any of the three available clock sources (primary, secondary or INTOSC multiplexer); the Sleep mode does not use a clock source. The clock switching feature offered in other PIC18 devices (i.e., using the Timer1 oscillator in place of the primary oscillator) and the Sleep mode offered by all PIC® devices (where all system clocks are stopped) are both offered in the PIC18F1220/1320 devices (SEC_RUN and Sleep modes, respectively). However, additional power managed modes are available that allow the user greater flexibility in determining what portions of the device are operating. The power managed modes are event driven; that is, some specific event must occur for the device to enter or (more particularly) exit these operating modes. For PIC18F1220/1320 devices, the power managed modes are invoked by using the existing SLEEP instruction. All modes exit to PRI_RUN mode when triggered by an interrupt, a Reset or a WDT time-out (PRI_RUN mode is the normal full power execution mode; the CPU and peripherals are clocked by the primary oscillator source). In addition, power managed Run modes may also exit to Sleep mode, or their corresponding Idle mode. 3.1 Selecting Power Managed Modes Selecting a power managed mode requires deciding if the CPU is to be clocked or not and selecting a clock source. The IDLEN bit controls CPU clocking, while the SCS1:SCS0 bits select a clock source. The individual modes, bit settings, clock sources and affected modules are summarized in Table 3-1. 3.1.1 CLOCK SOURCES The clock source is selected by setting the SCS bits of the OSCCON register (Register 2-2). Three clock sources are available for use in power managed Idle modes: the primary clock (as configured in Configuration Register 1H), the secondary clock (Timer1 oscillator) and the internal oscillator block. The secondary and internal oscillator block sources are available for the power managed modes (PRI_RUN mode is the normal full power execution mode; the CPU and peripherals are clocked by the primary oscillator source). TABLE 3-1: POWER MANAGED MODES Mode OSCCON Bits Module Clocking Available Clock and Oscillator Source IDLEN <7> SCS1:SCS0 <1:0> CPU Peripherals Sleep 0 00 Off Off None – All clocks are disabled PRI_RUN 0 00 Clocked Clocked Primary – LP, XT, HS, HSPLL, RC, EC, INTRC(1) This is the normal full power execution mode. SEC_RUN 0 01 Clocked Clocked Secondary – Timer1 Oscillator RC_RUN 0 1x Clocked Clocked Internal Oscillator Block(1) PRI_IDLE 1 00 Off Clocked Primary – LP, XT, HS, HSPLL, RC, EC SEC_IDLE 1 01 Off Clocked Secondary – Timer1 Oscillator RC_IDLE 1 1x Off Clocked Internal Oscillator Block(1) Note 1: Includes INTOSC and INTOSC postscaler, as well as the INTRC source.PIC18F1220/1320 DS39605F-page 20 © 2007 Microchip Technology Inc. 3.1.2 ENTERING POWER MANAGED MODES In general, entry, exit and switching between power managed clock sources requires clock source switching. In each case, the sequence of events is the same. Any change in the power managed mode begins with loading the OSCCON register and executing a SLEEP instruction. The SCS1:SCS0 bits select one of three power managed clock sources; the primary clock (as defined in Configuration Register 1H), the secondary clock (the Timer1 oscillator) and the internal oscillator block (used in RC modes). Modifying the SCS bits will have no effect until a SLEEP instruction is executed. Entry to the power managed mode is triggered by the execution of a SLEEP instruction. Figure 3-5 shows how the system is clocked while switching from the primary clock to the Timer1 oscillator. When the SLEEP instruction is executed, clocks to the device are stopped at the beginning of the next instruction cycle. Eight clock cycles from the new clock source are counted to synchronize with the new clock source. After eight clock pulses from the new clock source are counted, clocks from the new clock source resume clocking the system. The actual length of the pause is between eight and nine clock periods from the new clock source. This ensures that the new clock source is stable and that its pulse width will not be less than the shortest pulse width of the two clock sources. Three bits indicate the current clock source: OSTS and IOFS in the OSCCON register and T1RUN in the T1CON register. Only one of these bits will be set while in a power managed mode. When the OSTS bit is set, the primary clock is providing the system clock. When the IOFS bit is set, the INTOSC output is providing a stable 8 MHz clock source and is providing the system clock. When the T1RUN bit is set, the Timer1 oscillator is providing the system clock. If none of these bits are set, then either the INTRC clock source is clocking the system, or the INTOSC source is not yet stable. If the internal oscillator block is configured as the primary clock source in Configuration Register 1H, then both the OSTS and IOFS bits may be set when in PRI_RUN or PRI_IDLE modes. This indicates that the primary clock (INTOSC output) is generating a stable 8 MHz output. Entering an RC power managed mode (same frequency) would clear the OSTS bit. 3.1.3 MULTIPLE SLEEP COMMANDS The power managed mode that is invoked with the SLEEP instruction is determined by the settings of the IDLEN and SCS bits at the time the instruction is executed. If another SLEEP instruction is executed, the device will enter the power managed mode specified by these same bits at that time. If the bits have changed, the device will enter the new power managed mode specified by the new bit settings. 3.1.4 COMPARISONS BETWEEN RUN AND IDLE MODES Clock source selection for the Run modes is identical to the corresponding Idle modes. When a SLEEP instruction is executed, the SCS bits in the OSCCON register are used to switch to a different clock source. As a result, if there is a change of clock source at the time a SLEEP instruction is executed, a clock switch will occur. In Idle modes, the CPU is not clocked and is not running. In Run modes, the CPU is clocked and executing code. This difference modifies the operation of the WDT when it times out. In Idle modes, a WDT time-out results in a wake from power managed modes. In Run modes, a WDT time-out results in a WDT Reset (see Table 3-2). During a wake-up from an Idle mode, the CPU starts executing code by entering the corresponding Run mode until the primary clock becomes ready. When the primary clock becomes ready, the clock source is automatically switched to the primary clock. The IDLEN and SCS bits are unchanged during and after the wake-up. Figure 3-2 shows how the system is clocked during the clock source switch. The example assumes the device was in SEC_IDLE or SEC_RUN mode when a wake is triggered (the primary clock was configured in HSPLL mode). Note 1: Caution should be used when modifying a single IRCF bit. If VDD is less than 3V, it is possible to select a higher clock speed than is supported by the low VDD. Improper device operation may result if the VDD/FOSC specifications are violated. 2: Executing a SLEEP instruction does not necessarily place the device into Sleep mode; executing a SLEEP instruction is simply a trigger to place the controller into a power managed mode selected by the OSCCON register, one of which is Sleep mode.© 2007 Microchip Technology Inc. DS39605F-page 21 PIC18F1220/1320 3.2 Sleep Mode The power managed Sleep mode in the PIC18F1220/ 1320 devices is identical to that offered in all other PIC microcontrollers. It is entered by clearing the IDLEN and SCS1:SCS0 bits (this is the Reset state) and executing the SLEEP instruction. This shuts down the primary oscillator and the OSTS bit is cleared (see Figure 3-1). When a wake event occurs in Sleep mode (by interrupt, Reset or WDT time-out), the system will not be clocked until the primary clock source becomes ready (see Figure 3-2), or it will be clocked from the internal oscillator block if either the Two-Speed Start-up or the Fail-Safe Clock Monitor are enabled (see Section 19.0 “Special Features of the CPU”). In either case, the OSTS bit is set when the primary clock is providing the system clocks. The IDLEN and SCS bits are not affected by the wake-up. 3.3 Idle Modes The IDLEN bit allows the microcontroller’s CPU to be selectively shut down while the peripherals continue to operate. Clearing IDLEN allows the CPU to be clocked. Setting IDLEN disables clocks to the CPU, effectively stopping program execution (see Register 2-2). The peripherals continue to be clocked regardless of the setting of the IDLEN bit. There is one exception to how the IDLEN bit functions. When all the low-power OSCCON bits are cleared (IDLEN:SCS1:SCS0 = 000), the device enters Sleep mode upon the execution of the SLEEP instruction. This is both the Reset state of the OSCCON register and the setting that selects Sleep mode. This maintains compatibility with other PIC devices that do not offer power managed modes. If the Idle Enable bit, IDLEN (OSCCON<7>), is set to a ‘1’ when a SLEEP instruction is executed, the peripherals will be clocked from the clock source selected using the SCS1:SCS0 bits; however, the CPU will not be clocked. Since the CPU is not executing instructions, the only exits from any of the Idle modes are by interrupt, WDT time-out or a Reset. When a wake event occurs, CPU execution is delayed approximately 10 μs while it becomes ready to execute code. When the CPU begins executing code, it is clocked by the same clock source as was selected in the power managed mode (i.e., when waking from RC_IDLE mode, the internal oscillator block will clock the CPU and peripherals until the primary clock source becomes ready – this is essentially RC_RUN mode). This continues until the primary clock source becomes ready. When the primary clock becomes ready, the OSTS bit is set and the system clock source is switched to the primary clock (see Figure 3-4). The IDLEN and SCS bits are not affected by the wake-up. While in any Idle mode or the Sleep mode, a WDT time-out will result in a WDT wake-up to full power operation. TABLE 3-2: COMPARISON BETWEEN POWER MANAGED MODES Power Managed Mode CPU is Clocked by ... WDT Time-out causes a ... Peripherals are Clocked by ... Clock during Wake-up (while primary becomes ready) Sleep Not clocked (not running) Wake-up Not clocked None or INTOSC multiplexer if Two-Speed Start-up or Fail-Safe Clock Monitor are enabled Any Idle mode Not clocked (not running) Wake-up Primary, Secondary or INTOSC multiplexer Unchanged from Idle mode (CPU operates as in corresponding Run mode) Any Run mode Primary or secondary clocks or INTOSC multiplexer Reset Primary or secondary clocks or INTOSC multiplexer Unchanged from Run modePIC18F1220/1320 DS39605F-page 22 © 2007 Microchip Technology Inc. FIGURE 3-1: TIMING TRANSITION FOR ENTRY TO SLEEP MODE FIGURE 3-2: TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL) Q2 Q3 Q4 OSC1 Peripheral Sleep Program Q1 Q1 Counter Clock CPU Clock PC PC + 2 Q3 Q4 Q1 Q2 OSC1 Peripheral Program PC PLL Clock Q3 Q4 Output CPU Clock Q1 Q2 Q3 Q4 Q1 Q2 Clock Counter PC + 6 PC + 8 Q1 Q2 Q3 Q4 Wake Event Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. TOST(1) TPLL(1) OSTS bit Set PC + 2 PC + 4© 2007 Microchip Technology Inc. DS39605F-page 23 PIC18F1220/1320 3.3.1 PRI_IDLE MODE This mode is unique among the three Low-Power Idle modes, in that it does not disable the primary system clock. For timing sensitive applications, this allows for the fastest resumption of device operation with its more accurate primary clock source, since the clock source does not have to “warm up” or transition from another oscillator. PRI_IDLE mode is entered by setting the IDLEN bit, clearing the SCS bits and executing a SLEEP instruction. Although the CPU is disabled, the peripherals continue to be clocked from the primary clock source specified in Configuration Register 1H. The OSTS bit remains set in PRI_IDLE mode (see Figure 3-3). When a wake event occurs, the CPU is clocked from the primary clock source. A delay of approximately 10 μs is required between the wake event and code execution starts. This is required to allow the CPU to become ready to execute instructions. After the wakeup, the OSTS bit remains set. The IDLEN and SCS bits are not affected by the wake-up (see Figure 3-4). FIGURE 3-3: TRANSITION TIMING TO PRI_IDLE MODE FIGURE 3-4: TRANSITION TIMING FOR WAKE FROM PRI_IDLE MODE Q1 Peripheral Program PC PC + 2 OSC1 Q3 Q4 Q1 CPU Clock Clock Counter Q2 OSC1 Peripheral Program PC CPU Clock PC + 2 Q1 Q3 Q4 Clock Counter Q2 Wake Event CPU Start-up DelayPIC18F1220/1320 DS39605F-page 24 © 2007 Microchip Technology Inc. 3.3.2 SEC_IDLE MODE In SEC_IDLE mode, the CPU is disabled, but the peripherals continue to be clocked from the Timer1 oscillator. This mode is entered by setting the Idle bit, modifying bits, SCS1:SCS0 = 01 and executing a SLEEP instruction. When the clock source is switched (see Figure 3-5) to the Timer1 oscillator, the primary oscillator is shut down, the OSTS bit is cleared and the T1RUN bit is set. When a wake event occurs, the peripherals continue to be clocked from the Timer1 oscillator. After a 10 μs delay following the wake event, the CPU begins executing code, being clocked by the Timer1 oscillator. The microcontroller operates in SEC_RUN mode until the primary clock becomes ready. When the primary clock becomes ready, a clock switchback to the primary clock occurs (see Figure 3-6). When the clock switch is complete, the T1RUN bit is cleared, the OSTS bit is set and the primary clock is providing the system clock. The IDLEN and SCS bits are not affected by the wake-up. The Timer1 oscillator continues to run. FIGURE 3-5: TIMING TRANSITION FOR ENTRY TO SEC_IDLE MODE FIGURE 3-6: TIMING TRANSITION FOR WAKE FROM SEC_RUN MODE (HSPLL) Note: The Timer1 oscillator should already be running prior to entering SEC_IDLE mode. If the T1OSCEN bit is not set when the SLEEP instruction is executed, the SLEEP instruction will be ignored and entry to SEC_IDLE mode will not occur. If the Timer1 oscillator is enabled, but not yet running, peripheral clocks will be delayed until the oscillator has started; in such situations, initial oscillator operation is far from stable and unpredictable operation may result. Q2 Q3 Q4 OSC1 Peripheral Program Q1 T1OSI Q1 Counter Clock CPU Clock PC PC + 2 12345678 Clock Transition Q1 Q3 Q4 OSC1 Peripheral Program PC PC + 2 T1OSI PLL Clock Q1 PC + 6 Q2 Output Q3 Q4 Q1 CPU Clock PC + 4 Clock Counter Q2 Q2 Q3 Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. Wake from Interrupt Event TPLL(1) 1 2 3 45678 Clock Transition OSTS bit Set TOST(1)© 2007 Microchip Technology Inc. DS39605F-page 25 PIC18F1220/1320 3.3.3 RC_IDLE MODE In RC_IDLE mode, the CPU is disabled, but the peripherals continue to be clocked from the internal oscillator block using the INTOSC multiplexer. This mode allows for controllable power conservation during Idle periods. This mode is entered by setting the IDLEN bit, setting SCS1 (SCS0 is ignored) and executing a SLEEP instruction. The INTOSC multiplexer may be used to select a higher clock frequency by modifying the IRCF bits before executing the SLEEP instruction. When the clock source is switched to the INTOSC multiplexer (see Figure 3-7), the primary oscillator is shut down and the OSTS bit is cleared. If the IRCF bits are set to a non-zero value (thus, enabling the INTOSC output), the IOFS bit becomes set after the INTOSC output becomes stable, in about 1 ms. Clocks to the peripherals continue while the INTOSC source stabilizes. If the IRCF bits were previously at a non-zero value before the SLEEP instruction was executed and the INTOSC source was already stable, the IOFS bit will remain set. If the IRCF bits are all clear, the INTOSC output is not enabled and the IOFS bit will remain clear; there will be no indication of the current clock source. When a wake event occurs, the peripherals continue to be clocked from the INTOSC multiplexer. After a 10 μs delay following the wake event, the CPU begins executing code, being clocked by the INTOSC multiplexer. The microcontroller operates in RC_RUN mode until the primary clock becomes ready. When the primary clock becomes ready, a clock switchback to the primary clock occurs (see Figure 3-8). When the clock switch is complete, the IOFS bit is cleared, the OSTS bit is set and the primary clock is providing the system clock. The IDLEN and SCS bits are not affected by the wakeup. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. FIGURE 3-7: TIMING TRANSITION TO RC_IDLE MODE FIGURE 3-8: TIMING TRANSITION FOR WAKE FROM RC_RUN MODE (RC_RUN TO PRI_RUN) Q2 Q3 Q4 OSC1 Peripheral Program Q1 INTRC Q1 Counter Clock CPU Clock PC PC + 2 12345678 Clock Transition Q1 Q3 Q4 OSC1 Peripheral Program PC PC + 2 INTOSC PLL Clock Q1 PC + 6 Q2 Output Q3 Q4 Q1 CPU Clock PC + 4 Clock Counter Q2 Q2 Q3 Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. Wake from Interrupt Event TOST(1) TPLL(1) 12345678 Clock Transition OSTS bit Set Multiplexer Q4PIC18F1220/1320 DS39605F-page 26 © 2007 Microchip Technology Inc. 3.4 Run Modes If the IDLEN bit is clear when a SLEEP instruction is executed, the CPU and peripherals are both clocked from the source selected using the SCS1:SCS0 bits. While these operating modes may not afford the power conservation of Idle or Sleep modes, they do allow the device to continue executing instructions by using a lower frequency clock source. RC_RUN mode also offers the possibility of executing code at a frequency greater than the primary clock. Wake-up from a power managed Run mode can be triggered by an interrupt, or any Reset, to return to full power operation. As the CPU is executing code in Run modes, several additional exits from Run modes are possible. They include exit to Sleep mode, exit to a corresponding Idle mode and exit by executing a RESET instruction. While the device is in any of the power managed Run modes, a WDT time-out will result in a WDT Reset. 3.4.1 PRI_RUN MODE The PRI_RUN mode is the normal full power execution mode. If the SLEEP instruction is never executed, the microcontroller operates in this mode (a SLEEP instruction is executed to enter all other power managed modes). All other power managed modes exit to PRI_RUN mode when an interrupt or WDT time-out occur. There is no entry to PRI_RUN mode. The OSTS bit is set. The IOFS bit may be set if the internal oscillator block is the primary clock source (see Section 2.7.1 “Oscillator Control Register”). 3.4.2 SEC_RUN MODE The SEC_RUN mode is the compatible mode to the “clock switching” feature offered in other PIC18 devices. In this mode, the CPU and peripherals are clocked from the Timer1 oscillator. This gives users the option of lower power consumption while still using a high accuracy clock source. SEC_RUN mode is entered by clearing the IDLEN bit, setting SCS1:SCS0 = 01 and executing a SLEEP instruction. The system clock source is switched to the Timer1 oscillator (see Figure 3-9), the primary oscillator is shut down, the T1RUN bit (T1CON<6>) is set and the OSTS bit is cleared. When a wake event occurs, the peripherals and CPU continue to be clocked from the Timer1 oscillator while the primary clock is started. When the primary clock becomes ready, a clock switchback to the primary clock occurs (see Figure 3-6). When the clock switch is complete, the T1RUN bit is cleared, the OSTS bit is set and the primary clock is providing the system clock. The IDLEN and SCS bits are not affected by the wake-up. The Timer1 oscillator continues to run. Firmware can force an exit from SEC_RUN mode. By clearing the T1OSCEN bit (T1CON<3>), an exit from SEC_RUN back to normal full power operation is triggered. The Timer1 oscillator will continue to run and provide the system clock, even though the T1OSCEN bit is cleared. The primary clock is started. When the primary clock becomes ready, a clock switchback to the primary clock occurs (see Figure 3-6). When the clock switch is complete, the Timer1 oscillator is disabled, the T1RUN bit is cleared, the OSTS bit is set and the primary clock is providing the system clock. The IDLEN and SCS bits are not affected by the wake-up. FIGURE 3-9: TIMING TRANSITION FOR ENTRY TO SEC_RUN MODE Note: The Timer1 oscillator should already be running prior to entering SEC_RUN mode. If the T1OSCEN bit is not set when the SLEEP instruction is executed, the SLEEP instruction will be ignored and entry to SEC_RUN mode will not occur. If the Timer1 oscillator is enabled, but not yet running, system clocks will be delayed until the oscillator has started; in such situations, initial oscillator operation is far from stable and unpredictable operation may result. Q2 Q3 Q4 OSC1 Peripheral Program Q1 T1OSI Q1 Counter Clock CPU Clock PC PC + 2 12345678 Clock Transition Q2 Q3 Q4 Q1 Q2 Q3 PC + 2© 2007 Microchip Technology Inc. DS39605F-page 27 PIC18F1220/1320 3.4.3 RC_RUN MODE In RC_RUN mode, the CPU and peripherals are clocked from the internal oscillator block using the INTOSC multiplexer and the primary clock is shut down. When using the INTRC source, this mode provides the best power conservation of all the Run modes, while still executing code. It works well for user applications which are not highly timing sensitive, or do not require high-speed clocks at all times. If the primary clock source is the internal oscillator block (either of the INTIO1 or INTIO2 oscillators), there are no distinguishable differences between PRI_RUN and RC_RUN modes during execution. However, a clock switch delay will occur during entry to and exit from RC_RUN mode. Therefore, if the primary clock source is the internal oscillator block, the use of RC_RUN mode is not recommended. This mode is entered by clearing the IDLEN bit, setting SCS1 (SCS0 is ignored) and executing a SLEEP instruction. The IRCF bits may select the clock frequency before the SLEEP instruction is executed. When the clock source is switched to the INTOSC multiplexer (see Figure 3-10), the primary oscillator is shut down and the OSTS bit is cleared. The IRCF bits may be modified at any time to immediately change the system clock speed. Executing a SLEEP instruction is not required to select a new clock frequency from the INTOSC multiplexer. If the IRCF bits are all clear, the INTOSC output is not enabled and the IOFS bit will remain clear; there will be no indication of the current clock source. The INTRC source is providing the system clocks. If the IRCF bits are changed from all clear (thus, enabling the INTOSC output), the IOFS bit becomes set after the INTOSC output becomes stable. Clocks to the system continue while the INTOSC source stabilizes, in approximately 1 ms. If the IRCF bits were previously at a non-zero value before the SLEEP instruction was executed and the INTOSC source was already stable, the IOFS bit will remain set. When a wake event occurs, the system continues to be clocked from the INTOSC multiplexer while the primary clock is started. When the primary clock becomes ready, a clock switch to the primary clock occurs (see Figure 3-8). When the clock switch is complete, the IOFS bit is cleared, the OSTS bit is set and the primary clock is providing the system clock. The IDLEN and SCS bits are not affected by the wake-up. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. FIGURE 3-10: TIMING TRANSITION TO RC_RUN MODE Note: Caution should be used when modifying a single IRCF bit. If VDD is less than 3V, it is possible to select a higher clock speed than is supported by the low VDD. Improper device operation may result if the VDD/FOSC specifications are violated. Q1 Q2 Q3 OSC1 Peripheral Program Q4 INTRC Q4 Counter Clock CPU Clock PC PC + 2 12345678 Clock Transition Q1 Q2 Q3 Q4 Q1 Q2 Q3 PC + 4PIC18F1220/1320 DS39605F-page 28 © 2007 Microchip Technology Inc. 3.4.4 EXIT TO IDLE MODE An exit from a power managed Run mode to its corresponding Idle mode is executed by setting the IDLEN bit and executing a SLEEP instruction. The CPU is halted at the beginning of the instruction following the SLEEP instruction. There are no changes to any of the clock source status bits (OSTS, IOFS or T1RUN). While the CPU is halted, the peripherals continue to be clocked from the previously selected clock source. 3.4.5 EXIT TO SLEEP MODE An exit from a power managed Run mode to Sleep mode is executed by clearing the IDLEN and SCS1:SCS0 bits and executing a SLEEP instruction. The code is no different than the method used to invoke Sleep mode from the normal operating (full power) mode. The primary clock and internal oscillator block are disabled. The INTRC will continue to operate if the WDT is enabled. The Timer1 oscillator will continue to run, if enabled in the T1CON register (Register 12-1). All clock source status bits are cleared (OSTS, IOFS and T1RUN). 3.5 Wake from Power Managed Modes An exit from any of the power managed modes is triggered by an interrupt, a Reset or a WDT time-out. This section discusses the triggers that cause exits from power managed modes. The clocking subsystem actions are discussed in each of the power managed modes (see Sections 3.2 through 3.4). Device behavior during Low-Power mode exits is summarized in Table 3-3. 3.5.1 EXIT BY INTERRUPT Any of the available interrupt sources can cause the device to exit a power managed mode and resume full power operation. To enable this functionality, an interrupt source must be enabled by setting its enable bit in one of the INTCON or PIE registers. The exit sequence is initiated when the corresponding interrupt flag bit is set. On all exits from Low-Power mode by interrupt, code execution branches to the interrupt vector if the GIE/GIEH bit (INTCON<7>) is set. Otherwise, code execution continues or resumes without branching (see Section 9.0 “Interrupts”). Note: If application code is timing sensitive, it should wait for the OSTS bit to become set before continuing. Use the interval during the low-power exit sequence (before OSTS is set) to perform timing insensitive “housekeeping” tasks.© 2007 Microchip Technology Inc. DS39605F-page 29 PIC18F1220/1320 TABLE 3-3: ACTIVITY AND EXIT DELAY ON WAKE FROM SLEEP MODE OR ANY IDLE MODE (BY CLOCK SOURCES) Clock in Power Managed Mode Primary System Clock Power Managed Mode Exit Delay Clock Ready Status Bit (OSCCON) Activity during Wake-up from Power Managed Mode Exit by Interrupt Exit by Reset Primary System Clock (PRI_IDLE mode) LP, XT, HS 5-10 μs(5) OSTS CPU and peripherals clocked by primary clock and executing instructions. Not clocked or Two-Speed Start-up (if enabled)(3). HSPLL EC, RC, INTRC(1) — INTOSC(2) IOFS T1OSC or INTRC(1) LP, XT, HS OST OSTS CPU and peripherals clocked by selected power managed mode clock and executing instructions until primary clock source becomes ready. HSPLL OST + 2 ms EC, RC, INTRC(1) 5-10 μs(5) — INTOSC(2) 1 ms(4) IOFS INTOSC(2) LP, XT, HS OST OSTS HSPLL OST + 2 ms EC, RC, INTRC(1) 5-10 μs(5) — INTOSC(2) None IOFS Sleep mode LP, XT, HS OST OSTS Not clocked or Two-Speed Start-up (if enabled) until primary clock source becomes ready(3). HSPLL OST + 2 ms EC, RC, INTRC(1) 5-10 μs(5) — INTOSC(2) 1 ms(4) IOFS Note 1: In this instance, refers specifically to the INTRC clock source. 2: Includes both the INTOSC 8 MHz source and postscaler derived frequencies. 3: Two-Speed Start-up is covered in greater detail in Section 19.3 “Two-Speed Start-up”. 4: Execution continues during the INTOSC stabilization period. 5: Required delay when waking from Sleep and all Idle modes. This delay runs concurrently with any other required delays (see Section 3.3 “Idle Modes”).PIC18F1220/1320 DS39605F-page 30 © 2007 Microchip Technology Inc. 3.5.2 EXIT BY RESET Normally, the device is held in Reset by the Oscillator Start-up Timer (OST) until the primary clock (defined in Configuration Register 1H) becomes ready. At that time, the OSTS bit is set and the device begins executing code. Code execution can begin before the primary clock becomes ready. If either the Two-Speed Start-up (see Section 19.3 “Two-Speed Start-up”) or Fail-Safe Clock Monitor (see Section 19.4 “Fail-Safe Clock Monitor”) are enabled in Configuration Register 1H, the device may begin execution as soon as the Reset source has cleared. Execution is clocked by the INTOSC multiplexer driven by the internal oscillator block. Since the OSCCON register is cleared following all Resets, the INTRC clock source is selected. A higher speed clock may be selected by modifying the IRCF bits in the OSCCON register. Execution is clocked by the internal oscillator block until either the primary clock becomes ready, or a power managed mode is entered before the primary clock becomes ready; the primary clock is then shut down. 3.5.3 EXIT BY WDT TIME-OUT A WDT time-out will cause different actions, depending on which power managed mode the device is in when the time-out occurs. If the device is not executing code (all Idle modes and Sleep mode), the time-out will result in a wake from the power managed mode (see Sections 3.2 through 3.4). If the device is executing code (all Run modes), the time-out will result in a WDT Reset (see Section 19.2 “Watchdog Timer (WDT)”). The WDT timer and postscaler are cleared by executing a SLEEP or CLRWDT instruction, the loss of a currently selected clock source (if the Fail-Safe Clock Monitor is enabled) and modifying the IRCF bits in the OSCCON register if the internal oscillator block is the system clock source. 3.5.4 EXIT WITHOUT AN OSCILLATOR START-UP DELAY Certain exits from power managed modes do not invoke the OST at all. These are: • PRI_IDLE mode, where the primary clock source is not stopped; or • the primary clock source is not any of LP, XT, HS or HSPLL modes. In these cases, the primary clock source either does not require an oscillator start-up delay, since it is already running (PRI_IDLE), or normally does not require an oscillator start-up delay (RC, EC and INTIO Oscillator modes). However, a fixed delay (approximately 10 μs) following the wake event is required when leaving Sleep and Idle modes. This delay is required for the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. 3.6 INTOSC Frequency Drift The factory calibrates the internal oscillator block output (INTOSC) for 8 MHz (see Table 22-6). However, this frequency may drift as VDD or temperature changes, which can affect the controller operation in a variety of ways. It is possible to adjust the INTOSC frequency by modifying the value in the OSCTUNE register (Register 2-1). This has the side effect that the INTRC clock source frequency is also affected. However, the features that use the INTRC source often do not require an exact frequency. These features include the Fail-Safe Clock Monitor, the Watchdog Timer and the RC_RUN/ RC_IDLE modes when the INTRC clock source is selected. Being able to adjust the INTOSC requires knowing when an adjustment is required, in which direction it should be made and in some cases, how large a change is needed. Three examples follow but other techniques may be used.© 2007 Microchip Technology Inc. DS39605F-page 31 PIC18F1220/1320 3.6.1 EXAMPLE – EUSART An adjustment may be indicated when the EUSART begins to generate framing errors, or receives data with errors while in Asynchronous mode. Framing errors indicate that the system clock frequency is too high – try decrementing the value in the OSCTUNE register to reduce the system clock frequency. Errors in data may suggest that the system clock speed is too low – increment OSCTUNE. 3.6.2 EXAMPLE – TIMERS This technique compares system clock speed to some reference clock. Two timers may be used; one timer is clocked by the peripheral clock, while the other is clocked by a fixed reference source, such as the Timer1 oscillator. Both timers are cleared, but the timer clocked by the reference generates interrupts. When an interrupt occurs, the internally clocked timer is read and both timers are cleared. If the internally clocked timer value is greater than expected, then the internal oscillator block is running too fast – decrement OSCTUNE. 3.6.3 EXAMPLE – CCP IN CAPTURE MODE A CCP module can use free running Timer1 (or Timer3), clocked by the internal oscillator block and an external event with a known period (i.e., AC power frequency). The time of the first event is captured in the CCPRxH:CCPRxL registers and is recorded for use later. When the second event causes a capture, the time of the first event is subtracted from the time of the second event. Since the period of the external event is known, the time difference between events can be calculated. If the measured time is much greater than the calculated time, the internal oscillator block is running too fast – decrement OSCTUNE. If the measured time is much less than the calculated time, the internal oscillator block is running too slow – increment OSCTUNE.PIC18F1220/1320 DS39605F-page 32 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 33 PIC18F1220/1320 4.0 RESET The PIC18F1220/1320 devices differentiate between various kinds of Reset: a) Power-on Reset (POR) b) MCLR Reset during normal operation c) MCLR Reset during Sleep d) Watchdog Timer (WDT) Reset (during execution) e) Programmable Brown-out Reset (BOR) f) RESET Instruction g) Stack Full Reset h) Stack Underflow Reset Most registers are unaffected by a Reset. Their status is unknown on POR and unchanged by all other Resets. The other registers are forced to a “Reset state”, depending on the type of Reset that occurred. Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. Status bits from the RCON register (Register 4-1), RI, TO, PD, POR and BOR, are set or cleared differently in different Reset situations, as indicated in Table 4-2. These bits are used in software to determine the nature of the Reset. See Table 4-3 for a full description of the Reset states of all registers. A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 4-1. The Enhanced MCU devices have a MCLR noise filter in the MCLR Reset path. The filter will detect and ignore small pulses. The MCLR pin is not driven low by any internal Resets, including the WDT. The MCLR input provided by the MCLR pin can be disabled with the MCLRE bit in Configuration Register 3H (CONFIG3H<7>). FIGURE 4-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT S R Q External Reset MCLR VDD OSC1 WDT Time-out VDD Rise Detect OST/PWRT INTRC(1) POR Pulse OST 10-bit Ripple Counter PWRT Chip_Reset 11-bit Ripple Counter Enable OST(2) Enable PWRT Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin. 2: See Table 4-1 for time-out situations. Brown-out Reset BOR RESET Instruction Stack Pointer Stack Full/Underflow Reset Sleep ( )_IDLE 1024 Cycles 65.5 ms 32 μs MCLREPIC18F1220/1320 DS39605F-page 34 © 2007 Microchip Technology Inc. 4.1 Power-on Reset (POR) A Power-on Reset pulse is generated on-chip when VDD rise is detected. To take advantage of the POR circuitry, just tie the MCLR pin through a resistor (1k to 10 kΩ) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. A minimum rise rate for VDD is specified (parameter D004). For a slow rise time, see Figure 4-2. When the device starts normal operation (i.e., exits the Reset condition), device operating parameters (voltage, frequency, temperature, etc.) must be met to ensure operation. If these conditions are not met, the device must be held in Reset until the operating conditions are met. FIGURE 4-2: EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) 4.2 Power-up Timer (PWRT) The Power-up Timer (PWRT) of the PIC18F1220/1320 is an 11-bit counter, which uses the INTRC source as the clock input. This yields a count of 2048 x 32 μs = 65.6 ms. While the PWRT is counting, the device is held in Reset. The power-up time delay will vary from chip-to-chip due to VDD, temperature and process variation. See DC parameter 33 for details. The PWRT is enabled by clearing configuration bit, PWRTEN. 4.3 Oscillator Start-up Timer (OST) The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over (parameter 33). This ensures that the crystal oscillator or resonator has started and stabilized. The OST time-out is invoked only for XT, LP, HS and HSPLL modes and only on Power-on Reset, or on exit from most low-power modes. 4.4 PLL Lock Time-out With the PLL enabled in its PLL mode, the time-out sequence following a Power-on Reset is slightly different from other oscillator modes. A portion of the Power-up Timer is used to provide a fixed time-out that is sufficient for the PLL to lock to the main oscillator frequency. This PLL lock time-out (TPLL) is typically 2 ms and follows the Oscillator Start-up Time-out. 4.5 Brown-out Reset (BOR) A configuration bit, BOR, can disable (if clear/ programmed), or enable (if set) the Brown-out Reset circuitry. If VDD falls below VBOR (parameter D005) for greater than TBOR (parameter 35), the brown-out situation will reset the chip. A Reset may not occur if VDD falls below VBOR for less than TBOR. The chip will remain in Brown-out Reset until VDD rises above VBOR. If the Power-up Timer is enabled, it will be invoked after VDD rises above VBOR; it then will keep the chip in Reset for an additional time delay, TPWRT (parameter 33). If VDD drops below VBOR while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above VBOR, the Power-up Timer will execute the additional time delay. Enabling BOR Reset does not automatically enable the PWRT. 4.6 Time-out Sequence On power-up, the time-out sequence is as follows: First, after the POR pulse has cleared, PWRT time-out is invoked (if enabled). Then, the OST is activated. The total time-out will vary based on oscillator configuration and the status of the PWRT. For example, in RC mode with the PWRT disabled, there will be no time-out at all. Figure 4-3, Figure 4-4, Figure 4-5, Figure 4-6 and Figure 4-7 depict time-out sequences on power-up. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, all time-outs will expire. Bringing MCLR high will begin execution immediately (Figure 4-5). This is useful for testing purposes or to synchronize more than one PIC18FXXXX device operating in parallel. Table 4-2 shows the Reset conditions for some Special Function Registers, while Table 4-3 shows the Reset conditions for all the registers. Note 1: External Power-on Reset circuit is required only if the VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 kΩ is recommended to make sure that the voltage drop across R does not violate the device’s electrical specification. 3: R1 ≥ 1 kΩ will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). C R1 D R VDD MCLR PIC18FXXXX VDD© 2007 Microchip Technology Inc. DS39605F-page 35 PIC18F1220/1320 TABLE 4-1: TIME-OUT IN VARIOUS SITUATIONS REGISTER 4-1: RCON REGISTER BITS AND POSITIONS TABLE 4-2: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER Oscillator Configuration Power-up(2) and Brown-out Exit from Low-Power Mode PWRTEN = 0 PWRTEN = 1 HSPLL 66 ms(1) + 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2) HS, XT, LP 66 ms(1) + 1024 TOSC 1024 TOSC 1024 TOSC EC, ECIO 66 ms(1) 5-10 μs(3) 5-10 μs(3) RC, RCIO 66 ms(1) 5-10 μs(3) 5-10 μs(3) INTIO1, INTIO2 66 ms(1) 5-10 μs(3) 5-10 μs(3) Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay. 2: 2 ms is the nominal time required for the 4x PLL to lock. 3: The program memory bias start-up time is always invoked on POR, wake-up from Sleep, or on any exit from power managed mode that disables the CPU and instruction execution. R/W-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 IPEN — — RI TO PD POR BOR bit 7 bit 0 Note: Refer to Section 5.14 “RCON Register” for bit definitions. Condition Program Counter RCON Register RI TO PD POR BOR STKFUL STKUNF Power-on Reset 0000h 0--1 1100 1 1 1 0 0 0 0 RESET Instruction 0000h 0--0 uuuu 0 u u u u u u Brown-out 0000h 0--1 11u- 1 1 1 u 0 u u MCLR during Power Managed Run modes 0000h 0--u 1uuu u 1 u u u u u MCLR during Power Managed Idle modes and Sleep 0000h 0--u 10uu u 1 0 u u u u WDT Time-out during Full Power or Power Managed Run 0000h 0--u 0uuu u 0 u u u u u MCLR during Full Power Execution 0000h 0--u uuuu u u u u u u u Stack Full Reset (STVR = 1) 1 u Stack Underflow Reset (STVR = 1) u 1 Stack Underflow Error (not an actual Reset, STVR = 0) 0000h u--u uuuu u u u u u u 1 WDT Time-out during Power Managed Idle or Sleep PC + 2 u--u 00uu u 0 0 u u u u Interrupt Exit from Power Managed modes PC + 2 u--u u0uu u u 0 u u u u Legend: u = unchanged, x = unknown, – = unimplemented bit, read as ‘0’ Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the interrupt vector (0x000008h or 0x000018h).PIC18F1220/1320 DS39605F-page 36 © 2007 Microchip Technology Inc. TABLE 4-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt TOSU 1220 1320 ---0 0000 ---0 0000 ---0 uuuu(3) TOSH 1220 1320 0000 0000 0000 0000 uuuu uuuu(3) TOSL 1220 1320 0000 0000 0000 0000 uuuu uuuu(3) STKPTR 1220 1320 00-0 0000 00-0 0000 uu-u uuuu(3) PCLATU 1220 1320 ---0 0000 ---0 0000 ---u uuuu PCLATH 1220 1320 0000 0000 0000 0000 uuuu uuuu PCL 1220 1320 0000 0000 0000 0000 PC + 2(2) TBLPTRU 1220 1320 --00 0000 --00 0000 --uu uuuu TBLPTRH 1220 1320 0000 0000 0000 0000 uuuu uuuu TBLPTRL 1220 1320 0000 0000 0000 0000 uuuu uuuu TABLAT 1220 1320 0000 0000 0000 0000 uuuu uuuu PRODH 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu PRODL 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu INTCON 1220 1320 0000 000x 0000 000u uuuu uuuu(1) INTCON2 1220 1320 1111 -1-1 1111 -1-1 uuuu -u-u(1) INTCON3 1220 1320 11-0 0-00 11-0 0-00 uu-u u-uu(1) INDF0 1220 1320 N/A N/A N/A POSTINC0 1220 1320 N/A N/A N/A POSTDEC0 1220 1320 N/A N/A N/A PREINC0 1220 1320 N/A N/A N/A PLUSW0 1220 1320 N/A N/A N/A FSR0H 1220 1320 ---- 0000 ---- 0000 ---- uuuu FSR0L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu WREG 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu INDF1 1220 1320 N/A N/A N/A POSTINC1 1220 1320 N/A N/A N/A POSTDEC1 1220 1320 N/A N/A N/A PREINC1 1220 1320 N/A N/A N/A PLUSW1 1220 1320 N/A N/A N/A FSR1H 1220 1320 ---- 0000 ---- 0000 ---- uuuu FSR1L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-2 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the Oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: Bit 5 of PORTA is enabled if MCLR is disabled.© 2007 Microchip Technology Inc. DS39605F-page 37 PIC18F1220/1320 BSR 1220 1320 ---- 0000 ---- 0000 ---- uuuu INDF2 1220 1320 N/A N/A N/A POSTINC2 1220 1320 N/A N/A N/A POSTDEC2 1220 1320 N/A N/A N/A PREINC2 1220 1320 N/A N/A N/A PLUSW2 1220 1320 N/A N/A N/A FSR2H 1220 1320 ---- 0000 ---- 0000 ---- uuuu FSR2L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu STATUS 1220 1320 ---x xxxx ---u uuuu ---u uuuu TMR0H 1220 1320 0000 0000 0000 0000 uuuu uuuu TMR0L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu T0CON 1220 1320 1111 1111 1111 1111 uuuu uuuu OSCCON 1220 1320 0000 q000 0000 q000 uuuu qquu LVDCON 1220 1320 --00 0101 --00 0101 --uu uuuu WDTCON 1220 1320 ---- ---0 ---- ---0 ---- ---u RCON(4) 1220 1320 0--1 11q0 0--q qquu u--u qquu TMR1H 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu TMR1L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu T1CON 1220 1320 0000 0000 u0uu uuuu uuuu uuuu TMR2 1220 1320 0000 0000 0000 0000 uuuu uuuu PR2 1220 1320 1111 1111 1111 1111 1111 1111 T2CON 1220 1320 -000 0000 -000 0000 -uuu uuuu ADRESH 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu ADRESL 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu ADCON0 1220 1320 00-0 0000 00-0 0000 uu-u uuuu ADCON1 1220 1320 -000 0000 -000 0000 -uuu uuuu ADCON2 1220 1320 0-00 0000 0-00 0000 u-uu uuuu CCPR1H 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu CCPR1L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu CCP1CON 1220 1320 0000 0000 0000 0000 uuuu uuuu PWM1CON 1220 1320 0000 0000 0000 0000 uuuu uuuu ECCPAS 1220 1320 0000 0000 0000 0000 uuuu uuuu TABLE 4-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-2 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the Oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: Bit 5 of PORTA is enabled if MCLR is disabled.PIC18F1220/1320 DS39605F-page 38 © 2007 Microchip Technology Inc. TMR3H 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu TMR3L 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu T3CON 1220 1320 0-00 0000 u-uu uuuu u-uu uuuu SPBRGH 1220 1320 0000 0000 0000 0000 uuuu uuuu SPBRG 1220 1320 0000 0000 0000 0000 uuuu uuuu RCREG 1220 1320 0000 0000 0000 0000 uuuu uuuu TXREG 1220 1320 0000 0000 0000 0000 uuuu uuuu TXSTA 1220 1320 0000 0010 0000 0010 uuuu uuuu RCSTA 1220 1320 0000 000x 0000 000x uuuu uuuu BAUDCTL 1220 1320 -1-1 0-00 -1-1 0-00 -u-u u-uu EEADR 1220 1320 0000 0000 0000 0000 uuuu uuuu EEDATA 1220 1320 0000 0000 0000 0000 uuuu uuuu EECON2 1220 1320 0000 0000 0000 0000 0000 0000 EECON1 1220 1320 xx-0 x000 uu-0 u000 uu-0 u000 IPR2 1220 1320 1--1 -11- 1--1 -11- u--u -uuPIR2 1220 1320 0--0 -00- 0--0 -00- u--u -uu-(1) PIE2 1220 1320 0--0 -00- 0--0 -00- u--u -uuIPR1 1220 1320 -111 -111 -111 -111 -uuu -uuu PIR1 1220 1320 -000 -000 -000 -000 -uuu -uuu(1) PIE1 1220 1320 -000 -000 -000 -000 -uuu -uuu OSCTUNE 1220 1320 --00 0000 --00 0000 --uu uuuu TRISB 1220 1320 1111 1111 1111 1111 uuuu uuuu TRISA(5) 1220 1320 11-1 1111(5) 11-1 1111(5) uu-u uuuu(5) LATB 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu LATA(5) 1220 1320 xx-x xxxx(5) uu-u uuuu(5) uu-u uuuu(5) PORTB 1220 1320 xxxx xxxx uuuu uuuu uuuu uuuu PORTA(5,6) 1220 1320 xx0x 0000(5,6) uu0u 0000(5,6) uuuu uuuu(5,6) TABLE 4-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-2 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the Oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: Bit 5 of PORTA is enabled if MCLR is disabled.© 2007 Microchip Technology Inc. DS39605F-page 39 PIC18F1220/1320 FIGURE 4-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT) FIGURE 4-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 FIGURE 4-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TPWRT TOSTPIC18F1220/1320 DS39605F-page 40 © 2007 Microchip Technology Inc. FIGURE 4-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT) FIGURE 4-7: TIME-OUT SEQUENCE ON POR W/PLL ENABLED (MCLR TIED TO VDD) VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET 0V 1V 5V TPWRT TOST TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET PLL TIME-OUT TPLL Note: TOST = 1024 clock cycles. TPLL ≈ 2 ms max. First three stages of the PWRT timer.© 2007 Microchip Technology Inc. DS39605F-page 41 PIC18F1220/1320 5.0 MEMORY ORGANIZATION There are three memory types in Enhanced MCU devices. These memory types are: • Program Memory • Data RAM • Data EEPROM Data and program memory use separate busses, which allows for concurrent access of these types. Additional detailed information for Flash program memory and data EEPROM is provided in Section 6.0 “Flash Program Memory” and Section 7.0 “Data EEPROM Memory”, respectively. FIGURE 5-1: PROGRAM MEMORY MAP AND STACK FOR PIC18F1220 5.1 Program Memory Organization A 21-bit program counter is capable of addressing the 2-Mbyte program memory space. Accessing a location between the physically implemented memory and the 2-Mbyte address will cause a read of all ‘0’s (a NOP instruction). The PIC18F1220 has 4 Kbytes of Flash memory and can store up to 2,048 single-word instructions. The PIC18F1320 has 8 Kbytes of Flash memory and can store up to 4,096 single-word instructions. The Reset vector address is at 0000h and the interrupt vector addresses are at 0008h and 0018h. The program memory maps for the PIC18F1220 and PIC18F1320 devices are shown in Figure 5-1 and Figure 5-2, respectively. FIGURE 5-2: PROGRAM MEMORY MAP AND STACK FOR PIC18F1320 PC<20:0> Stack Level 1 • Stack Level 31 Reset Vector Low Priority Interrupt Vector • • CALL,RCALL,RETURN RETFIE,RETLW 21 0000h 0018h On-Chip Program Memory High Priority Interrupt Vector 0008h User Memory Space 1FFFFFh 1000h 0FFFh Read ‘0’ 200000h PC<20:0> Stack Level 1 • Stack Level 31 Reset Vector Low Priority Interrupt Vector • • CALL,RCALL,RETURN RETFIE,RETLW 21 0000h 0018h 2000h 1FFFh On-Chip Program Memory High Priority Interrupt Vector 0008h User Memory Space Read ‘0’ 1FFFFFh 200000hPIC18F1220/1320 DS39605F-page 42 © 2007 Microchip Technology Inc. 5.2 Return Address Stack The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC (Program Counter) is pushed onto the stack when a CALL or RCALL instruction is executed, or an interrupt is Acknowledged. The PC value is pulled off the stack on a RETURN, RETLW or a RETFIE instruction. PCLATU and PCLATH are not affected by any of the RETURN or CALL instructions. The stack operates as a 31-word by 21-bit RAM and a 5-bit stack pointer, with the Stack Pointer initialized to 00000B after all Resets. There is no RAM associated with Stack Pointer, 00000B. This is only a Reset value. During a CALL type instruction, causing a push onto the stack, the Stack Pointer is first incremented and the RAM location pointed to by the Stack Pointer (STKPTR) register is written with the contents of the PC (already pointing to the instruction following the CALL). During a RETURN type instruction, causing a pop from the stack, the contents of the RAM location pointed to by the STKPTR are transferred to the PC and then the Stack Pointer is decremented. The stack space is not part of either program or data space. The Stack Pointer is readable and writable and the address on the top of the stack is readable and writable through the top-of-stack Special File Registers. Data can also be pushed to or popped from the stack using the top-of-stack SFRs. Status bits indicate if the stack is full, has overflowed or underflowed. 5.2.1 TOP-OF-STACK ACCESS The top of the stack is readable and writable. Three register locations, TOSU, TOSH and TOSL, hold the contents of the stack location pointed to by the STKPTR register (Figure 5-3). This allows users to implement a software stack if necessary. After a CALL, RCALL or interrupt, the software can read the pushed value by reading the TOSU, TOSH and TOSL registers. These values can be placed on a user defined software stack. At return time, the software can replace the TOSU, TOSH and TOSL and do a return. The user must disable the global interrupt enable bits while accessing the stack to prevent inadvertent stack corruption. 5.2.2 RETURN STACK POINTER (STKPTR) The STKPTR register (Register 5-1) contains the stack pointer value, the STKFUL (Stack Full) status bit and the STKUNF (Stack Underflow) status bits. The value of the Stack Pointer can be 0 through 31. The Stack Pointer increments before values are pushed onto the stack and decrements after values are popped off the stack. At Reset, the Stack Pointer value will be zero. The user may read and write the Stack Pointer value. This feature can be used by a Real-Time Operating System for return stack maintenance. After the PC is pushed onto the stack 31 times (without popping any values off the stack), the STKFUL bit is set. The STKFUL bit is cleared by software or by a POR. The action that takes place when the stack becomes full depends on the state of the STVR (Stack Overflow Reset Enable) configuration bit. (Refer to Section 19.1 “Configuration Bits” for a description of the device configuration bits.) If STVR is set (default), the 31st push will push the (PC + 2) value onto the stack, set the STKFUL bit and reset the device. The STKFUL bit will remain set and the Stack Pointer will be set to zero. If STVR is cleared, the STKFUL bit will be set on the 31st push and the Stack Pointer will increment to 31. Any additional pushes will not overwrite the 31st push and STKPTR will remain at 31. When the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the PC and sets the STKUNF bit, while the Stack Pointer remains at zero. The STKUNF bit will remain set until cleared by software or a POR occurs. FIGURE 5-3: RETURN ADDRESS STACK AND ASSOCIATED REGISTERS Note: Returning a value of zero to the PC on an underflow has the effect of vectoring the program to the Reset vector, where the stack conditions can be verified and appropriate actions can be taken. This is not the same as a Reset, as the contents of the SFRs are not affected. 00011 001A34h 11111 11110 11101 00010 00001 00000 00010 Return Address Stack Top-of-Stack 000D58h TOSU TOSH TOSL 00h 1Ah 34h STKPTR<4:0>© 2007 Microchip Technology Inc. DS39605F-page 43 PIC18F1220/1320 REGISTER 5-1: STKPTR REGISTER 5.2.3 PUSH AND POP INSTRUCTIONS Since the Top-of-Stack (TOS) is readable and writable, the ability to push values onto the stack and pull values off the stack, without disturbing normal program execution, is a desirable option. To push the current PC value onto the stack, a PUSH instruction can be executed. This will increment the Stack Pointer and load the current PC value onto the stack. TOSU, TOSH and TOSL can then be modified to place data or a return address on the stack. The ability to pull the TOS value off of the stack and replace it with the value that was previously pushed onto the stack, without disturbing normal execution, is achieved by using the POP instruction. The POP instruction discards the current TOS by decrementing the Stack Pointer. The previous value pushed onto the stack then becomes the TOS value. 5.2.4 STACK FULL/UNDERFLOW RESETS These Resets are enabled by programming the STVR bit in Configuration Register 4L. When the STVR bit is cleared, a full or underflow condition will set the appropriate STKFUL or STKUNF bit, but not cause a device Reset. When the STVR bit is set, a full or underflow condition will set the appropriate STKFUL or STKUNF bit and then cause a device Reset. The STKFUL or STKUNF bits are cleared by the user software or a Power-on Reset. R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 STKFUL STKUNF — SP4 SP3 SP2 SP1 SP0 bit 7 bit 0 bit 7(1) STKFUL: Stack Full Flag bit 1 = Stack became full or overflowed 0 = Stack has not become full or overflowed bit 6(1) STKUNF: Stack Underflow Flag bit 1 = Stack underflow occurred 0 = Stack underflow did not occur bit 5 Unimplemented: Read as ‘0’ bit 4-0 SP4:SP0: Stack Pointer Location bits Note 1: Bit 7 and bit 6 are cleared by user software or by a POR. Legend: R = Readable bit W = Writable bit U = Unimplemented C = Clearable only bit -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 44 © 2007 Microchip Technology Inc. 5.3 Fast Register Stack A “fast return” option is available for interrupts. A fast register stack is provided for the Status, WREG and BSR registers and is only one in depth. The stack is not readable or writable and is loaded with the current value of the corresponding register when the processor vectors for an interrupt. The values in the registers are then loaded back into the working registers, if the RETFIE, FAST instruction is used to return from the interrupt. All interrupt sources will push values into the stack registers. If both low and high priority interrupts are enabled, the stack registers cannot be used reliably to return from low priority interrupts. If a high priority interrupt occurs while servicing a low priority interrupt, the stack register values stored by the low priority interrupt will be overwritten. Users must save the key registers in software during a low priority interrupt. If interrupt priority is not used, all interrupts may use the fast register stack for returns from interrupt. If no interrupts are used, the fast register stack can be used to restore the Status, WREG and BSR registers at the end of a subroutine call. To use the fast register stack for a subroutine call, a CALL LABEL, FAST instruction must be executed to save the Status, WREG and BSR registers to the fast register stack. A RETURN, FAST instruction is then executed to restore these registers from the fast register stack. Example 5-1 shows a source code example that uses the fast register stack during a subroutine call and return. EXAMPLE 5-1: FAST REGISTER STACK CODE EXAMPLE 5.4 PCL, PCLATH and PCLATU The Program Counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21-bits wide. The low byte, known as the PCL register, is both readable and writable. The high byte, or PCH register, contains the PC<15:8> bits and is not directly readable or writable. Updates to the PCH register may be performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits and is not directly readable or writable. Updates to the PCU register may be performed through the PCLATU register. The contents of PCLATH and PCLATU will be transferred to the program counter by any operation that writes PCL. Similarly, the upper two bytes of the program counter will be transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 5.8.1 “Computed GOTO”). The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the LSB of PCL is fixed to a value of ‘0’. The PC increments by 2 to address sequential instructions in the program memory. The CALL, RCALL, GOTO and program branch instructions write to the program counter directly. For these instructions, the contents of PCLATH and PCLATU are not transferred to the program counter. CALL SUB1, FAST ;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK • • SUB1 • • RETURN, FAST ;RESTORE VALUES SAVED ;IN FAST REGISTER STACK© 2007 Microchip Technology Inc. DS39605F-page 45 PIC18F1220/1320 5.5 Clocking Scheme/Instruction Cycle The clock input (from OSC1) is internally divided by four to generate four non-overlapping quadrature clocks, namely Q1, Q2, Q3 and Q4. Internally, the Program Counter (PC) is incremented every Q1, the instruction is fetched from the program memory and latched into the instruction register in Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 5-4. 5.6 Instruction Flow/Pipelining An “Instruction Cycle” consists of four Q cycles (Q1, Q2, Q3 and Q4). The instruction fetch and execute are pipelined such that fetch takes one instruction cycle, while decode and execute takes another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g., GOTO), then two cycles are required to complete the instruction (Example 5-2). A fetch cycle begins with the Program Counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the “Instruction Register” (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3 and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write). FIGURE 5-4: CLOCK/INSTRUCTION CYCLE EXAMPLE 5-2: INSTRUCTION PIPELINE FLOW Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Q3 Q4 PC OSC2/CLKO (RC Mode) PC PC + 2 PC + 4 Fetch INST (PC) Execute INST (PC – 2) Fetch INST (PC + 2) Execute INST (PC) Fetch INST (PC + 4) Execute INST (PC + 2) Internal Phase Clock All instructions are single cycle, except for any program branches. These take two cycles, since the fetch instruction is “flushed” from the pipeline, while the new instruction is being fetched and then executed. TCY0 TCY1 TCY2 TCY3 TCY4 TCY5 1. MOVLW 55h Fetch 1 Execute 1 2. MOVWF PORTB Fetch 2 Execute 2 3. BRA SUB_1 Fetch 3 Execute 3 4. BSF PORTA, BIT3 (Forced NOP) Fetch 4 Flush (NOP) 5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1PIC18F1220/1320 DS39605F-page 46 © 2007 Microchip Technology Inc. 5.7 Instructions in Program Memory The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program memory. The Least Significant Byte of an instruction word is always stored in a program memory location with an even address (LSB = 0). Figure 5-5 shows an example of how instruction words are stored in the program memory. To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSB will always read ‘0’ (see Section 5.4 “PCL, PCLATH and PCLATU”). The CALL and GOTO instructions have the absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, the data contained in the instruction is a word address. The word address is written to PC<20:1>, which accesses the desired byte address in program memory. Instruction #2 in Figure 5-5 shows how the instruction ‘GOTO 000006h’ is encoded in the program memory. Program branch instructions, which encode a relative address offset, operate in the same manner. The offset value stored in a branch instruction represents the number of single-word instructions that the PC will be offset by. Section 20.0 “Instruction Set Summary” provides further details of the instruction set. FIGURE 5-5: INSTRUCTIONS IN PROGRAM MEMORY 5.7.1 TWO-WORD INSTRUCTIONS PIC18F1220/1320 devices have four two-word instructions: MOVFF, CALL, GOTO and LFSR. The second word of these instructions has the 4 MSBs set to ‘1’s and is decoded as a NOP instruction. The lower 12 bits of the second word contain data to be used by the instruction. If the first word of the instruction is executed, the data in the second word is accessed. If the second word of the instruction is executed by itself (first word was skipped), it will execute as a NOP. This action is necessary when the two-word instruction is preceded by a conditional instruction that results in a skip operation. A program example that demonstrates this concept is shown in Example 5-3. Refer to Section 20.0 “Instruction Set Summary” for further details of the instruction set. EXAMPLE 5-3: TWO-WORD INSTRUCTIONS Word Address LSB = 1 LSB = 0 ↓ Program Memory Byte Locations → 000000h 000002h 000004h 000006h Instruction 1: MOVLW 055h 0Fh 55h 000008h Instruction 2: GOTO 000006h EFh 03h 00000Ah F0h 00h 00000Ch Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh F4h 56h 000010h 000012h 000014h CASE 1: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; No, skip this word 1111 0100 0101 0110 ; Execute this word as a NOP 0010 0100 0000 0000 ADDWF REG3 ; continue code CASE 2: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes, execute this word 1111 0100 0101 0110 ; 2nd word of instruction 0010 0100 0000 0000 ADDWF REG3 ; continue code© 2007 Microchip Technology Inc. DS39605F-page 47 PIC18F1220/1320 5.8 Look-up Tables Look-up tables are implemented two ways: • Computed GOTO • Table Reads 5.8.1 COMPUTED GOTO A computed GOTO is accomplished by adding an offset to the program counter (see Example 5-4). A look-up table can be formed with an ADDWF PCL instruction and a group of RETLW 0xnn instructions. WREG is loaded with an offset into the table before executing a call to that table. The first instruction of the called routine is the ADDWF PCL instruction. The next instruction executed will be one of the RETLW 0xnn instructions, that returns the value 0xnn to the calling function. The offset value (in WREG) specifies the number of bytes that the program counter should advance and should be multiples of 2 (LSB = 0). In this method, only one data byte may be stored in each instruction location and room on the return address stack is required. EXAMPLE 5-4: COMPUTED GOTO USING AN OFFSET VALUE 5.8.2 TABLE READS/TABLE WRITES A better method of storing data in program memory allows two bytes of data to be stored in each instruction location. Look-up table data may be stored two bytes per program word by using table reads and writes. The Table Pointer (TBLPTR) register specifies the byte address and the Table Latch (TABLAT) register contains the data that is read from or written to program memory. Data is transferred to/from program memory, one byte at a time. The table read/table write operation is discussed further in Section 6.1 “Table Reads and Table Writes”. 5.9 Data Memory Organization The data memory is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. Figure 5-6 shows the data memory organization for the PIC18F1220/1320 devices. The data memory map is divided into as many as 16 banks that contain 256 bytes each. The lower 4 bits of the Bank Select Register (BSR<3:0>) select which bank will be accessed. The upper 4 bits for the BSR are not implemented. The data memory contains Special Function Registers (SFR) and General Purpose Registers (GPR). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratch pad operations in the user’s application. The SFRs start at the last location of Bank 15 (FFFh) and extend towards F80h. Any remaining space beyond the SFRs in the Bank may be implemented as GPRs. GPRs start at the first location of Bank 0 and grow upwards. Any read of an unimplemented location will read as ‘0’s. The entire data memory may be accessed directly or indirectly. Direct addressing may require the use of the BSR register. Indirect addressing requires the use of a File Select Register (FSRn) and a corresponding Indirect File Operand (INDFn). Each FSR holds a 12-bit address value that can be used to access any location in the Data Memory map without banking. See Section 5.12 “Indirect Addressing, INDF and FSR Registers” for indirect addressing details. The instruction set and architecture allow operations across all banks. This may be accomplished by indirect addressing or by the use of the MOVFF instruction. The MOVFF instruction is a two-word/two-cycle instruction that moves a value from one register to another. To ensure that commonly used registers (SFRs and select GPRs) can be accessed in a single cycle, regardless of the current BSR values, an Access Bank is implemented. A segment of Bank 0 and a segment of Bank 15 comprise the Access RAM. Section 5.10 “Access Bank” provides a detailed description of the Access RAM. 5.9.1 GENERAL PURPOSE REGISTER FILE Enhanced MCU devices may have banked memory in the GPR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other Resets. Data RAM is available for use as GPR registers by all instructions. The second half of Bank 15 (F80h to FFFh) contains SFRs. All other banks of data memory contain GPRs, starting with Bank 0. MOVFW OFFSET CALL TABLE ORG 0xnn00 TABLE ADDWF PCL RETLW 0xnn RETLW 0xnn RETLW 0xnn . . .PIC18F1220/1320 DS39605F-page 48 © 2007 Microchip Technology Inc. FIGURE 5-6: DATA MEMORY MAP FOR PIC18F1220/1320 DEVICES Bank 0 Bank 14 Bank 15 BSR<3:0> Data Memory Map = 0000 = 1111 080h 07Fh F80h FFFh 00h 7Fh 80h FFh Access Bank When a = 0, The BSR is ignored and the Access Bank is used. The first 128 bytes are General Purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15). When a = 1, The BSR specifies the Bank used by the instruction. F7Fh F00h EFFh 0FFh 000h Access RAM FFh 00h FFh 00h GPR SFR Unused Access RAM High Access RAM Low Bank 1 to Unused = 1110 Read ‘00h’ = 0001 (SFRs)© 2007 Microchip Technology Inc. DS39605F-page 49 PIC18F1220/1320 5.9.2 SPECIAL FUNCTION REGISTERS The Special Function Registers (SFRs) are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. A list of these registers is given in Table 5-1 and Table 5-2. The SFRs can be classified into two sets: those associated with the “core” function and those related to the peripheral functions. Those registers related to the “core” are described in this section, while those related to the operation of the peripheral features are described in the section of that peripheral feature. The SFRs are typically distributed among the peripherals whose functions they control. The unused SFR locations will be unimplemented and read as ‘0’s. TABLE 5-1: SPECIAL FUNCTION REGISTER MAP FOR PIC18F1220/1320 DEVICES Address Name Address Name Address Name Address Name FFFh TOSU FDFh INDF2(2) FBFh CCPR1H F9Fh IPR1 FFEh TOSH FDEh POSTINC2(2) FBEh CCPR1L F9Eh PIR1 FFDh TOSL FDDh POSTDEC2(2) FBDh CCP1CON F9Dh PIE1 FFCh STKPTR FDCh PREINC2(2) FBCh — F9Ch — FFBh PCLATU FDBh PLUSW2(2) FBBh — F9Bh OSCTUNE FFAh PCLATH FDAh FSR2H FBAh — F9Ah — FF9h PCL FD9h FSR2L FB9h — F99h — FF8h TBLPTRU FD8h STATUS FB8h — F98h — FF7h TBLPTRH FD7h TMR0H FB7h PWM1CON F97h — FF6h TBLPTRL FD6h TMR0L FB6h ECCPAS F96h — FF5h TABLAT FD5h T0CON FB5h — F95h — FF4h PRODH FD4h — FB4h — F94h — FF3h PRODL FD3h OSCCON FB3h TMR3H F93h TRISB FF2h INTCON FD2h LVDCON FB2h TMR3L F92h TRISA FF1h INTCON2 FD1h WDTCON FB1h T3CON F91h — FF0h INTCON3 FD0h RCON FB0h SPBRGH F90h — FEFh INDF0(2) FCFh TMR1H FAFh SPBRG F8Fh — FEEh POSTINC0(2) FCEh TMR1L FAEh RCREG F8Eh — FEDh POSTDEC0(2) FCDh T1CON FADh TXREG F8Dh — FECh PREINC0(2) FCCh TMR2 FACh TXSTA F8Ch — FEBh PLUSW0(2) FCBh PR2 FABh RCSTA F8Bh — FEAh FSR0H FCAh T2CON FAAh BAUDCTL F8Ah LATB FE9h FSR0L FC9h — FA9h EEADR F89h LATA FE8h WREG FC8h — FA8h EEDATA F88h — FE7h INDF1(2) FC7h — FA7h EECON2 F87h — FE6h POSTINC1(2) FC6h — FA6h EECON1 F86h — FE5h POSTDEC1(2) FC5h — FA5h — F85h — FE4h PREINC1(2) FC4h ADRESH FA4h — F84h — FE3h PLUSW1(2) FC3h ADRESL FA3h — F83h — FE2h FSR1H FC2h ADCON0 FA2h IPR2 F82h — FE1h FSR1L FC1h ADCON1 FA1h PIR2 F81h PORTB FE0h BSR FC0h ADCON2 FA0h PIE2 F80h PORTA Note 1: Unimplemented registers are read as ‘0’. 2: This is not a physical register.PIC18F1220/1320 DS39605F-page 50 © 2007 Microchip Technology Inc. TABLE 5-2: REGISTER FILE SUMMARY (PIC18F1220/1320) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: TOSU — — — Top-of-Stack Upper Byte (TOS<20:16>) ---0 0000 36, 42 TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 36, 42 TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 36, 42 STKPTR STKFUL STKUNF — Return Stack Pointer 00-0 0000 36, 43 PCLATU — — bit 21(3) Holding Register for PC<20:16> ---0 0000 36, 44 PCLATH Holding Register for PC<15:8> 0000 0000 36, 44 PCL PC Low Byte (PC<7:0>) 0000 0000 36, 44 TBLPTRU — — bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 36, 60 TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 36, 60 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 36, 60 TABLAT Program Memory Table Latch 0000 0000 36, 60 PRODH Product Register High Byte xxxx xxxx 36, 71 PRODL Product Register Low Byte xxxx xxxx 36, 71 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 36, 75 INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP 1111 -1-1 36, 76 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 36, 77 INDF0 Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register) N/A 36, 53 POSTINC0 Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register) N/A 36, 53 POSTDEC0 Uses contents of FSR0 to address data memory– value of FSR0 post-decremented (not a physical register) N/A 36, 53 PREINC0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) N/A 36, 53 PLUSW0 Uses contents of FSR0 to address data memory – value of FSR0 offset by W (not a physical register) N/A 36, 53 FSR0H — — — — Indirect Data Memory Address Pointer 0 High ---- 0000 36, 53 FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 36, 53 WREG Working Register xxxx xxxx 36 INDF1 Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register) N/A 36, 53 POSTINC1 Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register) N/A 36, 53 POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register) N/A 36, 53 PREINC1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) N/A 36, 53 PLUSW1 Uses contents of FSR1 to address data memory – value of FSR1 offset by W (not a physical register) N/A 36, 53 FSR1H — — — — Indirect Data Memory Address Pointer 1 High ---- 0000 36, 53 FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 36, 53 BSR — — — — Bank Select Register ---- 0000 37, 52 INDF2 Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register) N/A 37, 53 POSTINC2 Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register) N/A 37, 53 POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register) N/A 37, 53 PREINC2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) N/A 37, 53 PLUSW2 Uses contents of FSR2 to address data memory – value of FSR2 offset by W (not a physical register) N/A 37, 53 FSR2H — — — — Indirect Data Memory Address Pointer 2 High ---- 0000 37, 53 FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 37, 53 STATUS — — — N OV Z DC C ---x xxxx 37, 55 TMR0H Timer0 Register High Byte 0000 0000 37, 101 TMR0L Timer0 Register Low Byte xxxx xxxx 37, 101 T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 37, 99 OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 0000 q000 37, 17 LVDCON — — IVRST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 --00 0101 37, 167 WDTCON — — — — — — — SWDTEN --- ---0 37, 180 RCON IPEN — — RI TO PD POR BOR 0--1 11q0 35, 56, 84 Legend: x = unknown, u = unchanged, – = unimplemented, q = value depends on condition Note 1: RA6 and associated bits are configured as port pins in RCIO, ECIO and INTIO2 (with port function on RA6) Oscillator mode only and read ‘0’ in all other oscillator modes. 2: RA7 and associated bits are configured as port pins in INTIO2 Oscillator mode only and read ‘0’ in all other modes. 3: Bit 21 of the PC is only available in Test mode and Serial Programming modes. 4: The RA5 port bit is only available when MCLRE fuse (CONFIG3H<7>) is programmed to ‘0’. Otherwise, RA5 reads ‘0’. This bit is read-only.© 2007 Microchip Technology Inc. DS39605F-page 51 PIC18F1220/1320 TMR1H Timer1 Register High Byte xxxx xxxx 37, 108 TMR1L Timer1 Register Low Byte xxxx xxxx 37, 108 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 37, 103 TMR2 Timer2 Register 0000 0000 37, 109 PR2 Timer2 Period Register 1111 1111 37, 109 T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 37, 109 ADRESH A/D Result Register High Byte xxxx xxxx 37, 164 ADRESL A/D Result Register Low Byte xxxx xxxx 37, 164 ADCON0 VCFG1 VCFG0 — CHS2 CHS1 CHS0 GO/DONE ADON 00-0 0000 37, 155 ADCON1 — PCFG6 PCFG5 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 -000 0000 37, 156 ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0-00 0000 37, 157 CCPR1H Capture/Compare/PWM Register 1 High Byte xxxx xxxx 37. 116 CCPR1L Capture/Compare/PWM Register 1 Low Byte xxxx xxxx 37, 116 CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 37, 115 PWM1CON PRSEN PDC6 PDC5 PDC4 PDC3 PDC2 PDC1 PDC0 0000 0000 37, 126 ECCPAS ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 0000 0000 37, 127 TMR3H Timer3 Register High Byte xxxx xxxx 38, 113 TMR3L Timer3 Register Low Byte xxxx xxxx 38, 113 T3CON RD16 — T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0-00 0000 38, 111 SPBRGH EUSART Baud Rate Generator High Byte 0000 0000 38 SPBRG EUSART Baud Rate Generator Low Byte 0000 0000 38, 135 RCREG EUSART Receive Register 0000 0000 38, 143, 142 TXREG EUSART Transmit Register 0000 0000 38, 140, 142 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 38, 132 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 38, 133 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 38 EEADR EEPROM Address Register 0000 0000 38, 67 EEDATA EEPROM Data Register 0000 0000 38, 70 EECON2 EEPROM Control Register 2 (not a physical register) 0000 0000 38, 58, 67 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 38, 59, 68 IPR2 OSCFIP — — EEIP — LVDIP TMR3IP — 1--1 -11- 38, 83 PIR2 OSCFIF — — EEIF — LVDIF TMR3IF — 0--0 -00- 38, 79 PIE2 OSCFIE — — EEIE — LVDIE TMR3IE — 0--0 -00- 38, 81 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 38, 82 PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 38, 78 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 38, 80 OSCTUNE — — TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 --00 0000 38, 15 TRISB Data Direction Control Register for PORTB 1111 1111 38, 98 TRISA TRISA7(2) TRISA6(1) — Data Direction Control Register for PORTA 11-1 1111 38, 89 LATB Read/Write PORTB Data Latch xxxx xxxx 38, 98 LATA LATA<7>(2) LATA<6>(1) — Read/Write PORTA Data Latch xx-x xxxx 38, 89 PORTB Read PORTB pins, Write PORTB Data Latch xxxx xxxx 38, 98 PORTA RA7(2) RA6(1) RA5(4) Read PORTA pins, Write PORTA Data Latch xx0x 0000 38, 89 TABLE 5-2: REGISTER FILE SUMMARY (PIC18F1220/1320) (CONTINUED) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: Legend: x = unknown, u = unchanged, – = unimplemented, q = value depends on condition Note 1: RA6 and associated bits are configured as port pins in RCIO, ECIO and INTIO2 (with port function on RA6) Oscillator mode only and read ‘0’ in all other oscillator modes. 2: RA7 and associated bits are configured as port pins in INTIO2 Oscillator mode only and read ‘0’ in all other modes. 3: Bit 21 of the PC is only available in Test mode and Serial Programming modes. 4: The RA5 port bit is only available when MCLRE fuse (CONFIG3H<7>) is programmed to ‘0’. Otherwise, RA5 reads ‘0’. This bit is read-only.PIC18F1220/1320 DS39605F-page 52 © 2007 Microchip Technology Inc. 5.10 Access Bank The Access Bank is an architectural enhancement which is very useful for C compiler code optimization. The techniques used by the C compiler may also be useful for programs written in assembly. This data memory region can be used for: • Intermediate computational values • Local variables of subroutines • Faster context saving/switching of variables • Common variables • Faster evaluation/control of SFRs (no banking) The Access Bank is comprised of the last 128 bytes in Bank 15 (SFRs) and the first 128 bytes in Bank 0. These two sections will be referred to as Access RAM High and Access RAM Low, respectively. Figure 5-6 indicates the Access RAM areas. A bit in the instruction word specifies if the operation is to occur in the bank specified by the BSR register or in the Access Bank. This bit is denoted as the ‘a’ bit (for access bit). When forced in the Access Bank (a = 0), the last address in Access RAM Low is followed by the first address in Access RAM High. Access RAM High maps the Special Function Registers, so these registers can be accessed without any software overhead. This is useful for testing status flags and modifying control bits. 5.11 Bank Select Register (BSR) The need for a large general purpose memory space dictates a RAM banking scheme. The data memory is partitioned into as many as sixteen banks. When using direct addressing, the BSR should be configured for the desired bank. BSR<3:0> holds the upper 4 bits of the 12-bit RAM address. The BSR<7:4> bits will always read ‘0’s and writes will have no effect (see Figure 5-7). A MOVLB instruction has been provided in the instruction set to assist in selecting banks. If the currently selected bank is not implemented, any read will return all ‘0’s and all writes are ignored. The Status register bits will be set/cleared as appropriate for the instruction performed. Each Bank extends up to FFh (256 bytes). All data memory is implemented as static RAM. A MOVFF instruction ignores the BSR, since the 12-bit addresses are embedded into the instruction word. Section 5.12 “Indirect Addressing, INDF and FSR Registers” provides a description of indirect addressing, which allows linear addressing of the entire RAM space. FIGURE 5-7: DIRECT ADDRESSING Note 1: For register file map detail, see Table 5-1. 2: The access bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the registers of the Access Bank. 3: The MOVFF instruction embeds the entire 12-bit address in the instruction. Data Memory(1) Direct Addressing Bank Select(2) Location Select(3) BSR<3:0> 7 From Opcode 0 (3) 00h 01h 0Eh 0Fh Bank 0 Bank 1 Bank 14 Bank 15 1FFh 100h 0FFh 000h EFFh E00h FFFh F00h BSR<7:4> 000 0© 2007 Microchip Technology Inc. DS39605F-page 53 PIC18F1220/1320 5.12 Indirect Addressing, INDF and FSR Registers Indirect addressing is a mode of addressing data memory, where the data memory address in the instruction is not fixed. An FSR register is used as a pointer to the data memory location that is to be read or written. Since this pointer is in RAM, the contents can be modified by the program. This can be useful for data tables in the data memory and for software stacks. Figure 5-8 shows how the fetched instruction is modified prior to being executed. Indirect addressing is possible by using one of the INDF registers. Any instruction, using the INDF register, actually accesses the register pointed to by the File Select Register, FSR. Reading the INDF register itself, indirectly (FSR = 0), will read 00h. Writing to the INDF register indirectly, results in a no operation (NOP). The FSR register contains a 12-bit address, which is shown in Figure 5-9. The INDFn register is not a physical register. Addressing INDFn actually addresses the register whose address is contained in the FSRn register (FSRn is a pointer). This is indirect addressing. Example 5-5 shows a simple use of indirect addressing to clear the RAM in Bank 1 (locations 100h-1FFh) in a minimum number of instructions. EXAMPLE 5-5: HOW TO CLEAR RAM (BANK 1) USING INDIRECT ADDRESSING There are three indirect addressing registers. To address the entire data memory space (4096 bytes), these registers are 12-bit wide. To store the 12 bits of addressing information, two 8-bit registers are required: 1. FSR0: composed of FSR0H:FSR0L 2. FSR1: composed of FSR1H:FSR1L 3. FSR2: composed of FSR2H:FSR2L In addition, there are registers INDF0, INDF1 and INDF2, which are not physically implemented. Reading or writing to these registers activates indirect addressing, with the value in the corresponding FSR register being the address of the data. If an instruction writes a value to INDF0, the value will be written to the address pointed to by FSR0H:FSR0L. A read from INDF1 reads the data from the address pointed to by FSR1H:FSR1L. INDFn can be used in code anywhere an operand can be used. If INDF0, INDF1 or INDF2 are read indirectly via an FSR, all ‘0’s are read (zero bit is set). Similarly, if INDF0, INDF1 or INDF2 are written to indirectly, the operation will be equivalent to a NOP instruction and the Status bits are not affected. 5.12.1 INDIRECT ADDRESSING OPERATION Each FSR register has an INDF register associated with it, plus four additional register addresses. Performing an operation using one of these five registers determines how the FSR will be modified during indirect addressing. When data access is performed using one of the five INDFn locations, the address selected will configure the FSRn register to: • Do nothing to FSRn after an indirect access (no change) – INDFn • Auto-decrement FSRn after an indirect access (post-decrement) – POSTDECn • Auto-increment FSRn after an indirect access (post-increment) – POSTINCn • Auto-increment FSRn before an indirect access (pre-increment) – PREINCn • Use the value in the WREG register as an offset to FSRn. Do not modify the value of the WREG or the FSRn register after an indirect access (no change) – PLUSWn When using the auto-increment or auto-decrement features, the effect on the FSR is not reflected in the Status register. For example, if the indirect address causes the FSR to equal ‘0’, the Z bit will not be set. Auto-incrementing or auto-decrementing an FSR affects all 12 bits. That is, when FSRnL overflows from an increment, FSRnH will be incremented automatically. Adding these features allows the FSRn to be used as a stack pointer, in addition to its uses for table operations in data memory. Each FSR has an address associated with it that performs an indexed indirect access. When a data access to this INDFn location (PLUSWn) occurs, the FSRn is configured to add the signed value in the WREG register and the value in FSR to form the address before an indirect access. The FSR value is not changed. The WREG offset range is -128 to +127. If an FSR register contains a value that points to one of the INDFn, an indirect read will read 00h (zero bit is set), while an indirect write will be equivalent to a NOP (Status bits are not affected). If an indirect addressing write is performed when the target address is an FSRnH or FSRnL register, the data is written to the FSR register, but no pre- or post-increment/ decrement is performed. LFSR FSR0,0x100 ; NEXT CLRF POSTINC0 ; Clear INDF ; register then ; inc pointer BTFSS FSR0H, 1 ; All done with ; Bank1? GOTO NEXT ; NO, clear next CONTINUE ; YES, continue PIC18F1220/1320 DS39605F-page 54 © 2007 Microchip Technology Inc. FIGURE 5-8: INDIRECT ADDRESSING OPERATION FIGURE 5-9: INDIRECT ADDRESSING Opcode Address File Address = Access of an Indirect Addressing Register FSR Instruction Executed Instruction Fetched RAM Opcode File 12 12 12 BSR<3:0> 4 8 0h FFFh Note 1: For register file map detail, see Table 5-1. Data Memory(1) Indirect Addressing FSRnH:FSRnL 3 0 0FFFh 0000h Location Select 11 0 0 7© 2007 Microchip Technology Inc. DS39605F-page 55 PIC18F1220/1320 5.13 Status Register The Status register, shown in Register 5-2, contains the arithmetic status of the ALU. As with any other SFR, it can be the operand for any instruction. If the Status register is the destination for an instruction that affects the Z, DC, C, OV or N bits, the results of the instruction are not written; instead, the status is updated according to the instruction performed. Therefore, the result of an instruction with the Status register as its destination may be different than intended. As an example, CLRF STATUS will set the Z bit and leave the remaining Status bits unchanged (‘000u u1uu’). It is recommended that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the Status register, because these instructions do not affect the Z, C, DC, OV or N bits in the Status register. For other instructions that do not affect Status bits, see the instruction set summaries in Table 20-1. REGISTER 5-2: STATUS REGISTER Note: The C and DC bits operate as the borrow and digit borrow bits, respectively, in subtraction. U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x — — — N OV Z DC C bit 7 bit 0 bit 7-5 Unimplemented: Read as ‘0’ bit 4 N: Negative bit This bit is used for signed arithmetic (2’s complement). It indicates whether the result was negative (ALU MSB = 1). 1 = Result was negative 0 = Result was positive bit 3 OV: Overflow bit This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit magnitude, which causes the sign bit (bit 7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred bit 2 Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero bit 1 DC: Digit carry/borrow bit For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the 4th low-order bit of the result occurred 0 = No carry-out from the 4th low-order bit of the result Note: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the bit 4 or bit 3 of the source register. bit 0 C: Carry/borrow bit For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred Note: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the source register. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 56 © 2007 Microchip Technology Inc. 5.14 RCON Register The Reset Control (RCON) register contains flag bits that allow differentiation between the sources of a device Reset. These flags include the TO, PD, POR, BOR and RI bits. This register is readable and writable. REGISTER 5-3: RCON REGISTER Note 1: If the BOR configuration bit is set (Brownout Reset enabled), the BOR bit is ‘1’ on a Power-on Reset. After a Brown-out Reset has occurred, the BOR bit will be cleared and must be set by firmware to indicate the occurrence of the next Brown-out Reset. 2: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent Power-on Resets may be detected. R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN — — RI TO PD POR BOR bit 7 bit 0 bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) bit 6-5 Unimplemented: Read as ‘0’ bit 4 RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed (set by firmware only) 0 = The RESET instruction was executed causing a device Reset (must be set in software after a Brown-out Reset occurs) bit 3 TO: Watchdog Time-out Flag bit 1 = Set by power-up, CLRWDT instruction or SLEEP instruction 0 = A WDT time-out occurred bit 2 PD: Power-down Detection Flag bit 1 = Set by power-up or by the CLRWDT instruction 0 = Cleared by execution of the SLEEP instruction bit 1 POR: Power-on Reset Status bit 1 = A Power-on Reset has not occurred (set by firmware only) 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) bit 0 BOR: Brown-out Reset Status bit 1 = A Brown-out Reset has not occurred (set by firmware only) 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 57 PIC18F1220/1320 6.0 FLASH PROGRAM MEMORY The Flash program memory is readable, writable and erasable during normal operation over the entire VDD range. A read from program memory is executed on one byte at a time. A write to program memory is executed on blocks of 8 bytes at a time. Program memory is erased in blocks of 64 bytes at a time. A “Bulk Erase” operation may not be issued from user code. While writing or erasing program memory, instruction fetches cease until the operation is complete. The program memory cannot be accessed during the write or erase, therefore, code cannot execute. An internal programming timer terminates program memory writes and erases. A value written to program memory does not need to be a valid instruction. Executing a program memory location that forms an invalid instruction results in a NOP. 6.1 Table Reads and Table Writes In order to read and write program memory, there are two operations that allow the processor to move bytes between the program memory space and the data RAM: • Table Read (TBLRD) • Table Write (TBLWT) The program memory space is 16 bits wide, while the data RAM space is 8 bits wide. Table reads and table writes move data between these two memory spaces through an 8-bit register (TABLAT). Table read operations retrieve data from program memory and place it into TABLAT in the data RAM space. Figure 6-1 shows the operation of a table read with program memory and data RAM. Table write operations store data from TABLAT in the data memory space into holding registers in program memory. The procedure to write the contents of the holding registers into program memory is detailed in Section 6.5 “Writing to Flash Program Memory”. Figure 6-2 shows the operation of a table write with program memory and data RAM. Table operations work with byte entities. A table block containing data, rather than program instructions, is not required to be word aligned. Therefore, a table block can start and end at any byte address. If a table write is being used to write executable code into program memory, program instructions will need to be word aligned (TBLPTRL<0> = 0). The EEPROM on-chip timer controls the write and erase times. The write and erase voltages are generated by an on-chip charge pump rated to operate over the voltage range of the device for byte or word operations. FIGURE 6-1: TABLE READ OPERATION Table Pointer(1) Table Latch (8-bit) Program Memory TBLPTRH TBLPTRL TABLAT TBLPTRU Instruction: TBLRD* Note 1: Table Pointer points to a byte in program memory. Program Memory (TBLPTR)PIC18F1220/1320 DS39605F-page 58 © 2007 Microchip Technology Inc. FIGURE 6-2: TABLE WRITE OPERATION 6.2 Control Registers Several control registers are used in conjunction with the TBLRD and TBLWT instructions. These include the: • EECON1 register • EECON2 register • TABLAT register • TBLPTR registers 6.2.1 EECON1 AND EECON2 REGISTERS EECON1 is the control register for memory accesses. EECON2 is not a physical register. Reading EECON2 will read all ‘0’s. The EECON2 register is used exclusively in the memory write and erase sequences. Control bit, EEPGD, determines if the access will be to program or data EEPROM memory. When clear, operations will access the data EEPROM memory. When set, program memory is accessed. Control bit, CFGS, determines if the access will be to the configuration registers, or to program memory/data EEPROM memory. When set, subsequent operations access configuration registers. When CFGS is clear, the EEPGD bit selects either program Flash or data EEPROM memory. The FREE bit controls program memory erase operations. When the FREE bit is set, the erase operation is initiated on the next WR command. When FREE is clear, only writes are enabled. The WREN bit enables and disables erase and write operations. When set, erase and write operations are allowed. When clear, erase and write operations are disabled – the WR bit cannot be set while the WREN bit is clear. This process helps to prevent accidental writes to memory due to errant (unexpected) code execution. Firmware should keep the WREN bit clear at all times, except when starting erase or write operations. Once firmware has set the WR bit, the WREN bit may be cleared. Clearing the WREN bit will not affect the operation in progress. The WRERR bit is set when a write operation is interrupted by a Reset. In these situations, the user can check the WRERR bit and rewrite the location. It will be necessary to reload the data and address registers (EEDATA and EEADR) as these registers have cleared as a result of the Reset. Control bits, RD and WR, start read and erase/write operations, respectively. These bits are set by firmware and cleared by hardware at the completion of the operation. The RD bit cannot be set when accessing program memory (EEPGD = 1). Program memory is read using table read instructions. See Section 6.3 “Reading the Flash Program Memory” regarding table reads. Table Pointer(1) Table Latch (8-bit) TBLPTRH TBLPTRL TABLAT Program Memory (TBLPTR) TBLPTRU Instruction: TBLWT* Note 1: Table Pointer actually points to one of eight holding registers, the address of which is determined by TBLPTRL<2:0>. The process for physically writing data to the program memory array is discussed in Section 6.5 “Writing to Flash Program Memory”. Holding Registers Program Memory Note: Interrupt flag bit, EEIF in the PIR2 register, is set when the write is complete. It must be cleared in software.© 2007 Microchip Technology Inc. DS39605F-page 59 PIC18F1220/1320 REGISTER 6-1: EECON1 REGISTER R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD CFGS — FREE WRERR WREN WR RD bit 7 bit 0 bit 7 EEPGD: Flash Program or Data EEPROM Memory Select bit 1 = Access program Flash memory 0 = Access data EEPROM memory bit 6 CFGS: Flash Program/Data EE or Configuration Select bit 1 = Access configuration registers 0 = Access program Flash or data EEPROM memory bit 5 Unimplemented: Read as ‘0’ bit 4 FREE: Flash Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation – TBLPTR<5:0> are ignored) 0 = Perform write only bit 3 WRERR: EEPROM Error Flag bit 1 = A write operation was prematurely terminated (any Reset during self-timed programming) 0 = The write operation completed normally Note: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition. bit 2 WREN: Write Enable bit 1 = Allows erase or write cycles 0 = Inhibits erase or write cycles bit 1 WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle. (The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle completed bit 0 RD: Read Control bit 1 = Initiates a memory read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1.) 0 = Read completed Legend: R = Readable bit S = Settable only U = Unimplemented bit, read as ‘0’ W = Writable bit -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 60 © 2007 Microchip Technology Inc. 6.2.2 TABLAT – TABLE LATCH REGISTER The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The table latch is used to hold 8-bit data during data transfers between program memory and data RAM. 6.2.3 TBLPTR – TABLE POINTER REGISTER The Table Pointer (TBLPTR) addresses a byte within the program memory. The TBLPTR is comprised of three SFR registers: Table Pointer Upper Byte, Table Pointer High Byte and Table Pointer Low Byte (TBLPTRU:TBLPTRH:TBLPTRL). These three registers join to form a 22-bit wide pointer. The low-order 21 bits allow the device to address up to 2 Mbytes of program memory space. Setting the 22nd bit allows access to the device ID, the user ID and the configuration bits. The Table Pointer (TBLPTR) register is used by the TBLRD and TBLWT instructions. These instructions can update the TBLPTR in one of four ways based on the table operation. These operations are shown in Table 6-1. These operations on the TBLPTR only affect the low-order 21 bits. 6.2.4 TABLE POINTER BOUNDARIES TBLPTR is used in reads, writes and erases of the Flash program memory. When a TBLRD is executed, all 22 bits of the Table Pointer determine which byte is read from program or configuration memory into TABLAT. When a TBLWT is executed, the three LSbs of the Table Pointer (TBLPTR<2:0>) determine which of the eight program memory holding registers is written to. When the timed write to program memory (long write) begins, the 19 MSbs of the Table Pointer (TBLPTR<21:3>) will determine which program memory block of 8 bytes is written to (TBLPTR<2:0> are ignored). For more detail, see Section 6.5 “Writing to Flash Program Memory”. When an erase of program memory is executed, the 16 MSbs of the Table Pointer (TBLPTR<21:6>) point to the 64-byte block that will be erased. The Least Significant bits (TBLPTR<5:0>) are ignored. Figure 6-3 describes the relevant boundaries of TBLPTR based on Flash program memory operations. TABLE 6-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS FIGURE 6-3: TABLE POINTER BOUNDARIES BASED ON OPERATION Example Operation on Table Pointer TBLRD* TBLWT* TBLPTR is not modified TBLRD*+ TBLWT*+ TBLPTR is incremented after the read/write TBLRD*- TBLWT*- TBLPTR is decremented after the read/write TBLRD+* TBLWT+* TBLPTR is incremented before the read/write 21 16 15 8 7 0 ERASE – TBLPTR<21:6> LONG WRITE – TBLPTR<21:3> READ or WRITE – TBLPTR<21:0> TBLPTRU TBLPTRH TBLPTRL© 2007 Microchip Technology Inc. DS39605F-page 61 PIC18F1220/1320 6.3 Reading the Flash Program Memory The TBLRD instruction is used to retrieve data from program memory and place it into data RAM. Table reads from program memory are performed one byte at a time. TBLPTR points to a byte address in program space. Executing a TBLRD instruction places the byte pointed to into TABLAT. In addition, TBLPTR can be modified automatically for the next table read operation. The internal program memory is typically organized by words. The Least Significant bit of the address selects between the high and low bytes of the word. Figure 6-4 shows the interface between the internal program memory and the TABLAT. FIGURE 6-4: READS FROM FLASH PROGRAM MEMORY EXAMPLE 6-1: READING A FLASH PROGRAM MEMORY WORD Odd (High) Byte Program Memory Even (Low) Byte TABLAT TBLPTR Instruction Register (IR) Read Register LSB = 1 TBLPTR LSB = 0 MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base MOVWF TBLPTRU ; address of the word MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL READ_WORD TBLRD*+ ; read into TABLAT and increment TBLPTR MOVFW TABLAT ; get data MOVWF WORD_EVEN TBLRD*+ ; read into TABLAT and increment TBLPTR MOVFW TABLAT ; get data MOVWF WORD_ODDPIC18F1220/1320 DS39605F-page 62 © 2007 Microchip Technology Inc. 6.4 Erasing Flash Program Memory The minimum erase block size is 32 words or 64 bytes under firmware control. Only through the use of an external programmer, or through ICSP control, can larger blocks of program memory be bulk erased. Word erase in Flash memory is not supported. When initiating an erase sequence from the microcontroller itself, a block of 64 bytes of program memory is erased. The Most Significant 16 bits of the TBLPTR<21:6> point to the block being erased. TBLPTR<5:0> are ignored. The EECON1 register commands the erase operation. The EEPGD bit must be set to point to the Flash program memory. The CFGS bit must be clear to access program Flash and data EEPROM memory. The WREN bit must be set to enable write operations. The FREE bit is set to select an erase operation. The WR bit is set as part of the required instruction sequence (as shown in Example 6-2) and starts the actual erase operation. It is not necessary to load the TABLAT register with any data as it is ignored. For protection, the write initiate sequence using EECON2 must be used. A long write is necessary for erasing the internal Flash. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. 6.4.1 FLASH PROGRAM MEMORY ERASE SEQUENCE The sequence of events for erasing a block of internal program memory location is: 1. Load Table Pointer with address of row being erased. 2. Set the EECON1 register for the erase operation: • set EEPGD bit to point to program memory; • clear the CFGS bit to access program memory; • set WREN bit to enable writes; • set FREE bit to enable the erase. 3. Disable interrupts. 4. Write 55h to EECON2. 5. Write AAh to EECON2. 6. Set the WR bit. This will begin the row erase cycle. 7. The CPU will stall for duration of the erase (about 2 ms using internal timer). 8. Execute a NOP. 9. Re-enable interrupts. EXAMPLE 6-2: ERASING A FLASH PROGRAM MEMORY ROW MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL ERASE_ROW BSF EECON1, EEPGD ; point to FLASH program memory BSF EECON1, WREN ; enable write to memory BSF EECON1, FREE ; enable Row Erase operation BCF INTCON, GIE ; disable interrupts MOVLW 55h MOVWF EECON2 ; write 55H Required MOVLW AAh Sequence MOVWF EECON2 ; write AAH BSF EECON1, WR ; start erase (CPU stall) NOP BSF INTCON, GIE ; re-enable interrupts© 2007 Microchip Technology Inc. DS39605F-page 63 PIC18F1220/1320 6.5 Writing to Flash Program Memory The programming block size is 4 words or 8 bytes. Word or byte programming is not supported. Table writes are used internally to load the holding registers needed to program the Flash memory. There are 8 holding registers used by the table writes for programming. Since the Table Latch (TABLAT) is only a single byte, the TBLWT instruction must be executed 8 times for each programming operation. All of the table write operations will essentially be short writes, because only the holding registers are written. At the end of updating 8 registers, the EECON1 register must be written to, to start the programming operation with a long write. The long write is necessary for programming the internal Flash. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. FIGURE 6-5: TABLE WRITES TO FLASH PROGRAM MEMORY 6.5.1 FLASH PROGRAM MEMORY WRITE SEQUENCE The sequence of events for programming an internal program memory location should be: 1. Read 64 bytes into RAM. 2. Update data values in RAM as necessary. 3. Load Table Pointer with address being erased. 4. Do the row erase procedure (see Section 6.4.1 “Flash Program Memory Erase Sequence”). 5. Load Table Pointer with address of first byte being written. 6. Write the first 8 bytes into the holding registers with auto-increment. 7. Set the EECON1 register for the write operation: • set EEPGD bit to point to program memory; • clear the CFGS bit to access program memory; • set WREN bit to enable byte writes. 8. Disable interrupts. 9. Write 55h to EECON2. 10. Write AAh to EECON2. 11. Set the WR bit. This will begin the write cycle. 12. The CPU will stall for duration of the write (about 2 ms using internal timer). 13. Execute a NOP. 14. Re-enable interrupts. 15. Repeat steps 6-14 seven times to write 64 bytes. 16. Verify the memory (table read). This procedure will require about 18 ms to update one row of 64 bytes of memory. An example of the required code is given in Example 6-3. Holding Register TABLAT Holding Register TBLPTR = xxxxx7 Holding Register TBLPTR = xxxxx1 Holding Register TBLPTR = xxxxx0 8 8 8 8 Write Register TBLPTR = xxxxx2 Program MemoryPIC18F1220/1320 DS39605F-page 64 © 2007 Microchip Technology Inc. EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY MOVLW D'64 ; number of bytes in erase block MOVWF COUNTER MOVLW BUFFER_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW ; 6 LSB = 0 MOVWF TBLPTRL READ_BLOCK TBLRD*+ ; read into TABLAT, and inc MOVF TABLAT, W ; get data MOVWF POSTINC0 ; store data and increment FSR0 DECFSZ COUNTER ; done? GOTO READ_BLOCK ; repeat MODIFY_WORD MOVLW DATA_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW DATA_ADDR_LOW MOVWF FSR0L MOVLW NEW_DATA_LOW ; update buffer word and increment FSR0 MOVWF POSTINC0 MOVLW NEW_DATA_HIGH ; update buffer word MOVWF INDF0 ERASE_BLOCK MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW ; 6 LSB = 0 MOVWF TBLPTRL BCF EECON1, CFGS ; point to PROG/EEPROM memory BSF EECON1, EEPGD ; point to FLASH program memory BSF EECON1, WREN ; enable write to memory BSF EECON1, FREE ; enable Row Erase operation BCF INTCON, GIE ; disable interrupts MOVLW 55h ; Required sequence MOVWF EECON2 ; write 55H MOVLW AAh MOVWF EECON2 ; write AAH BSF EECON1, WR ; start erase (CPU stall) NOP BSF INTCON, GIE ; re-enable interrupts WRITE_BUFFER_BACK MOVLW 8 ; number of write buffer groups of 8 bytes MOVWF COUNTER_HI MOVLW BUFFER_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L PROGRAM_LOOP MOVLW 8 ; number of bytes in holding register MOVWF COUNTER© 2007 Microchip Technology Inc. DS39605F-page 65 PIC18F1220/1320 EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED) 6.5.2 WRITE VERIFY Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 6.5.3 UNEXPECTED TERMINATION OF WRITE OPERATION If a write is terminated by an unplanned event, such as loss of power or an unexpected Reset, the memory location just programmed should be verified and reprogrammed if needed. The WRERR bit is set when a write operation is interrupted by a MCLR Reset, or a WDT Time-out Reset during normal operation. In these situations, users can check the WRERR bit and rewrite the location. 6.6 Flash Program Operation During Code Protection See Section 19.0 “Special Features of the CPU” for details on code protection of Flash program memory. TABLE 6-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY WRITE_WORD_TO_HREGS MOVF POSTINC0, W ; get low byte of buffer data and increment FSR0 MOVWF TABLAT ; present data to table latch TBLWT+* ; short write ; to internal TBLWT holding register, increment TBLPTR DECFSZ COUNTER ; loop until buffers are full GOTO WRITE_WORD_TO_HREGS PROGRAM_MEMORY BCF INTCON, GIE ; disable interrupts MOVLW 55h ; required sequence MOVWF EECON2 ; write 55H MOVLW AAh MOVWF EECON2 ; write AAH BSF EECON1, WR ; start program (CPU stall) NOP BSF INTCON, GIE ; re-enable interrupts DECFSZ COUNTER_HI ; loop until done GOTO PROGRAM_LOOP BCF EECON1, WREN ; disable write to memory Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other Resets TBLPTRU — — bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 --00 0000 TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 0000 0000 TBLPTRL Program Memory Table Pointer High Byte (TBLPTR<7:0>) 0000 0000 0000 0000 TABLAT Program Memory Table Latch 0000 0000 0000 0000 INTCON GIE/GIEH PEIE/GIEL TMR0IE INTE RBIE TMR0IF INTF RBIF 0000 000x 0000 000u EECON2 EEPROM Control Register 2 (not a physical register) — — EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 uu-0 u000 IPR2 OSCFIP — — EEIP — LVDIP TMR3IP — 1--1 -11- 1--1 -11- PIR2 OSCFIF — — EEIF — LVDIF TMR3IF — 0--0 -00- 0--0 -00- PIE2 OSCFIE — — EEIE — LVDIE TMR3IE — 0--0 -00- 0--0 -00- Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.PIC18F1220/1320 DS39605F-page 66 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 67 PIC18F1220/1320 7.0 DATA EEPROM MEMORY The data EEPROM is readable and writable during normal operation over the entire VDD range. The data memory is not directly mapped in the register file space. Instead, it is indirectly addressed through the Special Function Registers (SFR). There are four SFRs used to read and write the program and data EEPROM memory. These registers are: • EECON1 • EECON2 • EEDATA • EEADR The EEPROM data memory allows byte read and write. When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and EEADR holds the address of the EEPROM location being accessed. These devices have 256 bytes of data EEPROM with an address range from 00h to FFh. The EEPROM data memory is rated for high erase/ write cycle endurance. A byte write automatically erases the location and writes the new data (erasebefore-write). The write time is controlled by an on-chip timer. The write time will vary with voltage and temperature, as well as from chip to chip. Please refer to parameter D122 (Table 22-1 in Section 22.0 “Electrical Characteristics”) for exact limits. 7.1 EEADR The address register can address 256 bytes of data EEPROM. 7.2 EECON1 and EECON2 Registers EECON1 is the control register for memory accesses. EECON2 is not a physical register. Reading EECON2 will read all ‘0’s. The EECON2 register is used exclusively in the memory write and erase sequences. Control bit, EEPGD, determines if the access will be to program or data EEPROM memory. When clear, operations will access the data EEPROM memory. When set, program memory is accessed. Control bit, CFGS, determines if the access will be to the configuration registers or to program memory/data EEPROM memory. When set, subsequent operations access configuration registers. When CFGS is clear, the EEPGD bit selects either program Flash or data EEPROM memory. The WREN bit enables and disables erase and write operations. When set, erase and write operations are allowed. When clear, erase and write operations are disabled – the WR bit cannot be set while the WREN bit is clear. This mechanism helps to prevent accidental writes to memory due to errant (unexpected) code execution. Firmware should keep the WREN bit clear at all times, except when starting erase or write operations. Once firmware has set the WR bit, the WREN bit may be cleared. Clearing the WREN bit will not affect the operation in progress. The WRERR bit is set when a write operation is interrupted by a Reset. In these situations, the user can check the WRERR bit and rewrite the location. It is necessary to reload the data and address registers (EEDATA and EEADR), as these registers have cleared as a result of the Reset. Control bits, RD and WR, start read and erase/write operations, respectively. These bits are set by firmware and cleared by hardware at the completion of the operation. The RD bit cannot be set when accessing program memory (EEPGD = 1). Program memory is read using table read instructions. See Section 6.1 “Table Reads and Table Writes” regarding table reads. Note: Interrupt flag bit, EEIF in the PIR2 register, is set when write is complete. It must be cleared in software.PIC18F1220/1320 DS39605F-page 68 © 2007 Microchip Technology Inc. REGISTER 7-1: EECON1 REGISTER R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD CFGS — FREE WRERR WREN WR RD bit 7 bit 0 bit 7 EEPGD: Flash Program or Data EEPROM Memory Select bit 1 = Access program Flash memory 0 = Access data EEPROM memory bit 6 CFGS: Flash Program/Data EEPROM or Configuration Select bit 1 = Access configuration or calibration registers 0 = Access program Flash or data EEPROM memory bit 5 Unimplemented: Read as ‘0’ bit 4 FREE: Flash Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only bit 3 WRERR: EEPROM Error Flag bit 1 = A write operation was prematurely terminated (MCLR or WDT Reset during self-timed erase or program operation) 0 = The write operation completed normally Note: When a WRERR occurs, the EEPGD or FREE bits are not cleared. This allows tracing of the error condition. bit 2 WREN: Erase/Write Enable bit 1 = Allows erase/write cycles 0 = Inhibits erase/write cycles bit 1 WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle, or a program memory erase cycle, or write cycle. (The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle is completed bit 0 RD: Read Control bit 1 = Initiates a memory read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1.) 0 = Read completed Legend: R = Readable bit S = Settable only U = Unimplemented bit, read as ‘0’ W = Writable bit -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 69 PIC18F1220/1320 7.3 Reading the Data EEPROM Memory To read a data memory location, the user must write the address to the EEADR register, clear the EEPGD control bit (EECON1<7>) and then set control bit, RD (EECON1<0>). The data is available for the very next instruction cycle; therefore, the EEDATA register can be read by the next instruction. EEDATA will hold this value until another read operation, or until it is written to by the user (during a write operation). 7.4 Writing to the Data EEPROM Memory To write an EEPROM data location, the address must first be written to the EEADR register and the data written to the EEDATA register. The sequence in Example 7-2 must be followed to initiate the write cycle. The write will not begin if this sequence is not exactly followed (write 55h to EECON2, write AAh to EECON2, then set WR bit) for each byte. It is strongly recommended that interrupts be disabled during this code segment. Additionally, the WREN bit in EECON1 must be set to enable writes. This mechanism prevents accidental writes to data EEPROM due to unexpected code execution (i.e., runaway programs). The WREN bit should be kept clear at all times, except when updating the EEPROM. The WREN bit is not cleared by hardware. After a write sequence has been initiated, EECON1, EEADR and EEDATA cannot be modified. The WR bit will be inhibited from being set unless the WREN bit is set. The WREN bit must be set on a previous instruction. Both WR and WREN cannot be set with the same instruction. At the completion of the write cycle, the WR bit is cleared in hardware and the EEPROM Interrupt Flag bit (EEIF) is set. The user may either enable this interrupt or poll this bit. EEIF must be cleared by software. 7.5 Write Verify Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 7.6 Protection Against Spurious Write There are conditions when the device may not want to write to the data EEPROM memory. To protect against spurious EEPROM writes, various mechanisms have been built-in. On power-up, the WREN bit is cleared. Also, the Power-up Timer (72 ms duration) prevents EEPROM write. The write initiate sequence and the WREN bit together help prevent an accidental write during brown-out, power glitch or software malfunction. EXAMPLE 7-1: DATA EEPROM READ EXAMPLE 7-2: DATA EEPROM WRITE MOVLW DATA_EE_ADDR ; MOVWF EEADR ; Data Memory Address to read BCF EECON1, EEPGD ; Point to DATA memory BSF EECON1, RD ; EEPROM Read MOVF EEDATA, W ; W = EEDATA MOVLW DATA_EE_ADDR ; MOVWF EEADR ; Data Memory Address to write MOVLW DATA_EE_DATA ; MOVWF EEDATA ; Data Memory Value to write BCF EECON1, EEPGD ; Point to DATA memory BSF EECON1, WREN ; Enable writes BCF INTCON, GIE ; Disable Interrupts MOVLW 55h ; Required MOVWF EECON2 ; Write 55h Sequence MOVLW AAh ; MOVWF EECON2 ; Write AAh BSF EECON1, WR ; Set WR bit to begin write BSF INTCON, GIE ; Enable Interrupts SLEEP ; Wait for interrupt to signal write complete BCF EECON1, WREN ; Disable writesPIC18F1220/1320 DS39605F-page 70 © 2007 Microchip Technology Inc. 7.7 Operation During Code-Protect Data EEPROM memory has its own code-protect bits in configuration words. External read and write operations are disabled if either of these mechanisms are enabled. The microcontroller itself can both read and write to the internal data EEPROM, regardless of the state of the code-protect configuration bit. Refer to Section 19.0 “Special Features of the CPU” for additional information. 7.8 Using the Data EEPROM The data EEPROM is a high endurance, byte addressable array that has been optimized for the storage of frequently changing information (e.g., program variables or other data that are updated often). Frequently changing values will typically be updated more often than specification D124. If this is not the case, an array refresh must be performed. For this reason, variables that change infrequently (such as constants, IDs, calibration, etc.) should be stored in Flash program memory. A simple data EEPROM refresh routine is shown in Example 7-3. EXAMPLE 7-3: DATA EEPROM REFRESH ROUTINE TABLE 7-1: REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY Note: If data EEPROM is only used to store constants and/or data that changes rarely, an array refresh is likely not required. See specification D124. CLRF EEADR ; Start at address 0 BCF EECON1, CFGS ; Set for memory BCF EECON1, EEPGD ; Set for Data EEPROM BCF INTCON, GIE ; Disable interrupts BSF EECON1, WREN ; Enable writes Loop ; Loop to refresh array BSF EECON1, RD ; Read current address MOVLW 55h ; MOVWF EECON2 ; Write 55h MOVLW AAh ; MOVWF EECON2 ; Write AAh BSF EECON1, WR ; Set WR bit to begin write BTFSC EECON1, WR ; Wait for write to complete BRA $-2 INCFSZ EEADR, F ; Increment address BRA Loop ; Not zero, do it again BCF EECON1, WREN ; Disable writes BSF INTCON, GIE ; Enable interrupts Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INTE RBIE TMR0IF INTF RBIF 0000 000x 0000 000u EEADR EEPROM Address Register 0000 0000 0000 0000 EEDATA EEPROM Data Register 0000 0000 0000 0000 EECON2 EEPROM Control Register 2 (not a physical register) — — EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 uu-0 u000 IPR2 OSCFIP — — EEIP — LVDIP TMR3IP — 1--1 -11- 1--1 -11- PIR2 OSCFIF — — EEIF — LVDIF TMR3IF — 0--0 -00- 0--0 -00- PIE2 OSCFIE — — EEIE — LVDIE TMR3IE — 0--0 -00- 0--0 -00- Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.© 2007 Microchip Technology Inc. DS39605F-page 71 PIC18F1220/1320 8.0 8 x 8 HARDWARE MULTIPLIER 8.1 Introduction An 8 x 8 hardware multiplier is included in the ALU of the PIC18F1220/1320 devices. By making the multiply a hardware operation, it completes in a single instruction cycle. This is an unsigned multiply that gives a 16-bit result. The result is stored into the 16-bit product register pair (PRODH:PRODL). The multiplier does not affect any flags in the Status register. Making the 8 x 8 multiplier execute in a single cycle gives the following advantages: • Higher computational throughput • Reduces code size requirements for multiply algorithms The performance increase allows the device to be used in applications previously reserved for Digital Signal Processors. Table 8-1 shows a performance comparison between Enhanced devices using the single-cycle hardware multiply and performing the same function without the hardware multiply. TABLE 8-1: PERFORMANCE COMPARISON 8.2 Operation Example 8-1 shows the sequence to do an 8 x 8 unsigned multiply. Only one instruction is required when one argument of the multiply is already loaded in the WREG register. Example 8-2 shows the sequence to do an 8 x 8 signed multiply. To account for the sign bits of the arguments, each argument’s Most Significant bit (MSb) is tested and the appropriate subtractions are done. EXAMPLE 8-1: 8 x 8 UNSIGNED MULTIPLY ROUTINE EXAMPLE 8-2: 8 x 8 SIGNED MULTIPLY ROUTINE Routine Multiply Method Program Memory (Words) Cycles (Max) Time @ 40 MHz @ 10 MHz @ 4 MHz 8 x 8 unsigned Without hardware multiply 13 69 6.9 μs 27.6 μs 69 μs Hardware multiply 1 1 100 ns 400 ns 1 μs 8 x 8 signed Without hardware multiply 33 91 9.1 μs 36.4 μs 91 μs Hardware multiply 6 6 600 ns 2.4 μs 6 μs 16 x 16 unsigned Without hardware multiply 21 242 24.2 μs 96.8 μs 242 μs Hardware multiply 28 28 2.8 μs 11.2 μs 28 μs 16 x 16 signed Without hardware multiply 52 254 25.4 μs 102.6 μs 254 μs Hardware multiply 35 40 4 μs 16 μs 40 μs MOVF ARG1, W ; MULWF ARG2 ; ARG1 * ARG2 -> ; PRODH:PRODL MOVF ARG1, W MULWF ARG2 ; ARG1 * ARG2 -> ; PRODH:PRODL BTFSC ARG2, SB ; Test Sign Bit SUBWF PRODH, F ; PRODH = PRODH ; - ARG1 MOVF ARG2, W BTFSC ARG1, SB ; Test Sign Bit SUBWF PRODH, F ; PRODH = PRODH ; - ARG2 PIC18F1220/1320 DS39605F-page 72 © 2007 Microchip Technology Inc. Example 8-3 shows the sequence to do a 16 x 16 unsigned multiply. Equation 8-1 shows the algorithm that is used. The 32-bit result is stored in four registers, RES3:RES0. EQUATION 8-1: 16 x 16 UNSIGNED MULTIPLICATION ALGORITHM EXAMPLE 8-3: 16 x 16 UNSIGNED MULTIPLY ROUTINE Example 8-4 shows the sequence to do a 16 x 16 signed multiply. Equation 8-2 shows the algorithm used. The 32-bit result is stored in four registers, RES3:RES0. To account for the sign bits of the arguments, each argument pairs’ Most Significant bit (MSb) is tested and the appropriate subtractions are done. EQUATION 8-2: 16 x 16 SIGNED MULTIPLICATION ALGORITHM EXAMPLE 8-4: 16 x 16 SIGNED MULTIPLY ROUTINE MOVF ARG1L, W MULWF ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL MOVFF PRODH, RES1 ; MOVFF PRODL, RES0 ; ; MOVF ARG1H, W MULWF ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL MOVFF PRODH, RES3 ; MOVFF PRODL, RES2 ; ; MOVF ARG1L, W MULWF ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3,F ; ; MOVF ARG1H, W ; MULWF ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; RES3:RES0 = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28 ) + (ARG1L • ARG2H • 28 ) + (ARG1L • ARG2L) MOVF ARG1L, W MULWF ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL MOVFF PRODH, RES1 ; MOVFF PRODL, RES0 ; ; MOVF ARG1H, W MULWF ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL MOVFF PRODH, RES3 ; MOVFF PRODL, RES2 ; ; MOVF ARG1L, W MULWF ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; MOVF ARG1H, W ; MULWF ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; BTFSS ARG2H, 7 ; ARG2H:ARG2L neg? BRA SIGN_ARG1 ; no, check ARG1 MOVF ARG1L, W ; SUBWF RES2 ; MOVF ARG1H, W ; SUBWFB RES3 ; SIGN_ARG1 BTFSS ARG1H, 7 ; ARG1H:ARG1L neg? BRA CONT_CODE ; no, done MOVF ARG2L, W ; SUBWF RES2 ; MOVF ARG2H, W ; SUBWFB RES3 ; CONT_CODE : RES3:RES0 = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28) + (ARG1L • ARG2H • 28) + (ARG1L • ARG2L) + (-1 • ARG2H<7> • ARG1H:ARG1L • 216) + (-1 • ARG1H<7> • ARG2H:ARG2L • 216) © 2007 Microchip Technology Inc. DS39605F-page 73 PIC18F1220/1320 9.0 INTERRUPTS The PIC18F1220/1320 devices have multiple interrupt sources and an interrupt priority feature that allows each interrupt source to be assigned a high priority level or a low priority level. The high priority interrupt vector is at 000008h and the low priority interrupt vector is at 000018h. High priority interrupt events will interrupt any low priority interrupts that may be in progress. There are ten registers which are used to control interrupt operation. These registers are: • RCON • INTCON • INTCON2 • INTCON3 • PIR1, PIR2 • PIE1, PIE2 • IPR1, IPR2 It is recommended that the Microchip header files supplied with MPLAB® IDE be used for the symbolic bit names in these registers. This allows the assembler/ compiler to automatically take care of the placement of these bits within the specified register. In general, each interrupt source has three bits to control its operation. The functions of these bits are: • Flag bit to indicate that an interrupt event occurred • Enable bit that allows program execution to branch to the interrupt vector address when the flag bit is set • Priority bit to select high priority or low priority (INT0 has no priority bit and is always high priority) The interrupt priority feature is enabled by setting the IPEN bit (RCON<7>). When interrupt priority is enabled, there are two bits which enable interrupts globally. Setting the GIEH bit (INTCON<7>) enables all interrupts that have the priority bit set (high priority). Setting the GIEL bit (INTCON<6>) enables all interrupts that have the priority bit cleared (low priority). When the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address 000008h or 000018h, depending on the priority bit setting. Individual interrupts can be disabled through their corresponding enable bits. When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PIC mid-range devices. In Compatibility mode, the interrupt priority bits for each source have no effect. INTCON<6> is the PEIE bit, which enables/disables all peripheral interrupt sources. INTCON<7> is the GIE bit, which enables/disables all interrupt sources. All interrupts branch to address 000008h in Compatibility mode. When an interrupt is responded to, the global interrupt enable bit is cleared to disable further interrupts. If the IPEN bit is cleared, this is the GIE bit. If interrupt priority levels are used, this will be either the GIEH or GIEL bit. High priority interrupt sources can interrupt a low priority interrupt. Low priority interrupts are not processed while high priority interrupts are in progress. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (000008h or 000018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bits must be cleared in software before re-enabling interrupts to avoid recursive interrupts. The “return from interrupt” instruction, RETFIE, exits the interrupt routine and sets the GIE bit (GIEH or GIEL, if priority levels are used), which re-enables interrupts. For external interrupt events, such as the INT pins or the PORTB input change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding enable bit or the GIE bit. Note: Do not use the MOVFF instruction to modify any of the interrupt control registers while any interrupt is enabled. Doing so may cause erratic microcontroller behavior.PIC18F1220/1320 DS39605F-page 74 © 2007 Microchip Technology Inc. FIGURE 9-1: INTERRUPT LOGIC TMR0IE GIEH/GIE GIEL/PEIE Wake-up if in Low-Power Mode Interrupt to CPU Vector to Location 0008h INT2IF INT2IE INT2IP INT1IF INT1IE INT1IP TMR0IF TMR0IE TMR0IP INT0IF INT0IE RBIF RBIE RBIP IPEN TMR0IF TMR0IP INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP RBIF RBIE RBIP INT0IF INT0IE GIEL\PEIE Interrupt to CPU Vector to Location IPEN IPEN 0018h INT0IF INT0IE INT0IF INT0IE ADIF ADIE ADIP RCIF RCIE RCIP Additional Peripheral Interrupts ADIF ADIE ADIP High Priority Interrupt Generation Low Priority Interrupt Generation RCIF RCIE RCIP Additional Peripheral Interrupts GIE\GIEH© 2007 Microchip Technology Inc. DS39605F-page 75 PIC18F1220/1320 9.1 INTCON Registers The INTCON registers are readable and writable registers, which contain various enable, priority and flag bits. REGISTER 9-1: INTCON REGISTER Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF bit 7 bit 0 bit 7 GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts When IPEN = 1: 1 = Enables all high priority interrupts 0 = Disables all interrupts bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts When IPEN = 1: 1 = Enables all low priority peripheral interrupts 0 = Disables all low priority peripheral interrupts bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 overflow interrupt 0 = Disables the TMR0 overflow interrupt bit 4 INT0IE: INT0 External Interrupt Enable bit 1 = Enables the INT0 external interrupt 0 = Disables the INT0 external interrupt bit 3 RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow bit 1 INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared in software) 0 = The INT0 external interrupt did not occur bit 0 RBIF: RB Port Change Interrupt Flag bit 1 = At least one of the RB7:RB4 pins changed state (must be cleared in software) 0 = None of the RB7:RB4 pins have changed state Note: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 76 © 2007 Microchip Technology Inc. REGISTER 9-2: INTCON2 REGISTER R/W-1 R/W-1 R/W-1 R/W-1 U-0 R/W-1 U-0 R/W-1 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP bit 7 bit 0 bit 7 RBPU: PORTB Pull-up Enable bit 1 = All PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values bit 6 INTEDG0: External Interrupt 0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 5 INTEDG1: External Interrupt 1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 4 INTEDG2: External Interrupt 2 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 3 Unimplemented: Read as ‘0’ bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 Unimplemented: Read as ‘0’ bit 0 RBIP: RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.© 2007 Microchip Technology Inc. DS39605F-page 77 PIC18F1220/1320 REGISTER 9-3: INTCON3 REGISTER R/W-1 R/W-1 U-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF bit 7 bit 0 bit 7 INT2IP: INT2 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 INT1IP: INT1 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 Unimplemented: Read as ‘0’ bit 4 INT2IE: INT2 External Interrupt Enable bit 1 = Enables the INT2 external interrupt 0 = Disables the INT2 external interrupt bit 3 INT1IE: INT1 External Interrupt Enable bit 1 = Enables the INT1 external interrupt 0 = Disables the INT1 external interrupt bit 2 Unimplemented: Read as ‘0’ bit 1 INT2IF: INT2 External Interrupt Flag bit 1 = The INT2 external interrupt occurred (must be cleared in software) 0 = The INT2 external interrupt did not occur bit 0 INT1IF: INT1 External Interrupt Flag bit 1 = The INT1 external interrupt occurred (must be cleared in software) 0 = The INT1 external interrupt did not occur Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.PIC18F1220/1320 DS39605F-page 78 © 2007 Microchip Technology Inc. 9.2 PIR Registers The PIR registers contain the individual flag bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Request (Flag) registers (PIR1, PIR2). REGISTER 9-4: PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1 Note 1: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the Global Interrupt Enable bit, GIE (INTCON<7>). 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt and after servicing that interrupt. U-0 R/W-0 R-0 R-0 U-0 R/W-0 R/W-0 R/W-0 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete bit 5 RCIF: EUSART Receive Interrupt Flag bit 1 = The EUSART receive buffer, RCREG, is full (cleared when RCREG is read) 0 = The EUSART receive buffer is empty bit 4 TXIF: EUSART Transmit Interrupt Flag bit 1 = The EUSART transmit buffer, TXREG, is empty (cleared when TXREG is written) 0 = The EUSART transmit buffer is full bit 3 Unimplemented: Read as ‘0’ bit 2 CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode. bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = TMR1 register did not overflow Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 79 PIC18F1220/1320 REGISTER 9-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2 R/W-0 U-0 U-0 R/W-0 U-0 R/W-0 R/W-0 U-0 OSCFIF — — EEIF — LVDIF TMR3IF — bit 7 bit 0 bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit 1 = System oscillator failed, clock input has changed to INTOSC (must be cleared in software) 0 = System clock operating bit 6-5 Unimplemented: Read as ‘0’ bit 4 EEIF: Data EEPROM/Flash Write Operation Interrupt Flag bit 1 = The write operation is complete (must be cleared in software) 0 = The write operation is not complete or has not been started bit 3 Unimplemented: Read as ‘0’ bit 2 LVDIF: Low-Voltage Detect Interrupt Flag bit 1 = A low-voltage condition occurred (must be cleared in software) 0 = The device voltage is above the Low-Voltage Detect trip point bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared in software) 0 = TMR3 register did not overflow bit 0 Unimplemented: Read as ‘0’ Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 80 © 2007 Microchip Technology Inc. 9.3 PIE Registers The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Enable registers (PIE1, PIE2). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts. REGISTER 9-6: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1 U-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt bit 5 RCIE: EUSART Receive Interrupt Enable bit 1 = Enables the EUSART receive interrupt 0 = Disables the EUSART receive interrupt bit 4 TXIE: EUSART Transmit Interrupt Enable bit 1 = Enables the EUSART transmit interrupt 0 = Disables the EUSART transmit interrupt bit 3 Unimplemented: Read as ‘0’ bit 2 CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 81 PIC18F1220/1320 REGISTER 9-7: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2 R/W-0 U-0 U-0 R/W-0 U-0 R/W-0 R/W-0 U-0 OSCFIE — — EEIE — LVDIE TMR3IE — bit 7 bit 0 bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit 1 = Enabled 0 = Disabled bit 6-5 Unimplemented: Read as ‘0’ bit 4 EEIE: Data EEPROM/Flash Write Operation Interrupt Enable bit 1 = Enabled 0 = Disabled bit 3 Unimplemented: Read as ‘0’ bit 2 LVDIE: Low-Voltage Detect Interrupt Enable bit 1 = Enabled 0 = Disabled bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enabled 0 = Disabled bit 0 Unimplemented: Read as ‘0’ Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 82 © 2007 Microchip Technology Inc. 9.4 IPR Registers The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Priority registers (IPR1, IPR2). Using the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set. REGISTER 9-8: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1 U-0 R/W-1 R/W-1 R/W-1 U-0 R/W-1 R/W-1 R/W-1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 RCIP: EUSART Receive Interrupt Priority bit 1 = High priority 0 = Low priority bit 4 TXIP: EUSART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 Unimplemented: Read as ‘0’ bit 2 CCP1IP: CCP1 Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 83 PIC18F1220/1320 REGISTER 9-9: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2 R/W-1 U-0 U-0 R/W-1 U-0 R/W-1 R/W-1 U-0 OSCFIP — — EEIP — LVDIP TMR3IP — bit 7 bit 0 bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit 1 = High priority 0 = Low priority bit 6-5 Unimplemented: Read as ‘0’ bit 4 EEIP: Data EEPROM/Flash Write Operation Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 Unimplemented: Read as ‘0’ bit 2 LVDIP: Low-Voltage Detect Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 Unimplemented: Read as ‘0’ Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 84 © 2007 Microchip Technology Inc. 9.5 RCON Register The RCON register contains bits used to determine the cause of the last Reset or wake-up from a low-power mode. RCON also contains the bit that enables interrupt priorities (IPEN). REGISTER 9-10: RCON REGISTER R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN — — RI TO PD POR BOR bit 7 bit 0 bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) bit 6-5 Unimplemented: Read as ‘0’ bit 4 RI: RESET Instruction Flag bit For details of bit operation, see Register 5-3. bit 3 TO: Watchdog Time-out Flag bit For details of bit operation, see Register 5-3. bit 2 PD: Power-down Detection Flag bit For details of bit operation, see Register 5-3. bit 1 POR: Power-on Reset Status bit For details of bit operation, see Register 5-3. bit 0 BOR: Brown-out Reset Status bit For details of bit operation, see Register 5-3. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 85 PIC18F1220/1320 9.6 INTn Pin Interrupts External interrupts on the RB0/INT0, RB1/INT1 and RB2/INT2 pins are edge-triggered: either rising if the corresponding INTEDGx bit is set in the INTCON2 register, or falling if the INTEDGx bit is clear. When a valid edge appears on the RBx/INTx pin, the corresponding flag bit, INTxF, is set. This interrupt can be disabled by clearing the corresponding enable bit, INTxE. Flag bit, INTxF, must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1 and INT2) can wake-up the processor from low-power modes if bit INTxE was set prior to going into low-power modes. If the Global Interrupt Enable bit, GIE, is set, the processor will branch to the interrupt vector following wake-up. Interrupt priority for INT1 and INT2 is determined by the value contained in the interrupt priority bits, INT1IP (INTCON3<6>) and INT2IP (INTCON3<7>). There is no priority bit associated with INT0. It is always a high priority interrupt source. 9.7 TMR0 Interrupt In 8-bit mode (which is the default), an overflow (FFh → 00h) in the TMR0 register will set flag bit, TMR0IF. In 16-bit mode, an overflow (FFFFh → 0000h) in the TMR0H:TMR0L registers will set flag bit, TMR0IF. The interrupt can be enabled/disabled by setting/clearing enable bit, TMR0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit, TMR0IP (INTCON2<2>). See Section 11.0 “Timer0 Module” for further details on the Timer0 module. 9.8 PORTB Interrupt-on-Change An input change on PORTB<7:4> sets flag bit, RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit, RBIE (INTCON<3>). Interrupt priority for PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RBIP (INTCON2<0>). 9.9 Context Saving During Interrupts During interrupts, the return PC address is saved on the stack. Additionally, the WREG, Status and BSR registers are saved on the fast return stack. If a fast return from interrupt is not used (see Section 5.3 “Fast Register Stack”), the user may need to save the WREG, Status and BSR registers on entry to the Interrupt Service Routine. Depending on the user’s application, other registers may also need to be saved. Example 9-1 saves and restores the WREG, Status and BSR registers during an Interrupt Service Routine. EXAMPLE 9-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM MOVWF W_TEMP ; W_TEMP is in virtual bank MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere MOVFF BSR, BSR_TEMP ; BSR_TMEP located anywhere ; ; USER ISR CODE ; MOVFF BSR_TEMP, BSR ; Restore BSR MOVF W_TEMP, W ; Restore WREG MOVFF STATUS_TEMP, STATUS ; Restore STATUSPIC18F1220/1320 DS39605F-page 86 © 2007 Microchip Technology Inc. NOTES: © 2007 Microchip Technology Inc. DS39605F-page 87 PIC18F1220/1320 10.0 I/O PORTS Depending on the device selected and features enabled, there are up to five ports available. Some pins of the I/O ports are multiplexed with an alternate function from the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Each port has three registers for its operation. These registers are: • TRIS register (data direction register) • PORT register (reads the levels on the pins of the device) • LAT register (output latch) The Data Latch (LATA) register is useful for readmodify-write operations on the value that the I/O pins are driving. A simplified model of a generic I/O port without the interfaces to other peripherals is shown in Figure 10-1. FIGURE 10-1: GENERIC I/O PORT OPERATION 10.1 PORTA, TRISA and LATA Registers PORTA is an 8-bit wide, bidirectional port. The corresponding data direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). Reading the PORTA register reads the status of the pins, whereas writing to it will write to the port latch. The Data Latch register (LATA) is also memory mapped. Read-modify-write operations on the LATA register read and write the latched output value for PORTA. The RA4 pin is multiplexed with the Timer0 module clock input to become the RA4/T0CKI pin. The sixth pin of PORTA (MCLR/VPP/RA5) is an input only pin. Its operation is controlled by the MCLRE configuration bit in Configuration Register 3H (CONFIG3H<7>). When selected as a port pin (MCLRE = 0), it functions as a digital input only pin; as such, it does not have TRIS or LAT bits associated with its operation. Otherwise, it functions as the device’s Master Clear input. In either configuration, RA5 also functions as the programming voltage input during programming. Pins RA6 and RA7 are multiplexed with the main oscillator pins; they are enabled as oscillator or I/O pins by the selection of the main oscillator in Configuration Register 1H (see Section 19.1 “Configuration Bits” for details). When they are not used as port pins, RA6 and RA7 and their associated TRIS and LAT bits are read as ‘0’. The other PORTA pins are multiplexed with analog inputs, the analog VREF+ and VREF- inputs and the LVD input. The operation of pins RA3:RA0 as A/D converter inputs is selected by clearing/setting the control bits in the ADCON1 register (A/D Control Register 1). The RA4/T0CKI pin is a Schmitt Trigger input and an open-drain output. All other PORTA pins have TTL input levels and full CMOS output drivers. The TRISA register controls the direction of the RA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs. EXAMPLE 10-1: INITIALIZING PORTA Data Bus WR LAT WR TRIS RD Port Data Latch TRIS Latch RD TRIS Input Buffer I/O pin(1) D Q CK D Q CK EN Q D EN RD LAT or Port Note 1: I/O pins have diode protection to VDD and VSS. Note: On a Power-on Reset, RA5 is enabled as a digital input only if Master Clear functionality is disabled. Note: On a Power-on Reset, RA3:RA0 are configured as analog inputs and read as ‘0’. RA4 is always a digital pin. CLRF PORTA ; Initialize PORTA by ; clearing output ; data latches CLRF LATA ; Alternate method ; to clear output ; data latches MOVLW 0x7F ; Configure A/D MOVWF ADCON1 ; for digital inputs MOVLW 0xD0 ; Value used to ; initialize data ; direction MOVWF TRISA ; Set RA<3:0> as outputs ; RA<7:4> as inputsPIC18F1220/1320 DS39605F-page 88 © 2007 Microchip Technology Inc. FIGURE 10-2: BLOCK DIAGRAM OF RA3:RA0 PINS FIGURE 10-3: BLOCK DIAGRAM OF OSC2/CLKO/RA6 PIN FIGURE 10-4: BLOCK DIAGRAM OF RA4/T0CKI PIN FIGURE 10-5: BLOCK DIAGRAM OF OSC1/CLKI/RA7 PIN Data Bus Q D EN P N WR LATA WR TRISA Data Latch TRIS Latch RD TRISA RD PORTA VSS VDD I/O pin(1) Note 1: I/O pins have protection diodes to VDD and VSS. Analog Input Mode To A/D Converter and LVD Modules RD LATA or PORTA D Q CK Q D Q CK Q Schmitt Trigger Input Buffer Data Bus D Q CK Q Q D EN P N WR LATA WR Data Latch TRIS Latch RD RD PORTA VSS VDD I/O pin(1) Note 1: I/O pins have protection diodes to VDD and VSS. or PORTA RD LATA RA6 Enable ECIO or Enable RCIO TRISA D Q CK Q TRISA Schmitt Trigger Input Buffer Data Bus WR TRISA RD PORTA Data Latch TRIS Latch Schmitt Trigger Input Buffer N VSS I/O pin(1) TMR0 Clock Input D Q CK Q D Q CK Q EN Q D EN RD LATA WR LATA or PORTA Note 1: I/O pins have protection diodes to VDD and VSS. RD TRISA Data Bus D Q CK Q Q D EN P N WR LATA WR Data Latch TRIS Latch RD RD PORTA VSS VDD I/O pin(1) Note 1: I/O pins have protection diodes to VDD and VSS. or PORTA RD LATA Enable RA7 TRISA D Q CK Q TRISA RA7 Enable To Oscillator Schmitt Trigger Input Buffer© 2007 Microchip Technology Inc. DS39605F-page 89 PIC18F1220/1320 FIGURE 10-6: MCLR/VPP/RA5 PIN BLOCK DIAGRAM TABLE 10-1: PORTA FUNCTIONS TABLE 10-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA MCLR/VPP/RA5 Data Bus RD PORTA RD LATA Schmitt Trigger MCLRE RD TRISA Q D EN Latch Filter Low-Level MCLR Detect High-Voltage Detect Internal MCLR HV Name Bit# Buffer Function RA0/AN0 bit 0 ST Input/output port pin or analog input. RA1/AN1/LVDIN bit 1 ST Input/output port pin, analog input or Low-Voltage Detect input. RA2/AN2/VREF- bit 2 ST Input/output port pin, analog input or VREF-. RA3/AN3/VREF+ bit 3 ST Input/output port pin, analog input or VREF+. RA4/T0CKI bit 4 ST Input/output port pin or external clock input for Timer0. Output is open-drain type. MCLR/VPP/RA5 bit 5 ST Master Clear input or programming voltage input (if MCLR is enabled); input only port pin or programming voltage input (if MCLR is disabled). OSC2/CLKO/RA6 bit 6 ST OSC2, clock output or I/O pin. OSC1/CLKI/RA7 bit 7 ST OSC1, clock input or I/O pin. Legend: TTL = TTL input, ST = Schmitt Trigger input Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets PORTA RA7(1) RA6(1) RA5(2) RA4 RA3 RA2 RA1 RA0 xx0x 0000 uu0u 0000 LATA LATA7(1) LATA6(1) — LATA Data Output Register xx-x xxxx uu-u uuuu TRISA TRISA7(1) TRISA6(1) — PORTA Data Direction Register 11-1 1111 11-1 1111 ADCON1 — PCFG6 PCFG5 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 -000 0000 -000 0000 Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by PORTA. Note 1: RA7:RA6 and their associated latch and data direction bits are enabled as I/O pins based on oscillator configuration; otherwise, they are read as ‘0’. 2: RA5 is an input only if MCLR is disabled.PIC18F1220/1320 DS39605F-page 90 © 2007 Microchip Technology Inc. 10.2 PORTB, TRISB and LATB Registers PORTB is an 8-bit wide, bidirectional port. The corresponding data direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATB) is also memory mapped. Read-modify-write operations on the LATB register read and write the latched output value for PORTB. EXAMPLE 10-2: INITIALIZING PORTB Pins RB0-RB2 are multiplexed with INT0-INT2; pins RB0, RB1 and RB4 are multiplexed with A/D inputs; pins RB1 and RB4 are multiplexed with EUSART; and pins RB2, RB3, RB6 and RB7 are multiplexed with ECCP. Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit, RBPU (INTCON2<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. Four of the PORTB pins (RB7:RB4) have an interrupton-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB4 pin configured as an output is excluded from the interrupton-change comparison). The input pins (of RB7:RB4) are compared with the old value latched on the last read of PORTB. The “mismatch” outputs of RB7:RB4 are OR’ed together to generate the RB Port Change Interrupt with Flag bit, RBIF (INTCON<0>). This interrupt can wake the device from Sleep. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) Any read or write of PORTB (except with the MOVFF instruction). This will end the mismatch condition. b) Clear flag bit, RBIF. A mismatch condition will continue to set flag bit, RBIF. Reading PORTB will end the mismatch condition and allow flag bit, RBIF, to be cleared. The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. FIGURE 10-7: BLOCK DIAGRAM OF RB0/AN4/INT0 PIN Note: On a Power-on Reset, RB4:RB0 are configured as analog inputs by default and read as ‘0’; RB7:RB5 are configured as digital inputs. CLRF PORTB ; Initialize PORTB by ; clearing output ; data latches CLRF LATB ; Alternate method ; to clear output ; data latches MOVLW 0x70 ; Set RB0, RB1, RB4 as MOVWF ADCON1 ; digital I/O pins MOVLW 0xCF ; Value used to ; initialize data ; direction MOVWF TRISB ; Set RB<3:0> as inputs ; RB<5:4> as outputs ; RB<7:6> as inputs Data Latch RBPU(2) P VDD Data Bus WR LATB WR TRISB RD TRISB RD PORTB Weak Pull-up INTx I/O pin(1) Schmitt Trigger Buffer TRIS Latch RD LATB or PORTB Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). To A/D Converter Analog Input Mode TTL Input Buffer D Q CK D Q CK EN Q D EN© 2007 Microchip Technology Inc. DS39605F-page 91 PIC18F1220/1320 FIGURE 10-8: BLOCK DIAGRAM OF RB1/AN5/TX/CK/INT1 PIN Data Latch RBPU(2) P VDD D Q CK D Q CK Q D EN Data Bus WR LATB WR TRISB RD TRISB RD PORTB Weak Pull-up RD PORTB RB1 pin(1) TRIS Latch RD LATB or PORTB Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). To A/D Converter INT1/CK Input Analog Input Mode 1 0 TX/CK Data EUSART Enable Schmitt Trigger Input Buffer TX/CK TRIS Analog Input Mode TTL Input BufferPIC18F1220/1320 DS39605F-page 92 © 2007 Microchip Technology Inc. FIGURE 10-9: BLOCK DIAGRAM OF RB2/P1B/INT2 PIN Data Latch RBPU(2) P VDD D Q CK D Q CK Q D EN Data Bus WR LATB or WR TRISB RD TRISB RD PORTB Weak Pull-up RD PORTB RB2 pin(1) TTL Input Buffer TRIS Latch RD LATB PORTB P1B Data 1 0 Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). P1B Enable INT2 Input Schmitt Trigger P1B/D Tri-State Auto-Shutdown© 2007 Microchip Technology Inc. DS39605F-page 93 PIC18F1220/1320 FIGURE 10-10: BLOCK DIAGRAM OF RB3/CCP1/P1A PIN Data Bus WR LATB or WR TRISB Data Latch TRIS Latch RD TRISB D Q CK Q Q D EN ECCP1/P1A Data Out 1 0 D Q CK Q P N VDD VSS RD PORTB ECCP1 Input RB3 pin PORTB RD LATB Schmitt Trigger VDD Weak Pull-up P RBPU(2) TTL Input Buffer Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). 3: ECCP1 pin output enable active for any PWM mode and Compare mode, where CCP1M<3:0> = 1000 or 1001. 4: ECCP1 pin input enable active for Capture mode only. ECCP1(3) pin Output Enable P1A/C Tri-State Auto-Shutdown ECCP1(4) pin Input EnablePIC18F1220/1320 DS39605F-page 94 © 2007 Microchip Technology Inc. FIGURE 10-11: BLOCK DIAGRAM OF RB4/AN6/RX/DT/KBI0 PIN Data Bus WR LATB or WR TRISB Data Latch TRIS Latch RD TRISB D Q CK Q Q D EN DT Data 1 0 D Q CK Q RD PORTB RB4 pin PORTB RD LATB RBPU(2) P Weak Pull-up Q1 From other Q D EN Set RBIF RB7:RB4 pins RD PORTB Q3 To A/D Converter EUSART Enabled TTL Input Buffer Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). DT TRIS Analog Input Mode RX/DT Input Analog Input Mode Schmitt Trigger VDD© 2007 Microchip Technology Inc. DS39605F-page 95 PIC18F1220/1320 FIGURE 10-12: BLOCK DIAGRAM OF RB5/PGM/KBI1 PIN Data Latch From other RBPU(2) P VDD I/O pin(1) D Q CK D Q CK Q D EN Q D EN Data Bus WR LATB WR TRISB Set RBIF TRIS Latch RD TRISB RD PORTB RB7:RB5 and Weak Pull-up RD PORTB Latch TTL Input Buffer ST Buffer RB7:RB5 in Serial Programming Mode Q3 Q1 RD LATB or PORTB Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). RB4 pinsPIC18F1220/1320 DS39605F-page 96 © 2007 Microchip Technology Inc. FIGURE 10-13: BLOCK DIAGRAM OF RB6/PGC/T1OSO/T13CKI/P1C/KBI2 PIN Data Bus WR LATB or WR TRISB Data Latch TRIS Latch RD TRISB D Q CK Q Q D EN P1C Data 1 0 D Q CK Q RD PORTB RB6 pin PORTB RD LATB Schmitt Trigger RBPU(2) P Weak Pull-up Q1 From other Q D EN Set RBIF RB7:RB4 pins RD PORTB Q3 PGC From RB7 pin Timer1 Oscillator T1OSCEN T13CKI Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). TTL Buffer ECCP1 P1C/D Enable P1B/D Tri-State Auto-Shutdown VDD© 2007 Microchip Technology Inc. DS39605F-page 97 PIC18F1220/1320 FIGURE 10-14: BLOCK DIAGRAM OF RB7/PGD/T1OSI/P1D/KBI3 PIN Data Bus WR LATB or WR TRISB Data Latch TRIS Latch RD TRISB D Q CK Q Q D EN P1D Data 1 0 D Q CK Q RD PORTB RB7 pin PORTB RD LATB Schmitt Trigger To RB6 pin RBPU(2) P Weak Pull-up Q1 From other Q D EN Set RBIF RB7:RB4 pins RD PORTB Q3 PGD ECCP1 P1C/D Enable TTL Input Buffer Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>). P1B/D Tri-State Auto-Shutdown T1OSCEN VDDPIC18F1220/1320 DS39605F-page 98 © 2007 Microchip Technology Inc. TABLE 10-3: PORTB FUNCTIONS TABLE 10-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB Name Bit# Buffer Function RB0/AN4/INT0 bit 0 TTL(1)/ST(2) Input/output port pin, analog input or external interrupt input 0. RB1/AN5/TX/CK/INT1 bit 1 TTL(1)/ST(2) Input/output port pin, analog input, Enhanced USART Asynchronous Transmit, Addressable USART Synchronous Clock or external interrupt input 1. RB2/P1B/INT2 bit 2 TTL(1)/ST(2) Input/output port pin or external interrupt input 2. Internal software programmable weak pull-up. RB3/CCP1/P1A bit 3 TTL(1)/ST(3) Input/output port pin or Capture1 input/Compare1 output/ PWM output. Internal software programmable weak pull-up. RB4/AN6/RX/DT/KBI0 bit 4 TTL(1)/ST(4) Input/output port pin (with interrupt-on-change), analog input, Enhanced USART Asynchronous Receive or Addressable USART Synchronous Data. RB5/PGM/KBI1 bit 5 TTL(1)/ST(5) Input/output port pin (with interrupt-on-change). Internal software programmable weak pull-up. Low-Voltage ICSP enable pin. RB6/PGC/T1OSO/T13CKI/ P1C/KBI2 bit 6 TTL(1)/ST(5,6) Input/output port pin (with interrupt-on-change), Timer1/ Timer3 clock input or Timer1oscillator output. Internal software programmable weak pull-up. Serial programming clock. RB7/PGD/T1OSI/P1D/KBI3 bit 7 TTL(1)/ST(5) Input/output port pin (with interrupt-on-change) or Timer1 oscillator input. Internal software programmable weak pull-up. Serial programming data. Legend: TTL = TTL input, ST = Schmitt Trigger input Note 1: This buffer is a TTL input when configured as a port input pin. 2: This buffer is a Schmitt Trigger input when configured as the external interrupt. 3: This buffer is a Schmitt Trigger input when configured as the CCP1 input. 4: This buffer is a Schmitt Trigger input when used as EUSART receive input. 5: This buffer is a Schmitt Trigger input when used in Serial Programming mode. 6: This buffer is a TTL input when used as the T13CKI input. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxq qqqq uuuu uuuu LATB LATB Data Output Register xxxx xxxx uuuu uuuu TRISB PORTB Data Direction Register 1111 1111 1111 1111 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP 1111 -1-1 1111 -1-1 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 11-0 0-00 ADCON1 — PCFG6 PCFG5 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 -000 0000 -000 0000 Legend: x = unknown, u = unchanged, q = value depends on condition. Shaded cells are not used by PORTB.© 2007 Microchip Technology Inc. DS39605F-page 99 PIC18F1220/1320 11.0 TIMER0 MODULE The Timer0 module has the following features: • Software selectable as an 8-bit or 16-bit timer/ counter • Readable and writable • Dedicated 8-bit software programmable prescaler • Clock source selectable to be external or internal • Interrupt-on-overflow from FFh to 00h in 8-bit mode and FFFFh to 0000h in 16-bit mode • Edge select for external clock Figure 11-1 shows a simplified block diagram of the Timer0 module in 8-bit mode and Figure 11-2 shows a simplified block diagram of the Timer0 module in 16-bit mode. The T0CON register (Register 11-1) is a readable and writable register that controls all the aspects of Timer0, including the prescale selection. REGISTER 11-1: T0CON: TIMER0 CONTROL REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 bit 7 bit 0 bit 7 TMR0ON: Timer0 On/Off Control bit 1 = Enables Timer0 0 = Stops Timer0 bit 6 T08BIT: Timer0 8-bit/16-bit Control bit 1 = Timer0 is configured as an 8-bit timer/counter 0 = Timer0 is configured as a 16-bit timer/counter bit 5 T0CS: Timer0 Clock Source Select bit 1 = Transition on T0CKI pin 0 = Internal instruction cycle clock (CLKO) bit 4 T0SE: Timer0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin bit 3 PSA: Timer0 Prescaler Assignment bit 1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler. 0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output. bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits 111 = 1:256 Prescale value 110 = 1:128 Prescale value 101 = 1:64 Prescale value 100 = 1:32 Prescale value 011 = 1:16 Prescale value 010 = 1:8 Prescale value 001 = 1:4 Prescale value 000 = 1:2 Prescale value Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 100 © 2007 Microchip Technology Inc. FIGURE 11-1: TIMER0 BLOCK DIAGRAM IN 8-BIT MODE FIGURE 11-2: TIMER0 BLOCK DIAGRAM IN 16-BIT MODE Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale. RA4/T0CKI T0SE 0 1 1 0 T0CS FOSC/4 Programmable Prescaler Sync with Internal Clocks TMR0 (2 TCY Delay) Data Bus 8 PSA T0PS2, T0PS1, T0PS0 Set Interrupt Flag bit TMR0IF on Overflow 3 pin Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale. T0SE 0 1 1 0 T0CS FOSC/4 Programmable Prescaler Sync with Internal Clocks TMR0L (2 TCY Delay) Data Bus<7:0> 8 PSA T0PS2, T0PS1, T0PS0 Set Interrupt Flag bit TMR0IF on Overflow 3 TMR0 TMR0H High Byte 8 8 8 Read TMR0L Write TMR0L RA4/T0CKI pin© 2007 Microchip Technology Inc. DS39605F-page 101 PIC18F1220/1320 11.1 Timer0 Operation Timer0 can operate as a timer or as a counter. Timer mode is selected by clearing the T0CS bit. In Timer mode, the Timer0 module will increment every instruction cycle (without prescaler). If the TMR0 register is written, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0 register. Counter mode is selected by setting the T0CS bit. In Counter mode, Timer0 will increment either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit (T0SE). Clearing the T0SE bit selects the rising edge. When an external clock input is used for Timer0, it must meet certain requirements. The requirements ensure the external clock can be synchronized with the internal phase clock (TOSC). Also, there is a delay in the actual incrementing of Timer0 after synchronization. 11.2 Prescaler An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not readable or writable. The PSA and T0PS2:T0PS0 bits determine the prescaler assignment and prescale ratio. Clearing bit PSA will assign the prescaler to the Timer0 module. When the prescaler is assigned to the Timer0 module, prescale values of 1:2, 1:4, ..., 1:256 are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0 register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, x, ..., etc.) will clear the prescaler count. 11.2.1 SWITCHING PRESCALER ASSIGNMENT The prescaler assignment is fully under software control (i.e., it can be changed “on-the-fly” during program execution). 11.3 Timer0 Interrupt The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF bit. The interrupt can be masked by clearing the TMR0IE bit. The TMR0IF bit must be cleared in software by the Timer0 module Interrupt Service Routine before re-enabling this interrupt. The TMR0 interrupt cannot awaken the processor from Low-Power Sleep mode, since the timer requires clock cycles even when T0CS is set. 11.4 16-Bit Mode Timer Reads and Writes TMR0H is not the high byte of the timer/counter in 16-bit mode, but is actually a buffered version of the high byte of Timer0 (refer to Figure 11-2). The high byte of the Timer0 counter/timer is not directly readable nor writable. TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16 bits of Timer0, without having to verify that the read of the high and low byte were valid due to a rollover between successive reads of the high and low byte. A write to the high byte of Timer0 must also take place through the TMR0H Buffer register. Timer0 high byte is updated with the contents of TMR0H when a write occurs to TMR0L. This allows all 16 bits of Timer0 to be updated at once. TABLE 11-1: REGISTERS ASSOCIATED WITH TIMER0 Note: Writing to TMR0 when the prescaler is assigned to Timer0 will clear the prescaler count, but will not change the prescaler assignment. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets TMR0L Timer0 Module Low Byte Register xxxx xxxx uuuu uuuu TMR0H Timer0 Module High Byte Register 0000 0000 0000 0000 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 1111 1111 TRISA RA7(1) RA6(1) — PORTA Data Direction Register 11-1 1111 11-1 1111 Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by Timer0. Note 1: RA6 and RA7 are enabled as I/O pins, depending on the oscillator mode selected in Configuration Word 1H.PIC18F1220/1320 DS39605F-page 102 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 103 PIC18F1220/1320 12.0 TIMER1 MODULE The Timer1 module timer/counter has the following features: • 16-bit timer/counter (two 8-bit registers: TMR1H and TMR1L) • Readable and writable (both registers) • Internal or external clock select • Interrupt-on-overflow from FFFFh to 0000h • Reset from CCP module special event trigger • Status of system clock operation Figure 12-1 is a simplified block diagram of the Timer1 module. Register 12-1 details the Timer1 Control register. This register controls the operating mode of the Timer1 module and contains the Timer1 Oscillator Enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit, TMR1ON (T1CON<0>). The Timer1 oscillator can be used as a secondary clock source in power managed modes. When the T1RUN bit is set, the Timer1 oscillator is providing the system clock. If the Fail-Safe Clock Monitor is enabled and the Timer1 oscillator fails while providing the system clock, polling the T1RUN bit will indicate whether the clock is being provided by the Timer1 oscillator or another source. Timer1 can also be used to provide Real-Time Clock (RTC) functionality to applications, with only a minimal addition of external components and code overhead. REGISTER 12-1: T1CON: TIMER1 CONTROL REGISTER R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON bit 7 bit 0 bit 7 RD16: 16-bit Read/Write Mode Enable bit 1 = Enables register read/write of TImer1 in one 16-bit operation 0 = Enables register read/write of Timer1 in two 8-bit operations bit 6 T1RUN: Timer1 System Clock Status bit 1 = System clock is derived from Timer1 oscillator 0 = System clock is derived from another source bit 5-4 T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 3 T1OSCEN: Timer1 Oscillator Enable bit 1 = Timer1 oscillator is enabled 0 = Timer1 oscillator is shut off The oscillator inverter and feedback resistor are turned off to eliminate power drain. bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. bit 1 TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RB6/PGC/T1OSO/T13CKI/P1C/KBI2 (on the rising edge) 0 = Internal clock (Fosc/4) bit 0 TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 104 © 2007 Microchip Technology Inc. 12.1 Timer1 Operation Timer1 can operate in one of these modes: • As a timer • As a synchronous counter • As an asynchronous counter The operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). When TMR1CS = 0, Timer1 increments every instruction cycle. When TMR1CS = 1, Timer1 increments on every rising edge of the external clock input, or the Timer1 oscillator, if enabled. When the Timer1 oscillator is enabled (T1OSCEN is set), the RB7/PGD/T1OSI/P1D/KBI3 and RB6/T1OSO/ T13CKI/P1C/KBI2 pins become inputs. That is, the TRISB7:TRISB6 values are ignored and the pins read as ‘0’. Timer1 also has an internal “Reset input”. This Reset can be generated by the CCP module (see Section 15.4.4 “Special Event Trigger”). FIGURE 12-1: TIMER1 BLOCK DIAGRAM FIGURE 12-2: TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE TMR1H TMR1L T1SYNC TMR1CS T1CKPS1:T1CKPS0 Peripheral Clocks FOSC/4 Internal Clock TMR1ON On/Off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 TMR1IF Overflow TMR1 CLR CCP Special Event Trigger T1OSCEN Enable Oscillator(1) T1OSC Interrupt Flag bit Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. T1OSI T13CKI/T1OSO Timer 1 TMR1L T1OSC T1SYNC TMR1CS T1CKPS1:T1CKPS0 Peripheral Clocks T1OSCEN Enable Oscillator(1) TMR1IF Overflow Interrupt FOSC/4 Internal Clock TMR1ON on/off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 T13CKI/T1OSO T1OSI TMR1 Flag bit Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. High Byte Data Bus<7:0> 8 TMR1H 8 8 8 Read TMR1L Write TMR1L CLR CCP Special Event Trigger© 2007 Microchip Technology Inc. DS39605F-page 105 PIC18F1220/1320 12.2 Timer1 Oscillator A crystal oscillator circuit is built-in between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting control bit, T1OSCEN (T1CON<3>). The oscillator is a low-power oscillator rated for 32 kHz crystals. It will continue to run during all power managed modes. The circuit for a typical LP oscillator is shown in Figure 12-3. Table 12-1 shows the capacitor selection for the Timer1 oscillator. The user must provide a software time delay to ensure proper start-up of the Timer1 oscillator. FIGURE 12-3: EXTERNAL COMPONENTS FOR THE TIMER1 LP OSCILLATOR TABLE 12-1: CAPACITOR SELECTION FOR THE TIMER OSCILLATOR Note: The Timer1 oscillator shares the T1OSI and T1OSO pins with the PGD and PGC pins used for programming and debugging. When using the Timer1 oscillator, In-Circuit Serial Programming (ICSP) may not function correctly (high voltage or low voltage), or the In-Circuit Debugger (ICD) may not communicate with the controller. As a result of using either ICSP or ICD, the Timer1 crystal may be damaged. If ICSP or ICD operations are required, the crystal should be disconnected from the circuit (disconnect either lead), or installed after programming. The oscillator loading capacitors may remain in-circuit during ICSP or ICD operation. Osc Type Freq C1 C2 LP 32 kHz 22 pF(1) 22 pF(1) Note 1: Microchip suggests this value as a starting point in validating the oscillator circuit. Oscillator operation should then be tested to ensure expected performance under all expected conditions (VDD and temperature). 2: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Capacitor values are for design guidance only. Note: See the Notes with Table 12-1 for additional information about capacitor selection. C1 C2 XTAL PIC18FXXXX PGD/T1OSI PGC/T1OSO 32.768 kHz 22 pF 22 pF PGD PGC PIC18F1220/1320 DS39605F-page 106 © 2007 Microchip Technology Inc. 12.3 Timer1 Oscillator Layout Considerations The Timer1 oscillator circuit draws very little power during operation. Due to the low-power nature of the oscillator, it may also be sensitive to rapidly changing signals in close proximity. The oscillator circuit, shown in Figure 12-3, should be located as close as possible to the microcontroller. There should be no circuits passing within the oscillator circuit boundaries other than VSS or VDD. If a high-speed circuit must be located near the oscillator (such as the CCP1 pin in output compare or PWM mode, or the primary oscillator using the OSC2 pin), a grounded guard ring around the oscillator circuit, as shown in Figure 12-4, may be helpful when used on a single sided PCB, or in addition to a ground plane. FIGURE 12-4: OSCILLATOR CIRCUIT WITH GROUNDED GUARD RING 12.4 Timer1 Interrupt The TMR1 register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The Timer1 interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR1IF (PIR1<0>). This interrupt can be enabled/disabled by setting/clearing Timer1 Interrupt Enable bit, TMR1IE (PIE1<0>). 12.5 Resetting Timer1 Using a CCP Trigger Output If the CCP module is configured in Compare mode to generate a “special event trigger” (CCP1M3:CCP1M0 = 1011), this signal will reset Timer1 and start an A/D conversion, if the A/D module is enabled (see Section 15.4.4 “Special Event Trigger” for more information). Timer1 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer1 is running in Asynchronous Counter mode, this Reset operation may not work. In the event that a write to Timer1 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPR1H:CCPR1L register pair effectively becomes the period register for Timer1. 12.6 Timer1 16-Bit Read/Write Mode Timer1 can be configured for 16-bit reads and writes (see Figure 12-2). When the RD16 control bit (T1CON<7>) is set, the address for TMR1H is mapped to a buffer register for the high byte of Timer1. A read from TMR1L will load the contents of the high byte of Timer1 into the Timer1 high byte buffer. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, is valid, due to a rollover between reads. A write to the high byte of Timer1 must also take place through the TMR1H Buffer register. Timer1 high byte is updated with the contents of TMR1H when a write occurs to TMR1L. This allows a user to write all 16 bits to both the high and low bytes of Timer1 at once. The high byte of Timer1 is not directly readable or writable in this mode. All reads and writes must take place through the Timer1 High Byte Buffer register. Writes to TMR1H do not clear the Timer1 prescaler. The prescaler is only cleared on writes to TMR1L. RA1 RA4 RB0 MCLR VSS RA2 RA3 Note: Not drawn to scale. RB2 OSC1 RB5 OSC2 VDD RB7 RB6 C2 X1 C3 C4 X2 C5 C1 Note: The special event triggers from the CCP1 module will not set interrupt flag bit, TMR1IF (PIR1<0>). © 2007 Microchip Technology Inc. DS39605F-page 107 PIC18F1220/1320 12.7 Using Timer1 as a Real-Time Clock Adding an external LP oscillator to Timer1 (such as the one described in Section 12.2 “Timer1 Oscillator”, above), gives users the option to include RTC functionality to their applications. This is accomplished with an inexpensive watch crystal to provide an accurate time base and several lines of application code to calculate the time. When operating in Sleep mode and using a battery or supercapacitor as a power source, it can completely eliminate the need for a separate RTC device and battery backup. The application code routine, RTCisr, shown in Example 12-1, demonstrates a simple method to increment a counter at one-second intervals using an Interrupt Service Routine. Incrementing the TMR1 register pair to overflow, triggers the interrupt and calls the routine, which increments the seconds counter by one; additional counters for minutes and hours are incremented as the previous counter overflow. Since the register pair is 16 bits wide, counting up to overflow the register directly from a 32.768 kHz clock would take 2 seconds. To force the overflow at the required one-second intervals, it is necessary to preload it; the simplest method is to set the MSb of TMR1H with a BSF instruction. Note that the TMR1L register is never preloaded or altered; doing so may introduce cumulative error over many cycles. For this method to be accurate, Timer1 must operate in Asynchronous mode and the Timer1 overflow interrupt must be enabled (PIE1<0> = 1), as shown in the routine, RTCinit. The Timer1 oscillator must also be enabled and running at all times. EXAMPLE 12-1: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE RTCinit MOVLW 0x80 ; Preload TMR1 register pair MOVWF TMR1H ; for 1 second overflow CLRF TMR1L MOVLW b’00001111’ ; Configure for external clock, MOVWF T1OSC ; Asynchronous operation, external oscillator CLRF secs ; Initialize timekeeping registers CLRF mins ; MOVLW .12 MOVWF hours BSF PIE1, TMR1IE ; Enable Timer1 interrupt RETURN RTCisr BSF TMR1H, 7 ; Preload for 1 sec overflow BCF PIR1, TMR1IF ; Clear interrupt flag INCF secs, F ; Increment seconds MOVLW .59 ; 60 seconds elapsed? CPFSGT secs RETURN ; No, done CLRF secs ; Clear seconds INCF mins, F ; Increment minutes MOVLW .59 ; 60 minutes elapsed? CPFSGT mins RETURN ; No, done CLRF mins ; clear minutes INCF hours, F ; Increment hours MOVLW .23 ; 24 hours elapsed? CPFSGT hours RETURN ; No, done MOVLW .01 ; Reset hours to 1 MOVWF hours RETURN ; DonePIC18F1220/1320 DS39605F-page 108 © 2007 Microchip Technology Inc. TABLE 12-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 u0uu uuuu Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.© 2007 Microchip Technology Inc. DS39605F-page 109 PIC18F1220/1320 13.0 TIMER2 MODULE The Timer2 module timer has the following features: • 8-bit timer (TMR2 register) • 8-bit period register (PR2) • Readable and writable (both registers) • Software programmable prescaler (1:1, 1:4, 1:16) • Software programmable postscaler (1:1 to 1:16) • Interrupt on TMR2 match with PR2 Timer2 has a control register shown in Register 13-1. TMR2 can be shut off by clearing control bit, TMR2ON (T2CON<2>), to minimize power consumption. Figure 13-1 is a simplified block diagram of the Timer2 module. Register 13-1 shows the Timer2 Control register. The prescaler and postscaler selection of Timer2 are controlled by this register. 13.1 Timer2 Operation Timer2 can be used as the PWM time base for the PWM mode of the CCP module. The TMR2 register is readable and writable and is cleared on any device Reset. The input clock (FOSC/4) has a prescale option of 1:1, 1:4 or 1:16, selected by control bits, T2CKPS1:T2CKPS0 (T2CON<1:0>). The match output of TMR2 goes through a 4-bit postscaler (which gives a 1:1 to 1:16 scaling inclusive) to generate a TMR2 interrupt (latched in flag bit, TMR2IF (PIR1<1>)). The prescaler and postscaler counters are cleared when any of the following occurs: • A write to the TMR2 register • A write to the T2CON register • Any device Reset (Power-on Reset, MCLR Reset, Watchdog Timer Reset or Brown-out Reset) TMR2 is not cleared when T2CON is written. REGISTER 13-1: T2CON: TIMER2 CONTROL REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6-3 TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale • • • 1111 = 1:16 Postscale bit 2 TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off bit 1-0 T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 110 © 2007 Microchip Technology Inc. 13.2 Timer2 Interrupt The Timer2 module has an 8-bit period register, PR2. Timer2 increments from 00h until it matches PR2 and then resets to 00h on the next increment cycle. PR2 is a readable and writable register. The PR2 register is initialized to FFh upon Reset. 13.3 Output of TMR2 The output of TMR2 (before the postscaler) is fed to the Synchronous Serial Port module, which optionally uses it to generate the shift clock. FIGURE 13-1: TIMER2 BLOCK DIAGRAM TABLE 13-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER Comparator TMR2 Sets Flag TMR2 Output(1) Reset Postscaler Prescaler PR2 2 FOSC/4 1:1 to 1:16 1:1, 1:4, 1:16 EQ 4 bit TMR2IF TOUTPS3:TOUTPS0 T2CKPS1:T2CKPS0 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 TMR2 Timer2 Module Register 0000 0000 0000 0000 T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 PR2 Timer2 Period Register 1111 1111 1111 1111 Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.© 2007 Microchip Technology Inc. DS39605F-page 111 PIC18F1220/1320 14.0 TIMER3 MODULE The Timer3 module timer/counter has the following features: • 16-bit timer/counter (two 8-bit registers; TMR3H and TMR3L) • Readable and writable (both registers) • Internal or external clock select • Interrupt-on-overflow from FFFFh to 0000h • Reset from CCP module trigger Figure 14-1 is a simplified block diagram of the Timer3 module. Register 14-1 shows the Timer3 Control register. This register controls the operating mode of the Timer3 module and sets the CCP clock source. Register 12-1 shows the Timer1 Control register. This register controls the operating mode of the Timer1 module, as well as contains the Timer1 Oscillator Enable bit (T1OSCEN), which can be a clock source for Timer3. REGISTER 14-1: T3CON: TIMER3 CONTROL REGISTER R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 — T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON bit 7 bit 0 bit 7 RD16: 16-bit Read/Write Mode Enable bit 1 = Enables register read/write of Timer3 in one 16-bit operation 0 = Enables register read/write of Timer3 in two 8-bit operations bit 6 Unimplemented: Read as ‘0’ bit 5-4 T3CKPS1:T3CKPS0: Timer3 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 3 T3CCP1: Timer3 and Timer1 to CCP1 Enable bits 1 = Timer3 is the clock source for compare/capture CCP module 0 = Timer1 is the clock source for compare/capture CCP module bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the system clock comes from Timer1/Timer3.) When TMR3CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR3CS = 0: This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0. bit 1 TMR3CS: Timer3 Clock Source Select bit 1 = External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first falling edge) 0 = Internal clock (FOSC/4) bit 0 TMR3ON: Timer3 On bit 1 = Enables Timer3 0 = Stops Timer3 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 112 © 2007 Microchip Technology Inc. 14.1 Timer3 Operation Timer3 can operate in one of these modes: • As a timer • As a synchronous counter • As an asynchronous counter The operating mode is determined by the clock select bit, TMR3CS (T3CON<1>). When TMR3CS = 0, Timer3 increments every instruction cycle. When TMR3CS = 1, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. When the Timer1 oscillator is enabled (T1OSCEN is set), the RB7/PGD/T1OSI/P1D/KBI3 and RB6/PGC/ T1OSO/T13CKI/P1C/KBI2 pins become inputs. That is, the TRISB7:TRISB6 value is ignored and the pins are read as ‘0’. Timer3 also has an internal “Reset input”. This Reset can be generated by the CCP module (see Section 15.4.4 “Special Event Trigger”). FIGURE 14-1: TIMER3 BLOCK DIAGRAM FIGURE 14-2: TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE TMR3H TMR3L T1OSC T3SYNC TMR3CS T3CKPS1:T3CKPS0 Peripheral Clocks T1OSCEN Enable Oscillator(1) TMR3IF Overflow Interrupt FOSC/4 Internal Clock TMR3ON On/Off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 T1OSO/ T1OSI Flag bit Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. T13CKI CLR CCP Special Event Trigger T3CCPx Timer3 TMR3L T1OSC T3SYNC TMR3CS T3CKPS1:T3CKPS0 Peripheral T1OSCEN Enable Oscillator(1) FOSC/4 Internal Clock TMR3ON On/Off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 T1OSO/ T1OSI TMR3 T13CKI CLR CCP Special Event Trigger T3CCPx To Timer1 Clock Input Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. High Byte Data Bus<7:0> 8 TMR3H 8 8 8 Read TMR3L Write TMR3L Set TMR3IF Flag bit on Overflow Clocks© 2007 Microchip Technology Inc. DS39605F-page 113 PIC18F1220/1320 14.2 Timer1 Oscillator The Timer1 oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN (T1CON<3>) bit. The oscillator is a lowpower oscillator rated for 32 kHz crystals. See Section 12.2 “Timer1 Oscillator” for further details. 14.3 Timer3 Interrupt The TMR3 register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR3 interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR3IF (PIR2<1>). This interrupt can be enabled/disabled by setting/clearing TMR3 Interrupt Enable bit, TMR3IE (PIE2<1>). 14.4 Resetting Timer3 Using a CCP Trigger Output If the CCP module is configured in Compare mode to generate a “special event trigger” (CCP1M3:CCP1M0 = 1011), this signal will reset Timer3. See Section 15.4.4 “Special Event Trigger” for more information. Timer3 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer3 is running in Asynchronous Counter mode, this Reset operation may not work. In the event that a write to Timer3 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPR1H:CCPR1L register pair effectively becomes the period register for Timer3. TABLE 14-1: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER Note: The special event triggers from the CCP module will not set interrupt flag bit, TMR3IF (PIR1<0>). Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR2 OSCFIF — — EEIF — LVDIF TMR3IF — 0--0 -00- 0--0 -00- PIE2 OSCFIE — — EEIE — LVDIE TMR3IE — 0--0 -00- 0--0 -00- IPR2 OSCFIP — — EEIP — LVDIP TMR3IP — 1--1 -11- 1--1 -11- TMR3L Holding Register for the Least Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu TMR3H Holding Register for the Most Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 u0uu uuuu T3CON RD16 — T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0-00 0000 u-uu uuuu Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.PIC18F1220/1320 DS39605F-page 114 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 115 PIC18F1220/1320 15.0 ENHANCED CAPTURE/ COMPARE/PWM (ECCP) MODULE The Enhanced CCP module is implemented as a standard CCP module with Enhanced PWM capabilities. These capabilities allow for 2 or 4 output channels, user-selectable polarity, dead-band control and automatic shutdown and restart and are discussed in detail in Section 15.5 “Enhanced PWM Mode”. The control register for CCP1 is shown in Register 15-1. In addition to the expanded functions of the CCP1CON register, the ECCP module has two additional registers associated with Enhanced PWM operation and auto-shutdown features: • PWM1CON • ECCPAS REGISTER 15-1: CCP1CON REGISTER FOR ENHANCED CCP OPERATION R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 bit 7 bit 0 bit 7-6 P1M1:P1M0: PWM Output Configuration bits If CCP1M<3:2> = 00, 01, 10: xx = P1A assigned as Capture/Compare input; P1B, P1C, P1D assigned as port pins If CCP1M<3:2> = 11: 00 = Single output; P1A modulated; P1B, P1C, P1D assigned as port pins 01 = Full-bridge output forward; P1D modulated; P1A active; P1B, P1C inactive 10 = Half-bridge output; P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins 11 = Full-bridge output reverse; P1B modulated; P1C active; P1A, P1D inactive bit 5-4 DC1B1:DC1B0: PWM Duty Cycle Least Significant bits Capture mode: Unused. Compare mode: Unused. PWM mode: These bits are the two LSbs of the PWM duty cycle. The eight MSbs are found in CCPR1L. bit 3-0 CCP1M3:CCP1M0: ECCP1 Mode Select bits 0000 = Capture/Compare/PWM off (resets ECCP module) 0001 = Unused (reserved) 0010 = Compare mode, toggle output on match (ECCP1IF bit is set) 0011 = Unused (reserved) 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode, set output on match (ECCP1IF bit is set) 1001 = Compare mode, clear output on match (ECCP1IF bit is set) 1010 = Compare mode, generate software interrupt on match (ECCP1IF bit is set, ECCP1 pin returns to port pin operation) 1011 = Compare mode, trigger special event (ECCP1IF bit is set; ECCP resets TMR1 or TMR3 and starts an A/D conversion if the A/D module is enabled) 1100 = PWM mode; P1A, P1C active-high; P1B, P1D active-high 1101 = PWM mode; P1A, P1C active-high; P1B, P1D active-low 1110 = PWM mode; P1A, P1C active-low; P1B, P1D active-high 1111 = PWM mode; P1A, P1C active-low; P1B, P1D active-low Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 116 © 2007 Microchip Technology Inc. 15.1 ECCP Outputs The Enhanced CCP module may have up to four outputs, depending on the selected operating mode. These outputs, designated P1A through P1D, are multiplexed with I/O pins on PORTB. The pin assignments are summarized in Table 15-1. To configure I/O pins as PWM outputs, the proper PWM mode must be selected by setting the P1Mn and CCP1Mn bits (CCP1CON<7:6> and <3:0>, respectively). The appropriate TRISB direction bits for the port pins must also be set as outputs. TABLE 15-1: PIN ASSIGNMENTS FOR VARIOUS ECCP MODES 15.2 CCP Module Capture/Compare/PWM Register 1 (CCPR1) is comprised of two 8-bit registers: CCPR1L (low byte) and CCPR1H (high byte). The CCP1CON register controls the operation of CCP1. All are readable and writable. TABLE 15-2: CCP MODE – TIMER RESOURCE 15.3 Capture Mode In Capture mode, CCPR1H:CCPR1L captures the 16-bit value of the TMR1 or TMR3 registers when an event occurs on pin RB3/CCP1/P1A. An event is defined as one of the following: • every falling edge • every rising edge • every 4th rising edge • every 16th rising edge The event is selected by control bits, CCP1M3:CCP1M0 (CCP1CON<3:0>). When a capture is made, the interrupt request flag bit, CCP1IF (PIR1<2>), is set; it must be cleared in software. If another capture occurs before the value in register CCPR1 is read, the old captured value is overwritten by the new captured value. 15.3.1 CCP PIN CONFIGURATION In Capture mode, the RB3/CCP1/P1A pin should be configured as an input by setting the TRISB<3> bit. 15.3.2 TIMER1/TIMER3 MODE SELECTION The timers that are to be used with the capture feature (either Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation may not work. The timer to be used with the CCP module is selected in the T3CON register. 15.3.3 SOFTWARE INTERRUPT When the Capture mode is changed, a false capture interrupt may be generated. The user should keep bit, CCP1IE (PIE1<2>), clear while changing capture modes to avoid false interrupts and should clear the flag bit, CCP1IF, following any such change in operating mode. ECCP Mode CCP1CON Configuration RB3 RB2 RB6 RB7 Compatible CCP 00xx 11xx CCP1 RB2/INT2 RB6/PGC/T1OSO/T13CKI/KBI2 RB7/PGD/T1OSI/KBI3 Dual PWM 10xx 11xx P1A P1B RB6/PGC/T1OSO/T13CKI/KBI2 RB7/PGD/T1OSI/KBI3 Quad PWM x1xx 11xx P1A P1B P1C P1D Legend: x = Don’t care. Shaded cells indicate pin assignments not used by ECCP in a given mode. Note 1: TRIS register values must be configured appropriately. CCP Mode Timer Resource Capture Compare PWM Timer1 or Timer3 Timer1 or Timer3 Timer2 Note: If the RB3/CCP1/P1A is configured as an output, a write to the port can cause a capture condition. © 2007 Microchip Technology Inc. DS39605F-page 117 PIC18F1220/1320 15.3.4 CCP PRESCALER There are four prescaler settings, specified by bits CCP1M3:CCP1M0. Whenever the CCP module is turned off or the CCP module is not in Capture mode, the prescaler counter is cleared. This means that any Reset will clear the prescaler counter. Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared; therefore, the first capture may be from a non-zero prescaler. Example 15-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the “false” interrupt. EXAMPLE 15-1: CHANGING BETWEEN CAPTURE PRESCALERS FIGURE 15-1: CAPTURE MODE OPERATION BLOCK DIAGRAM 15.4 Compare Mode In Compare mode, the 16-bit CCPR1 register value is constantly compared against either the TMR1 register pair value, or the TMR3 register pair value. When a match occurs, the RB3/CCP1/P1A pin: • Is driven high • Is driven low • Toggles output (high-to-low or low-to-high) • Remains unchanged (interrupt only) The action on the pin is based on the value of control bits, CCP1M3:CCP1M0. At the same time, interrupt flag bit, CCP1IF, is set. 15.4.1 CCP PIN CONFIGURATION The user must configure the RB3/CCP1/P1A pin as an output by clearing the TRISB<3> bit. 15.4.2 TIMER1/TIMER3 MODE SELECTION Timer1 and/or Timer3 must be running in Timer mode or Synchronized Counter mode if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work. 15.4.3 SOFTWARE INTERRUPT MODE When generate software interrupt is chosen, the RB3/ CCP1/P1A pin is not affected. CCP1IF is set and an interrupt is generated (if enabled). 15.4.4 SPECIAL EVENT TRIGGER In this mode, an internal hardware trigger is generated, which may be used to initiate an action. The special event trigger output of CCP1 resets the TMR1 register pair. This allows the CCPR1 register to effectively be a 16-bit programmable period register for Timer1. The special event trigger also sets the GO/DONE bit (ADCON0<1>). This starts a conversion of the currently selected A/D channel if the A/D is on. CLRF CCP1CON ; Turn CCP module off MOVLW NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON MOVWF CCP1CON ; Load CCP1CON with ; this value CCPR1H CCPR1L TMR1H TMR1L Set Flag bit CCP1IF TMR3 Enable Q’s CCP1CON<3:0> CCP1 pin Prescaler ÷ 1, 4, 16 and Edge Detect TMR3H TMR3L TMR1 Enable T3CCP1 T3CCP1 Note: Clearing the CCP1CON register will force the RB3/CCP1/P1A compare output latch to the default low level. This is not the PORTB I/O data latch.PIC18F1220/1320 DS39605F-page 118 © 2007 Microchip Technology Inc. FIGURE 15-2: COMPARE MODE OPERATION BLOCK DIAGRAM TABLE 15-3: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3 CCPR1H CCPR1L TMR1H TMR1L Comparator Q S R Output Logic Special Event Trigger Set Flag bit CCP1IF RB3/CCP1/P1A pin Match TRISB<3> CCP1CON<3:0> Mode Select Output Enable Special Event Trigger will: Reset Timer1 or Timer3, but does not set Timer1 or Timer3 interrupt flag bit and set bit GO/DONE (ADCON0<2>), which starts an A/D conversion. TMR3H TMR3L T3CCP1 0 1 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 TRISB PORTB Data Direction Register 1111 1111 1111 1111 TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 uuuu uuuu CCPR1L Capture/Compare/PWM Register 1 (LSB) xxxx xxxx uuuu uuuu CCPR1H Capture/Compare/PWM Register 1 (MSB) xxxx xxxx uuuu uuuu CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 0000 0000 TMR3L Holding Register for the Least Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu TMR3H Holding Register for the Most Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu T3CON RD16 — T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0-00 0000 u-uu uuuu ADCON0 VCFG1 VCFG0 — CHS2 CHS1 CHS0 GO/DONE ADON 00-0 0000 00-0 0000 Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by Capture and Timer1.© 2007 Microchip Technology Inc. DS39605F-page 119 PIC18F1220/1320 15.5 Enhanced PWM Mode The Enhanced PWM Mode provides additional PWM output options for a broader range of control applications. The module is an upwardly compatible version of the standard CCP module and offers up to four outputs, designated P1A through P1D. Users are also able to select the polarity of the signal (either active-high or active-low). The module’s output mode and polarity are configured by setting the P1M1:P1M0 and CCP1M3CCP1M0 bits of the CCP1CON register (CCP1CON<7:6> and CCP1CON<3:0>, respectively). Figure 15-3 shows a simplified block diagram of PWM operation. All control registers are double-buffered and are loaded at the beginning of a new PWM cycle (the period boundary when Timer2 resets) in order to prevent glitches on any of the outputs. The exception is the PWM Delay register, ECCP1DEL, which is loaded at either the duty cycle boundary or the boundary period (whichever comes first). Because of the buffering, the module waits until the assigned timer resets instead of starting immediately. This means that Enhanced PWM waveforms do not exactly match the standard PWM waveforms, but are instead offset by one full instruction cycle (4 TOSC). As before, the user must manually configure the appropriate TRIS bits for output. 15.5.1 PWM PERIOD The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the equation: EQUATION 15-1: PWM PERIOD PWM frequency is defined as 1/[PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: • TMR2 is cleared • The CCP1 pin is set (if PWM duty cycle = 0%, the CCP1 pin will not be set) • The PWM duty cycle is copied from CCPR1L into CCPR1H 15.5.2 PWM DUTY CYCLE The PWM duty cycle is specified by writing to the CCPR1L register and to the CCP1CON<5:4> bits. Up to 10-bit resolution is available. The CCPR1L contains the eight MSbs and the CCP1CON<5:4> contains the two LSbs. This 10-bit value is represented by CCPR1L:CCP1CON<5:4>. The PWM duty cycle is calculated by the equation: EQUATION 15-2: PWM DUTY CYCLE CCPR1L and CCP1CON<5:4> can be written to at any time, but the duty cycle value is not copied into CCPR1H until a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR1H is a read-only register. The CCPR1H register and a 2-bit internal latch are used to double-buffer the PWM duty cycle. This double-buffering is essential for glitchless PWM operation. When the CCPR1H and 2-bit latch match TMR2, concatenated with an internal 2-bit Q clock or two bits of the TMR2 prescaler, the CCP1 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the equation: EQUATION 15-3: PWM RESOLUTION 15.5.3 PWM OUTPUT CONFIGURATIONS The P1M1:P1M0 bits in the CCP1CON register allow one of four configurations: • Single Output • Half-Bridge Output • Full-Bridge Output, Forward mode • Full-Bridge Output, Reverse mode The Single Output mode is the Standard PWM mode discussed in Section 15.5 “Enhanced PWM Mode”. The Half-Bridge and Full-Bridge Output modes are covered in detail in the sections that follow. The general relationship of the outputs in all configurations is summarized in Figure 15-4. TABLE 15-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz Note: The Timer2 postscaler (see Section 13.0 “Timer2 Module”) is not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output. PWM Period = [(PR2) + 1] • 4 • TOSC • (TMR2 Prescale Value) Note: If the PWM duty cycle value is longer than the PWM period, the CCP1 pin will not be cleared. PWM Duty Cycle = (CCPR1L:CCP1CON<5:4>) • TOSC • (TMR2 Prescale Value) ( ) PWM Resolution (max) = FOSC FPWM log log(2) bits PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz Timer Prescaler (1, 4, 16) 16 4 1 1 1 1 PR2 Value FFh FFh FFh 3Fh 1Fh 17h Maximum Resolution (bits) 10 10 10 8 7 6.58PIC18F1220/1320 DS39605F-page 120 © 2007 Microchip Technology Inc. FIGURE 15-3: SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODULE FIGURE 15-4: PWM OUTPUT RELATIONSHIPS (ACTIVE-HIGH STATE) CCPR1L CCPR1H (Slave) Comparator TMR2 Comparator PR2 (Note 1) R Q S Duty Cycle Registers CCP1CON<5:4> Clear Timer, set CCP1 pin and latch D.C. Note: The 8-bit TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler to create the 10-bit time base. TRISB<3> RB3/CCP1/P1A TRISB<2> RB2/P1B/INT2 TRISB<6> RB6/PGC/T1OSO/T13CKI/ TRISB<7> RB7/PGD/T1OSI/P1D/KBI3 Output Controller P1M1<1:0> 2 CCP1M<3:0> 4 CCP1DEL CCP1/P1A P1B P1C P1D P1C/KBI2 0 Period 00 10 01 11 SIGNAL PR2+1 CCP1CON<7:6> P1A Modulated P1A Modulated P1B Modulated P1A Active P1B Inactive P1C Inactive P1D Modulated P1A Inactive P1B Modulated P1C Active P1D Inactive Duty Cycle (Single Output) (Half-Bridge) (Full-Bridge, Forward) (Full-Bridge, Reverse) Delay(1) Delay(1)© 2007 Microchip Technology Inc. DS39605F-page 121 PIC18F1220/1320 FIGURE 15-5: PWM OUTPUT RELATIONSHIPS (ACTIVE-LOW STATE) 0 Period 00 10 01 11 SIGNAL PR2+1 CCP1CON<7:6> P1A Modulated P1A Modulated P1B Modulated P1A Active P1B Inactive P1C Inactive P1D Modulated P1A Inactive P1B Modulated P1C Active P1D Inactive Duty Cycle (Single Output) (Half-Bridge) (Full-Bridge, Forward) (Full-Bridge, Reverse) Delay(1) Delay(1) Relationships: • Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value) • Duty Cycle = TOSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value) • Delay = 4 * TOSC * (PWM1CON<6:0>) Note 1: Dead-band delay is programmed using the PWM1CON register (Section 15.5.6 “Programmable Dead-Band Delay”).PIC18F1220/1320 DS39605F-page 122 © 2007 Microchip Technology Inc. 15.5.4 HALF-BRIDGE MODE In the Half-Bridge Output mode, two pins are used as outputs to drive push-pull loads. The PWM output signal is output on the RB3/CCP1/P1A pin, while the complementary PWM output signal is output on the RB2/P1B/INT2 pin (Figure 15-6). This mode can be used for half-bridge applications, as shown in Figure 15-7, or for full-bridge applications, where four power switches are being modulated with two PWM signals. In Half-Bridge Output mode, the programmable deadband delay can be used to prevent shoot-through current in half-bridge power devices. The value of bits, PDC6:PDC0 (PWM1CON<6:0>), sets the number of instruction cycles before the output is driven active. If the value is greater than the duty cycle, the corresponding output remains inactive during the entire cycle. See Section 15.5.6 “Programmable Dead-Band Delay” for more details of the dead-band delay operations. The TRISB<3> and TRISB<2> bits must be cleared to configure P1A and P1B as outputs. FIGURE 15-6: HALF-BRIDGE PWM OUTPUT (ACTIVE-HIGH) FIGURE 15-7: EXAMPLES OF HALF-BRIDGE OUTPUT MODE APPLICATIONS Period Duty Cycle td td (1) P1A P1B td = Dead-Band Delay Period (1) (1) Note 1: At this time, the TMR2 register is equal to the PR2 register. PIC18F1220/1320 P1A P1B FET Driver FET Driver Load + V - + V - FET Driver FET Driver V+ V- Load FET Driver FET Driver PIC18F1220/1320 P1A P1B Standard Half-Bridge Circuit (“Push-Pull”) Half-Bridge Output Driving a Full-Bridge Circuit© 2007 Microchip Technology Inc. DS39605F-page 123 PIC18F1220/1320 15.5.5 FULL-BRIDGE MODE In Full-Bridge Output mode, four pins are used as outputs; however, only two outputs are active at a time. In the Forward mode, pin RB3/CCP1/P1A is continuously active and pin RB7/PGD/T1OSI/P1D/KBI3 is modulated. In the Reverse mode, pin RB6/PGC/ T1OSO/T13CKI/P1C/KBI2 is continuously active and pin RB2/P1B/INT2 is modulated. These are illustrated in Figure 15-8. The TRISB<3:2> and TRISB<7:6> bits must be cleared to make the P1A, P1B, P1C and P1D pins output. FIGURE 15-8: FULL-BRIDGE PWM OUTPUT (ACTIVE-HIGH) Period Duty Cycle P1A P1B P1C P1D Forward Mode (1) Period Duty Cycle P1A P1C P1D P1B Reverse Mode (1) (1) (1) Note 1: At this time, the TMR2 register is equal to the PR2 register.PIC18F1220/1320 DS39605F-page 124 © 2007 Microchip Technology Inc. FIGURE 15-9: EXAMPLE OF FULL-BRIDGE APPLICATION 15.5.5.1 Direction Change in Full-Bridge Mode In the Full-Bridge Output mode, the P1M1 bit in the CCP1CON register allows the user to control the Forward/Reverse direction. When the application firmware changes this direction control bit, the module will assume the new direction on the next PWM cycle. Just before the end of the current PWM period, the modulated outputs (P1B and P1D) are placed in their inactive state, while the unmodulated outputs (P1A and P1C) are switched to drive in the opposite direction. This occurs in a time interval of (4 TOSC * (Timer2 Prescale Value) before the next PWM period begins. The Timer2 prescaler will be either 1,4 or 16, depending on the value of the T2CKPS bit (T2CON<1:0>). During the interval from the switch of the unmodulated outputs to the beginning of the next period, the modulated outputs (P1B and P1D) remain inactive. This relationship is shown in Figure 15-10. Note that in the Full-Bridge Output mode, the ECCP module does not provide any dead-band delay. In general, since only one output is modulated at all times, dead-band delay is not required. However, there is a situation where a dead-band delay might be required. This situation occurs when both of the following conditions are true: 1. The direction of the PWM output changes when the duty cycle of the output is at or near 100%. 2. The turn-off time of the power switch, including the power device and driver circuit, is greater than the turn-on time. Figure 15-11 shows an example where the PWM direction changes from forward to reverse, at a near 100% duty cycle. At time t1, the output P1A and P1D become inactive, while output P1C becomes active. In this example, since the turn-off time of the power devices is longer than the turn-on time, a shoot-through current may flow through power devices QC and QD (see Figure 15-9) for the duration of ‘t’. The same phenomenon will occur to power devices QA and QB for PWM direction change from reverse to forward. If changing PWM direction at high duty cycle is required for an application, one of the following requirements must be met: 1. Reduce PWM for a PWM period before changing directions. 2. Use switch drivers that can drive the switches off faster than they can drive them on. Other options to prevent shoot-through current may exist. PIC18F1220/1320 P1A P1C FET Driver FET Driver V+ V- Load FET Driver FET Driver P1B P1D QA QB QD QC© 2007 Microchip Technology Inc. DS39605F-page 125 PIC18F1220/1320 FIGURE 15-10: PWM DIRECTION CHANGE (ACTIVE-HIGH) FIGURE 15-11: PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE (ACTIVE-HIGH) DC PWM Period(1) SIGNAL Note 1: The direction bit in the CCP1 Control register (CCP1CON<7>) is written any time during the PWM cycle. 2: When changing directions, the P1A and P1C toggle one Timer2 count before the end of the current PWM cycle. The modulated P1B and P1D signals are inactive at this time. PWM Period One Timer2 Count(2) P1A P1B P1C P1D DC Forward Period Reverse Period P1A tON tOFF t = tOFF – tON P1B P1C P1D External Switch D Potential Shoot-Through Current Note 1: tON is the turn-on delay of power switch QC and its driver. 2: tOFF is the turn-off delay of power switch QD and its driver. External Switch C t1 DC DCPIC18F1220/1320 DS39605F-page 126 © 2007 Microchip Technology Inc. 15.5.6 PROGRAMMABLE DEAD-BAND DELAY In half-bridge applications where all power switches are modulated at the PWM frequency at all times, the power switches normally require more time to turn off than to turn on. If both the upper and lower power switches are switched at the same time (one turned on and the other turned off), both switches may be on for a short period of time until one switch completely turns off. During this brief interval, a very high current (shootthrough current) may flow through both power switches, shorting the bridge supply. To avoid this potentially destructive shoot-through current from flowing during switching, turning on either of the power switches is normally delayed to allow the other switch to completely turn off. In the Half-Bridge Output mode, a digitally programmable dead-band delay is available to avoid shoot-through current from destroying the bridge power switches. The delay occurs at the signal transition from the non-active state to the active state. See Figure 15-6 for an illustration. The lower seven bits of the PWM1CON register (Register 15-2) sets the delay period in terms of microcontroller instruction cycles (TCY or 4 TOSC). 15.5.7 ENHANCED PWM AUTO-SHUTDOWN When the ECCP is programmed for any of the Enhanced PWM modes, the active output pins may be configured for auto-shutdown. Auto-shutdown immediately places the Enhanced PWM output pins into a defined shutdown state when a shutdown event occurs. A shutdown event can be caused by the INT0, INT1 or INT2 pins (or any combination of these three sources). The auto-shutdown feature can be disabled by not selecting any auto-shutdown sources. The autoshutdown sources to be used are selected using the ECCPAS2:ECCPAS0 bits (bits <6:4> of the ECCPAS register). When a shutdown occurs, the output pins are asynchronously placed in their shutdown states, specified by the PSSAC1:PSSAC0 and PSSBD1:PSSBD0 bits (ECCPAS<3:0>). Each pin pair (P1A/P1C and P1B/P1D) may be set to drive high, drive low or be tristated (not driving). The ECCPASE bit (ECCPAS<7>) is also set to hold the Enhanced PWM outputs in their shutdown states. The ECCPASE bit is set by hardware when a shutdown event occurs. If automatic restarts are not enabled, the ECCPASE bit is cleared by firmware when the cause of the shutdown clears. If automatic restarts are enabled, the ECCPASE bit is automatically cleared when the cause of the auto-shutdown has cleared. If the ECCPASE bit is set when a PWM period begins, the PWM outputs remain in their shutdown state for that entire PWM period. When the ECCPASE bit is cleared, the PWM outputs will return to normal operation at the beginning of the next PWM period. REGISTER 15-2: PWM1CON: PWM CONFIGURATION REGISTER Note: Writing to the ECCPASE bit is disabled while a shutdown condition is active. R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 PRSEN PDC6 PDC5 PDC4 PDC3 PDC2 PDC1 PDC0 bit 7 bit 0 bit 7 PRSEN: PWM Restart Enable bit 1 = Upon auto-shutdown, the ECCPASE bit clears automatically once the shutdown event goes away; the PWM restarts automatically 0 = Upon auto-shutdown, ECCPASE must be cleared in software to restart the PWM bit 6-0 PDC<6:0>: PWM Delay Count bits Number of FOSC/4 (4 * TOSC) cycles between the scheduled time when a PWM signal should transition active and the actual time it transitions active. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 127 PIC18F1220/1320 REGISTER 15-3: ECCPAS: ENHANCED CAPTURE/COMPARE/PWM/AUTO-SHUTDOWN CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 bit 7 bit 0 bit 7 ECCPASE: ECCP Auto-Shutdown Event Status bit 0 = ECCP outputs are operating 1 = A shutdown event has occurred; ECCP outputs are in shutdown state bit 6 ECCPAS2: ECCP Auto-Shutdown bit 2 0 = INT0 pin has no effect 1 = INT0 pin low causes shutdown bit 5 ECCPAS1: ECCP Auto-Shutdown bit 1 0 = INT2 pin has no effect 1 = INT2 pin low causes shutdown bit 4 ECCPAS0: ECCP Auto-Shutdown bit 0 0 = INT1 pin has no effect 1 = INT1 pin low causes shutdown bit 3-2 PSSACn: Pins A and C Shutdown State Control bits 00 = Drive Pins A and C to ‘0’ 01 = Drive Pins A and C to ‘1’ 1x = Pins A and C tri-state bit 1-0 PSSBDn: Pins B and D Shutdown State Control bits 00 = Drive Pins B and D to ‘0’ 01 = Drive Pins B and D to ‘1’ 1x = Pins B and D tri-state Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 128 © 2007 Microchip Technology Inc. 15.5.7.1 Auto-Shutdown and Automatic Restart The auto-shutdown feature can be configured to allow automatic restarts of the module, following a shutdown event. This is enabled by setting the PRSEN bit of the PWM1CON register (PWM1CON<7>). In Shutdown mode with PRSEN = 1 (Figure 15-12), the ECCPASE bit will remain set for as long as the cause of the shutdown continues. When the shutdown condition clears, the ECCPASE bit is automatically cleared. If PRSEN = 0 (Figure 15-13), once a shutdown condition occurs, the ECCPASE bit will remain set until it is cleared by firmware. Once ECCPASE is cleared, the Enhanced PWM will resume at the beginning of the next PWM period. Independent of the PRSEN bit setting, the ECCPASE bit cannot be cleared as long as the cause of the shutdown persists. The Auto-Shutdown mode can be forced by writing a ‘1’ to the ECCPASE bit. 15.5.8 START-UP CONSIDERATIONS When the ECCP module is used in the PWM mode, the application hardware must use the proper external pullup and/or pull-down resistors on the PWM output pins. When the microcontroller is released from Reset, all of the I/O pins are in the high-impedance state. The external circuits must keep the power switch devices in the off state, until the microcontroller drives the I/O pins with the proper signal levels, or activates the PWM output(s). The CCP1M1:CCP1M0 bits (CCP1CON<1:0>) allow the user to choose whether the PWM output signals are active-high or active-low for each pair of PWM output pins (P1A/P1C and P1B/P1D). The PWM output polarities must be selected before the PWM pins are configured as outputs. Changing the polarity configuration while the PWM pins are configured as outputs is not recommended, since it may result in damage to the application circuits. The P1A, P1B, P1C and P1D output latches may not be in the proper states when the PWM module is initialized. Enabling the PWM pins for output at the same time as the ECCP module may cause damage to the application circuit. The ECCP module must be enabled in the proper output mode and complete a full PWM cycle, before configuring the PWM pins as outputs. The completion of a full PWM cycle is indicated by the TMR2IF bit being set as the second PWM period begins. FIGURE 15-12: PWM AUTO-SHUTDOWN (PRSEN = 1, AUTO-RESTART ENABLED) FIGURE 15-13: PWM AUTO-SHUTDOWN (PRSEN = 0, AUTO-RESTART DISABLED) Note: Writing to the ECCPASE bit is disabled while a shutdown condition is active. Shutdown PWM ECCPASE bit Activity Event PWM Period PWM Period PWM Period Duty Cycle Dead Time Duty Cycle Duty Cycle Dead Time Dead Time Shutdown PWM ECCPASE bit Activity Event PWM Period PWM Period PWM Period ECCPASE Cleared by Firmware Duty Cycle Dead Time Duty Cycle Duty Cycle Dead Time Dead Time© 2007 Microchip Technology Inc. DS39605F-page 129 PIC18F1220/1320 15.5.9 SETUP FOR PWM OPERATION The following steps should be taken when configuring the ECCP1 module for PWM operation: 1. Configure the PWM pins P1A and P1B (and P1C and P1D, if used) as inputs by setting the corresponding TRISB bits. 2. Set the PWM period by loading the PR2 register. 3. Configure the ECCP module for the desired PWM mode and configuration by loading the CCP1CON register with the appropriate values: • Select one of the available output configurations and direction with the P1M1:P1M0 bits. • Select the polarities of the PWM output signals with the CCP1M3:CCP1M0 bits. 4. Set the PWM duty cycle by loading the CCPR1L register and CCP1CON<5:4> bits. 5. For Half-Bridge Output mode, set the deadband delay by loading PWM1CON<6:0> with the appropriate value. 6. If auto-shutdown operation is required, load the ECCPAS register: • Select the auto-shutdown sources using the ECCPAS<2:0> bits. • Select the shutdown states of the PWM output pins using PSSAC1:PSSAC0 and PSSBD1:PSSBD0 bits. • Set the ECCPASE bit (ECCPAS<7>). 7. If auto-restart operation is required, set the PRSEN bit (PWM1CON<7>). 8. Configure and start TMR2: • Clear the TMR2 interrupt flag bit by clearing the TMR2IF bit (PIR1<1>). • Set the TMR2 prescale value by loading the T2CKPS bits (T2CON<1:0>). • Enable Timer2 by setting the TMR2ON bit (T2CON<2>). 9. Enable PWM outputs after a new PWM cycle has started: • Wait until TMR2 overflows (TMR2IF bit is set). • Enable the CCP1/P1A, P1B, P1C and/or P1D pin outputs by clearing the respective TRISB bits. • Clear the ECCPASE bit (ECCPAS<7>). 15.5.10 OPERATION IN LOW-POWER MODES In the Low-Power Sleep mode, all clock sources are disabled. Timer2 will not increment and the state of the module will not change. If the ECCP pin is driving a value, it will continue to drive that value. When the device wakes up, it will continue from this state. If TwoSpeed Start-ups are enabled, the initial start-up frequency may not be stable if the INTOSC is being used. In PRI_IDLE mode, the primary clock will continue to clock the ECCP module without change. In all other low-power modes, the selected low-power mode clock will clock Timer2. Other low-power mode clocks will most likely be different than the primary clock frequency. 15.5.10.1 Operation with Fail-Safe Clock Monitor If the Fail-Safe Clock Monitor is enabled (CONFIG1H<6> is programmed), a clock failure will force the device into the Low-Power RC_RUN mode and the OSCFIF bit (PIR2<7>) will be set. The ECCP will then be clocked from the INTRC clock source, which may have a different clock frequency than the primary clock. By loading the IRCF2:IRCF0 bits on Resets, the user can enable the INTOSC at a high clock speed in the event of a clock failure. See the previous section for additional details. 15.5.11 EFFECTS OF A RESET Both power-on and subsequent Resets will force all ports to input mode and the CCP registers to their Reset states. This forces the Enhanced CCP module to reset to a state compatible with the standard CCP module.PIC18F1220/1320 DS39605F-page 130 © 2007 Microchip Technology Inc. TABLE 15-5: REGISTERS ASSOCIATED WITH ENHANCED PWM AND TIMER2 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u RCON IPEN — — RI TO PD POR BOR 0--1 11qq 0--q qquu PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 TMR2 Timer2 Module Register 0000 0000 0000 0000 PR2 Timer2 Module Period Register 1111 1111 1111 1111 T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 TRISB PORTB Data Direction Register 1111 1111 1111 1111 CCPR1H Enhanced Capture/Compare/PWM Register 1 High Byte xxxx xxxx uuuu uuuu CCPR1L Enhanced Capture/Compare/PWM Register 1 Low Byte xxxx xxxx uuuu uuuu CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 0000 0000 ECCPAS ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 0000 0000 0000 0000 PWM1CON PRSEN PDC6 PDC5 PDC4 PDC3 PDC2 PDC1 PDC0 0000 0000 uuuu uuuu OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 0000 qq00 0000 qq00 Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by the ECCP module in Enhanced PWM mode.© 2007 Microchip Technology Inc. DS39605F-page 131 PIC18F1220/1320 16.0 ENHANCED ADDRESSABLE UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (EUSART) The Enhanced Addressable Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module can be configured as a full-duplex asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers. It can also be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. The Enhanced Addressable USART module implements additional features, including automatic baud rate detection and calibration, automatic wake-up on Sync Break reception and 12-bit Break character transmit. These features make it ideally suited for use in Local Interconnect Network (LIN) bus systems. The EUSART can be configured in the following modes: • Asynchronous (full duplex) with: - Auto-wake-up on character reception - Auto-baud calibration - 12-bit Break character transmission • Synchronous – Master (half duplex) with selectable clock polarity • Synchronous – Slave (half duplex) with selectable clock polarity The RB1/AN5/TX/CK/INT1 and RB4/AN6/RX/DT/KBI0 pins must be configured as follows for use with the Universal Synchronous Asynchronous Receiver Transmitter: • SPEN (RCSTA<7>) bit must be set ( = 1), • PCFG6:PCFG5 (ADCON1<5:6>) must be set ( = 1), • TRISB<4> bit must be set ( = 1) and • TRISB<1> bit must be set ( = 1). The operation of the Enhanced USART module is controlled through three registers: • Transmit Status and Control (TXSTA) • Receive Status and Control (RCSTA) • Baud Rate Control (BAUDCTL) These are detailed in on the following pages in Register 16-1, Register 16-2 and Register 16-3, respectively. 16.1 Asynchronous Operation in Power Managed Modes The EUSART may operate in Asynchronous mode while the peripheral clocks are being provided by the internal oscillator block. This makes it possible to remove the crystal or resonator that is commonly connected as the primary clock on the OSC1 and OSC2 pins. The factory calibrates the internal oscillator block output (INTOSC) for 8 MHz (see Table 22-6). However, this frequency may drift as VDD or temperature changes and this directly affects the asynchronous baud rate. Two methods may be used to adjust the baud rate clock, but both require a reference clock source of some kind. The first (preferred) method uses the OSCTUNE register to adjust the INTOSC output back to 8 MHz. Adjusting the value in the OSCTUNE register allows for fine resolution changes to the system clock source (see Section 3.6 “INTOSC Frequency Drift” for more information). The other method adjusts the value in the Baud Rate Generator (BRG). There may not be fine enough resolution when adjusting the Baud Rate Generator to compensate for a gradual change in the peripheral clock frequency. Note: The EUSART control will automatically reconfigure the pin from input to output as needed.PIC18F1220/1320 DS39605F-page 132 © 2007 Microchip Technology Inc. REGISTER 16-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D bit 7 bit 0 bit 7 CSRC: Clock Source Select bit Asynchronous mode: Don’t care. Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) bit 6 TX9: 9-bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission bit 5 TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled Note: SREN/CREN overrides TXEN in Sync mode. bit 4 SYNC: EUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 SENDB: Send Break Character bit Asynchronous mode: 1 = Send Sync Break on next transmission (cleared by hardware upon completion) 0 = Sync Break transmission completed Synchronous mode: Don’t care. bit 2 BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode. bit 1 TRMT: Transmit Shift Register Status bit 1 = TSR Idle 0 = TSR busy bit 0 TX9D: 9th bit of Transmit Data Can be address/data bit or a parity bit. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 133 PIC18F1220/1320 REGISTER 16-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x SPEN RX9 SREN CREN ADDEN FERR OERR RX9D bit 7 bit 0 bit 7 SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins) 0 = Serial port disabled (held in Reset) bit 6 RX9: 9-bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5 SREN: Single Receive Enable bit Asynchronous mode: Don’t care. Synchronous mode – Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode – Slave: Don’t care. bit 4 CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN) 0 = Disables continuous receive bit 3 ADDEN: Address Detect Enable bit Asynchronous mode 9-bit (RX9 = 1): 1 = Enables address detection, generates RCIF interrupt and loads RCREG when RX9D is set 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit Asynchronous mode 8-bit (RX9 = 0): Don’t care. bit 2 FERR: Framing Error bit 1 = Framing error (can be updated by reading RCREG register and receiving next valid byte) 0 = No framing error bit 1 OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit CREN) 0 = No overrun error bit 0 RX9D: 9th bit of Received Data This can be address/data bit or a parity bit and must be calculated by user firmware. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 134 © 2007 Microchip Technology Inc. REGISTER 16-3: BAUDCTL: BAUD RATE CONTROL REGISTER U-0 R-1 U-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 — RCIDL — SCKP BRG16 — WUE ABDEN bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 RCIDL: Receive Operation Idle Status bit 1 = Receiver is Idle 0 = Receiver is busy bit 5 Unimplemented: Read as ‘0’ bit 4 SCKP: Synchronous Clock Polarity Select bit Asynchronous mode: Unused in this mode. Synchronous mode: 1 = Idle state for clock (CK) is a high level 0 = Idle state for clock (CK) is a low level bit 3 BRG16: 16-bit Baud Rate Register Enable bit 1 = 16-bit Baud Rate Generator – SPBRGH and SPBRG 0 = 8-bit Baud Rate Generator – SPBRG only (Compatible mode), SPBRGH value ignored bit 2 Unimplemented: Read as ‘0’ bit 1 WUE: Wake-up Enable bit Asynchronous mode: 1 = EUSART will continue to sample the RX pin – interrupt generated on falling edge; bit cleared in hardware on following rising edge 0 = RX pin not monitored or rising edge detected Synchronous mode: Unused in this mode. bit 0 ABDEN: Auto-Baud Detect Enable bit Asynchronous mode: 1 = Enable baud rate measurement on the next character – requires reception of a Sync byte (55h); cleared in hardware upon completion 0 = Baud rate measurement disabled or completed Synchronous mode: Unused in this mode. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 135 PIC18F1220/1320 16.2 EUSART Baud Rate Generator (BRG) The BRG is a dedicated 8-bit or 16-bit generator, that supports both the Asynchronous and Synchronous modes of the EUSART. By default, the BRG operates in 8-bit mode; setting the BRG16 bit (BAUDCTL<3>) selects 16-bit mode. The SPBRGH:SPBRG register pair controls the period of a free running timer. In Asynchronous mode, bits BRGH (TXSTA<2>) and BRG16 also control the baud rate. In Synchronous mode, bit BRGH is ignored. Table 16-1 shows the formula for computation of the baud rate for different EUSART modes which only apply in Master mode (internally generated clock). Given the desired baud rate and FOSC, the nearest integer value for the SPBRGH:SPBRG registers can be calculated using the formulas in Table 16-1. From this, the error in baud rate can be determined. An example calculation is shown in Example 16-1. Typical baud rates and error values for the various asynchronous modes are shown in Table 16-2. It may be advantageous to use the high baud rate (BRGH = 1), or the 16-bit BRG to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. Writing a new value to the SPBRGH:SPBRG registers causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate. 16.2.1 POWER MANAGED MODE OPERATION The system clock is used to generate the desired baud rate; however, when a power managed mode is entered, the clock source may be operating at a different frequency than in PRI_RUN mode. In Sleep mode, no clocks are present and in PRI_IDLE mode, the primary clock source continues to provide clocks to the Baud Rate Generator; however, in other power managed modes, the clock frequency will probably change. This may require the value in SPBRG to be adjusted. If the system clock is changed during an active receive operation, a receive error or data loss may result. To avoid this problem, check the status of the RCIDL bit and make sure that the receive operation is Idle before changing the system clock. 16.2.2 SAMPLING The data on the RB4/AN6/RX/DT/KBI0 pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX pin. TABLE 16-1: BAUD RATE FORMULAS EXAMPLE 16-1: CALCULATING BAUD RATE ERROR Configuration Bits BRG/EUSART Mode Baud Rate Formula SYNC BRG16 BRGH 000 8-bit/Asynchronous FOSC/[64 (n + 1)] 001 8-bit/Asynchronous FOSC/[16 (n + 1)] 010 16-bit/Asynchronous 011 16-bit/Asynchronous 10x 8-bit/Synchronous FOSC/[4 (n + 1)] 11x 16-bit/Synchronous Legend: x = Don’t care, n = value of SPBRGH:SPBRG register pair For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG: Desired Baud Rate = FOSC/(64 ([SPBRGH:SPBRG] + 1)) Solving for SPBRGH:SPBRG: X = ((FOSC/Desired Baud Rate)/64) – 1 = ((16000000/9600)/64) – 1 = [25.042] = 25 Calculated Baud Rate= 16000000/(64 (25 + 1)) = 9615 Error = (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate = (9615 – 9600)/9600 = 0.16%PIC18F1220/1320 DS39605F-page 136 © 2007 Microchip Technology Inc. TABLE 16-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 -010 0000 -010 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented, read as ‘0’. Shaded cells are not used by the BRG. TABLE 16-3: BAUD RATES FOR ASYNCHRONOUS MODES BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 0 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 — — — — — — — — — — — — 1.2 — — — 1.221 1.73 255 1.202 0.16 129 1201 -0.16 103 2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2403 -0.16 51 9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9615 -0.16 12 19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7 — — — 57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2 — — — 115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1 — — — BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 0 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 0.300 0.16 207 300 -0.16 103 300 -0.16 51 1.2 1.202 0.16 51 1201 -0.16 25 1201 -0.16 12 2.4 2.404 0.16 25 2403 -0.16 12 — — — 9.6 8.929 -6.99 6 — — — — — — 19.2 20.833 8.51 2 — — — — — — 57.6 62.500 8.51 0 — — — — — — 115.2 62.500 -45.75 0 — — — — — —© 2007 Microchip Technology Inc. DS39605F-page 137 PIC18F1220/1320 BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 0 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 2.4 — — — — — — 2.441 1.73 255 2403 -0.16 207 9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 — — — BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 0 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 — — — — — — 300 -0.16 207 1.2 1.202 0.16 207 1201 -0.16 103 1201 -0.16 51 2.4 2.404 0.16 103 2403 -0.16 51 2403 -0.16 25 9.6 9.615 0.16 25 9615 -0.16 12 — — — 19.2 19.231 0.16 12 — — — — — — 57.6 62.500 8.51 3 — — — — — — 115.2 125.000 8.51 1 — — — — — — BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 1 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 300 -0.04 1665 1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1201 -0.16 415 2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2403 -0.16 207 9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 — — — BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 1 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 0.300 0.04 832 300 -0.16 415 300 -0.16 207 1.2 1.202 0.16 207 1201 -0.16 103 1201 -0.16 51 2.4 2.404 0.16 103 2403 -0.16 51 2403 -0.16 25 9.6 9.615 0.16 25 9615 -0.16 12 — — — 19.2 19.231 0.16 12 — — — — — — 57.6 62.500 8.51 3 — — — — — — 115.2 125.000 8.51 1 — — — — — — TABLE 16-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)PIC18F1220/1320 DS39605F-page 138 © 2007 Microchip Technology Inc. BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 0.300 0.00 33332 0.300 0.00 16665 0.300 0.00 8332 300 -0.01 6665 1.2 1.200 0.00 8332 1.200 0.02 4165 1.200 0.02 2082 1200 -0.04 1665 2.4 2.400 0.02 4165 2.400 0.02 2082 2.402 0.06 1040 2400 -0.04 832 9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9615 -0.16 207 19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19230 -0.16 103 57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57142 0.79 34 115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117647 -2.12 16 BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) 0.3 0.300 0.01 3332 300 -0.04 1665 300 -0.04 832 1.2 1.200 0.04 832 1201 -0.16 415 1201 -0.16 207 2.4 2.404 0.16 415 2403 -0.16 207 2403 -0.16 103 9.6 9.615 0.16 103 9615 -0.16 51 9615 -0.16 25 19.2 19.231 0.16 51 19230 -0.16 25 19230 -0.16 12 57.6 58.824 2.12 16 55555 3.55 8 — — — 115.2 111.111 -3.55 8 — — — — — — TABLE 16-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)© 2007 Microchip Technology Inc. DS39605F-page 139 PIC18F1220/1320 16.2.3 AUTO-BAUD RATE DETECT The Enhanced USART module supports the automatic detection and calibration of baud rate. This feature is active only in Asynchronous mode and while the WUE bit is clear. The automatic baud rate measurement sequence (Figure 16-1) begins whenever a Start bit is received and the ABDEN bit is set. The calculation is self-averaging. In the Auto-Baud Rate Detect (ABD) mode, the clock to the BRG is reversed. Rather than the BRG clocking the incoming RX signal, the RX signal is timing the BRG. In ABD mode, the internal Baud Rate Generator is used as a counter to time the bit period of the incoming serial byte stream. Once the ABDEN bit is set, the state machine will clear the BRG and look for a Start bit. The Auto-Baud Detect must receive a byte with the value 55h (ASCII “U”, which is also the LIN bus Sync character), in order to calculate the proper bit rate. The measurement is taken over both a low and a high bit time in order to minimize any effects caused by asymmetry of the incoming signal. After a Start bit, the SPBRG begins counting up using the preselected clock source on the first rising edge of RX. After eight bits on the RX pin, or the fifth rising edge, an accumulated value totalling the proper BRG period is left in the SPBRGH:SPBRG registers. Once the 5th edge is seen (should correspond to the Stop bit), the ABDEN bit is automatically cleared. While calibrating the baud rate period, the BRG registers are clocked at 1/8th the preconfigured clock rate. Note that the BRG clock will be configured by the BRG16 and BRGH bits. Independent of the BRG16 bit setting, both the SPBRG and SPBRGH will be used as a 16-bit counter. This allows the user to verify that no carry occurred for 8-bit modes, by checking for 00h in the SPBRGH register. Refer to Table 16-4 for counter clock rates to the BRG. While the ABD sequence takes place, the EUSART state machine is held in Idle. The RCIF interrupt is set once the fifth rising edge on RX is detected. The value in the RCREG needs to be read to clear the RCIF interrupt. RCREG content should be discarded. 16.2.4 RECEIVING A SYNC (AUTO-BAUD RATE DETECT) To receive a Sync (Auto-Baud Rate Detect): 1. Configure the EUSART for asynchronous receive. TXEN should remain clear. SPBRGH:SPBRG may be left as is. The controller should operate in either PRI_RUN or PRI_IDLE. 2. Enable RXIF interrupts. Set RCIE, PEIE, GIE. 3. Enable Auto-Baud Rate Detect. Set ABDEN. 4. When the next RCIF interrupt occurs, the received baud rate has been measured. Read RCREG to clear RCIF and discard. Check SPBRGH:SPBRG for a valid value. The EUSART is ready for normal communications. Return from the interrupt. Allow the primary clock to run (PRI_RUN or PRI_IDLE). 5. Process subsequent RCIF interrupts normally as in asynchronous reception. Remain in PRI_RUN or PRI_IDLE until communications are complete. TABLE 16-4: BRG COUNTER CLOCK RATES Note 1: It is up to the user to determine that the incoming character baud rate is within the range of the selected BRG clock source. Some combinations of oscillator frequency and EUSART baud rates are not possible due to bit error rates. Overall system timing and communication baud rates must be taken into consideration when using the Auto-Baud Rate Detection feature. BRG16 BRGH BRG Counter Clock 0 0 FOSC/512 0 1 FOSC/128 1 0 FOSC/128 1 1 FOSC/32 Note: During the ABD sequence, SPBRG and SPBRGH are both used as a 16-bit counter, independent of BRG16 setting.PIC18F1220/1320 DS39605F-page 140 © 2007 Microchip Technology Inc. FIGURE 16-1: AUTOMATIC BAUD RATE CALCULATION 16.3 EUSART Asynchronous Mode The Asynchronous mode of operation is selected by clearing the SYNC bit (TXSTA<4>). In this mode, the EUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop bit). The most common data format is 8 bits. An on-chip dedicated 8-bit/16-bit Baud Rate Generator can be used to derive standard baud rate frequencies from the oscillator. The EUSART transmits and receives the LSb first. The EUSART’s transmitter and receiver are functionally independent, but use the same data format and baud rate. The Baud Rate Generator produces a clock, either x16 or x64 of the bit shift rate, depending on the BRGH and BRG16 bits (TXSTA<2> and BAUDCTL<3>). Parity is not supported by the hardware, but can be implemented in software and stored as the 9th data bit. Asynchronous mode is available in all low-power modes; it is available in Sleep mode only when autowake-up on Sync Break is enabled. When in PRI_IDLE mode, no changes to the Baud Rate Generator values are required; however, other low-power mode clocks may operate at another frequency than the primary clock. Therefore, the Baud Rate Generator values may need to be adjusted. When operating in Asynchronous mode, the EUSART module consists of the following important elements: • Baud Rate Generator • Sampling Circuit • Asynchronous Transmitter • Asynchronous Receiver • Auto-Wake-up on Sync Break Character • 12-bit Break Character Transmit • Auto-Baud Rate Detection 16.3.1 EUSART ASYNCHRONOUS TRANSMITTER The EUSART transmitter block diagram is shown in Figure 16-2. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The shift register obtains its data from the Read/Write Transmit Buffer register, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the Stop bit has been transmitted from the previous load. As soon as the Stop bit is transmitted, the TSR is loaded with new data from the TXREG register (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCY), the TXREG register is empty and flag bit, TXIF (PIR1<4>), is set. This interrupt can be enabled/disabled by setting/clearing enable bit, TXIE (PIE1<4>). Flag bit, TXIF, will be set, regardless of the state of enable bit, TXIE, and cannot be cleared in software. Flag bit, TXIF, is not cleared immediately upon loading the Transmit Buffer register, TXREG. TXIF becomes valid in the second instruction cycle following the load instruction. Polling TXIF immediately following a load of TXREG will return invalid results. While flag bit, TXIF, indicates the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. Status bit, TRMT, is a readonly bit, which is set when the TSR register is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. BRG Value RX pin ABDEN bit RCIF bit Bit 0 Bit 1 (Interrupt) Read RCREG BRG Clock Start Set by User Auto-Cleared XXXXh 0000h Edge #1 Bit 2 Bit 3 Edge #2 Bit 4 Bit 5 Edge #3 Bit 6 Bit 7 Edge #4 Edge #5 001Ch Note 1: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0. SPBRG XXXXh 1Ch SPBRGH XXXXh 00h Stop Bit Note 1: The TSR register is not mapped in data memory, so it is not available to the user. 2: Flag bit, TXIF, is set when enable bit, TXEN, is set.© 2007 Microchip Technology Inc. DS39605F-page 141 PIC18F1220/1320 To set up an Asynchronous Transmission: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set transmit bit TX9. Can be used as address/data bit. 5. Enable the transmission by setting bit TXEN, which will also set bit TXIF. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Load data to the TXREG register (starts transmission). If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 16-2: EUSART TRANSMIT BLOCK DIAGRAM FIGURE 16-3: ASYNCHRONOUS TRANSMISSION TXIF TXIE Interrupt TXEN Baud Rate CLK SPBRG Baud Rate Generator TX9D MSb LSb Data Bus TXREG Register TSR Register (8) 0 TX9 TRMT SPEN RB1/AN5/TX/CK/INT1 pin Pin Buffer and Control 8 • • • BRG16 SPBRGH Word 1 Word 1 Transmit Shift Reg Start bit bit 0 bit 1 bit 7/8 Write to TXREG Word 1 BRG Output (Shift Clock) RB1/AN5/TX/ TXIF bit (Transmit Buffer Reg. Empty Flag) TRMT bit (Transmit Shift Reg. Empty Flag) 1 TCY CK/INT1 (pin) Stop bitPIC18F1220/1320 DS39605F-page 142 © 2007 Microchip Technology Inc. FIGURE 16-4: ASYNCHRONOUS TRANSMISSION (BACK TO BACK) TABLE 16-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Transmit Shift Reg. Write to TXREG BRG Output (Shift Clock) RB1/AN5/TX/ TXIF bit (Interrupt Reg. Flag) TRMT bit (Transmit Shift Reg. Empty Flag) Word 1 Word 2 Word 1 Word 2 Stop bit Start bit Transmit Shift Reg. Word 1 Word 2 bit 0 bit 1 bit 7/8 bit 0 Note: This timing diagram shows two consecutive transmissions. 1 TCY 1 TCY CK/INT1 (pin) Start bit Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x TXREG EUSART Transmit Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.© 2007 Microchip Technology Inc. DS39605F-page 143 PIC18F1220/1320 16.3.2 EUSART ASYNCHRONOUS RECEIVER The receiver block diagram is shown in Figure 16-5. The data is received on the RB4/AN6/RX/DT/KBI0 pin and drives the data recovery block. The data recovery block is actually a high-speed shifter, operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. To set up an Asynchronous Reception: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit RCIE. 4. If 9-bit reception is desired, set bit RX9. 5. Enable the reception by setting bit CREN. 6. Flag bit, RCIF, will be set when reception is complete and an interrupt will be generated if enable bit RCIE was set. 7. Read the RCSTA register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG register. 9. If any error occurred, clear the error by clearing enable bit CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 16.3.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RCIP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RCIF bit will be set when reception is complete. The interrupt will be Acknowledged if the RCIE and GIE bits are set. 8. Read the RCSTA register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU. FIGURE 16-5: EUSART RECEIVE BLOCK DIAGRAM x64 Baud Rate CLK Baud Rate Generator RB4/AN6/RX/DT/KBI0 Pin Buffer and Control SPEN Data Recovery CREN OERR FERR MSb RSR Register LSb RX9D RCREG Register FIFO Interrupt RCIF RCIE Data Bus 8 ÷ 64 ÷ 16 or Stop (8) 7 1 0 Start RX9 • • • BRG16 SPBRGH SPBRG or ÷ 4PIC18F1220/1320 DS39605F-page 144 © 2007 Microchip Technology Inc. To set up an Asynchronous Transmission: 1. Initialize the SPBRG register for the appropriate baud rate. If a high-speed baud rate is desired, set bit BRGH (see Section 16.2 “EUSART Baud Rate Generator (BRG)”). 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set transmit bit TX9. Can be used as address/data bit. 5. Enable the transmission by setting bit TXEN, which will also set bit TXIF. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Load data to the TXREG register (starts transmission). If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 16-6: ASYNCHRONOUS RECEPTION TABLE 16-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION Start bit bit 0 bit 7/8 bit 1 Stop bit 0 bit 7/8 bit Start bit Start bit 7/8 Stop bit bit RX (pin) Reg Rcv Buffer Reg Rcv Shift Read Rcv Buffer Reg RCREG RCIF (Interrupt Flag) OERR bit CREN Word 1 RCREG Word 2 RCREG Stop bit Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing the OERR (overrun) bit to be set. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x RCREG EUSART Receive Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.© 2007 Microchip Technology Inc. DS39605F-page 145 PIC18F1220/1320 16.3.4 AUTO-WAKE-UP ON SYNC BREAK CHARACTER During Sleep mode, all clocks to the EUSART are suspended. Because of this, the Baud Rate Generator is inactive and a proper byte reception cannot be performed. The auto-wake-up feature allows the controller to wake-up due to activity on the RX/DT line while the EUSART is operating in Asynchronous mode. The auto-wake-up feature is enabled by setting the WUE bit (BAUDCTL<1>). Once set, the typical receive sequence on RX/DT is disabled and the EUSART remains in an Idle state, monitoring for a wake-up event independent of the CPU mode. A wake-up event consists of a high-to-low transition on the RX/DT line. (This coincides with the start of a Sync Break or a Wake-up Signal character for the LIN protocol.) Following a wake-up event, the module generates an RCIF interrupt. The interrupt is generated synchronously to the Q clocks in normal operating modes (Figure 16-7) and asynchronously if the device is in Sleep mode (Figure 16-8). The interrupt condition is cleared by reading the RCREG register. The WUE bit is automatically cleared once a low-to-high transition is observed on the RX line, following the wakeup event. At this point, the EUSART module is in Idle mode and returns to normal operation. This signals to the user that the Sync Break event is over. 16.3.4.1 Special Considerations Using Auto-Wake-up Since auto-wake-up functions by sensing rising edge transitions on RX/DT, information with any state changes before the Stop bit may signal a false end-of-character and cause data or framing errors. To work properly, therefore, the initial character in the transmission must be all ‘0’s. This can be 00h (8 bytes) for standard RS-232 devices, or 000h (12 bits) for LIN bus. Oscillator start-up time must also be considered, especially in applications using oscillators with longer start-up intervals (i.e., LP, XT or HS/PLL mode). The Sync Break (or Wake-up Signal) character must be of sufficient length and be followed by a sufficient period, to allow enough time for the selected oscillator to start and provide proper initialization of the EUSART. 16.3.4.2 Special Considerations Using the WUE Bit The timing of WUE and RCIF events may cause some confusion when it comes to determining the validity of received data. As noted, setting the WUE bit places the EUSART in an Idle mode. The wake-up event causes a receive interrupt by setting the RCIF bit. The WUE bit is cleared after this when a rising edge is seen on RX/ DT. The interrupt condition is then cleared by reading the RCREG register. Ordinarily, the data in RCREG will be dummy data and should be discarded. The fact that the WUE bit has been cleared (or is still set) and the RCIF flag is set should not be used as an indicator of the integrity of the data in RCREG. Users should consider implementing a parallel method in firmware to verify received data integrity. To assure that no actual data is lost, check the RCIDL bit to verify that a receive operation is not in process. If a receive operation is not occurring, the WUE bit may then be set just prior to entering the Sleep mode. FIGURE 16-7: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION FIGURE 16-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 WUE bit RX/DT Line RCIF Cleared due to User Read of RCREG Note 1: The EUSART remains in Idle while the WUE bit is set. Bit Set by User Cleared by hardware Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 WUE bit RX/DT Line RCIF Cleared due to User Read of RCREG Note 1: If the wake-up event requires a long oscillator warm-up time, the WUE bit may be cleared while the primary clock is still starting. 2: The EUSART remains in Idle while the WUE bit is set. Sleep Ends Enters Sleep Bit Set by User Cleared by hardware Note 1PIC18F1220/1320 DS39605F-page 146 © 2007 Microchip Technology Inc. 16.3.5 BREAK CHARACTER SEQUENCE The Enhanced USART module has the capability of sending the special Break character sequences that are required by the LIN bus standard. The Break character transmit consists of a Start bit, followed by twelve ‘0’ bits and a Stop bit. The Frame Break character is sent whenever the SENDB and TXEN bits (TXSTA<3> and TXSTA<5>) are set while the Transmit Shift register is loaded with data. Note that the value of data written to TXREG will be ignored and all ‘0’s will be transmitted. The SENDB bit is automatically reset by hardware after the corresponding Stop bit is sent. This allows the user to preload the transmit FIFO with the next transmit byte following the Break character (typically, the Sync character in the LIN specification). Note that the data value written to the TXREG for the Break character is ignored. The write simply serves the purpose of initiating the proper sequence. The TRMT bit indicates when the transmit operation is active or Idle, just as it does during normal transmission. See Figure 16-9 for the timing of the Break character sequence. 16.3.5.1 Transmitting A Break Signal The Enhanced USART module has the capability of sending the Break signal that is required by the LIN bus standard. The Break signal consists of a Start bit, followed by twelve ‘0’ bits and a Stop bit. The Break signal is sent whenever the SENDB (TXSTA<3>) and TXEN (TXSTA<5>) bits are set and TXREG is loaded with data. The data written to TXREG will be ignored and all ‘0’s will be transmitted. SENDB is automatically cleared by hardware when the Break signal has been sent. This allows the user to preload the transmit FIFO with the next transmit byte following the Break character (typically, the Sync character in the LIN specification). The TRMT bit indicates when the transmit operation is active or Idle, just as it does during normal transmission. To send a Break Signal: 1. Configure the EUSART for asynchronous transmissions (steps 1-5). Initialize the SPBRG register for the appropriate baud rate. If a high-speed baud rate is desired, set bit BRGH (see Section 16.2 “EUSART Baud Rate Generator (BRG)”). 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set transmit bit TX9. Can be used as address/data bit. 5. Enable the transmission by setting bit TXEN, which will also set bit TXIF. 6. Set the SENDB bit. 7. Load a byte into TXREG. This triggers sending a Break signal. The Break signal is complete when TRMT is set. SENDB will also be cleared. See Figure 16-9 for the timing of the Break signal sequence. 16.3.6 RECEIVING A BREAK CHARACTER The Enhanced USART module can receive a Break character in two ways. The first method forces configuration of the baud rate at a frequency of 9/13 the typical speed. This allows for the Stop bit transition to be at the correct sampling location (12 bits for Break versus Start bit and 8 data bits for typical data). The second method uses the auto-wake-up feature described in Section 16.3.4 “Auto-Wake-up on Sync Break Character”. By enabling this feature, the EUSART will sample the next two transitions on RX/DT, cause an RCIF interrupt and receive the next data byte followed by another interrupt. Note that following a Break character, the user will typically want to enable the Auto-Baud Rate Detect feature. For both methods, the user can set the ABD bit before placing the EUSART in its Sleep mode. 16.3.6.1 Transmitting a Break Sync The following sequence will send a message frame header made up of a Break, followed by an auto-baud Sync byte. This sequence is typical of a LIN bus master. 1. Configure the EUSART for the desired mode. 2. Set the TXEN and SENDB bits to set up the Break character. 3. Load the TXREG with a dummy character to initiate transmission (the value is ignored). 4. Write ‘55h’ to TXREG to load the Sync character into the transmit FIFO buffer. 5. After the Break has been sent, the SENDB bit is reset by hardware. The Sync character now transmits in the preconfigured mode. When the TXREG becomes empty, as indicated by the TXIF, the next data byte can be written to TXREG.© 2007 Microchip Technology Inc. DS39605F-page 147 PIC18F1220/1320 16.3.6.2 Receiving a Break Sync To receive a Break Sync: 1. Configure the EUSART for asynchronous transmit and receive. TXEN should remain clear. SPBRGH:SPBRG may be left as is. 2. Enable auto-wake-up. Set WUE. 3. Enable RXIF interrupts. Set RCIE, PEIE, GIE. 4. The controller may be placed in any power managed mode. 5. An RCIF will be generated at the beginning of the Break signal. When the interrupt is received, read RCREG to clear RCIF and discard. Allow the controller to return to PRI_RUN mode. 6. Wait for the RX line to go high at the end of the Break signal. Wait for any of the following: WUE to clear automatically (poll), RB4/RX to go high (poll) or for RBIF to be set (poll or interrupt). If RBIF is used, check to be sure that RB4/RX is high before continuing. 7. Enable Auto-Baud Rate Detect. Set ABDEN. 8. Return from the interrupt. Allow the primary clock to start and stabilize (PRI_RUN or PRI_IDLE). 9. When the next RCIF interrupt occurs, the received baud rate has been measured. Read RCREG to clear RCIF and discard. Check SPBRGH:SPBRG for a valid value. The EUSART is ready for normal communications. Return from the interrupt. Allow the primary clock to run (PRI_RUN or PRI_IDLE). 10. Process subsequent RCIF interrupts normally as in asynchronous reception. TXEN should now be set if transmissions are needed. TXIF and TXIE may be set if transmit interrupts are desired. Remain in PRI_RUN or PRI_IDLE until communications are complete. Clear TXEN and return to step 2. FIGURE 16-9: SEND BREAK CHARACTER SEQUENCE Write to TXREG BRG Output (Shift Clock) Start Bit Bit 0 Bit 1 Bit 11 Stop Bit Break TXIF bit TX (pin) TRMT bit SENDB Dummy Write PIC18F1220/1320 DS39605F-page 148 © 2007 Microchip Technology Inc. 16.4 EUSART Synchronous Master Mode The Synchronous Master mode is entered by setting the CSRC bit (TXSTA<7>). In this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit, SYNC (TXSTA<4>). In addition, enable bit, SPEN (RCSTA<7>), is set in order to configure the RB1/AN5/ TX/CK/INT1 and RB4/AN6/RX/DT/KBI0 I/O pins to CK (clock) and DT (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK line. Clock polarity is selected with the SCKP bit (BAUDCTL<5>); setting SCKP sets the Idle state on CK as high, while clearing the bit sets the Idle state as low. This option is provided to support Microwire devices with this module. 16.4.1 EUSART SYNCHRONOUS MASTER TRANSMISSION The EUSART transmitter block diagram is shown in Figure 16-2. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The shift register obtains its data from the Read/Write Transmit Buffer register, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG is empty and interrupt bit, TXIF (PIR1<4>), is set. The interrupt can be enabled/disabled by setting/clearing enable bit, TXIE (PIE1<4>). Flag bit, TXIF, will be set, regardless of the state of enable bit, TXIE and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit, TXIF, indicates the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. TRMT is a read-only bit, which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory, so it is not available to the user. To set up a Synchronous Master Transmission: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set bit TX9. 5. Enable the transmission by setting bit TXEN. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Start transmission by loading data to the TXREG register. 8. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 16-10: SYNCHRONOUS TRANSMISSION bit 0 bit 1 bit 7 Word 1 Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3Q4 Q1 Q2Q3Q4 Q1 Q2Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 bit 2 bit 0 bit 1 bit 7 RB4/AN6/RX/ RB1/AN5/TX/ Write to TXREG Reg TXIF bit (Interrupt Flag) TXEN bit ‘1’ ‘1’ Word 2 TRMT bit Write Word 1 Write Word 2 Note: Sync Master mode, SPBRG = 0, continuous transmission of two 8-bit words. DT/KBI0 pin CK/INT1 pin RB1/AN5/TX/ CK/INT1 pin (SCKP = 0) (SCKP = 1)© 2007 Microchip Technology Inc. DS39605F-page 149 PIC18F1220/1320 FIGURE 16-11: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) TABLE 16-7: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION RB4/AN6/RX/DT/KBI0 pin RB1/AN5/TX/CK/INT1 pin Write to TXREG reg TXIF bit TRMT bit bit 0 bit 1 bit 2 bit 6 bit 7 TXEN bit Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x TXREG EUSART Transmit Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.PIC18F1220/1320 DS39605F-page 150 © 2007 Microchip Technology Inc. 16.4.2 EUSART SYNCHRONOUS MASTER RECEPTION Once Synchronous mode is selected, reception is enabled by setting either the Single Receive Enable bit, SREN (RCSTA<5>), or the Continuous Receive Enable bit, CREN (RCSTA<4>). Data is sampled on the RB4/AN6/RX/DT/KBI0 pin on the falling edge of the clock. If enable bit, SREN, is set, only a single word is received. If enable bit, CREN, is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. 3. Ensure bits CREN and SREN are clear. 4. If interrupts are desired, set enable bit RCIE. 5. If 9-bit reception is desired, set bit RX9. 6. If a single reception is required, set bit SREN. For continuous reception, set bit CREN. 7. Interrupt flag bit, RCIF, will be set when reception is complete and an interrupt will be generated if the enable bit, RCIE, was set. 8. Read the RCSTA register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG register. 10. If any error occurred, clear the error by clearing bit CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 16-12: SYNCHRONOUS RECEPTION (MASTER MODE, SREN) CREN bit RB4/AN6/RX/ RB1/AN5/TX/ Write to bit SREN SREN bit RCIF bit (Interrupt) Read RXREG Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 ‘0’ bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 ‘0’ Q1 Q2 Q3 Q4 Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0. RB1/AN5/TX/ CK/INT1 pin CK/INT1 pin DT/KBI0 pin (SCKP = 0) (SCKP = 1)© 2007 Microchip Technology Inc. DS39605F-page 151 PIC18F1220/1320 TABLE 16-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x RCREG EUSART Receive Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.PIC18F1220/1320 DS39605F-page 152 © 2007 Microchip Technology Inc. 16.5 EUSART Synchronous Slave Mode Synchronous Slave mode is entered by clearing bit, CSRC (TXSTA<7>). This mode differs from the Synchronous Master mode in that the shift clock is supplied externally at the RB1/AN5/TX/CK/INT1 pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in any low-power mode. 16.5.1 EUSART SYNCHRONOUS SLAVE TRANSMIT The operation of the Synchronous Master and Slave modes are identical, except in the case of the Sleep mode. If two words are written to the TXREG and then the SLEEP instruction is executed, the following will occur: a) The first word will immediately transfer to the TSR register and transmit. b) The second word will remain in the TXREG register. c) Flag bit, TXIF, will not be set. d) When the first word has been shifted out of TSR, the TXREG register will transfer the second word to the TSR and flag bit, TXIF, will now be set. e) If enable bit, TXIE, is set, the interrupt will wake the chip from Sleep. If the global interrupt is enabled, the program will branch to the interrupt vector. To set up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting bits SYNC and SPEN and clearing bit CSRC. 2. Clear bits CREN and SREN. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set bit TX9. 5. Enable the transmission by setting enable bit TXEN. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Start transmission by loading data to the TXREG register. 8. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 16-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x TXREG EUSART Transmit Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.© 2007 Microchip Technology Inc. DS39605F-page 153 PIC18F1220/1320 16.5.2 EUSART SYNCHRONOUS SLAVE RECEPTION The operation of the Synchronous Master and Slave modes is identical, except in the case of Sleep, or any Idle mode and bit SREN, which is a “don’t care” in Slave mode. If receive is enabled by setting the CREN bit prior to entering Sleep or any Idle mode, then a word may be received while in this low-power mode. Once the word is received, the RSR register will transfer the data to the RCREG register; if the RCIE enable bit is set, the interrupt generated will wake the chip from low-power mode. If the global interrupt is enabled, the program will branch to the interrupt vector. To set up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting bits SYNC and SPEN and clearing bit CSRC. 2. If interrupts are desired, set enable bit RCIE. 3. If 9-bit reception is desired, set bit RX9. 4. To enable reception, set enable bit CREN. 5. Flag bit, RCIF, will be set when reception is complete. An interrupt will be generated if enable bit, RCIE, was set. 6. Read the RCSTA register to get the 9th bit (if enabled) and determine if any error occurred during reception. 7. Read the 8-bit received data by reading the RCREG register. 8. If any error occurred, clear the error by clearing bit CREN. 9. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x RCREG EUSART Receive Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010 BAUDCTL — RCIDL — SCKP BRG16 — WUE ABDEN -1-1 0-00 -1-1 0-00 SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000 SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000 Legend: x = unknown, – = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.PIC18F1220/1320 DS39605F-page 154 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 155 PIC18F1220/1320 17.0 10-BIT ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE The Analog-to-Digital (A/D) converter module has seven inputs for the PIC18F1220/1320 devices. This module allows conversion of an analog input signal to a corresponding 10-bit digital number. A new feature for the A/D converter is the addition of programmable acquisition time. This feature allows the user to select a new channel for conversion and to set the GO/DONE bit immediately. When the GO/DONE bit is set, the selected channel is sampled for the programmed acquisition time before a conversion is actually started. This removes the firmware overhead that may have been required to allow for an acquisition (sampling) period (see Register 17-3 and Section 17.3 “Selecting and Configuring Automatic Acquisition Time”). The module has five registers: • A/D Result High Register (ADRESH) • A/D Result Low Register (ADRESL) • A/D Control Register 0 (ADCON0) • A/D Control Register 1 (ADCON1) • A/D Control Register 2 (ADCON2) The ADCON0 register, shown in Register 17-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 17-2, configures the functions of the port pins. The ADCON2 register, shown in Register 17-3, configures the A/D clock source, programmed acquisition time and justification. REGISTER 17-1: ADCON0: A/D CONTROL REGISTER 0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 VCFG1 VCFG0 — CHS2 CHS1 CHS0 GO/DONE ADON bit 7 bit 0 bit 7-6 VCFG<1:0>: Voltage Reference Configuration bits bit 5 Unimplemented: Read as ‘0’ bit 4-2 CHS2:CHS0: Analog Channel Select bits 000 = Channel 0 (AN0) 001 = Channel 1 (AN1) 010 = Channel 2 (AN2) 011 = Channel 3 (AN3) 100 = Channel 4 (AN4) 101 = Channel 5 (AN5) 110 = Channel 6 (AN6) 111 = Unimplemented(1) bit 1 GO/DONE: A/D Conversion Status bit When ADON = 1: 1 = A/D conversion in progress 0 = A/D Idle bit 0 ADON: A/D On bit 1 = A/D converter module is enabled 0 = A/D converter module is disabled Note 1: Performing a conversion on unimplemented channels returns full-scale results. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown A/D VREF+ A/D VREF- 00 AVDD AVSS 01 External VREF+ AVSS 10 AVDD External VREF- 11 External VREF+ External VREF-PIC18F1220/1320 DS39605F-page 156 © 2007 Microchip Technology Inc. REGISTER 17-2: ADCON1: A/D CONTROL REGISTER 1 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — PCFG6 PCFG5 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 PCFG6: A/D Port Configuration bit – AN6 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ bit 5 PCFG5: A/D Port Configuration bit – AN5 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ bit 4 PCFG4: A/D Port Configuration bit – AN4 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ bit 3 PCFG3: A/D Port Configuration bit – AN3 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ bit 2 PCFG2: A/D Port Configuration bit – AN2 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ bit 1 PCFG1: A/D Port Configuration bit – AN1 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ bit 0 PCFG0: A/D Port Configuration bit – AN0 1 = Pin configured as a digital port 0 = Pin configured as an analog channel – digital input disabled and reads ‘0’ Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown© 2007 Microchip Technology Inc. DS39605F-page 157 PIC18F1220/1320 REGISTER 17-3: ADCON2: A/D CONTROL REGISTER 2 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 bit 7 bit 0 bit 7 ADFM: A/D Result Format Select bit 1 = Right justified 0 = Left justified bit 6 Unimplemented: Read as ‘0’ bit 5-3 ACQT2:ACQT0: A/D Acquisition Time Select bits 000 = 0 TAD(1) 001 = 2 TAD 010 = 4 TAD 011 = 6 TAD 100 = 8 TAD 101 = 12 TAD 110 = 16 TAD 111 = 20 TAD bit 2-0 ADCS2:ADCS0: A/D Conversion Clock Select bits 000 = FOSC/2 001 = FOSC/8 010 = FOSC/32 011 = FRC (clock derived from A/D RC oscillator)(1) 100 = FOSC/4 101 = FOSC/16 110 = FOSC/64 111 = FRC (clock derived from A/D RC oscillator)(1) Note: If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D clock starts. This allows the SLEEP instruction to be executed before starting a conversion. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 158 © 2007 Microchip Technology Inc. The analog reference voltage is software selectable to either the device’s positive and negative supply voltage (AVDD and AVSS), or the voltage level on the RA3/AN3/VREF+ and RA2/AN2/VREF- pins. The A/D converter has a unique feature of being able to operate while the device is in Sleep mode. To operate in Sleep, the A/D conversion clock must be derived from the A/D’s internal RC oscillator. The output of the sample and hold is the input into the converter, which generates the result via successive approximation. A device Reset forces all registers to their Reset state. This forces the A/D module to be turned off and any conversion in progress is aborted. Each port pin associated with the A/D converter can be configured as an analog input, or as a digital I/O. The ADRESH and ADRESL registers contain the result of the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH/ADRESL registers, the GO/DONE bit (ADCON0 register) is cleared and A/D Interrupt Flag bit, ADIF, is set. The block diagram of the A/D module is shown in Figure 17-1. FIGURE 17-1: A/D BLOCK DIAGRAM (Input Voltage) VAIN VREFH Reference Voltage AVDD VCFG1:VCFG0 CHS2:CHS0 AN6(1) AN5 AN4 AN3/VREF+ AN2/VREFAN1 AN0 111 110 101 100 011 010 001 000 10-bit Converter VREFL AVSS A/D Note 1: I/O pins have diode protection to VDD and VSS. 0x 1x x1 x0 AVDD© 2007 Microchip Technology Inc. DS39605F-page 159 PIC18F1220/1320 The value in the ADRESH/ADRESL registers is not modified for a Power-on Reset. The ADRESH/ADRESL registers will contain unknown data after a Power-on Reset. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as an input. To determine acquisition time, see Section 17.1 “A/D Acquisition Requirements”. After this acquisition time has elapsed, the A/D conversion can be started. An acquisition time can be programmed to occur between setting the GO/DONE bit and the actual start of the conversion. To do an A/D Conversion: 1. Configure the A/D module: • Configure analog pins, voltage reference and digital I/O (ADCON1) • Select A/D input channel (ADCON0) • Select A/D acquisition time (ADCON2) • Select A/D conversion clock (ADCON2) • Turn on A/D module (ADCON0) 2. Configure A/D interrupt (if desired): • Clear ADIF bit • Set ADIE bit • Set GIE bit 3. Wait the required acquisition time (if required). 4. Start conversion: • Set GO/DONE bit (ADCON0 register) 5. Wait for A/D conversion to complete, by either: • Polling for the GO/DONE bit to be cleared OR • Waiting for the A/D interrupt 6. Read A/D Result registers (ADRESH:ADRESL); clear bit, ADIF, if required. 7. For the next conversion, go to step 1 or step 2, as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2 TAD is required before the next acquisition starts. FIGURE 17-2: ANALOG INPUT MODEL VAIN CPIN Rs ANx 5 pF VDD VT = 0.6V VT = 0.6V ILEAKAGE RIC ≤ 1k Sampling Switch SS RSS CHOLD = 120 pF VSS 6V Sampling Switch 5V 4V 3V 2V 5 6 7 8 9 10 11 (kΩ) VDD ± 500 nA Legend: CPIN = input capacitance VT = threshold voltage ILEAKAGE = leakage current at the pin due to various junctions RIC = interconnect resistance SS = sampling switch CHOLD = sample/hold capacitance (from DAC) RSS = sampling switch resistancePIC18F1220/1320 DS39605F-page 160 © 2007 Microchip Technology Inc. 17.1 A/D Acquisition Requirements For the A/D converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 17-2. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD). The source impedance affects the offset voltage at the analog input (due to pin leakage current). The maximum recommended impedance for analog sources is 2.5 kΩ. After the analog input channel is selected (changed), the channel must be sampled for at least the minimum acquisition time before starting a conversion. To calculate the minimum acquisition time, Equation 17-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. Example 17-1 shows the calculation of the minimum required acquisition time, TACQ. This calculation is based on the following application system assumptions: CHOLD = 120 pF Rs = 2.5 kΩ Conversion Error ≤ 1/2 LSb VDD = 5V → RSS = 7 kΩ Temperature = 50°C (system max.) VHOLD = 0V @ time = 0 17.2 A/D VREF+ and VREF- References If external voltage references are used instead of the internal AVDD and AVSS sources, the source impedance of the VREF+ and VREF- voltage sources must be considered. During acquisition, currents supplied by these sources are insignificant. However, during conversion, the A/D module sinks and sources current through the reference sources. In order to maintain the A/D accuracy, the voltage reference source impedances should be kept low to reduce voltage changes. These voltage changes occur as reference currents flow through the reference source impedance. The maximum recommended impedance of the VREF+ and VREF- external reference voltage sources is 250Ω. EQUATION 17-1: ACQUISITION TIME EQUATION 17-2: A/D MINIMUM CHARGING TIME EXAMPLE 17-1: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME Note: When the conversion is started, the holding capacitor is disconnected from the input pin. TACQ = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient = TAMP + TC + TCOFF VHOLD = (ΔVREF – (ΔVREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS))) or TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048) TACQ =TAMP + TC + TCOFF TAMP = 5 μs TCOFF = (Temp – 25ºC)(0.05 μs/ºC) (50ºC – 25ºC)(0.05 μs/ºC) 1.25 μs Temperature coefficient is only required for temperatures > 25ºC. Below 25ºC, TCOFF = 0 μs. TC = -(CHOLD)(RIC + RSS + RS) ln(1/2047) μs -(120 pF) (1 kΩ + 7 kΩ + 2.5 kΩ) ln(0.0004883) μs 9.61 μs TACQ = 5 μs + 1.25 μs + 9.61 μs 12.86 μs© 2007 Microchip Technology Inc. DS39605F-page 161 PIC18F1220/1320 17.3 Selecting and Configuring Automatic Acquisition Time The ADCON2 register allows the user to select an acquisition time that occurs each time the GO/DONE bit is set. When the GO/DONE bit is set, sampling is stopped and a conversion begins. The user is responsible for ensuring the required acquisition time has passed between selecting the desired input channel and setting the GO/DONE bit. This occurs when the ACQT2:ACQT0 bits (ADCON2<5:3>) remain in their Reset state (‘000’) and is compatible with devices that do not offer programmable acquisition times. If desired, the ACQT bits can be set to select a programmable acquisition time for the A/D module. When the GO/DONE bit is set, the A/D module continues to sample the input for the selected acquisition time, then automatically begins a conversion. Since the acquisition time is programmed, there may be no need to wait for an acquisition time between selecting a channel and setting the GO/DONE bit. In either case, when the conversion is completed, the GO/DONE bit is cleared, the ADIF flag is set and the A/D begins sampling the currently selected channel again. If an acquisition time is programmed, there is nothing to indicate if the acquisition time has ended or if the conversion has begun. 17.4 Selecting the A/D Conversion Clock The A/D conversion time per bit is defined as TAD. The A/D conversion requires 11 TAD per 10-bit conversion. The source of the A/D conversion clock is software selectable. There are seven possible options for TAD: • 2 TOSC • 4 TOSC • 8 TOSC • 16 TOSC • 32 TOSC • 64 TOSC • Internal RC oscillator For correct A/D conversions, the A/D conversion clock (TAD) must be as short as possible, but greater than the minimum TAD (approximately 2 μs, see parameter 130 for more information). Table 17-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. TABLE 17-1: TAD vs. DEVICE OPERATING FREQUENCIES AD Clock Source (TAD) Maximum Device Frequency Operation ADCS2:ADCS0 PIC18F1220/1320 PIC18LF1220/1320(4) 2 TOSC 000 1.25 MHz 666 kHz 4 TOSC 100 2.50 MHz 1.33 MHz 8 TOSC 001 5.00 MHz 2.66 MHz 16 TOSC 101 10.0 MHz 5.33 MHz 32 TOSC 010 20.0 MHz 10.65 MHz 64 TOSC 110 40.0 MHz 21.33 MHz RC(3) x11 1.00 MHz(1) 1.00 MHz(2) Note 1: The RC source has a typical TAD time of 4 μs. 2: The RC source has a typical TAD time of 6 μs. 3: For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or the A/D accuracy may be out of specification. 4: Low-power devices only.PIC18F1220/1320 DS39605F-page 162 © 2007 Microchip Technology Inc. 17.5 Operation in Low-Power Modes The selection of the automatic acquisition time and the A/D conversion clock is determined, in part, by the lowpower mode clock source and frequency while in a low-power mode. If the A/D is expected to operate while the device is in a low-power mode, the ACQT2:ACQT0 and ADCS2:ADCS0 bits in ADCON2 should be updated in accordance with the low-power mode clock that will be used. After the low-power mode is entered (either of the Run modes), an A/D acquisition or conversion may be started. Once an acquisition or conversion is started, the device should continue to be clocked by the same low-power mode clock source until the conversion has been completed. If desired, the device may be placed into the corresponding low-power (ANY)_IDLE mode during the conversion. If the low-power mode clock frequency is less than 1 MHz, the A/D RC clock source should be selected. Operation in the Low-Power Sleep mode requires the A/D RC clock to be selected. If bits, ACQT2:ACQT0, are set to ‘000’ and a conversion is started, the conversion will be delayed one instruction cycle to allow execution of the SLEEP instruction and entry to Low-Power Sleep mode. The IDLEN and SCS bits in the OSCCON register must have already been cleared prior to starting the conversion. 17.6 Configuring Analog Port Pins The ADCON1, TRISA and TRISB registers all configure the A/D port pins. The port pins needed as analog inputs must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS2:CHS0 bits and the TRIS bits. Note 1: When reading the Port register, all pins configured as analog input channels will read as cleared (a low level). Pins configured as digital inputs will convert an analog input. Analog levels on a digitally configured input will be accurately converted. 2: Analog levels on any pin defined as a digital input may cause the digital input buffer to consume current out of the device’s specification limits.© 2007 Microchip Technology Inc. DS39605F-page 163 PIC18F1220/1320 17.7 A/D Conversions Figure 17-3 shows the operation of the A/D converter after the GO bit has been set and the ACQT2:ACQT0 bits are cleared. A conversion is started after the following instruction to allow entry into Low-Power Sleep mode before the conversion begins. Figure 17-4 shows the operation of the A/D converter after the GO bit has been set and the ACQT2:ACQT0 bits are set to ‘010’ and selecting a 4 TAD acquisition time before the conversion starts. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D Result register pair will NOT be updated with the partially completed A/D conversion sample. This means the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is completed or aborted, a 2 TAD wait is required before the next acquisition can be started. After this wait, acquisition on the selected channel is automatically started. FIGURE 17-3: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0) FIGURE 17-4: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD) Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D. TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD11 Set GO bit Holding capacitor is disconnected from analog input (typically 100 ns) TCY – TAD TAD9 TAD10 Next Q4: ADRESH/ADRESL is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. Conversion Starts b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 1 2 3 4 5 6 7 8 11 Set GO bit (Holding capacitor is disconnected) 9 10 Next Q4: ADRESH:ADRESL is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is reconnected to analog input. Conversion Starts 1 2 3 4 (Holding capacitor continues acquiring input) TACQT Cycles TAD Cycles Automatic Acquisition Time b9 b8 b7 b6 b5 b4 b3 b2 b1 b0PIC18F1220/1320 DS39605F-page 164 © 2007 Microchip Technology Inc. 17.8 Use of the CCP1 Trigger An A/D conversion can be started by the “special event trigger” of the CCP1 module. This requires that the CCP1M3:CCP1M0 bits (CCP1CON<3:0>) be programmed as ‘1011’ and that the A/D module is enabled (ADON bit is set). When the trigger occurs, the GO/DONE bit will be set, starting the A/D acquisition and conversion and the Timer1 (or Timer3) counter will be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal software overhead (moving ADRESH/ADRESL to the desired location). The appropriate analog input channel must be selected and the minimum acquisition period is either timed by the user, or an appropriate TACQ time selected before the “special event trigger” sets the GO/DONE bit (starts a conversion). If the A/D module is not enabled (ADON is cleared), the “special event trigger” will be ignored by the A/D module, but will still reset the Timer1 (or Timer3) counter. TABLE 17-2: SUMMARY OF A/D REGISTERS Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on all other Resets INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 0000 0000 0000 PIR1 — ADIF RCIF TXIF — CCP1IF TMR2IF TMR1IF -000 -000 -000 -000 PIE1 — ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE -000 -000 -000 -000 IPR1 — ADIP RCIP TXIP — CCP1IP TMR2IP TMR1IP -111 -111 -111 -111 PIR2 OSCFIF — — EEIF — LVDIF TMR3IF — 0--0 -00- 0--0 -00- PIE2 OSCFIE — — EEIE — LVDIE TMR3IE — 0--0 -00- 0--0 -00- IPR2 OSCFIP — — EEIP — LVDIP TMR3IP — 1--1 -11- 1--1 -11- ADRESH A/D Result Register High Byte xxxx xxxx uuuu uuuu ADRESL A/D Result Register Low Byte xxxx xxxx uuuu uuuu ADCON0 VCFG1 VCFG0 — CHS2 CHS1 CHS0 GO/DONE ADON 00-0 0000 00-0 0000 ADCON1 — PCFG6 PCFG5 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 -000 0000 -000 0000 ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0-00 0000 0-00 0000 PORTA RA7(3) RA6(2) RA5(1) RA4 RA3 RA2 RA1 RA0 qq0x 0000 uu0u 0000 TRISA TRISA7(3) TRISA6(2) — PORTA Data Direction Register qq-1 1111 11-1 1111 PORTB Read PORTB pins, Write LATB Latch xxxx xxxx uuuu uuuu TRISB PORTB Data Direction Register 1111 1111 1111 1111 LATB PORTB Output Data Latch xxxx xxxx uuuu uuuu Legend: x = unknown, u = unchanged, q = depends on CONFIG1H<3:0>, – = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion. Note 1: RA5 port bit is available only as an input pin when the MCLRE bit in the configuration register is ‘0’. 2: RA6 and TRISA6 are available only when the primary oscillator mode selection offers RA6 as a port pin; otherwise, RA6 always reads ‘0’, TRISA6 always reads ‘1’ and writes to both are ignored (see CONFIG1H<3:0>). 3: RA7 and TRISA7 are available only when the internal RC oscillator is configured as the primary oscillator in CONFIG1H<3:0>; otherwise, RA7 always reads ‘0’, TRISA7 always reads ‘1’ and writes to both are ignored.© 2007 Microchip Technology Inc. DS39605F-page 165 PIC18F1220/1320 18.0 LOW-VOLTAGE DETECT In many applications, the ability to determine if the device voltage (VDD) is below a specified voltage level is a desirable feature. A window of operation for the application can be created, where the application software can do “housekeeping tasks”, before the device voltage exits the valid operating range. This can be done using the Low-Voltage Detect module. This module is a software programmable circuitry, where a device voltage trip point can be specified. When the voltage of the device becomes lower then the specified point, an interrupt flag is set. If the interrupt is enabled, the program execution will branch to the interrupt vector address and the software can then respond to that interrupt source. The Low-Voltage Detect circuitry is completely under software control. This allows the circuitry to be turned off by the software, which minimizes the current consumption for the device. Figure 18-1 shows a possible application voltage curve (typically for batteries). Over time, the device voltage decreases. When the device voltage equals voltage VA, the LVD logic generates an interrupt. This occurs at time TA. The application software then has the time, until the device voltage is no longer in valid operating range, to shut down the system. Voltage point VB is the minimum valid operating voltage specification. This occurs at time TB. The difference, TB – TA, is the total time for shutdown. The block diagram for the LVD module is shown in Figure 18-2 (following page). A comparator uses an internally generated reference voltage as the set point. When the selected tap output of the device voltage crosses the set point (is lower than), the LVDIF bit is set. Each node in the resistor divider represents a “trip point” voltage. The “trip point” voltage is the minimum supply voltage level at which the device can operate before the LVD module asserts an interrupt. When the supply voltage is equal to the trip point, the voltage tapped off of the resistor array is equal to the 1.2V internal reference voltage generated by the voltage reference module. The comparator then generates an interrupt signal setting the LVDIF bit. This voltage is software programmable to any one of 16 values (see Figure 18-2). The trip point is selected by programming the LVDL3:LVDL0 bits (LVDCON<3:0>). FIGURE 18-1: TYPICAL LOW-VOLTAGE DETECT APPLICATION Time Voltage VA VB TA TB Legend: VA = LVD trip point VB = Minimum valid device operating voltagePIC18F1220/1320 DS39605F-page 166 © 2007 Microchip Technology Inc. FIGURE 18-2: LOW-VOLTAGE DETECT (LVD) BLOCK DIAGRAM The LVD module has an additional feature that allows the user to supply the trip voltage to the module from an external source. This mode is enabled when bits, LVDL3:LVDL0, are set to ‘1111’. In this state, the comparator input is multiplexed from the external input pin, LVDIN (Figure 18-3). This gives users flexibility, because it allows them to configure the Low-Voltage Detect interrupt to occur at any voltage in the valid operating range. FIGURE 18-3: LOW-VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM LVDIF VDD 16-to-1 MUX LVDEN LVD Control Register Internally Generated Reference Voltage LVDIN 1.2V LVD EN LVD Control 16-to-1 MUX BGAP BODEN LVDEN VxEN LVDIN Register VDD VDD Externally Generated Trip Point© 2007 Microchip Technology Inc. DS39605F-page 167 PIC18F1220/1320 18.1 Control Register The Low-Voltage Detect Control register controls the operation of the Low-Voltage Detect circuitry. REGISTER 18-1: LVDCON REGISTER U-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1 — — IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 bit 7 bit 0 bit 7-6 Unimplemented: Read as ‘0’ bit 5 IRVST: Internal Reference Voltage Stable Flag bit 1 = Indicates that the Low-Voltage Detect logic will generate the interrupt flag at the specified voltage range 0 = Indicates that the Low-Voltage Detect logic will not generate the interrupt flag at the specified voltage range and the LVD interrupt should not be enabled bit 4 LVDEN: Low-Voltage Detect Power Enable bit 1 = Enables LVD, powers up LVD circuit 0 = Disables LVD, powers down LVD circuit bit 3-0 LVDL3:LVDL0: Low-Voltage Detection Limit bits 1111 = External analog input is used (input comes from the LVDIN pin) 1110 = 4.04V-5.15V 1101 = 3.76V-4.79V 1100 = 3.58V-4.56V 1011 = 3.41V-4.34V 1010 = 3.23V-4.11V 1001 = 3.14V-4.00V 1000 = 2.96V-3.77V 0111 = 2.70V-3.43V 0110 = 2.53V-3.21V 0101 = 2.43V-3.10V 0100 = 2.25V-2.86V 0011 = 2.16V-2.75V 0010 = 1.99V-2.53V 0001 = Reserved 0000 = Reserved Note: LVDL3:LVDL0 modes, which result in a trip point below the valid operating voltage of the device, are not tested. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknownPIC18F1220/1320 DS39605F-page 168 © 2007 Microchip Technology Inc. 18.2 Operation Depending on the power source for the device voltage, the voltage normally decreases relatively slowly. This means that the LVD module does not need to be constantly operating. To decrease the current requirements, the LVD circuitry only needs to be enabled for short periods, where the voltage is checked. After doing the check, the LVD module may be disabled. Each time that the LVD module is enabled, the circuitry requires some time to stabilize. After the circuitry has stabilized, all status flags may be cleared. The module will then indicate the proper state of the system. The following steps are needed to set up the LVD module: 1. Write the value to the LVDL3:LVDL0 bits (LVDCON register), which selects the desired LVD trip point. 2. Ensure that LVD interrupts are disabled (the LVDIE bit is cleared or the GIE bit is cleared). 3. Enable the LVD module (set the LVDEN bit in the LVDCON register). 4. Wait for the LVD module to stabilize (the IRVST bit to become set). 5. Clear the LVD interrupt flag, which may have falsely become set, until the LVD module has stabilized (clear the LVDIF bit). 6. Enable the LVD interrupt (set the LVDIE and the GIE bits). Figure 18-4 shows typical waveforms that the LVD module may be used to detect. FIGURE 18-4: LOW-VOLTAGE DETECT WAVEFORMS VLVD VDD LVDIF VLVD VDD Enable LVD Internally Generated TIVRST LVDIF may not be set. Enable LVD LVDIF LVDIF cleared in software LVDIF cleared in software LVDIF cleared in software, CASE 1: CASE 2: LVDIF remains set since LVD condition still exists Reference Stable Internally Generated Reference Stable TIVRST© 2007 Microchip Technology Inc. DS39605F-page 169 PIC18F1220/1320 18.2.1 REFERENCE VOLTAGE SET POINT The internal reference voltage of the LVD module may be used by other internal circuitry (the programmable Brown-out Reset). If these circuits are disabled (lower current consumption), the reference voltage circuit requires a time to become stable before a low-voltage condition can be reliably detected. This time is invariant of system clock speed. This start-up time is specified in electrical specification parameter 36. The low-voltage interrupt flag will not be enabled until a stable reference voltage is reached. Refer to the waveform in Figure 18-4. 18.2.2 CURRENT CONSUMPTION When the module is enabled, the LVD comparator and voltage divider are enabled and will consume static current. The voltage divider can be tapped from multiple places in the resistor array. Total current consumption, when enabled, is specified in electrical specification parameter D022B. 18.3 Operation During Sleep When enabled, the LVD circuitry continues to operate during Sleep. If the device voltage crosses the trip point, the LVDIF bit will be set and the device will wakeup from Sleep. Device execution will continue from the interrupt vector address if interrupts have been globally enabled. 18.4 Effects of a Reset A device Reset forces all registers to their Reset state. This forces the LVD module to be turned off. PIC18F1220/1320 DS39605F-page 170 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 171 PIC18F1220/1320 19.0 SPECIAL FEATURES OF THE CPU PIC18F1220/1320 devices include several features intended to maximize system reliability, minimize cost through elimination of external components and offer code protection. These are: • Oscillator Selection • Resets: - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) • Interrupts • Watchdog Timer (WDT) • Fail-Safe Clock Monitor • Two-Speed Start-up • Code Protection • ID Locations • In-Circuit Serial Programming Several oscillator options are available to allow the part to fit the application. The RC oscillator option saves system cost, while the LP crystal option saves power. These are discussed in detail in Section 2.0 “Oscillator Configurations”. A complete discussion of device Resets and interrupts is available in previous sections of this data sheet. In addition to their Power-up and Oscillator Start-up Timers provided for Resets, PIC18F1220/1320 devices have a Watchdog Timer, which is either permanently enabled via the configuration bits, or software controlled (if configured as disabled). The inclusion of an internal RC oscillator also provides the additional benefits of a Fail-Safe Clock Monitor (FSCM) and Two-Speed Start-up. FSCM provides for background monitoring of the peripheral clock and automatic switchover in the event of its failure. TwoSpeed Start-up enables code to be executed almost immediately on start-up, while the primary clock source completes its start-up delays. All of these features are enabled and configured by setting the appropriate configuration register bits. 19.1 Configuration Bits The configuration bits can be programmed (read as ‘0’), or left unprogrammed (read as ‘1’), to select various device configurations. These bits are mapped starting at program memory location 300000h. The user will note that address 300000h is beyond the user program memory space. In fact, it belongs to the configuration memory space (300000h-3FFFFFh), which can only be accessed using table reads and table writes. Programming the configuration registers is done in a manner similar to programming the Flash memory. The EECON1 register WR bit starts a self-timed write to the configuration register. In normal operation mode, a TBLWT instruction, with the TBLPTR pointing to the configuration register, sets up the address and the data for the configuration register write. Setting the WR bit starts a long write to the configuration register. The configuration registers are written a byte at a time. To write or erase a configuration cell, a TBLWT instruction can write a ‘1’ or a ‘0’ into the cell. For additional details on Flash programming, refer to Section 6.5 “Writing to Flash Program Memory”. TABLE 19-1: CONFIGURATION BITS AND DEVICE IDS File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Default/ Unprogrammed Value 300001h CONFIG1H IESO FSCM — — FOSC3 FOSC2 FOSC1 FOSC0 11-- 1111 300002h CONFIG2L — — — — BORV1 BORV0 BOR PWRTEN ---- 1111 300003h CONFIG2H — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDT ---1 1111 300005h CONFIG3H MCLRE — — — — — — — 1--- ---- 300006h CONFIG4L DEBUG — — — — LVP — STVR 1--- -1-1 300008h CONFIG5L — — — — — — CP1 CP0 ---- --11 300009h CONFIG5H CPD CPB — — — — — — 11-- ---- 30000Ah CONFIG6L — — — — — — WRT1 WRT0 ---- --11 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 111- ---- 30000Ch CONFIG7L — — — — — — EBTR1 EBTR0 ---- --11 30000Dh CONFIG7H — EBTRB — — — — — — -1-- ---- 3FFFFEh DEVID1(1) DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 xxxx xxxx(1) 3FFFFFh DEVID2(1) DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0000 0111 Legend: x = unknown, u = unchanged, – = unimplemented. Shaded cells are unimplemented, read as ‘0’. Note 1: See Register 19-14 for DEVID1 values. DEVID registers are read-only and cannot be programmed by the user.PIC18F1220/1320 DS39605F-page 172 © 2007 Microchip Technology Inc. REGISTER 19-1: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h) R/P-1 R/P-1 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 IESO FSCM — — FOSC3 FOSC2 FOSC1 FOSC0 bit 7 bit 0 bit 7 IESO: Internal External Switchover bit 1 = Internal External Switchover mode enabled 0 = Internal External Switchover mode disabled bit 6 FSCM: Fail-Safe Clock Monitor Enable bit 1 = Fail-Safe Clock Monitor enabled 0 = Fail-Safe Clock Monitor disabled bit 5-4 Unimplemented: Read as ‘0’ bit 3-0 FOSC<3:0>: Oscillator Selection bits 11xx = External RC oscillator, CLKO function on RA6 1001 = Internal RC oscillator, CLKO function on RA6 and port function on RA7 1000 = Internal RC oscillator, port function on RA6 and port function on RA7 0111 = External RC oscillator, port function on RA6 0110 = HS oscillator, PLL enabled (clock frequency = 4 x FOSC1) 0101 = EC oscillator, port function on RA6 0100 = EC oscillator, CLKO function on RA6 0010 = HS oscillator 0001 = XT oscillator 0000 = LP oscillator Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state© 2007 Microchip Technology Inc. DS39605F-page 173 PIC18F1220/1320 REGISTER 19-2: CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h) U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 — — — — BORV1 BORV0 BOR PWRTEN bit 7 bit 0 bit 7-4 Unimplemented: Read as ‘0’ bit 3-2 BORV1:BORV0: Brown-out Reset Voltage bits 11 = Reserved 10 = VBOR set to 2.7V 01 = VBOR set to 4.2V 00 = VBOR set to 4.5V bit 1 BOR: Brown-out Reset Enable bit(1) 1 = Brown-out Reset enabled 0 = Brown-out Reset disabled bit 0 PWRTEN: Power-up Timer Enable bit(1) 1 = PWRT disabled 0 = PWRT enabled Note 1: The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently controlled. Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed statePIC18F1220/1320 DS39605F-page 174 © 2007 Microchip Technology Inc. REGISTER 19-3: CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h) U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN bit 7 bit 0 bit 7-5 Unimplemented: Read as ‘0’ bit 4-1 WDTPS<3:0>: Watchdog Timer Postscale Select bits 1111 = 1:32,768 1110 = 1:16,384 1101 = 1:8,192 1100 = 1:4,096 1011 = 1:2,048 1010 = 1:1,024 1001 = 1:512 1000 = 1:256 0111 = 1:128 0110 = 1:64 0101 = 1:32 0100 = 1:16 0011 = 1:8 0010 = 1:4 0001 = 1:2 0000 = 1:1 bit 0 WDT: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled (control is placed on the SWDTEN bit) Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state© 2007 Microchip Technology Inc. DS39605F-page 175 PIC18F1220/1320 REGISTER 19-4: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h) REGISTER 19-5: CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h) R/P-1 U-0 U-0 U-0 U-0 U-0 U-0 U-0 MCLRE — — — — — — — bit 7 bit 0 bit 7 MCLRE: MCLR Pin Enable bit 1 = MCLR pin enabled, RA5 input pin disabled 0 = RA5 input pin enabled, MCLR disabled bit 6-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state R/P-1 U-0 U-0 U-0 U-0 R/P-1 U-0 R/P-1 DEBUG — — — — LVP — STVR bit 7 bit 0 bit 7 DEBUG: Background Debugger Enable bit (see note) 1 = Background debugger disabled, RB6 and RB7 configured as general purpose I/O pins 0 = Background debugger enabled, RB6 and RB7 are dedicated to In-Circuit Debug bit 6-3 Unimplemented: Read as ‘0’ bit 2 LVP: Low-Voltage ICSP Enable bit 1 = Low-Voltage ICSP enabled 0 = Low-Voltage ICSP disabled bit 1 Unimplemented: Read as ‘0’ bit 0 STVR: Stack Full/Underflow Reset Enable bit 1 = Stack full/underflow will cause Reset 0 = Stack full/underflow will not cause Reset Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state Note: The Timer1 oscillator shares the T1OSI and T1OSO pins with the PGD and PGC pins used for programming and debugging. When using the Timer1 oscillator, In-Circuit Serial Programming (ICSP) may not function correctly (high voltage or low voltage), or the In-Circuit Debugger (ICD) may not communicate with the controller. As a result of using either ICSP or ICD, the Timer1 crystal may be damaged. If ICSP or ICD operations are required, the crystal should be disconnected from the circuit (disconnect either lead) or installed after programming. The oscillator loading capacitors may remain in-circuit during ICSP or ICD operation. PIC18F1220/1320 DS39605F-page 176 © 2007 Microchip Technology Inc. REGISTER 19-6: CONFIG5L: CONFIGURATION REGISTER 5 LOW (BYTE ADDRESS 300008h) REGISTER 19-7: CONFIG5H: CONFIGURATION REGISTER 5 HIGH (BYTE ADDRESS 300009h) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — — — CP1 CP0 bit 7 bit 0 bit 7-2 Unimplemented: Read as ‘0’ bit 1 CP1: Code Protection bit (PIC18F1320) 1 = Block 1 (001000-001FFFh) not code-protected 0 = Block 1 (001000-001FFFh) code-protected bit 0 CP0: Code Protection bit (PIC18F1320) 1 = Block 0 (00200-000FFFh) not code-protected 0 = Block 0 (00200-000FFFh) code-protected bit 1 CP1: Code Protection bit (PIC18F1220) 1 = Block 1 (000800-000FFFh) not code-protected 0 = Block 1 (000800-000FFFh) code-protected bit 0 CP0: Code Protection bit (PIC18F1220) 1 = Block 0 (000200-0007FFh) not code-protected 0 = Block 0 (000200-0007FFh) code-protected Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state R/C-1 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 CPD CPB — — — — — — bit 7 bit 0 bit 7 CPD: Data EEPROM Code Protection bit 1 = Data EEPROM not code-protected 0 = Data EEPROM code-protected bit 6 CPB: Boot Block Code Protection bit 1 = Boot Block (000000-0001FFh) not code-protected 0 = Boot Block (000000-0001FFh) code-protected bit 5-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state© 2007 Microchip Technology Inc. DS39605F-page 177 PIC18F1220/1320 REGISTER 19-8: CONFIG6L: CONFIGURATION REGISTER 6 LOW (BYTE ADDRESS 30000Ah) REGISTER 19-9: CONFIG6H: CONFIGURATION REGISTER 6 HIGH (BYTE ADDRESS 30000Bh) U-0 U-0 U-0 U-0 U-0 U-0 R/P-1 R/P-1 — — — — — — WRT1 WRT0 bit 7 bit 0 bit 7-2 Unimplemented: Read as ‘0’ bit 1 WRT1: Write Protection bit (PIC18F1320) 1 = Block 1 (001000-001FFFh) not write-protected 0 = Block 1 (001000-001FFFh) write-protected bit 0 WRT0: Write Protection bit (PIC18F1320) 1 = Block 0 (00200-000FFFh) not write-protected 0 = Block 0 (00200-000FFFh) write-protected bit 1 WRT1: Write Protection bit (PIC18F1220) 1 = Block 1 (000800-000FFFh) not write-protected 0 = Block 1 (000800-000FFFh) write-protected bit 0 WRT0: Write Protection bit (PIC18F1220) 1 = Block 0 (000200-0007FFh) not write-protected 0 = Block 0 (000200-0007FFh) write-protected Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state R/P-1 R/P-1 R-1 U-0 U-0 U-0 U-0 U-0 WRTD WRTB WRTC — — — — — bit 7 bit 0 bit 7 WRTD: Data EEPROM Write Protection bit 1 = Data EEPROM not write-protected 0 = Data EEPROM write-protected bit 6 WRTB: Boot Block Write Protection bit 1 = Boot Block (000000-0001FFh) not write-protected 0 = Boot Block (000000-0001FFh) write-protected bit 5 WRTC: Configuration Register Write Protection bit 1 = Configuration registers (300000-3000FFh) not write-protected 0 = Configuration registers (300000-3000FFh) write-protected Note: This bit is read-only in normal execution mode; it can be written only in Program mode. bit 4-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed statePIC18F1220/1320 DS39605F-page 178 © 2007 Microchip Technology Inc. REGISTER 19-10: CONFIG7L: CONFIGURATION REGISTER 7 LOW (BYTE ADDRESS 30000Ch) REGISTER 19-11: CONFIG7H: CONFIGURATION REGISTER 7 HIGH (BYTE ADDRESS 30000Dh) U-0 U-0 U-0 U-0 U-0 U-0 R/P-1 R/P-1 — — — — — — EBTR1 EBTR0 bit 7 bit 0 bit 7-2 Unimplemented: Read as ‘0’ bit 1 EBTR1: Table Read Protection bit (PIC18F1320) 1 = Block 1 (001000-001FFFh) not protected from table reads executed in other blocks 0 = Block 1 (001000-001FFFh) protected from table reads executed in other blocks bit 0 EBTR0: Table Read Protection bit (PIC18F1320) 1 = Block 0 (00200-000FFFh) not protected from table reads executed in other blocks 0 = Block 0 (00200-000FFFh) protected from table reads executed in other blocks bit 1 EBTR1: Table Read Protection bit (PIC18F1220) 1 = Block 1 (000800-000FFFh) not protected from table reads executed in other blocks 0 = Block 1 (000800-000FFFh) protected from table reads executed in other blocks bit 0 EBTR0: Table Read Protection bit (PIC18F1220) 1 = Block 0 (000200-0007FFh) not protected from table reads executed in other blocks 0 = Block 0 (000200-0007FFh) protected from table reads executed in other blocks Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state U-0 R/P-1 U-0 U-0 U-0 U-0 U-0 U-0 — EBTRB — — — — — — bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 EBTRB: Boot Block Table Read Protection bit 1 = Boot Block (000000-0001FFh) not protected from table reads executed in other blocks 0 = Boot Block (000000-0001FFh) protected from table reads executed in other blocks bit 5-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state© 2007 Microchip Technology Inc. DS39605F-page 179 PIC18F1220/1320 REGISTER 19-12: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F1220/1320 DEVICES REGISTER 19-13: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F1220/1320 DEVICES RRRRRRRR DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 bit 7 bit 0 bit 7-5 DEV2:DEV0: Device ID bits 111 = PIC18F1220 110 = PIC18F1320 bit 4-0 REV4:REV0: Revision ID bits These bits are used to indicate the device revision. Legend: R = Read-only bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state RRRRRRRR DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 bit 7 bit 0 bit 7-0 DEV10:DEV3: Device ID bits These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the part number. 0000 0111 = PIC18F1220/1320 devices Note: These values for DEV10:DEV3 may be shared with other devices. The specific device is always identified by using the entire DEV10:DEV0 bit sequence. Legend: R = Read-only bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed statePIC18F1220/1320 DS39605F-page 180 © 2007 Microchip Technology Inc. 19.2 Watchdog Timer (WDT) For PIC18F1220/1320 devices, the WDT is driven by the INTRC source. When the WDT is enabled, the clock source is also enabled. The nominal WDT period is 4 ms and has the same stability as the INTRC oscillator. The 4 ms period of the WDT is multiplied by a 16-bit postscaler. Any output of the WDT postscaler is selected by a multiplexer, controlled by bits in Configuration Register 2H. Available periods range from 4 ms to 131.072 seconds (2.18 minutes). The WDT and postscaler are cleared when any of the following events occur: execute a SLEEP or CLRWDT instruction, the IRCF bits (OSCCON<6:4>) are changed or a clock failure has occurred. Adjustments to the internal oscillator clock period using the OSCTUNE register also affect the period of the WDT by the same factor. For example, if the INTRC period is increased by 3%, then the WDT period is increased by 3%. 19.2.1 CONTROL REGISTER Register 19-14 shows the WDTCON register. This is a readable and writable register, which contains a control bit that allows software to override the WDT enable configuration bit, only if the configuration bit has disabled the WDT. FIGURE 19-1: WDT BLOCK DIAGRAM REGISTER 19-14: WDTCON REGISTER Note 1: The CLRWDT and SLEEP instructions clear the WDT and postscaler counts when executed. 2: Changing the setting of the IRCF bits (OSCCON<6:4>) clears the WDT and postscaler counts. 3: When a CLRWDT instruction is executed the postscaler count will be cleared. U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 — — — — — — — SWDTEN bit 7 bit 0 bit 7-1 Unimplemented: Read as ‘0’ bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit 1 = Watchdog Timer is on 0 = Watchdog Timer is off Note: This bit has no effect if the configuration bit, WDTEN (CONFIG2H<0>), is enabled. Legend: R = Readable bit W = Writable bit -n = Value at POR U = Unimplemented bit, read as ‘0’ INTRC Oscillator WDT Wake-up Reset WDT WDT Counter (31 kHz) Programmable Postscaler 1:1 to 1:32,768 Enable WDT WDTPS<3:0> SWDTEN WDTEN CLRWDT 4 from Sleep Reset All Device Sleep INTRC Control Resets ÷125© 2007 Microchip Technology Inc. DS39605F-page 181 PIC18F1220/1320 TABLE 19-2: SUMMARY OF WATCHDOG TIMER REGISTERS 19.3 Two-Speed Start-up The Two-Speed Start-up feature helps to minimize the latency period from oscillator start-up to code execution by allowing the microcontroller to use the INTRC oscillator as a clock source until the primary clock source is available. It is enabled by setting the IESO bit in Configuration Register 1H (CONFIG1H<7>). Two-Speed Start-up is available only if the primary oscillator mode is LP, XT, HS or HSPLL (crystal-based modes). Other sources do not require an OST start-up delay; for these, Two-Speed Start-up is disabled. When enabled, Resets and wake-ups from Sleep mode cause the device to configure itself to run from the internal oscillator block as the clock source, following the time-out of the Power-up Timer after a Power-on Reset is enabled. This allows almost immediate code execution while the primary oscillator starts and the OST is running. Once the OST times out, the device automatically switches to PRI_RUN mode. Because the OSCCON register is cleared on Reset events, the INTOSC (or postscaler) clock source is not initially available after a Reset event; the INTRC clock is used directly at its base frequency. To use a higher clock speed on wake-up, the INTOSC or postscaler clock sources can be selected to provide a higher clock speed by setting bits, IFRC2:IFRC0, immediately after Reset. For wake-ups from Sleep, the INTOSC or postscaler clock sources can be selected by setting IFRC2:IFRC0 prior to entering Sleep mode. In all other power managed modes, Two-Speed Start-up is not used. The device will be clocked by the currently selected clock source until the primary clock source becomes available. The setting of the IESO bit is ignored. 19.3.1 SPECIAL CONSIDERATIONS FOR USING TWO-SPEED START-UP While using the INTRC oscillator in Two-Speed Startup, the device still obeys the normal command sequences for entering power managed modes, including serial SLEEP instructions (refer to Section 3.1.3 “Multiple Sleep Commands”). In practice, this means that user code can change the SCS1:SCS0 bit settings and issue SLEEP commands before the OST times out. This would allow an application to briefly wake-up, perform routine “housekeeping” tasks and return to Sleep before the device starts to operate from the primary oscillator. User code can also check if the primary clock source is currently providing the system clocking by checking the status of the OSTS bit (OSCCON<3>). If the bit is set, the primary oscillator is providing the system clock. Otherwise, the internal oscillator block is providing the clock during wake-up from Reset or Sleep mode. FIGURE 19-2: TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL) Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 CONFIG2H — — — WDTPS3 WDTPS2 WDTPS2 WDTPS0 WDTEN RCON IPEN — — RI TO PD POR BOR WDTCON — — — — — — — SWDTEN Legend: Shaded cells are not used by the Watchdog Timer. Q1 Q3 Q4 OSC1 Peripheral Program PC PC + 2 INTOSC PLL Clock Q1 PC + 6 Q2 Output Q3 Q4 Q1 CPU Clock PC + 4 Clock Counter Q2 Q2 Q3 Q4 Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. Wake from Interrupt Event TPLL(1) 12345678 Clock Transition OSTS bit Set Multiplexer TOST(1)PIC18F1220/1320 DS39605F-page 182 © 2007 Microchip Technology Inc. 19.4 Fail-Safe Clock Monitor The Fail-Safe Clock Monitor (FSCM) allows the microcontroller to continue operation, in the event of an external oscillator failure, by automatically switching the system clock to the internal oscillator block. The FSCM function is enabled by setting the Fail-Safe Clock Monitor Enable bit, FSCM (CONFIG1H<6>). When FSCM is enabled, the INTRC oscillator runs at all times to monitor clocks to peripherals and provide an instant backup clock in the event of a clock failure. Clock monitoring (shown in Figure 19-3) is accomplished by creating a sample clock signal, which is the INTRC output divided by 64. This allows ample time between FSCM sample clocks for a peripheral clock edge to occur. The peripheral system clock and the sample clock are presented as inputs to the Clock Monitor latch (CM). The CM is set on the falling edge of the system clock source, but cleared on the rising edge of the sample clock. FIGURE 19-3: FSCM BLOCK DIAGRAM Clock failure is tested for on the falling edge of the sample clock. If a sample clock falling edge occurs while CM is still set, a clock failure has been detected (Figure 19-4). This causes the following: • the FSCM generates an oscillator fail interrupt by setting bit, OSCFIF (PIR2<7>); • the system clock source is switched to the internal oscillator block (OSCCON is not updated to show the current clock source – this is the Fail-Safe condition); and • the WDT is reset. Since the postscaler frequency from the internal oscillator block may not be sufficiently stable, it may be desirable to select another clock configuration and enter an alternate power managed mode (see Section 19.3.1 “Special Considerations for Using Two-Speed Start-up” and Section 3.1.3 “Multiple Sleep Commands” for more details). This can be done to attempt a partial recovery, or execute a controlled shutdown. To use a higher clock speed on wake-up, the INTOSC or postscaler clock sources can be selected to provide a higher clock speed by setting bits, IFRC2:IFRC0, immediately after Reset. For wake-ups from Sleep, the INTOSC or postscaler clock sources can be selected by setting IFRC2:IFRC0 prior to entering Sleep mode. Adjustments to the internal oscillator block, using the OSCTUNE register, also affect the period of the FSCM by the same factor. This can usually be neglected, as the clock frequency being monitored is generally much higher than the sample clock frequency. The FSCM will detect failures of the primary or secondary clock sources only. If the internal oscillator block fails, no failure would be detected, nor would any action be possible. 19.4.1 FSCM AND THE WATCHDOG TIMER Both the FSCM and the WDT are clocked by the INTRC oscillator. Since the WDT operates with a separate divider and counter, disabling the WDT has no effect on the operation of the INTRC oscillator when the FSCM is enabled. As already noted, the clock source is switched to the INTOSC clock when a clock failure is detected. Depending on the frequency selected by the IRCF2:IRCF0 bits, this may mean a substantial change in the speed of code execution. If the WDT is enabled with a small prescale value, a decrease in clock speed allows a WDT time-out to occur and a subsequent device Reset. For this reason, Fail-Safe Clock events also reset the WDT and postscaler, allowing it to start timing from when execution speed was changed and decreasing the likelihood of an erroneous time-out. Peripheral INTRC ÷ 64 S C Q (32 μs) 488 Hz (2.048 ms) Clock Monitor Latch (CM) (edge-triggered) Clock Failure Detected Source Clock Q© 2007 Microchip Technology Inc. DS39605F-page 183 PIC18F1220/1320 19.4.2 EXITING FAIL-SAFE OPERATION The Fail-Safe condition is terminated by either a device Reset, or by entering a power managed mode. On Reset, the controller starts the primary clock source specified in Configuration Register 1H (with any required start-up delays that are required for the oscillator mode, such as OST or PLL timer). The INTOSC multiplexer provides the system clock until the primary clock source becomes ready (similar to a TwoSpeed Start-up). The clock system source is then switched to the primary clock (indicated by the OSTS bit in the OSCCON register becoming set). The FailSafe Clock Monitor then resumes monitoring the peripheral clock. The primary clock source may never become ready during start-up. In this case, operation is clocked by the INTOSC multiplexer. The OSCCON register will remain in its Reset state until a power managed mode is entered. Entering a power managed mode by loading the OSCCON register and executing a SLEEP instruction will clear the Fail-Safe condition. When the Fail-Safe condition is cleared, the clock monitor will resume monitoring the peripheral clock. 19.4.3 FSCM INTERRUPTS IN POWER MANAGED MODES As previously mentioned, entering a power managed mode clears the Fail-Safe condition. By entering a power managed mode, the clock multiplexer selects the clock source selected by the OSCCON register. Fail-Safe monitoring of the power managed clock source resumes in the power managed mode. If an oscillator failure occurs during power managed operation, the subsequent events depend on whether or not the oscillator failure interrupt is enabled. If enabled (OSCFIF = 1), code execution will be clocked by the INTOSC multiplexer. An automatic transition back to the failed clock source will not occur. If the interrupt is disabled, the device will not exit the power managed mode on oscillator failure. Instead, the device will continue to operate as before, but clocked by the INTOSC multiplexer. While in Idle mode, subsequent interrupts will cause the CPU to begin executing instructions while being clocked by the INTOSC multiplexer. The device will not transition to a different clock source until the Fail-Safe condition is cleared. FIGURE 19-4: FSCM TIMING DIAGRAM OSCFIF CM Output System Clock Output Sample Clock Failure Detected Oscillator Failure Note: The system clock is normally at a much higher frequency than the sample clock. The relative frequencies in this example have been chosen for clarity. (Q) CM Test CM Test CM TestPIC18F1220/1320 DS39605F-page 184 © 2007 Microchip Technology Inc. 19.4.4 POR OR WAKE FROM SLEEP The FSCM is designed to detect oscillator failure at any point after the device has exited Power-on Reset (POR) or Low-Power Sleep mode. When the primary system clock is EC, RC or INTRC modes, monitoring can begin immediately following these events. For oscillator modes involving a crystal or resonator (HS, HSPLL, LP or XT), the situation is somewhat different. Since the oscillator may require a start-up time considerably longer than the FCSM sample clock time, a false clock failure may be detected. To prevent this, the internal oscillator block is automatically configured as the system clock and functions until the primary clock is stable (the OST and PLL timers have timed out). This is identical to Two-Speed Start-up mode. Once the primary clock is stable, the INTRC returns to its role as the FSCM source As noted in Section 19.3.1 “Special Considerations for Using Two-Speed Start-up”, it is also possible to select another clock configuration and enter an alternate power managed mode while waiting for the primary system clock to become stable. When the new powered managed mode is selected, the primary clock is disabled. Note: The same logic that prevents false oscillator failure interrupts on POR or wake from Sleep will also prevent the detection of the oscillator’s failure to start at all following these events. This can be avoided by monitoring the OSTS bit and using a timing routine to determine if the oscillator is taking too long to start. Even so, no oscillator failure interrupt will be flagged. © 2007 Microchip Technology Inc. DS39605F-page 185 PIC18F1220/1320 19.5 Program Verification and Code Protection The overall structure of the code protection on the PIC18 Flash devices differs significantly from other PIC devices. The user program memory is divided into three blocks. One of these is a boot block of 512 bytes. The remainder of the memory is divided into two blocks on binary boundaries. Each of the three blocks has three protection bits associated with them. They are: • Code-Protect bit (CPn) • Write-Protect bit (WRTn) • External Block Table Read bit (EBTRn) Figure 19-5 shows the program memory organization for 4 and 8-Kbyte devices and the specific code protection bit associated with each block. The actual locations of the bits are summarized in Table 19-3. FIGURE 19-5: CODE-PROTECTED PROGRAM MEMORY FOR PIC18F1220/1320 TABLE 19-3: SUMMARY OF CODE PROTECTION REGISTERS Block Code Protection Controlled By: MEMORY SIZE/DEVICE Block Code Protection Controlled By: Address Range 4 Kbytes (PIC18F1220) 8 Kbytes (PIC18F1320) Address Range CPB, WRTB, EBTRB 000000h 0001FFh Boot Block Boot Block 000000h 0001FFh CPB, WRTB, EBTRB CP0, WRT0, EBTR0 000200h 0007FFh Block 0 Block 0 000200h CP0, WRT0, EBTR0 CP1, WRT1, EBTR1 000800h 000FFFh Block 1 000FFFh (Unimplemented Memory Space) 001000h Unimplemented Read ‘0’s Block 1 001000h CP1, WRT1, EBTR1 001FFFh 1FFFFFh Unimplemented Read ‘0’s 002000h 1FFFFFh (Unimplemented Memory Space) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 300008h CONFIG5L — — — — — — CP1 CP0 300009h CONFIG5H CPD CPB — — — — — — 30000Ah CONFIG6L — — — — — — WRT1 WRT0 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 30000Ch CONFIG7L — — — — — — EBTR1 EBTR0 30000Dh CONFIG7H — EBTRB — — — — — — Legend: Shaded cells are unimplemented.PIC18F1220/1320 DS39605F-page 186 © 2007 Microchip Technology Inc. 19.5.1 PROGRAM MEMORY CODE PROTECTION The program memory may be read to, or written from, any location using the table read and table write instructions. The device ID may be read with table reads. The configuration registers may be read and written with the table read and table write instructions. In normal execution mode, the CPn bits have no direct effect. CPn bits inhibit external reads and writes. A block of user memory may be protected from table writes if the WRTn configuration bit is ‘0’. The EBTRn bits control table reads. For a block of user memory with the EBTRn bit set to ‘0’, a table read instruction that executes from within that block is allowed to read. A table read instruction that executes from a location outside of that block is not allowed to read and will result in reading ‘0’s. Figures 19-6 through 19-8 illustrate table write and table read protection. FIGURE 19-6: TABLE WRITE (WRTn) DISALLOWED: PIC18F1320 Note: Code protection bits may only be written to a ‘0’ from a ‘1’ state. It is not possible to write a ‘1’ to a bit in the ‘0’ state. Code protection bits are only set to ‘1’ by a full Chip Erase or Block Erase function. The full Chip Erase and Block Erase functions can only be initiated via ICSP or an external programmer. 000000h 0001FFh 000200h 000FFFh 001000h 001FFFh WRTB, EBTRB = 11 WRT0, EBTR0 = 01 TBLWT * TBLPTR = 0002FFh PC = 0007FEh PC = 0017FEh TBLWT * Register Values Program Memory Configuration Bit Settings Results: All table writes disabled to Blockn whenever WRTn = 0. WRT1, EBTR1 = 11© 2007 Microchip Technology Inc. DS39605F-page 187 PIC18F1220/1320 FIGURE 19-7: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED: PIC18F1320 FIGURE 19-8: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED: PIC18F1320 000000h 0001FFh 000200h 000FFFh 001000h 001FFFh WRTB, EBTRB = 11 WRT0, EBTR0 = 10 WRT1, EBTR1 = 11 TBLPTR = 0002FFh Register Values Program Memory Configuration Bit Settings PC = 001FFEh TBLRD * Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0. TABLAT register returns a value of ‘0’. 000000h 0001FFh 000200h 000FFFh 001000h 001FFFh WRTB, EBTRB = 11 WRT0, EBTR0 = 10 WRT1, EBTR1 = 11 TBLRD * TBLPTR = 0002FFh PC = 0007FEh Register Values Program Memory Configuration Bit Settings Results: Table reads permitted within Blockn, even when EBTRBn = 0. TABLAT register returns the value of the data at the location TBLPTR.PIC18F1220/1320 DS39605F-page 188 © 2007 Microchip Technology Inc. 19.5.2 DATA EEPROM CODE PROTECTION The entire data EEPROM is protected from external reads and writes by two bits: CPD and WRTD. CPD inhibits external reads and writes of data EEPROM. WRTD inhibits external writes to data EEPROM. The CPU can continue to read and write data EEPROM, regardless of the protection bit settings. 19.5.3 CONFIGURATION REGISTER PROTECTION The configuration registers can be write-protected. The WRTC bit controls protection of the configuration registers. In normal execution mode, the WRTC bit is readable only. WRTC can only be written via ICSP or an external programmer. 19.6 ID Locations Eight memory locations (200000h-200007h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are both readable and writable during normal execution through the TBLRD and TBLWT instructions, or during program/verify. The ID locations can be read when the device is code-protected. 19.7 In-Circuit Serial Programming PIC18F1220/1320 microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed (see Table 19-4). 19.8 In-Circuit Debugger When the DEBUG bit in configuration register, CONFIG4L, is programmed to a ‘0’, the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB® IDE. When the microcontroller has this feature enabled, some resources are not available for general use. Table 19-5 shows which resources are required by the background debugger. TABLE 19-5: DEBUGGER RESOURCES To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to MCLR/VPP, VDD, VSS, RB7 and RB6. This will interface to the In-Circuit Debugger module available from Microchip, or one of the third party development tool companies (see the note following Section 19.7 “In-Circuit Serial Programming” for more information). Note: The Timer1 oscillator shares the T1OSI and T1OSO pins with the PGD and PGC pins used for programming and debugging. When using the Timer1 oscillator, In-Circuit Serial Programming (ICSP) may not function correctly (high voltage or low voltage), or the In-Circuit Debugger (ICD) may not communicate with the controller. As a result of using either ICSP or ICD, the Timer1 crystal may be damaged. If ICSP or ICD operations are required, the crystal should be disconnected from the circuit (disconnect either lead), or installed after programming. The oscillator loading capacitors may remain in-circuit during ICSP or ICD operation. TABLE 19-4: ICSP/ICD CONNECTIONS Signal Pin Notes PGD RB7/PGD/T1OSI/ P1D/KBI3 Shared with T1OSC – protect crystal PGC RB6/PGC/T1OSO/ T13CKI/P1C/KBI2 Shared with T1OSC – protect crystal MCLR MCLR/VPP/RA5 VDD VDD VSS VSS PGM RB5/PGM/KBI1 Optional – pull RB5 low is LVP enabled I/O pins: RB6, RB7 Stack: 2 levels Program Memory: 512 bytes Data Memory: 10 bytes© 2007 Microchip Technology Inc. DS39605F-page 189 PIC18F1220/1320 19.9 Low-Voltage ICSP Programming The LVP bit in configuration register, CONFIG4L, enables Low-Voltage Programming (LVP). When LVP is enabled, the microcontroller can be programmed without requiring high voltage being applied to the MCLR/VPP/RA5 pin, but the RB5/PGM/KBI1 pin is then dedicated to controlling Program mode entry and is not available as a general purpose I/O pin. LVP is enabled in erased devices. While programming using LVP, VDD is applied to the MCLR/VPP/RA5 pin as in normal execution mode. To enter Programming mode, VDD is applied to the PGM pin. If Low-Voltage Programming mode will not be used, the LVP bit can be cleared and RB5/PGM/KBI1 becomes available as the digital I/O pin RB5. The LVP bit may be set or cleared only when using standard high-voltage programming (VIHH applied to the MCLR/VPP/RA5 pin). Once LVP has been disabled, only the standard highvoltage programming is available and must be used to program the device. Memory that is not code-protected can be erased, using either a Block Erase, or erased row by row, then written at any specified VDD. If code-protected memory is to be erased, a Block Erase is required. If a Block Erase is to be performed when using Low-Voltage Programming, the device must be supplied with VDD of 4.5V to 5.5V. Note 1: High-voltage programming is always available, regardless of the state of the LVP bit or the PGM pin, by applying VIHH to the MCLR pin. 2: When Low-Voltage Programming is enabled, the RB5 pin can no longer be used as a general purpose I/O pin. 3: When LVP is enabled, externally pull the PGM pin to VSS to allow normal program execution.PIC18F1220/1320 DS39605F-page 190 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 191 PIC18F1220/1320 20.0 INSTRUCTION SET SUMMARY The PIC18 instruction set adds many enhancements to the previous PIC instruction sets, while maintaining an easy migration from these PIC instruction sets. Most instructions are a single program memory word (16 bits), but there are three instructions that require two program memory locations. Each single-word instruction is a 16-bit word divided into an opcode, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. The instruction set is highly orthogonal and is grouped into four basic categories: • Byte-oriented operations • Bit-oriented operations • Literal operations • Control operations The PIC18 instruction set summary in Table 20-1 lists byte-oriented, bit-oriented, literal and control operations. Table 20-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. The file register (specified by ‘f’) 2. The destination of the result (specified by ‘d’) 3. The accessed memory (specified by ‘a’) The file register designator ‘f’ specifies which file register is to be used by the instruction. The destination designator ‘d’ specifies where the result of the operation is to be placed. If ‘d’ is zero, the result is placed in the WREG register. If ‘d’ is one, the result is placed in the file register specified in the instruction. All bit-oriented instructions have three operands: 1. The file register (specified by ‘f’) 2. The bit in the file register (specified by ‘b’) 3. The accessed memory (specified by ‘a’) The bit field designator ‘b’ selects the number of the bit affected by the operation, while the file register designator ‘f’ represents the number of the file in which the bit is located. The literal instructions may use some of the following operands: • A literal value to be loaded into a file register (specified by ‘k’) • The desired FSR register to load the literal value into (specified by ‘f’) • No operand required (specified by ‘—’) The control instructions may use some of the following operands: • A program memory address (specified by ‘n’) • The mode of the CALL or RETURN instructions (specified by ‘s’) • The mode of the table read and table write instructions (specified by ‘m’) • No operand required (specified by ‘—’) All instructions are a single word, except for three double-word instructions. These three instructions were made double-word instructions so that all the required information is available in these 32 bits. In the second word, the 4 MSbs are ‘1’s. If this second word is executed as an instruction (by itself), it will execute as a NOP. All single-word instructions are executed in a single instruction cycle, unless a conditional test is true, or the program counter is changed as a result of the instruction. In these cases, the execution takes two instruction cycles, with the additional instruction cycle(s) executed as a NOP. The double-word instructions execute in two instruction cycles. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 μs. If a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 μs. Two-word branch instructions (if true) would take 3 μs. Figure 20-1 shows the general formats that the instructions can have. All examples use the format ‘nnh’ to represent a hexadecimal number, where ‘h’ signifies a hexadecimal digit. The Instruction Set Summary, shown in Table 20-1, lists the instructions recognized by the Microchip Assembler (MPASMTM). Section 20.2 “Instruction Set” provides a description of each instruction. 20.1 Read-Modify-Write Operations Any instruction that specifies a file register as part of the instruction performs a Read-Modify-Write (R-M-W) operation. The register is read, the data is modified and the result is stored according to either the instruction or the destination designator ‘d’. A read operation is performed on a register even if the instruction writes to that register. For example, a “BCF PORTB,1” instruction will read PORTB, clear bit 1 of the data, then write the result back to PORTB. The read operation would have the unintended result that any condition that sets the RBIF flag would be cleared. The R-M-W operation may also copy the level of an input pin to its corresponding output latch.PIC18F1220/1320 DS39605F-page 192 © 2007 Microchip Technology Inc. TABLE 20-1: OPCODE FIELD DESCRIPTIONS Field Description a RAM access bit a = 0: RAM location in Access RAM (BSR register is ignored) a = 1: RAM bank is specified by BSR register bbb Bit address within an 8-bit file register (0 to 7). BSR Bank Select Register. Used to select the current RAM bank. d Destination select bit d = 0: store result in WREG d = 1: store result in file register f dest Destination either the WREG register or the specified register file location. f 8-bit register file address (0x00 to 0xFF). fs 12-bit register file address (0x000 to 0xFFF). This is the source address. fd 12-bit register file address (0x000 to 0xFFF). This is the destination address. k Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value). label Label name. mm The mode of the TBLPTR register for the table read and table write instructions. Only used with table read and table write instructions: * No change to register (such as TBLPTR with table reads and writes) *+ Post-Increment register (such as TBLPTR with table reads and writes) *- Post-Decrement register (such as TBLPTR with table reads and writes) +* Pre-Increment register (such as TBLPTR with table reads and writes) n The relative address (2’s complement number) for relative branch instructions, or the direct address for call/branch and return instructions. PRODH Product of Multiply High Byte. PRODL Product of Multiply Low Byte. s Fast Call/Return mode select bit s = 0: do not update into/from shadow registers s = 1: certain registers loaded into/from shadow registers (Fast mode) u Unused or unchanged. WREG Working register (accumulator). x Don’t care (‘0’ or ‘1’). The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. TBLPTR 21-bit Table Pointer (points to a program memory location). TABLAT 8-bit Table Latch. TOS Top-of-Stack. PC Program Counter. PCL Program Counter Low Byte. PCH Program Counter High Byte. PCLATH Program Counter High Byte Latch. PCLATU Program Counter Upper Byte Latch. GIE Global Interrupt Enable bit. WDT Watchdog Timer. TO Time-out bit. PD Power-down bit. C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative. [ ] Optional. ( ) Contents. → Assigned to. < > Register bit field. ∈ In the set of. italics User defined term (font is Courier).© 2007 Microchip Technology Inc. DS39605F-page 193 PIC18F1220/1320 FIGURE 20-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 15 10 9 8 7 0 d = 0 for result destination to be WREG register OPCODE d a f (FILE #) d = 1 for result destination to be file register (f) a = 0 to force Access Bank Bit-oriented file register operations 15 12 11 9 8 7 0 OPCODE b (BIT #) a f (FILE #) b = 3-bit position of bit in file register (f) Literal operations 15 8 7 0 OPCODE k (literal) k = 8-bit immediate value Byte to Byte move operations (2-word) 15 12 11 0 OPCODE f (Source FILE #) CALL, GOTO and Branch operations 15 8 7 0 OPCODE n<7:0> (literal) n = 20-bit immediate value a = 1 for BSR to select bank f = 8-bit file register address a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address 15 12 11 0 1111 n<19:8> (literal) 15 12 11 0 1111 f (Destination FILE #) f = 12-bit file register address Control operations Example Instruction ADDWF MYREG, W, B MOVFF MYREG1, MYREG2 BSF MYREG, bit, B MOVLW 0x7F GOTO Label 15 8 7 0 OPCODE n<7:0> (literal) 15 12 11 0 n<19:8> (literal) CALL MYFUNC 15 11 10 0 OPCODE n<10:0> (literal) S = Fast bit BRA MYFUNC 15 8 7 0 OPCODE n<7:0> (literal) BC MYFUNC SPIC18F1220/1320 DS39605F-page 194 © 2007 Microchip Technology Inc. TABLE 20-1: PIC18FXXXX INSTRUCTION SET Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB SUBWF SUBWFB SWAPF TSTFSZ XORWF f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a fs, fd f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a Add WREG and f Add WREG and Carry bit to f AND WREG with f Clear f Complement f Compare f with WREG, skip = Compare f with WREG, skip > Compare f with WREG, skip < Decrement f Decrement f, Skip if 0 Decrement f, Skip if Not 0 Increment f Increment f, Skip if 0 Increment f, Skip if Not 0 Inclusive OR WREG with f Move f Move fs (source) to 1st word fd (destination) 2nd word Move WREG to f Multiply WREG with f Negate f Rotate Left f through Carry Rotate Left f (No Carry) Rotate Right f through Carry Rotate Right f (No Carry) Set f Subtract f from WREG with borrow Subtract WREG from f Subtract WREG from f with borrow Swap nibbles in f Test f, skip if 0 Exclusive OR WREG with f 1 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 (2 or 3) 1 0010 0010 0001 0110 0001 0110 0110 0110 0000 0010 0100 0010 0011 0100 0001 0101 1100 1111 0110 0000 0110 0011 0100 0011 0100 0110 0101 0101 0101 0011 0110 0001 01da 00da 01da 101a 11da 001a 010a 000a 01da 11da 11da 10da 11da 10da 00da 00da ffff ffff 111a 001a 110a 01da 01da 00da 00da 100a 01da 11da 10da 10da 011a 10da ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None None None C, DC, Z, OV, N C, Z, N Z, N C, Z, N Z, N None C, DC, Z, OV, N C, DC, Z, OV, N C, DC, Z, OV, N None None Z, N 1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1 1, 2 1, 2 1, 2 1, 2 4 1, 2 BIT-ORIENTED FILE REGISTER OPERATIONS BCF BSF BTFSC BTFSS BTG f, b, a f, b, a f, b, a f, b, a f, d, a Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set Bit Toggle f 1 1 1 (2 or 3) 1 (2 or 3) 1 1001 1000 1011 1010 0111 bbba bbba bbba bbba bbba ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff None None None None None 1, 2 1, 2 3, 4 3, 4 1, 2 Note 1: When a Port register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’. 2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction. 5: If the table write starts the write cycle to internal memory, the write will continue until terminated.© 2007 Microchip Technology Inc. DS39605F-page 195 PIC18F1220/1320 CONTROL OPERATIONS BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL CLRWDT DAW GOTO NOP NOP POP PUSH RCALL RESET RETFIE RETLW RETURN SLEEP n n n n n n n n n n, s — — n — — — — n s k s — Branch if Carry Branch if Negative Branch if Not Carry Branch if Not Negative Branch if Not Overflow Branch if Not Zero Branch if Overflow Branch Unconditionally Branch if Zero Call subroutine 1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to address 1st word 2nd word No Operation No Operation Pop top of return stack (TOS) Push top of return stack (TOS) Relative Call Software device Reset Return from interrupt enable Return with literal in WREG Return from Subroutine Go into Standby mode 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 2 1 1 2 1 1 1 1 2 1 2 2 2 1 1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 0000 0000 0000 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 1100 0000 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 kkkk 0001 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s kkkk 001s 0011 None None None None None None None None None None TO, PD C None None None None None None All GIE/GIEH, PEIE/GIEL None None TO, PD 4 TABLE 20-1: PIC18FXXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb Note 1: When a Port register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’. 2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction. 5: If the table write starts the write cycle to internal memory, the write will continue until terminated.PIC18F1220/1320 DS39605F-page 196 © 2007 Microchip Technology Inc. LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR MOVLB MOVLW MULLW RETLW SUBLW XORLW k k k f, k k k k k k k Add literal and WREG AND literal with WREG Inclusive OR literal with WREG Move literal (12-bit) 2nd word to FSRx 1st word Move literal to BSR<3:0> Move literal to WREG Multiply literal with WREG Return with literal in WREG Subtract WREG from literal Exclusive OR literal with WREG 1 1 1 2 1 1 1 2 1 1 0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk C, DC, Z, OV, N Z, N Z, N None None None None None C, DC, Z, OV, N Z, N DATA MEMORY ↔ PROGRAM MEMORY OPERATIONS TBLRD* TBLRD*+ TBLRD*- TBLRD+* TBLWT* TBLWT*+ TBLWT*- TBLWT+* Table read Table read with post-increment Table read with post-decrement Table read with pre-increment Table write Table write with post-increment Table write with post-decrement Table write with pre-increment 2 2 (5) 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 1001 1010 1011 1100 1101 1110 1111 None None None None None None None None TABLE 20-1: PIC18FXXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb Note 1: When a Port register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’. 2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction. 5: If the table write starts the write cycle to internal memory, the write will continue until terminated.© 2007 Microchip Technology Inc. DS39605F-page 197 PIC18F1220/1320 20.2 Instruction Set ADDLW ADD literal to W Syntax: [ label ] ADDLW k Operands: 0 ≤ k ≤ 255 Operation: (W) + k → W Status Affected: N, OV, C, DC, Z Encoding: 0000 1111 kkkk kkkk Description: The contents of W are added to the 8-bit literal ‘k’ and the result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: ADDLW 0x15 Before Instruction W = 0x10 After Instruction W = 0x25 ADDWF ADD W to f Syntax: [ label ] ADDWF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) + (f) → dest Status Affected: N, OV, C, DC, Z Encoding: 0010 01da ffff ffff Description: Add W to register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected. If ‘a’ is ‘1’, the BSR is used. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ADDWF REG, W Before Instruction W = 0x17 REG = 0xC2 After Instruction W = 0xD9 REG = 0xC2PIC18F1220/1320 DS39605F-page 198 © 2007 Microchip Technology Inc. ADDWFC ADD W and Carry bit to f Syntax: [ label ] ADDWFC f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) + (f) + (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0010 00da ffff ffff Description: Add W, the Carry flag and data memory location ‘f’. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed in data memory location ‘f’. If ‘a’ is ‘0’, the Access Bank will be selected. If ‘a’ is ‘1’, the BSR will not be overridden. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ADDWFC REG, W Before Instruction Carry bit = 1 REG = 0x02 W = 0x4D After Instruction Carry bit = 0 REG = 0x02 W = 0x50 ANDLW AND literal with W Syntax: [ label ] ANDLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .AND. k → W Status Affected: N, Z Encoding: 0000 1011 kkkk kkkk Description: The contents of W are AND’ed with the 8-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: ANDLW 0x5F Before Instruction W = 0xA3 After Instruction W = 0x03© 2007 Microchip Technology Inc. DS39605F-page 199 PIC18F1220/1320 ANDWF AND W with f Syntax: [ label ] ANDWF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .AND. (f) → dest Status Affected: N, Z Encoding: 0001 01da ffff ffff Description: The contents of W are AND’ed with register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected. If ‘a’ is ‘1’, the BSR will not be overridden (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ANDWF REG, W Before Instruction W = 0x17 REG = 0xC2 After Instruction W = 0x02 REG = 0xC2 BC Branch if Carry Syntax: [ label ] BC n Operands: -128 ≤ n ≤ 127 Operation: if Carry bit is ‘1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0010 nnnn nnnn Description: If the Carry bit is ‘1’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BC JUMP Before Instruction PC = address (HERE) After Instruction If Carry = 1; PC = address (JUMP) If Carry = 0; PC = address (HERE + 2)PIC18F1220/1320 DS39605F-page 200 © 2007 Microchip Technology Inc. BCF Bit Clear f Syntax: [ label ] BCF f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: 0 → f Status Affected: None Encoding: 1001 bbba ffff ffff Description: Bit ‘b’ in register ‘f’ is cleared. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BCF FLAG_REG, 7 Before Instruction FLAG_REG = 0xC7 After Instruction FLAG_REG = 0x47 BN Branch if Negative Syntax: [ label ] BN n Operands: -128 ≤ n ≤ 127 Operation: if Negative bit is ‘1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0110 nnnn nnnn Description: If the Negative bit is ‘1’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BN Jump Before Instruction PC = address (HERE) After Instruction If Negative = 1; PC = address (Jump) If Negative = 0; PC = address (HERE + 2)© 2007 Microchip Technology Inc. DS39605F-page 201 PIC18F1220/1320 BNC Branch if Not Carry Syntax: [ label ] BNC n Operands: -128 ≤ n ≤ 127 Operation: if Carry bit is ‘0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0011 nnnn nnnn Description: If the Carry bit is ‘0’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNC Jump Before Instruction PC = address (HERE) After Instruction If Carry = 0; PC = address (Jump) If Carry = 1; PC = address (HERE + 2) BNN Branch if Not Negative Syntax: [ label ] BNN n Operands: -128 ≤ n ≤ 127 Operation: if Negative bit is ‘0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0111 nnnn nnnn Description: If the Negative bit is ‘0’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNN Jump Before Instruction PC = address (HERE) After Instruction If Negative = 0; PC = address (Jump) If Negative = 1; PC = address (HERE + 2)PIC18F1220/1320 DS39605F-page 202 © 2007 Microchip Technology Inc. BNOV Branch if Not Overflow Syntax: [ label ] BNOV n Operands: -128 ≤ n ≤ 127 Operation: if Overflow bit is ‘0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0101 nnnn nnnn Description: If the Overflow bit is ‘0’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNOV Jump Before Instruction PC = address (HERE) After Instruction If Overflow = 0; PC = address (Jump) If Overflow = 1; PC = address (HERE + 2) BNZ Branch if Not Zero Syntax: [ label ] BNZ n Operands: -128 ≤ n ≤ 127 Operation: if Zero bit is ‘0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0001 nnnn nnnn Description: If the Zero bit is ‘0’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNZ Jump Before Instruction PC = address (HERE) After Instruction If Zero = 0; PC = address (Jump) If Zero = 1; PC = address (HERE + 2)© 2007 Microchip Technology Inc. DS39605F-page 203 PIC18F1220/1320 BRA Unconditional Branch Syntax: [ label ] BRA n Operands: -1024 ≤ n ≤ 1023 Operation: (PC) + 2 + 2n → PC Status Affected: None Encoding: 1101 0nnn nnnn nnnn Description: Add the 2’s complement number ‘2n’ to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation Example: HERE BRA Jump Before Instruction PC = address (HERE) After Instruction PC = address (Jump) BSF Bit Set f Syntax: [ label ] BSF f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: 1 → f Status Affected: None Encoding: 1000 bbba ffff ffff Description: Bit ‘b’ in register ‘f’ is set. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BSF FLAG_REG, 7 Before Instruction FLAG_REG = 0x0A After Instruction FLAG_REG = 0x8APIC18F1220/1320 DS39605F-page 204 © 2007 Microchip Technology Inc. BTFSC Bit Test File, Skip if Clear Syntax: [ label ] BTFSC f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: skip if (f) = 0 Status Affected: None Encoding: 1011 bbba ffff ffff Description: If bit ‘b’ in register ‘f’ is ‘0’, then the next instruction is skipped. If bit ‘b’ is ‘0’, then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSC : : FLAG, 1 Before Instruction PC = address (HERE) After Instruction If FLAG<1> = 0; PC = address (TRUE) If FLAG<1> = 1; PC = address (FALSE) BTFSS Bit Test File, Skip if Set Syntax: [ label ] BTFSS f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b < 7 a ∈ [0,1] Operation: skip if (f) = 1 Status Affected: None Encoding: 1010 bbba ffff ffff Description: If bit ‘b’ in register ‘f’ is ‘1’, then the next instruction is skipped. If bit ‘b’ is ‘1’, then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSS : : FLAG, 1 Before Instruction PC = address (HERE) After Instruction If FLAG<1> = 0; PC = address (FALSE) If FLAG<1> = 1; PC = address (TRUE)© 2007 Microchip Technology Inc. DS39605F-page 205 PIC18F1220/1320 BTG Bit Toggle f Syntax: [ label ] BTG f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b < 7 a ∈ [0,1] Operation: (f) → f Status Affected: None Encoding: 0111 bbba ffff ffff Description: Bit ‘b’ in data memory location ‘f’ is inverted. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BTG PORTB, 4 Before Instruction: PORTB = 0111 0101 [0x75] After Instruction: PORTB = 0110 0101 [0x65] BOV Branch if Overflow Syntax: [ label ] BOV n Operands: -128 ≤ n ≤ 127 Operation: if Overflow bit is ‘1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0100 nnnn nnnn Description: If the Overflow bit is ‘1’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BOV JUMP Before Instruction PC = address (HERE) After Instruction If Overflow = 1; PC = address (JUMP) If Overflow = 0; PC = address (HERE + 2)PIC18F1220/1320 DS39605F-page 206 © 2007 Microchip Technology Inc. BZ Branch if Zero Syntax: [ label ] BZ n Operands: -128 ≤ n ≤ 127 Operation: if Zero bit is ‘1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0000 nnnn nnnn Description: If the Zero bit is ‘1’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BZ Jump Before Instruction PC = address (HERE) After Instruction If Zero = 1; PC = address (Jump) If Zero = 0; PC = address (HERE + 2) CALL Subroutine Call Syntax: [ label ] CALL k [,s] Operands: 0 ≤ k ≤ 1048575 s ∈ [0,1] Operation: (PC) + 4 → TOS, k → PC<20:1>, if s = 1 (W) → WS, (Status) → STATUSS, (BSR) → BSRS Status Affected: None Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 110s k19kkk k7kkk kkkk kkkk0 kkkk8 Description: Subroutine call of entire 2-Mbyte memory range. First, return address (PC + 4) is pushed onto the return stack. If ‘s’ = 1, the W, Status and BSR registers are also pushed into their respective shadow registers, WS, STATUSS and BSRS. If ‘s’ = 0, no update occurs (default). Then, the 20-bit value ‘k’ is loaded into PC<20:1>. CALL is a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’<7:0>, Push PC to stack Read literal ‘k’<19:8>, Write to PC No operation No operation No operation No operation Example: HERE CALL THERE, FAST Before Instruction PC = address (HERE) After Instruction PC = address (THERE) TOS = address (HERE + 4) WS = W BSRS = BSR STATUSS = Status© 2007 Microchip Technology Inc. DS39605F-page 207 PIC18F1220/1320 CLRF Clear f Syntax: [ label ] CLRF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: 000h → f 1 → Z Status Affected: Z Encoding: 0110 101a ffff ffff Description: Clears the contents of the specified register. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: CLRF FLAG_REG Before Instruction FLAG_REG = 0x5A After Instruction FLAG_REG = 0x00 CLRWDT Clear Watchdog Timer Syntax: [ label ] CLRWDT Operands: None Operation: 000h → WDT, 000h → WDT postscaler, 1 → TO, 1 → PD Status Affected: TO, PD Encoding: 0000 0000 0000 0100 Description: CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits, TO and PD, are set. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data No operation Example: CLRWDT Before Instruction WDT Counter = ? After Instruction WDT Counter = 0x00 WDT Postscaler = 0 TO = 1 PD = 1PIC18F1220/1320 DS39605F-page 208 © 2007 Microchip Technology Inc. COMF Complement f Syntax: [ label ] COMF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest Status Affected: N, Z Encoding: 0001 11da ffff ffff Description: The contents of register ‘f’ are complemented. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: COMF REG, W Before Instruction REG = 0x13 After Instruction REG = 0x13 W = 0xEC CPFSEQ Compare f with W, skip if f = W Syntax: [ label ] CPFSEQ f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) = (W) (unsigned comparison) Status Affected: None Encoding: 0110 001a ffff ffff Description: Compares the contents of data memory location ‘f’ to the contents of W by performing an unsigned subtraction. If ‘f’ = W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSEQ REG NEQUAL : EQUAL : Before Instruction PC Address = HERE W =? REG = ? After Instruction If REG = W; PC = Address (EQUAL) If REG ≠ W; PC = Address (NEQUAL)© 2007 Microchip Technology Inc. DS39605F-page 209 PIC18F1220/1320 CPFSGT Compare f with W, skip if f > W Syntax: [ label ] CPFSGT f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) > (W) (unsigned comparison) Status Affected: None Encoding: 0110 010a ffff ffff Description: Compares the contents of data memory location ‘f’ to the contents of W by performing an unsigned subtraction. If the contents of ‘f’ are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSGT REG NGREATER : GREATER : Before Instruction PC = Address (HERE) W = ? After Instruction If REG > W; PC = Address (GREATER) If REG ≤ W; PC = Address (NGREATER) CPFSLT Compare f with W, skip if f < W Syntax: [ label ] CPFSLT f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) < (W) (unsigned comparison) Status Affected: None Encoding: 0110 000a ffff ffff Description: Compares the contents of data memory location ‘f’ to the contents of W by performing an unsigned subtraction. If the contents of ‘f’ are less than the contents of W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected. If ‘a’ is ‘1’, the BSR will not be overridden (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSLT REG NLESS : LESS : Before Instruction PC = Address (HERE) W = ? After Instruction If REG < W; PC = Address (LESS) If REG ≥ W; PC = Address (NLESS)PIC18F1220/1320 DS39605F-page 210 © 2007 Microchip Technology Inc. DAW Decimal Adjust W Register Syntax: [ label ] DAW Operands: None Operation: If [W<3:0> > 9] or [DC = 1] then (W<3:0>) + 6 → W<3:0>; else (W<3:0>) → W<3:0>; If [W<7:4> > 9] or [C = 1] then (W<7:4>) + 6 → W<7:4>; else (W<7:4>) → W<7:4>; Status Affected: C, DC Encoding: 0000 0000 0000 0111 Description: DAW adjusts the eight-bit value in W, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. The Carry bit may be set by DAW regardless of its setting prior to the DAW instruction. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register W Process Data Write W Example 1: DAW Before Instruction W = 0xA5 C =0 DC = 0 After Instruction W = 0x05 C =1 DC = 0 Example 2: Before Instruction W = 0xCE C =0 DC = 0 After Instruction W = 0x34 C =1 DC = 0 DECF Decrement f Syntax: [ label ] DECF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest Status Affected: C, DC, N, OV, Z Encoding: 0000 01da ffff ffff Description: Decrement register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: DECF CNT Before Instruction CNT = 0x01 Z =0 After Instruction CNT = 0x00 Z =1© 2007 Microchip Technology Inc. DS39605F-page 211 PIC18F1220/1320 DECFSZ Decrement f, skip if 0 Syntax: [ label ] DECFSZ f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest, skip if result = 0 Status Affected: None Encoding: 0010 11da ffff ffff Description: The contents of register ‘f’ are decremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE DECFSZ CNT GOTO LOOP CONTINUE Before Instruction PC = Address (HERE) After Instruction CNT = CNT – 1 If CNT = 0; PC = Address (CONTINUE) If CNT ≠ 0; PC = Address (HERE + 2) DCFSNZ Decrement f, skip if not 0 Syntax: [ label ] DCFSNZ f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest, skip if result ≠ 0 Status Affected: None Encoding: 0100 11da ffff ffff Description: The contents of register ‘f’ are decremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is not ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a twocycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE DCFSNZ TEMP ZERO : NZERO : Before Instruction TEMP = ? After Instruction TEMP = TEMP – 1, If TEMP = 0; PC = Address (ZERO) If TEMP ≠ 0; PC = Address (NZERO)PIC18F1220/1320 DS39605F-page 212 © 2007 Microchip Technology Inc. GOTO Unconditional Branch Syntax: [ label ] GOTO k Operands: 0 ≤ k ≤ 1048575 Operation: k → PC<20:1> Status Affected: None Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8 Description: GOTO allows an unconditional branch anywhere within the entire 2-Mbyte memory range. The 20-bit value ‘k’ is loaded into PC<20:1>. GOTO is always a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’<7:0>, No operation Read literal ‘k’<19:8>, Write to PC No operation No operation No operation No operation Example: GOTO THERE After Instruction PC = Address (THERE) INCF Increment f Syntax: [ label ] INCF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest Status Affected: C, DC, N, OV, Z Encoding: 0010 10da ffff ffff Description: The contents of register ‘f’ are incremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: INCF CNT Before Instruction CNT = 0xFF Z =0 C =? DC = ? After Instruction CNT = 0x00 Z =1 C =1 DC = 1© 2007 Microchip Technology Inc. DS39605F-page 213 PIC18F1220/1320 INCFSZ Increment f, skip if 0 Syntax: [ label ] INCFSZ f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest, skip if result = 0 Status Affected: None Encoding: 0011 11da ffff ffff Description: The contents of register ‘f’ are incremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE INCFSZ CNT NZERO : ZERO : Before Instruction PC = Address (HERE) After Instruction CNT = CNT + 1 If CNT = 0; PC = Address (ZERO) If CNT ≠ 0; PC = Address (NZERO) INFSNZ Increment f, skip if not 0 Syntax: [ label ] INFSNZ f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest, skip if result ≠ 0 Status Affected: None Encoding: 0100 10da ffff ffff Description: The contents of register ‘f’ are incremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is not ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE INFSNZ REG ZERO NZERO Before Instruction PC = Address (HERE) After Instruction REG = REG + 1 If REG ≠ 0; PC = Address (NZERO) If REG = 0; PC = Address (ZERO)PIC18F1220/1320 DS39605F-page 214 © 2007 Microchip Technology Inc. IORLW Inclusive OR literal with W Syntax: [ label ] IORLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .OR. k → W Status Affected: N, Z Encoding: 0000 1001 kkkk kkkk Description: The contents of W are OR’ed with the eight-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: IORLW 0x35 Before Instruction W = 0x9A After Instruction W = 0xBF IORWF Inclusive OR W with f Syntax: [ label ] IORWF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .OR. (f) → dest Status Affected: N, Z Encoding: 0001 00da ffff ffff Description: Inclusive OR W with register ‘f’. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: IORWF RESULT, W Before Instruction RESULT = 0x13 W = 0x91 After Instruction RESULT = 0x13 W = 0x93© 2007 Microchip Technology Inc. DS39605F-page 215 PIC18F1220/1320 LFSR Load FSR Syntax: [ label ] LFSR f,k Operands: 0 ≤ f ≤ 2 0 ≤ k ≤ 4095 Operation: k → FSRf Status Affected: None Encoding: 1110 1111 1110 0000 00ff k7kkk k11kkk kkkk Description: The 12-bit literal ‘k’ is loaded into the file select register pointed to by ‘f’. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ MSB Process Data Write literal ‘k’ MSB to FSRfH Decode Read literal ‘k’ LSB Process Data Write literal ‘k’ to FSRfL Example: LFSR 2, 0x3AB After Instruction FSR2H = 0x03 FSR2L = 0xAB MOVF Move f Syntax: [ label ] MOVF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: f → dest Status Affected: N, Z Encoding: 0101 00da ffff ffff Description: The contents of register ‘f’ are moved to a destination dependent upon the status of ‘d’. If ‘d’ is ‘f’, the result is placed in W. If ‘d’ is ‘f’, the result is placed back in register ‘f’ (default). Location ‘f’ can be anywhere in the 256-byte bank. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write W Example: MOVF REG, W Before Instruction REG = 0x22 W = 0xFF After Instruction REG = 0x22 W = 0x22PIC18F1220/1320 DS39605F-page 216 © 2007 Microchip Technology Inc. MOVFF Move f to f Syntax: [ label ] MOVFF fs,fd Operands: 0 ≤ fs ≤ 4095 0 ≤ fd ≤ 4095 Operation: (fs) → fd Status Affected: None Encoding: 1st word (source) 2nd word (destin.) 1100 1111 ffff ffff ffff ffff ffffs ffffd Description: The contents of source register ‘fs’ are moved to destination register ‘fd’. Location of source ‘fs’ can be anywhere in the 4096-byte data space (000h to FFFh) and location of destination ‘fd’ can also be anywhere from 000h to FFFh. Either source or destination can be W (a useful special situation). MOVFF is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). The MOVFF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. The MOVFF instruction should not be used to modify interrupt settings while any interrupt is enabled (see page 73). Words: 2 Cycles: 2 (3) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ (src) Process Data No operation Decode No operation No dummy read No operation Write register ‘f’ (dest) Example: MOVFF REG1, REG2 Before Instruction REG1 = 0x33 REG2 = 0x11 After Instruction REG1 = 0x33, REG2 = 0x33 MOVLB Move literal to low nibble in BSR Syntax: [ label ] MOVLB k Operands: 0 ≤ k ≤ 255 Operation: k → BSR Status Affected: None Encoding: 0000 0001 kkkk kkkk Description: The 8-bit literal ‘k’ is loaded into the Bank Select Register (BSR). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write literal ‘k’ to BSR Example: MOVLB 5 Before Instruction BSR register = 0x02 After Instruction BSR register = 0x05© 2007 Microchip Technology Inc. DS39605F-page 217 PIC18F1220/1320 MOVLW Move literal to W Syntax: [ label ] MOVLW k Operands: 0 ≤ k ≤ 255 Operation: k → W Status Affected: None Encoding: 0000 1110 kkkk kkkk Description: The eight-bit literal ‘k’ is loaded into W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: MOVLW 0x5A After Instruction W = 0x5A MOVWF Move W to f Syntax: [ label ] MOVWF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (W) → f Status Affected: None Encoding: 0110 111a ffff ffff Description: Move data from W to register ‘f’. Location ‘f’ can be anywhere in the 256-byte bank. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: MOVWF REG Before Instruction W = 0x4F REG = 0xFF After Instruction W = 0x4F REG = 0x4FPIC18F1220/1320 DS39605F-page 218 © 2007 Microchip Technology Inc. MULLW Multiply Literal with W Syntax: [ label ] MULLW k Operands: 0 ≤ k ≤ 255 Operation: (W) x k → PRODH:PRODL Status Affected: None Encoding: 0000 1101 kkkk kkkk Description: An unsigned multiplication is carried out between the contents of W and the 8-bit literal ‘k’. The 16-bit result is placed in the PRODH:PRODL register pair. PRODH contains the high byte. W is unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A Zero result is possible but not detected. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write registers PRODH: PRODL Example: MULLW 0xC4 Before Instruction W = 0xE2 PRODH = ? PRODL = ? After Instruction W = 0xE2 PRODH = 0xAD PRODL = 0x08 MULWF Multiply W with f Syntax: [ label ] MULWF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (W) x (f) → PRODH:PRODL Status Affected: None Encoding: 0000 001a ffff ffff Description: An unsigned multiplication is carried out between the contents of W and the register file location ‘f’. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both W and ‘f’ are unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A Zero result is possible, but not detected. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write registers PRODH: PRODL Example: MULWF REG Before Instruction W = 0xC4 REG = 0xB5 PRODH = ? PRODL = ? After Instruction W = 0xC4 REG = 0xB5 PRODH = 0x8A PRODL = 0x94© 2007 Microchip Technology Inc. DS39605F-page 219 PIC18F1220/1320 NEGF Negate f Syntax: [ label ] NEGF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) + 1 → f Status Affected: N, OV, C, DC, Z Encoding: 0110 110a ffff ffff Description: Location ‘f’ is negated using two’s complement. The result is placed in the data memory location ‘f’. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: NEGF REG, 1 Before Instruction REG = 0011 1010 [0x3A] After Instruction REG = 1100 0110 [0xC6] NOP No Operation Syntax: [ label ] NOP Operands: None Operation: No operation Status Affected: None Encoding: 0000 1111 0000 xxxx 0000 xxxx 0000 xxxx Description: No operation. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation Example: None.PIC18F1220/1320 DS39605F-page 220 © 2007 Microchip Technology Inc. POP Pop Top of Return Stack Syntax: [ label ] POP Operands: None Operation: (TOS) → bit bucket Status Affected: None Encoding: 0000 0000 0000 0110 Description: The TOS value is pulled off the return stack and is discarded. The TOS value then becomes the previous value that was pushed onto the return stack. This instruction is provided to enable the user to properly manage the return stack to incorporate a software stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Pop TOS value No operation Example: POP GOTO NEW Before Instruction TOS = 0x0031A2 Stack (1 level down) = 0x014332 After Instruction TOS = 0x014332 PC = NEW PUSH Push Top of Return Stack Syntax: [ label ] PUSH Operands: None Operation: (PC + 2) → TOS Status Affected: None Encoding: 0000 0000 0000 0101 Description: The PC + 2 is pushed onto the top of the return stack. The previous TOS value is pushed down on the stack. This instruction allows implementing a software stack by modifying TOS and then pushing it onto the return stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Push PC + 2 onto return stack No operation No operation Example: PUSH Before Instruction TOS = 0x00345A PC = 0x000124 After Instruction PC = 0x000126 TOS = 0x000126 Stack (1 level down) = 0x00345A© 2007 Microchip Technology Inc. DS39605F-page 221 PIC18F1220/1320 RCALL Relative Call Syntax: [ label ] RCALL n Operands: -1024 ≤ n ≤ 1023 Operation: (PC) + 2 → TOS, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1101 1nnn nnnn nnnn Description: Subroutine call with a jump up to 1K from the current location. First, return address (PC + 2) is pushed onto the stack. Then, add the 2’s complement number ‘2n’ to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Push PC to stack Process Data Write to PC No operation No operation No operation No operation Example: HERE RCALL Jump Before Instruction PC = Address (HERE) After Instruction PC = Address (Jump) TOS = Address (HERE + 2) RESET Reset Syntax: [ label ] RESET Operands: None Operation: Reset all registers and flags that are affected by a MCLR Reset. Status Affected: All Encoding: 0000 0000 1111 1111 Description: This instruction provides a way to execute a MCLR Reset in software. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Start Reset No operation No operation Example: RESET After Instruction Registers = Reset Value Flags* = Reset ValuePIC18F1220/1320 DS39605F-page 222 © 2007 Microchip Technology Inc. RETFIE Return from Interrupt Syntax: [ label ] RETFIE [s] Operands: s ∈ [0,1] Operation: (TOS) → PC, 1 → GIE/GIEH or PEIE/GIEL, if s = 1 (WS) → W, (STATUSS) → Status, (BSRS) → BSR, PCLATU, PCLATH are unchanged. Status Affected: GIE/GIEH, PEIE/GIEL. Encoding: 0000 0000 0001 000s Description: Return from interrupt. Stack is popped and Top-of-Stack (TOS) is loaded into the PC. Interrupts are enabled by setting either the high or low priority global interrupt enable bit. If ‘s’ = 1, the contents of the shadow registers, WS, STATUSS and BSRS, are loaded into their corresponding registers, W, Status and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation Pop PC from stack Set GIEH or GIEL No operation No operation No operation No operation Example: RETFIE 1 After Interrupt PC = TOS W = WS BSR = BSRS Status = STATUSS GIE/GIEH, PEIE/GIEL = 1 RETLW Return Literal to W Syntax: [ label ] RETLW k Operands: 0 ≤ k ≤ 255 Operation: k → W, (TOS) → PC, PCLATU, PCLATH are unchanged Status Affected: None Encoding: 0000 1100 kkkk kkkk Description: W is loaded with the eight-bit literal ‘k’. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Pop PC from stack, Write to W No operation No operation No operation No operation Example: CALL TABLE ; W contains table ; offset value ; W now has ; table value : TABLE ADDWF PCL ; W = offset RETLW k0 ; Begin table RETLW k1 ; : : RETLW kn ; End of table Before Instruction W = 0x07 After Instruction W = value of kn© 2007 Microchip Technology Inc. DS39605F-page 223 PIC18F1220/1320 RETURN Return from Subroutine Syntax: [ label ] RETURN [s] Operands: s ∈ [0,1] Operation: (TOS) → PC, if s = 1 (WS) → W, (STATUSS) → Status, (BSRS) → BSR, PCLATU, PCLATH are unchanged Status Affected: None Encoding: 0000 0000 0001 001s Description: Return from subroutine. The stack is popped and the top of the stack is loaded into the program counter. If ‘s’= 1, the contents of the shadow registers, WS, STATUSS and BSRS, are loaded into their corresponding registers, W, Status and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data Pop PC from stack No operation No operation No operation No operation Example: RETURN After Interrupt PC = TOS RLCF Rotate Left f through Carry Syntax: [ label ] RLCF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<7>) → C, (C) → dest<0> Status Affected: C, N, Z Encoding: 0011 01da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the left through the Carry flag. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: RLCF REG, W Before Instruction REG = 1110 0110 C =0 After Instruction REG = 1110 0110 W = 1100 1100 C =1 C register fPIC18F1220/1320 DS39605F-page 224 © 2007 Microchip Technology Inc. RLNCF Rotate Left f (no carry) Syntax: [ label ] RLNCF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<7>) → dest<0> Status Affected: N, Z Encoding: 0100 01da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the left. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: RLNCF REG Before Instruction REG = 1010 1011 After Instruction REG = 0101 0111 register f RRCF Rotate Right f through Carry Syntax: [ label ] RRCF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<0>) → C, (C) → dest<7> Status Affected: C, N, Z Encoding: 0011 00da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the right through the Carry flag. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: RRCF REG, W Before Instruction REG = 1110 0110 C =0 After Instruction REG = 1110 0110 W = 0111 0011 C =0 C register f© 2007 Microchip Technology Inc. DS39605F-page 225 PIC18F1220/1320 RRNCF Rotate Right f (no carry) Syntax: [ label ] RRNCF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<0>) → dest<7> Status Affected: N, Z Encoding: 0100 00da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the right. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: RRNCF REG, 1, 0 Before Instruction REG = 1101 0111 After Instruction REG = 1110 1011 Example 2: RRNCF REG, W Before Instruction W =? REG = 1101 0111 After Instruction W = 1110 1011 REG = 1101 0111 register f SETF Set f Syntax: [ label ] SETF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: FFh → f Status Affected: None Encoding: 0110 100a ffff ffff Description: The contents of the specified register are set to FFh. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: SETF REG Before Instruction REG = 0x5A After Instruction REG = 0xFFPIC18F1220/1320 DS39605F-page 226 © 2007 Microchip Technology Inc. SLEEP Enter Sleep mode Syntax: [ label ] SLEEP Operands: None Operation: 00h → WDT, 0 → WDT postscaler, 1 → TO, 0 → PD Status Affected: TO, PD Encoding: 0000 0000 0000 0011 Description: The Power-down status bit (PD) is cleared. The Time-out status bit (TO) is set. The Watchdog Timer and its postscaler are cleared. The processor is put into Sleep mode with the oscillator stopped. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data Go to Sleep Example: SLEEP Before Instruction TO = ? PD = ? After Instruction TO = 1 † PD = 0 † If WDT causes wake-up, this bit is cleared. SUBFWB Subtract f from W with borrow Syntax: [ label ] SUBFWB f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) – (f) – (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 01da ffff ffff Description: Subtract register ‘f’ and Carry flag (borrow) from W (2’s complement method). If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: SUBFWB REG Before Instruction REG = 0x03 W = 0x02 C = 0x01 After Instruction REG = 0xFF W = 0x02 C = 0x00 Z = 0x00 N = 0x01 ; result is negative Example 2: SUBFWB REG, 0, 0 Before Instruction REG = 2 W =5 C =1 After Instruction REG = 2 W =3 C =1 Z =0 N = 0 ; result is positive Example 3: SUBFWB REG, 1, 0 Before Instruction REG = 1 W =2 C =0 After Instruction REG = 0 W =2 C =1 Z = 1 ; result is zero N =0© 2007 Microchip Technology Inc. DS39605F-page 227 PIC18F1220/1320 SUBLW Subtract W from literal Syntax: [ label ] SUBLW k Operands: 0 ≤ k ≤ 255 Operation: k – (W) → W Status Affected: N, OV, C, DC, Z Encoding: 0000 1000 kkkk kkkk Description: W is subtracted from the eight-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example 1: SUBLW 0x02 Before Instruction W =1 C =? After Instruction W =1 C = 1 ; result is positive Z =0 N =0 Example 2: SUBLW 0x02 Before Instruction W =2 C =? After Instruction W =0 C = 1 ; result is zero Z =1 N =0 Example 3: SUBLW 0x02 Before Instruction W =3 C =? After Instruction W = FF ; (2’s complement) C = 0 ; result is negative Z =0 N =1 SUBWF Subtract W from f Syntax: [ label ] SUBWF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – (W) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 11da ffff ffff Description: Subtract W from register ‘f’ (2’s complement method). If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: SUBWF REG Before Instruction REG = 3 W =2 C =? After Instruction REG = 1 W =2 C = 1 ; result is positive Z =0 N =0 Example 2: SUBWF REG, W Before Instruction REG = 2 W =2 C =? After Instruction REG = 2 W =0 C = 1 ; result is zero Z =1 N =0 Example 3: SUBWF REG Before Instruction REG = 0x01 W = 0x02 C =? After Instruction REG = 0xFFh ;(2’s complement) W = 0x02 C = 0x00 ;result is negative Z = 0x00 N = 0x01PIC18F1220/1320 DS39605F-page 228 © 2007 Microchip Technology Inc. SUBWFB Subtract W from f with Borrow Syntax: [ label ] SUBWFB f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – (W) – (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 10da ffff ffff Description: Subtract W and the Carry flag (borrow) from register ‘f’ (2’s complement method). If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: SUBWFB REG, 1, 0 Before Instruction REG = 0x19 (0001 1001) W = 0x0D (0000 1101) C = 0x01 After Instruction REG = 0x0C (0000 1011) W = 0x0D (0000 1101) C = 0x01 Z = 0x00 N = 0x00 ; result is positive Example 2: SUBWFB REG, 0, 0 Before Instruction REG = 0x1B (0001 1011) W = 0x1A (0001 1010) C = 0x00 After Instruction REG = 0x1B (0001 1011) W = 0x00 C = 0x01 Z = 0x01 ; result is zero N = 0x00 Example 3: SUBWFB REG, 1, 0 Before Instruction REG = 0x03 (0000 0011) W = 0x0E (0000 1101) C = 0x01 After Instruction REG = 0xF5 (1111 0100) ; [2’s comp] W = 0x0E (0000 1101) C = 0x00 Z = 0x00 N = 0x01 ; result is negative SWAPF Swap f Syntax: [ label ] SWAPF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f<3:0>) → dest<7:4>, (f<7:4>) → dest<3:0> Status Affected: None Encoding: 0011 10da ffff ffff Description: The upper and lower nibbles of register ‘f’ are exchanged. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: SWAPF REG Before Instruction REG = 0x53 After Instruction REG = 0x35© 2007 Microchip Technology Inc. DS39605F-page 229 PIC18F1220/1320 TBLRD Table Read Syntax: [ label ] TBLRD ( *; *+; *-; +*) Operands: None Operation: if TBLRD *, (Prog Mem (TBLPTR)) → TABLAT; TBLPTR – No Change; if TBLRD *+, (Prog Mem (TBLPTR)) → TABLAT; (TBLPTR) + 1 → TBLPTR; if TBLRD *-, (Prog Mem (TBLPTR)) → TABLAT; (TBLPTR) – 1 → TBLPTR; if TBLRD +*, (TBLPTR) + 1 → TBLPTR; (Prog Mem (TBLPTR)) → TABLAT; Status Affected: None Encoding: 0000 0000 0000 10nn nn = 0* = 1*+ = 2*- = 3+* Description: This instruction is used to read the contents of Program Memory (P.M.). To address the program memory, a pointer called Table Pointer (TBLPTR) is used. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-Mbyte address range. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLRD instruction can modify the value of TBLPTR as follows: • no change • post-increment • post-decrement • pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read Program Memory) No operation No operation (Write TABLAT) TBLRD Table Read (Continued) Example 1: TBLRD *+ ; Before Instruction TABLAT = 0x55 TBLPTR = 0x00A356 MEMORY(0x00A356) = 0x34 After Instruction TABLAT = 0x34 TBLPTR = 0x00A357 Example 2: TBLRD +* ; Before Instruction TABLAT = 0xAA TBLPTR = 0x01A357 MEMORY(0x01A357) = 0x12 MEMORY(0x01A358) = 0x34 After Instruction TABLAT = 0x34 TBLPTR = 0x01A358PIC18F1220/1320 DS39605F-page 230 © 2007 Microchip Technology Inc. TBLWT Table Write Syntax: [ label ] TBLWT ( *; *+; *-; +*) Operands: None Operation: if TBLWT*, (TABLAT) → Holding Register; TBLPTR – No Change; if TBLWT*+, (TABLAT) → Holding Register; (TBLPTR) + 1 → TBLPTR; if TBLWT*-, (TABLAT) → Holding Register; (TBLPTR) – 1 → TBLPTR; if TBLWT+*, (TBLPTR) + 1 → TBLPTR; (TABLAT) → Holding Register; Status Affected: None Encoding: 0000 0000 0000 11nn nn = 0* = 1*+ = 2*- = 3+* Description: This instruction uses the 3 LSBs of TBLPTR to determine which of the 8 holding registers the TABLAT is written to. The holding registers are used to program the contents of Program Memory (P.M.). (Refer to Section 6.0 “Flash Program Memory” for additional details on programming Flash memory.) The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-Mbyte address range. The LSb of the TBLPTR selects which byte of the program memory location to access. TBLPTR[0] = 0:Least Significant Byte of Program Memory Word TBLPTR[0] = 1:Most Significant Byte of Program Memory Word The TBLWT instruction can modify the value of TBLPTR as follows: • no change • post-increment • post-decrement • pre-increment TBLWT Table Write (Continued) Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read TABLAT) No operation No operation (Write to Holding Register) Example 1: TBLWT *+; Before Instruction TABLAT = 0x55 TBLPTR = 0x00A356 HOLDING REGISTER (0x00A356) = 0xFF After Instructions (table write completion) TABLAT = 0x55 TBLPTR = 0x00A357 HOLDING REGISTER (0x00A356) = 0x55 Example 2: TBLWT +*; Before Instruction TABLAT = 0x34 TBLPTR = 0x01389A HOLDING REGISTER (0x01389A) = 0xFF HOLDING REGISTER (0x01389B) = 0xFF After Instruction (table write completion) TABLAT = 0x34 TBLPTR = 0x01389B HOLDING REGISTER (0x01389A) = 0xFF HOLDING REGISTER (0x01389B) = 0x34© 2007 Microchip Technology Inc. DS39605F-page 231 PIC18F1220/1320 TSTFSZ Test f, skip if 0 Syntax: [ label ] TSTFSZ f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: skip if f = 0 Status Affected: None Encoding: 0110 011a ffff ffff Description: If ‘f’ = 0, the next instruction, fetched during the current instruction execution is discarded and a NOP is executed, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE TSTFSZ CNT NZERO : ZERO : Before Instruction PC = Address (HERE) After Instruction If CNT = 0x00, PC = Address (ZERO) If CNT ≠ 0x00, PC = Address (NZERO) XORLW Exclusive OR literal with W Syntax: [ label ] XORLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .XOR. k → W Status Affected: N, Z Encoding: 0000 1010 kkkk kkkk Description: The contents of W are XOR’ed with the 8-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: XORLW 0xAF Before Instruction W = 0xB5 After Instruction W = 0x1APIC18F1220/1320 DS39605F-page 232 © 2007 Microchip Technology Inc. XORWF Exclusive OR W with f Syntax: [ label ] XORWF f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .XOR. (f) → dest Status Affected: N, Z Encoding: 0001 10da ffff ffff Description: Exclusive OR the contents of W with register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in the register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: XORWF REG Before Instruction REG = 0xAF W = 0xB5 After Instruction REG = 0x1A W = 0xB5© 2007 Microchip Technology Inc. DS39605F-page 233 PIC18F1220/1320 21.0 DEVELOPMENT SUPPORT The PIC® microcontrollers are supported with a full range of hardware and software development tools: • Integrated Development Environment - MPLAB® IDE Software • Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C18 and MPLAB C30 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian - MPLAB ASM30 Assembler/Linker/Library • Simulators - MPLAB SIM Software Simulator • Emulators - MPLAB ICE 2000 In-Circuit Emulator - MPLAB REAL ICE™ In-Circuit Emulator • In-Circuit Debugger - MPLAB ICD 2 • Device Programmers - PICSTART® Plus Development Programmer - MPLAB PM3 Device Programmer - PICkit™ 2 Development Programmer • Low-Cost Demonstration and Development Boards and Evaluation Kits 21.1 MPLAB Integrated Development Environment Software The MPLAB IDE software brings an ease of software development previously unseen in the 8/16-bit microcontroller market. The MPLAB IDE is a Windows® operating system-based application that contains: • A single graphical interface to all debugging tools - Simulator - Programmer (sold separately) - Emulator (sold separately) - In-Circuit Debugger (sold separately) • A full-featured editor with color-coded context • A multiple project manager • Customizable data windows with direct edit of contents • High-level source code debugging • Visual device initializer for easy register initialization • Mouse over variable inspection • Drag and drop variables from source to watch windows • Extensive on-line help • Integration of select third party tools, such as HI-TECH Software C Compilers and IAR C Compilers The MPLAB IDE allows you to: • Edit your source files (either assembly or C) • One touch assemble (or compile) and download to PIC MCU emulator and simulator tools (automatically updates all project information) • Debug using: - Source files (assembly or C) - Mixed assembly and C - Machine code MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increased flexibility and power.PIC18F1220/1320 DS39605F-page 234 © 2007 Microchip Technology Inc. 21.2 MPASM Assembler The MPASM Assembler is a full-featured, universal macro assembler for all PIC MCUs. The MPASM Assembler generates relocatable object files for the MPLINK Object Linker, Intel® standard HEX files, MAP files to detail memory usage and symbol reference, absolute LST files that contain source lines and generated machine code and COFF files for debugging. The MPASM Assembler features include: • Integration into MPLAB IDE projects • User-defined macros to streamline assembly code • Conditional assembly for multi-purpose source files • Directives that allow complete control over the assembly process 21.3 MPLAB C18 and MPLAB C30 C Compilers The MPLAB C18 and MPLAB C30 Code Development Systems are complete ANSI C compilers for Microchip’s PIC18 family of microcontrollers and the dsPIC30, dsPIC33 and PIC24 family of digital signal controllers. These compilers provide powerful integration capabilities, superior code optimization and ease of use not found with other compilers. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. 21.4 MPLINK Object Linker/ MPLIB Object Librarian The MPLINK Object Linker combines relocatable objects created by the MPASM Assembler and the MPLAB C18 C Compiler. It can link relocatable objects from precompiled libraries, using directives from a linker script. The MPLIB Object Librarian manages the creation and modification of library files of precompiled code. When a routine from a library is called from a source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The object linker/library features include: • Efficient linking of single libraries instead of many smaller files • Enhanced code maintainability by grouping related modules together • Flexible creation of libraries with easy module listing, replacement, deletion and extraction 21.5 MPLAB ASM30 Assembler, Linker and Librarian MPLAB ASM30 Assembler produces relocatable machine code from symbolic assembly language for dsPIC30F devices. MPLAB C30 C Compiler uses the assembler to produce its object file. The assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. Notable features of the assembler include: • Support for the entire dsPIC30F instruction set • Support for fixed-point and floating-point data • Command line interface • Rich directive set • Flexible macro language • MPLAB IDE compatibility 21.6 MPLAB SIM Software Simulator The MPLAB SIM Software Simulator allows code development in a PC-hosted environment by simulating the PIC MCUs and dsPIC® DSCs on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a comprehensive stimulus controller. Registers can be logged to files for further run-time analysis. The trace buffer and logic analyzer display extend the power of the simulator to record and track program execution, actions on I/O, most peripherals and internal registers. The MPLAB SIM Software Simulator fully supports symbolic debugging using the MPLAB C18 and MPLAB C30 C Compilers, and the MPASM and MPLAB ASM30 Assemblers. The software simulator offers the flexibility to develop and debug code outside of the hardware laboratory environment, making it an excellent, economical software development tool. © 2007 Microchip Technology Inc. DS39605F-page 235 PIC18F1220/1320 21.7 MPLAB ICE 2000 High-Performance In-Circuit Emulator The MPLAB ICE 2000 In-Circuit Emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PIC microcontrollers. Software control of the MPLAB ICE 2000 In-Circuit Emulator is advanced by the MPLAB Integrated Development Environment, which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The architecture of the MPLAB ICE 2000 In-Circuit Emulator allows expansion to support new PIC microcontrollers. The MPLAB ICE 2000 In-Circuit Emulator system has been designed as a real-time emulation system with advanced features that are typically found on more expensive development tools. The PC platform and Microsoft® Windows® 32-bit operating system were chosen to best make these features available in a simple, unified application. 21.8 MPLAB REAL ICE In-Circuit Emulator System MPLAB REAL ICE In-Circuit Emulator System is Microchip’s next generation high-speed emulator for Microchip Flash DSC® and MCU devices. It debugs and programs PIC® and dsPIC® Flash microcontrollers with the easy-to-use, powerful graphical user interface of the MPLAB Integrated Development Environment (IDE), included with each kit. The MPLAB REAL ICE probe is connected to the design engineer’s PC using a high-speed USB 2.0 interface and is connected to the target with either a connector compatible with the popular MPLAB ICD 2 system (RJ11) or with the new high speed, noise tolerant, lowvoltage differential signal (LVDS) interconnection (CAT5). MPLAB REAL ICE is field upgradeable through future firmware downloads in MPLAB IDE. In upcoming releases of MPLAB IDE, new devices will be supported, and new features will be added, such as software breakpoints and assembly code trace. MPLAB REAL ICE offers significant advantages over competitive emulators including low-cost, full-speed emulation, real-time variable watches, trace analysis, complex breakpoints, a ruggedized probe interface and long (up to three meters) interconnection cables. 21.9 MPLAB ICD 2 In-Circuit Debugger Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a powerful, low-cost, run-time development tool, connecting to the host PC via an RS-232 or high-speed USB interface. This tool is based on the Flash PIC MCUs and can be used to develop for these and other PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes the in-circuit debugging capability built into the Flash devices. This feature, along with Microchip’s In-Circuit Serial ProgrammingTM (ICSPTM) protocol, offers costeffective, in-circuit Flash debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by setting breakpoints, single stepping and watching variables, and CPU status and peripheral registers. Running at full speed enables testing hardware and applications in real time. MPLAB ICD 2 also serves as a development programmer for selected PIC devices. 21.10 MPLAB PM3 Device Programmer The MPLAB PM3 Device Programmer is a universal, CE compliant device programmer with programmable voltage verification at VDDMIN and VDDMAX for maximum reliability. It features a large LCD display (128 x 64) for menus and error messages and a modular, detachable socket assembly to support various package types. The ICSP™ cable assembly is included as a standard item. In Stand-Alone mode, the MPLAB PM3 Device Programmer can read, verify and program PIC devices without a PC connection. It can also set code protection in this mode. The MPLAB PM3 connects to the host PC via an RS-232 or USB cable. The MPLAB PM3 has high-speed communications and optimized algorithms for quick programming of large memory devices and incorporates an SD/MMC card for file storage and secure data applications.PIC18F1220/1320 DS39605F-page 236 © 2007 Microchip Technology Inc. 21.11 PICSTART Plus Development Programmer The PICSTART Plus Development Programmer is an easy-to-use, low-cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus Development Programmer supports most PIC devices in DIP packages up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus Development Programmer is CE compliant. 21.12 PICkit 2 Development Programmer The PICkit™ 2 Development Programmer is a low-cost programmer and selected Flash device debugger with an easy-to-use interface for programming many of Microchip’s baseline, mid-range and PIC18F families of Flash memory microcontrollers. The PICkit 2 Starter Kit includes a prototyping development board, twelve sequential lessons, software and HI-TECH’s PICC™ Lite C compiler, and is designed to help get up to speed quickly using PIC® microcontrollers. The kit provides everything needed to program, evaluate and develop applications using Microchip’s powerful, mid-range Flash memory family of microcontrollers. 21.13 Demonstration, Development and Evaluation Boards A wide variety of demonstration, development and evaluation boards for various PIC MCUs and dsPIC DSCs allows quick application development on fully functional systems. Most boards include prototyping areas for adding custom circuitry and provide application firmware and source code for examination and modification. The boards support a variety of features, including LEDs, temperature sensors, switches, speakers, RS-232 interfaces, LCD displays, potentiometers and additional EEPROM memory. The demonstration and development boards can be used in teaching environments, for prototyping custom circuits and for learning about various microcontroller applications. In addition to the PICDEM™ and dsPICDEM™ demonstration/development board series of circuits, Microchip has a line of evaluation kits and demonstration software for analog filter design, KEELOQ® security ICs, CAN, IrDA®, PowerSmart® battery management, SEEVAL® evaluation system, Sigma-Delta ADC, flow rate sensing, plus many more. Check the Microchip web page (www.microchip.com) and the latest “Product Selector Guide” (DS00148) for the complete list of demonstration, development and evaluation kits.© 2007 Microchip Technology Inc. DS39605F-page 237 PIC18F1220/1320 22.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings(†) Ambient temperature under bias.............................................................................................................-40°C to +125°C Storage temperature .............................................................................................................................. -65°C to +150°C Voltage on any pin with respect to VSS (except VDD, MCLR and RA4) .......................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +5.5V Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V Voltage on RA4 with respect to Vss............................................................................................................... 0V to +8.5V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. ±20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk by all ports .......................................................................................................................200 mA Maximum current sourced by all ports ..................................................................................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD – ∑ IOH} + ∑ {(VDD – VOH) x IOH} + ∑(VOL x IOL) 2: Voltage spikes below VSS at the MCLR/VPP pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/VPP pin, rather than pulling this pin directly to VSS. † NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.PIC18F1220/1320 DS39605F-page 238 © 2007 Microchip Technology Inc. FIGURE 22-1: PIC18F1220/1320 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL) FIGURE 22-2: PIC18LF1220/1320 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL) Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 40 MHz 5.0V 3.5V 3.0V 2.5V PIC18F1X20 4.2V Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 40 MHz 5.0V 3.5V 3.0V 2.5V FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz Note: VDDAPPMIN is the minimum voltage of the PIC® device in the application. 4 MHz 4.2V PIC18LF1X20© 2007 Microchip Technology Inc. DS39605F-page 239 PIC18F1220/1320 FIGURE 22-3: PIC18F1220/1320 VOLTAGE-FREQUENCY GRAPH (EXTENDED) Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 25 MHz 5.0V 3.5V 3.0V 2.5V PIC18F1X20-E 4.2VPIC18F1220/1320 DS39605F-page 240 © 2007 Microchip Technology Inc. 22.1 DC Characteristics: Supply Voltage PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions VDD Supply Voltage D001 PIC18LF1220/1320 2.0 — 5.5 V HS, XT, RC and LP Oscillator mode PIC18F1220/1320 4.2 — 5.5 V D002 VDR RAM Data Retention Voltage(1) 1.5 — — V D003 VPOR VDD Start Voltage to ensure internal Power-on Reset signal — — 0.7 V See Section 4.1 “Power-on Reset (POR)” for details. D004 SVDD VDD Rise Rate to ensure internal Power-on Reset signal 0.05 — — V/ms See Section 4.1 “Power-on Reset (POR)” for details. VBOR Brown-out Reset Voltage D005D PIC18LF1220/1320 Industrial Low Voltage (-10°C to +85°C) BORV1:BORV0 = 11 N/A N/A N/A V Reserved BORV1:BORV0 = 10 2.50 2.72 2.94 V BORV1:BORV0 = 01 3.88 4.22 4.56 V (Note 2) BORV1:BORV0 = 00 4.18 4.54 4.90 V (Note 2) D005F PIC18LF1220/1320 Industrial Low Voltage (-40°C to -10°C) BORV1:BORV0 = 11 N/A N/A N/A V Reserved BORV1:BORV0 = 10 2.34 2.72 3.10 V BORV1:BORV0 = 01 3.63 4.22 4.81 V (Note 2) BORV1:BORV0 = 00 3.90 4.54 5.18 V (Note 2) D005G PIC18F1220/1320 Industrial (-10°C to +85°C) BORV1:BORV0 = 1x N/A N/A N/A V Reserved BORV1:BORV0 = 01 3.88 4.22 4.56 V (Note 2) BORV1:BORV0 = 00 4.18 4.54 4.90 V (Note 2) D005H PIC18F1220/1320 Industrial (-40°C to -10°C) BORV1:BORV0 = 1x N/A N/A N/A V Reserved BORV1:BORV0 = 01 N/A N/A N/A V Reserved BORV1:BORV0 = 00 3.90 4.54 5.18 V (Note 2) D005J PIC18F1220/1320 Extended (-10°C to +85°C) BORV1:BORV0 = 1x N/A N/A N/A V Reserved BORV1:BORV0 = 01 3.88 4.22 4.56 V (Note 3) BORV1:BORV0 = 00 4.18 4.54 4.90 V (Note 3) D005K PIC18F1220/1320 Extended (-40°C to -10°C, +85°C to +125°C) BORV1:BORV0 = 1x N/A N/A N/A V Reserved BORV1:BORV0 = 01 N/A N/A N/A V Reserved BORV1:BORV0 = 00 3.90 4.54 5.18 V (Note 3) Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data. 2: When BOR is on and BORV<1:0> = 0x, the device will operate correctly at 40 MHz for any VDD at which the BOR allows execution (low-voltage and industrial devices only). 3: When BOR is on and BORV<1:0> = 0x, the device will operate correctly at 25 MHz for any VDD at which the BOR allows execution (extended devices only).© 2007 Microchip Technology Inc. DS39605F-page 241 PIC18F1220/1320 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Power-Down Current (IPD) (1) PIC18LF1220/1320 0.1 0.5 μA -40°C VDD = 2.0V, (Sleep mode) 0.1 0.5 μA +25°C 0.2 1.9 μA +85°C PIC18LF1220/1320 0.1 0.5 μA -40°C VDD = 3.0V, (Sleep mode) 0.1 0.5 μA + 25°C 0.3 1.9 μA +85°C All devices 0.1 2.0 μA -40°C VDD = 5.0V, (Sleep mode) 0.1 2.0 μA +25°C 0.4 6.5 μA +85°C Extended devices 11.2 50 μA +125°C Supply Current (IDD) (2,3) PIC18LF1220/1320 8 40 μA -40°C FOSC = 31 kHz (RC_RUN mode, Internal oscillator source) 9 40 μA +25°C VDD = 2.0V 11 40 μA +85°C PIC18LF1220/1320 25 68 μA -40°C 25 68 μA +25°C VDD = 3.0V 20 68 μA +85°C All devices 55 80 μA -40°C VDD = 5.0V 55 80 μA +25°C 50 80 μA +85°C Extended devices 50 80 μA +125°C Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.PIC18F1220/1320 DS39605F-page 242 © 2007 Microchip Technology Inc. Supply Current (IDD) (2,3) PIC18LF1220/1320 140 220 μA -40°C FOSC = 1 MHz (RC_RUN mode, Internal oscillator source) 145 220 μA +25°C VDD = 2.0V 155 220 μA +85°C PIC18LF1220/1320 215 330 μA -40°C 225 330 μA +25°C VDD = 3.0V 235 330 μA +85°C All devices 385 550 μA -40°C VDD = 5.0V 390 550 μA +25°C 405 550 μA +85°C Extended devices 410 650 μA +125°C PIC18LF1220/1320 410 600 μA -40°C FOSC = 4 MHz (RC_RUN mode, Internal oscillator source) 425 600 μA +25°C VDD = 2.0V 435 600 μA +85°C PIC18LF1220/1320 650 900 μA -40°C 670 900 μA +25°C VDD = 3.0V 680 900 μA +85°C All devices 1.2 1.8 mA -40°C VDD = 5.0V 1.2 1.8 mA +25°C 1.2 1.8 mA +85°C Extended devices 1.2 1.8 mA +125°C 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.© 2007 Microchip Technology Inc. DS39605F-page 243 PIC18F1220/1320 Supply Current (IDD) (2,3) PIC18LF1220/1320 4.7 8 μA -40°C FOSC = 31 kHz (RC_IDLE mode, Internal oscillator source) 5.0 8 μA +25°C VDD = 2.0V 5.8 11 μA +85°C PIC18LF1220/1320 7.0 11 μA -40°C 7.8 11 μA +25°C VDD = 3.0V 8.7 15 μA +85°C All devices 12 16 μA -40°C VDD = 5.0V 14 16 μA +25°C 14 22 μA +85°C Extended devices 25 75 μA +125°C PIC18LF1220/1320 75 150 μA -40°C FOSC = 1 MHz (RC_IDLE mode, Internal oscillator source) 85 150 μA +25°C VDD = 2.0V 95 150 μA +85°C PIC18LF1220/1320 110 180 μA -40°C 125 180 μA +25°C VDD = 3.0V 135 180 μA +85°C All devices 180 380 μA -40°C VDD = 5.0V 195 380 μA +25°C 200 380 μA +85°C Extended devices 350 435 μA +125°C 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.PIC18F1220/1320 DS39605F-page 244 © 2007 Microchip Technology Inc. Supply Current (IDD) (2,3) PIC18LF1220/1320 140 275 μA -40°C FOSC = 4 MHz (RC_IDLE mode, Internal oscillator source) 140 275 μA +25°C VDD = 2.0V 150 275 μA +85°C PIC18LF1220/1320 220 375 μA -40°C 220 375 μA +25°C VDD = 3.0V 220 375 μA +85°C All devices 390 800 μA -40°C VDD = 5.0V 400 800 μA +25°C 380 800 μA +85°C Extended devices 410 800 μA +125°C PIC18LF1220/1320 150 250 μA -40°C FOSC = 1 MHZ (PRI_RUN mode, EC oscillator) 150 250 μA +25°C VDD = 2.0V 160 250 μA +85°C PIC18LF1220/1320 340 350 μA -40°C 300 350 μA +25°C VDD = 3.0V 280 350 μA +85°C All devices 0.72 1.0 mA -40°C VDD = 5.0V 0.63 1.0 mA +25°C 0.58 1.0 mA +85°C Extended devices 0.53 1.0 mA +125°C 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.© 2007 Microchip Technology Inc. DS39605F-page 245 PIC18F1220/1320 Supply Current (IDD) (2,3) PIC18LF1220/1320 415 600 μA -40°C FOSC = 4 MHz (PRI_RUN mode, EC oscillator) 425 600 μA +25°C VDD = 2.0V 435 600 μA +85°C PIC18LF1220/1320 0.87 1.0 mA -40°C 0.75 1.0 mA +25°C VDD = 3.0V 0.75 1.0 mA +85°C All devices 1.6 2.0 mA -40°C VDD = 5.0V 1.6 2.0 mA +25°C 1.5 2.0 mA +85°C Extended devices 1.5 2.0 mA +125°C Extended devices 6.3 9.0 mA +125°C VDD = 4.2V FOSC = 25 MHz (PRI_RUN mode, EC oscillator) 9.7 10.0 mA +125°C VDD = 5.0V All devices 9.4 12 mA -40°C FOSC = 40 MHZ (PRI_RUN mode, EC oscillator) 9.5 12 mA +25°C VDD = 4.2V 9.6 12 mA +85°C All devices 11.9 15 mA -40°C 12.1 15 mA +25°C VDD = 5.0V 12.2 15 mA +85°C 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.PIC18F1220/1320 DS39605F-page 246 © 2007 Microchip Technology Inc. Supply Current (IDD) (2,3) PIC18LF1220/1320 35 50 μA -40°C FOSC = 1 MHz (PRI_IDLE mode, EC oscillator) 35 50 μA +25°C VDD = 2.0V 35 60 μA +85°C PIC18LF1220/1320 55 80 μA -40°C 50 80 μA +25°C VDD = 3.0V 60 100 μA +85°C All devices 105 150 μA -40°C VDD = 5.0V 110 150 μA +25°C 115 150 μA +85°C Extended devices 125 300 μA +125°C PIC18LF1220/1320 135 180 μA -40°C FOSC = 4 MHz (PRI_IDLE mode, EC oscillator) 140 180 μA +25°C VDD = 2.0V 140 180 μA +85°C PIC18LF1220/1320 215 280 μA -40°C 225 280 μA +25°C VDD = 3.0V 230 280 μA +85°C All devices 410 525 μA -40°C VDD = 5.0V 420 525 μA +25°C 430 525 μA +85°C Extended devices 450 800 μA +125°C Extended devices 2.2 3.0 mA +125°C VDD = 4.2V FOSC = 25 MHz (PRI_IDLE mode, EC oscillator) 2.7 3.5 mA +125°C VDD = 5.0V 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.© 2007 Microchip Technology Inc. DS39605F-page 247 PIC18F1220/1320 Supply Current (IDD) (2,3) All devices 3.2 4.1 mA -40°C FOSC = 40 MHz (PRI_IDLE mode, EC oscillator) 3.2 4.1 mA +25°C VDD = 4.2 V 3.3 4.1 mA +85°C All devices 4.0 5.1 mA -40°C 4.1 5.1 mA +25°C VDD = 5.0V 4.1 5.1 mA +85°C PIC18LF1220/1320 5.1 9 μA -10°C FOSC = 32 kHz(4) (SEC_RUN mode, Timer1 as clock) 5.8 9 μA +25°C VDD = 2.0V 7.9 11 μA +70°C PIC18LF1220/1320 7.9 12 μA -10°C 8.9 12 μA +25°C VDD = 3.0V 10.5 14 μA +70°C All devices 12.5 20 μA -10°C 16.3 20 μA +25°C VDD = 5.0V 18.4 25 μA +70°C 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.PIC18F1220/1320 DS39605F-page 248 © 2007 Microchip Technology Inc. Supply Current (IDD) (2,3) PIC18LF1220/1320 9.2 15 μA -10°C FOSC = 32 kHz(4) (SEC_IDLE mode, Timer1 as clock) 9.6 15 μA +25°C VDD = 2.0V 12.7 18 μA +70°C PIC18LF1220/1320 22 30 μA -10°C 21 30 μA +25°C VDD = 3.0V 20 35 μA +70°C All devices 50 80 μA -10°C 45 80 μA +25°C VDD = 5.0V 45 80 μA +70°C 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.© 2007 Microchip Technology Inc. DS39605F-page 249 PIC18F1220/1320 Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔIOSCB, ΔIAD) D022 (ΔIWDT) Watchdog Timer 1.5 4.0 μA -40°C 2.2 4.0 μA +25°C VDD = 2.0V 3.1 5.0 μA +85°C 2.5 6.0 μA -40°C 3.3 6.0 μA +25°C VDD = 3.0V 4.7 7.0 μA +85°C 3.7 10.0 μA -40°C 4.5 10.0 μA +25°C VDD = 5.0V 6.1 13.0 μA +85°C D022A (ΔIBOR) Brown-out Reset 19 35.0 μA -40°C to +85°C VDD = 3.0V 24 45.0 μA -40°C to +85°C VDD = 5.0V D022B (ΔILVD) Low-Voltage Detect 8.5 25.0 μA -40°C to +85°C VDD = 2.0V 16 35.0 μA -40°C to +85°C VDD = 3.0V 20 45.0 μA -40°C to +85°C VDD = 5.0V D025 (ΔIOSCB) Timer1 Oscillator 1.7 3.5 μA -40°C 1.8 3.5 μA +25°C VDD = 2.0V 32 kHz on Timer1(4) 2.1 4.5 μA +85°C 2.2 4.5 μA -40°C 2.6 4.5 μA +25°C VDD = 3.0V 32 kHz on Timer1(4) 2.8 5.5 μA +85°C 3.0 6.0 μA -40°C 3.3 6.0 μA +25°C VDD = 5.0V 32 kHz on Timer1(4) 3.6 7.0 μA +85°C D026 (ΔIAD) A/D Converter 1.0 3.0 μA -40°C to +85°C VDD = 2.0V A/D on, not converting 1.0 4.0 μA -40°C to +85°C VDD = 3.0V 2.0 10.0 μA -40°C to +85°C VDD = 5.0V 1.0 8.0 μA -40°C to +125°C VDD = 5.0V 22.2 DC Characteristics: Power-Down and Supply Current PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ. 4: Standard low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature crystals are available at a much higher cost.PIC18F1220/1320 DS39605F-page 250 © 2007 Microchip Technology Inc. 22.3 DC Characteristics: PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Max Units Conditions VIL Input Low Voltage I/O ports: D030 with TTL buffer VSS 0.15 VDD V VDD < 4.5V D030A — 0.8 V 4.5V ≤ VDD ≤ 5.5V D031 with Schmitt Trigger buffer VSS 0.2 VDD V D032 MCLR VSS 0.2 VDD V D032A OSC1 (in XT, HS and LP modes) and T1OSI VSS 0.3 VDD V D033 OSC1 (in RC and EC mode)(1) VSS 0.2 VDD V VIH Input High Voltage I/O ports: D040 with TTL buffer 0.25 VDD + 0.8V VDD V VDD < 4.5V D040A 2.0 VDD V 4.5V ≤ VDD ≤ 5.5V D041 with Schmitt Trigger buffer 0.8 VDD VDD V D042 MCLR, OSC1 (EC mode) 0.8 VDD VDD V D042A OSC1 (in XT, HS and LP modes) and T1OSI 1.6 VDD VDD V D043 OSC1 (RC mode)(1) 0.9 VDD VDD V IIL Input Leakage Current(2,3) D060 I/O ports — ±1 μA VSS ≤ VPIN ≤ VDD, Pin at high-impedance D061 MCLR — ±5 μA VSS ≤ VPIN ≤ VDD D063 OSC1 — ±5 μA VSS ≤ VPIN ≤ VDD IPU Weak Pull-up Current D070 IPURB PORTB weak pull-up current 50 400 μA VDD = 5V, VPIN = VSS Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC® device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: Parameter is characterized but not tested.© 2007 Microchip Technology Inc. DS39605F-page 251 PIC18F1220/1320 VOL Output Low Voltage D080 I/O ports — 0.6 V IOL = 8.5 mA, VDD = 4.5V, -40°C to +85°C D083 OSC2/CLKO (RC mode) — 0.6 V IOL = 1.6 mA, VDD = 4.5V, -40°C to +85°C VOH Output High Voltage(3) D090 I/O ports VDD – 0.7 — V IOH = -3.0 mA, VDD = 4.5V, -40°C to +85°C D092 OSC2/CLKO (RC mode) VDD – 0.7 — V IOH = -1.3 mA, VDD = 4.5V, -40°C to +85°C D150 VOD Open-Drain High Voltage — 8.5 V RA4 pin Capacitive Loading Specs on Output Pins D100(4) COSC2 OSC2 pin — 15 pF In XT, HS and LP modes when external clock is used to drive OSC1 D101 CIO All I/O pins and OSC2 (in RC mode) — 50 pF To meet the AC timing specifications D102 CB SCL, SDA — 400 pF In I2C mode 22.3 DC Characteristics: PIC18F1220/1320 (Industrial) PIC18LF1220/1320 (Industrial) (Continued) DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Max Units Conditions Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC® device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: Parameter is characterized but not tested.PIC18F1220/1320 DS39605F-page 252 © 2007 Microchip Technology Inc. TABLE 22-1: MEMORY PROGRAMMING REQUIREMENTS DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Param No. Sym Characteristic Min Typ† Max Units Conditions Internal Program Memory Programming Specifications(1) D110 VPP Voltage on MCLR/VPP pin 9.00 — 13.25 V (Note 2) D112 IPP Current into MCLR/VPP pin — — 5 μA D113 IDDP Supply Current during Programming — — 10 mA Data EEPROM Memory D120 ED Byte Endurance 100K 1M — E/W -40°C to +85°C D121 VDRW VDD for Read/Write VMIN — 5.5 V Using EECON to read/write VMIN = Minimum operating voltage D122 TDEW Erase/Write Cycle Time — 4 — ms D123 TRETD Characteristic Retention 40 — — Year Provided no other specifications are violated D124 TREF Number of Total Erase/Write Cycles before Refresh(3) 1M 10M — E/W -40°C to +85°C Program Flash Memory D130 EP Cell Endurance 10K 100K — E/W -40°C to +85°C D131 VPR VDD for Read VMIN — 5.5 V VMIN = Minimum operating voltage D132 VIE VDD for Block Erase 4.5 — 5.5 V Using ICSP port D132A VIW VDD for Externally Timed Erase or Write 4.5 — 5.5 V Using ICSP port D132B VPEW VDD for Self-Timed Write VMIN — 5.5 V VMIN = Minimum operating voltage D133 TIE ICSP™ Block Erase Cycle Time — 4 — ms VDD > 4.5V D133A TIW ICSP Erase or Write Cycle Time (externally timed) 1 — — ms VDD > 4.5V D133A TIW Self-Timed Write Cycle Time — 2 — ms D134 TRETD Characteristic Retention 40 — — Year Provided no other specifications are violated † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: These specifications are for programming the on-chip program memory through the use of table write instructions. 2: The pin may be kept in this range at times other than programming, but it is not recommended. 3: Refer to Section 7.8 “Using the Data EEPROM” for a more detailed discussion on data EEPROM endurance.© 2007 Microchip Technology Inc. DS39605F-page 253 PIC18F1220/1320 FIGURE 22-4: LOW-VOLTAGE DETECT CHARACTERISTICS VLVD LVDIF VDD (LVDIF set by hardware) (LVDIF can be cleared in software) TABLE 22-2: LOW-VOLTAGE DETECT CHARACTERISTICS PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ† Max Units Conditions D420D LVD Voltage on VDD Transition High-to-Low Industrial Low Voltage (-10°C to +85°C) PIC18LF1220/1320 LVDL<3:0> = 0000 N/A N/A N/A V Reserved LVDL<3:0> = 0001 N/A N/A N/A V Reserved LVDL<3:0> = 0010 2.08 2.26 2.44 V LVDL<3:0> = 0011 2.26 2.45 2.65 V LVDL<3:0> = 0100 2.35 2.55 2.76 V LVDL<3:0> = 0101 2.55 2.77 2.99 V LVDL<3:0> = 0110 2.64 2.87 3.10 V LVDL<3:0> = 0111 2.82 3.07 3.31 V LVDL<3:0> = 1000 3.09 3.36 3.63 V LVDL<3:0> = 1001 3.29 3.57 3.86 V LVDL<3:0> = 1010 3.38 3.67 3.96 V LVDL<3:0> = 1011 3.56 3.87 4.18 V LVDL<3:0> = 1100 3.75 4.07 4.40 V LVDL<3:0> = 1101 3.93 4.28 4.62 V LVDL<3:0> = 1110 4.23 4.60 4.96 V Legend: Shading of rows is to assist in readability of the table. † Production tested at TAMB = 25°C. Specifications over temperature limits ensured by characterization.PIC18F1220/1320 DS39605F-page 254 © 2007 Microchip Technology Inc. D420F LVD Voltage on VDD Transition High-to-Low Industrial Low Voltage (-40°C to -10°C) PIC18LF1220/1320 LVDL<3:0> = 0000 N/A N/A N/A V Reserved LVDL<3:0> = 0001 N/A N/A N/A V Reserved LVDL<3:0> = 0010 1.99 2.26 2.53 V LVDL<3:0> = 0011 2.16 2.45 2.75 V LVDL<3:0> = 0100 2.25 2.55 2.86 V LVDL<3:0> = 0101 2.43 2.77 3.10 V LVDL<3:0> = 0110 2.53 2.87 3.21 V LVDL<3:0> = 0111 2.70 3.07 3.43 V LVDL<3:0> = 1000 2.96 3.36 3.77 V LVDL<3:0> = 1001 3.14 3.57 4.00 V LVDL<3:0> = 1010 3.23 3.67 4.11 V LVDL<3:0> = 1011 3.41 3.87 4.34 V LVDL<3:0> = 1100 3.58 4.07 4.56 V LVDL<3:0> = 1101 3.76 4.28 4.79 V LVDL<3:0> = 1110 4.04 4.60 5.15 V LVD Voltage on VDD Transition High-to-Low Industrial (-10°C to +85°C) D420G PIC18F1220/1320 LVDL<3:0> = 1101 3.93 4.28 4.62 V LVDL<3:0> = 1110 4.23 4.60 4.96 V LVD Voltage on VDD Transition High-to-Low Industrial (-40°C to -10°C) D420H PIC18F1220/1320 LVDL<3:0> = 1101 3.76 4.28 4.79 V LVDL<3:0> = 1110 4.04 4.60 5.15 V LVD Voltage on VDD Transition High-to-Low Extended (-10°C to +85°C) D420J PIC18F1220/1320 LVDL<3:0> = 1101 3.94 4.28 4.62 V LVDL<3:0> = 1110 4.23 4.60 4.96 V LVD Voltage on VDD Transition High-to-Low Extended (-40°C to -10°C, +85°C to +125°C) D420K PIC18F1220/1320 LVDL<3:0> = 1101 3.77 4.28 4.79 V LVDL<3:0> = 1110 4.05 4.60 5.15 V TABLE 22-2: LOW-VOLTAGE DETECT CHARACTERISTICS (CONTINUED) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ† Max Units Conditions Legend: Shading of rows is to assist in readability of the table. † Production tested at TAMB = 25°C. Specifications over temperature limits ensured by characterization.© 2007 Microchip Technology Inc. DS39605F-page 255 PIC18F1220/1320 22.4 AC (Timing) Characteristics 22.4.1 TIMING PARAMETER SYMBOLOGY The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 3. TCC:ST (I2C specifications only) 2. TppS 4. Ts (I2C specifications only) T F Frequency T Time Lowercase letters (pp) and their meanings: pp cc CCP1 osc OSC1 ck CLKO rd RD cs CS rw RD or WR di SDI sc SCK do SDO ss SS dt Data in t0 T0CKI io I/O port t1 T13CKI mc MCLR wr WR Uppercase letters and their meanings: S F Fall P Period H High R Rise I Invalid (High-Impedance) V Valid L Low Z High-Impedance I 2C only AA output access High High BUF Bus free Low Low TCC:ST (I2C specifications only) CC HD Hold SU Setup ST DAT DATA input hold STO Stop condition STA Start conditionPIC18F1220/1320 DS39605F-page 256 © 2007 Microchip Technology Inc. 22.4.2 TIMING CONDITIONS The temperature and voltages specified in Table 22-3 apply to all timing specifications unless otherwise noted. Figure 22-5 specifies the load conditions for the timing specifications. TABLE 22-3: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC FIGURE 22-5: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS AC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Operating voltage VDD range as described in DC spec Section 22.1 and Section 22.3. LF parts operate for industrial temperatures only. VDD/2 CL RL pin Pin VSS VSS CL RL = 464Ω CL = 50 pF for all pins except OSC2/CLKO Load Condition 1 Load Condition 2© 2007 Microchip Technology Inc. DS39605F-page 257 PIC18F1220/1320 22.4.3 TIMING DIAGRAMS AND SPECIFICATIONS FIGURE 22-6: EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL) TABLE 22-4: EXTERNAL CLOCK TIMING REQUIREMENTS OSC1 CLKO Q4 Q1 Q2 Q3 Q4 Q1 1 2 3 3 4 4 Param. No. Symbol Characteristic Min Max Units Conditions 1A FOSC External CLKI Frequency(1) DC 40 MHz EC, ECIO (LF and Industrial) DC 25 MHz EC, ECIO (Extended) Oscillator Frequency(1) DC 4 MHz RC oscillator DC 1 MHz XT oscillator DC 25 MHz HS oscillator 1 10 MHz HS + PLL oscillator DC 33 kHz LP Oscillator mode 1 TOSC External CLKI Period(1) 25 — ns EC, ECIO (LF and Industrial) 40 — ns EC, ECIO (Extended) Oscillator Period(1) 250 — ns RC oscillator 1000 — ns XT oscillator 25 100 — 1000 ns ns HS oscillator HS + PLL oscillator 30 — μs LP oscillator 2 TCY Instruction Cycle Time(1) 100 — ns TCY = 4/FOSC 3 TosL, TosH External Clock in (OSC1) High or Low Time 30 — ns XT oscillator 2.5 — μs LP oscillator 10 — ns HS oscillator 4 TosR, TosF External Clock in (OSC1) Rise or Fall Time — 20 ns XT oscillator — 50 ns LP oscillator — 7.5 ns HS oscillator Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations except PLL. All specified values are based on characterization data for that particular oscillator type under standard operating conditions, with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.PIC18F1220/1320 DS39605F-page 258 © 2007 Microchip Technology Inc. TABLE 22-5: PLL CLOCK TIMING SPECIFICATIONS, HS/HSPLL MODE (VDD = 4.2V TO 5.5V) Param No. Sym Characteristic Min Typ† Max Units Conditions F10 FOSC Oscillator Frequency Range 4 — 10 MHz HS and HSPLL mode only F11 FSYS On-Chip VCO System Frequency 16 — 40 MHz HSPLL mode only F12 TPLL PLL Start-up Time (Lock Time) — — 2 ms HSPLL mode only F13 ΔCLK CLKO Stability (Jitter) -2 — +2 % HSPLL mode only † Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. TABLE 22-6: INTERNAL RC ACCURACY: PIC18F1220/1320 (INDUSTRIAL) PIC18LF1220/1320 (INDUSTRIAL) PIC18LF1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F1220/1320 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Min Typ Max Units Conditions INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz(1) PIC18LF1220/1320 -2 +/-1 2 % +25°C VDD = 2.7-3.3V -5 — 5 % -10°C to +85°C VDD = 2.7-3.3V -10 — 10 % -40°C to +85°C VDD = 2.7-3.3V PIC18F1220/1320PIC18F 1220/1320 -2 +/-1 2 % +25°C VDD = 4.5-5.5V -5 — 5 % -10°C to +85°C VDD = 4.5-5.5V -10 — 10 % -40°C to +85°C VDD = 4.5-5.5V INTRC Accuracy @ Freq = 31 kHz(2) PIC18LF1220/1320 26.562 — 35.938 kHz -40°C to +85°C VDD = 2.7-3.3V PIC18F1220/1320PIC18F 1220/1320 26.562 — 35.938 kHz -40°C to +85°C VDD = 4.5-5.5V Legend: Shading of rows is to assist in readability of the table. Note 1: Frequency calibrated at 25°C. OSCTUNE register can be used to compensate for temperature and VDD drift. 2: INTRC frequency after calibration. 3: Change of INTRC frequency as VDD changes.© 2007 Microchip Technology Inc. DS39605F-page 259 PIC18F1220/1320 FIGURE 22-7: CLKO AND I/O TIMING TABLE 22-7: CLKO AND I/O TIMING REQUIREMENTS Note: Refer to Figure 22-5 for load conditions. OSC1 CLKO I/O pin (Input) I/O pin (Output) Q4 Q1 Q2 Q3 10 13 14 17 20, 21 19 18 15 11 12 16 Old Value New Value Param. No. Symbol Characteristic Min Typ Max Units Conditions 10 TosH2ckL OSC1↑ to CLKO↓ — 75 200 ns (Note 1) 11 TosH2ckH OSC1↑ to CLKO↑ — 75 200 ns (Note 1) 12 TckR CLKO Rise Time — 35 100 ns (Note 1) 13 TckF CLKO Fall Time — 35 100 ns (Note 1) 14 TckL2ioV CLKO↓ to Port Out Valid — — 0.5 TCY + 20 ns (Note 1) 15 TioV2ckH Port In Valid before CLKO↑ 0.25 TCY + 25 — — ns (Note 1) 16 TckH2ioI Port In Hold after CLKO↑ 0 — — ns (Note 1) 17 TosH2ioV OSC1↑ (Q1 cycle) to Port Out Valid — 50 150 ns 18 TosH2ioI OSC1↑ (Q2 cycle) to Port Input Invalid (I/O in hold time) PIC18F1X20 100 — — ns 18A PIC18LF1X20 200 — — ns 19 TioV2osH Port Input Valid to OSC1↑ (I/O in setup time) 0 — — ns 20 TioR Port Output Rise Time PIC18F1X20 — 10 25 ns 20A PIC18LF1X20 — — 60 ns 21 TioF Port Output Fall Time PIC18F1X20 — 10 25 ns 21A PIC18LF1X20 — — 60 ns Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.PIC18F1220/1320 DS39605F-page 260 © 2007 Microchip Technology Inc. FIGURE 22-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING FIGURE 22-9: BROWN-OUT RESET TIMING VDD MCLR Internal POR PWRT Time-out OSC Time-out Internal Reset Watchdog Timer Reset 33 32 30 31 34 I/O pins 34 Note: Refer to Figure 22-5 for load conditions. VDD BVDD 35 VBGAP = 1.2V VIRVST Enable Internal Internal Reference 36 Reference Voltage Voltage Stable© 2007 Microchip Technology Inc. DS39605F-page 261 PIC18F1220/1320 TABLE 22-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER AND BROWN-OUT RESET REQUIREMENTS FIGURE 22-10: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS Param. No. Symbol Characteristic Min Typ Max Units Conditions 30 TmcL MCLR Pulse Width (low) 2 — — μs 31 TWDT Watchdog Timer Time-out Period (No postscaler) 3.48 4.00 4.71 ms 32 TOST Oscillation Start-up Timer Period 1024 TOSC — 1024 TOSC — TOSC = OSC1 period 33 TPWRT Power-up Timer Period — 65.5 132 ms 34 TIOZ I/O High-Impedance from MCLR Low or Watchdog Timer Reset —2— μs 35 TBOR Brown-out Reset Pulse Width 200 — — μs VDD ≤ BVDD (see D005) 36 TIVRST Time for Internal Reference Voltage to become stable — 20 50 μs 37 TLVD Low-Voltage Detect Pulse Width 200 — — μs VDD ≤ VLVD Note: Refer to Figure 22-5 for load conditions. 46 47 45 48 41 42 40 T0CKI T1OSO/T13CKI TMR0 or TMR1PIC18F1220/1320 DS39605F-page 262 © 2007 Microchip Technology Inc. TABLE 22-9: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS FIGURE 22-11: CAPTURE/COMPARE/PWM TIMINGS (ALL CCP MODULES) Param No. Symbol Characteristic Min Max Units Conditions 40 Tt0H T0CKI High Pulse Width No prescaler 0.5 TCY + 20 — ns With prescaler 10 — ns 41 Tt0L T0CKI Low Pulse Width No prescaler 0.5 TCY + 20 — ns With prescaler 10 — ns 42 Tt0P T0CKI Period No prescaler TCY + 10 — ns With prescaler Greater of: 20 ns or TCY + 40 N — ns N = prescale value (1, 2, 4,..., 256) 45 Tt1H T13CKI High Time Synchronous, no prescaler 0.5 TCY + 20 — ns Synchronous, with prescaler PIC18F1X20 10 — ns PIC18LF1X20 25 — ns Asynchronous PIC18F1X20 30 — ns PIC18LF1X20 50 — ns 46 Tt1L T13CKI Low Time Synchronous, no prescaler 0.5 TCY + 5 — ns Synchronous, with prescaler PIC18F1X20 10 — ns PIC18LF1X20 25 — ns Asynchronous PIC18F1X20 30 — ns PIC18LF1X20 50 — ns 47 Tt1P T13CKI Input Period Synchronous Greater of: 20 ns or TCY + 40 N — ns N = prescale value (1, 2, 4, 8) Asynchronous 60 — ns Ft1 T13CKI Oscillator Input Frequency Range DC 50 kHz 48 Tcke2tmrI Delay from External T13CKI Clock Edge to Timer Increment 2 TOSC 7 TOSC — Note: Refer to Figure 22-5 for load conditions. CCPx (Capture Mode) 50 51 52 CCPx 53 54 (Compare or PWM Mode)© 2007 Microchip Technology Inc. DS39605F-page 263 PIC18F1220/1320 TABLE 22-10: CAPTURE/COMPARE/PWM REQUIREMENTS (ALL CCP MODULES) FIGURE 22-12: EUSART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING TABLE 22-11: EUSART SYNCHRONOUS TRANSMISSION REQUIREMENTS Param. No. Symbol Characteristic Min Max Units Conditions 50 TccL CCPx Input Low Time No prescaler 0.5 TCY + 20 — ns With prescaler PIC18F1X20 10 — ns PIC18LF1X20 20 — ns 51 TccH CCPx Input High Time No prescaler 0.5 TCY + 20 — ns With prescaler PIC18F1X20 10 — ns PIC18LF1X20 20 — ns 52 TccP CCPx Input Period 3 TCY + 40 N — ns N = prescale value (1, 4 or 16) 53 TccR CCPx Output Fall Time PIC18F1X20 — 25 ns PIC18LF1X20 — 45 ns 54 TccF CCPx Output Fall Time PIC18F1X20 — 25 ns PIC18LF1X20 — 45 ns 121 121 120 122 RB1/AN5/TX/ RB4/AN6/RX/ DT/KBI0 pin CK/INT1 pin Note: Refer to Figure 22-5 for load conditions. Param. No. Symbol Characteristic Min Max Units Conditions 120 TckH2dtV SYNC XMIT (MASTER & SLAVE) Clock High to Data Out Valid PIC18F1X20 — 40 ns PIC18LF1X20 — 100 ns 121 Tckrf Clock Out Rise Time and Fall Time (Master mode) PIC18F1X20 — 20 ns PIC18LF1X20 — 50 ns 122 Tdtrf Data Out Rise Time and Fall Time PIC18F1X20 — 20 ns PIC18LF1X20 — 50 nsPIC18F1220/1320 DS39605F-page 264 © 2007 Microchip Technology Inc. FIGURE 22-13: EUSART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING TABLE 22-12: EUSART SYNCHRONOUS RECEIVE REQUIREMENTS TABLE 22-13: A/D CONVERTER CHARACTERISTICS: PIC18F1220/1320 (INDUSTRIAL) PIC18LF1220/1320 (INDUSTRIAL) Param. No. Symbol Characteristic Min Max Units Conditions 125 TdtV2ckl SYNC RCV (MASTER & SLAVE) Data Hold before CK↓ (DT hold time) 10 — ns 126 TckL2dtl Data Hold after CK↓ (DT hold time) 15 — ns Param No. Symbol Characteristic Min Typ Max Units Conditions A01 NR Resolution — — 10 bit ΔVREF ≥ 3.0V A03 EIL Integral Linearity Error — — <±1 LSb ΔVREF ≥ 3.0V A04 EDL Differential Linearity Error — — <±1 LSb ΔVREF ≥ 3.0V A06 EOFF Offset Error — — <±1 LSb ΔVREF ≥ 3.0V A07 EGN Gain Error — — <±1 LSb ΔVREF ≥ 3.0V A10 — Monotonicity guaranteed(2) — A20 ΔVREF Reference Voltage Range (VREFH – VREFL) 3 — AVDD – AVSS V For 10-bit resolution A21 VREFH Reference Voltage High AVSS + 3.0V — AVDD + 0.3V V For 10-bit resolution A22 VREFL Reference Voltage Low AVSS – 0.3V — AVDD – 3.0V V For 10-bit resolution A25 VAIN Analog Input Voltage VREFL — VREFH V A28 AVDD Analog Supply Voltage VDD – 0.3 — VDD + 0.3 V A29 AVSS Analog Supply Voltage VSS – 0.3 — VSS + 0.3 V A30 ZAIN Recommended Impedance of Analog Voltage Source — — 2.5 kΩ A40 IAD A/D Conversion Current (VDD) PIC18F1X20 — 180 — μA Average current consumption when A/D is on (Note 1) PIC18LF1X20 — 90 — μA A50 IREF VREF Input Current (Note 3) — — — — ±5 ±150 μA μA During VAIN acquisition. During A/D conversion cycle. Note 1: When A/D is off, it will not consume any current other than minor leakage current. The power-down current specification includes any such leakage from the A/D module. 2: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes. 3: VREFH current is from RA3/AN3/VREF+ pin or AVDD, whichever is selected as the VREFH source. VREFL current is from RA2/AN2/VREF- pin or AVSS, whichever is selected as the VREFL source. 125 126 Note: Refer to Figure 22-5 for load conditions. RB1/AN5/TX/ RB4/AN6/RX/ DT/KBI0 pin CK/INT1 pin© 2007 Microchip Technology Inc. DS39605F-page 265 PIC18F1220/1320 FIGURE 22-14: A/D CONVERSION TIMING TABLE 22-14: A/D CONVERSION REQUIREMENTS 131 130 132 BSF ADCON0, GO Q4 A/D CLK(1) A/D DATA ADRES ADIF GO SAMPLE OLD_DATA Sampling Stopped DONE NEW_DATA (Note 2) 9 87 2 1 0 Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. 2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input. . . . . . . TCY Param No. Symbol Characteristic Min Max Units Conditions 130 TAD A/D Clock Period PIC18F1X20 1.6 20(5) μs TOSC based, VREF ≥ 3.0V PIC18LF1X20 3.0 20(5) μs TOSC based, VREF full range PIC18F1X20 2.0 6.0 μs A/D RC mode PIC18LF1X20 3.0 9.0 μs A/D RC mode 131 TCNV Conversion Time (not including acquisition time) (Note 1) 11 12 TAD 132 TACQ Acquisition Time (Note 3) 15 10 — — μs μs -40°C ≤ Temp ≤ +125°C 0°C ≤ Temp ≤ +125°C 135 TSWC Switching Time from Convert → Sample — (Note 4) 136 TAMP Amplifier Settling Time (Note 2) 1 — μs This may be used if the “new” input voltage has not changed by more than 1 LSb (i.e., 5 mV @ 5.12V) from the last sampled voltage (as stated on CHOLD). Note 1: ADRES register may be read on the following TCY cycle. 2: See Section 17.0 “10-Bit Analog-to-Digital Converter (A/D) Module” for minimum conditions when input voltage has changed more than 1 LSb. 3: The time for the holding capacitor to acquire the “New” input voltage, when the voltage changes full scale after the conversion (AVDD to AVSS, or AVSS to AVDD). The source impedance (RS) on the input channels is 50Ω. 4: On the next Q4 cycle of the device clock. 5: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider. PIC18F1220/1320 DS39605F-page 266 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 267 PIC18F1220/1320 23.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES “Typical” represents the mean of the distribution at 25°C. “Maximum” or “minimum” represents (mean + 3σ) or (mean – 3σ) respectively, where σ is a standard deviation, over the whole temperature range. FIGURE 23-1: TYPICAL IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, +25°C FIGURE 23-2: MAXIMUM IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, -40°C TO +85°C Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore, outside the warranted range. 0.0 0.1 0.2 0.3 0.4 0.5 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 268 © 2007 Microchip Technology Inc. FIGURE 23-3: MAXIMUM IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, -40°C TO +125°C FIGURE 23-4: TYPICAL IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, +25°C 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 269 PIC18F1220/1320 FIGURE 23-5: MAXIMUM IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, -40°C TO +125°C FIGURE 23-6: TYPICAL IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, +25°C 0.0 0.5 1.0 1.5 2.0 2.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0 2 4 6 8 10 12 14 16 4 8 12 16 20 24 28 32 36 40 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 270 © 2007 Microchip Technology Inc. FIGURE 23-7: MAXIMUM IDD vs. FOSC OVER VDD PRI_RUN, EC MODE, -40°C TO +125°C FIGURE 23-8: TYPICAL IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, +25°C 0 2 4 6 8 10 12 14 16 4 8 12 16 20 24 28 32 36 40 FOSC (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 FOSC (MHz) IDD (mA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 271 PIC18F1220/1320 FIGURE 23-9: MAXIMUM IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, -40°C TO +85°C FIGURE 23-10: MAXIMUM IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, -40°C TO +125°C 0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 FOSC (MHz) IDD (mA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 FOSC (MHz) IDD (mA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 272 © 2007 Microchip Technology Inc. FIGURE 23-11: TYPICAL IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, +25°C FIGURE 23-12: MAXIMUM IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, -40°C TO +125°C Typical I vs F over V PRI_IDLE, EC mode, +25°C 0 100 200 300 400 500 600 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FOSC (MHz) IDD (μA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0 100 200 300 400 500 600 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FOSC (MHz) IDD (μA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 273 PIC18F1220/1320 FIGURE 23-13: TYPICAL IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, +25°C FIGURE 23-14: MAXIMUM IDD vs. FOSC OVER VDD PRI_IDLE, EC MODE, -40°C TO +125°C 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 4 8 12 16 20 24 28 32 36 40 FOSC (MHz) IDD (mA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 4 8 12 16 20 24 28 32 36 40 FOSC (MHz) IDD (mA) 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 5.0V 5.5V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 274 © 2007 Microchip Technology Inc. FIGURE 23-15: TYPICAL IPD vs. VDD (+25°C), 125 kHz TO 8 MHz RC_RUN MODE, ALL PERIPHERALS DISABLED FIGURE 23-16: MAXIMUM IPD vs. VDD (-40°C TO +125°C), 125 kHz TO 8 MHz RC_RUN MODE, ALL PERIPHERALS DISABLED 0 500 1000 1500 2000 2500 3000 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) 8 MHz 125 kHz 4 MHz 2 MHz 1 MHz 250 kHz and 500 kHz curves are bounded by 125 kHz and 1 MHz curves. Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0 500 1000 1500 2000 2500 3000 3500 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) 8 MHz 125 kHz 4 MHz 2 MHz 1 MHz 250 kHz and 500 kHz curves are bounded by 125 kHz and 1 MHz curves. Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 275 PIC18F1220/1320 FIGURE 23-17: TYPICAL AND MAXIMUM IPD vs. VDD (-40°C TO +125°C), 31.25 kHz RC_RUN MODE, ALL PERIPHERALS DISABLED FIGURE 23-18: TYPICAL IPD vs. VDD (+25°C), 125 kHz TO 8 MHz RC_IDLE MODE, ALL PERIPHERALS DISABLED 1 10 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Typ (+25°C) Max (+85°C) Max (+125°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) 8 MHz 125 kHz 4 MHz 2 MHz 1 MHz 250 kHz and 500 kHz curves are bounded by 125 kHz and 1 MHz curves. Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 276 © 2007 Microchip Technology Inc. FIGURE 23-19: MAXIMUM IPD vs. VDD (-40°C TO +125°C), 125 kHz TO 8 MHz RC_IDLE MODE, ALL PERIPHERALS DISABLED FIGURE 23-20: TYPICAL AND MAXIMUM IPD vs. VDD (-40°C TO +125°C), 31.25 kHz RC_IDLE MODE, ALL PERIPHERALS DISABLED 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) 8 MHz 125 kHz 4 MHz 2 MHz 1 MHz 250 kHz and 500 kHz curves are bounded by 125 kHz and 1 MHz curves. Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 1 10 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Typ (+25°C) Max (+85°C) Max (+125°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 277 PIC18F1220/1320 FIGURE 23-21: IPD SEC_RUN MODE, -10°C TO +70°C, 32.768 kHz XTAL, 2 x 22 pF, ALL PERIPHERALS DISABLED FIGURE 23-22: IPD SEC_IDLE MODE, -10°C TO +70°C, 32.768 kHz, 2 x 22 pF, ALL PERIPHERALS DISABLED 0 10 20 30 40 50 60 70 80 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Typ (+25°C) Max (+70°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0 2 4 6 8 10 12 14 16 18 20 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Typ (+25°C) Max (+70°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 278 © 2007 Microchip Technology Inc. FIGURE 23-23: TOTAL IPD, -40°C TO +125°C SLEEP MODE, ALL PERIPHERALS DISABLED FIGURE 23-24: VOH vs. IOH OVER TEMPERATURE (-40°C TO +125°C), VDD = 3.0V 0.001 0.01 0.1 1 10 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Max (+85°C) Max (+125°C) Typ (+25°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 5 10 15 20 25 IOH (-mA) VOH (V) Max (+125°C) Min (+125°C) Typ (+25°C)© 2007 Microchip Technology Inc. DS39605F-page 279 PIC18F1220/1320 FIGURE 23-25: VOH vs. IOH OVER TEMPERATURE (-40°C TO +125°C), VDD = 5.0V FIGURE 23-26: VOL vs. IOL OVER TEMPERATURE (-40°C TO +125°C), VDD = 3.0V 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 5 10 15 20 25 IOH (-mA) VOH (V) Max (+125°C) Min (+125°C) Typ (+25°C) V vs I over Temp (-40°C to +125°C) V = 3.0V 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 5 10 15 20 25 IOL (-mA) VOL (V) Max (+125°C) Max (+85°C) Typ (+25°C) Min (+125°C)PIC18F1220/1320 DS39605F-page 280 © 2007 Microchip Technology Inc. FIGURE 23-27: VOL vs. IOL OVER TEMPERATURE (-40°C TO +125°C), VDD = 5.0V FIGURE 23-28: ΔIPD TIMER1 OSCILLATOR, -10°C TO +70°C SLEEP MODE, TMR1 COUNTER DISABLED 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 5 10 15 20 25 IOL (-mA) VOL (V) Max (+125°C) Max (+85°C) Typ (+25°C) Min (+125°C) IPD Timer1 Oscillator, -10°C to +70°C SLEEP mode, TMR1 counter disabled 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Typ (+25°C) Max (-10°C to +70°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 281 PIC18F1220/1320 FIGURE 23-29: ΔIPD FSCM vs. VDD OVER TEMPERATURE PRI_IDLE MODE, EC OSCILLATOR AT 32 kHz, -40°C TO +125°C FIGURE 23-30: ΔIPD WDT, -40°C TO +125°C SLEEP MODE, ALL PERIPHERALS DISABLED 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) ΔIPD (μA) Typ (+25°C) Max (-40°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0 2 4 6 8 10 12 14 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) ΔIPD (μA) Typ (+25°C) Max (+85°C) Max (+125°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)PIC18F1220/1320 DS39605F-page 282 © 2007 Microchip Technology Inc. FIGURE 23-31: ΔIPD LVD vs. VDD SLEEP MODE, LVDL3:LVDL0 = 0001 (2V) FIGURE 23-32: ΔIPD BOR vs. VDD, -40°C TO +125°C SLEEP MODE, BORV1:BORV0 = 11 (2V) 0 5 10 15 20 25 30 35 40 45 50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Typ (+25°C) Max (+85°C) Max (+125°C) Low-Voltage Detection Range Normal Operating Range Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0 5 10 15 20 25 30 35 40 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Max (+125°C) Typ (+25°C) Device may be in Reset Device is Operating Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C)© 2007 Microchip Technology Inc. DS39605F-page 283 PIC18F1220/1320 FIGURE 23-33: ΔIPD A/D, -40°C TO +125°C SLEEP MODE, A/D ENABLED (NOT CONVERTING) FIGURE 23-34: AVERAGE FOSC vs. VDD FOR VARIOUS R’s EXTERNAL RC MODE, C = 20 pF, TEMPERATURE = +25°C 0.001 0.01 0.1 1 10 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Max (+125°C) Max (+85°C) Typ (+25°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to +125°C) Minimum: mean – 3σ (-40°C to +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (MHz) 5.1K 10K 33K 100K Operation above 4 MHz is not recomendedPIC18F1220/1320 DS39605F-page 284 © 2007 Microchip Technology Inc. FIGURE 23-35: AVERAGE FOSC vs. VDD FOR VARIOUS R’s EXTERNAL RC MODE, C = 100 pF, TEMPERATURE = +25°C FIGURE 23-36: AVERAGE FOSC vs. VDD FOR VARIOUS R’s EXTERNAL RC MODE, C = 300 pF, TEMPERATURE = +25°C 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (MHz) 5.1K 10K 33K 100K 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (MHz) 5.1K 10K 33K 100K© 2007 Microchip Technology Inc. DS39605F-page 285 PIC18F1220/1320 24.0 PACKAGING INFORMATION 24.1 Package Marking Information 18-Lead PDIP XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F1320-I/P 0710017 18-Lead SOIC XXXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXXXX YYWWNNN Example PIC18F1220- E/SO 0710017 20-Lead SSOP XXXXXXXXXXX XXXXXXXXXXX YYWWNNN Example PIC18F1220- E/SS 0710017 28-Lead QFN XXXXXXXX XXXXXXXX YYWWNNN Example 18F1320 -I/ML 0710017 Legend: XX...X Customer-specific information Y Year code (last digit of calendar year) YY Year code (last 2 digits of calendar year) WW Week code (week of January 1 is week ‘01’) NNN Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) * This package is Pb-free. The Pb-free JEDEC designator ( ) can be found on the outer packaging for this package. Note: In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. e3 e3 e3 e3 e3 e3PIC18F1220/1320 DS39605F-page 286 © 2007 Microchip Technology Inc. 24.2 Package Details The following sections give the technical details of the packages. 18-Lead Plastic Dual In-Line (P) – 300 mil Body [PDIP] Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. § Significant Characteristic. 3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" per side. 4. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Units INCHES Dimension Limits MIN NOM MAX Number of Pins N 18 Pitch e .100 BSC Top to Seating Plane A – – .210 Molded Package Thickness A2 .115 .130 .195 Base to Seating Plane A1 .015 – – Shoulder to Shoulder Width E .300 .310 .325 Molded Package Width E1 .240 .250 .280 Overall Length D .880 .900 .920 Tip to Seating Plane L .115 .130 .150 Lead Thickness c .008 .010 .014 Upper Lead Width b1 .045 .060 .070 Lower Lead Width b .014 .018 .022 Overall Row Spacing § eB – – .430 NOTE 1 N E1 D 1 2 3 A A1 A2 L E eB c e b1 b Microchip Technology Drawing C04-007B© 2007 Microchip Technology Inc. DS39605F-page 287 PIC18F1220/1320 18-Lead Plastic Small Outline (SO) – Wide, 7.50 mm Body [SOIC] Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. § Significant Characteristic. 3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.15 mm per side. 4. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Units MILLIMETERS Dimension Limits MIN NOM MAX Number of Pins N 18 Pitch e 1.27 BSC Overall Height A – – 2.65 Molded Package Thickness A2 2.05 – – Standoff § A1 0.10 – 0.30 Overall Width E 10.30 BSC Molded Package Width E1 7.50 BSC Overall Length D 11.55 BSC Chamfer (optional) h 0.25 – 0.75 Foot Length L 0.40 – 1.27 Footprint L1 1.40 REF Foot Angle φ 0° – 8° Lead Thickness c 0.20 – 0.33 Lead Width b 0.31 – 0.51 Mold Draft Angle Top α 5° – 15° Mold Draft Angle Bottom β 5° – 15° NOTE 1 D N E E1 e b 1 2 3 A A1 A2 L L1 h h c β φ α Microchip Technology Drawing C04-051BPIC18F1220/1320 DS39605F-page 288 © 2007 Microchip Technology Inc. 20-Lead Plastic Shrink Small Outline (SS) – 5.30 mm Body [SSOP] Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.20 mm per side. 3. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Units MILLIMETERS Dimension Limits MIN NOM MAX Number of Pins N 20 Pitch e 0.65 BSC Overall Height A – – 2.00 Molded Package Thickness A2 1.65 1.75 1.85 Standoff A1 0.05 – – Overall Width E 7.40 7.80 8.20 Molded Package Width E1 5.00 5.30 5.60 Overall Length D 6.90 7.20 7.50 Foot Length L 0.55 0.75 0.95 Footprint L1 1.25 REF Lead Thickness c 0.09 – 0.25 Foot Angle φ 0° 4° 8° Lead Width b 0.22 – 0.38 φ L1 L A2 c e b A1 A 1 2 NOTE 1 E1 E D N Microchip Technology Drawing C04-072B© 2007 Microchip Technology Inc. DS39605F-page 289 PIC18F1220/1320 28-Lead Plastic Quad Flat, No Lead Package (ML) – 6x6 mm Body [QFN] with 0.55 mm Contact Length Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. Package is saw singulated. 3. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Units MILLIMETERS Dimension Limits MIN NOM MAX Number of Pins N 28 Pitch e 0.65 BSC Overall Height A 0.80 0.90 1.00 Standoff A1 0.00 0.02 0.05 Contact Thickness A3 0.20 REF Overall Width E 6.00 BSC Exposed Pad Width E2 3.65 3.70 4.20 Overall Length D 6.00 BSC Exposed Pad Length D2 3.65 3.70 4.20 Contact Width b 0.23 0.30 0.35 Contact Length L 0.50 0.55 0.70 Contact-to-Exposed Pad K 0.20 – – D EXPOSED D2 e b K E2 E L N NOTE 1 1 2 2 1 N A A3 A1 TOP VIEW BOTTOM VIEW PAD Microchip Technology Drawing C04-105BPIC18F1220/1320 DS39605F-page 290 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 291 PIC18F1220/1320 APPENDIX A: REVISION HISTORY Revision A (August 2002) Original data sheet for PIC18F1220/1320 devices. Revision B (November 2002) This revision includes significant changes to Section 2.0, Section 3.0 and Section 19.0, as well as updates to the Electrical Specifications in Section 22.0 and includes minor corrections to the data sheet text. Revision C (May 2004) This revision includes updates to the Electrical Specifications in Section 22.0, the DC and AC Characteristics Graphs and Tables in Section 23.0 and includes minor corrections to the data sheet text. Revision D (October 2006) This revision includes updates to the packaging diagrams. Revision E (January 2007) This revision includes updates to the packaging diagrams. Revision F (February 2007) This revision includes updates to the packaging diagrams. APPENDIX B: DEVICE DIFFERENCES The differences between the devices listed in this data sheet are shown in Table B-1. TABLE B-1: DEVICE DIFFERENCES Features PIC18F1220 PIC18F1320 Program Memory (Bytes) 4096 8192 Program Memory (Instructions) 2048 4096 Interrupt Sources 15 15 I/O Ports Ports A, B Ports A, B Enhanced Capture/Compare/PWM Modules 1 1 10-bit Analog-to-Digital Module 7 input channels 7 input channels Packages 18-pin SDIP 18-pin SOIC 20-pin SSOP 28-pin QFN 18-pin SDIP 18-pin SOIC 20-pin SSOP 28-pin QFNPIC18F1220/1320 DS39605F-page 292 © 2007 Microchip Technology Inc. APPENDIX C: CONVERSION CONSIDERATIONS This appendix discusses the considerations for converting from previous versions of a device to the ones listed in this data sheet. Typically, these changes are due to the differences in the process technology used. An example of this type of conversion is from a PIC16C74A to a PIC16C74B. Not Applicable APPENDIX D: MIGRATION FROM BASELINE TO ENHANCED DEVICES This section discusses how to migrate from a baseline device (i.e., PIC16C5X) to an enhanced MCU device (i.e., PIC18FXXX). The following are the list of modifications over the PIC16C5X microcontroller family: Not Currently Available© 2007 Microchip Technology Inc. DS39605F-page 293 PIC18F1220/1320 APPENDIX E: MIGRATION FROM MID-RANGE TO ENHANCED DEVICES A detailed discussion of the differences between the mid-range MCU devices (i.e., PIC16CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN716, “Migrating Designs from PIC16C74A/74B to PIC18C442”. The changes discussed, while device specific, are generally applicable to all mid-range to enhanced device migrations. This Application Note is available as Literature Number DS00716. APPENDIX F: MIGRATION FROM HIGH-END TO ENHANCED DEVICES A detailed discussion of the migration pathway and differences between the high-end MCU devices (i.e., PIC17CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN726, “PIC17CXXX to PIC18CXXX Migration”. This Application Note is available as Literature Number DS00726.PIC18F1220/1320 DS39605F-page 294 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 295 PIC18F1220/1320 INDEX A A/D ................................................................................... 155 A/D Converter Interrupt, Configuring ....................... 159 Acquisition Requirements ........................................ 160 ADCON0 Register .................................................... 155 ADCON1 Register .................................................... 155 ADCON2 Register .................................................... 155 ADRESH Register .................................................... 155 ADRESH/ADRESL Registers .................................. 158 ADRESL Register .................................................... 155 Analog Port Pins, Configuring .................................. 162 Associated Registers ............................................... 164 Configuring the Module ............................................ 159 Conversion Clock (Tad) ........................................... 161 Conversion Requirements ....................................... 265 Conversion Status (GO/DONE Bit) .......................... 158 Conversions ............................................................. 163 Converter Characteristics ........................................ 264 Operation in Low-Power Modes ............................... 162 Selecting, Configuring Automatic Acquisition Time ............................................... 161 Special Event Trigger (CCP) .................................... 117 Special Event Trigger (CCP1) .................................. 164 Use of the CCP1 Trigger .......................................... 164 Vref+ and Vref- References ..................................... 160 Absolute Maximum Ratings ............................................. 237 AC (Timing) Characteristics ............................................. 255 Conditions ................................................................ 256 Load Conditions for Device Timing Specifications ....................................... 256 Parameter Symbology ............................................. 255 Temperature and Voltage Specifications ................. 256 ADCON0 Register ............................................................ 155 GO/DONE Bit ........................................................... 158 ADCON1 Register ............................................................ 155 ADCON2 Register ............................................................ 155 ADDLW ............................................................................ 197 ADDWF ............................................................................ 197 ADDWFC ......................................................................... 198 ADRESH Register ............................................................ 155 ADRESH/ADRESL Registers ........................................... 158 ADRESL Register ............................................................ 155 Analog-to-Digital Converter. See A/D. ANDLW ............................................................................ 198 ANDWF ............................................................................ 199 Assembler MPASM Assembler .................................................. 234 Auto-Wake-up on Sync Break Character ......................... 145 B BC .................................................................................... 199 BCF .................................................................................. 200 Block Diagrams A/D ........................................................................... 158 Analog Input Model .................................................. 159 Capture Mode Operation ......................................... 117 Compare Mode Operation ....................................... 118 Enhanced PWM ....................................................... 120 EUSART Receive .................................................... 143 EUSART Transmit ................................................... 141 Fail-Safe Clock Monitor ............................................ 182 Generic I/O Port Operation ........................................ 87 Low-Voltage Detect (LVD) ....................................... 166 Low-Voltage Detect (LVD) with External Input ........ 166 MCLR/VPP/RA5 Pin ................................................... 89 On-Chip Reset Circuit ................................................ 33 OSC1/CLKI/RA7 Pin .................................................. 88 OSC2/CLKO/RA6 Pin ................................................ 88 PIC18F1220/1320 ....................................................... 7 PLL ............................................................................ 12 RA3:RA0 Pins ............................................................ 88 RA4/T0CKI Pin .......................................................... 88 RB0/AN4/INT0 Pin ..................................................... 90 RB1/AN5/TX/CK/INT1 Pin ......................................... 91 RB2/P1B/INT2 Pin ..................................................... 92 RB3/CCP1/P1A Pin ................................................... 93 RB4/AN6/RX/DT/KBI0 Pin ......................................... 94 RB5/PGM/KBI1 Pin .................................................... 95 RB6/PGC/T1OSO/T13CKI/P1C/KBI2 Pin .................. 96 RB7/PGD/T1OSI/P1D/KBI3 Pin ................................. 97 Reads from Flash Program Memory .......................... 61 System Clock ............................................................. 16 Table Read Operation ............................................... 57 Table Write Operation ................................................ 58 Table Writes to Flash Program Memory .................... 63 Timer0 in 16-Bit Mode ............................................. 100 Timer0 in 8-Bit Mode ............................................... 100 Timer1 ..................................................................... 104 Timer1 (16-Bit Read/Write Mode) ............................ 104 Timer2 ..................................................................... 110 Timer3 ..................................................................... 112 Timer3 (16-bit Read/Write Mode) ............................ 112 WDT ........................................................................ 180 BN .................................................................................... 200 BNC ................................................................................. 201 BNN ................................................................................. 201 BNOV ............................................................................... 202 BNZ .................................................................................. 202 BOR. See Brown-out Reset. BOV ................................................................................. 205 BRA ................................................................................. 203 Break Character (12-bit) Transmit and Receive .............. 146 Brown-out Reset (BOR) ..............................................34, 171 BSF .................................................................................. 203 BTFSC ............................................................................. 204 BTFSS ............................................................................. 204 BTG ................................................................................. 205 BZ .................................................................................... 206 C C Compilers MPLAB C18 ............................................................. 234 MPLAB C30 ............................................................. 234 CALL ................................................................................ 206 Capture (CCP Module) .................................................... 116 CCP Pin Configuration ............................................. 116 CCPR1H:CCPR1L Registers ................................... 116 Software Interrupt .................................................... 116 Timer1/Timer3 Mode Selection ................................ 116 Capture, Compare, Timer1 and Timer3 Associated Registers ............................................... 118PIC18F1220/1320 DS39605F-page 296 © 2007 Microchip Technology Inc. Capture/Compare/PWM (CCP) Capture Mode. See Capture. CCP1 ........................................................................116 CCPR1H Register ............................................ 116 CCPR1L Register ............................................ 116 Compare Mode. See Compare. Timer Resources ...................................................... 116 Clock Sources .................................................................... 15 Selection Using OSCCON Register ........................... 16 Clocking Scheme ............................................................... 45 CLRF ................................................................................ 207 CLRWDT .......................................................................... 207 Code Examples 16 x 16 Signed Multiply Routine ................................. 72 16 x 16 Unsigned Multiply Routine ............................. 72 8 x 8 Signed Multiply Routine ..................................... 71 8 x 8 Unsigned Multiply Routine ................................. 71 Changing Between Capture Prescalers ................... 117 Computed GOTO Using an Offset Value ................... 47 Data EEPROM Read .................................................69 Data EEPROM Refresh Routine ................................70 Data EEPROM Write .................................................. 69 Erasing a Flash Program Memory Row ..................... 62 Fast Register Stack .................................................... 44 How to Clear RAM (Bank 1) Using Indirect Addressing ............................................ 53 Implementing a Real-Time Clock Using a Timer1 Interrupt Service .................................. 107 Initializing PORTA ...................................................... 87 Initializing PORTB ...................................................... 90 Reading a Flash Program Memory Word ................... 61 Saving Status, WREG and BSR Registers in RAM ....................................... 85 Writing to Flash Program Memory ....................... 64–65 Code Protection ............................................................... 171 COMF ............................................................................... 208 Compare (CCP Module) ...................................................117 CCP Pin Configuration ............................................. 117 CCPR1 Register ....................................................... 117 Software Interrupt ..................................................... 117 Special Event Trigger ....................................... 113, 117 Timer1/Timer3 Mode Selection ................................ 117 Compare (CCP1 Module) Special Event Trigger ...............................................164 Computed GOTO ............................................................... 47 Configuration Bits ............................................................. 171 Context Saving During Interrupts ....................................... 85 Conversion Considerations .............................................. 292 CPFSEQ .......................................................................... 208 CPFSGT ........................................................................... 209 CPFSLT ........................................................................... 209 Customer Change Notification Service ............................302 Customer Notification Service .......................................... 302 Customer Support ............................................................ 302 D Data EEPROM Memory .....................................................67 Associated Registers .................................................70 EEADR Register ........................................................ 67 EECON1 Register ...................................................... 67 EECON2 Register ...................................................... 67 Operation During Code-Protect .................................. 70 Protection Against Spurious Write ............................. 69 Reading ......................................................................69 Using ..........................................................................70 Write Verify ................................................................. 69 Writing ........................................................................69 Data Memory ..................................................................... 47 General Purpose Registers ....................................... 47 Map for PIC18F1220/1320 Devices ........................... 48 Special Function Registers ........................................ 49 DAW ................................................................................ 210 DC and AC Characteristics Graphs and Tables .................................................. 267 DC Characteristics ........................................................... 250 Power-Down and Supply Current ............................ 241 Supply Voltage ......................................................... 240 DCFSNZ .......................................................................... 211 DECF ............................................................................... 210 DECFSZ .......................................................................... 211 Details on Individual Family Members ................................. 6 Development Support ...................................................... 233 Device Differences ........................................................... 291 Direct Addressing ............................................................... 54 E Effects of Power Managed Modes on Various Clock Sources .............................................. 18 Electrical Characteristics .................................................. 237 Enhanced Capture/Compare/PWM (ECCP) .................... 115 Outputs .................................................................... 116 PWM Mode. See PWM (ECCP Module). Enhanced PWM Mode. See PWM (ECCP Module). ........ 119 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................. 131 Equations 16 x 16 Signed Multiplication Algorithm ..................... 72 16 x 16 Unsigned Multiplication Algorithm ................. 72 A/D Minimum Charging Time ................................... 160 Acquisition Time ...................................................... 160 Errata ................................................................................... 4 EUSART Asynchronous Mode ................................................ 140 12-bit Break Transmit and Receive ................. 146 Associated Registers, Receive ........................ 144 Associated Registers, Transmit ....................... 142 Auto-Wake-up on Sync Break ......................... 145 Receiver .......................................................... 143 Setting up 9-bit Mode with Address Detect ........................................ 143 Transmitter ....................................................... 140 Baud Rate Generator (BRG) ................................... 135 Associated Registers ....................................... 136 Auto-Baud Rate Detect .................................... 139 Baud Rate Error, Calculating ........................... 135 Baud Rates, Asynchronous Modes ................. 136 High Baud Rate Select (BRGH Bit) ................. 135 Power Managed Mode Operation .................... 135 Sampling .......................................................... 135 Serial Port Enable (SPEN Bit) ................................. 131 Synchronous Master Mode ...................................... 148 Associated Registers, Reception ..................... 151 Associated Registers, Transmit ....................... 149 Reception ........................................................ 150 Transmission ................................................... 148 Synchronous Slave Mode ........................................ 152 Associated Registers, Receive ........................ 153 Associated Registers, Transmit ....................... 152 Reception ........................................................ 153 Transmission ................................................... 152© 2007 Microchip Technology Inc. DS39605F-page 297 PIC18F1220/1320 F Fail-Safe Clock Monitor .................................................... 171 Exiting Operation ..................................................... 183 Interrupts in Power Managed Modes ....................... 183 POR or Wake from Sleep ........................................ 184 WDT During Oscillator Failure ................................. 182 Fail-Safe Clock Monitor (FSCM) ...................................... 182 Fast Register Stack ............................................................ 44 Firmware Instructions ....................................................... 191 Flash Program Memory ...................................................... 57 Associated Registers ................................................. 65 Control Registers ....................................................... 58 Erase Sequence ........................................................ 62 Erasing ....................................................................... 62 Operation During Code-Protect ................................. 65 Reading ...................................................................... 61 Table Latch ................................................................ 60 Table Pointer .............................................................. 60 Boundaries Based on Operation ........................ 60 Table Pointer Boundaries .......................................... 60 Table Reads and Table Writes .................................. 57 Write Sequence ......................................................... 63 Writing to .................................................................... 63 Unexpected Termination .................................... 65 Write Verify ........................................................ 65 G GOTO ............................................................................... 212 H Hardware Multiplier ............................................................ 71 Introduction ................................................................ 71 Operation ................................................................... 71 Performance Comparison .......................................... 71 I I/O Ports ............................................................................. 87 ID Locations ............................................................. 171, 188 INCF ................................................................................. 212 INCFSZ ............................................................................ 213 In-Circuit Debugger .......................................................... 188 In-Circuit Serial Programming (ICSP) ...................... 171, 188 Indirect Addressing ............................................................ 54 INDF and FSR Registers ........................................... 53 Operation ................................................................... 53 Indirect Addressing Operation ............................................ 54 Indirect File Operand .......................................................... 47 INFSNZ ............................................................................ 213 Initialization Conditions for All Registers ...................... 36–38 Instruction Cycle ................................................................. 45 Instruction Flow/Pipelining ................................................. 45 Instruction Set .................................................................. 191 ADDLW .................................................................... 197 ADDWF .................................................................... 197 ADDWFC ................................................................. 198 ANDLW .................................................................... 198 ANDWF .................................................................... 199 BC ............................................................................ 199 BCF .......................................................................... 200 BN ............................................................................ 200 BNC ......................................................................... 201 BNN ......................................................................... 201 BNOV ....................................................................... 202 BNZ .......................................................................... 202 BOV ......................................................................... 205 BRA ......................................................................... 203 BSF .......................................................................... 203 BTFSC ..................................................................... 204 BTFSS ..................................................................... 204 BTG ......................................................................... 205 BZ ............................................................................ 206 CALL ........................................................................ 206 CLRF ....................................................................... 207 CLRWDT ................................................................. 207 COMF ...................................................................... 208 CPFSEQ .................................................................. 208 CPFSGT .................................................................. 209 CPFSLT ................................................................... 209 DAW ........................................................................ 210 DCFSNZ .................................................................. 211 DECF ....................................................................... 210 DECFSZ .................................................................. 211 General Format ........................................................ 193 GOTO ...................................................................... 212 INCF ........................................................................ 212 INCFSZ .................................................................... 213 INFSNZ .................................................................... 213 IORLW ..................................................................... 214 IORWF ..................................................................... 214 LFSR ....................................................................... 215 MOVF ...................................................................... 215 MOVFF .................................................................... 216 MOVLB .................................................................... 216 MOVLW ................................................................... 217 MOVWF ................................................................... 217 MULLW .................................................................... 218 MULWF .................................................................... 218 NEGF ....................................................................... 219 NOP ......................................................................... 219 POP ......................................................................... 220 PUSH ....................................................................... 220 RCALL ..................................................................... 221 RESET ..................................................................... 221 RETFIE .................................................................... 222 RETLW .................................................................... 222 RETURN .................................................................. 223 RLCF ....................................................................... 223 RLNCF ..................................................................... 224 RRCF ....................................................................... 224 RRNCF .................................................................... 225 SETF ....................................................................... 225 SLEEP ..................................................................... 226 SUBFWB ................................................................. 226 SUBLW .................................................................... 227 SUBWF .................................................................... 227 SUBWFB ................................................................. 228 SWAPF .................................................................... 228 TBLRD ..................................................................... 229 TBLWT .................................................................... 230 TSTFSZ ................................................................... 231 XORLW ................................................................... 231 XORWF ................................................................... 232 Summary Table ....................................................... 194 INTCON Register RBIF Bit ..................................................................... 90 INTCON Registers ............................................................. 75PIC18F1220/1320 DS39605F-page 298 © 2007 Microchip Technology Inc. Internal Oscillator Block .....................................................14 Adjustment ................................................................. 14 INTIO Modes .............................................................. 14 INTRC Output Frequency .......................................... 14 OSCTUNE Register ...................................................14 Internal RC Oscillator Use with WDT .......................................................... 180 Internet Address ............................................................... 302 Interrupt Sources .............................................................. 171 A/D Conversion Complete ........................................ 159 Capture Complete (CCP) ......................................... 116 Compare Complete (CCP) ....................................... 117 Interrupt-on-Change (RB7:RB4) ................................90 INTn Pin ..................................................................... 85 PORTB, Interrupt-on-Change .................................... 85 TMR0 ......................................................................... 85 TMR0 Overflow ........................................................ 101 TMR1 Overflow ........................................................ 103 TMR2 to PR2 Match .................................................110 TMR2 to PR2 Match (PWM) ............................ 109, 119 TMR3 Overflow ................................................ 111, 113 Interrupts ............................................................................ 73 Enable Bits (CCP1IE Bit) .................................................... 116 Flag Bits CCP1 Flag (CCP1IF Bit) .................................. 116 CCP1IF Flag (CCP1IF Bit) ............................... 117 Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ........................................... 90 Logic ........................................................................... 74 INTOSC Frequency Drift .................................................... 30 IORLW ............................................................................. 214 IORWF ............................................................................. 214 IPR Registers ..................................................................... 82 L LFSR ................................................................................ 215 Low-Voltage Detect .......................................................... 165 Characteristics ......................................................... 253 Effects of a Reset ..................................................... 169 Operation ................................................................. 168 Current Consumption ....................................... 169 Reference Voltage Set Point ............................169 Operation During Sleep ............................................ 169 LVD. See Low-Voltage Detect. ........................................ 165 M Memory Organization ......................................................... 41 Data Memory .............................................................. 47 Program Memory ....................................................... 41 Memory Programming Requirements ..............................252 Microchip Internet Web Site ............................................. 302 Migration from Baseline to Enhanced Devices ................ 292 Migration from High-End to Enhanced Devices ............... 293 Migration from Mid-Range to Enhanced Devices ............. 293 MOVF ............................................................................... 215 MOVFF ............................................................................. 216 MOVLB ............................................................................. 216 MOVLW ............................................................................ 217 MOVWF ........................................................................... 217 MPLAB ASM30 Assembler, Linker, Librarian .................. 234 MPLAB ICD 2 In-Circuit Debugger ................................... 235 MPLAB ICE 2000 High-Performance Universal In-Circuit Emulator ................................... 235 MPLAB Integrated Development Environment Software .............................................. 233 MPLAB PM3 Device Programmer ................................... 235 MPLAB REAL ICE In-Circuit Emulator System ................ 235 MPLINK Object Linker/MPLIB Object Librarian ............... 234 MULLW ............................................................................ 218 MULWF ............................................................................ 218 N NEGF ............................................................................... 219 New Core Features Multiple Oscillator Options and Features ..................... 5 nanoWatt Technology .................................................. 5 NOP ................................................................................. 219 O Opcode Field Descriptions ............................................... 192 OPTION_REG Register PSA Bit .................................................................... 101 T0CS Bit .................................................................. 101 T0PS2:T0PS0 Bits ................................................... 101 T0SE Bit ................................................................... 101 Oscillator Configuration ...................................................... 11 Crystal/Ceramic Resonator ........................................ 11 EC .............................................................................. 11 ECIO .......................................................................... 11 External Clock Input ................................................... 13 HS .............................................................................. 11 HSPLL ..................................................................11, 12 INTIO1 ....................................................................... 11 INTIO2 ....................................................................... 11 LP .............................................................................. 11 RC .........................................................................11, 13 RCIO .......................................................................... 11 XT .............................................................................. 11 Oscillator Selection .......................................................... 171 Oscillator Start-up Timer (OST) ............................18, 34, 171 Oscillator Switching ............................................................ 15 Oscillator Transitions ......................................................... 18 Oscillator, Timer1 ......................................................103, 113 Oscillator, Timer3 ............................................................. 111 Other Special Features ........................................................ 5 P Packaging ........................................................................ 285 Details ...................................................................... 286 Marking Information ................................................. 285 PICSTART Plus Development Programmer .................... 236 PIE Registers ..................................................................... 80 Pin Functions MCLR/Vpp/RA5 ........................................................... 8 OSC1/CLKI/RA7 .......................................................... 8 OSC2/CLKO/RA6 ........................................................ 8 RA0/AN0 ...................................................................... 8 RA1/AN1/LVDIN .......................................................... 8 RA2/AN2/Vref- ............................................................. 8 RA3/AN3/VREF+ ........................................................... 8 RA4/T0CKI ................................................................... 8 RB0/AN4/INT0 ............................................................. 9 RB1/AN5/TX/CK/INT1 ................................................. 9 RB2/P1B/INT2 ............................................................. 9 RB3/CCP1/P1A ........................................................... 9 RB4/AN6/RX/DT/KBI0 ................................................. 9 RB5/PGM/KBI1 ............................................................ 9 RB6/PGC/T1OSO/T13CKI/P1C/KBI2 .......................... 9 RB7/PGD/T1OSI/P1D/KBI3 ......................................... 9 Vdd .............................................................................. 9 Vss ............................................................................... 9© 2007 Microchip Technology Inc. DS39605F-page 299 PIC18F1220/1320 Pinout I/O Descriptions PIC18F1220/1320 ........................................................ 8 PIR Registers ..................................................................... 78 PLL Lock Time-out ............................................................. 34 Pointer, FSR ....................................................................... 53 POP .................................................................................. 220 POR. See Power-on Reset. PORTA Associated Registers ................................................. 89 Functions ................................................................... 89 LATA Register ............................................................ 87 PORTA Register ........................................................ 87 TRISA Register .......................................................... 87 PORTB Associated Registers ................................................. 98 Functions ................................................................... 98 LATB Register ............................................................ 90 PORTB Register ........................................................ 90 RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) ........................................................... 90 TRISB Register .......................................................... 90 Postscaler Timer2 ...................................................................... 109 WDT Assignment (PSA Bit) ...................................... 101 Rate Select (T0PS2:T0PS0 Bits) ..................... 101 Power Managed Modes ..................................................... 19 Comparison between Run and Idle Modes ................ 20 Entering ...................................................................... 20 Idle Modes ................................................................. 21 Multiple Sleep Commands ......................................... 20 Run Modes ................................................................. 26 Selecting .................................................................... 19 Sleep Mode ................................................................ 21 Summary (table) ........................................................ 19 Wake from .................................................................. 28 Power-on Reset (POR) .............................................. 34, 171 Power-up Delays ................................................................ 18 Power-up Timer (PWRT) .......................................18, 34, 171 Prescaler Capture .................................................................... 117 Timer0 ...................................................................... 101 Assignment (PSA Bit) ...................................... 101 Rate Select (T0PS2:T0PS0 Bits) ..................... 101 Timer2 ...................................................................... 119 Product Identification System ........................................... 304 Program Counter PCL Register .............................................................. 44 PCLATH Register ...................................................... 44 PCLATU Register ...................................................... 44 Program Memory Instructions in ............................................................. 46 Interrupt Vector .......................................................... 41 Map and Stack for PIC18F1220 ................................. 41 Map and Stack for PIC18F1320 ................................. 41 Reset Vector .............................................................. 41 Program Verification and Code Protection ....................... 185 Associated Registers ............................................... 185 Configuration Register ............................................. 188 Data EEPROM ......................................................... 188 Program Memory ..................................................... 186 Programming, Device Instructions ................................... 191 PUSH ............................................................................... 220 PUSH and POP Instructions .............................................. 43 PWM (CCP Module) CCPR1H:CCPR1L Registers ................................... 119 Duty Cycle ............................................................... 119 Example Frequencies/Resolutions .......................... 119 Period ...................................................................... 119 TMR2 to PR2 Match .........................................109, 119 PWM (ECCP Module) ...................................................... 119 Associated Registers ............................................... 130 Direction Change in Full-Bridge Output Mode ......... 124 Effects of a Reset .................................................... 129 Enhanced PWM Auto-Shutdown ............................. 126 Full-Bridge Application Example .............................. 124 Full-Bridge PWM Output (Active-High) Diagram ..... 123 Half-Bridge Output (Active-High) Diagram ............... 122 Half-Bridge Output Mode Applications Example ...... 122 Operation in Low-Power Modes .............................. 129 Output Configurations .............................................. 119 Output Relationships (Active-High) .......................... 120 Output Relationships (Active-Low) .......................... 121 Programmable Dead-Band Delay ............................ 126 PWM Direction Change (Active-High) Diagram ....... 125 PWM Direction Change at Near 100% Duty Cycle (Active-High) Diagram ......... 125 Setup for PWM Operation ........................................ 129 Start-up Considerations ........................................... 128 Q Q Clock ............................................................................ 119 R RAM. See Data Memory. RCALL ............................................................................. 221 RCIO Oscillator .................................................................. 13 RCON Register Bit Status During Initialization .................................... 35 RCSTA Register SPEN Bit .................................................................. 131 Reader Response ............................................................ 303 Register File ....................................................................... 47 Register File Summary .................................................50–51 Registers ADCON0 (A/D Control 0) ......................................... 155 ADCON1 (A/D Control 1) ......................................... 156 ADCON2 (A/D Control 2) ......................................... 157 BAUDCTL (Baud Rate Control) ............................... 134 CCP1CON (Enhanced CCP1 Control) .................... 115 CONFIG1H (Configuration 1 High) .......................... 172 CONFIG2H (Configuration 2 High) .......................... 174 CONFIG2L (Configuration 2 Low) ........................... 173 CONFIG3H (Configuration 3 High) .......................... 175 CONFIG4L (Configuration 4 Low) ........................... 175 CONFIG5H (Configuration 5 High) .......................... 176 CONFIG5L (Configuration 5 Low) ........................... 176 CONFIG6H (Configuration 6 High) .......................... 177 CONFIG6L (Configuration 6 Low) ........................... 177 CONFIG7H (Configuration 7 High) .......................... 178 CONFIG7L (Configuration 7 Low) ........................... 178 DEVID1 (Device ID 1) .............................................. 179 DEVID2 (Device ID 2) .............................................. 179 ECCPAS (ECCP Auto-Shutdown Control) .............. 127 EECON1 (Data EEPROM Control 1) ....................59, 68 INTCON (Interrupt Control) ........................................ 75 INTCON2 (Interrupt Control 2) ................................... 76 INTCON3 (Interrupt Control 3) ................................... 77 IPR1 (Peripheral Interrupt Priority 1) ......................... 82 IPR2 (Peripheral Interrupt Priority 2) ......................... 83 LVDCON (LVD Control) ........................................... 167 OSCCON (Oscillator Control) .................................... 17PIC18F1220/1320 DS39605F-page 300 © 2007 Microchip Technology Inc. OSCTUNE (Oscillator Tuning) ................................... 15 PIE1 (Peripheral Interrupt Enable 1) .......................... 80 PIE2 (Peripheral Interrupt Enable 2) .......................... 81 PIR1 (Peripheral Interrupt Request (Flag) 1) ............. 78 PIR2 (Peripheral Interrupt Request (Flag) 2) ............. 79 PWM1CON (PWM Configuration) ............................126 RCON (Reset Control) ......................................... 56, 84 RCSTA (Receive Status and Control) ...................... 133 Status ......................................................................... 55 STKPTR (Stack Pointer) ............................................ 43 T0CON (Timer0 Control) ............................................ 99 T1CON (Timer 1 Control) ......................................... 103 T2CON (Timer 2 Control) ......................................... 109 T3CON (Timer3 Control) .......................................... 111 TXSTA (Transmit Status and Control) ..................... 132 WDTCON (Watchdog Timer Control) ....................... 180 RESET ............................................................................. 221 Reset .......................................................................... 33, 171 RETFIE ............................................................................ 222 RETLW ............................................................................. 222 RETURN .......................................................................... 223 Return Address Stack ........................................................ 42 and Associated Registers .......................................... 42 Return Stack Pointer (STKPTR) ........................................ 42 Revision History ............................................................... 291 RLCF ................................................................................ 223 RLNCF ............................................................................. 224 RRCF ............................................................................... 224 RRNCF ............................................................................. 225 S SETF ................................................................................ 225 SLEEP .............................................................................. 226 Sleep OSC1 and OSC2 Pin States ...................................... 18 Software Simulator (MPLAB SIM) .................................... 234 Special Event Trigger. See Compare Special Features of the CPU ............................................ 171 Configuration Registers .................................... 172–178 Special Function Registers ................................................ 49 Map ............................................................................ 49 Stack Full/Underflow Resets .............................................. 43 SUBFWB .......................................................................... 226 SUBLW ............................................................................ 227 SUBWF ............................................................................ 227 SUBWFB .......................................................................... 228 SWAPF ............................................................................ 228 T TABLAT Register ............................................................... 60 Table Pointer Operations (table) ........................................ 60 TBLPTR Register ............................................................... 60 TBLRD ............................................................................. 229 TBLWT ............................................................................. 230 Time-out Sequence ............................................................ 34 Timer0 ................................................................................ 99 16-Bit Mode Timer Reads and Writes ...................... 101 Associated Registers ...............................................101 Clock Source Edge Select (T0SE Bit) ...................... 101 Clock Source Select (T0CS Bit) ............................... 101 Operation ................................................................. 101 Overflow Interrupt ..................................................... 101 Prescaler. See Prescaler, Timer0. Switching Prescaler Assignment ..............................101 Timer1 .............................................................................. 103 16-Bit Read/Write Mode .......................................... 106 Associated Registers ............................................... 108 Interrupt ................................................................... 106 Operation ................................................................. 104 Oscillator ...........................................................103, 105 Layout Considerations ..................................... 106 Overflow Interrupt .................................................... 103 Resetting, Using a Special Event Trigger Output (CCP) ................................................... 106 Special Event Trigger (CCP) ................................... 117 TMR1H Register ...................................................... 103 TMR1L Register ....................................................... 103 Use as a Real-Time Clock ....................................... 107 Timer2 .............................................................................. 109 Associated Registers ............................................... 110 Operation ................................................................. 109 Output ...................................................................... 110 Postscaler. See Postscaler, Timer2. PR2 Register ....................................................109, 119 Prescaler. See Prescaler, Timer2. TMR2 Register ......................................................... 109 TMR2 to PR2 Match Interrupt ...................109, 110, 119 Timer3 .............................................................................. 111 Associated Registers ............................................... 113 Operation ................................................................. 112 Oscillator ...........................................................111, 113 Overflow Interrupt .............................................111, 113 Special Event Trigger (CCP) ................................... 113 TMR3H Register ...................................................... 111 TMR3L Register ....................................................... 111 Timing Diagrams A/D Conversion ........................................................ 265 Asynchronous Reception ......................................... 144 Asynchronous Transmission .................................... 141 Asynchronous Transmission (Back to Back) ........... 142 Auto-Wake-up Bit (WUE) During Normal Operation ............................................ 145 Auto-Wake-up Bit (WUE) During Sleep ................... 145 Brown-out Reset (BOR) ........................................... 260 Capture/Compare/PWM (All CCP Modules) ............ 262 CLKO and I/O .......................................................... 259 Clock/Instruction Cycle .............................................. 45 EUSART Synchronous Receive (Master/Slave) ................................................. 264 EUSART SynchronousTransmission (Master/Slave) ................................................. 263 External Clock (All Modes Except PLL) ................... 257 Fail-Safe Clock Monitor ........................................... 183 Low-Voltage Detect ................................................. 168 Low-Voltage Detect Characteristics ......................... 253 PWM Auto-Shutdown (PRSEN = 0, Auto-Restart Disabled) .................................... 128 PWM Auto-Shutdown (PRSEN = 1, Auto-Restart Enabled) ..................................... 128 Reset, Watchdog Timer (WDT), Oscillator Start-up Timer (OST) and Power-up Timer (PWRT) ..... 260 Send Break Character Sequence ............................ 147 Slow Rise Time (MCLR Tied to VDD, VDD Rise > TPWRT) ............................................ 40 Synchronous Reception (Master Mode, SREN) ..................................... 150 Synchronous Transmission ..................................... 148 Synchronous Transmission (Through TXEN) .......... 149© 2007 Microchip Technology Inc. DS39605F-page 301 PIC18F1220/1320 Time-out Sequence on POR w/PLL Enabled (MCLR Tied to VDD) ........................................... 40 Time-out Sequence on Power-up (MCLR Not Tied to Vdd), Case 1 ....................... 39 Time-out Sequence on Power-up (MCLR Not Tied to Vdd), Case 2 ....................... 39 Time-out Sequence on Power-up (MCLR Tied to Vdd, Vdd Rise pwrt) ................... 39 Timer0 and Timer1 External Clock .......................... 261 Transition for Entry to SEC_IDLE Mode .................... 24 Transition for Entry to SEC_RUN Mode .................... 26 Transition for Entry to Sleep Mode ............................ 22 Transition for Two-Speed Start-up (INTOSC to HSPLL) ......................................... 181 Transition for Wake from PRI_IDLE Mode ................. 23 Transition for Wake from RC_RUN Mode (RC_RUN to PRI_RUN) ..................................... 25 Transition for Wake from SEC_RUN Mode (HSPLL) ............................................................. 24 Transition for Wake from Sleep (HSPLL) ................... 22 Transition to PRI_IDLE Mode .................................... 23 Transition to RC_IDLE Mode ..................................... 25 Transition to RC_RUN Mode ..................................... 27 Timing Diagrams and Specifications ................................ 257 Capture/Compare/PWM Requirements (All CCP Modules) ........................................... 263 CLKO and I/O Requirements ................................... 259 EUSART Synchronous Receive Requirements ....... 264 EUSART Synchronous Transmission Requirements ............................ 263 External Clock Requirements .................................. 257 Internal RC Accuracy ............................................... 258 PLL Clock, HS/HSPLL Mode (VDD = 4.2V to 5.5V) ........................................ 258 Reset, Watchdog Timer, Oscillator Start-up Timer, Power-up Timer and Brown-out Reset Requirements ....................... 261 Timer0 and Timer1 External Clock Requirements ................................................... 262 Top-of-Stack Access .......................................................... 42 TSTFSZ ........................................................................... 231 Two-Speed Start-up ..................................................171, 181 Two-Word Instructions ....................................................... 46 Example Cases .......................................................... 46 TXSTA Register BRGH Bit ................................................................. 135 W Watchdog Timer (WDT) ............................................171, 180 Associated Registers ............................................... 181 Control Register ....................................................... 180 During Oscillator Failure .......................................... 182 Programming Considerations .................................. 180 WWW Address ................................................................ 302 WWW, On-Line Support ...................................................... 4 X XORLW ............................................................................ 231 XORWF ........................................................................... 232PIC18F1220/1320 DS39605F-page 302 © 2007 Microchip Technology Inc. NOTES:© 2007 Microchip Technology Inc. DS39605F-page 303 PIC18F1220/1320 THE MICROCHIP WEB SITE Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: • Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s guides and hardware support documents, latest software releases and archived software • General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing • Business of Microchip – Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives CUSTOMER CHANGE NOTIFICATION SERVICE Microchip’s customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com, click on Customer Change Notification and follow the registration instructions. CUSTOMER SUPPORT Users of Microchip products can receive assistance through several channels: • Distributor or Representative • Local Sales Office • Field Application Engineer (FAE) • Technical Support • Development Systems Information Line Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://support.microchip.comPIC18F1220/1320 DS39605F-page 304 © 2007 Microchip Technology Inc. READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ Application (optional): Would you like a reply? Y N Device: Literature Number: Questions: FAX: (______) _________ - _________ PIC18F1220/1320 DS39605F 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document?© 2007 Microchip Technology Inc. DS39605F-page 305 PIC18F1220/1320 PIC18F1220/1320 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. − X /XX XXX Temperature Package Pattern Range Device Device PIC18F1220/1320(1), PIC18F1220/1320T(2); VDD range 4.2V to 5.5V PIC18LF1220/1320(1), PIC18LF1220/1320T(2); VDD range 2.5V to 5.5V Temperature Range I = -40°C to +85°C (Industrial) E = -40°C to +125°C (Extended) Package SO = SOIC SS = SSOP P = PDIP ML = QFN Pattern QTP, SQTP, Code or Special Requirements (blank otherwise) Examples: a) PIC18LF1320-I/P 301 = Industrial temp., PDIP package, Extended VDD limits, QTP pattern #301. b) PIC18LF1220-I/SO = Industrial temp., SOIC package, Extended VDD limits. Note 1: F = Standard Voltage range LF = Wide Voltage Range 2: T = in tape and reel – SOIC package onlyDS39605F-page 306 © 2007 Microchip Technology Inc. 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Pin Configurations Figure 1-1. Pinout ATtiny25/45/85 1.1 Pin Descriptions 1.1.1 VCC Supply voltage. 1.1.2 GND Ground. 1.1.3 Port B (PB5:PB0) Port B is a 6-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. 1 2 3 4 8 7 6 5 (PCINT5/RESET/ADC0/dW) PB5 (PCINT3/XTAL1/CLKI/OC1B/ADC3) PB3 (PCINT4/XTAL2/CLKO/OC1B/ADC2) PB4 GND VCC PB2 (SCK/USCK/SCL/ADC1/T0/INT0/PCINT2) PB1 (MISO/DO/AIN1/OC0B/OC1A/PCINT1) PB0 (MOSI/DI/SDA/AIN0/OC0A/OC1A/AREF/PCINT0) PDIP/SOIC/TSSOP 1 2 3 4 5 QFN/MLF 15 14 13 12 11 20 19 18 17 16 6 7 8 9 10 DNC DNC GND DNC DNC DNC DNC DNC DNC DNC NOTE: Bottom pad should be soldered to ground. DNC: Do Not Connect NOTE: TSSOP only for ATtiny45/V (PCINT5/RESET/ADC0/dW) PB5 (PCINT3/XTAL1/CLKI/OC1B/ADC3) PB3 DNC DNC (PCINT4/XTAL2/CLKO/OC1B/ADC2) PB4 VCC PB2 (SCK/USCK/SCL/ADC1/T0/INT0/PCINT2) DNC PB1 (MISO/DO/AIN1/OC0B/OC1A/PCINT1) PB0 (MOSI/DI/SDA/AIN0/OC0A/OC1A/AREF/PCINT0)ATtiny25/45/85 [DATASHEET] 3 2586QS–AVR–08/2013 Port B also serves the functions of various special features of the ATtiny25/45/85 as listed in “Alternate Functions of Port B” on page 60. On ATtiny25, the programmable I/O ports PB3 and PB4 (pins 2 and 3) are exchanged in ATtiny15 Compatibility Mode for supporting the backward compatibility with ATtiny15. 1.1.4 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running and provided the reset pin has not been disabled. The minimum pulse length is given in Table 21-4 on page 165. Shorter pulses are not guaranteed to generate a reset. The reset pin can also be used as a (weak) I/O pin.ATtiny25/45/85 [DATASHEET] 4 2586QS–AVR–08/2013 2. Overview The ATtiny25/45/85 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny25/45/85 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. 2.1 Block Diagram Figure 2-1. Block Diagram The AVR core combines a rich instruction set with 32 general purpose working registers. All 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. PROGRAM COUNTER CALIBRATED INTERNAL OSCILLATOR WATCHDOG TIMER STACK POINTER PROGRAM FLASH SRAM MCU CONTROL REGISTER GENERAL PURPOSE REGISTERS INSTRUCTION REGISTER TIMER/ COUNTER0 SERIAL UNIVERSAL INTERFACE TIMER/ COUNTER1 INSTRUCTION DECODER DATA DIR. REG.PORT B DATA REGISTER PORT B PROGRAMMING LOGIC TIMING AND CONTROL MCU STATUS REGISTER STATUS REGISTER ALU PORT B DRIVERS PB[0:5] VCC GND CONTROL LINES 8-BIT DATABUS Z ADC / ANALOG COMPARATOR INTERRUPT UNIT DATA EEPROM OSCILLATORS Y X RESETATtiny25/45/85 [DATASHEET] 5 2586QS–AVR–08/2013 The ATtiny25/45/85 provides the following features: 2/4/8K bytes of In-System Programmable Flash, 128/256/512 bytes EEPROM, 128/256/256 bytes SRAM, 6 general purpose I/O lines, 32 general purpose working registers, one 8-bit Timer/Counter with compare modes, one 8-bit high speed Timer/Counter, Universal Serial Interface, Internal and External Interrupts, a 4-channel, 10-bit ADC, a programmable Watchdog Timer with internal Oscillator, and three software selectable power saving modes. Idle mode stops the CPU while allowing the SRAM, Timer/Counter, ADC, Analog Comparator, and Interrupt system to continue functioning. Power-down mode saves the register contents, disabling all chip functions until the next Interrupt or Hardware Reset. ADC Noise Reduction mode stops the CPU and all I/O modules except ADC, to minimize switching noise during ADC conversions. The device is manufactured using Atmel’s high density non-volatile memory technology. The On-chip ISP Flash allows the Program memory to be re-programmed In-System through an SPI serial interface, by a conventional non-volatile memory programmer or by an On-chip boot code running on the AVR core. The ATtiny25/45/85 AVR is supported with a full suite of program and system development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators and Evaluation kits.ATtiny25/45/85 [DATASHEET] 6 2586QS–AVR–08/2013 3. About 3.1 Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. 3.2 Code Examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. For I/O Registers located in the extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with instructions that allow access to extended I/O. Typically, this means “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”. Note that not all AVR devices include an extended I/O map. 3.3 Capacitive Touch Sensing Atmel QTouch Library provides a simple to use solution for touch sensitive interfaces on Atmel AVR microcontrollers. The QTouch Library includes support for QTouch® and QMatrix® acquisition methods. Touch sensing is easily added to any application by linking the QTouch Library and using the Application Programming Interface (API) of the library to define the touch channels and sensors. The application then calls the API to retrieve channel information and determine the state of the touch sensor. The QTouch Library is free and can be downloaded from the Atmel website. For more information and details of implementation, refer to the QTouch Library User Guide – also available from the Atmel website. 3.4 Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C.ATtiny25/45/85 [DATASHEET] 7 2586QS–AVR–08/2013 4. Register Summary Note: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page 0x3F SREG I T H S V N Z C page 8 0x3E SPH – – – – – – SP9 SP8 page 11 0x3D SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 page 11 0x3C Reserved – 0x3B GIMSK – INT0 PCIE – – – – – page 51 0x3A GIFR – INTF0 PCIF – – – – – page 52 0x39 TIMSK – OCIE1A OCIE1B OCIE0A OCIE0B TOIE1 TOIE0 – pages 81, 102 0x38 TIFR – OCF1A OCF1B OCF0A OCF0B TOV1 TOV0 – page 81 0x37 SPMCSR – – RSIG CTPB RFLB PGWRT PGERS SPMEN page 145 0x36 Reserved – 0x35 MCUCR BODS PUD SE SM1 SM0 BODSE ISC01 ISC00 pages 37, 51, 64 0x34 MCUSR – – – – WDRF BORF EXTRF PORF page 44, 0x33 TCCR0B FOC0A FOC0B – – WGM02 CS02 CS01 CS00 page 79 0x32 TCNT0 Timer/Counter0 page 80 0x31 OSCCAL Oscillator Calibration Register page 31 0x30 TCCR1 CTC1 PWM1A COM1A1 COM1A0 CS13 CS12 CS11 CS10 pages 89, 100 0x2F TCNT1 Timer/Counter1 pages 91, 102 0x2E OCR1A Timer/Counter1 Output Compare Register A pages 91, 102 0x2D OCR1C Timer/Counter1 Output Compare Register C pages 91, 102 0x2C GTCCR TSM PWM1B COM1B1 COM1B0 FOC1B FOC1A PSR1 PSR0 pages 77, 90, 101 0x2B OCR1B Timer/Counter1 Output Compare Register B page 92 0x2A TCCR0A COM0A1 COM0A0 COM0B1 COM0B0 – WGM01 WGM00 page 77 0x29 OCR0A Timer/Counter0 – Output Compare Register A page 80 0x28 OCR0B Timer/Counter0 – Output Compare Register B page 81 0x27 PLLCSR LSM – – – – PCKE PLLE PLOCK pages 94, 103 0x26 CLKPR CLKPCE – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 page 32 0x25 DT1A DT1AH3 DT1AH2 DT1AH1 DT1AH0 DT1AL3 DT1AL2 DT1AL1 DT1AL0 page 107 0x24 DT1B DT1BH3 DT1BH2 DT1BH1 DT1BH0 DT1BL3 DT1BL2 DT1BL1 DT1BL0 page 107 0x23 DTPS1 - - - - - - DTPS11 DTPS10 page 106 0x22 DWDR DWDR[7:0] page 140 0x21 WDTCR WDIF WDIE WDP3 WDCE WDE WDP2 WDP1 WDP0 page 45 0x20 PRR – PRTIM1 PRTIM0 PRUSI PRADC page 36 0x1F EEARH EEAR8 page 20 0x1E EEARL EEAR7 EEAR6 EEAR5 EEAR4 EEAR3 EEAR2 EEAR1 EEAR0 page 21 0x1D EEDR EEPROM Data Register page 21 0x1C EECR – – EEPM1 EEPM0 EERIE EEMPE EEPE EERE page 21 0x1B Reserved – 0x1A Reserved – 0x19 Reserved – 0x18 PORTB – – PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 page 64 0x17 DDRB – – DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 page 64 0x16 PINB – – PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 page 64 0x15 PCMSK – – PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 page 52 0x14 DIDR0 – – ADC0D ADC2D ADC3D ADC1D AIN1D AIN0D pages 121, 138 0x13 GPIOR2 General Purpose I/O Register 2 page 10 0x12 GPIOR1 General Purpose I/O Register 1 page 10 0x11 GPIOR0 General Purpose I/O Register 0 page 10 0x10 USIBR USI Buffer Register page 115 0x0F USIDR USI Data Register page 115 0x0E USISR USISIF USIOIF USIPF USIDC USICNT3 USICNT2 USICNT1 USICNT0 page 115 0x0D USICR USISIE USIOIE USIWM1 USIWM0 USICS1 USICS0 USICLK USITC page 116 0x0C Reserved – 0x0B Reserved – 0x0A Reserved – 0x09 Reserved – 0x08 ACSR ACD ACBG ACO ACI ACIE – ACIS1 ACIS0 page 120 0x07 ADMUX REFS1 REFS0 ADLAR REFS2 MUX3 MUX2 MUX1 MUX0 page 134 0x06 ADCSRA ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 page 136 0x05 ADCH ADC Data Register High Byte page 137 0x04 ADCL ADC Data Register Low Byte page 137 0x03 ADCSRB BIN ACME IPR – – ADTS2 ADTS1 ADTS0 pages 120, 137 0x02 Reserved – 0x01 Reserved – 0x00 Reserved –ATtiny25/45/85 [DATASHEET] 8 2586QS–AVR–08/2013 should never be written. 2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operation the specified bit, and can therefore be used on registers containing such Status Flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only.ATtiny25/45/85 [DATASHEET] 9 2586QS–AVR–08/2013 5. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd  Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd  Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl  Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd  Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd  Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd  Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd  Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl  Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd Rd  Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd  Rd K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd  Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd  Rd  Rr Z,N,V 1 COM Rd One’s Complement Rd  0xFF  Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd  0x00  Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd  Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd  Rd  (0xFF - K) Z,N,V 1 INC Rd Increment Rd  Rd + 1 Z,N,V 1 DEC Rd Decrement Rd  Rd  1 Z,N,V 1 TST Rd Test for Zero or Minus Rd  Rd  Rd Z,N,V 1 CLR Rd Clear Register Rd  Rd  Rd Z,N,V 1 SER Rd Set Register Rd  0xFF None 1 BRANCH INSTRUCTIONS RJMP k Relative Jump PC PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC  Z None 2 RCALL k Relative Subroutine Call PC  PC + k + 1 None 3 ICALL Indirect Call to (Z) PC  Z None 3 RET Subroutine Return PC  STACK None 4 RETI Interrupt Return PC  STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd  Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd  Rr  C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd  K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC  PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC  PC + 2 or 3 None 1/2/3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC  PC + 2 or 3 None 1/2/3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC  PC + 2 or 3 None 1/2/3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PCPC+k + 1 None 1/2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PCPC+k + 1 None 1/2 BREQ k Branch if Equal if (Z = 1) then PC  PC + k + 1 None 1/2 BRNE k Branch if Not Equal if (Z = 0) then PC  PC + k + 1 None 1/2 BRCS k Branch if Carry Set if (C = 1) then PC  PC + k + 1 None 1/2 BRCC k Branch if Carry Cleared if (C = 0) then PC  PC + k + 1 None 1/2 BRSH k Branch if Same or Higher if (C = 0) then PC  PC + k + 1 None 1/2 BRLO k Branch if Lower if (C = 1) then PC  PC + k + 1 None 1/2 BRMI k Branch if Minus if (N = 1) then PC  PC + k + 1 None 1/2 BRPL k Branch if Plus if (N = 0) then PC  PC + k + 1 None 1/2 BRGE k Branch if Greater or Equal, Signed if (N  V= 0) then PC  PC + k + 1 None 1/2 BRLT k Branch if Less Than Zero, Signed if (N  V= 1) then PC  PC + k + 1 None 1/2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC  PC + k + 1 None 1/2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC  PC + k + 1 None 1/2 BRTS k Branch if T Flag Set if (T = 1) then PC  PC + k + 1 None 1/2 BRTC k Branch if T Flag Cleared if (T = 0) then PC  PC + k + 1 None 1/2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC  PC + k + 1 None 1/2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC  PC + k + 1 None 1/2 BRIE k Branch if Interrupt Enabled if ( I = 1) then PC  PC + k + 1 None 1/2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC  PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b)  1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b)  0 None 2 LSL Rd Logical Shift Left Rd(n+1)  Rd(n), Rd(0)  0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n)  Rd(n+1), Rd(7)  0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)C,Rd(n+1) Rd(n),CRd(7) Z,C,N,V 1 ROR Rd Rotate Right Through Carry Rd(7)C,Rd(n) Rd(n+1),CRd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n)  Rd(n+1), n=0..6 Z,C,N,V 1ATtiny25/45/85 [DATASHEET] 10 2586QS–AVR–08/2013 SWAP Rd Swap Nibbles Rd(3..0)Rd(7..4),Rd(7..4)Rd(3..0) None 1 BSET s Flag Set SREG(s)  1 SREG(s) 1 BCLR s Flag Clear SREG(s)  0 SREG(s) 1 BST Rr, b Bit Store from Register to T T  Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b)  T None 1 SEC Set Carry C  1 C1 CLC Clear Carry C  0 C 1 SEN Set Negative Flag N  1 N1 CLN Clear Negative Flag N  0 N 1 SEZ Set Zero Flag Z  1 Z1 CLZ Clear Zero Flag Z  0 Z 1 SEI Global Interrupt Enable I  1 I1 CLI Global Interrupt Disable I 0 I 1 SES Set Signed Test Flag S  1 S1 CLS Clear Signed Test Flag S  0 S 1 SEV Set Twos Complement Overflow. V  1 V1 CLV Clear Twos Complement Overflow V  0 V 1 SET Set T in SREG T  1 T1 CLT Clear T in SREG T  0 T 1 SEH Set Half Carry Flag in SREG H  1 H1 CLH Clear Half Carry Flag in SREG H  0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd  Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd  Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd  K None 1 LD Rd, X Load Indirect Rd  (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd  (X), X  X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X  X - 1, Rd  (X) None 2 LD Rd, Y Load Indirect Rd  (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd  (Y), Y  Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y  Y - 1, Rd  (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd  (Y + q) None 2 LD Rd, Z Load Indirect Rd  (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd  (Z), Z  Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z  Z - 1, Rd  (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd  (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd  (k) None 2 ST X, Rr Store Indirect (X) Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) Rr, X  X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X  X - 1, (X)  Rr None 2 ST Y, Rr Store Indirect (Y)  Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y)  Rr, Y  Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y  Y - 1, (Y)  Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q)  Rr None 2 ST Z, Rr Store Indirect (Z)  Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z)  Rr, Z  Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z  Z - 1, (Z)  Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q)  Rr None 2 STS k, Rr Store Direct to SRAM (k)  Rr None 2 LPM Load Program Memory R0  (Z) None 3 LPM Rd, Z Load Program Memory Rd  (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd  (Z), Z  Z+1 None 3 SPM Store Program Memory (z)  R1:R0 None IN Rd, P In Port Rd  P None 1 OUT P, Rr Out Port P  Rr None 1 PUSH Rr Push Register on Stack STACK  Rr None 2 POP Rd Pop Register from Stack Rd  STACK None 2 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/Timer) None 1 BREAK Break For On-chip Debug Only None N/A Mnemonics Operands Description Operation Flags #ClocksATtiny25/45/85 [DATASHEET] 11 2586QS–AVR–08/2013 6. Ordering Information Notes: 1. For speed vs. supply voltage, see section 21.3 “Speed” on page 163. 2. All Pb-free, halide-free, fully green, and comply with European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: H = NiPdAu lead finish, U/N = matte tin, R = tape & reel. 4. Can also be supplied in wafer form. Contact your local Atmel sales office for ordering information and minimum quantities. 5. For characteristics, see “Appendix A – Specification at 105C”. 6. For characteristics, see “Appendix B – Specification at 125C”. 6.1 ATtiny25 Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 10 1.8 – 5.5 Industrial (-40C to +85C) (4) 8P3 ATtiny25V-10PU 8S2 ATtiny25V-10SU ATtiny25V-10SUR ATtiny25V-10SH ATtiny25V-10SHR S8S1 ATtiny25V-10SSU ATtiny25V-10SSUR ATtiny25V-10SSH ATtiny25V-10SSHR 20M1 ATtiny25V-10MU ATtiny25V-10MUR Industrial (-40C to +105C) (5) 8S2 ATtiny25V-10SN ATtiny25V-10SNR S8S1 ATtiny25V-10SSN ATtiny25V-10SSNR Industrial (-40C to +125C) (6) 20M1 ATtiny25V-10MF ATtiny25V-10MFR 20 2.7 – 5.5 Industrial (-40C to +85C) (4) 8P3 ATtiny25-20PU 8S2 ATtiny25-20SU ATtiny25-20SUR ATtiny25-20SH ATtiny25-20SHR S8S1 ATtiny25-20SSU ATtiny25-20SSUR ATtiny25-20SSH ATtiny25-20SSHR 20M1 ATtiny25-20MU ATtiny25-20MUR Industrial (-40C to +105C) (5) 8S2 ATtiny25-20SN ATtiny25-20SNR S8S1 ATtiny25-20SSN ATtiny25-20SSNR Industrial (-40C to +125C) (6) 20M1 ATtiny25-20MF ATtiny25-20MFR Package Types 8P3 8-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 8S2 8-lead, 0.208" Wide, Plastic Gull-Wing Small Outline (EIAJ SOIC) S8S1 8-lead, 0.150" Wide, Plastic Gull-Wing Small Outline (JEDEC SOIC) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)ATtiny25/45/85 [DATASHEET] 12 2586QS–AVR–08/2013 Notes: 1. For speed vs. supply voltage, see section 21.3 “Speed” on page 163. 2. All packages are Pb-free, halide-free and fully green and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: – H: NiPdAu lead finish – U: matte tin – R: tape & reel 4. These devices can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 6.2 ATtiny45 Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 10 1.8 – 5.5 Industrial (-40C to +85C) (4) 8P3 ATtiny45V-10PU 8S2 ATtiny45V-10SU ATtiny45V-10SUR ATtiny45V-10SH ATtiny45V-10SHR 8X ATtiny45V-10XU ATtiny45V-10XUR 20M1 ATtiny45V-10MU ATtiny45V-10MUR 20 2.7 – 5.5 Industrial (-40C to +85C) (4) 8P3 ATtiny45-20PU 8S2 ATtiny45-20SU ATtiny45-20SUR ATtiny45-20SH ATtiny45-20SHR 8X ATtiny45-20XU ATtiny45-20XUR 20M1 ATtiny45-20MU ATtiny45-20MUR Package Types 8P3 8-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 8S2 8-lead, 0.208" Wide, Plastic Gull-Wing Small Outline (EIAJ SOIC) 8X 8-lead, 4.4 mm Wide, Plastic Thin Shrink Small Outline Package (TSSOP) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)ATtiny25/45/85 [DATASHEET] 13 2586QS–AVR–08/2013 Notes: 1. For speed vs. supply voltage, see section 21.3 “Speed” on page 163. 2. All packages are Pb-free, halide-free and fully green and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: – H: NiPdAu lead finish – U: matte tin – R: tape & reel 4. These devices can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 6.3 ATtiny85 Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 10 1.8 – 5.5 Industrial (-40C to +85C) (4) 8P3 ATtiny85V-10PU 8S2 ATtiny85V-10SU ATtiny85V-10SUR ATtiny85V-10SH ATtiny85V-10SHR 20M1 ATtiny85V-10MU ATtiny85V-10MUR 20 2.7 – 5.5 Industrial (-40C to +85C) (4) 8P3 ATtiny85-20PU 8S2 ATtiny85-20SU ATtiny85-20SUR ATtiny85-20SH ATtiny85-20SHR 20M1 ATtiny85-20MU ATtiny85-20MUR Package Types 8P3 8-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 8S2 8-lead, 0.208" Wide, Plastic Gull-Wing Small Outline (EIAJ SOIC) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)ATtiny25/45/85 [DATASHEET] 14 2586QS–AVR–08/2013 7. Packaging Information 7.1 8P3 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 8P3, 8-lead, 0.300" Wide Body, Plastic Dual In-line Package (PDIP) 01/09/02 8P3 B D D1 E E1 e b2 L b A2 A 1 N eA c b3 4 PLCS Top View Side View End View COMMON DIMENSIONS (Unit of Measure = inches) SYMBOL MIN NOM MAX NOTE Notes: 1. This drawing is for general information only; refer to JEDEC Drawing MS-001, Variation BA for additional information. 2. Dimensions A and L are measured with the package seated in JEDEC seating plane Gauge GS-3. 3. D, D1 and E1 dimensions do not include mold Flash or protrusions. Mold Flash or protrusions shall not exceed 0.010 inch. 4. E and eA measured with the leads constrained to be perpendicular to datum. 5. Pointed or rounded lead tips are preferred to ease insertion. 6. b2 and b3 maximum dimensions do not include Dambar protrusions. Dambar protrusions shall not exceed 0.010 (0.25 mm). A 0.210 2 A2 0.115 0.130 0.195 b 0.014 0.018 0.022 5 b2 0.045 0.060 0.070 6 b3 0.030 0.039 0.045 6 c 0.008 0.010 0.014 D 0.355 0.365 0.400 3 D1 0.005 3 E 0.300 0.310 0.325 4 E1 0.240 0.250 0.280 3 e 0.100 BSC eA 0.300 BSC 4 L 0.115 0.130 0.150 2ATtiny25/45/85 [DATASHEET] 15 2586QS–AVR–08/2013 7.2 8S2 TITLE GPC DRAWING NO. REV. Package Drawing Contact: packagedrawings@atmel.com STN F 8S2 8S2, 8-lead, 0.208” Body, Plastic Small Outline Package (EIAJ) 4/15/08 COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE Notes: 1. This drawing is for general information only; refer to EIAJ Drawing EDR-7320 for additional information. 2. Mismatch of the upper and lower dies and resin burrs aren't included. 3. Determines the true geometric position. 4. Values b,C apply to plated terminal. The standard thickness of the plating layer shall measure between 0.007 to .021 mm. A 1.70 2.16 A1 0.05 0.25 b 0.35 0.48 4 C 0.15 0.35 4 D 5.13 5.35 E1 5.18 5.40 2 E 7.70 8.26 L 0.51 0.85 θ 0° 8° e 1.27 BSC 3 θ 1 N E TOP VIEW TOP VIEW C E1 END VIEW END VIEW A b L A1 e D SIDE VIEW SIDE VIEWATtiny25/45/85 [DATASHEET] 16 2586QS–AVR–08/2013 7.3 S8S1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. S8S1, 8-lead, 0.150" Wide Body, Plastic Gull Wing Small Outline (JEDEC SOIC) 7/28/03 S8S1 A COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE Notes: 1. This drawing is for general information only; refer to JEDEC Drawing MS-012 for proper dimensions, tolerances, datums,etc. E 5.79 6.20 E1 3.81 3.99 A 1.35 1.75 A1 0.1 0.25 D 4.80 4.98 C 0.17 0.25 b 0.31 0.51 L 0.4 1.27 e 1.27 BSC 0o 8o Top View Side View End View 1 N C A A1 b L e D E1 EATtiny25/45/85 [DATASHEET] 17 2586QS–AVR–08/2013 7.4 8X TITLE DRAWING NO. R REV. Note: These drawings are for general information only. Refer to JEDEC Drawing MO-153AC. 2325 Orchard Parkway San Jose, CA 95131 4/14/05 8X, 8-lead, 4.4 mm Body Width, Plastic Thin Shrink Small Outline Package (TSSOP) 8X A COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A 1.05 1.10 1.20 A1 0.05 0.10 0.15 b 0.25 – 0.30 C – 0.127 – D 2.90 3.05 3.10 E1 4.30 4.40 4.50 E 6.20 6.40 6.60 e 0.65 TYP L 0.50 0.60 0.70 Ø 0o – 8o C A b L A1 D Side View Top View End View E 1 E1 e ØATtiny25/45/85 [DATASHEET] 18 2586QS–AVR–08/2013 7.5 20M1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 20M1, 20-pad, 4 x 4 x 0.8 mm Body, Lead Pitch 0.50 mm, 20M1 B 10/27/04 2.6 mm Exposed Pad, Micro Lead Frame Package (MLF) A 0.70 0.75 0.80 A1 – 0.01 0.05 A2 0.20 REF b 0.18 0.23 0.30 D 4.00 BSC D2 2.45 2.60 2.75 E 4.00 BSC E2 2.45 2.60 2.75 e 0.50 BSC L 0.35 0.40 0.55 SIDE VIEW Pin 1 ID Pin #1 Notch (0.20 R) BOTTOM VIEW TOP VIEW Note: Reference JEDEC Standard MO-220, Fig. 1 (SAW Singulation) WGGD-5. COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE D E e A2 A1 A D2 E2 0.08 C L 1 2 3 b 1 2 3ATtiny25/45/85 [DATASHEET] 19 2586QS–AVR–08/2013 8. Errata 8.1 Errata ATtiny25 The revision letter in this section refers to the revision of the ATtiny25 device. 8.1.1 Rev D – F No known errata. 8.1.2 Rev B – C • EEPROM read may fail at low supply voltage / low clock frequency 1. EEPROM read may fail at low supply voltage / low clock frequency Trying to read EEPROM at low clock frequencies and/or low supply voltage may result in invalid data. Problem Fix/Workaround Do not use the EEPROM when clock frequency is below 1MHz and supply voltage is below 2V. If operating frequency can not be raised above 1MHz then supply voltage should be more than 2V. Similarly, if supply voltage can not be raised above 2V then operating frequency should be more than 1MHz. This feature is known to be temperature dependent but it has not been characterised. Guidelines are given for room temperature, only. 8.1.3 Rev A Not sampled. 8.2 Errata ATtiny45 The revision letter in this section refers to the revision of the ATtiny45 device. 8.2.1 Rev F – G No known errata 8.2.2 Rev D – E • EEPROM read may fail at low supply voltage / low clock frequency 1. EEPROM read may fail at low supply voltage / low clock frequency Trying to read EEPROM at low clock frequencies and/or low supply voltage may result in invalid data. Problem Fix/Workaround Do not use the EEPROM when clock frequency is below 1MHz and supply voltage is below 2V. If operating frequency can not be raised above 1MHz then supply voltage should be more than 2V. Similarly, if supply voltage can not be raised above 2V then operating frequency should be more than 1MHz. This feature is known to be temperature dependent but it has not been characterised. Guidelines are given for room temperature, only.ATtiny25/45/85 [DATASHEET] 20 2586QS–AVR–08/2013 8.2.3 Rev B – C • PLL not locking • EEPROM read from application code does not work in Lock Bit Mode 3 • EEPROM read may fail at low supply voltage / low clock frequency • Timer Counter 1 PWM output generation on OC1B- XOC1B does not work correctly 1. PLL not locking When at frequencies below 6.0 MHz, the PLL will not lock Problem fix / Workaround When using the PLL, run at 6.0 MHz or higher. 2. EEPROM read from application code does not work in Lock Bit Mode 3 When the Memory Lock Bits LB2 and LB1 are programmed to mode 3, EEPROM read does not work from the application code. Problem Fix/Work around Do not set Lock Bit Protection Mode 3 when the application code needs to read from EEPROM. 3. EEPROM read may fail at low supply voltage / low clock frequency Trying to read EEPROM at low clock frequencies and/or low supply voltage may result in invalid data. Problem Fix/Workaround Do not use the EEPROM when clock frequency is below 1MHz and supply voltage is below 2V. If operating frequency can not be raised above 1MHz then supply voltage should be more than 2V. Similarly, if supply voltage can not be raised above 2V then operating frequency should be more than 1MHz. This feature is known to be temperature dependent but it has not been characterised. Guidelines are given for room temperature, only. 4. Timer Counter 1 PWM output generation on OC1B – XOC1B does not work correctly Timer Counter1 PWM output OC1B-XOC1B does not work correctly. Only in the case when the control bits, COM1B1 and COM1B0 are in the same mode as COM1A1 and COM1A0, respectively, the OC1B-XOC1B output works correctly. Problem Fix/Work around The only workaround is to use same control setting on COM1A[1:0] and COM1B[1:0] control bits, see table 14- 4 in the data sheet. The problem has been fixed for Tiny45 rev D. 8.2.4 Rev A • Too high power down power consumption • DebugWIRE looses communication when single stepping into interrupts • PLL not locking • EEPROM read from application code does not work in Lock Bit Mode 3 • EEPROM read may fail at low supply voltage / low clock frequency 1. Too high power down power consumption Three situations will lead to a too high power down power consumption. These are: – An external clock is selected by fuses, but the I/O PORT is still enabled as an output. – The EEPROM is read before entering power down. – VCC is 4.5 volts or higher. Problem fix / WorkaroundATtiny25/45/85 [DATASHEET] 21 2586QS–AVR–08/2013 – When using external clock, avoid setting the clock pin as Output. – Do not read the EEPROM if power down power consumption is important. – Use VCC lower than 4.5 Volts. 2. DebugWIRE looses communication when single stepping into interrupts When receiving an interrupt during single stepping, debugwire will loose communication. Problem fix / Workaround – When singlestepping, disable interrupts. – When debugging interrupts, use breakpoints within the interrupt routine, and run into the interrupt. 3. PLL not locking When at frequencies below 6.0 MHz, the PLL will not lock Problem fix / Workaround When using the PLL, run at 6.0 MHz or higher. 4. EEPROM read from application code does not work in Lock Bit Mode 3 When the Memory Lock Bits LB2 and LB1 are programmed to mode 3, EEPROM read does not work from the application code. Problem Fix/Work around Do not set Lock Bit Protection Mode 3 when the application code needs to read from EEPROM. 5. EEPROM read may fail at low supply voltage / low clock frequency Trying to read EEPROM at low clock frequencies and/or low supply voltage may result in invalid data. Problem Fix/Workaround Do not use the EEPROM when clock frequency is below 1MHz and supply voltage is below 2V. If operating frequency can not be raised above 1MHz then supply voltage should be more than 2V. Similarly, if supply voltage can not be raised above 2V then operating frequency should be more than 1MHz. This feature is known to be temperature dependent but it has not been characterized. Guidelines are given for room temperature, only.ATtiny25/45/85 [DATASHEET] 22 2586QS–AVR–08/2013 8.3 Errata ATtiny85 The revision letter in this section refers to the revision of the ATtiny85 device. 8.3.1 Rev B – C No known errata. 8.3.2 Rev A • EEPROM read may fail at low supply voltage / low clock frequency 1. EEPROM read may fail at low supply voltage / low clock frequency Trying to read EEPROM at low clock frequencies and/or low supply voltage may result in invalid data. Problem Fix/Workaround Do not use the EEPROM when clock frequency is below 1MHz and supply voltage is below 2V. If operating frequency can not be raised above 1MHz then supply voltage should be more than 2V. Similarly, if supply voltage can not be raised above 2V then operating frequency should be more than 1MHz. This feature is known to be temperature dependent but it has not been characterised. Guidelines are given for room temperature, only.ATtiny25/45/85 [DATASHEET] 23 2586QS–AVR–08/2013 9. Datasheet Revision History 9.1 Rev. 2586Q-08/13 9.2 Rev. 2586P-06/13 9.3 Rev. 2586O-02/13 Updated ordering codes on page 11, page 12, and page 13. 9.4 Rev. 2586N-04/11 1. Added: – Section “Capacitive Touch Sensing” on page 6. 2. Updated: – Document template. – Removed “Preliminary” on front page. All devices now final and in production. – Section “Limitations” on page 36. – Program example on page 49. – Section “Overview” on page 122. – Table 17-4 on page 135. – Section “Limitations of debugWIRE” on page 140. – Section “Serial Programming Algorithm” on page 151. – Table 21-7 on page 166. – EEPROM errata on pages 19, 19, 20, 21, and 22 – Ordering information on pages 11, 12, and 13. 9.5 Rev. 2586M-07/10 1. Clarified Section 6.4 “Clock Output Buffer” on page 31. 2. Added Ordering Codes -SN and -SNR for ATtiny25 extended temperature. 9.6 Rev. 2586L-06/10 1. Added: – TSSOP for ATtiny45 in “Features” on page 1, Pinout Figure 1-1 on page 2, Ordering Information in Section 6.2 “ATtiny45” on page 12, and Packaging Information in Section 7.4 “8X” on page 17 – Table 6-11, “Capacitance of Low-Frequency Crystal Oscillator,” on page 29 – Figure 22-36 on page 191 and Figure 22-37 on page 191, Typical Characteristics plots for Bandgap Voltage vs. VCC and Temperature – Extended temperature in Section 6.1 “ATtiny25” on page 11, Ordering Information 1. “Bit 3 – FOC1B: Force Output Compare Match 1B” description in “GTCCR – General Timer/Counter1 Control Register” on page 90 updated: PB3 in “compare match output pin PB3 (OC1B)” corrected to PB4. 1. Updated description of “EEARH – EEPROM Address Register” and “EEARL – EEPROM Address Register” on page 20.ATtiny25/45/85 [DATASHEET] 24 2586QS–AVR–08/2013 – Tape & reel part numbers in Ordering Information, in Section 6.1 “ATtiny25” on page 11 and Section 6.2 “ATtiny45” on page 12 2. Updated: – “Features” on page 1, removed Preliminary from ATtiny25 – Section 8.4.2 “Code Example” on page 44 – “PCMSK – Pin Change Mask Register” on page 52, Bit Descriptions – “TCCR1 – Timer/Counter1 Control Register” on page 89 and “GTCCR – General Timer/Counter1 Control Register” on page 90, COM bit descriptions clarified – Section 20.3.2 “Calibration Bytes” on page 150, frequencies (8 MHz, 6.4 MHz) – Table 20-11, “Minimum Wait Delay Before Writing the Next Flash or EEPROM Location,” on page 153, value for tWD_ERASE – Table 20-16, “High-voltage Serial Programming Instruction Set for ATtiny25/45/85,” on page 158 – Table 21-1, “DC Characteristics. TA = -40C to +85C,” on page 161, notes adjusted – Table 21-11, “Serial Programming Characteristics, TA = -40C to +85C, VCC = 1.8 - 5.5V (Unless Otherwise Noted),” on page 170, added tSLIV – Bit syntax throughout the datasheet, e.g. from CS02:0 to CS0[2:0]. 9.7 Rev. 2586K-01/08 1. Updated Document Template. 2. Added Sections: – “Data Retention” on page 6 – “Low Level Interrupt” on page 49 – “Device Signature Imprint Table” on page 149 3. Updated Sections: – “Internal PLL for Fast Peripheral Clock Generation - clkPCK” on page 24 – “System Clock and Clock Options” on page 23 – “Internal PLL in ATtiny15 Compatibility Mode” on page 24 – “Sleep Modes” on page 34 – “Software BOD Disable” on page 35 – “External Interrupts” on page 49 – “Timer/Counter1 in PWM Mode” on page 97 – “USI – Universal Serial Interface” on page 108 – “Temperature Measurement” on page 133 – “Reading Lock, Fuse and Signature Data from Software” on page 143 – “Program And Data Memory Lock Bits” on page 147 – “Fuse Bytes” on page 148 – “Signature Bytes” on page 150 – “Calibration Bytes” on page 150 – “System and Reset Characteristics” on page 165 4. Added Figures: – “Reset Pin Output Voltage vs. Sink Current (VCC = 3V)” on page 184 – “Reset Pin Output Voltage vs. Sink Current (VCC = 5V)” on page 185 – “Reset Pin Output Voltage vs. Source Current (VCC = 3V)” on page 185ATtiny25/45/85 [DATASHEET] 25 2586QS–AVR–08/2013 – “Reset Pin Output Voltage vs. Source Current (VCC = 5V)” on page 186 5. Updated Figure: – “Reset Logic” on page 39 6. Updated Tables: – “Start-up Times for Internal Calibrated RC Oscillator Clock” on page 28 – “Start-up Times for Internal Calibrated RC Oscillator Clock (in ATtiny15 Mode)” on page 28 – “Start-up Times for the 128 kHz Internal Oscillator” on page 28 – “Compare Mode Select in PWM Mode” on page 86 – “Compare Mode Select in PWM Mode” on page 98 – “DC Characteristics. TA = -40C to +85C” on page 161 – “Calibration Accuracy of Internal RC Oscillator” on page 164 – “ADC Characteristics” on page 167 7. Updated Code Example in Section: – “Write” on page 17 8. Updated Bit Descriptions in: – “MCUCR – MCU Control Register” on page 37 – “Bits 7:6 – COM0A[1:0]: Compare Match Output A Mode” on page 77 – “Bits 5:4 – COM0B[1:0]: Compare Match Output B Mode” on page 77 – “Bits 2:0 – ADTS[2:0]: ADC Auto Trigger Source” on page 138 – “SPMCSR – Store Program Memory Control and Status Register” on page 145. 9. Updated description of feature “EEPROM read may fail at low supply voltage / low clock frequency” in Sections: – “Errata ATtiny25” on page 19 – “Errata ATtiny45” on page 19 – “Errata ATtiny85” on page 22 10. Updated Package Description in Sections: – “ATtiny25” on page 11 – “ATtiny45” on page 12 – “ATtiny85” on page 13 11. Updated Package Drawing: – “S8S1” on page 16 12. Updated Order Codes for: – “ATtiny25” on page 11 9.8 Rev. 2586J-12/06 1. Updated “Low Power Consumption” on page 1. 2. Updated description of instruction length in “Architectural Overview” . 3. Updated Flash size in “In-System Re-programmable Flash Program Memory” on page 15. 4. Updated cross-references in sections “Atomic Byte Programming” , “Erase” and “Write” , starting on page 17. 5. Updated “Atomic Byte Programming” on page 17.ATtiny25/45/85 [DATASHEET] 26 2586QS–AVR–08/2013 6. Updated “Internal PLL for Fast Peripheral Clock Generation - clkPCK” on page 24. 7. Replaced single clocking system figure with two: Figure 6-2 and Figure 6-3. 8. Updated Table 6-1 on page 25, Table 6-13 on page 30 and Table 6-6 on page 27. 9. Updated “Calibrated Internal Oscillator” on page 27. 10. Updated Table 6-5 on page 26. 11. Updated “OSCCAL – Oscillator Calibration Register” on page 31. 12. Updated “CLKPR – Clock Prescale Register” on page 32. 13. Updated “Power-down Mode” on page 35. 14. Updated “Bit 0” in “PRR – Power Reduction Register” on page 38. 15. Added footnote to Table 8-3 on page 46. 16. Updated Table 10-5 on page 63. 17. Deleted “Bits 7, 2” in “MCUCR – MCU Control Register” on page 64. 18. Updated and moved section “Timer/Counter0 Prescaler and Clock Sources”, now located on page 66. 19. Updated “Timer/Counter1 Initialization for Asynchronous Mode” on page 86. 20. Updated bit description in “PLLCSR – PLL Control and Status Register” on page 94 and “PLLCSR – PLL Control and Status Register” on page 103. 21. Added recommended maximum frequency in“Prescaling and Conversion Timing” on page 125. 22. Updated Figure 17-8 on page 129 . 23. Updated “Temperature Measurement” on page 133. 24. Updated Table 17-3 on page 134. 25. Updated bit R/W descriptions in: “TIMSK – Timer/Counter Interrupt Mask Register” on page 81, “TIFR – Timer/Counter Interrupt Flag Register” on page 81, “TIMSK – Timer/Counter Interrupt Mask Register” on page 92, “TIFR – Timer/Counter Interrupt Flag Register” on page 93, “PLLCSR – PLL Control and Status Register” on page 94, “TIMSK – Timer/Counter Interrupt Mask Register” on page 102, “TIFR – Timer/Counter Interrupt Flag Register” on page 103, “PLLCSR – PLL Control and Status Register” on page 103 and “DIDR0 – Digital Input Disable Register 0” on page 138. 26. Added limitation to “Limitations of debugWIRE” on page 140. 27. Updated “DC Characteristics” on page 161. 28. Updated Table 21-7 on page 166. 29. Updated Figure 21-6 on page 171. 30. Updated Table 21-12 on page 171. 31. Updated Table 22-1 on page 177. 32. Updated Table 22-2 on page 177. 33. Updated Table 22-30, Table 22-31 and Table 22-32, starting on page 188. 34. Updated Table 22-33, Table 22-34 and Table 22-35, starting on page 189. 35. Updated Table 22-39 on page 192. 36. Updated Table 22-46, Table 22-47, Table 22-48 and Table 22-49.ATtiny25/45/85 [DATASHEET] 27 2586QS–AVR–08/2013 9.9 Rev. 2586I-09/06 9.10 Rev. 2586H-06/06 9.11 Rev. 2586G-05/06 9.12 Rev. 2586F-04/06 1. All Characterization data moved to “Electrical Characteristics” on page 161. 2. All Register Descriptions are gathered up in seperate sections in the end of each chapter. 3. Updated Table 11-3 on page 78, Table 11-5 on page 79, Table 11-6 on page 80 and Table 20-4 on page 148. 4. Updated “Calibrated Internal Oscillator” on page 27. 5. Updated Note in Table 7-1 on page 34. 6. Updated “System Control and Reset” on page 39. 7. Updated Register Description in “I/O Ports” on page 53. 8. Updated Features in “USI – Universal Serial Interface” on page 108. 9. Updated Code Example in “SPI Master Operation Example” on page 110 and “SPI Slave Operation Example” on page 111. 10. Updated “Analog Comparator Multiplexed Input” on page 119. 11. Updated Figure 17-1 on page 123. 12. Updated “Signature Bytes” on page 150. 13. Updated “Electrical Characteristics” on page 161. 1. Updated “Calibrated Internal Oscillator” on page 27. 2. Updated Table 6.5.1 on page 31. 3. Added Table 21-2 on page 164. 1. Updated “Internal PLL for Fast Peripheral Clock Generation - clkPCK” on page 24. 2. Updated “Default Clock Source” on page 30. 3. Updated “Low-Frequency Crystal Oscillator” on page 29. 4. Updated “Calibrated Internal Oscillator” on page 27. 5. Updated “Clock Output Buffer” on page 31. 6. Updated “Power Management and Sleep Modes” on page 34. 7. Added “Software BOD Disable” on page 35. 8. Updated Figure 16-1 on page 119. 9. Updated “Bit 6 – ACBG: Analog Comparator Bandgap Select” on page 120. 10. Added note for Table 17-2 on page 125. 11. Updated “Register Summary” on page 7. 1. Updated “Digital Input Enable and Sleep Modes” on page 57. 2. Updated Table 20-16 on page 158. 3. Updated “Ordering Information” on page 11.ATtiny25/45/85 [DATASHEET] 28 2586QS–AVR–08/2013 9.13 Rev. 2586E-03/06 9.14 Rev. 2586D-02/06 9.15 Rev. 2586C-06/05 9.16 Rev. 2586B-05/05 9.17 Rev. 2586A-02/05 Initial revision. 1. Updated Features in “Analog to Digital Converter” on page 122. 2. Updated Operation in “Analog to Digital Converter” on page 122. 3. Updated Table 17-2 on page 133. 4. Updated Table 17-3 on page 134. 5. Updated “Errata” on page 19. 1. Updated Table 6-13 on page 30, Table 6-10 on page 29, Table 6-3 on page 26, Table 6-9 on page 28, Table 6-5 on page 26, Table 9-1 on page 48,Table 17-4 on page 135, Table 20-16 on page 158, Table 21-8 on page 167. 2. Updated “Timer/Counter1 in PWM Mode” on page 86. 3. Updated text “Bit 2 – TOV1: Timer/Counter1 Overflow Flag” on page 93. 4. Updated values in “DC Characteristics” on page 161. 5. Updated “Register Summary” on page 7. 6. Updated “Ordering Information” on page 11. 7. Updated Rev B and C in “Errata ATtiny45” on page 19. 8. All references to power-save mode are removed. 9. Updated Register Adresses. 1. Updated “Features” on page 1. 2. Updated Figure 1-1 on page 2. 3. Updated Code Examples on page 18 and page 19. 4. Moved “Temperature Measurement” to Section 17.12 page 133. 5. Updated “Register Summary” on page 7. 6. Updated “Ordering Information” on page 11. 1. CLKI added, instances of EEMWE/EEWE renamed EEMPE/EEPE, removed some TBD. Removed “Preliminary Description” from “Temperature Measurement” on page 133. 2. Updated “Features” on page 1. 3. Updated Figure 1-1 on page 2 and Figure 8-1 on page 39. 4. Updated Table 7-2 on page 38, Table 10-4 on page 63, Table 10-5 on page 63 5. Updated “Serial Programming Instruction set” on page 153. 6. Updated SPH register in “Instruction Set Summary” on page 9. 7. Updated “DC Characteristics” on page 161. 8. Updated “Ordering Information” on page 11. 9. Updated “Errata” on page 19.ATtiny25/45/85 [DATASHEET] 29 2586QS–AVR–08/2013Atmel Corporation 1600 Technology Drive San Jose, CA 95110 USA Tel: (+1) (408) 441-0311 Fax: (+1) (408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Roa Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan G.K. 16F Shin-Osaki Kangyo Bldg 1-6-4 Osaki, Shinagawa-ku Tokyo 141-0032 JAPAN Tel: (+81) (3) 6417-0300 Fax: (+81) (3) 6417-0370 © 2013 Atmel Corporation. All rights reserved. / Rev.: 2586QS–AVR–08/2013 Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. 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SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2008, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. 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The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.© 2008 Microchip Technology Inc. DS39631E-page 1 PIC18F2420/2520/4420/4520 Power Management Features: • Run: CPU on, Peripherals on • Idle: CPU off, Peripherals on • Sleep: CPU off, Peripherals off • Ultra Low 50nA Input Leakage • Run mode Currents Down to 11 μA Typical • Idle mode Currents Down to 2.5 μA Typical • Sleep mode Current Down to 100 nA Typical • Timer1 Oscillator: 900 nA, 32 kHz, 2V • Watchdog Timer: 1.4 μA, 2V Typical • Two-Speed Oscillator Start-up Flexible Oscillator Structure: • Four Crystal modes, up to 40 MHz • 4x Phase Lock Loop (PLL) – Available for Crystal and Internal Oscillators • Two External RC modes, up to 4 MHz • Two External Clock modes, up to 40 MHz • Internal Oscillator Block: - Fast wake from Sleep and Idle, 1 μs typical - 8 use-selectable frequencies, from 31 kHz to 8 MHz - Provides a complete range of clock speeds from 31 kHz to 32 MHz when used with PLL - User-tunable to compensate for frequency drift • Secondary Oscillator using Timer1 @ 32 kHz • Fail-Safe Clock Monitor: - Allows for safe shutdown if peripheral clock stops Peripheral Highlights: • High-Current Sink/Source 25 mA/25 mA • Three Programmable External Interrupts • Four Input Change Interrupts • Up to 2 Capture/Compare/PWM (CCP) modules, one with Auto-Shutdown (28-pin devices) • Enhanced Capture/Compare/PWM (ECCP) module (40/44-pin devices only): - One, two or four PWM outputs - Selectable polarity - Programmable dead time - Auto-shutdown and auto-restart Peripheral Highlights (Continued): • Master Synchronous Serial Port (MSSP) module Supporting 3-Wire SPI (all 4 modes) and I2C™ Master and Slave modes • Enhanced Addressable USART module: - Supports RS-485, RS-232 and LIN/J2602 - RS-232 operation using internal oscillator block (no external crystal required) - Auto-wake-up on Start bit - Auto-Baud Detect • 10-Bit, up to 13-Channel Analog-to-Digital (A/D) Converter module: - Auto-acquisition capability - Conversion available during Sleep • Dual Analog Comparators with Input Multiplexing • Programmable 16-Level High/Low-Voltage Detection (HLVD) module: - Supports interrupt on High/Low-Voltage Detection Special Microcontroller Features: • C Compiler Optimized Architecture: - Optional extended instruction set designed to optimize re-entrant code • 100,000 Erase/Write Cycle Enhanced Flash Program Memory Typical • 1,000,000 Erase/Write Cycle Data EEPROM Memory Typical • Flash/Data EEPROM Retention: 100 Years Typical • Self-Programmable under Software Control • Priority Levels for Interrupts • 8 x 8 Single-Cycle Hardware Multiplier • Extended Watchdog Timer (WDT): - Programmable period from 4 ms to 131s • Single-Supply 5V In-Circuit Serial Programming™ (ICSP™) via Two Pins • In-Circuit Debug (ICD) via Two Pins • Wide Operating Voltage Range: 2.0V to 5.5V • Programmable Brown-out Reset (BOR) with Software Enable Option - Device Program Memory Data Memory I/O 10-Bit A/D (ch) CCP/ ECCP (PWM) MSSP EUSART Comp. Timers 8/16-Bit Flash (bytes) # Single-Word Instructions SRAM (bytes) EEPROM (bytes) SPI Master I 2C™ PIC18F2420 16K 8192 768 256 25 10 2/0 Y Y 1 2 1/3 PIC18F2520 32K 16384 1536 256 25 10 2/0 Y Y 1 2 1/3 PIC18F4420 16K 8192 768 256 36 13 1/1 Y Y 1 2 1/3 PIC18F4520 32K 16384 1536 256 36 13 1/1 Y Y 1 2 1/3 28/40/44-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt TechnologyPIC18F2420/2520/4420/4520 DS39631E-page 2 © 2008 Microchip Technology Inc. Pin Diagrams PIC18F2520 10 11 2 3 4 5 6 1 8 7 9 12 13 14 15 16 17 18 19 20 23 24 25 26 27 28 22 21 MCLR/VPP/RE3 RA0/AN0 RA1/AN1 RA2/AN2/VREF-/CVREF RA3/AN3/VREF+ RA4/T0CKI/C1OUT RA5/AN4/SS/HLVDIN/C2OUT VSS OSC1/CLKI/RA7 OSC2/CLKO/RA6 RC0/T1OSO/T13CKI RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL RB7/KBI3/PGD RB6//KBI2/PGC RB5/KBI1/PGM RB4/KBI0/AN11 RB3/AN9/CCP2(1) RB2/INT2/AN8 RB1/INT1/AN10 RB0/INT0/FLT0/AN12 VDD VSS RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA 28-Pin SPDIP, SOIC PIC18F2420 Note 1: RB3 is the alternate pin for CCP2 multiplexing. 10 11 2 3 6 1 18 19 20 21 22 12 13 14 15 8 7 16 17 2827 2625 2423 9 PIC18F2420 RC0/T1OSO/T13CKI 5 4 RB7/KBI3/PGD RB6/KBI2/PGC RB5/KBI1/PGM RB4KBI0/AN11 RB3/AN9/CCP2(1) RB2/INT2/AN8 RB1/INT1/AN10 RB0/INT0/FLT0/AN12 VDD VSS RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA MCLR/VPP/RE3 RA1/AN1 RA0/AN0 RA2/AN2/VREF-/CVREF RA3/AN3/VREF+ RA4/T0CKI/C1OUT RA5/AN4/SS/HLVDIN/C2OUT VSS OSC1/CLKI/RA7 OSC2/CLKO/RA6 RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL PIC18F2520 28-Pin QFN RB7/KBI3/PGD RB6/KBI2/PGC RB5/KBI1/PGM RB4/KBI0/AN11 RB3/AN9/CCP2(1) RB2/INT2/AN8 RB1/INT1/AN10 RB0/INT0/FLT0/AN12 VDD VSS RD7/PSP7/P1D RD6/PSP6/P1C RD5/PSP5/P1B RD4/PSP4 RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 MCLR/VPP/RE3 RA0/AN0 RA1/AN1 RA2/AN2/VREF-/CVREF RA3/AN3/VREF+ RA4/T0CKI/C1OUT RA5/AN4/SS/HLVDIN/C2OUT RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VDD VSS OSC1/CLKI/RA7 OSC2/CLKO/RA6 RC0/T1OSO/T13CKI RC1/T1OSI/CCP2(1) RC2/CCP1/P1A RC3/SCK/SCL RD0/PSP0 RD1/PSP1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 PIC18F4520 40-Pin PDIP PIC18F4420© 2008 Microchip Technology Inc. DS39631E-page 3 PIC18F2420/2520/4420/4520 Pin Diagrams (Cont.’d) Note 1: RB3 is the alternate pin for CCP2 multiplexing. 10 11 2 3 4 5 6 1 12 13 14 15 18 19 20 21 22 38 8 7 44 43 42 41 40 39 16 17 29 30 31 32 33 23 24 25 26 27 28 36 35 34 9 PIC18F442037 RA3/AN3/VREF+ RA2/AN2/VREF-/CVREF RA0/AN0 RA1/AN1 MCLR/VPP/RE3 RB3/AN9/CCP2(1) RB4/KBI0/AN11 RB5/KBI1/PGM RB6/KBI2/PGC RB7/KBI3/PGD NC RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 RD1/PSP1 RD0/PSP0 RC3/SCK/SCL RC2/CCP1/P1A RC1/T1OSI/CCP2(1) RC0/T1OSO/T13CKI OSC2/CLKO/RA6 OSC1/CLKI/RA7 VSS VSS VDD VDD RE2/CS/AN7 RE1/WR/AN6 RE0/RD/AN5 RA5/AN4/SS/HLVDIN/C2OUT RA4/T0CKI/C1OUT RC7/RX/DT RD4/PSP4 RD5/PSP5/P1B RD6/PSP6/P1C RD7/PSP7/P1D VSS VDD VDD RB0/INT0/FLT0/AN12 RB1/INT1/AN10 RB2/INT2/AN8 44-pin QFN PIC18F4520 10 11 2 3 4 5 6 1 12 13 14 15 18 19 20 21 22 38 8 7 44 43 42 41 40 39 16 17 29 30 31 32 33 23 24 25 26 27 28 36 35 34 9 PIC18F442037 RA3/AN3/VREF+ RA2/AN2/VREF-/CVREF RA0/AN0 RA1/AN1 MCLR/VPP/RE3 NC RB4/KBI0/AN11 RB5/KBI1/PGM RB6/KBI2/PGC RB7/KBI3/PGD NC RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 RD1/PSP1 RD0/PSP0 RC3/SCK/SCL RC2/CCP1/P1A RC1/T1OSI/CCP2(1) NC NC RC0/T1OSO/T13CKI OSC2/CLKO/RA6 OSC1/CLKI/RA7 VSS VDD RE2/CS/AN7 RE1/WR/AN6 RE0/RD/AN5 RA5/AN4/SS/HLVDIN/C2OUT RA4/T0CKI/C1OUT RC7/RX/DT RD4/PSP4 RD5/PSP5/P1B RD6/PSP6/P1C RD7/PSP7/P1D VSS VDD RB0/INT0/FLT0/AN12 RB1/INT1/AN10 RB2/INT2/AN8 RB3/AN9/CCP2(1) 44-pin TQFP PIC18F4520PIC18F2420/2520/4420/4520 DS39631E-page 4 © 2008 Microchip Technology Inc. Table of Contents 1.0 Device Overview .......................................................................................................................................................................... 7 2.0 Oscillator Configurations ............................................................................................................................................................ 23 3.0 Power-Managed Modes ............................................................................................................................................................. 33 4.0 Reset .......................................................................................................................................................................................... 41 5.0 Memory Organization ................................................................................................................................................................. 53 6.0 Flash Program Memory.............................................................................................................................................................. 73 7.0 Data EEPROM Memory ............................................................................................................................................................. 83 8.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 89 9.0 Interrupts .................................................................................................................................................................................... 91 10.0 I/O Ports ................................................................................................................................................................................... 105 11.0 Timer0 Module ......................................................................................................................................................................... 123 12.0 Timer1 Module ......................................................................................................................................................................... 127 13.0 Timer2 Module ......................................................................................................................................................................... 133 14.0 Timer3 Module ......................................................................................................................................................................... 135 15.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 139 16.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 147 17.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 161 18.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 201 19.0 10-Bit Analog-to-Digital Converter (A/D) Module ..................................................................................................................... 223 20.0 Comparator Module.................................................................................................................................................................. 233 21.0 Comparator Voltage Reference Module................................................................................................................................... 239 22.0 High/Low-Voltage Detect (HLVD)............................................................................................................................................. 243 23.0 Special Features of the CPU.................................................................................................................................................... 249 24.0 Instruction Set Summary .......................................................................................................................................................... 267 25.0 Development Support............................................................................................................................................................... 317 26.0 Electrical Characteristics .......................................................................................................................................................... 321 27.0 DC and AC Characteristics Graphs and Tables....................................................................................................................... 361 28.0 Packaging Information.............................................................................................................................................................. 383 Appendix A: Revision History............................................................................................................................................................. 395 Appendix B: Device Differences......................................................................................................................................................... 395 Appendix C: Migration from Mid-Range to Enhanced Devices .......................................................................................................... 396 Appendix D: Migration from High-End to Enhanced Devices............................................................................................................. 396 Index .................................................................................................................................................................................................. 397 The Microchip Web Site ..................................................................................................................................................................... 407 Customer Change Notification Service .............................................................................................................................................. 407 Customer Support.............................................................................................................................................................................. 407 Reader Response .............................................................................................................................................................................. 408 PIC18F2420/2520/4420/4520 Product Identification System ............................................................................................................ 409© 2008 Microchip Technology Inc. DS39631E-page 5 PIC18F2420/2520/4420/4520 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000). Errata An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: • Microchip’s Worldwide Web site; http://www.microchip.com • Your local Microchip sales office (see last page) When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are using. Customer Notification System Register on our web site at www.microchip.com to receive the most current information on all of our products.PIC18F2420/2520/4420/4520 DS39631E-page 6 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 7 PIC18F2420/2520/4420/4520 1.0 DEVICE OVERVIEW This document contains device-specific information for the following devices: This family offers the advantages of all PIC18 microcontrollers – namely, high computational performance at an economical price – with the addition of high-endurance, Enhanced Flash program memory. On top of these features, the PIC18F2420/2520/4420/ 4520 family introduces design enhancements that make these microcontrollers a logical choice for many high-performance, power sensitive applications. 1.1 New Core Features 1.1.1 nanoWatt TECHNOLOGY All of the devices in the PIC18F2420/2520/4420/4520 family incorporate a range of features that can significantly reduce power consumption during operation. Key items include: • Alternate Run Modes: By clocking the controller from the Timer1 source or the internal oscillator block, power consumption during code execution can be reduced by as much as 90%. • Multiple Idle Modes: The controller can also run with its CPU core disabled but the peripherals still active. In these states, power consumption can be reduced even further, to as little as 4% of normal operation requirements. • On-the-Fly Mode Switching: The powermanaged modes are invoked by user code during operation, allowing the user to incorporate power-saving ideas into their application’s software design. • Low Consumption in Key Modules: The power requirements for both Timer1 and the Watchdog Timer are minimized. See Section 26.0 “Electrical Characteristics” for values. 1.1.2 MULTIPLE OSCILLATOR OPTIONS AND FEATURES All of the devices in the PIC18F2420/2520/4420/4520 family offer ten different oscillator options, allowing users a wide range of choices in developing application hardware. These include: • Four Crystal modes, using crystals or ceramic resonators • Two External Clock modes, offering the option of using two pins (oscillator input and a divide-by-4 clock output) or one pin (oscillator input, with the second pin reassigned as general I/O) • Two External RC Oscillator modes with the same pin options as the External Clock modes • An internal oscillator block which provides an 8 MHz clock and an INTRC source (approximately 31 kHz), as well as a range of 6 user-selectable clock frequencies, between 125 kHz to 4 MHz, for a total of 8 clock frequencies. This option frees the two oscillator pins for use as additional general purpose I/O. • A Phase Lock Loop (PLL) frequency multiplier, available to both the High-Speed Crystal and Internal Oscillator modes, which allows clock speeds of up to 40 MHz. Used with the internal oscillator, the PLL gives users a complete selection of clock speeds, from 31 kHz to 32 MHz – all without using an external crystal or clock circuit. Besides its availability as a clock source, the internal oscillator block provides a stable reference source that gives the family additional features for robust operation: • Fail-Safe Clock Monitor: This option constantly monitors the main clock source against a reference signal provided by the internal oscillator. If a clock failure occurs, the controller is switched to the internal oscillator block, allowing for continued low-speed operation or a safe application shutdown. • Two-Speed Start-up: This option allows the internal oscillator to serve as the clock source from Power-on Reset, or wake-up from Sleep mode, until the primary clock source is available. • PIC18F2420 • PIC18LF2420 • PIC18F2520 • PIC18LF2520 • PIC18F4420 • PIC18LF4420 • PIC18F4520 • PIC18LF4520PIC18F2420/2520/4420/4520 DS39631E-page 8 © 2008 Microchip Technology Inc. 1.2 Other Special Features • Memory Endurance: The Enhanced Flash cells for both program memory and data EEPROM are rated to last for many thousands of erase/write cycles – up to 100,000 for program memory and 1,000,000 for EEPROM. Data retention without refresh is conservatively estimated to be greater than 40 years. • Self-Programmability: These devices can write to their own program memory spaces under internal software control. By using a bootloader routine located in the protected Boot Block at the top of program memory, it becomes possible to create an application that can update itself in the field. • Extended Instruction Set: The PIC18F2420/ 2520/4420/4520 family introduces an optional extension to the PIC18 instruction set, which adds 8 new instructions and an Indexed Addressing mode. This extension, enabled as a device configuration option, has been specifically designed to optimize re-entrant application code originally developed in high-level languages, such as C. • Enhanced CCP Module: In PWM mode, this module provides 1, 2 or 4 modulated outputs for controlling half-bridge and full-bridge drivers. Other features include auto-shutdown, for disabling PWM outputs on interrupt, or other select conditions, and auto-restart to reactivate outputs once the condition has cleared. • Enhanced Addressable USART: This serial communication module is capable of standard RS-232 operation and provides support for the LIN bus protocol. Other enhancements include automatic baud rate detection and a 16-bit Baud Rate Generator for improved resolution. When the microcontroller is using the internal oscillator block, the EUSART provides stable operation for applications that talk to the outside world without using an external crystal (or its accompanying power requirement). • 10-Bit A/D Converter: This module incorporates programmable acquisition time, allowing for a channel to be selected and a conversion to be initiated without waiting for a sampling period and thus, reducing code overhead. • Extended Watchdog Timer (WDT): This enhanced version incorporates a 16-bit prescaler, allowing an extended time-out range that is stable across operating voltage and temperature. See Section 26.0 “Electrical Characteristics” for time-out periods. 1.3 Details on Individual Family Members Devices in the PIC18F2420/2520/4420/4520 family are available in 28-pin and 40/44-pin packages. Block diagrams for the two groups are shown in Figure 1-1 and Figure 1-2. The devices are differentiated from each other in five ways: 1. Flash program memory (16 Kbytes for PIC18F2420/4420 devices and 32 Kbytes for PIC18F2520/4520 devices). 2. A/D channels (10 for 28-pin devices, 13 for 40/44-pin devices). 3. I/O ports (3 bidirectional ports on 28-pin devices, 5 bidirectional ports on 40/44-pin devices). 4. CCP and Enhanced CCP implementation (28-pin devices have 2 standard CCP modules, 40/44-pin devices have one standard CCP module and one ECCP module). 5. Parallel Slave Port (present only on 40/44-pin devices). All other features for devices in this family are identical. These are summarized in Table 1-1. The pinouts for all devices are listed in Table 1-2 and Table 1-3. Like all Microchip PIC18 devices, members of the PIC18F2420/2520/4420/4520 family are available as both standard and low-voltage devices. Standard devices with Enhanced Flash memory, designated with an “F” in the part number (such as PIC18F2420), accommodate an operating VDD range of 4.2V to 5.5V. Low-voltage parts, designated by “LF” (such as PIC18LF2420), function over an extended VDD range of 2.0V to 5.5V. © 2008 Microchip Technology Inc. DS39631E-page 9 PIC18F2420/2520/4420/4520 TABLE 1-1: DEVICE FEATURES Features PIC18F2420 PIC18F2520 PIC18F4420 PIC18F4520 Operating Frequency DC – 40 MHz DC – 40 MHz DC – 40 MHz DC – 40 MHz Program Memory (Bytes) 16384 32768 16384 32768 Program Memory (Instructions) 8192 16384 8192 16384 Data Memory (Bytes) 768 1536 768 1536 Data EEPROM Memory (Bytes) 256 256 256 256 Interrupt Sources 19 19 20 20 I/O Ports Ports A, B, C, (E) Ports A, B, C, (E) Ports A, B, C, D, E Ports A, B, C, D, E Timers 4 4 4 4 Capture/Compare/PWM Modules 2 2 1 1 Enhanced Capture/Compare/PWM Modules 0011 Serial Communications MSSP, Enhanced USART MSSP, Enhanced USART MSSP, Enhanced USART MSSP, Enhanced USART Parallel Communications (PSP) No No Yes Yes 10-Bit Analog-to-Digital Module 10 Input Channels 10 Input Channels 13 Input Channels 13 Input Channels Resets (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST), MCLR (optional), WDT POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST), MCLR (optional), WDT POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST), MCLR (optional), WDT POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST), MCLR (optional), WDT Programmable High/Low-Voltage Detect Yes Yes Yes Yes Programmable Brown-out Reset Yes Yes Yes Yes Instruction Set 75 Instructions; 83 with Extended Instruction Set Enabled 75 Instructions; 83 with Extended Instruction Set Enabled 75 Instructions; 83 with Extended Instruction Set Enabled 75 Instructions; 83 with Extended Instruction Set Enabled Packages 28-Pin SPDIP 28-Pin SOIC 28-Pin QFN 28-Pin SPDIP 28-Pin SOIC 28-Pin QFN 40-Pin PDIP 44-Pin QFN 44-Pin TQFP 40-Pin PDIP 44-Pin QFN 44-Pin TQFPPIC18F2420/2520/4420/4520 DS39631E-page 10 © 2008 Microchip Technology Inc. FIGURE 1-1: PIC18F2420/2520 (28-PIN) BLOCK DIAGRAM Instruction Decode and Control PORTA PORTB PORTC RA4/T0CKI/C1OUT RA5/AN4/SS/HLVDIN/C2OUT RB0/INT0/FLT0/AN12 RC0/T1OSO/T13CKI RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT RA3/AN3/VREF+ RA2/AN2/VREF-/CVREF RA1/AN1 RA0/AN0 RB1/INT1/AN10 Data Latch Data Memory ( 3.9 Kbytes ) Address Latch Data Address<12> 12 BSR Access FSR0 FSR1 FSR2 inc/dec logic Address 4 12 4 PCH PCL PCLATH 8 31-Level Stack Program Counter PRODH PRODL 8 x 8 Multiply 8 BITOP 8 8 ALU<8> Address Latch Program Memory (16/32 Kbytes) Data Latch 20 8 8 Table Pointer<21> inc/dec logic 21 8 Data Bus<8> Table Latch 8 IR 12 3 ROM Latch RB2/INT2/AN8 RB3/AN9/CCP2(1) PCLATU PCU OSC2/CLKO(3)/RA6 Note 1: CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set, or RB3 when CCP2MX is not set. 2: RE3 is only available when MCLR functionality is disabled. 3: OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O. Refer to Section 2.0 “Oscillator Configurations” for additional information. RB4/KBI0/AN11 RB5/KBI1/PGM RB6/KBI2/PGC RB7/KBI3/PGD Comparator MSSP EUSART 10-Bit ADC Timer0 Timer1 Timer2 Timer3 CCP2 HLVD CCP1 BOR Data EEPROM W Instruction Bus <16> STKPTR Bank 8 State Machine Control Signals Decode 8 8 Power-up Timer Oscillator Start-up Timer Power-on Reset Watchdog Timer OSC1(3) OSC2(3) VDD, Brown-out Reset Internal Oscillator Fail-Safe Clock Monitor Precision Reference Band Gap VSS MCLR(2) Block INTRC Oscillator 8 MHz Oscillator Single-Supply Programming In-Circuit Debugger T1OSO OSC1/CLKI(3)/RA7 T1OSI PORTE MCLR/VPP/RE3(2)© 2008 Microchip Technology Inc. DS39631E-page 11 PIC18F2420/2520/4420/4520 FIGURE 1-2: PIC18F4420/4520 (40/44-PIN) BLOCK DIAGRAM Instruction Decode and Control Data Latch Data Memory ( 3.9 Kbytes ) Address Latch Data Address<12> 12 BSR Access FSR0 FSR1 FSR2 inc/dec logic Address 4 12 4 PCH PCL PCLATH 8 31-Level Stack Program Counter PRODH PRODL 8 x 8 Multiply 8 BITOP 8 8 ALU<8> Address Latch Program Memory (16/32 Kbytes) Data Latch 20 8 8 Table Pointer<21> inc/dec logic 21 8 Data Bus<8> Table Latch 8 IR 12 3 ROM Latch PORTD RD0/PSP0 PCLATU PCU PORTE MCLR/VPP/RE3(2) RE2/CS/AN7 RE0/RD/AN5 RE1/WR/AN6 Note 1: CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set, or RB3 when CCP2MX is not set. 2: RE3 is only available when MCLR functionality is disabled. 3: OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O. Refer to Section 2.0 “Oscillator Configurations” for additional information. :RD4/PSP4 Comparator MSSP EUSART 10-Bit ADC Timer0 Timer1 Timer2 Timer3 CCP2 HLVD ECCP1 BOR Data EEPROM W Instruction Bus <16> STKPTR Bank 8 State Machine Control Signals Decode 8 8 Power-up Timer Oscillator Start-up Timer Power-on Reset Watchdog Timer OSC1(3) OSC2(3) VDD, Brown-out Reset Internal Oscillator Fail-Safe Clock Monitor Precision Reference Band Gap VSS MCLR(2) Block INTRC Oscillator 8 MHz Oscillator Single-Supply Programming In-Circuit Debugger T1OSI T1OSO RD5/PSP5/P1B RD6/PSP6/P1C RD7/PSP7/P1D PORTA PORTB PORTC RA4/T0CKI/C1OUT RA5/AN4/SS/HLVDIN/C2OUT RB0/INT0/FLT0/AN12 RC0/T1OSO/T13CKI RC1/T1OSI/CCP2(1) RC2/CCP1/P1A RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT RA3/AN3/VREF+ RA2/AN2/VREF-/CVREF RA1/AN1 RA0/AN0 RB1/INT1/AN10 RB2/INT2/AN8 RB3/AN9/CCP2(1) OSC2/CLKO(3)/RA6 RB4/KBI0/AN11 RB5/KBI1/PGM RB6/KBI2/PGC RB7/KBI3/PGD OSC1/CLKI(3)/RA7PIC18F2420/2520/4420/4520 DS39631E-page 12 © 2008 Microchip Technology Inc. TABLE 1-2: PIC18F2420/2520 PINOUT I/O DESCRIPTIONS Pin Name Pin Number Pin Type Buffer Type SPDIP, Description SOIC QFN MCLR/VPP/RE3 MCLR VPP RE3 1 26 I P I ST ST Master Clear (input) or programming voltage (input). Master Clear (Reset) input. This pin is an active-low Reset to the device. Programming voltage input. Digital input. OSC1/CLKI/RA7 OSC1 CLKI RA7 9 6 I I I/O ST CMOS TTL Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode; CMOS otherwise. External clock source input. Always associated with pin function, OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) General purpose I/O pin. OSC2/CLKO/RA6 OSC2 CLKO RA6 10 7 O O I/O — — TTL Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General purpose I/O pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. © 2008 Microchip Technology Inc. DS39631E-page 13 PIC18F2420/2520/4420/4520 PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 2 27 I/O I TTL Analog Digital I/O. Analog input 0. RA1/AN1 RA1 AN1 3 28 I/O I TTL Analog Digital I/O. Analog input 1. RA2/AN2/VREF-/CVREF RA2 AN2 VREFCVREF 4 1 I/O I I O TTL Analog Analog Analog Digital I/O. Analog input 2. A/D reference voltage (low) input. Comparator reference voltage output. RA3/AN3/VREF+ RA3 AN3 VREF+ 5 2 I/O I I TTL Analog Analog Digital I/O. Analog input 3. A/D reference voltage (high) input. RA4/T0CKI/C1OUT RA4 T0CKI C1OUT 6 3 I/O I O ST ST — Digital I/O. Timer0 external clock input. Comparator 1 output. RA5/AN4/SS/HLVDIN/ C2OUT RA5 AN4 SS HLVDIN C2OUT 7 4 I/O I I I O TTL Analog TTL Analog — Digital I/O. Analog input 4. SPI slave select input. High/Low-Voltage Detect input. Comparator 2 output. RA6 See the OSC2/CLKO/RA6 pin. RA7 See the OSC1/CLKI/RA7 pin. TABLE 1-2: PIC18F2420/2520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type SPDIP, Description SOIC QFN Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. PIC18F2420/2520/4420/4520 DS39631E-page 14 © 2008 Microchip Technology Inc. PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0/FLT0/AN12 RB0 INT0 FLT0 AN12 21 18 I/O I I I TTL ST ST Analog Digital I/O. External interrupt 0. PWM Fault input for CCP1. Analog input 12. RB1/INT1/AN10 RB1 INT1 AN10 22 19 I/O I I TTL ST Analog Digital I/O. External interrupt 1. Analog input 10. RB2/INT2/AN8 RB2 INT2 AN8 23 20 I/O I I TTL ST Analog Digital I/O. External interrupt 2. Analog input 8. RB3/AN9/CCP2 RB3 AN9 CCP2(1) 24 21 I/O I I/O TTL Analog ST Digital I/O. Analog input 9. Capture 2 input/Compare 2 output/PWM2 output. RB4/KBI0/AN11 RB4 KBI0 AN11 25 22 I/O I I TTL TTL Analog Digital I/O. Interrupt-on-change pin. Analog input 11. RB5/KBI1/PGM RB5 KBI1 PGM 26 23 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. Low-Voltage ICSP™ Programming enable pin. RB6/KBI2/PGC RB6 KBI2 PGC 27 24 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming clock pin. RB7/KBI3/PGD RB7 KBI3 PGD 28 25 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. TABLE 1-2: PIC18F2420/2520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type SPDIP, Description SOIC QFN Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. © 2008 Microchip Technology Inc. DS39631E-page 15 PIC18F2420/2520/4420/4520 PORTC is a bidirectional I/O port. RC0/T1OSO/T13CKI RC0 T1OSO T13CKI 11 8 I/O O I ST — ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. RC1/T1OSI/CCP2 RC1 T1OSI CCP2(2) 12 9 I/O I I/O ST Analog ST Digital I/O. Timer1 oscillator input. Capture 2 input/Compare 2 output/PWM2 output. RC2/CCP1 RC2 CCP1 13 10 I/O I/O ST ST Digital I/O. Capture 1 input/Compare 1 output/PWM1 output. RC3/SCK/SCL RC3 SCK SCL 14 11 I/O I/O I/O ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2C™ mode. RC4/SDI/SDA RC4 SDI SDA 15 12 I/O I I/O ST ST ST Digital I/O. SPI data in. I 2C data I/O. RC5/SDO RC5 SDO 16 13 I/O O ST — Digital I/O. SPI data out. RC6/TX/CK RC6 TX CK 17 14 I/O O I/O ST — ST Digital I/O. EUSART asynchronous transmit. EUSART synchronous clock (see related RX/DT). RC7/RX/DT RC7 RX DT 18 15 I/O I I/O ST ST ST Digital I/O. EUSART asynchronous receive. EUSART synchronous data (see related TX/CK). RE3 — — — — See MCLR/VPP/RE3 pin. VSS 8, 19 5, 16 P — Ground reference for logic and I/O pins. VDD 20 17 P — Positive supply for logic and I/O pins. TABLE 1-2: PIC18F2420/2520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type SPDIP, Description SOIC QFN Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. PIC18F2420/2520/4420/4520 DS39631E-page 16 © 2008 Microchip Technology Inc. TABLE 1-3: PIC18F4420/4520 PINOUT I/O DESCRIPTIONS Pin Name Pin Number Pin Type Buffer Type Description PDIP QFN TQFP MCLR/VPP/RE3 MCLR VPP RE3 1 18 18 I P I ST ST Master Clear (input) or programming voltage (input). Master Clear (Reset) input. This pin is an active-low Reset to the device. Programming voltage input. Digital input. OSC1/CLKI/RA7 OSC1 CLKI RA7 13 32 30 I I I/O ST CMOS TTL Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode; analog otherwise. External clock source input. Always associated with pin function, OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) General purpose I/O pin. OSC2/CLKO/RA6 OSC2 CLKO RA6 14 33 31 O O I/O — — TTL Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General purpose I/O pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. © 2008 Microchip Technology Inc. DS39631E-page 17 PIC18F2420/2520/4420/4520 PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 2 19 19 I/O I TTL Analog Digital I/O. Analog input 0. RA1/AN1 RA1 AN1 3 20 20 I/O I TTL Analog Digital I/O. Analog input 1. RA2/AN2/VREF-/CVREF RA2 AN2 VREFCVREF 4 21 21 I/O I I O TTL Analog Analog Analog Digital I/O. Analog input 2. A/D reference voltage (low) input. Comparator reference voltage output. RA3/AN3/VREF+ RA3 AN3 VREF+ 5 22 22 I/O I I TTL Analog Analog Digital I/O. Analog input 3. A/D reference voltage (high) input. RA4/T0CKI/C1OUT RA4 T0CKI C1OUT 6 23 23 I/O I O ST ST — Digital I/O. Timer0 external clock input. Comparator 1 output. RA5/AN4/SS/HLVDIN/ C2OUT RA5 AN4 SS HLVDIN C2OUT 7 24 24 I/O I I I O TTL Analog TTL Analog — Digital I/O. Analog input 4. SPI slave select input. High/Low-Voltage Detect input. Comparator 2 output. RA6 See the OSC2/CLKO/RA6 pin. RA7 See the OSC1/CLKI/RA7 pin. TABLE 1-3: PIC18F4420/4520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description PDIP QFN TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. PIC18F2420/2520/4420/4520 DS39631E-page 18 © 2008 Microchip Technology Inc. PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0/FLT0/AN12 RB0 INT0 FLT0 AN12 33 9 8 I/O I I I TTL ST ST Analog Digital I/O. External interrupt 0. PWM Fault input for Enhanced CCP1. Analog input 12. RB1/INT1/AN10 RB1 INT1 AN10 34 10 9 I/O I I TTL ST Analog Digital I/O. External interrupt 1. Analog input 10. RB2/INT2/AN8 RB2 INT2 AN8 35 11 10 I/O I I TTL ST Analog Digital I/O. External interrupt 2. Analog input 8. RB3/AN9/CCP2 RB3 AN9 CCP2(1) 36 12 11 I/O I I/O TTL Analog ST Digital I/O. Analog input 9. Capture 2 input/Compare 2 output/PWM2 output. RB4/KBI0/AN11 RB4 KBI0 AN11 37 14 14 I/O I I TTL TTL Analog Digital I/O. Interrupt-on-change pin. Analog input 11. RB5/KBI1/PGM RB5 KBI1 PGM 38 15 15 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. Low-Voltage ICSP™ Programming enable pin. RB6/KBI2/PGC RB6 KBI2 PGC 39 16 16 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming clock pin. RB7/KBI3/PGD RB7 KBI3 PGD 40 17 17 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. TABLE 1-3: PIC18F4420/4520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description PDIP QFN TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. © 2008 Microchip Technology Inc. DS39631E-page 19 PIC18F2420/2520/4420/4520 PORTC is a bidirectional I/O port. RC0/T1OSO/T13CKI RC0 T1OSO T13CKI 15 34 32 I/O O I ST — ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. RC1/T1OSI/CCP2 RC1 T1OSI CCP2(2) 16 35 35 I/O I I/O ST CMOS ST Digital I/O. Timer1 oscillator input. Capture 2 input/Compare 2 output/PWM2 output. RC2/CCP1/P1A RC2 CCP1 P1A 17 36 36 I/O I/O O ST ST — Digital I/O. Capture 1 input/Compare 1 output/PWM1 output. Enhanced CCP1 output. RC3/SCK/SCL RC3 SCK SCL 18 37 37 I/O I/O I/O ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2C™ mode. RC4/SDI/SDA RC4 SDI SDA 23 42 42 I/O I I/O ST ST ST Digital I/O. SPI data in. I 2C data I/O. RC5/SDO RC5 SDO 24 43 43 I/O O ST — Digital I/O. SPI data out. RC6/TX/CK RC6 TX CK 25 44 44 I/O O I/O ST — ST Digital I/O. EUSART asynchronous transmit. EUSART synchronous clock (see related RX/DT). RC7/RX/DT RC7 RX DT 26 1 1 I/O I I/O ST ST ST Digital I/O. EUSART asynchronous receive. EUSART synchronous data (see related TX/CK). TABLE 1-3: PIC18F4420/4520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description PDIP QFN TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. PIC18F2420/2520/4420/4520 DS39631E-page 20 © 2008 Microchip Technology Inc. PORTD is a bidirectional I/O port or a Parallel Slave Port (PSP) for interfacing to a microprocessor port. These pins have TTL input buffers when PSP module is enabled. RD0/PSP0 RD0 PSP0 19 38 38 I/O I/O ST TTL Digital I/O. Parallel Slave Port data. RD1/PSP1 RD1 PSP1 20 39 39 I/O I/O ST TTL Digital I/O. Parallel Slave Port data. RD2/PSP2 RD2 PSP2 21 40 40 I/O I/O ST TTL Digital I/O. Parallel Slave Port data. RD3/PSP3 RD3 PSP3 22 41 41 I/O I/O ST TTL Digital I/O. Parallel Slave Port data. RD4/PSP4 RD4 PSP4 27 2 2 I/O I/O ST TTL Digital I/O. Parallel Slave Port data. RD5/PSP5/P1B RD5 PSP5 P1B 28 3 3 I/O I/O O ST TTL — Digital I/O. Parallel Slave Port data. Enhanced CCP1 output. RD6/PSP6/P1C RD6 PSP6 P1C 29 4 4 I/O I/O O ST TTL — Digital I/O. Parallel Slave Port data. Enhanced CCP1 output. RD7/PSP7/P1D RD7 PSP7 P1D 30 5 5 I/O I/O O ST TTL — Digital I/O. Parallel Slave Port data. Enhanced CCP1 output. TABLE 1-3: PIC18F4420/4520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description PDIP QFN TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. © 2008 Microchip Technology Inc. DS39631E-page 21 PIC18F2420/2520/4420/4520 PORTE is a bidirectional I/O port. RE0/RD/AN5 RE0 RD AN5 8 25 25 I/O I I ST TTL Analog Digital I/O. Read control for Parallel Slave Port (see also WR and CS pins). Analog input 5. RE1/WR/AN6 RE1 WR AN6 9 26 26 I/O I I ST TTL Analog Digital I/O. Write control for Parallel Slave Port (see CS and RD pins). Analog input 6. RE2/CS/AN7 RE2 CS AN7 10 27 27 I/O I I ST TTL Analog Digital I/O. Chip Select control for Parallel Slave Port (see related RD and WR). Analog input 7. RE3 — — — — — See MCLR/VPP/RE3 pin. VSS 12, 31 6, 30, 31 6, 29 P — Ground reference for logic and I/O pins. VDD 11, 32 7, 8, 28, 29 7, 28 P — Positive supply for logic and I/O pins. NC — 13 12, 13, 33, 34 — — No Connect. TABLE 1-3: PIC18F4420/4520 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description PDIP QFN TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared. PIC18F2420/2520/4420/4520 DS39631E-page 22 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 23 PIC18F2420/2520/4420/4520 2.0 OSCILLATOR CONFIGURATIONS 2.1 Oscillator Types PIC18F2420/2520/4420/4520 devices can be operated in ten different oscillator modes. The user can program the Configuration bits, FOSC<3:0>, in Configuration Register 1H to select one of these ten modes: 1. LP Low-Power Crystal 2. XT Crystal/Resonator 3. HS High-Speed Crystal/Resonator 4. HSPLL High-Speed Crystal/Resonator with PLL Enabled 5. RC External Resistor/Capacitor with FOSC/4 Output on RA6 6. RCIO External Resistor/Capacitor with I/O on RA6 7. INTIO1 Internal Oscillator with FOSC/4 Output on RA6 and I/O on RA7 8. INTIO2 Internal Oscillator with I/O on RA6 and RA7 9. EC External Clock with FOSC/4 Output 10. ECIO External Clock with I/O on RA6 2.2 Crystal Oscillator/Ceramic Resonators In XT, LP, HS or HSPLL Oscillator modes, a crystal or ceramic resonator is connected to the OSC1 and OSC2 pins to establish oscillation. Figure 2-1 shows the pin connections. The oscillator design requires the use of a parallel cut crystal. FIGURE 2-1: CRYSTAL/CERAMIC RESONATOR OPERATION (XT, LP, HS OR HSPLL CONFIGURATION) TABLE 2-1: CAPACITOR SELECTION FOR CERAMIC RESONATORS Note: Use of a series cut crystal may give a frequency out of the crystal manufacturer’s specifications. Typical Capacitor Values Used: Mode Freq OSC1 OSC2 XT 3.58 MHz 4.19 MHz 4 MHz 4 MHz 15 pF 15 pF 30 pF 50 pF 15 pF 15 pF 30 pF 50 pF Capacitor values are for design guidance only. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. See the notes following Table 2-2 for additional information. Note: When using resonators with frequencies above 3.5 MHz, the use of HS mode, rather than XT mode, is recommended. HS mode may be used at any VDD for which the controller is rated. If HS is selected, it is possible that the gain of the oscillator will overdrive the resonator. Therefore, a series resistor should be placed between the OSC2 pin and the resonator. As a good starting point, the recommended value of RS is 330Ω. Note 1: See Table 2-1 and Table 2-2 for initial values of C1 and C2. 2: A series resistor (RS) may be required for AT strip cut crystals. 3: RF varies with the oscillator mode chosen. C1(1) C2(1) XTAL OSC2 OSC1 RF(3) Sleep To Logic PIC18FXXXX RS(2) InternalPIC18F2420/2520/4420/4520 DS39631E-page 24 © 2008 Microchip Technology Inc. TABLE 2-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR An external clock source may also be connected to the OSC1 pin in the HS mode, as shown in Figure 2-2. FIGURE 2-2: EXTERNAL CLOCK INPUT OPERATION (HS OSC CONFIGURATION) 2.3 External Clock Input The EC and ECIO Oscillator modes require an external clock source to be connected to the OSC1 pin. There is no oscillator start-up time required after a Power-on Reset or after an exit from Sleep mode. In the EC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 2-3 shows the pin connections for the EC Oscillator mode. FIGURE 2-3: EXTERNAL CLOCK INPUT OPERATION (EC CONFIGURATION) The ECIO Oscillator mode functions like the EC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). Figure 2-4 shows the pin connections for the ECIO Oscillator mode. FIGURE 2-4: EXTERNAL CLOCK INPUT OPERATION (ECIO CONFIGURATION) Osc Type Crystal Freq Typical Capacitor Values Tested: C1 C2 LP 32 kHz 30 pF 30 pF XT 1 MHz 4 MHz 15 pF 15 pF 15 pF 15 pF HS 4 MHz 10 MHz 20 MHz 25 MHz 25 MHz 15 pF 15 pF 15 pF 0 pF 15 pF 15 pF 15 pF 15 pF 5 pF 15 pF Capacitor values are for design guidance only. These capacitors were tested with the crystals listed below for basic start-up and operation. These values are not optimized. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. See the notes following this table for additional information. Crystals Used: 32 kHz 4 MHz 25 MHz 10 MHz 1 MHz 20 MHz Note 1: Higher capacitance increases the stability of the oscillator but also increases the start-up time. 2: When operating below 3V VDD, or when using certain ceramic resonators at any voltage, it may be necessary to use the HS mode or switch to a crystal oscillator. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Rs may be required to avoid overdriving crystals with low drive level specification. 5: Always verify oscillator performance over the VDD and temperature range that is expected for the application. OSC1 Open OSC2 Clock from Ext. System PIC18FXXXX (HS Mode) OSC1/CLKI FOSC/4 OSC2/CLKO Clock from Ext. System PIC18FXXXX OSC1/CLKI RA6 I/O (OSC2) Clock from Ext. System PIC18FXXXX© 2008 Microchip Technology Inc. DS39631E-page 25 PIC18F2420/2520/4420/4520 2.4 RC Oscillator For timing insensitive applications, the “RC” and “RCIO” device options offer additional cost savings. The actual oscillator frequency is a function of several factors: • supply voltage • values of the external resistor (REXT) and capacitor (CEXT) • operating temperature Given the same device, operating voltage and temperature and component values, there will also be unit-to-unit frequency variations. These are due to factors such as: • normal manufacturing variation • difference in lead frame capacitance between package types (especially for low CEXT values) • variations within the tolerance of limits of REXT and CEXT In the RC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 2-5 shows how the R/C combination is connected. FIGURE 2-5: RC OSCILLATOR MODE The RCIO Oscillator mode (Figure 2-6) functions like the RC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). FIGURE 2-6: RCIO OSCILLATOR MODE 2.5 PLL Frequency Multiplier A Phase Locked Loop (PLL) circuit is provided as an option for users who wish to use a lower frequency oscillator circuit or to clock the device up to its highest rated frequency from a crystal oscillator. This may be useful for customers who are concerned with EMI due to high-frequency crystals or users who require higher clock speeds from an internal oscillator. 2.5.1 HSPLL OSCILLATOR MODE The HSPLL mode makes use of the HS Oscillator mode for frequencies up to 10 MHz. A PLL then multiplies the oscillator output frequency by 4 to produce an internal clock frequency up to 40 MHz. The PLLEN bit is not available in this oscillator mode. The PLL is only available to the crystal oscillator when the FOSC<3:0> Configuration bits are programmed for HSPLL mode (= 0110). FIGURE 2-7: PLL BLOCK DIAGRAM (HS MODE) 2.5.2 PLL AND INTOSC The PLL is also available to the internal oscillator block in selected oscillator modes. In this configuration, the PLL is enabled in software and generates a clock output of up to 32 MHz. The operation of INTOSC with the PLL is described in Section 2.6.4 “PLL in INTOSC Modes”. OSC2/CLKO CEXT REXT PIC18FXXXX OSC1 FOSC/4 Internal Clock VDD VSS Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ CEXT > 20 pF CEXT REXT PIC18FXXXX OSC1 Internal Clock VDD VSS Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ CEXT > 20 pF RA6 I/O (OSC2) MUX VCO Loop Filter Crystal Osc OSC2 OSC1 PLL Enable FIN FOUT SYSCLK Phase Comparator HS Oscillator Enable ÷4 (from Configuration Register 1H) HS ModePIC18F2420/2520/4420/4520 DS39631E-page 26 © 2008 Microchip Technology Inc. 2.6 Internal Oscillator Block The PIC18F2420/2520/4420/4520 devices include an internal oscillator block which generates two different clock signals; either can be used as the microcontroller’s clock source. This may eliminate the need for external oscillator circuits on the OSC1 and/or OSC2 pins. The main output (INTOSC) is an 8 MHz clock source which can be used to directly drive the device clock. It also drives a postscaler which can provide a range of clock frequencies from 31 kHz to 4 MHz. The INTOSC output is enabled when a clock frequency from 125 kHz to 8 MHz is selected. The other clock source is the internal RC oscillator (INTRC), which provides a nominal 31 kHz output. INTRC is enabled if it is selected as the device clock source; it is also enabled automatically when any of the following are enabled: • Power-up Timer • Fail-Safe Clock Monitor • Watchdog Timer • Two-Speed Start-up These features are discussed in greater detail in Section 23.0 “Special Features of the CPU”. The clock source frequency (INTOSC direct, INTRC direct or INTOSC postscaler) is selected by configuring the IRCF bits of the OSCCON register (page 30). 2.6.1 INTIO MODES Using the internal oscillator as the clock source eliminates the need for up to two external oscillator pins, which can then be used for digital I/O. Two distinct configurations are available: • In INTIO1 mode, the OSC2 pin outputs FOSC/4, while OSC1 functions as RA7 for digital input and output. • In INTIO2 mode, OSC1 functions as RA7 and OSC2 functions as RA6, both for digital input and output. 2.6.2 INTOSC OUTPUT FREQUENCY The internal oscillator block is calibrated at the factory to produce an INTOSC output frequency of 8.0 MHz. The INTRC oscillator operates independently of the INTOSC source. Any changes in INTOSC across voltage and temperature are not necessarily reflected by changes in INTRC and vice versa. 2.6.3 OSCTUNE REGISTER The internal oscillator’s output has been calibrated at the factory but can be adjusted in the user’s application. This is done by writing to the OSCTUNE register (Register 2-1). When the OSCTUNE register is modified, the INTOSC frequency will begin shifting to the new frequency. The INTRC clock will reach the new frequency within 8 clock cycles (approximately 8 * 32 μs = 256 μs). The INTOSC clock will stabilize within 1 ms. Code execution continues during this shift. There is no indication that the shift has occurred. The OSCTUNE register also implements the INTSRC and PLLEN bits, which control certain features of the internal oscillator block. The INTSRC bit allows users to select which internal oscillator provides the clock source when the 31 kHz frequency option is selected. This is covered in greater detail in Section 2.7.1 “Oscillator Control Register”. The PLLEN bit controls the operation of the frequency multiplier, PLL, in internal oscillator modes. 2.6.4 PLL IN INTOSC MODES The 4x frequency multiplier can be used with the internal oscillator block to produce faster device clock speeds than are normally possible with an internal oscillator. When enabled, the PLL produces a clock speed of up to 32 MHz. Unlike HSPLL mode, the PLL is controlled through software. The control bit, PLLEN (OSCTUNE<6>), is used to enable or disable its operation. The PLL is available when the device is configured to use the internal oscillator block as its primary clock source (FOSC<3:0> = 1001 or 1000). Additionally, the PLL will only function when the selected output frequency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111 or 110). If both of these conditions are not met, the PLL is disabled. The PLLEN control bit is only functional in those internal oscillator modes where the PLL is available. In all other modes, it is forced to ‘0’ and is effectively unavailable. 2.6.5 INTOSC FREQUENCY DRIFT The factory calibrates the internal oscillator block output (INTOSC) for 8 MHz. However, this frequency may drift as VDD or temperature changes, which can affect the controller operation in a variety of ways. It is possible to adjust the INTOSC frequency by modifying the value in the OSCTUNE register. This has no effect on the INTRC clock source frequency. Tuning the INTOSC source requires knowing when to make the adjustment, in which direction it should be made, and in some cases, how large a change is needed. Three compensation techniques are discussed in Section 2.6.5.1 “Compensating with the EUSART”, Section 2.6.5.2 “Compensating with the Timers” and Section 2.6.5.3 “Compensating with the CCP Module in Capture Mode”, but other techniques may be used.© 2008 Microchip Technology Inc. DS39631E-page 27 PIC18F2420/2520/4420/4520 2.6.5.1 Compensating with the EUSART An adjustment may be required when the EUSART begins to generate framing errors or receives data with errors while in Asynchronous mode. Framing errors indicate that the device clock frequency is too high. To adjust for this, decrement the value in OSCTUNE to reduce the clock frequency. On the other hand, errors in data may suggest that the clock speed is too low. To compensate, increment OSCTUNE to increase the clock frequency. 2.6.5.2 Compensating with the Timers This technique compares device clock speed to some reference clock. Two timers may be used; one timer is clocked by the peripheral clock, while the other is clocked by a fixed reference source, such as the Timer1 oscillator. Both timers are cleared, but the timer clocked by the reference generates interrupts. When an interrupt occurs, the internally clocked timer is read and both timers are cleared. If the internally clocked timer value is greater than expected, then the internal oscillator block is running too fast. To adjust for this, decrement the OSCTUNE register. 2.6.5.3 Compensating with the CCP Module in Capture Mode A CCP module can use free-running Timer1 (or Timer3), clocked by the internal oscillator block and an external event with a known period (i.e., AC power frequency). The time of the first event is captured in the CCPRxH:CCPRxL registers and is recorded for use later. When the second event causes a capture, the time of the first event is subtracted from the time of the second event. Since the period of the external event is known, the time difference between events can be calculated. If the measured time is much greater than the calculated time, the internal oscillator block is running too fast; to compensate, decrement the OSCTUNE register. If the measured time is much less than the calculated time, the internal oscillator block is running too slow; to compensate, increment the OSCTUNE register. REGISTER 2-1: OSCTUNE: OSCILLATOR TUNING REGISTER R/W-0 R/W-0(1) U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 INTSRC PLLEN(1) — TUN4 TUN3 TUN2 TUN1 TUN0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 INTSRC: Internal Oscillator Low-Frequency Source Select bit 1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled) 0 = 31 kHz device clock derived directly from INTRC internal oscillator bit 6 PLLEN: Frequency Multiplier PLL for INTOSC Enable bit(1) 1 = PLL enabled for INTOSC (4 MHz and 8 MHz only) 0 = PLL disabled bit 5 Unimplemented: Read as ‘0’ bit 4-0 TUN<4:0>: Frequency Tuning bits 011111 = Maximum frequency • • • • 000001 000000 = Center frequency. Oscillator module is running at the calibrated frequency. 111111 • • • • 100000 = Minimum frequency Note 1: Available only in certain oscillator configurations; otherwise, this bit is unavailable and reads as ‘0’. See Section 2.6.4 “PLL in INTOSC Modes” for details.PIC18F2420/2520/4420/4520 DS39631E-page 28 © 2008 Microchip Technology Inc. 2.7 Clock Sources and Oscillator Switching Like previous PIC18 devices, the PIC18F2420/2520/ 4420/4520 family includes a feature that allows the device clock source to be switched from the main oscillator to an alternate low-frequency clock source. PIC18F2420/2520/4420/4520 devices offer two alternate clock sources. When an alternate clock source is enabled, the various power-managed operating modes are available. Essentially, there are three clock sources for these devices: • Primary oscillators • Secondary oscillators • Internal oscillator block The primary oscillators include the External Crystal and Resonator modes, the External RC modes, the External Clock modes and the internal oscillator block. The particular mode is defined by the FOSC<3:0> Configuration bits. The details of these modes are covered earlier in this chapter. The secondary oscillators are those external sources not connected to the OSC1 or OSC2 pins. These sources may continue to operate even after the controller is placed in a power-managed mode. PIC18F2420/2520/4420/4520 devices offer the Timer1 oscillator as a secondary oscillator. This oscillator, in all power-managed modes, is often the time base for functions such as a Real-Time Clock (RTC). Most often, a 32.768 kHz watch crystal is connected between the RC0/T1OSO/T13CKI and RC1/T1OSI pins. Like the LP Oscillator mode circuit, loading capacitors are also connected from each pin to ground. The Timer1 oscillator is discussed in greater detail in Section 12.3 “Timer1 Oscillator”. In addition to being a primary clock source, the internal oscillator block is available as a power-managed mode clock source. The INTRC source is also used as the clock source for several special features, such as the WDT and Fail-Safe Clock Monitor. The clock sources for the PIC18F2420/2520/4420/4520 devices are shown in Figure 2-8. See Section 23.0 “Special Features of the CPU” for Configuration register details. FIGURE 2-8: PIC18F2420/2520/4420/4520 CLOCK DIAGRAM 4 x PLL FOSC<3:0> Secondary Oscillator T1OSCEN Enable Oscillator T1OSO T1OSI Clock Source Option for Other Modules OSC1 OSC2 Sleep HSPLL, INTOSC/PLL LP, XT, HS, RC, EC T1OSC CPU Peripherals IDLEN Postscaler MUX MUX 8 MHz 4 MHz 2 MHz 1 MHz 500 kHz 125 kHz 250 kHz OSCCON<6:4> 111 110 101 100 011 010 001 000 31 kHz INTRC Source Internal Oscillator Block WDT, PWRT, FSCM 8 MHz Internal Oscillator (INTOSC) OSCCON<6:4> Clock Control OSCCON<1:0> Source 8 MHz 31 kHz (INTRC) OSCTUNE<6> 0 1 OSCTUNE<7> and Two-Speed Start-up Primary Oscillator PIC18F2420/2520/4420/4520© 2008 Microchip Technology Inc. DS39631E-page 29 PIC18F2420/2520/4420/4520 2.7.1 OSCILLATOR CONTROL REGISTER The OSCCON register (Register 2-2) controls several aspects of the device clock’s operation, both in full-power operation and in power-managed modes. The System Clock Select bits, SCS<1:0>, select the clock source. The available clock sources are the primary clock (defined by the FOSC<3:0> Configuration bits), the secondary clock (Timer1 oscillator) and the internal oscillator block. The clock source changes immediately after one or more of the bits is written to, following a brief clock transition interval. The SCS bits are cleared on all forms of Reset. The Internal Oscillator Frequency Select bits (IRCF<2:0>) select the frequency output of the internal oscillator block to drive the device clock. The choices are the INTRC source, the INTOSC source (8 MHz) or one of the frequencies derived from the INTOSC postscaler (31.25 kHz to 4 MHz). If the internal oscillator block is supplying the device clock, changing the states of these bits will have an immediate change on the internal oscillator’s output. On device Resets, the default output frequency of the internal oscillator block is set at 1 MHz. When a nominal output frequency of 31 kHz is selected (IRCF<2:0> = 000), users may choose which internal oscillator acts as the source. This is done with the INTSRC bit in the OSCTUNE register (OSCTUNE<7>). Setting this bit selects INTOSC as a 31.25 kHz clock source by enabling the divide-by-256 output of the INTOSC postscaler. Clearing INTSRC selects INTRC (nominally 31 kHz) as the clock source. This option allows users to select the tunable and more precise INTOSC as a clock source, while maintaining power savings with a very low clock speed. Regardless of the setting of INTSRC, INTRC always remains the clock source for features such as the Watchdog Timer and the Fail-Safe Clock Monitor. The OSTS, IOFS and T1RUN bits indicate which clock source is currently providing the device clock. The OSTS bit indicates that the Oscillator Start-up Timer (OST) has timed out and the primary clock is providing the device clock in primary clock modes. The IOFS bit indicates when the internal oscillator block has stabilized and is providing the device clock in RC Clock modes. The T1RUN bit (T1CON<6>) indicates when the Timer1 oscillator is providing the device clock in secondary clock modes. In power-managed modes, only one of these three bits will be set at any time. If none of these bits are set, the INTRC is providing the clock or the internal oscillator block has just started and is not yet stable. The IDLEN bit determines if the device goes into Sleep mode or one of the Idle modes when the SLEEP instruction is executed. The use of the flag and control bits in the OSCCON register is discussed in more detail in Section 3.0 “Power-Managed Modes”. 2.7.2 OSCILLATOR TRANSITIONS PIC18F2420/2520/4420/4520 devices contain circuitry to prevent clock “glitches” when switching between clock sources. A short pause in the device clock occurs during the clock switch. The length of this pause is the sum of two cycles of the old clock source and three to four cycles of the new clock source. This formula assumes that the new clock source is stable. Clock transitions are discussed in greater detail in Section 3.1.2 “Entering Power-Managed Modes”. Note 1: The Timer1 oscillator must be enabled to select the secondary clock source. The Timer1 oscillator is enabled by setting the T1OSCEN bit in the Timer1 Control register (T1CON<3>). If the Timer1 oscillator is not enabled, then any attempt to select a secondary clock source will be ignored. 2: It is recommended that the Timer1 oscillator be operating and stable before selecting the secondary clock source or a very long delay may occur while the Timer1 oscillator starts. PIC18F2420/2520/4420/4520 DS39631E-page 30 © 2008 Microchip Technology Inc. REGISTER 2-2: OSCCON: OSCILLATOR CONTROL REGISTER R/W-0 R/W-1 R/W-0 R/W-0 R(1) R-0 R/W-0 R/W-0 IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 IDLEN: Idle Enable bit 1 = Device enters an Idle mode on SLEEP instruction 0 = Device enters Sleep mode on SLEEP instruction bit 6-4 IRCF<2:0>: Internal Oscillator Frequency Select bits 111 = 8 MHz (INTOSC drives clock directly) 110 = 4 MHz 101 = 2 MHz 100 = 1 MHz(3) 011 = 500 kHz 010 = 250 kHz 001 = 125 kHz 000 = 31 kHz (from either INTOSC/256 or INTRC directly)(2) bit 3 OSTS: Oscillator Start-up Timer Time-out Status bit(1) 1 = Oscillator Start-up Timer (OST) time-out has expired; primary oscillator is running 0 = Oscillator Start-up Timer (OST) time-out is running; primary oscillator is not ready bit 2 IOFS: INTOSC Frequency Stable bit 1 = INTOSC frequency is stable 0 = INTOSC frequency is not stable bit 1-0 SCS<1:0>: System Clock Select bits 1x = Internal oscillator block 01 = Secondary (Timer1) oscillator 00 = Primary oscillator Note 1: Reset state depends on state of the IESO Configuration bit. 2: Source selected by the INTSRC bit (OSCTUNE<7>), see text. 3: Default output frequency of INTOSC on Reset.© 2008 Microchip Technology Inc. DS39631E-page 31 PIC18F2420/2520/4420/4520 2.8 Effects of Power-Managed Modes on the Various Clock Sources When PRI_IDLE mode is selected, the designated primary oscillator continues to run without interruption. For all other power-managed modes, the oscillator using the OSC1 pin is disabled. The OSC1 pin (and OSC2 pin, if used by the oscillator) will stop oscillating. In secondary clock modes (SEC_RUN and SEC_IDLE), the Timer1 oscillator is operating and providing the device clock. The Timer1 oscillator may also run in all power-managed modes if required to clock Timer1 or Timer3. In internal oscillator modes (RC_RUN and RC_IDLE), the internal oscillator block provides the device clock source. The 31 kHz INTRC output can be used directly to provide the clock and may be enabled to support various special features, regardless of the powermanaged mode (see Section 23.2 “Watchdog Timer (WDT)”, Section 23.3 “Two-Speed Start-up” and Section 23.4 “Fail-Safe Clock Monitor” for more information on WDT, Fail-Safe Clock Monitor and TwoSpeed Start-up). The INTOSC output at 8 MHz may be used directly to clock the device or may be divided down by the postscaler. The INTOSC output is disabled if the clock is provided directly from the INTRC output. If Sleep mode is selected, all clock sources are stopped. Since all the transistor switching currents have been stopped, Sleep mode achieves the lowest current consumption of the device (only leakage currents). Enabling any on-chip feature that will operate during Sleep will increase the current consumed during Sleep. The INTRC is required to support WDT operation. The Timer1 oscillator may be operating to support a RealTime Clock. Other features may be operating that do not require a device clock source (i.e., MSSP slave, PSP, INTx pins and others). Peripherals that may add significant current consumption are listed in Section 26.2 “DC Characteristics”. 2.9 Power-up Delays Power-up delays are controlled by two timers so that no external Reset circuitry is required for most applications. The delays ensure that the device is kept in Reset until the device power supply is stable under normal circumstances and the primary clock is operating and stable. For additional information on power-up delays, see Section 4.5 “Device Reset Timers”. The first timer is the Power-up Timer (PWRT), which provides a fixed delay on power-up (parameter 33, Table 26-10). It is enabled by clearing (= 0) the PWRTEN Configuration bit. The second timer is the Oscillator Start-up Timer (OST), intended to keep the chip in Reset until the crystal oscillator is stable (LP, XT and HS modes). The OST does this by counting 1024 oscillator cycles before allowing the oscillator to clock the device. When the HSPLL Oscillator mode is selected, the device is kept in Reset for an additional 2 ms, following the HS mode OST delay, so the PLL can lock to the incoming clock frequency. There is a delay of interval, TCSD (parameter 38, Table 26-10), following POR, while the controller becomes ready to execute instructions. This delay runs concurrently with any other delays. This may be the only delay that occurs when any of the EC, RC or INTIO modes are used as the primary clock source. TABLE 2-3: OSC1 AND OSC2 PIN STATES IN SLEEP MODE OSC Mode OSC1 Pin OSC2 Pin RC, INTIO1 Floating, external resistor should pull high At logic low (clock/4 output) RCIO Floating, external resistor should pull high Configured as PORTA, bit 6 INTIO2 Configured as PORTA, bit 7 Configured as PORTA, bit 6 ECIO Floating, pulled by external clock Configured as PORTA, bit 6 EC Floating, pulled by external clock At logic low (clock/4 output) LP, XT and HS Feedback inverter disabled at quiescent voltage level Feedback inverter disabled at quiescent voltage level Note: See Table 4-2 in Section 4.0 “Reset” for time-outs due to Sleep and MCLR Reset.PIC18F2420/2520/4420/4520 DS39631E-page 32 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. Advance Information DS39631E-page 33 PIC18F2420/2520/4420/4520 3.0 POWER-MANAGED MODES PIC18F2420/2520/4420/4520 devices offer a total of seven operating modes for more efficient powermanagement. These modes provide a variety of options for selective power conservation in applications where resources may be limited (i.e., battery-powered devices). There are three categories of power-managed modes: • Run modes • Idle modes • Sleep mode These categories define which portions of the device are clocked and sometimes, what speed. The Run and Idle modes may use any of the three available clock sources (primary, secondary or internal oscillator block); the Sleep mode does not use a clock source. The power-managed modes include several powersaving features offered on previous PIC® devices. One is the clock switching feature, offered in other PIC18 devices, allowing the controller to use the Timer1 oscillator in place of the primary oscillator. Also included is the Sleep mode, offered by all PIC devices, where all device clocks are stopped. 3.1 Selecting Power-Managed Modes Selecting a power-managed mode requires two decisions: if the CPU is to be clocked or not and the selection of a clock source. The IDLEN bit (OSCCON<7>) controls CPU clocking, while the SCS<1:0> bits (OSCCON<1:0>) select the clock source. The individual modes, bit settings, clock sources and affected modules are summarized in Table 3-1. 3.1.1 CLOCK SOURCES The SCS<1:0> bits allow the selection of one of three clock sources for power-managed modes. They are: • the primary clock, as defined by the FOSC<3:0> Configuration bits • the secondary clock (the Timer1 oscillator) • the internal oscillator block (for RC modes) 3.1.2 ENTERING POWER-MANAGED MODES Switching from one power-managed mode to another begins by loading the OSCCON register. The SCS<1:0> bits select the clock source and determine which Run or Idle mode is to be used. Changing these bits causes an immediate switch to the new clock source, assuming that it is running. The switch may also be subject to clock transition delays. These are discussed in Section 3.1.3 “Clock Transitions and Status Indicators” and subsequent sections. Entry to the power-managed Idle or Sleep modes is triggered by the execution of a SLEEP instruction. The actual mode that results depends on the status of the IDLEN bit. Depending on the current mode and the mode being switched to, a change to a power-managed mode does not always require setting all of these bits. Many transitions may be done by changing the oscillator select bits, or changing the IDLEN bit, prior to issuing a SLEEP instruction. If the IDLEN bit is already configured correctly, it may only be necessary to perform a SLEEP instruction to switch to the desired mode. TABLE 3-1: POWER-MANAGED MODES Mode OSCCON<7,1:0> Bits Module Clocking Available Clock and Oscillator Source IDLEN(1) SCS<1:0> CPU Peripherals Sleep 0 N/A Off Off None – All clocks are disabled PRI_RUN N/A 00 Clocked Clocked Primary – LP, XT, HS, HSPLL, RC, EC and Internal Oscillator Block(2). This is the normal full-power execution mode. SEC_RUN N/A 01 Clocked Clocked Secondary – Timer1 Oscillator RC_RUN N/A 1x Clocked Clocked Internal Oscillator Block(2) PRI_IDLE 1 00 Off Clocked Primary – LP, XT, HS, HSPLL, RC, EC SEC_IDLE 1 01 Off Clocked Secondary – Timer1 Oscillator RC_IDLE 1 1x Off Clocked Internal Oscillator Block(2) Note 1: IDLEN reflects its value when the SLEEP instruction is executed. 2: Includes INTOSC and INTOSC postscaler, as well as the INTRC source.PIC18F2420/2520/4420/4520 DS39631E-page 34 Advance Information © 2008 Microchip Technology Inc. 3.1.3 CLOCK TRANSITIONS AND STATUS INDICATORS The length of the transition between clock sources is the sum of two cycles of the old clock source and three to four cycles of the new clock source. This formula assumes that the new clock source is stable. Three bits indicate the current clock source and its status. They are: • OSTS (OSCCON<3>) • IOFS (OSCCON<2>) • T1RUN (T1CON<6>) In general, only one of these bits will be set while in a given power-managed mode. When the OSTS bit is set, the primary clock is providing the device clock. When the IOFS bit is set, the INTOSC output is providing a stable 8 MHz clock source to a divider that actually drives the device clock. When the T1RUN bit is set, the Timer1 oscillator is providing the clock. If none of these bits are set, then either the INTRC clock source is clocking the device or the INTOSC source is not yet stable. If the internal oscillator block is configured as the primary clock source by the FOSC<3:0> Configuration bits, then both the OSTS and IOFS bits may be set when in PRI_RUN or PRI_IDLE modes. This indicates that the primary clock (INTOSC output) is generating a stable 8 MHz output. Entering another power-managed RC mode at the same frequency would clear the OSTS bit. 3.1.4 MULTIPLE SLEEP COMMANDS The power-managed mode that is invoked with the SLEEP instruction is determined by the setting of the IDLEN bit at the time the instruction is executed. If another SLEEP instruction is executed, the device will enter the power-managed mode specified by IDLEN at that time. If IDLEN has changed, the device will enter the new power-managed mode specified by the new setting. 3.2 Run Modes In the Run modes, clocks to both the core and peripherals are active. The difference between these modes is the clock source. 3.2.1 PRI_RUN MODE The PRI_RUN mode is the normal, full-power execution mode of the microcontroller. This is also the default mode upon a device Reset unless Two-Speed Start-up is enabled (see Section 23.3 “Two-Speed Start-up” for details). In this mode, the OSTS bit is set. The IOFS bit may be set if the internal oscillator block is the primary clock source (see Section 2.7.1 “Oscillator Control Register”). 3.2.2 SEC_RUN MODE The SEC_RUN mode is the compatible mode to the “clock switching” feature offered in other PIC18 devices. In this mode, the CPU and peripherals are clocked from the Timer1 oscillator. This gives users the option of lower power consumption while still using a high-accuracy clock source. SEC_RUN mode is entered by setting the SCS<1:0> bits to ‘01’. The device clock source is switched to the Timer1 oscillator (see Figure 3-1), the primary oscillator is shut down, the T1RUN bit (T1CON<6>) is set and the OSTS bit is cleared. On transitions from SEC_RUN mode to PRI_RUN mode, the peripherals and CPU continue to be clocked from the Timer1 oscillator while the primary clock is started. When the primary clock becomes ready, a clock switch back to the primary clock occurs (see Figure 3-2). When the clock switch is complete, the T1RUN bit is cleared, the OSTS bit is set and the primary clock is providing the clock. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run. Note 1: Caution should be used when modifying a single IRCF bit. If VDD is less than 3V, it is possible to select a higher clock speed than is supported by the low VDD. Improper device operation may result if the VDD/FOSC specifications are violated. 2: Executing a SLEEP instruction does not necessarily place the device into Sleep mode. It acts as the trigger to place the controller into either the Sleep mode or one of the Idle modes, depending on the setting of the IDLEN bit. Note: The Timer1 oscillator should already be running prior to entering SEC_RUN mode. If the T1OSCEN bit is not set when the SCS<1:0> bits are set to ‘01’, entry to SEC_RUN mode will not occur. If the Timer1 oscillator is enabled, but not yet running, device clocks will be delayed until the oscillator has started. In such situations, initial oscillator operation is far from stable and unpredictable operation may result.© 2008 Microchip Technology Inc. Advance Information DS39631E-page 35 PIC18F2420/2520/4420/4520 FIGURE 3-1: TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE FIGURE 3-2: TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL) 3.2.3 RC_RUN MODE In RC_RUN mode, the CPU and peripherals are clocked from the internal oscillator block using the INTOSC multiplexer. In this mode, the primary clock is shut down. When using the INTRC source, this mode provides the best power conservation of all the Run modes while still executing code. It works well for user applications which are not highly timing sensitive or do not require high-speed clocks at all times. If the primary clock source is the internal oscillator block (either INTRC or INTOSC), there are no distinguishable differences between PRI_RUN and RC_RUN modes during execution. However, a clock switch delay will occur during entry to and exit from RC_RUN mode. Therefore, if the primary clock source is the internal oscillator block, the use of RC_RUN mode is not recommended. This mode is entered by setting the SCS1 bit to ‘1’. Although it is ignored, it is recommended that the SCS0 bit also be cleared; this is to maintain software compatibility with future devices. When the clock source is switched to the INTOSC multiplexer (see Figure 3-3), the primary oscillator is shut down and the OSTS bit is cleared. The IRCF bits may be modified at any time to immediately change the clock speed. Q2 Q3 Q4 OSC1 Peripheral Program Q1 T1OSI Q1 Counter Clock CPU Clock PC PC + 2 1 2 3 n-1 n Clock Transition(1) Q2 Q3 Q4 Q1 Q2 Q3 PC + 4 Note 1: Clock transition typically occurs within 2-4 TOSC. Q1 Q3 Q4 OSC1 Peripheral Program PC T1OSI PLL Clock Q1 PC + 4 Q2 Output Q3 Q4 Q1 CPU Clock PC + 2 Clock Counter Q2 Q2 Q3 Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2: Clock transition typically occurs within 2-4 TOSC. SCS<1:0> bits Changed TPLL(1) 1 2 n-1 n Clock OSTS bit Set Transition(2) TOST(1) Note: Caution should be used when modifying a single IRCF bit. If VDD is less than 3V, it is possible to select a higher clock speed than is supported by the low VDD. Improper device operation may result if the VDD/FOSC specifications are violated.PIC18F2420/2520/4420/4520 DS39631E-page 36 Advance Information © 2008 Microchip Technology Inc. If the IRCF bits and the INTSRC bit are all clear, the INTOSC output is not enabled and the IOFS bit will remain clear; there will be no indication of the current clock source. The INTRC source is providing the device clocks. If the IRCF bits are changed from all clear (thus, enabling the INTOSC output), or if INTSRC is set, the IOFS bit becomes set after the INTOSC output becomes stable. Clocks to the device continue while the INTOSC source stabilizes after an interval of TIOBST. If the IRCF bits were previously at a non-zero value, or if INTSRC was set before setting SCS1 and the INTOSC source was already stable, the IOFS bit will remain set. On transitions from RC_RUN mode to PRI_RUN mode, the device continues to be clocked from the INTOSC multiplexer while the primary clock is started. When the primary clock becomes ready, a clock switch to the primary clock occurs (see Figure 3-4). When the clock switch is complete, the IOFS bit is cleared, the OSTS bit is set and the primary clock is providing the device clock. The IDLEN and SCS bits are not affected by the switch. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. FIGURE 3-3: TRANSITION TIMING TO RC_RUN MODE FIGURE 3-4: TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE Q2 Q3 Q4 OSC1 Peripheral Program Q1 INTRC Q1 Counter Clock CPU Clock PC PC + 2 1 2 3 n-1 n Clock Transition(1) Q2 Q3 Q4 Q1 Q2 Q3 PC + 4 Note 1: Clock transition typically occurs within 2-4 TOSC. Q1 Q3 Q4 OSC1 Peripheral Program PC INTOSC PLL Clock Q1 PC + 4 Q2 Output Q3 Q4 Q1 CPU Clock PC + 2 Clock Counter Q2 Q2 Q3 Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2: Clock transition typically occurs within 2-4 TOSC. SCS<1:0> bits Changed TPLL(1) 1 2 n-1 n Clock OSTS bit Set Transition(2) Multiplexer TOST(1)© 2008 Microchip Technology Inc. Advance Information DS39631E-page 37 PIC18F2420/2520/4420/4520 3.3 Sleep Mode The power-managed Sleep mode in the PIC18F2420/ 2520/4420/4520 devices is identical to the legacy Sleep mode offered in all other PIC devices. It is entered by clearing the IDLEN bit (the default state on device Reset) and executing the SLEEP instruction. This shuts down the selected oscillator (Figure 3-5). All clock source status bits are cleared. Entering the Sleep mode from any other mode does not require a clock switch. This is because no clocks are needed once the controller has entered Sleep. If the WDT is selected, the INTRC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. When a wake event occurs in Sleep mode (by interrupt, Reset or WDT time-out), the device will not be clocked until the clock source selected by the SCS<1:0> bits becomes ready (see Figure 3-6), or it will be clocked from the internal oscillator block if either the Two-Speed Start-up or the Fail-Safe Clock Monitor are enabled (see Section 23.0 “Special Features of the CPU”). In either case, the OSTS bit is set when the primary clock is providing the device clocks. The IDLEN and SCS bits are not affected by the wake-up. 3.4 Idle Modes The Idle modes allow the controller’s CPU to be selectively shut down while the peripherals continue to operate. Selecting a particular Idle mode allows users to further manage power consumption. If the IDLEN bit is set to ‘1’ when a SLEEP instruction is executed, the peripherals will be clocked from the clock source selected using the SCS<1:0> bits; however, the CPU will not be clocked. The clock source status bits are not affected. Setting IDLEN and executing a SLEEP instruction provides a quick method of switching from a given Run mode to its corresponding Idle mode. If the WDT is selected, the INTRC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. Since the CPU is not executing instructions, the only exits from any of the Idle modes are by interrupt, WDT time-out or a Reset. When a wake event occurs, CPU execution is delayed by an interval of TCSD (parameter 38, Table 26-10) while it becomes ready to execute code. When the CPU begins executing code, it resumes with the same clock source for the current Idle mode. For example, when waking from RC_IDLE mode, the internal oscillator block will clock the CPU and peripherals (in other words, RC_RUN mode). The IDLEN and SCS bits are not affected by the wake-up. While in any Idle mode or the Sleep mode, a WDT time-out will result in a WDT wake-up to the Run mode currently specified by the SCS1:SCS0 bits. FIGURE 3-5: TRANSITION TIMING FOR ENTRY TO SLEEP MODE FIGURE 3-6: TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL) Q2 Q3 Q4 OSC1 Peripheral Sleep Program Q1 Q1 Counter Clock CPU Clock PC PC + 2 Q3 Q4 Q1 Q2 OSC1 Peripheral Program PC PLL Clock Q3 Q4 Output CPU Clock Q1 Q2 Q3 Q4 Q1 Q2 Clock Counter PC + 4 PC + 6 Q1 Q2 Q3 Q4 Wake Event Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. TOST(1) TPLL(1) OSTS bit Set PC + 2PIC18F2420/2520/4420/4520 DS39631E-page 38 Advance Information © 2008 Microchip Technology Inc. 3.4.1 PRI_IDLE MODE This mode is unique among the three low-power Idle modes in that it does not disable the primary device clock. For timing-sensitive applications, this allows for the fastest resumption of device operation with its more accurate primary clock source, since the clock source does not have to “warm-up” or transition from another oscillator. PRI_IDLE mode is entered from PRI_RUN mode by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN first, then clear the SCS bits and execute SLEEP. Although the CPU is disabled, the peripherals continue to be clocked from the primary clock source specified by the FOSC<3:0> Configuration bits. The OSTS bit remains set (see Figure 3-7). When a wake event occurs, the CPU is clocked from the primary clock source. A delay of interval TCSD is required between the wake event and when code execution starts. This is required to allow the CPU to become ready to execute instructions. After the wakeup, the OSTS bit remains set. The IDLEN and SCS bits are not affected by the wake-up (see Figure 3-8). 3.4.2 SEC_IDLE MODE In SEC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the Timer1 oscillator. This mode is entered from SEC_RUN by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set the IDLEN bit first, then set the SCS<1:0> bits to ‘01’ and execute SLEEP. When the clock source is switched to the Timer1 oscillator, the primary oscillator is shut down, the OSTS bit is cleared and the T1RUN bit is set. When a wake event occurs, the peripherals continue to be clocked from the Timer1 oscillator. After an interval of TCSD, following the wake event, the CPU begins executing code being clocked by the Timer1 oscillator. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run (see Figure 3-8). FIGURE 3-7: TRANSITION TIMING FOR ENTRY TO IDLE MODE FIGURE 3-8: TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE Note: The Timer1 oscillator should already be running prior to entering SEC_IDLE mode. If the T1OSCEN bit is not set when the SLEEP instruction is executed, the SLEEP instruction will be ignored and entry to SEC_IDLE mode will not occur. If the Timer1 oscillator is enabled but not yet running, peripheral clocks will be delayed until the oscillator has started. In such situations, initial oscillator operation is far from stable and unpredictable operation may result. Q1 Peripheral Program PC PC + 2 OSC1 Q3 Q4 Q1 CPU Clock Clock Counter Q2 OSC1 Peripheral Program PC CPU Clock Q1 Q3 Q4 Clock Counter Q2 Wake Event TCSD© 2008 Microchip Technology Inc. Advance Information DS39631E-page 39 PIC18F2420/2520/4420/4520 3.4.3 RC_IDLE MODE In RC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the internal oscillator block using the INTOSC multiplexer. This mode allows for controllable power conservation during Idle periods. From RC_RUN, this mode is entered by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, first set IDLEN, then set the SCS1 bit and execute SLEEP. Although its value is ignored, it is recommended that SCS0 also be cleared; this is to maintain software compatibility with future devices. The INTOSC multiplexer may be used to select a higher clock frequency by modifying the IRCF bits before executing the SLEEP instruction. When the clock source is switched to the INTOSC multiplexer, the primary oscillator is shut down and the OSTS bit is cleared. If the IRCF bits are set to any non-zero value, or the INTSRC bit is set, the INTOSC output is enabled. The IOFS bit becomes set, after the INTOSC output becomes stable, after an interval of TIOBST (parameter 39, Table 26-10). Clocks to the peripherals continue while the INTOSC source stabilizes. If the IRCF bits were previously at a non-zero value, or INTSRC was set before the SLEEP instruction was executed and the INTOSC source was already stable, the IOFS bit will remain set. If the IRCF bits and INTSRC are all clear, the INTOSC output will not be enabled, the IOFS bit will remain clear and there will be no indication of the current clock source. When a wake event occurs, the peripherals continue to be clocked from the INTOSC multiplexer. After a delay of TCSD following the wake event, the CPU begins executing code being clocked by the INTOSC multiplexer. The IDLEN and SCS bits are not affected by the wake-up. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. 3.5 Exiting Idle and Sleep Modes An exit from Sleep mode or any of the Idle modes is triggered by an interrupt, a Reset or a WDT time-out. This section discusses the triggers that cause exits from power-managed modes. The clocking subsystem actions are discussed in each of the power-managed modes (see Section 3.2 “Run Modes”, Section 3.3 “Sleep Mode” and Section 3.4 “Idle Modes”). 3.5.1 EXIT BY INTERRUPT Any of the available interrupt sources can cause the device to exit from an Idle mode or the Sleep mode to a Run mode. To enable this functionality, an interrupt source must be enabled by setting its enable bit in one of the INTCON or PIE registers. The exit sequence is initiated when the corresponding interrupt flag bit is set. On all exits from Idle or Sleep modes by interrupt, code execution branches to the interrupt vector if the GIE/ GIEH bit (INTCON<7>) is set. Otherwise, code execution continues or resumes without branching (see Section 9.0 “Interrupts”). A fixed delay of interval TCSD following the wake event is required when leaving Sleep and Idle modes. This delay is required for the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. 3.5.2 EXIT BY WDT TIME-OUT A WDT time-out will cause different actions depending on which power-managed mode the device is in when the time-out occurs. If the device is not executing code (all Idle modes and Sleep mode), the time-out will result in an exit from the power-managed mode (see Section 3.2 “Run Modes” and Section 3.3 “Sleep Mode”). If the device is executing code (all Run modes), the time-out will result in a WDT Reset (see Section 23.2 “Watchdog Timer (WDT)”). The WDT timer and postscaler are cleared by executing a SLEEP or CLRWDT instruction, the loss of a currently selected clock source (if the Fail-Safe Clock Monitor is enabled) and modifying the IRCF bits in the OSCCON register if the internal oscillator block is the device clock source. 3.5.3 EXIT BY RESET Normally, the device is held in Reset by the Oscillator Start-up Timer (OST) until the primary clock becomes ready. At that time, the OSTS bit is set and the device begins executing code. If the internal oscillator block is the new clock source, the IOFS bit is set instead. The exit delay time from Reset to the start of code execution depends on both the clock sources before and after the wake-up and the type of oscillator if the new clock source is the primary clock. Exit delays are summarized in Table 3-2. Code execution can begin before the primary clock becomes ready. If either the Two-Speed Start-up (see Section 23.3 “Two-Speed Start-up”) or Fail-Safe Clock Monitor (see Section 23.4 “Fail-Safe Clock Monitor”) is enabled, the device may begin execution as soon as the Reset source has cleared. Execution is clocked by the INTOSC multiplexer driven by the internal oscillator block. Execution is clocked by the internal oscillator block until either the primary clock becomes ready or a power-managed mode is entered before the primary clock becomes ready; the primary clock is then shut down.PIC18F2420/2520/4420/4520 DS39631E-page 40 Advance Information © 2008 Microchip Technology Inc. 3.5.4 EXIT WITHOUT AN OSCILLATOR START-UP DELAY Certain exits from power-managed modes do not invoke the OST at all. There are two cases: • PRI_IDLE mode, where the primary clock source is not stopped and • the primary clock source is not any of the LP, XT, HS or HSPLL modes. In these instances, the primary clock source either does not require an oscillator start-up delay, since it is already running (PRI_IDLE), or normally does not require an oscillator start-up delay (RC, EC and INTIO Oscillator modes). However, a fixed delay of interval TCSD following the wake event is still required when leaving Sleep and Idle modes to allow the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. TABLE 3-2: EXIT DELAY ON WAKE-UP BY RESET FROM SLEEP MODE OR ANY IDLE MODE (BY CLOCK SOURCES) Clock Source Before Wake-up Clock Source After Wake-up Exit Delay Clock Ready Status Bit (OSCCON) Primary Device Clock (PRI_IDLE mode) LP, XT, HS TCSD HSPLL (1) OSTS EC, RC INTOSC(2) IOFS T1OSC or INTRC(1) LP, XT, HS TOST(3) HSPLL TOST + trc OSTS (3) EC, RC TCSD(1) INTOSC(2) TCSD(1) IOFS INTOSC(2) LP, XT, HS TOST(3) HSPLL TOST + trc OSTS (3) EC, RC TCSD(1) INTOSC(2) TCSD(1) IOFS None (Sleep mode) LP, XT, HS TOST(3) HSPLL TOST + trc OSTS (3) EC, RC TCSD(1) INTOSC(2) TCSD(1) IOFS Note 1: TCSD (parameter 38) is a required delay when waking from Sleep and all Idle modes and runs concurrently with any other required delays (see Section 3.4 “Idle Modes”). On Reset, INTOSC defaults to 1 MHz. 2: Includes both the INTOSC 8 MHz source and postscaler derived frequencies. 3: TOST is the Oscillator Start-up Timer (parameter 32). trc is the PLL lock-out timer (parameter F12); it is also designated as TPLL.© 2008 Microchip Technology Inc. DS39631E-page 41 PIC18F2420/2520/4420/4520 4.0 RESET The PIC18F2420/2520/4420/4520 devices differentiate between various kinds of Reset: a) Power-on Reset (POR) b) MCLR Reset during normal operation c) MCLR Reset during power-managed modes d) Watchdog Timer (WDT) Reset (during execution) e) Programmable Brown-out Reset (BOR) f) RESET Instruction g) Stack Full Reset h) Stack Underflow Reset This section discusses Resets generated by MCLR, POR and BOR and covers the operation of the various start-up timers. Stack Reset events are covered in Section 5.1.2.4 “Stack Full and Underflow Resets”. WDT Resets are covered in Section 23.2 “Watchdog Timer (WDT)”. A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 4-1. 4.1 RCON Register Device Reset events are tracked through the RCON register (Register 4-1). The lower five bits of the register indicate that a specific Reset event has occurred. In most cases, these bits can only be cleared by the event and must be set by the application after the event. The state of these flag bits, taken together, can be read to indicate the type of Reset that just occurred. This is described in more detail in Section 4.6 “Reset State of Registers”. The RCON register also has control bits for setting interrupt priority (IPEN) and software control of the BOR (SBOREN). Interrupt priority is discussed in Section 9.0 “Interrupts”. BOR is covered in Section 4.4 “Brown-out Reset (BOR)”. FIGURE 4-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT External Reset MCLR VDD OSC1 WDT Time-out VDD Rise Detect OST/PWRT INTRC(1) POR Pulse OST 10-Bit Ripple Counter PWRT 11-Bit Ripple Counter Enable OST(2) Enable PWRT Note 1: This is the INTRC source from the internal oscillator block and is separate from the RC oscillator of the CLKI pin. 2: See Table 4-2 for time-out situations. Brown-out Reset BOREN RESET Instruction Stack Pointer Stack Full/Underflow Reset Sleep ( )_IDLE 1024 Cycles 65.5 ms 32 μs MCLRE S R Q Chip_ResetPIC18F2420/2520/4420/4520 DS39631E-page 42 © 2008 Microchip Technology Inc. REGISTER 4-1: RCON: RESET CONTROL REGISTER R/W-0 R/W-1(1) U-0 R/W-1 R-1 R-1 R/W-0(2) R/W-0 IPEN SBOREN — RI TO PD POR BOR bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) bit 6 SBOREN: BOR Software Enable bit(1) If BOREN1:BOREN0 = 01: 1 = BOR is enabled 0 = BOR is disabled If BOREN1:BOREN0 = 00, 10 or 11: Bit is disabled and read as ‘0’. bit 5 Unimplemented: Read as ‘0’ bit 4 RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed (set by firmware only) 0 = The RESET instruction was executed causing a device Reset (must be set in software after a Brown-out Reset occurs) bit 3 TO: Watchdog Time-out Flag bit 1 = Set by power-up, CLRWDT instruction or SLEEP instruction 0 = A WDT time-out occurred bit 2 PD: Power-Down Detection Flag bit 1 = Set by power-up or by the CLRWDT instruction 0 = Set by execution of the SLEEP instruction bit 1 POR: Power-on Reset Status bit 1 = A Power-on Reset has not occurred (set by firmware only) 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) bit 0 BOR: Brown-out Reset Status bit 1 = A Brown-out Reset has not occurred (set by firmware only) 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) Note 1: If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’. 2: The actual Reset value of POR is determined by the type of device Reset. See the notes following this register and Section 4.6 “Reset State of Registers” for additional information. Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected so that subsequent Power-on Resets may be detected. 2: Brown-out Reset is said to have occurred when BOR is ‘0’ and POR is ‘1’ (assuming that POR was set to ‘1’ by software immediately after a Power-on Reset).© 2008 Microchip Technology Inc. DS39631E-page 43 PIC18F2420/2520/4420/4520 4.2 Master Clear (MCLR) The MCLR pin provides a method for triggering an external Reset of the device. A Reset is generated by holding the pin low. These devices have a noise filter in the MCLR Reset path which detects and ignores small pulses. The MCLR pin is not driven low by any internal Resets, including the WDT. In PIC18F2420/2520/4420/4520 devices, the MCLR input can be disabled with the MCLRE Configuration bit. When MCLR is disabled, the pin becomes a digital input. See Section 10.5 “PORTE, TRISE and LATE Registers” for more information. 4.3 Power-on Reset (POR) A Power-on Reset pulse is generated on-chip whenever VDD rises above a certain threshold. This allows the device to start in the initialized state when VDD is adequate for operation. To take advantage of the POR circuitry, tie the MCLR pin through a resistor (1 kΩ to 10 kΩ) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. A minimum rise rate for VDD is specified (parameter D004). For a slow rise time, see Figure 4-2. When the device starts normal operation (i.e., exits the Reset condition), device operating parameters (voltage, frequency, temperature, etc.) must be met to ensure operation. If these conditions are not met, the device must be held in Reset until the operating conditions are met. POR events are captured by the POR bit (RCON<1>). The state of the bit is set to ‘0’ whenever a POR occurs; it does not change for any other Reset event. POR is not reset to ‘1’ by any hardware event. To capture multiple events, the user manually resets the bit to ‘1’ in software following any POR. FIGURE 4-2: EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) Note 1: External Power-on Reset circuit is required only if the VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 kΩ is recommended to make sure that the voltage drop across R does not violate the device’s electrical specification. 3: R1 ≥ 1 kΩ will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown, due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). C R1 D R VDD MCLR PIC18FXXXX VDDPIC18F2420/2520/4420/4520 DS39631E-page 44 © 2008 Microchip Technology Inc. 4.4 Brown-out Reset (BOR) PIC18F2420/2520/4420/4520 devices implement a BOR circuit that provides the user with a number of configuration and power-saving options. The BOR is controlled by the BORV<1:0> and BOREN<1:0> Configuration bits. There are a total of four BOR configurations which are summarized in Table 4-1. The BOR threshold is set by the BORV<1:0> bits. If BOR is enabled (any values of BOREN<1:0>, except ‘00’), any drop of VDD below VBOR (parameter D005) for greater than TBOR (parameter 35) will reset the device. A Reset may or may not occur if VDD falls below VBOR for less than TBOR. The chip will remain in Brown-out Reset until VDD rises above VBOR. If the Power-up Timer is enabled, it will be invoked after VDD rises above VBOR; it then will keep the chip in Reset for an additional time delay, TPWRT (parameter 33). If VDD drops below VBOR while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above VBOR, the Power-up Timer will execute the additional time delay. BOR and the Power-up Timer (PWRT) are independently configured. Enabling the Brown-out Reset does not automatically enable the PWRT. 4.4.1 SOFTWARE ENABLED BOR When BOREN<1:0> = 01, the BOR can be enabled or disabled by the user in software. This is done with the control bit, SBOREN (RCON<6>). Setting SBOREN enables the BOR to function as previously described. Clearing SBOREN disables the BOR entirely. The SBOREN bit operates only in this mode; otherwise it is read as ‘0’. Placing the BOR under software control gives the user the additional flexibility of tailoring the application to its environment without having to reprogram the device to change BOR configuration. It also allows the user to tailor device power consumption in software by eliminating the incremental current that the BOR consumes. While the BOR current is typically very small, it may have some impact in low-power applications. 4.4.2 DETECTING BOR When BOR is enabled, the BOR bit always resets to ‘0’ on any BOR or POR event. This makes it difficult to determine if a BOR event has occurred just by reading the state of BOR alone. A more reliable method is to simultaneously check the state of both POR and BOR. This assumes that the POR bit is reset to ‘1’ in software immediately after any POR event. If BOR is ‘0’ while POR is ‘1’, it can be reliably assumed that a BOR event has occurred. 4.4.3 DISABLING BOR IN SLEEP MODE When BOREN<1:0> = 10, the BOR remains under hardware control and operates as previously described. Whenever the device enters Sleep mode, however, the BOR is automatically disabled. When the device returns to any other operating mode, BOR is automatically re-enabled. This mode allows for applications to recover from brown-out situations, while actively executing code, when the device requires BOR protection the most. At the same time, it saves additional power in Sleep mode by eliminating the small incremental BOR current. TABLE 4-1: BOR CONFIGURATIONS Note: Even when BOR is under software control, the Brown-out Reset voltage level is still set by the BORV<1:0> Configuration bits; it cannot be changed in software. BOR Configuration Status of SBOREN (RCON<6>) BOR Operation BOREN1 BOREN0 0 0 Unavailable BOR disabled; must be enabled by reprogramming the Configuration bits. 0 1 Available BOR enabled in software; operation controlled by SBOREN. 1 0 Unavailable BOR enabled in hardware in Run and Idle modes, disabled during Sleep mode. 1 1 Unavailable BOR enabled in hardware; must be disabled by reprogramming the Configuration bits.© 2008 Microchip Technology Inc. DS39631E-page 45 PIC18F2420/2520/4420/4520 4.5 Device Reset Timers PIC18F2420/2520/4420/4520 devices incorporate three separate on-chip timers that help regulate the Power-on Reset process. Their main function is to ensure that the device clock is stable before code is executed. These timers are: • Power-up Timer (PWRT) • Oscillator Start-up Timer (OST) • PLL Lock Time-out 4.5.1 POWER-UP TIMER (PWRT) The Power-up Timer (PWRT) of PIC18F2420/2520/ 4420/4520 devices is an 11-bit counter which uses the INTRC source as the clock input. This yields an approximate time interval of 2048 x 32 μs = 65.6 ms. While the PWRT is counting, the device is held in Reset. The power-up time delay depends on the INTRC clock and will vary from chip to chip due to temperature and process variation. See DC parameter 33 for details. The PWRT is enabled by clearing the PWRTEN Configuration bit. 4.5.2 OSCILLATOR START-UP TIMER (OST) The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over (parameter 33). This ensures that the crystal oscillator or resonator has started and stabilized. The OST time-out is invoked only for XT, LP, HS and HSPLL modes and only on Power-on Reset, or on exit from most power-managed modes. 4.5.3 PLL LOCK TIME-OUT With the PLL enabled in its PLL mode, the time-out sequence following a Power-on Reset is slightly different from other oscillator modes. A separate timer is used to provide a fixed time-out that is sufficient for the PLL to lock to the main oscillator frequency. This PLL lock time-out (TPLL) is typically 2 ms and follows the oscillator start-up time-out. 4.5.4 TIME-OUT SEQUENCE On power-up, the time-out sequence is as follows: 1. After the POR pulse has cleared, PWRT time-out is invoked (if enabled). 2. Then, the OST is activated. The total time-out will vary based on oscillator configuration and the status of the PWRT. Figure 4-3, Figure 4-4, Figure 4-5, Figure 4-6 and Figure 4-7 all depict time-out sequences on power-up, with the Power-up Timer enabled and the device operating in HS Oscillator mode. Figure 4-3 through Figure 4-6 also apply to devices operating in XT or LP modes. For devices in RC mode and with the PWRT disabled, on the other hand, there will be no time-out at all. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, all time-outs will expire. Bringing MCLR high will begin execution immediately (Figure 4-5). This is useful for testing purposes or to synchronize more than one PIC18FXXXX device operating in parallel. TABLE 4-2: TIME-OUT IN VARIOUS SITUATIONS Oscillator Configuration Power-up(2) and Brown-out Exit from Power-Managed Mode PWRTEN = 0 PWRTEN = 1 HSPLL 66 ms(1) + 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2) HS, XT, LP 66 ms(1) + 1024 TOSC 1024 TOSC 1024 TOSC EC, ECIO 66 ms(1) — — RC, RCIO 66 ms(1) — — INTIO1, INTIO2 66 ms(1) — — Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay. 2: 2 ms is the nominal time required for the PLL to lock.PIC18F2420/2520/4420/4520 DS39631E-page 46 © 2008 Microchip Technology Inc. FIGURE 4-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT) FIGURE 4-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 FIGURE 4-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TPWRT TOST© 2008 Microchip Technology Inc. DS39631E-page 47 PIC18F2420/2520/4420/4520 FIGURE 4-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT) FIGURE 4-7: TIME-OUT SEQUENCE ON POR W/PLL ENABLED (MCLR TIED TO VDD) VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET 0V 5V TPWRT TOST TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET PLL TIME-OUT TPLL Note: TOST = 1024 clock cycles. TPLL ≈ 2 ms max. First three stages of the PWRT timer.PIC18F2420/2520/4420/4520 DS39631E-page 48 © 2008 Microchip Technology Inc. 4.6 Reset State of Registers Most registers are unaffected by a Reset. Their status is unknown on POR and unchanged by all other Resets. The other registers are forced to a “Reset state” depending on the type of Reset that occurred. Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. Status bits from the RCON register, RI, TO, PD, POR and BOR, are set or cleared differently in different Reset situations, as indicated in Table 4-3. These bits are used in software to determine the nature of the Reset. Table 4-4 describes the Reset states for all of the Special Function Registers. These are categorized by Power-on and Brown-out Resets, Master Clear and WDT Resets and WDT wake-ups. TABLE 4-3: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER Condition Program Counter RCON Register STKPTR Register RI TO PD POR BOR STKFUL STKUNF Power-on Reset 0000h 11100 0 0 RESET Instruction 0000h 0uuuu u u Brown-out Reset 0000h 111u0 u u MCLR Reset during Power-Managed Run Modes 0000h u1uuu u u MCLR Reset during Power-Managed Idle Modes and Sleep Mode 0000h u10uu u u WDT Time-out during Full Power or Power-Managed Run Mode 0000h u0uuu u u MCLR Reset during Full-Power Execution 0000h uuuuu u u Stack Full Reset (STVREN = 1) 0000h uuuuu 1 u Stack Underflow Reset (STVREN = 1) 0000h uuuuu u 1 Stack Underflow Error (not an actual Reset, STVREN = 0) 0000h uuuuu u 1 WDT Time-out during Power-Managed Idle or Sleep Modes PC + 2 u00uu u u Interrupt Exit from Power-Managed Modes PC + 2(1) uu0uu u u Legend: u = unchanged Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the interrupt vector (008h or 0018h).© 2008 Microchip Technology Inc. DS39631E-page 49 PIC18F2420/2520/4420/4520 TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt TOSU 2420 2520 4420 4520 ---0 0000 ---0 0000 ---0 uuuu(3) TOSH 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu(3) TOSL 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu(3) STKPTR 2420 2520 4420 4520 00-0 0000 uu-0 0000 uu-u uuuu(3) PCLATU 2420 2520 4420 4520 ---0 0000 ---0 0000 ---u uuuu PCLATH 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu PCL 2420 2520 4420 4520 0000 0000 0000 0000 PC + 2(2) TBLPTRU 2420 2520 4420 4520 --00 0000 --00 0000 --uu uuuu TBLPTRH 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu TBLPTRL 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu TABLAT 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu PRODH 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu PRODL 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu INTCON 2420 2520 4420 4520 0000 000x 0000 000u uuuu uuuu(1) INTCON2 2420 2520 4420 4520 1111 -1-1 1111 -1-1 uuuu -u-u(1) INTCON3 2420 2520 4420 4520 11-0 0-00 11-0 0-00 uu-u u-uu(1) INDF0 2420 2520 4420 4520 N/A N/A N/A POSTINC0 2420 2520 4420 4520 N/A N/A N/A POSTDEC0 2420 2520 4420 4520 N/A N/A N/A PREINC0 2420 2520 4420 4520 N/A N/A N/A PLUSW0 2420 2520 4420 4520 N/A N/A N/A FSR0H 2420 2520 4420 4520 ---- 0000 ---- 0000 ---- uuuu FSR0L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu WREG 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu INDF1 2420 2520 4420 4520 N/A N/A N/A POSTINC1 2420 2520 4420 4520 N/A N/A N/A POSTDEC1 2420 2520 4420 4520 N/A N/A N/A PREINC1 2420 2520 4420 4520 N/A N/A N/A PLUSW1 2420 2520 4420 4520 N/A N/A N/A Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: The Reset value of the PCFG bits depends on the value of the PBADEN Configuration bit (CONFIG3H<1>). When PBADEN = 1, PCFG<2:0> = 000; when PBADEN = 0, PCFG<2:0> = 111.PIC18F2420/2520/4420/4520 DS39631E-page 50 © 2008 Microchip Technology Inc. FSR1H 2420 2520 4420 4520 ---- 0000 ---- 0000 ---- uuuu FSR1L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu BSR 2420 2520 4420 4520 ---- 0000 ---- 0000 ---- uuuu INDF2 2420 2520 4420 4520 N/A N/A N/A POSTINC2 2420 2520 4420 4520 N/A N/A N/A POSTDEC2 2420 2520 4420 4520 N/A N/A N/A PREINC2 2420 2520 4420 4520 N/A N/A N/A PLUSW2 2420 2520 4420 4520 N/A N/A N/A FSR2H 2420 2520 4420 4520 ---- 0000 ---- 0000 ---- uuuu FSR2L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu STATUS 2420 2520 4420 4520 ---x xxxx ---u uuuu ---u uuuu TMR0H 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu TMR0L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu T0CON 2420 2520 4420 4520 1111 1111 1111 1111 uuuu uuuu OSCCON 2420 2520 4420 4520 0100 q000 0100 q000 uuuu quuu HLVDCON 2420 2520 4420 4520 0-00 0101 0-00 0101 u-uu uuuu WDTCON 2420 2520 4420 4520 ---- ---0 ---- ---0 ---- ---u RCON(4) 2420 2520 4420 4520 0q-1 11q0 0q-q qquu uq-u qquu TMR1H 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu TMR1L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu T1CON 2420 2520 4420 4520 0000 0000 u0uu uuuu uuuu uuuu TMR2 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu PR2 2420 2520 4420 4520 1111 1111 1111 1111 1111 1111 T2CON 2420 2520 4420 4520 -000 0000 -000 0000 -uuu uuuu SSPBUF 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu SSPADD 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu SSPSTAT 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu SSPCON1 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu SSPCON2 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: The Reset value of the PCFG bits depends on the value of the PBADEN Configuration bit (CONFIG3H<1>). When PBADEN = 1, PCFG<2:0> = 000; when PBADEN = 0, PCFG<2:0> = 111.© 2008 Microchip Technology Inc. DS39631E-page 51 PIC18F2420/2520/4420/4520 ADRESH 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu ADRESL 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu ADCON0 2420 2520 4420 4520 --00 0000 --00 0000 --uu uuuu ADCON1 2420 2520 4420 4520 --00 0qqq(6) --00 0qqq(6) --uu uuuu ADCON2 2420 2520 4420 4520 0-00 0000 0-00 0000 u-uu uuuu CCPR1H 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu CCPR1L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu CCP1CON 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu 2420 2520 4420 4520 --00 0000 --00 0000 --uu uuuu CCPR2H 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu CCPR2L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu CCP2CON 2420 2520 4420 4520 --00 0000 --00 0000 --uu uuuu BAUDCON 2420 2520 4420 4520 0100 0-00 0100 0-00 uuuu u-uu PWM1CON 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu ECCP1AS 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu 2420 2520 4420 4520 0000 00-- 0000 00-- uuuu uu-- CVRCON 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu CMCON 2420 2520 4420 4520 0000 0111 0000 0111 uuuu uuuu TMR3H 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu TMR3L 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu T3CON 2420 2520 4420 4520 0000 0000 uuuu uuuu uuuu uuuu SPBRGH 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu SPBRG 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu RCREG 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu TXREG 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu TXSTA 2420 2520 4420 4520 0000 0010 0000 0010 uuuu uuuu RCSTA 2420 2520 4420 4520 0000 000x 0000 000x uuuu uuuu EEADR 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu EEDATA 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu EECON2 2420 2520 4420 4520 0000 0000 0000 0000 0000 0000 EECON1 2420 2520 4420 4520 xx-0 x000 uu-0 u000 uu-0 u000 TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: The Reset value of the PCFG bits depends on the value of the PBADEN Configuration bit (CONFIG3H<1>). When PBADEN = 1, PCFG<2:0> = 000; when PBADEN = 0, PCFG<2:0> = 111.PIC18F2420/2520/4420/4520 DS39631E-page 52 © 2008 Microchip Technology Inc. IPR2 2420 2520 4420 4520 11-1 1111 11-1 1111 uu-u uuuu PIR2 2420 2520 4420 4520 00-0 0000 00-0 0000 uu-u uuuu(1) PIE2 2420 2520 4420 4520 00-0 0000 00-0 0000 uu-u uuuu IPR1 2420 2520 4420 4520 1111 1111 1111 1111 uuuu uuuu 2420 2520 4420 4520 -111 1111 -111 1111 -uuu uuuu PIR1 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu(1) 2420 2520 4420 4520 -000 0000 -000 0000 -uuu uuuu(1) PIE1 2420 2520 4420 4520 0000 0000 0000 0000 uuuu uuuu 2420 2520 4420 4520 -000 0000 -000 0000 -uuu uuuu OSCTUNE 2420 2520 4420 4520 00-0 0000 00-0 0000 uu-u uuuu TRISE 2420 2520 4420 4520 0000 -111 0000 -111 uuuu -uuu TRISD 2420 2520 4420 4520 1111 1111 1111 1111 uuuu uuuu TRISC 2420 2520 4420 4520 1111 1111 1111 1111 uuuu uuuu TRISB 2420 2520 4420 4520 1111 1111 1111 1111 uuuu uuuu TRISA(5) 2420 2520 4420 4520 1111 1111(5) 1111 1111(5) uuuu uuuu(5) LATE 2420 2520 4420 4520 ---- -xxx ---- -uuu ---- -uuu LATD 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu LATC 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu LATB 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu LATA(5) 2420 2520 4420 4520 xxxx xxxx(5) uuuu uuuu(5) uuuu uuuu(5) PORTE 2420 2520 4420 4520 ---- xxxx ---- uuuu ---- uuuu PORTD 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu PORTC 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu PORTB 2420 2520 4420 4520 xxxx xxxx uuuu uuuu uuuu uuuu PORTA(5) 2420 2520 4420 4520 xx0x 0000(5) uu0u 0000(5) uuuu uuuu(5) TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read ‘0’. 6: The Reset value of the PCFG bits depends on the value of the PBADEN Configuration bit (CONFIG3H<1>). When PBADEN = 1, PCFG<2:0> = 000; when PBADEN = 0, PCFG<2:0> = 111.© 2008 Microchip Technology Inc. DS39631E-page 53 PIC18F2420/2520/4420/4520 5.0 MEMORY ORGANIZATION There are three types of memory in PIC18 enhanced microcontroller devices: • Program Memory • Data RAM • Data EEPROM As Harvard architecture devices, the data and program memories use separate busses; this allows for concurrent access of the two memory spaces. The data EEPROM, for practical purposes, can be regarded as a peripheral device, since it is addressed and accessed through a set of control registers. Additional detailed information on the operation of the Flash program memory is provided in Section 6.0 “Flash Program Memory”. Data EEPROM is discussed separately in Section 7.0 “Data EEPROM Memory”. 5.1 Program Memory Organization PIC18 microcontrollers implement a 21-bit program counter, which is capable of addressing a 2-Mbyte program memory space. Accessing a location between the upper boundary of the physically implemented memory and the 2-Mbyte address will return all ‘0’s (a NOP instruction). The PIC18F2420 and PIC18F4420 each have 16 Kbytes of Flash memory and can store up to 8,192 single-word instructions. The PIC18F2520 and PIC18F4520 each have 32 Kbytes of Flash memory and can store up to 16,384 single-word instructions. PIC18 devices have two interrupt vectors. The Reset vector address is at 0000h and the interrupt vector addresses are at 0008h and 0018h. The program memory map for PIC18F2420/2520/ 4420/4520 devices is shown in Figure 5-1. FIGURE 5-1: PROGRAM MEMORY MAP AND STACK FOR PIC18F2420/2520/4420/4520 DEVICES PC<20:0> Stack Level 1 • Stack Level 31 Reset Vector Low-Priority Interrupt Vector • • CALL,RCALL,RETURN RETFIE,RETLW 21 0000h 0018h On-Chip Program Memory High-Priority Interrupt Vector 0008h User Memory Space 1FFFFFh 4000h 3FFFh Read ‘0’ 200000h 8000h 7FFFh On-Chip Program Memory Read ‘0’ PIC18F2420/4420 PIC18F2520/4520PIC18F2420/2520/4420/4520 DS39631E-page 54 © 2008 Microchip Technology Inc. 5.1.1 PROGRAM COUNTER The Program Counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21 bits wide and is contained in three separate 8-bit registers. The low byte, known as the PCL register, is both readable and writable. The high byte, or PCH register, contains the PC<15:8> bits; it is not directly readable or writable. Updates to the PCH register are performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits; it is also not directly readable or writable. Updates to the PCU register are performed through the PCLATU register. The contents of PCLATH and PCLATU are transferred to the program counter by any operation that writes PCL. Similarly, the upper two bytes of the program counter are transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 5.1.4.1 “Computed GOTO”). The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the Least Significant bit of PCL is fixed to a value of ‘0’. The PC increments by 2 to address sequential instructions in the program memory. The CALL, RCALL, GOTO and program branch instructions write to the program counter directly. For these instructions, the contents of PCLATH and PCLATU are not transferred to the program counter. 5.1.2 RETURN ADDRESS STACK The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC is pushed onto the stack when a CALL or RCALL instruction is executed or an interrupt is Acknowledged. The PC value is pulled off the stack on a RETURN, RETLW or a RETFIE instruction. PCLATU and PCLATH are not affected by any of the RETURN or CALL instructions. The stack operates as a 31-word by 21-bit RAM and a 5-bit Stack Pointer, STKPTR. The stack space is not part of either program or data space. The Stack Pointer is readable and writable and the address on the top of the stack is readable and writable through the Top-ofStack (TOS) Special Function Registers. Data can also be pushed to, or popped from the stack, using these registers. A CALL type instruction causes a push onto the stack; the Stack Pointer is first incremented and the location pointed to by the Stack Pointer is written with the contents of the PC (already pointing to the instruction following the CALL). A RETURN type instruction causes a pop from the stack; the contents of the location pointed to by the STKPTR are transferred to the PC and then the Stack Pointer is decremented. The Stack Pointer is initialized to ‘00000’ after all Resets. There is no RAM associated with the location corresponding to a Stack Pointer value of ‘00000’; this is only a Reset value. Status bits indicate if the stack is full, or has overflowed or underflowed. 5.1.2.1 Top-of-Stack Access Only the top of the return address stack (TOS) is readable and writable. A set of three registers, TOSU:TOSH:TOSL, hold the contents of the stack location pointed to by the STKPTR register (Figure 5-2). This allows users to implement a software stack if necessary. After a CALL, RCALL or interrupt, the software can read the pushed value by reading the TOSU:TOSH:TOSL registers. These values can be placed on a user-defined software stack. At return time, the software can return these values to TOSU:TOSH:TOSL and do a return. The user must disable the global interrupt enable bits while accessing the stack to prevent inadvertent stack corruption. FIGURE 5-2: RETURN ADDRESS STACK AND ASSOCIATED REGISTERS 00011 001A34h 11111 11110 11101 00010 00001 00000 00010 Return Address Stack <20:0> Top-of-Stack 000D58h TOSU TOSH TOSL 00h 1Ah 34h STKPTR<4:0> Top-of-Stack Registers Stack Pointer© 2008 Microchip Technology Inc. DS39631E-page 55 PIC18F2420/2520/4420/4520 5.1.2.2 Return Stack Pointer (STKPTR) The STKPTR register (Register 5-1) contains the Stack Pointer value, the STKFUL (Stack Full) status bit and the STKUNF (Stack Underflow) status bits. The value of the Stack Pointer can be 0 through 31. The Stack Pointer increments before values are pushed onto the stack and decrements after values are popped off the stack. On Reset, the Stack Pointer value will be zero. The user may read and write the Stack Pointer value. This feature can be used by a Real-Time Operating System (RTOS) for return stack maintenance. After the PC is pushed onto the stack 31 times (without popping any values off the stack), the STKFUL bit is set. The STKFUL bit is cleared by software or by a POR. The action that takes place when the stack becomes full depends on the state of the STVREN (Stack Overflow Reset Enable) Configuration bit. (Refer to Section 23.1 “Configuration Bits” for a description of the device Configuration bits.) If STVREN is set (default), the 31st push will push the (PC + 2) value onto the stack, set the STKFUL bit and reset the device. The STKFUL bit will remain set and the Stack Pointer will be set to zero. If STVREN is cleared, the STKFUL bit will be set on the 31st push and the Stack Pointer will increment to 31. Any additional pushes will not overwrite the 31st push and STKPTR will remain at 31. When the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the PC and sets the STKUNF bit, while the Stack Pointer remains at zero. The STKUNF bit will remain set until cleared by software or until a POR occurs. 5.1.2.3 PUSH and POP Instructions Since the Top-of-Stack is readable and writable, the ability to push values onto the stack and pull values off the stack without disturbing normal program execution is a desirable feature. The PIC18 instruction set includes two instructions, PUSH and POP, that permit the TOS to be manipulated under software control. TOSU, TOSH and TOSL can be modified to place data or a return address on the stack. The PUSH instruction places the current PC value onto the stack. This increments the Stack Pointer and loads the current PC value onto the stack. The POP instruction discards the current TOS by decrementing the Stack Pointer. The previous value pushed onto the stack then becomes the TOS value. Note: Returning a value of zero to the PC on an underflow has the effect of vectoring the program to the Reset vector, where the stack conditions can be verified and appropriate actions can be taken. This is not the same as a Reset, as the contents of the SFRs are not affected. REGISTER 5-1: STKPTR: STACK POINTER REGISTER R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 STKFUL(1) STKUNF(1) — SP4 SP3 SP2 SP1 SP0 bit 7 bit 0 Legend: C = Clearable bit R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 STKFUL: Stack Full Flag bit(1) 1 = Stack became full or overflowed 0 = Stack has not become full or overflowed bit 6 STKUNF: Stack Underflow Flag bit(1) 1 = Stack underflow occurred 0 = Stack underflow did not occur bit 5 Unimplemented: Read as ‘0’ bit 4-0 SP<4:0>: Stack Pointer Location bits Note 1: Bit 7 and bit 6 are cleared by user software or by a POR.PIC18F2420/2520/4420/4520 DS39631E-page 56 © 2008 Microchip Technology Inc. 5.1.2.4 Stack Full and Underflow Resets Device Resets on stack overflow and stack underflow conditions are enabled by setting the STVREN bit in Configuration Register 4L. When STVREN is set, a full or underflow will set the appropriate STKFUL or STKUNF bit and then cause a device Reset. When STVREN is cleared, a full or underflow condition will set the appropriate STKFUL or STKUNF bit but not cause a device Reset. The STKFUL or STKUNF bits are cleared by the user software or a Power-on Reset. 5.1.3 FAST REGISTER STACK A Fast Register Stack is provided for the STATUS, WREG and BSR registers, to provide a “fast return” option for interrupts. The stack for each register is only one level deep and is neither readable nor writable. It is loaded with the current value of the corresponding register when the processor vectors for an interrupt. All interrupt sources will push values into the stack registers. The values in the registers are then loaded back into their associated registers if the RETFIE, FAST instruction is used to return from the interrupt. If both low and high-priority interrupts are enabled, the stack registers cannot be used reliably to return from low-priority interrupts. If a high-priority interrupt occurs while servicing a low-priority interrupt, the stack register values stored by the low-priority interrupt will be overwritten. In these cases, users must save the key registers in software during a low-priority interrupt. If interrupt priority is not used, all interrupts may use the Fast Register Stack for returns from interrupt. If no interrupts are used, the Fast Register Stack can be used to restore the STATUS, WREG and BSR registers at the end of a subroutine call. To use the Fast Register Stack for a subroutine call, a CALL label, FAST instruction must be executed to save the STATUS, WREG and BSR registers to the Fast Register Stack. A RETURN, FAST instruction is then executed to restore these registers from the Fast Register Stack. Example 5-1 shows a source code example that uses the Fast Register Stack during a subroutine call and return. EXAMPLE 5-1: FAST REGISTER STACK CODE EXAMPLE 5.1.4 LOOK-UP TABLES IN PROGRAM MEMORY There may be programming situations that require the creation of data structures, or look-up tables, in program memory. For PIC18 devices, look-up tables can be implemented in two ways: • Computed GOTO • Table Reads 5.1.4.1 Computed GOTO A computed GOTO is accomplished by adding an offset to the program counter. An example is shown in Example 5-2. A look-up table can be formed with an ADDWF PCL instruction and a group of RETLW nn instructions. The W register is loaded with an offset into the table before executing a call to that table. The first instruction of the called routine is the ADDWF PCL instruction. The next instruction executed will be one of the RETLW nn instructions that returns the value ‘nn’ to the calling function. The offset value (in WREG) specifies the number of bytes that the program counter should advance and should be multiples of 2 (LSb = 0). In this method, only one data byte may be stored in each instruction location and room on the return address stack is required. EXAMPLE 5-2: COMPUTED GOTO USING AN OFFSET VALUE 5.1.4.2 Table Reads and Table Writes A better method of storing data in program memory allows two bytes of data to be stored in each instruction location. Look-up table data may be stored two bytes per program word by using table reads and writes. The Table Pointer (TBLPTR) register specifies the byte address and the Table Latch (TABLAT) register contains the data that is read from or written to program memory. Data is transferred to or from program memory one byte at a time. Table read and table write operations are discussed further in Section 6.1 “Table Reads and Table Writes”. CALL SUB1, FAST ;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK • • SUB1 • • RETURN, FAST ;RESTORE VALUES SAVED ;IN FAST REGISTER STACK MOVF OFFSET, W CALL TABLE ORG nn00h TABLE ADDWF PCL RETLW nnh RETLW nnh RETLW nnh . . .© 2008 Microchip Technology Inc. DS39631E-page 57 PIC18F2420/2520/4420/4520 5.2 PIC18 Instruction Cycle 5.2.1 CLOCKING SCHEME The microcontroller clock input, whether from an internal or external source, is internally divided by four to generate four non-overlapping quadrature clocks (Q1, Q2, Q3 and Q4). Internally, the program counter is incremented on every Q1; the instruction is fetched from the program memory and latched into the instruction register during Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 5-3. 5.2.2 INSTRUCTION FLOW/PIPELINING An “Instruction Cycle” consists of four Q cycles: Q1 through Q4. The instruction fetch and execute are pipelined in such a manner that a fetch takes one instruction cycle, while the decode and execute take another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g., GOTO), then two cycles are required to complete the instruction (Example 5-3). A fetch cycle begins with the Program Counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the Instruction Register (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3 and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write). FIGURE 5-3: CLOCK/INSTRUCTION CYCLE EXAMPLE 5-3: INSTRUCTION PIPELINE FLOW Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Q3 Q4 PC OSC2/CLKO (RC mode) PC PC + 2 PC + 4 Fetch INST (PC) Execute INST (PC – 2) Fetch INST (PC + 2) Execute INST (PC) Fetch INST (PC + 4) Execute INST (PC + 2) Internal Phase Clock All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction is “flushed” from the pipeline while the new instruction is being fetched and then executed. TCY0 TCY1 TCY2 TCY3 TCY4 TCY5 1. MOVLW 55h Fetch 1 Execute 1 2. MOVWF PORTB Fetch 2 Execute 2 3. BRA SUB_1 Fetch 3 Execute 3 4. BSF PORTA, BIT3 (Forced NOP) Fetch 4 Flush (NOP) 5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1PIC18F2420/2520/4420/4520 DS39631E-page 58 © 2008 Microchip Technology Inc. 5.2.3 INSTRUCTIONS IN PROGRAM MEMORY The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program memory. The Least Significant Byte of an instruction word is always stored in a program memory location with an even address (LSb = 0). To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSb will always read ‘0’ (see Section 5.1.1 “Program Counter”). Figure 5-4 shows an example of how instruction words are stored in the program memory. The CALL and GOTO instructions have the absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, the data contained in the instruction is a word address. The word address is written to PC<20:1>, which accesses the desired byte address in program memory. Instruction #2 in Figure 5-4 shows how the instruction GOTO 0006h is encoded in the program memory. Program branch instructions, which encode a relative address offset, operate in the same manner. The offset value stored in a branch instruction represents the number of single-word instructions that the PC will be offset by. Section 24.0 “Instruction Set Summary” provides further details of the instruction set. FIGURE 5-4: INSTRUCTIONS IN PROGRAM MEMORY 5.2.4 TWO-WORD INSTRUCTIONS The standard PIC18 instruction set has four two-word instructions: CALL, MOVFF, GOTO and LSFR. In all cases, the second word of the instructions always has ‘1111’ as its four Most Significant bits; the other 12 bits are literal data, usually a data memory address. The use of ‘1111’ in the 4 MSbs of an instruction specifies a special form of NOP. If the instruction is executed in proper sequence – immediately after the first word – the data in the second word is accessed and used by the instruction sequence. If the first word is skipped for some reason and the second word is executed by itself, a NOP is executed instead. This is necessary for cases when the two-word instruction is preceded by a conditional instruction that changes the PC. Example 5-4 shows how this works. EXAMPLE 5-4: TWO-WORD INSTRUCTIONS Word Address LSB = 1 LSB = 0 ↓ Program Memory Byte Locations → 000000h 000002h 000004h 000006h Instruction 1: MOVLW 055h 0Fh 55h 000008h Instruction 2: GOTO 0006h EFh 03h 00000Ah F0h 00h 00000Ch Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh F4h 56h 000010h 000012h 000014h Note: See Section 5.6 “PIC18 Instruction Execution and the Extended Instruction Set” for information on two-word instructions in the extended instruction set. CASE 1: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; No, skip this word 1111 0100 0101 0110 ; Execute this word as a NOP 0010 0100 0000 0000 ADDWF REG3 ; continue code CASE 2: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes, execute this word 1111 0100 0101 0110 ; 2nd word of instruction 0010 0100 0000 0000 ADDWF REG3 ; continue code© 2008 Microchip Technology Inc. DS39631E-page 59 PIC18F2420/2520/4420/4520 5.3 Data Memory Organization The data memory in PIC18 devices is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. The memory space is divided into as many as 16 banks that contain 256 bytes each; PIC18F2420/ 2520/4420/4520 devices implement all 16 banks. Figure 5-5 shows the data memory organization for the PIC18F2420/2520/4420/4520 devices. The data memory contains Special Function Registers (SFRs) and General Purpose Registers (GPRs). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratchpad operations in the user’s application. Any read of an unimplemented location will read as ‘0’s. The instruction set and architecture allow operations across all banks. The entire data memory may be accessed by Direct, Indirect or Indexed Addressing modes. Addressing modes are discussed later in this subsection. To ensure that commonly used registers (SFRs and select GPRs) can be accessed in a single cycle, PIC18 devices implement an Access Bank. This is a 256-byte memory space that provides fast access to SFRs and the lower portion of GPR Bank 0 without using the BSR. Section 5.3.2 “Access Bank” provides a detailed description of the Access RAM. 5.3.1 BANK SELECT REGISTER (BSR) Large areas of data memory require an efficient addressing scheme to make rapid access to any address possible. Ideally, this means that an entire address does not need to be provided for each read or write operation. For PIC18 devices, this is accomplished with a RAM banking scheme. This divides the memory space into 16 contiguous banks of 256 bytes. Depending on the instruction, each location can be addressed directly by its full 12-bit address, or an 8-bit low-order address and a 4-bit Bank Pointer. Most instructions in the PIC18 instruction set make use of the Bank Pointer, known as the Bank Select Register (BSR). This SFR holds the 4 Most Significant bits of a location’s address; the instruction itself includes the 8 Least Significant bits. Only the four lower bits of the BSR are implemented (BSR<3:0>). The upper four bits are unused; they will always read ‘0’ and cannot be written to. The BSR can be loaded directly by using the MOVLB instruction. The value of the BSR indicates the bank in data memory; the 8 bits in the instruction show the location in the bank and can be thought of as an offset from the bank’s lower boundary. The relationship between the BSR’s value and the bank division in data memory is shown in Figure 5-7. Since up to 16 registers may share the same low-order address, the user must always be careful to ensure that the proper bank is selected before performing a data read or write. For example, writing what should be program data to an 8-bit address of F9h while the BSR is 0Fh will end up resetting the program counter. While any bank can be selected, only those banks that are actually implemented can be read or written to. Writes to unimplemented banks are ignored, while reads from unimplemented banks will return ‘0’s. Even so, the STATUS register will still be affected as if the operation was successful. The data memory map in Figure 5-5 indicates which banks are implemented. In the core PIC18 instruction set, only the MOVFF instruction fully specifies the 12-bit address of the source and target registers. This instruction ignores the BSR completely when it executes. All other instructions include only the low-order address as an operand and must use either the BSR or the Access Bank to locate their target registers. Note: The operation of some aspects of data memory are changed when the PIC18 extended instruction set is enabled. See Section 5.5 “Data Memory and the Extended Instruction Set” for more information.PIC18F2420/2520/4420/4520 DS39631E-page 60 © 2008 Microchip Technology Inc. FIGURE 5-5: DATA MEMORY MAP FOR PIC18F2420/4420 DEVICES Bank 0 Bank 1 Bank 14 Bank 15 BSR<3:0> Data Memory Map = 0000 = 0001 = 1111 080h 07Fh F80h FFFh 00h 7Fh 80h FFh Access Bank When ‘a’ = 0: The BSR is ignored and the Access Bank is used. The first 128 bytes are general purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15). When ‘a’ = 1: The BSR specifies the Bank used by the instruction. F7Fh F00h EFFh 1FFh 100h 0FFh 000h Access RAM FFh 00h FFh 00h FFh 00h GPR GPR SFR Access RAM High Access RAM Low Bank 2 = 0110 = 0010 (SFRs) 2FFh 200h 3FFh 300h 4FFh 400h 5FFh 500h 6FFh 600h 7FFh 700h 8FFh 800h 9FFh 900h AFFh A00h BFFh B00h CFFh C00h DFFh D00h E00h Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 Bank 8 Bank 9 Bank 10 Bank 11 Bank 12 Bank 13 FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h GPR FFh 00h = 0011 = 0100 = 0101 = 0111 = 1000 = 1001 = 1010 = 1011 = 1100 = 1101 = 1110 Unused Read 00h Unused© 2008 Microchip Technology Inc. DS39631E-page 61 PIC18F2420/2520/4420/4520 FIGURE 5-6: DATA MEMORY MAP FOR PIC18F2520/4520 DEVICES Bank 0 Bank 1 Bank 14 Bank 15 BSR<3:0> Data Memory Map = 0000 = 0001 = 1111 080h 07Fh F80h FFFh 00h 7Fh 80h FFh Access Bank When ‘a’ = 0: The BSR is ignored and the Access Bank is used. The first 128 bytes are general purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15). When ‘a’ = 1: The BSR specifies the Bank used by the instruction. F7Fh F00h EFFh 1FFh 100h 0FFh 000h Access RAM FFh 00h FFh 00h FFh 00h GPR GPR SFR Access RAM High Access RAM Low Bank 2 = 0110 = 0010 (SFRs) 2FFh 200h 3FFh 300h 4FFh 400h 5FFh 500h 6FFh 600h 7FFh 700h 8FFh 800h 9FFh 900h AFFh A00h BFFh B00h CFFh C00h DFFh D00h E00h Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 Bank 8 Bank 9 Bank 10 Bank 11 Bank 12 Bank 13 FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h GPR FFh 00h = 0011 = 0100 = 0101 = 0111 = 1000 = 1001 = 1010 = 1011 = 1100 = 1101 = 1110 Unused Read 00h Unused GPR GPR GPRPIC18F2420/2520/4420/4520 DS39631E-page 62 © 2008 Microchip Technology Inc. FIGURE 5-7: USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING) 5.3.2 ACCESS BANK While the use of the BSR with an embedded 8-bit address allows users to address the entire range of data memory, it also means that the user must always ensure that the correct bank is selected. Otherwise, data may be read from or written to the wrong location. This can be disastrous if a GPR is the intended target of an operation, but an SFR is written to instead. Verifying and/or changing the BSR for each read or write to data memory can become very inefficient. To streamline access for the most commonly used data memory locations, the data memory is configured with an Access Bank, which allows users to access a mapped block of memory without specifying a BSR. The Access Bank consists of the first 128 bytes of memory (00h-7Fh) in Bank 0 and the last 128 bytes of memory (80h-FFh) in Block 15. The lower half is known as the “Access RAM” and is composed of GPRs. This upper half is also where the device’s SFRs are mapped. These two areas are mapped contiguously in the Access Bank and can be addressed in a linear fashion by an 8-bit address (Figure 5-5). The Access Bank is used by core PIC18 instructions that include the Access RAM bit (the ‘a’ parameter in the instruction). When ‘a’ is equal to ‘1’, the instruction uses the BSR and the 8-bit address included in the opcode for the data memory address. When ‘a’ is ‘0’, however, the instruction is forced to use the Access Bank address map; the current value of the BSR is ignored entirely. Using this “forced” addressing allows the instruction to operate on a data address in a single cycle, without updating the BSR first. For 8-bit addresses of 80h and above, this means that users can evaluate and operate on SFRs more efficiently. The Access RAM below 80h is a good place for data values that the user might need to access rapidly, such as immediate computational results or common program variables. Access RAM also allows for faster and more code efficient context saving and switching of variables. The mapping of the Access Bank is slightly different when the extended instruction set is enabled (XINST Configuration bit = 1). This is discussed in more detail in Section 5.5.3 “Mapping the Access Bank in Indexed Literal Offset Mode”. 5.3.3 GENERAL PURPOSE REGISTER FILE PIC18 devices may have banked memory in the GPR area. This is data RAM, which is available for use by all instructions. GPRs start at the bottom of Bank 0 (address 000h) and grow upwards towards the bottom of the SFR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other Resets. Note 1: The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the registers of the Access Bank. 2: The MOVFF instruction embeds the entire 12-bit address in the instruction. Data Memory Bank Select(2) 7 0 From Opcode(2) 0000 000h 100h 200h 300h F00h E00h FFFh Bank 0 Bank 1 Bank 2 Bank 14 Bank 15 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh Bank 3 through Bank 13 0011 11111111 7 0 BSR(1)© 2008 Microchip Technology Inc. DS39631E-page 63 PIC18F2420/2520/4420/4520 5.3.4 SPECIAL FUNCTION REGISTERS The Special Function Registers (SFRs) are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. SFRs start at the top of data memory (FFFh) and extend downward to occupy the top half of Bank 15 (F80h to FFFh). A list of these registers is given in Table 5-1 and Table 5-2. The SFRs can be classified into two sets: those associated with the “core” device functionality (ALU, Resets and interrupts) and those related to the peripheral functions. The Reset and Interrupt registers are described in their respective chapters, while the ALU’s STATUS register is described later in this section. Registers related to the operation of a peripheral feature are described in the chapter for that peripheral. The SFRs are typically distributed among the peripherals whose functions they control. Unused SFR locations are unimplemented and read as ‘0’s. TABLE 5-1: SPECIAL FUNCTION REGISTER MAP FOR PIC18F2420/2520/4420/4520 DEVICES Address Name Address Name Address Name Address Name FFFh TOSU FDFh INDF2(1) FBFh CCPR1H F9Fh IPR1 FFEh TOSH FDEh POSTINC2(1) FBEh CCPR1L F9Eh PIR1 FFDh TOSL FDDh POSTDEC2(1) FBDh CCP1CON F9Dh PIE1 FFCh STKPTR FDCh PREINC2(1) FBCh CCPR2H F9Ch —(2) FFBh PCLATU FDBh PLUSW2(1) FBBh CCPR2L F9Bh OSCTUNE FFAh PCLATH FDAh FSR2H FBAh CCP2CON F9Ah —(2) FF9h PCL FD9h FSR2L FB9h —(2) F99h —(2) FF8h TBLPTRU FD8h STATUS FB8h BAUDCON F98h —(2) FF7h TBLPTRH FD7h TMR0H FB7h PWM1CON(3) F97h —(2) FF6h TBLPTRL FD6h TMR0L FB6h ECCP1AS(3) F96h TRISE(3) FF5h TABLAT FD5h T0CON FB5h CVRCON F95h TRISD(3) FF4h PRODH FD4h —(2) FB4h CMCON F94h TRISC FF3h PRODL FD3h OSCCON FB3h TMR3H F93h TRISB FF2h INTCON FD2h HLVDCON FB2h TMR3L F92h TRISA FF1h INTCON2 FD1h WDTCON FB1h T3CON F91h —(2) FF0h INTCON3 FD0h RCON FB0h SPBRGH F90h —(2) FEFh INDF0(1) FCFh TMR1H FAFh SPBRG F8Fh —(2) FEEh POSTINC0(1) FCEh TMR1L FAEh RCREG F8Eh —(2) FEDh POSTDEC0(1) FCDh T1CON FADh TXREG F8Dh LATE(3) FECh PREINC0(1) FCCh TMR2 FACh TXSTA F8Ch LATD(3) FEBh PLUSW0(1) FCBh PR2 FABh RCSTA F8Bh LATC FEAh FSR0H FCAh T2CON FAAh —(2) F8Ah LATB FE9h FSR0L FC9h SSPBUF FA9h EEADR F89h LATA FE8h WREG FC8h SSPADD FA8h EEDATA F88h —(2) FE7h INDF1(1) FC7h SSPSTAT FA7h EECON2(1) F87h —(2) FE6h POSTINC1(1) FC6h SSPCON1 FA6h EECON1 F86h —(2) FE5h POSTDEC1(1) FC5h SSPCON2 FA5h —(2) F85h —(2) FE4h PREINC1(1) FC4h ADRESH FA4h —(2) F84h PORTE(3) FE3h PLUSW1(1) FC3h ADRESL FA3h —(2) F83h PORTD(3) FE2h FSR1H FC2h ADCON0 FA2h IPR2 F82h PORTC FE1h FSR1L FC1h ADCON1 FA1h PIR2 F81h PORTB FE0h BSR FC0h ADCON2 FA0h PIE2 F80h PORTA Note 1: This is not a physical register. 2: Unimplemented registers are read as ‘0’. 3: This register is not available on 28-pin devices.PIC18F2420/2520/4420/4520 DS39631E-page 64 © 2008 Microchip Technology Inc. TABLE 5-2: PIC18F2420/2520/4420/4520 REGISTER FILE SUMMARY File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: TOSU — — — Top-of-Stack Upper Byte (TOS<20:16>) ---0 0000 49, 54 TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 49, 54 TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 49, 54 STKPTR STKFUL STKUNF — SP4 SP3 SP2 SP1 SP0 00-0 0000 49, 55 PCLATU — — — Holding Register for PC<20:16> ---0 0000 49, 54 PCLATH Holding Register for PC<15:8> 0000 0000 49, 54 PCL PC Low Byte (PC<7:0>) 0000 0000 49, 54 TBLPTRU — — bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 49, 76 TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 49, 76 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 49, 76 TABLAT Program Memory Table Latch 0000 0000 49, 76 PRODH Product Register High Byte xxxx xxxx 49, 89 PRODL Product Register Low Byte xxxx xxxx 49, 89 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 49, 93 INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP 1111 -1-1 49, 94 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 49, 95 INDF0 Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register) N/A 49, 69 POSTINC0 Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register) N/A 49, 69 POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register) N/A 49, 69 PREINC0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) N/A 49, 69 PLUSW0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) – value of FSR0 offset by W N/A 49, 69 FSR0H — — — — Indirect Data Memory Address Pointer 0 High Byte ---- 0000 49, 69 FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 49, 69 WREG Working Register xxxx xxxx 49 INDF1 Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register) N/A 49, 69 POSTINC1 Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register) N/A 49, 69 POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register) N/A 49, 69 PREINC1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) N/A 49, 69 PLUSW1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) – value of FSR1 offset by W N/A 49, 69 FSR1H — — — — Indirect Data Memory Address Pointer 1 High Byte ---- 0000 50, 69 FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 50, 69 BSR — — — — Bank Select Register ---- 0000 50, 59 INDF2 Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register) N/A 50, 69 POSTINC2 Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register) N/A 50, 69 POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register) N/A 50, 69 PREINC2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) N/A 50, 69 PLUSW2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) – value of FSR2 offset by W N/A 50, 69 FSR2H — — — — Indirect Data Memory Address Pointer 2 High Byte ---- 0000 50, 69 FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 50, 69 STATUS — — — N OV Z DC C ---x xxxx 50, 67 Legend: x = unknown, u = unchanged, — = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as ‘0’. Note 1: The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, it is disabled and reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”. 2: These registers and/or bits are not implemented on 28-pin devices and are read as ‘0’. Reset values are shown for 40/44-pin devices; individual unimplemented bits should be interpreted as ‘-’. 3: The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in INTOSC Modes”. 4: The RE3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); otherwise, RE3 reads as ‘0’. This bit is read-only. 5: RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’.© 2008 Microchip Technology Inc. DS39631E-page 65 PIC18F2420/2520/4420/4520 TMR0H Timer0 Register High Byte 0000 0000 50, 125 TMR0L Timer0 Register Low Byte xxxx xxxx 50, 125 T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 50, 123 OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 0100 q000 30, 50 HLVDCON VDIRMAG — IRVST HLVDEN HLVDL3 HLVDL2 HLVDL1 HLVDL0 0-00 0101 50, 245 WDTCON — — — — — — — SWDTEN --- ---0 50, 259 RCON IPEN SBOREN(1) — RI TO PD POR BOR 0q-1 11q0 42, 48, 102 TMR1H Timer1 Register High Byte xxxx xxxx 50, 132 TMR1L Timer1 Register Low Bytes xxxx xxxx 50, 132 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 50, 127 TMR2 Timer2 Register 0000 0000 50, 134 PR2 Timer2 Period Register 1111 1111 50, 134 T2CON — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 50, 133 SSPBUF MSSP Receive Buffer/Transmit Register xxxx xxxx 50, 169, 170 SSPADD MSSP Address Register in I2C™ Slave Mode. MSSP Baud Rate Reload Register in I2C Master Mode. 0000 0000 50, 170 SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 50, 162, 171 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 50, 163, 172 SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 50, 173 ADRESH A/D Result Register High Byte xxxx xxxx 51, 232 ADRESL A/D Result Register Low Byte xxxx xxxx 51, 232 ADCON0 — — CHS3 CHS2 CHS1 CHS0 GO/DONE ADON --00 0000 51, 223 ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 --00 0qqq 51, 224 ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0-00 0000 51, 225 CCPR1H Capture/Compare/PWM Register 1 High Byte xxxx xxxx 51, 140 CCPR1L Capture/Compare/PWM Register 1 Low Byte xxxx xxxx 51, 140 CCP1CON P1M1(2) P1M0(2) DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 51, 139, 147 CCPR2H Capture/Compare/PWM Register 2 High Byte xxxx xxxx 51, 140 CCPR2L Capture/Compare/PWM Register 2 Low Byte xxxx xxxx 51, 140 CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 51, 139 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 0100 0-00 51, 204 PWM1CON PRSEN PDC6(2) PDC5(2) PDC4(2) PDC3(2) PDC2(2) PDC1(2) PDC0(2) 0000 0000 51, 156 ECCP1AS ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1(2) PSSBD0(2) 0000 0000 51, 157 CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 0000 0000 51, 239 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0111 51, 233 TMR3H Timer3 Register High Byte xxxx xxxx 51, 137 TMR3L Timer3 Register Low Byte xxxx xxxx 51, 137 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 51, 135 TABLE 5-2: PIC18F2420/2520/4420/4520 REGISTER FILE SUMMARY (CONTINUED) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: Legend: x = unknown, u = unchanged, — = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as ‘0’. Note 1: The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, it is disabled and reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”. 2: These registers and/or bits are not implemented on 28-pin devices and are read as ‘0’. Reset values are shown for 40/44-pin devices; individual unimplemented bits should be interpreted as ‘-’. 3: The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in INTOSC Modes”. 4: The RE3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); otherwise, RE3 reads as ‘0’. This bit is read-only. 5: RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’.PIC18F2420/2520/4420/4520 DS39631E-page 66 © 2008 Microchip Technology Inc. SPBRGH EUSART Baud Rate Generator Register High Byte 0000 0000 51, 206 SPBRG EUSART Baud Rate Generator Register Low Byte 0000 0000 51, 206 RCREG EUSART Receive Register 0000 0000 51, 213 TXREG EUSART Transmit Register 0000 0000 51, 211 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 51, 202 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 51, 203 EEADR EEPROM Address Register 0000 0000 51, 74, 83 EEDATA EEPROM Data Register 0000 0000 51, 74, 83 EECON2 EEPROM Control Register 2 (not a physical register) 0000 0000 51, 74, 83 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 51, 75, 84 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 11-1 1111 52, 101 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 00-0 0000 52, 97 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 00-0 0000 52, 99 IPR1 PSPIP(2) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 1111 1111 52, 100 PIR1 PSPIF(2) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 52, 96 PIE1 PSPIE(2) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 52, 98 OSCTUNE INTSRC PLLEN(3) — TUN4 TUN3 TUN2 TUN1 TUN0 0q-0 0000 27, 52 TRISE(2) IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 0000 -111 52, 118 TRISD(2) PORTD Data Direction Register 1111 1111 52, 114 TRISC PORTC Data Direction Register 1111 1111 52, 111 TRISB PORTB Data Direction Register 1111 1111 52, 108 TRISA TRISA7(5) TRISA6(5) PORTA Data Direction Register 1111 1111 52, 105 LATE(2) — — — — — PORTE Data Latch Register (Read and Write to Data Latch) ---- -xxx 52, 117 LATD(2) PORTD Data Latch Register (Read and Write to Data Latch) xxxx xxxx 52, 114 LATC PORTC Data Latch Register (Read and Write to Data Latch) xxxx xxxx 52, 111 LATB PORTB Data Latch Register (Read and Write to Data Latch) xxxx xxxx 52, 108 LATA LATA7(5) LATA6(5) PORTA Data Latch Register (Read and Write to Data Latch) xxxx xxxx 52, 105 PORTE — — — — RE3(4) RE2(2) RE1(2) RE0(2) ---- xxxx 52, 117 PORTD(2) RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx 52, 114 PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx 52, 111 PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx 52, 108 PORTA RA7(5) RA6(5) RA5 RA4 RA3 RA2 RA1 RA0 xx0x 0000 52, 105 TABLE 5-2: PIC18F2420/2520/4420/4520 REGISTER FILE SUMMARY (CONTINUED) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: Legend: x = unknown, u = unchanged, — = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as ‘0’. Note 1: The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, it is disabled and reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”. 2: These registers and/or bits are not implemented on 28-pin devices and are read as ‘0’. Reset values are shown for 40/44-pin devices; individual unimplemented bits should be interpreted as ‘-’. 3: The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in INTOSC Modes”. 4: The RE3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); otherwise, RE3 reads as ‘0’. This bit is read-only. 5: RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’.© 2008 Microchip Technology Inc. DS39631E-page 67 PIC18F2420/2520/4420/4520 5.3.5 STATUS REGISTER The STATUS register, shown in Register 5-2, contains the arithmetic status of the ALU. As with any other SFR, it can be the operand for any instruction. If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV or N bits, the results of the instruction are not written; instead, the STATUS register is updated according to the instruction performed. Therefore, the result of an instruction with the STATUS register as its destination may be different than intended. As an example, CLRF STATUS will set the Z bit and leave the remaining Status bits unchanged (‘000u u1uu’). It is recommended that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the STATUS register, because these instructions do not affect the Z, C, DC, OV or N bits in the STATUS register. For other instructions that do not affect Status bits, see the instruction set summaries in Table 24-2 and Table 24-3. Note: The C and DC bits operate as the borrow and digit borrow bits, respectively, in subtraction. REGISTER 5-2: STATUS REGISTER U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x — — — N OV Z DC(1) C(2) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-5 Unimplemented: Read as ‘0’ bit 4 N: Negative bit This bit is used for signed arithmetic (2’s complement). It indicates whether the result was negative (ALU MSB = 1). 1 = Result was negative 0 = Result was positive bit 3 OV: Overflow bit This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit magnitude which causes the sign bit (bit 7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred bit 2 Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero bit 1 DC: Digit Carry/borrow bit(1) For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the 4th low-order bit of the result occurred 0 = No carry-out from the 4th low-order bit of the result bit 0 C: Carry/borrow bit(2) For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred Note 1: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register. 2: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the source register.PIC18F2420/2520/4420/4520 DS39631E-page 68 © 2008 Microchip Technology Inc. 5.4 Data Addressing Modes While the program memory can be addressed in only one way – through the program counter – information in the data memory space can be addressed in several ways. For most instructions, the addressing mode is fixed. Other instructions may use up to three modes, depending on which operands are used and whether or not the extended instruction set is enabled. The addressing modes are: • Inherent • Literal • Direct • Indirect An additional addressing mode, Indexed Literal Offset, is available when the extended instruction set is enabled (XINST Configuration bit = 1). Its operation is discussed in greater detail in Section 5.5.1 “Indexed Addressing with Literal Offset”. 5.4.1 INHERENT AND LITERAL ADDRESSING Many PIC18 control instructions do not need any argument at all; they either perform an operation that globally affects the device or they operate implicitly on one register. This addressing mode is known as Inherent Addressing. Examples include SLEEP, RESET and DAW. Other instructions work in a similar way but require an additional explicit argument in the opcode. This is known as Literal Addressing mode because they require some literal value as an argument. Examples include ADDLW and MOVLW, which respectively, add or move a literal value to the W register. Other examples include CALL and GOTO, which include a 20-bit program memory address. 5.4.2 DIRECT ADDRESSING Direct Addressing specifies all or part of the source and/or destination address of the operation within the opcode itself. The options are specified by the arguments accompanying the instruction. In the core PIC18 instruction set, bit-oriented and byteoriented instructions use some version of Direct Addressing by default. All of these instructions include some 8-bit literal address as their Least Significant Byte. This address specifies either a register address in one of the banks of data RAM (Section 5.3.3 “General Purpose Register File”) or a location in the Access Bank (Section 5.3.2 “Access Bank”) as the data source for the instruction. The Access RAM bit ‘a’ determines how the address is interpreted. When ‘a’ is ‘1’, the contents of the BSR (Section 5.3.1 “Bank Select Register (BSR)”) are used with the address to determine the complete 12-bit address of the register. When ‘a’ is ‘0’, the address is interpreted as being a register in the Access Bank. Addressing that uses the Access RAM is sometimes also known as Direct Forced Addressing mode. A few instructions, such as MOVFF, include the entire 12-bit address (either source or destination) in their opcodes. In these cases, the BSR is ignored entirely. The destination of the operation’s results is determined by the destination bit ‘d’. When ‘d’ is ‘1’, the results are stored back in the source register, overwriting its original contents. When ‘d’ is ‘0’, the results are stored in the W register. Instructions without the ‘d’ argument have a destination that is implicit in the instruction; their destination is either the target register being operated on or the W register. 5.4.3 INDIRECT ADDRESSING Indirect Addressing allows the user to access a location in data memory without giving a fixed address in the instruction. This is done by using File Select Registers (FSRs) as pointers to the locations to be read or written to. Since the FSRs are themselves located in RAM as Special Function Registers, they can also be directly manipulated under program control. This makes FSRs very useful in implementing data structures, such as tables and arrays in data memory. The registers for Indirect Addressing are also implemented with Indirect File Operands (INDFs) that permit automatic manipulation of the pointer value with auto-incrementing, auto-decrementing or offsetting with another value. This allows for efficient code, using loops, such as the example of clearing an entire RAM bank in Example 5-5. EXAMPLE 5-5: HOW TO CLEAR RAM (BANK 1) USING INDIRECT ADDRESSING Note: The execution of some instructions in the core PIC18 instruction set are changed when the PIC18 extended instruction set is enabled. See Section 5.5 “Data Memory and the Extended Instruction Set” for more information. LFSR FSR0, 100h; NEXT CLRF POSTINC0 ; Clear INDF ; register then ; inc pointer BTFSS FSR0H, 1; All done with ; Bank1? BRA NEXT ; NO, clear next CONTINUE ; YES, continue © 2008 Microchip Technology Inc. DS39631E-page 69 PIC18F2420/2520/4420/4520 5.4.3.1 FSR Registers and the INDF Operand At the core of Indirect Addressing are three sets of registers: FSR0, FSR1 and FSR2. Each represents a pair of 8-bit registers, FSRnH and FSRnL. The four upper bits of the FSRnH register are not used so each FSR pair holds a 12-bit value. This represents a value that can address the entire range of the data memory in a linear fashion. The FSR register pairs, then, serve as pointers to data memory locations. Indirect Addressing is accomplished with a set of Indirect File Operands, INDF0 through INDF2. These can be thought of as “virtual” registers: they are mapped in the SFR space but are not physically implemented. Reading or writing to a particular INDF register actually accesses its corresponding FSR register pair. A read from INDF1, for example, reads the data at the address indicated by FSR1H:FSR1L. Instructions that use the INDF registers as operands actually use the contents of their corresponding FSR as a pointer to the instruction’s target. The INDF operand is just a convenient way of using the pointer. Because Indirect Addressing uses a full 12-bit address, data RAM banking is not necessary. Thus, the current contents of the BSR and the Access RAM bit have no effect on determining the target address. 5.4.3.2 FSR Registers and POSTINC, POSTDEC, PREINC and PLUSW In addition to the INDF operand, each FSR register pair also has four additional indirect operands. Like INDF, these are “virtual” registers that cannot be indirectly read or written to. Accessing these registers actually accesses the associated FSR register pair, but also performs a specific action on it stored value. They are: • POSTDEC: accesses the FSR value, then automatically decrements it by 1 afterwards • POSTINC: accesses the FSR value, then automatically increments it by 1 afterwards • PREINC: increments the FSR value by 1, then uses it in the operation • PLUSW: adds the signed value of the W register (range of -127 to 128) to that of the FSR and uses the new value in the operation. In this context, accessing an INDF register uses the value in the FSR registers without changing them. Similarly, accessing a PLUSW register gives the FSR value offset by that in the W register; neither value is actually changed in the operation. Accessing the other virtual registers changes the value of the FSR registers. Operations on the FSRs with POSTDEC, POSTINC and PREINC affect the entire register pair; that is, rollovers of the FSRnL register from FFh to 00h carry over to the FSRnH register. On the other hand, results of these operations do not change the value of any flags in the STATUS register (e.g., Z, N, OV, etc.). FIGURE 5-8: INDIRECT ADDRESSING FSR1H:FSR1L 7 0 Data Memory 000h 100h 200h 300h F00h E00h FFFh Bank 0 Bank 1 Bank 2 Bank 14 Bank 15 Bank 3 through Bank 13 ADDWF, INDF1, 1 7 0 Using an instruction with one of the Indirect Addressing registers as the operand.... ...uses the 12-bit address stored in the FSR pair associated with that register.... ...to determine the data memory location to be used in that operation. In this case, the FSR1 pair contains ECCh. This means the contents of location ECCh will be added to that of the W register and stored back in ECCh. xxxx 1110 11001100PIC18F2420/2520/4420/4520 DS39631E-page 70 © 2008 Microchip Technology Inc. The PLUSW register can be used to implement a form of Indexed Addressing in the data memory space. By manipulating the value in the W register, users can reach addresses that are fixed offsets from pointer addresses. In some applications, this can be used to implement some powerful program control structure, such as software stacks, inside of data memory. 5.4.3.3 Operations by FSRs on FSRs Indirect Addressing operations that target other FSRs or virtual registers represent special cases. For example, using an FSR to point to one of the virtual registers will not result in successful operations. As a specific case, assume that FSR0H:FSR0L contains FE7h, the address of INDF1. Attempts to read the value of the INDF1 using INDF0 as an operand will return 00h. Attempts to write to INDF1 using INDF0 as the operand will result in a NOP. On the other hand, using the virtual registers to write to an FSR pair may not occur as planned. In these cases, the value will be written to the FSR pair but without any incrementing or decrementing. Thus, writing to INDF2 or POSTDEC2 will write the same value to the FSR2H:FSR2L. Since the FSRs are physical registers mapped in the SFR space, they can be manipulated through all direct operations. Users should proceed cautiously when working on these registers, particularly if their code uses indirect addressing. Similarly, operations by Indirect Addressing are generally permitted on all other SFRs. Users should exercise the appropriate caution that they do not inadvertently change settings that might affect the operation of the device. 5.5 Data Memory and the Extended Instruction Set Enabling the PIC18 extended instruction set (XINST Configuration bit = 1) significantly changes certain aspects of data memory and its addressing. Specifically, the use of the Access Bank for many of the core PIC18 instructions is different; this is due to the introduction of a new addressing mode for the data memory space. What does not change is just as important. The size of the data memory space is unchanged, as well as its linear addressing. The SFR map remains the same. Core PIC18 instructions can still operate in both Direct and Indirect Addressing mode; inherent and literal instructions do not change at all. Indirect Addressing with FSR0 and FSR1 also remains unchanged. 5.5.1 INDEXED ADDRESSING WITH LITERAL OFFSET Enabling the PIC18 extended instruction set changes the behavior of Indirect Addressing using the FSR2 register pair within Access RAM. Under the proper conditions, instructions that use the Access Bank – that is, most bit-oriented and byte-oriented instructions – can invoke a form of Indexed Addressing using an offset specified in the instruction. This special addressing mode is known as Indexed Addressing with Literal Offset, or Indexed Literal Offset mode. When using the extended instruction set, this addressing mode requires the following: • The use of the Access Bank is forced (‘a’ = 0) and • The file address argument is less than or equal to 5Fh. Under these conditions, the file address of the instruction is not interpreted as the lower byte of an address (used with the BSR in direct addressing), or as an 8-bit address in the Access Bank. Instead, the value is interpreted as an offset value to an Address Pointer, specified by FSR2. The offset and the contents of FSR2 are added to obtain the target address of the operation. 5.5.2 INSTRUCTIONS AFFECTED BY INDEXED LITERAL OFFSET MODE Any of the core PIC18 instructions that can use Direct Addressing are potentially affected by the Indexed Literal Offset Addressing mode. This includes all byte-oriented and bit-oriented instructions, or almost one-half of the standard PIC18 instruction set. Instructions that only use Inherent or Literal Addressing modes are unaffected. Additionally, byte-oriented and bit-oriented instructions are not affected if they do not use the Access Bank (Access RAM bit is ‘1’), or include a file address of 60h or above. Instructions meeting these criteria will continue to execute as before. A comparison of the different possible addressing modes when the extended instruction set is enabled in shown in Figure 5-9. Those who desire to use byte-oriented or bit-oriented instructions in the Indexed Literal Offset mode should note the changes to assembler syntax for this mode. This is described in more detail in Section 24.2.1 “Extended Instruction Syntax”.© 2008 Microchip Technology Inc. DS39631E-page 71 PIC18F2420/2520/4420/4520 FIGURE 5-9: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED) EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff) When ‘a’ = 0 and f ≥ 60h: The instruction executes in Direct Forced mode. ‘f’ is interpreted as a location in the Access RAM between 060h and 0FFh. This is the same as locations 060h to 07Fh (Bank 0) and F80h to FFFh (Bank 15) of data memory. Locations below 60h are not available in this addressing mode. When ‘a’ = 0 and f ≤ 5Fh: The instruction executes in Indexed Literal Offset mode. ‘f’ is interpreted as an offset to the address value in FSR2. The two are added together to obtain the address of the target register for the instruction. The address can be anywhere in the data memory space. Note that in this mode, the correct syntax is now: ADDWF [k], d where ‘k’ is the same as ‘f’. When ‘a’ = 1 (all values of f): The instruction executes in Direct mode (also known as Direct Long mode). ‘f’ is interpreted as a location in one of the 16 banks of the data memory space. The bank is designated by the Bank Select Register (BSR). The address can be in any implemented bank in the data memory space. 000h 060h 100h F00h F80h FFFh Valid range 00h 60h 80h FFh Data Memory Access RAM Bank 0 Bank 1 through Bank 14 Bank 15 SFRs 000h 080h 100h F00h F80h FFFh Data Memory Bank 0 Bank 1 through Bank 14 Bank 15 SFRs FSR2H FSR2L 001001da ffffffff 001001da ffffffff 000h 080h 100h F00h F80h FFFh Data Memory Bank 0 Bank 1 through Bank 14 Bank 15 SFRs for ‘f’ BSR 00000000 080hPIC18F2420/2520/4420/4520 DS39631E-page 72 © 2008 Microchip Technology Inc. 5.5.3 MAPPING THE ACCESS BANK IN INDEXED LITERAL OFFSET MODE The use of Indexed Literal Offset Addressing mode effectively changes how the first 96 locations of Access RAM (00h to 5Fh) are mapped. Rather than containing just the contents of the bottom half of Bank 0, this mode maps the contents from Bank 0 and a user-defined “window” that can be located anywhere in the data memory space. The value of FSR2 establishes the lower boundary of the addresses mapped into the window, while the upper boundary is defined by FSR2 plus 95 (5Fh). Addresses in the Access RAM above 5Fh are mapped as previously described (see Section 5.3.2 “Access Bank”). An example of Access Bank remapping in this addressing mode is shown in Figure 5-10. Remapping of the Access Bank applies only to operations using the Indexed Literal Offset mode. Operations that use the BSR (Access RAM bit is ‘1’) will continue to use Direct Addressing as before. 5.6 PIC18 Instruction Execution and the Extended Instruction Set Enabling the extended instruction set adds eight additional commands to the existing PIC18 instruction set. These instructions are executed as described in Section 24.2 “Extended Instruction Set”. FIGURE 5-10: REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET ADDRESSING Data Memory 000h 100h 200h F80h F00h FFFh Bank 1 Bank 15 Bank 2 through Bank 14 SFRs 05Fh ADDWF f, d, a FSR2H:FSR2L = 120h Locations in the region from the FSR2 Pointer (120h) to the pointer plus 05Fh (17Fh) are mapped to the bottom of the Access RAM (000h-05Fh). Locations in Bank 0 from 060h to 07Fh are mapped, as usual, to the middle half of the Access Bank. Special Function Registers at F80h through FFFh are mapped to 80h through FFh, as usual. Bank 0 addresses below 5Fh can still be addressed by using the BSR. Access Bank 00h 80h FFh 7Fh Bank 0 SFRs Bank 1 “Window” Bank 0 Bank 0 Window Example Situation: 07Fh 120h 17Fh 5Fh Bank 1© 2008 Microchip Technology Inc. DS39631E-page 73 PIC18F2420/2520/4420/4520 6.0 FLASH PROGRAM MEMORY The Flash program memory is readable, writable and erasable during normal operation over the entire VDD range. A read from program memory is executed on one byte at a time. A write to program memory is executed on blocks of 32 bytes at a time. Program memory is erased in blocks of 64 bytes at a time. A bulk erase operation may not be issued from user code. Writing or erasing program memory will cease instruction fetches until the operation is complete. The program memory cannot be accessed during the write or erase, therefore, code cannot execute. An internal programming timer terminates program memory writes and erases. A value written to program memory does not need to be a valid instruction. Executing a program memory location that forms an invalid instruction results in a NOP. 6.1 Table Reads and Table Writes In order to read and write program memory, there are two operations that allow the processor to move bytes between the program memory space and the data RAM: • Table Read (TBLRD) • Table Write (TBLWT) The program memory space is 16 bits wide, while the data RAM space is 8 bits wide. Table reads and table writes move data between these two memory spaces through an 8-bit register (TABLAT). Table read operations retrieve data from program memory and places it into the data RAM space. Figure 6-1 shows the operation of a table read with program memory and data RAM. Table write operations store data from the data memory space into holding registers in program memory. The procedure to write the contents of the holding registers into program memory is detailed in Section 6.5 “Writing to Flash Program Memory”. Figure 6-2 shows the operation of a table write with program memory and data RAM. Table operations work with byte entities. A table block containing data, rather than program instructions, is not required to be word aligned. Therefore, a table block can start and end at any byte address. If a table write is being used to write executable code into program memory, program instructions will need to be word aligned. FIGURE 6-1: TABLE READ OPERATION Table Pointer(1) Table Latch (8-bit) Program Memory TBLPTRH TBLPTRL TABLAT TBLPTRU Instruction: TBLRD* Note 1: The Table Pointer register points to a byte in program memory. Program Memory (TBLPTR)PIC18F2420/2520/4420/4520 DS39631E-page 74 © 2008 Microchip Technology Inc. FIGURE 6-2: TABLE WRITE OPERATION 6.2 Control Registers Several control registers are used in conjunction with the TBLRD and TBLWT instructions. These include the: • EECON1 register • EECON2 register • TABLAT register • TBLPTR registers 6.2.1 EECON1 AND EECON2 REGISTERS The EECON1 register (Register 6-1) is the control register for memory accesses. The EECON2 register is not a physical register; it is used exclusively in the memory write and erase sequences. Reading EECON2 will read all ‘0’s. The EEPGD control bit determines if the access will be a program or data EEPROM memory access. When clear, any subsequent operations will operate on the data EEPROM memory. When set, any subsequent operations will operate on the program memory. The CFGS control bit determines if the access will be to the Configuration/Calibration registers or to program memory/data EEPROM memory. When set, subsequent operations will operate on Configuration registers regardless of EEPGD (see Section 23.0 “Special Features of the CPU”). When clear, memory selection access is determined by EEPGD. The FREE bit, when set, will allow a program memory erase operation. When FREE is set, the erase operation is initiated on the next WR command. When FREE is clear, only writes are enabled. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set in hardware when the WR bit is set and cleared when the internal programming timer expires and the write operation is complete. The WR control bit initiates write operations. The bit cannot be cleared, only set, in software; it is cleared in hardware at the completion of the write operation. Table Pointer(1) Table Latch (8-bit) TBLPTRH TBLPTRL TABLAT Program Memory (TBLPTR) TBLPTRU Instruction: TBLWT* Note1: The Table Pointer actually points to one of 32 holding registers, the address of which is determined by TBLPTRL<4:0>. The process for physically writing data to the program memory array is discussed in Section 6.5 “Writing to Flash Program Memory”. Holding Registers Program Memory Note: During normal operation, the WRERR is read as ‘1’. This can indicate that a write operation was prematurely terminated by a Reset, or a write operation was attempted improperly. Note: The EEIF interrupt flag bit (PIR2<4>) is set when the write is complete. It must be cleared in software.© 2008 Microchip Technology Inc. DS39631E-page 75 PIC18F2420/2520/4420/4520 REGISTER 6-1: EECON1: EEPROM CONTROL REGISTER 1 R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD CFGS — FREE WRERR(1) WREN WR RD bit 7 bit 0 Legend: S = Settable bit (cannot be cleared in software) R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 EEPGD: Flash Program or Data EEPROM Memory Select bit 1 = Access Flash program memory 0 = Access data EEPROM memory bit 6 CFGS: Flash Program/Data EEPROM or Configuration Select bit 1 = Access Configuration registers 0 = Access Flash program or data EEPROM memory bit 5 Unimplemented: Read as ‘0’ bit 4 FREE: Flash Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only bit 3 WRERR: Flash Program/Data EEPROM Error Flag bit(1) 1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal operation, or an improper write attempt) 0 = The write operation completed bit 2 WREN: Flash Program/Data EEPROM Write Enable bit 1 = Allows write cycles to Flash program/data EEPROM 0 = Inhibits write cycles to Flash program/data EEPROM bit 1 WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle (The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete bit 0 RD: Read Control bit 1 = Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1 or CFGS = 1.) 0 = Does not initiate an EEPROM read Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition.PIC18F2420/2520/4420/4520 DS39631E-page 76 © 2008 Microchip Technology Inc. 6.2.2 TABLAT – TABLE LATCH REGISTER The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The Table Latch register is used to hold 8-bit data during data transfers between program memory and data RAM. 6.2.3 TBLPTR – TABLE POINTER REGISTER The Table Pointer (TBLPTR) register addresses a byte within the program memory. The TBLPTR is comprised of three SFR registers: Table Pointer Upper Byte, Table Pointer High Byte and Table Pointer Low Byte (TBLPTRU:TBLPTRH:TBLPTRL). These three registers join to form a 22-bit wide pointer. The low-order 21 bits allow the device to address up to 2 Mbytes of program memory space. The 22nd bit allows access to the device ID, the user ID and the Configuration bits. The Table Pointer register, TBLPTR, is used by the TBLRD and TBLWT instructions. These instructions can update the TBLPTR in one of four ways based on the table operation. These operations are shown in Table 6-1. These operations on the TBLPTR only affect the low-order 21 bits. 6.2.4 TABLE POINTER BOUNDARIES TBLPTR is used in reads, writes and erases of the Flash program memory. When a TBLRD is executed, all 22 bits of the TBLPTR determine which byte is read from program memory into TABLAT. When a TBLWT is executed, the five LSbs of the Table Pointer register (TBLPTR<4:0>) determine which of the 32 program memory holding registers is written to. When the timed write to program memory begins (via the WR bit), the 16 MSbs of the TBLPTR (TBLPTR<21:6>) determine which program memory block of 32 bytes is written to. For more detail, see Section 6.5 “Writing to Flash Program Memory”. When an erase of program memory is executed, the 16 MSbs of the Table Pointer register (TBLPTR<21:6>) point to the 64-byte block that will be erased. The Least Significant bits (TBLPTR<5:0>) are ignored. Figure 6-3 describes the relevant boundaries of TBLPTR based on Flash program memory operations. TABLE 6-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS FIGURE 6-3: TABLE POINTER BOUNDARIES BASED ON OPERATION Example Operation on Table Pointer TBLRD* TBLWT* TBLPTR is not modified TBLRD*+ TBLWT*+ TBLPTR is incremented after the read/write TBLRD*- TBLWT*- TBLPTR is decremented after the read/write TBLRD+* TBLWT+* TBLPTR is incremented before the read/write 21 16 15 8 7 0 TABLE ERASE TABLE READ – TBLPTR<21:0> TBLPTRU TBLPTRH TBLPTRL TBLPTR<21:6> TABLE WRITE – TBLPTR<21:5>© 2008 Microchip Technology Inc. DS39631E-page 77 PIC18F2420/2520/4420/4520 6.3 Reading the Flash Program Memory The TBLRD instruction is used to retrieve data from program memory and places it into data RAM. Table reads from program memory are performed one byte at a time. TBLPTR points to a byte address in program space. Executing TBLRD places the byte pointed to into TABLAT. In addition, TBLPTR can be modified automatically for the next table read operation. The internal program memory is typically organized by words. The Least Significant bit of the address selects between the high and low bytes of the word. Figure 6-4 shows the interface between the internal program memory and the TABLAT. FIGURE 6-4: READS FROM FLASH PROGRAM MEMORY EXAMPLE 6-1: READING A FLASH PROGRAM MEMORY WORD (Even Byte Address) Program Memory (Odd Byte Address) TBLRD TABLAT TBLPTR = xxxxx1 FETCH Instruction Register (IR) Read Register TBLPTR = xxxxx0 MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base MOVWF TBLPTRU ; address of the word MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL READ_WORD TBLRD*+ ; read into TABLAT and increment MOVF TABLAT, W ; get data MOVWF WORD_EVEN TBLRD*+ ; read into TABLAT and increment MOVFW TABLAT, W ; get data MOVF WORD_ODDPIC18F2420/2520/4420/4520 DS39631E-page 78 © 2008 Microchip Technology Inc. 6.4 Erasing Flash Program Memory The minimum erase block is 32 words or 64 bytes. Only through the use of an external programmer, or through ICSP control, can larger blocks of program memory be bulk erased. Word erase in the Flash array is not supported. When initiating an erase sequence from the microcontroller itself, a block of 64 bytes of program memory is erased. The Most Significant 16 bits of the TBLPTR<21:6> point to the block being erased. TBLPTR<5:0> are ignored. The EECON1 register commands the erase operation. The EEPGD bit must be set to point to the Flash program memory. The WREN bit must be set to enable write operations. The FREE bit is set to select an erase operation. For protection, the write initiate sequence for EECON2 must be used. A long write is necessary for erasing the internal Flash. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. 6.4.1 FLASH PROGRAM MEMORY ERASE SEQUENCE The sequence of events for erasing a block of internal program memory location is: 1. Load Table Pointer register with address of row being erased. 2. Set the EECON1 register for the erase operation: • set EEPGD bit to point to program memory; • clear the CFGS bit to access program memory; • set WREN bit to enable writes; • set FREE bit to enable the erase. 3. Disable interrupts. 4. Write 55h to EECON2. 5. Write 0AAh to EECON2. 6. Set the WR bit. This will begin the row erase cycle. 7. The CPU will stall for duration of the erase (about 2 ms using internal timer). 8. Re-enable interrupts. EXAMPLE 6-2: ERASING A FLASH PROGRAM MEMORY ROW MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL ERASE_ROW BSF EECON1, EEPGD ; point to Flash program memory BCF EECON1, CFGS ; access Flash program memory BSF EECON1, WREN ; enable write to memory BSF EECON1, FREE ; enable Row Erase operation BCF INTCON, GIE ; disable interrupts Required MOVLW 55h Sequence MOVWF EECON2 ; write 55h MOVLW 0AAh MOVWF EECON2 ; write 0AAh BSF EECON1, WR ; start erase (CPU stall) BSF INTCON, GIE ; re-enable interrupts© 2008 Microchip Technology Inc. DS39631E-page 79 PIC18F2420/2520/4420/4520 6.5 Writing to Flash Program Memory The minimum programming block is 16 words or 32 bytes. Word or byte programming is not supported. Table writes are used internally to load the holding registers needed to program the Flash memory. There are 32 holding registers used by the table writes for programming. Since the Table Latch (TABLAT) is only a single byte, the TBLWT instruction may need to be executed 32 times for each programming operation. All of the table write operations will essentially be short writes because only the holding registers are written. At the end of updating the 32 holding registers, the EECON1 register must be written to in order to start the programming operation with a long write. The long write is necessary for programming the internal Flash. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. The EEPROM on-chip timer controls the write time. The write/erase voltages are generated by an on-chip charge pump, rated to operate over the voltage range of the device. FIGURE 6-5: TABLE WRITES TO FLASH PROGRAM MEMORY 6.5.1 FLASH PROGRAM MEMORY WRITE SEQUENCE The sequence of events for programming an internal program memory location should be: 1. Read 64 bytes into RAM. 2. Update data values in RAM as necessary. 3. Load Table Pointer register with address being erased. 4. Execute the row erase procedure. 5. Load Table Pointer register with address of first byte being written. 6. Write the 32 bytes into the holding registers with auto-increment. 7. Set the EECON1 register for the write operation: • set EEPGD bit to point to program memory; • clear the CFGS bit to access program memory; • set WREN to enable byte writes. 8. Disable interrupts. 9. Write 55h to EECON2. 10. Write 0AAh to EECON2. 11. Set the WR bit. This will begin the write cycle. 12. The CPU will stall for duration of the write (about 2 ms using internal timer). 13. Re-enable interrupts. 14. Verify the memory (table read). This procedure will require about 6 ms to update one row of 64 bytes of memory. An example of the required code is given in Example 6-3. Note: The default value of the holding registers on device Resets and after write operations is FFh. A write of FFh to a holding register does not modify that byte. This means individual bytes of program memory may be modified, provided that the change does not attempt to change any bit from a ‘0’ to a ‘1’. When modifying individual bytes, it is not necessary to load all 32 holding registers before executing a write operation. TABLAT TBLPTR = xxxxx0 TBLPTR = xxxxx1 TBLPTR = xxxx3F Write Register TBLPTR = xxxxx2 Program Memory Holding Register Holding Register Holding Register Holding Register 8 8 8 8 Note: Before setting the WR bit, the Table Pointer address needs to be within the intended address range of the 32 bytes in the holding register.PIC18F2420/2520/4420/4520 DS39631E-page 80 © 2008 Microchip Technology Inc. EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY MOVLW D'64 ; number of bytes in erase block MOVWF COUNTER MOVLW BUFFER_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL READ_BLOCK TBLRD*+ ; read into TABLAT, and inc MOVF TABLAT, W ; get data MOVWF POSTINC0 ; store data DECFSZ COUNTER ; done? BRA READ_BLOCK ; repeat MODIFY_WORD MOVLW DATA_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW DATA_ADDR_LOW MOVWF FSR0L MOVLW NEW_DATA_LOW ; update buffer word MOVWF POSTINC0 MOVLW NEW_DATA_HIGH MOVWF INDF0 ERASE_BLOCK MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL BSF EECON1, EEPGD ; point to Flash program memory BCF EECON1, CFGS ; access Flash program memory BSF EECON1, WREN ; enable write to memory BSF EECON1, FREE ; enable Row Erase operation BCF INTCON, GIE ; disable interrupts MOVLW 55h Required MOVWF EECON2 ; write 55h Sequence MOVLW 0AAh MOVWF EECON2 ; write 0AAh BSF EECON1, WR ; start erase (CPU stall) BSF INTCON, GIE ; re-enable interrupts TBLRD*- ; dummy read decrement MOVLW BUFFER_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L WRITE_BUFFER_BACK MOVLW D’32 ; number of bytes in holding register MOVWF COUNTER WRITE_BYTE_TO_HREGS MOVFF POSTINC0, WREG ; get low byte of buffer data MOVWF TABLAT ; present data to table latch TBLWT+* ; write data, perform a short write ; to internal TBLWT holding register. DECFSZ COUNTER ; loop until buffers are full BRA WRITE_WORD_TO_HREGS© 2008 Microchip Technology Inc. DS39631E-page 81 PIC18F2420/2520/4420/4520 EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED) 6.5.2 WRITE VERIFY Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 6.5.3 UNEXPECTED TERMINATION OF WRITE OPERATION If a write is terminated by an unplanned event, such as loss of power or an unexpected Reset, the memory location just programmed should be verified and reprogrammed if needed. If the write operation is interrupted by a MCLR Reset or a WDT Time-out Reset during normal operation, the user can check the WRERR bit and rewrite the location(s) as needed. 6.5.4 PROTECTION AGAINST SPURIOUS WRITES To protect against spurious writes to Flash program memory, the write initiate sequence must also be followed. See Section 23.0 “Special Features of the CPU” for more detail. 6.6 Flash Program Operation During Code Protection See Section 23.5 “Program Verification and Code Protection” for details on code protection of Flash program memory. TABLE 6-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY PROGRAM_MEMORY BSF EECON1, EEPGD ; point to Flash program memory BCF EECON1, CFGS ; access Flash program memory BSF EECON1, WREN ; enable write to memory BCF INTCON, GIE ; disable interrupts MOVLW 55h Required MOVWF EECON2 ; write 55h Sequence MOVLW 0AAh MOVWF EECON2 ; write 0AAh BSF EECON1, WR ; start program (CPU stall) BSF INTCON, GIE ; re-enable interrupts BCF EECON1, WREN ; disable write to memory Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TBLPTRU — — bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) 49 TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 49 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 49 TABLAT Program Memory Table Latch 49 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 EECON2 EEPROM Control Register 2 (not a physical register) 51 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD 51 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.PIC18F2420/2520/4420/4520 DS39631E-page 82 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 83 PIC18F2420/2520/4420/4520 7.0 DATA EEPROM MEMORY The data EEPROM is a nonvolatile memory array, separate from the data RAM and program memory, that is used for long-term storage of program data. It is not directly mapped in either the register file or program memory space but is indirectly addressed through the Special Function Registers (SFRs). The EEPROM is readable and writable during normal operation over the entire VDD range. Five SFRs are used to read and write to the data EEPROM as well as the program memory. They are: • EECON1 • EECON2 • EEDATA • EEADR The data EEPROM allows byte read and write. When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and the EEADR register holds the address of the EEPROM location being accessed. The EEPROM data memory is rated for high erase/write cycle endurance. A byte write automatically erases the location and writes the new data (erase-before-write). The write time is controlled by an on-chip timer; it will vary with voltage and temperature as well as from chip to chip. Please refer to parameter D122 (Table 26-1 in Section 26.0 “Electrical Characteristics”) for exact limits. 7.1 EEADR Register The EEADR register is used to address the data EEPROM for read and write operations. The 8-bit range of the register can address a memory range of 256 bytes (00h to FFh). 7.2 EECON1 and EECON2 Registers Access to the data EEPROM is controlled by two registers: EECON1 and EECON2. These are the same registers which control access to the program memory and are used in a similar manner for the data EEPROM. The EECON1 register (Register 7-1) is the control register for data and program memory access. Control bit EEPGD determines if the access will be to program or data EEPROM memory. When clear, operations will access the data EEPROM memory. When set, program memory is accessed. Control bit, CFGS, determines if the access will be to the Configuration registers or to program memory/data EEPROM memory. When set, subsequent operations access Configuration registers. When CFGS is clear, the EEPGD bit selects either program Flash or data EEPROM memory. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set in hardware when the WR bit is set and cleared when the internal programming timer expires and the write operation is complete. The WR control bit initiates write operations. The bit can be set but not cleared in software. It is only cleared in hardware at the completion of the write operation. Control bits, RD and WR, start read and erase/write operations, respectively. These bits are set by firmware and cleared by hardware at the completion of the operation. The RD bit cannot be set when accessing program memory (EEPGD = 1). Program memory is read using table read instructions. See Section 6.1 “Table Reads and Table Writes” regarding table reads. The EECON2 register is not a physical register. It is used exclusively in the memory write and erase sequences. Reading EECON2 will read all ‘0’s. Note: During normal operation, the WRERR may read as ‘1’. This can indicate that a write operation was prematurely terminated by a Reset, or a write operation was attempted improperly. Note: The EEIF interrupt flag bit (PIR2<4>) is set when the write is complete. It must be cleared in software.PIC18F2420/2520/4420/4520 DS39631E-page 84 © 2008 Microchip Technology Inc. REGISTER 7-1: EECON1: EEPROM CONTROL REGISTER 1 R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD CFGS — FREE WRERR(1) WREN WR RD bit 7 bit 0 Legend: S = Settable bit (cannot be cleared in software) R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 EEPGD: Flash Program or Data EEPROM Memory Select bit 1 = Access Flash program memory 0 = Access data EEPROM memory bit 6 CFGS: Flash Program/Data EEPROM or Configuration Select bit 1 = Access Configuration registers 0 = Access Flash program or data EEPROM memory bit 5 Unimplemented: Read as ‘0’ bit 4 FREE: Flash Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only bit 3 WRERR: Flash Program/Data EEPROM Error Flag bit(1) 1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal operation, or an improper write attempt) 0 = The write operation completed bit 2 WREN: Flash Program/Data EEPROM Write Enable bit 1 = Allows write cycles to Flash program/data EEPROM 0 = Inhibits write cycles to Flash program/data EEPROM bit 1 WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle (The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete bit 0 RD: Read Control bit 1 = Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1 or CFGS = 1.) 0 = Does not initiate an EEPROM read Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition.© 2008 Microchip Technology Inc. DS39631E-page 85 PIC18F2420/2520/4420/4520 7.3 Reading the Data EEPROM Memory To read a data memory location, the user must write the address to the EEADR register, clear the EEPGD control bit (EECON1<7>) and then set control bit, RD (EECON1<0>). The data is available on the very next instruction cycle; therefore, the EEDATA register can be read by the next instruction. EEDATA will hold this value until another read operation, or until it is written to by the user (during a write operation). The basic process is shown in Example 7-1. 7.4 Writing to the Data EEPROM Memory To write an EEPROM data location, the address must first be written to the EEADR register and the data written to the EEDATA register. The sequence in Example 7-2 must be followed to initiate the write cycle. The write will not begin if this sequence is not exactly followed (write 55h to EECON2, write 0AAh to EECON2, then set WR bit) for each byte. It is strongly recommended that interrupts be disabled during this code segment. Additionally, the WREN bit in EECON1 must be set to enable writes. This mechanism prevents accidental writes to data EEPROM due to unexpected code execution (i.e., runaway programs). The WREN bit should be kept clear at all times, except when updating the EEPROM. The WREN bit is not cleared by hardware. After a write sequence has been initiated, EECON1, EEADR and EEDATA cannot be modified. The WR bit will be inhibited from being set unless the WREN bit is set. Both WR and WREN cannot be set with the same instruction. At the completion of the write cycle, the WR bit is cleared in hardware and the EEPROM Interrupt Flag bit, EEIF, is set. The user may either enable this interrupt or poll this bit. EEIF must be cleared by software. 7.5 Write Verify Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. EXAMPLE 7-1: DATA EEPROM READ EXAMPLE 7-2: DATA EEPROM WRITE MOVLW DATA_EE_ADDR ; MOVWF EEADR ; Data Memory Address to read BCF EECON1, EEPGD ; Point to DATA memory BCF EECON1, CFGS ; Access EEPROM BSF EECON1, RD ; EEPROM Read MOVF EEDATA, W ; W = EEDATA MOVLW DATA_EE_ADDR ; MOVWF EEADR ; Data Memory Address to write MOVLW DATA_EE_DATA ; MOVWF EEDATA ; Data Memory Value to write BCF EECON1, EEPGD ; Point to DATA memory BCF EECON1, CFGS ; Access EEPROM BSF EECON1, WREN ; Enable writes BCF INTCON, GIE ; Disable Interrupts MOVLW 55h ; Required MOVWF EECON2 ; Write 55h Sequence MOVLW 0AAh ; MOVWF EECON2 ; Write 0AAh BSF EECON1, WR ; Set WR bit to begin write BSF INTCON, GIE ; Enable Interrupts ; User code execution BCF EECON1, WREN ; Disable writes on write complete (EEIF set)PIC18F2420/2520/4420/4520 DS39631E-page 86 © 2008 Microchip Technology Inc. 7.6 Operation During Code-Protect Data EEPROM memory has its own code-protect bits in Configuration Words. External read and write operations are disabled if code protection is enabled. The microcontroller itself can both read and write to the internal data EEPROM, regardless of the state of the code-protect Configuration bit. Refer to Section 23.0 “Special Features of the CPU” for additional information. 7.7 Protection Against Spurious Write There are conditions when the user may not want to write to the data EEPROM memory. To protect against spurious EEPROM writes, various mechanisms have been implemented. On power-up, the WREN bit is cleared. In addition, writes to the EEPROM are blocked during the Power-up Timer period (TPWRT, parameter 33). The write initiate sequence and the WREN bit together help prevent an accidental write during brown-out, power glitch or software malfunction. 7.8 Using the Data EEPROM The data EEPROM is a high-endurance, byte addressable array that has been optimized for the storage of frequently changing information (e.g., program variables or other data that are updated often). Frequently changing values will typically be updated more often than specification D124. If this is not the case, an array refresh must be performed. For this reason, variables that change infrequently (such as constants, IDs, calibration, etc.) should be stored in Flash program memory. A simple data EEPROM refresh routine is shown in Example 7-3. EXAMPLE 7-3: DATA EEPROM REFRESH ROUTINE Note: If data EEPROM is only used to store constants and/or data that changes rarely, an array refresh is likely not required. See specification D124. CLRF EEADR ; Start at address 0 BCF EECON1, CFGS ; Set for memory BCF EECON1, EEPGD ; Set for Data EEPROM BCF INTCON, GIE ; Disable interrupts BSF EECON1, WREN ; Enable writes Loop ; Loop to refresh array BSF EECON1, RD ; Read current address MOVLW 55h ; MOVWF EECON2 ; Write 55h MOVLW 0AAh ; MOVWF EECON2 ; Write 0AAh BSF EECON1, WR ; Set WR bit to begin write BTFSC EECON1, WR ; Wait for write to complete BRA $-2 INCFSZ EEADR, F ; Increment address BRA LOOP ; Not zero, do it again BCF EECON1, WREN ; Disable writes BSF INTCON, GIE ; Enable interrupts© 2008 Microchip Technology Inc. DS39631E-page 87 PIC18F2420/2520/4420/4520 TABLE 7-1: REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 EEADR EEPROM Address Register 51 EEDATA EEPROM Data Register 51 EECON2 EEPROM Control Register 2 (not a physical register) 51 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD 51 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.PIC18F2420/2520/4420/4520 DS39631E-page 88 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 89 PIC18F2420/2520/4420/4520 8.0 8 x 8 HARDWARE MULTIPLIER 8.1 Introduction All PIC18 devices include an 8 x 8 hardware multiplier as part of the ALU. The multiplier performs an unsigned operation and yields a 16-bit result that is stored in the product register pair, PRODH:PRODL. The multiplier’s operation does not affect any flags in the STATUS register. Making multiplication a hardware operation allows it to be completed in a single instruction cycle. This has the advantages of higher computational throughput and reduced code size for multiplication algorithms and allows the PIC18 devices to be used in many applications previously reserved for digital signal processors. A comparison of various hardware and software multiply operations, along with the savings in memory and execution time, is shown in Table 8-1. 8.2 Operation Example 8-1 shows the instruction sequence for an 8 x 8 unsigned multiplication. Only one instruction is required when one of the arguments is already loaded in the WREG register. Example 8-2 shows the sequence to do an 8 x 8 signed multiplication. To account for the sign bits of the arguments, each argument’s Most Significant bit (MSb) is tested and the appropriate subtractions are done. EXAMPLE 8-1: 8 x 8 UNSIGNED MULTIPLY ROUTINE EXAMPLE 8-2: 8 x 8 SIGNED MULTIPLY ROUTINE TABLE 8-1: PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS MOVF ARG1, W ; MULWF ARG2 ; ARG1 * ARG2 -> ; PRODH:PRODL MOVF ARG1, W MULWF ARG2 ; ARG1 * ARG2 -> ; PRODH:PRODL BTFSC ARG2, SB ; Test Sign Bit SUBWF PRODH, F ; PRODH = PRODH ; - ARG1 MOVF ARG2, W BTFSC ARG1, SB ; Test Sign Bit SUBWF PRODH, F ; PRODH = PRODH ; - ARG2 Routine Multiply Method Program Memory (Words) Cycles (Max) Time @ 40 MHz @ 10 MHz @ 4 MHz 8 x 8 unsigned Without hardware multiply 13 69 6.9 μs 27.6 μs 69 μs Hardware multiply 1 1 100 ns 400 ns 1 μs 8 x 8 signed Without hardware multiply 33 91 9.1 μs 36.4 μs 91 μs Hardware multiply 6 6 600 ns 2.4 μs 6 μs 16 x 16 unsigned Without hardware multiply 21 242 24.2 μs 96.8 μs 242 μs Hardware multiply 28 28 2.8 μs 11.2 μs 28 μs 16 x 16 signed Without hardware multiply 52 254 25.4 μs 102.6 μs 254 μs Hardware multiply 35 40 4.0 μs 16.0 μs 40 μsPIC18F2420/2520/4420/4520 DS39631E-page 90 © 2008 Microchip Technology Inc. Example 8-3 shows the sequence to do a 16 x 16 unsigned multiplication. Equation 8-1 shows the algorithm that is used. The 32-bit result is stored in four registers (RES<3:0>). EQUATION 8-1: 16 x 16 UNSIGNED MULTIPLICATION ALGORITHM EXAMPLE 8-3: 16 x 16 UNSIGNED MULTIPLY ROUTINE Example 8-4 shows the sequence to do a 16 x 16 signed multiply. Equation 8-2 shows the algorithm used. The 32-bit result is stored in four registers (RES<3:0>). To account for the sign bits of the arguments, the MSb for each argument pair is tested and the appropriate subtractions are done. EQUATION 8-2: 16 x 16 SIGNED MULTIPLICATION ALGORITHM EXAMPLE 8-4: 16 x 16 SIGNED MULTIPLY ROUTINE RES<3:0> = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28) + (ARG1L • ARG2H • 28) + (ARG1L • ARG2L) MOVF ARG1L, W MULWF ARG2L ; ARG1L * ARG2L-> ; PRODH:PRODL MOVFF PRODH, RES1 ; MOVFF PRODL, RES0 ; ; MOVF ARG1H, W MULWF ARG2H ; ARG1H * ARG2H-> ; PRODH:PRODL MOVFF PRODH, RES3 ; MOVFF PRODL, RES2 ; ; MOVF ARG1L, W MULWF ARG2H ; ARG1L * ARG2H-> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; MOVF ARG1H, W ; MULWF ARG2L ; ARG1H * ARG2L-> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; RES<3:0> = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28) + (ARG1L • ARG2H • 28) + (ARG1L • ARG2L) + (-1 • ARG2H<7> • ARG1H:ARG1L • 216) + (-1 • ARG1H<7> • ARG2H:ARG2L • 216) MOVF ARG1L, W MULWF ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL MOVFF PRODH, RES1 ; MOVFF PRODL, RES0 ; ; MOVF ARG1H, W MULWF ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL MOVFF PRODH, RES3 ; MOVFF PRODL, RES2 ; ; MOVF ARG1L, W MULWF ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; MOVF ARG1H, W ; MULWF ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; BTFSS ARG2H, 7 ; ARG2H:ARG2L neg? BRA SIGN_ARG1 ; no, check ARG1 MOVF ARG1L, W ; SUBWF RES2 ; MOVF ARG1H, W ; SUBWFB RES3 ; SIGN_ARG1 BTFSS ARG1H, 7 ; ARG1H:ARG1L neg? BRA CONT_CODE ; no, done MOVF ARG2L, W ; SUBWF RES2 ; MOVF ARG2H, W ; SUBWFB RES3 ; CONT_CODE :© 2008 Microchip Technology Inc. DS39631E-page 91 PIC18F2420/2520/4420/4520 9.0 INTERRUPTS The PIC18F2420/2520/4420/4520 devices have multiple interrupt sources and an interrupt priority feature that allows most interrupt sources to be assigned a high-priority level or a low-priority level. The high-priority interrupt vector is at 0008h and the lowpriority interrupt vector is at 0018h. High-priority interrupt events will interrupt any low-priority interrupts that may be in progress. There are ten registers which are used to control interrupt operation. These registers are: • RCON • INTCON • INTCON2 • INTCON3 • PIR1, PIR2 • PIE1, PIE2 • IPR1, IPR2 It is recommended that the Microchip header files supplied with MPLAB® IDE be used for the symbolic bit names in these registers. This allows the assembler/ compiler to automatically take care of the placement of these bits within the specified register. In general, interrupt sources have three bits to control their operation. They are: • Flag bit to indicate that an interrupt event occurred • Enable bit that allows program execution to branch to the interrupt vector address when the flag bit is set • Priority bit to select high priority or low priority The interrupt priority feature is enabled by setting the IPEN bit (RCON<7>). When interrupt priority is enabled, there are two bits which enable interrupts globally. Setting the GIEH bit (INTCON<7>) enables all interrupts that have the priority bit set (high priority). Setting the GIEL bit (INTCON<6>) enables all interrupts that have the priority bit cleared (low priority). When the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address 0008h or 0018h, depending on the priority bit setting. Individual interrupts can be disabled through their corresponding enable bits. When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PIC® mid-range devices. In Compatibility mode, the interrupt priority bits for each source have no effect. INTCON<6> is the PEIE bit, which enables/disables all peripheral interrupt sources. INTCON<7> is the GIE bit, which enables/disables all interrupt sources. All interrupts branch to address 0008h in Compatibility mode. When an interrupt is responded to, the global interrupt enable bit is cleared to disable further interrupts. If the IPEN bit is cleared, this is the GIE bit. If interrupt priority levels are used, this will be either the GIEH or GIEL bit. High-priority interrupt sources can interrupt a lowpriority interrupt. Low-priority interrupts are not processed while high-priority interrupts are in progress. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (0008h or 0018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bits must be cleared in software before re-enabling interrupts to avoid recursive interrupts. The “return from interrupt” instruction, RETFIE, exits the interrupt routine and sets the GIE bit (GIEH or GIEL if priority levels are used), which re-enables interrupts. For external interrupt events, such as the INTx pins or the PORTB input change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding enable bit or the GIE bit. Note: Do not use the MOVFF instruction to modify any of the interrupt control registers while any interrupt is enabled. Doing so may cause erratic microcontroller behavior.PIC18F2420/2520/4420/4520 DS39631E-page 92 © 2008 Microchip Technology Inc. FIGURE 9-1: PIC18 INTERRUPT LOGIC TMR0IE GIE/GIEH PEIE/GIEL Wake-up if in Interrupt to CPU Vector to Location 0008h INT2IF INT2IE INT2IP INT1IF INT1IE INT1IP TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP IPEN TMR0IF TMR0IP INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP RBIF RBIE RBIP INT0IF INT0IE PEIE/GIE Interrupt to CPU Vector to Location IPEN IPEN 0018h SSPIF SSPIE SSPIP SSPIF SSPIE SSPIP ADIF ADIE ADIP RCIF RCIE RCIP Additional Peripheral Interrupts ADIF ADIE ADIP High-Priority Interrupt Generation Low-Priority Interrupt Generation RCIF RCIE RCIP Additional Peripheral Interrupts Idle or Sleep modes GIE/GIEH© 2008 Microchip Technology Inc. DS39631E-page 93 PIC18F2420/2520/4420/4520 9.1 INTCON Registers The INTCON registers are readable and writable registers, which contain various enable, priority and flag bits. Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. REGISTER 9-1: INTCON: INTERRUPT CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts When IPEN = 1: 1 = Enables all high-priority interrupts 0 = Disables all interrupts bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts When IPEN = 1: 1 = Enables all low-priority peripheral interrupts 0 = Disables all low-priority peripheral interrupts bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 overflow interrupt 0 = Disables the TMR0 overflow interrupt bit 4 INT0IE: INT0 External Interrupt Enable bit 1 = Enables the INT0 external interrupt 0 = Disables the INT0 external interrupt bit 3 RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow bit 1 INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared in software) 0 = The INT0 external interrupt did not occur bit 0 RBIF: RB Port Change Interrupt Flag bit(1) 1 = At least one of the RB<7:4> pins changed state (must be cleared in software) 0 = None of the RB<7:4> pins have changed state Note 1: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared. PIC18F2420/2520/4420/4520 DS39631E-page 94 © 2008 Microchip Technology Inc. REGISTER 9-2: INTCON2: INTERRUPT CONTROL REGISTER 2 R/W-1 R/W-1 R/W-1 R/W-1 U-0 R/W-1 U-0 R/W-1 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 RBPU: PORTB Pull-up Enable bit 1 = All PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values bit 6 INTEDG0: External Interrupt 0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 5 INTEDG1: External Interrupt 1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 4 INTEDG2: External Interrupt 2 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 3 Unimplemented: Read as ‘0’ bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 Unimplemented: Read as ‘0’ bit 0 RBIP: RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.© 2008 Microchip Technology Inc. DS39631E-page 95 PIC18F2420/2520/4420/4520 REGISTER 9-3: INTCON3: INTERRUPT CONTROL REGISTER 3 R/W-1 R/W-1 U-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 INT2IP: INT2 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 INT1IP: INT1 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 Unimplemented: Read as ‘0’ bit 4 INT2IE: INT2 External Interrupt Enable bit 1 = Enables the INT2 external interrupt 0 = Disables the INT2 external interrupt bit 3 INT1IE: INT1 External Interrupt Enable bit 1 = Enables the INT1 external interrupt 0 = Disables the INT1 external interrupt bit 2 Unimplemented: Read as ‘0’ bit 1 INT2IF: INT2 External Interrupt Flag bit 1 = The INT2 external interrupt occurred (must be cleared in software) 0 = The INT2 external interrupt did not occur bit 0 INT1IF: INT1 External Interrupt Flag bit 1 = The INT1 external interrupt occurred (must be cleared in software) 0 = The INT1 external interrupt did not occur Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.PIC18F2420/2520/4420/4520 DS39631E-page 96 © 2008 Microchip Technology Inc. 9.2 PIR Registers The PIR registers contain the individual flag bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Request Flag registers (PIR1 and PIR2). Note 1: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the Global Interrupt Enable bit, GIE (INTCON<7>). 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt and after servicing that interrupt. REGISTER 9-4: PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1 R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 PSPIF: Parallel Slave Port Read/Write Interrupt Flag bit(1) 1 = A read or a write operation has taken place (must be cleared in software) 0 = No read or write has occurred bit 6 ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete bit 5 RCIF: EUSART Receive Interrupt Flag bit 1 = The EUSART receive buffer, RCREG, is full (cleared when RCREG is read) 0 = The EUSART receive buffer is empty bit 4 TXIF: EUSART Transmit Interrupt Flag bit 1 = The EUSART transmit buffer, TXREG, is empty (cleared when TXREG is written) 0 = The EUSART transmit buffer is full bit 3 SSPIF: Master Synchronous Serial Port Interrupt Flag bit 1 = The transmission/reception is complete (must be cleared in software) 0 = Waiting to transmit/receive bit 2 CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode. bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = TMR1 register did not overflow Note 1: This bit is unimplemented on 28-pin devices and will read as ‘0’.© 2008 Microchip Technology Inc. DS39631E-page 97 PIC18F2420/2520/4420/4520 REGISTER 9-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit 1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software) 0 = Device clock operating bit 6 CMIF: Comparator Interrupt Flag bit 1 = Comparator input has changed (must be cleared in software) 0 = Comparator input has not changed bit 5 Unimplemented: Read as ‘0’ bit 4 EEIF: Data EEPROM/Flash Write Operation Interrupt Flag bit 1 = The write operation is complete (must be cleared in software) 0 = The write operation is not complete or has not been started bit 3 BCLIF: Bus Collision Interrupt Flag bit 1 = A bus collision occurred (must be cleared in software) 0 = No bus collision occurred bit 2 HLVDIF: High/Low-Voltage Detect Interrupt Flag bit 1 = A high/low-voltage condition occurred (direction determined by VDIRMAG bit, HLVDCON<7>) 0 = A high/low-voltage condition has not occurred bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared in software) 0 = TMR3 register did not overflow bit 0 CCP2IF: CCP2 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode. PIC18F2420/2520/4420/4520 DS39631E-page 98 © 2008 Microchip Technology Inc. 9.3 PIE Registers The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Enable registers (PIE1 and PIE2). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts. REGISTER 9-6: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 PSPIE: Parallel Slave Port Read/Write Interrupt Enable bit(1) 1 = Enables the PSP read/write interrupt 0 = Disables the PSP read/write interrupt bit 6 ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt bit 5 RCIE: EUSART Receive Interrupt Enable bit 1 = Enables the EUSART receive interrupt 0 = Disables the EUSART receive interrupt bit 4 TXIE: EUSART Transmit Interrupt Enable bit 1 = Enables the EUSART transmit interrupt 0 = Disables the EUSART transmit interrupt bit 3 SSPIE: Master Synchronous Serial Port Interrupt Enable bit 1 = Enables the MSSP interrupt 0 = Disables the MSSP interrupt bit 2 CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt Note 1: This bit is unimplemented on 28-pin devices and will read as ‘0’.© 2008 Microchip Technology Inc. DS39631E-page 99 PIC18F2420/2520/4420/4520 REGISTER 9-7: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit 1 = Enabled 0 = Disabled bit 6 CMIE: Comparator Interrupt Enable bit 1 = Enabled 0 = Disabled bit 5 Unimplemented: Read as ‘0’ bit 4 EEIE: Data EEPROM/Flash Write Operation Interrupt Enable bit 1 = Enabled 0 = Disabled bit 3 BCLIE: Bus Collision Interrupt Enable bit 1 = Enabled 0 = Disabled bit 2 HLVDIE: High/Low-Voltage Detect Interrupt Enable bit 1 = Enabled 0 = Disabled bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enabled 0 = Disabled bit 0 CCP2IE: CCP2 Interrupt Enable bit 1 = Enabled 0 = DisabledPIC18F2420/2520/4420/4520 DS39631E-page 100 © 2008 Microchip Technology Inc. 9.4 IPR Registers The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Priority registers (IPR1 and IPR2). Using the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set. REGISTER 9-8: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 PSPIP: Parallel Slave Port Read/Write Interrupt Priority bit(1) 1 = High priority 0 = Low priority bit 6 ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 RCIP: EUSART Receive Interrupt Priority bit 1 = High priority 0 = Low priority bit 4 TXIP: EUSART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 SSPIP: Master Synchronous Serial Port Interrupt Priority bit 1 = High priority 0 = Low priority bit 2 CCP1IP: CCP1 Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority Note 1: This bit is unimplemented on 28-pin devices and will read as ‘0’.© 2008 Microchip Technology Inc. DS39631E-page 101 PIC18F2420/2520/4420/4520 REGISTER 9-9: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2 R/W-1 R/W-1 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 CMIP: Comparator Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 Unimplemented: Read as ‘0’ bit 4 EEIP: Data EEPROM/Flash Write Operation Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 BCLIP: Bus Collision Interrupt Priority bit 1 = High priority 0 = Low priority bit 2 HLVDIP: High/Low-Voltage Detect Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 CCP2IP: CCP2 Interrupt Priority bit 1 = High priority 0 = Low priorityPIC18F2420/2520/4420/4520 DS39631E-page 102 © 2008 Microchip Technology Inc. 9.5 RCON Register The RCON register contains flag bits which are used to determine the cause of the last Reset or wake-up from Idle or Sleep modes. RCON also contains the IPEN bit which enables interrupt priorities. The operation of the SBOREN bit and the Reset flag bits is discussed in more detail in Section 4.1 “RCON Register”. REGISTER 9-10: RCON: RESET CONTROL REGISTER R/W-0 R/W-1(1) U-0 R/W-1 R-1 R-1 R/W-0(1) R/W-0 IPEN SBOREN — RI TO PD POR BOR bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) bit 6 SBOREN: Software BOR Enable bit(1) For details of bit operation, see Register 4-1. bit 5 Unimplemented: Read as ‘0’ bit 4 RI: RESET Instruction Flag bit For details of bit operation, see Register 4-1. bit 3 TO: Watchdog Timer Time-out Flag bit For details of bit operation, see Register 4-1. bit 2 PD: Power-Down Detection Flag bit For details of bit operation, see Register 4-1. bit 1 POR: Power-on Reset Status bit(1) For details of bit operation, see Register 4-1. bit 0 BOR: Brown-out Reset Status bit For details of bit operation, see Register 4-1. Note 1: Actual Reset values are determined by device configuration and the nature of the device Reset. See Register 4-1 for additional information.© 2008 Microchip Technology Inc. DS39631E-page 103 PIC18F2420/2520/4420/4520 9.6 INTx Pin Interrupts External interrupts on the RB0/INT0, RB1/INT1 and RB2/INT2 pins are edge-triggered. If the corresponding INTEDGx bit in the INTCON2 register is set (= 1), the interrupt is triggered by a rising edge; if the bit is clear, the trigger is on the falling edge. When a valid edge appears on the RBx/INTx pin, the corresponding flag bit, INTxIF, is set. This interrupt can be disabled by clearing the corresponding enable bit, INTxIE. Flag bit, INTxIF, must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1 and INT2) can wakeup the processor from Idle or Sleep modes if bit INTxIE was set prior to going into those modes. If the Global Interrupt Enable bit, GIE, is set, the processor will branch to the interrupt vector following wake-up. Interrupt priority for INT1 and INT2 is determined by the value contained in the Interrupt Priority bits, INT1IP (INTCON3<6>) and INT2IP (INTCON3<7>). There is no priority bit associated with INT0. It is always a high-priority interrupt source. 9.7 TMR0 Interrupt In 8-bit mode (which is the default), an overflow in the TMR0 register (FFh → 00h) will set flag bit, TMR0IF. In 16-bit mode, an overflow in the TMR0H:TMR0L register pair (FFFFh → 0000h) will set TMR0IF. The interrupt can be enabled/disabled by setting/clearing enable bit, TMR0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit, TMR0IP (INTCON2<2>). See Section 11.0 “Timer0 Module” for further details on the Timer0 module. 9.8 PORTB Interrupt-on-Change An input change on PORTB<7:4> sets flag bit, RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit, RBIE (INTCON<3>). Interrupt priority for PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RBIP (INTCON2<0>). 9.9 Context Saving During Interrupts During interrupts, the return PC address is saved on the stack. Additionally, the WREG, STATUS and BSR registers are saved on the Fast Return Stack. If a fast return from interrupt is not used (see Section 5.3 “Data Memory Organization”), the user may need to save the WREG, STATUS and BSR registers on entry to the Interrupt Service Routine. Depending on the user’s application, other registers may also need to be saved. Example 9-1 saves and restores the WREG, STATUS and BSR registers during an Interrupt Service Routine. EXAMPLE 9-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM MOVWF W_TEMP ; W_TEMP is in virtual bank MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere MOVFF BSR, BSR_TEMP ; BSR_TMEP located anywhere ; ; USER ISR CODE ; MOVFF BSR_TEMP, BSR ; Restore BSR MOVF W_TEMP, W ; Restore WREG MOVFF STATUS_TEMP, STATUS ; Restore STATUSPIC18F2420/2520/4420/4520 DS39631E-page 104 © 2008 Microchip Technology Inc. NOTES: © 2008 Microchip Technology Inc. DS39631E-page 105 PIC18F2420/2520/4420/4520 10.0 I/O PORTS Depending on the device selected and features enabled, there are up to five ports available. Some pins of the I/O ports are multiplexed with an alternate function from the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Each port has three registers for its operation. These registers are: • TRIS register (Data Direction register) • PORT register (reads the levels on the pins of the device) • LAT register (Data Latch register) The Data Latch (LAT register) is useful for read-modifywrite operations on the value that the I/O pins are driving. A simplified model of a generic I/O port, without the interfaces to other peripherals, is shown in Figure 10-1. FIGURE 10-1: GENERIC I/O PORT OPERATION 10.1 PORTA, TRISA and LATA Registers PORTA is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). Reading the PORTA register reads the status of the pins, whereas writing to it, will write to the port latch. The Data Latch (LATA) register is also memory mapped. Read-modify-write operations on the LATA register read and write the latched output value for PORTA. The RA4 pin is multiplexed with the Timer0 module clock input and one of the comparator outputs to become the RA4/T0CKI/C1OUT pin. Pins RA6 and RA7 are multiplexed with the main oscillator pins; they are enabled as oscillator or I/O pins by the selection of the main oscillator in the Configuration register (see Section 23.1 “Configuration Bits” for details). When they are not used as port pins, RA6 and RA7 and their associated TRIS and LAT bits are read as ‘0’. The other PORTA pins are multiplexed with analog inputs, the analog VREF+ and VREF- inputs and the comparator voltage reference output. The operation of pins RA<3:0> and RA5 as A/D Converter inputs is selected by clearing or setting the control bits in the ADCON1 register (A/D Control Register 1). Pins RA0 through RA5 may also be used as comparator inputs or outputs by setting the appropriate bits in the CMCON register. To use RA<3:0> as digital inputs, it is also necessary to turn off the comparators. The RA4/T0CKI/C1OUT pin is a Schmitt Trigger input. All other PORTA pins have TTL input levels and full CMOS output drivers. The TRISA register controls the direction of the PORTA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs. EXAMPLE 10-1: INITIALIZING PORTA Data Bus WR LAT WR TRIS RD Port Data Latch TRIS Latch RD TRIS Input Buffer I/O pin(1) D Q CK D Q CK EN Q D EN RD LAT or Port Note 1: I/O pins have diode protection to VDD and VSS. Note: On a Power-on Reset, RA5 and RA<3:0> are configured as analog inputs and read as ‘0’. RA4 is configured as a digital input. CLRF PORTA ; Initialize PORTA by ; clearing output ; data latches CLRF LATA ; Alternate method ; to clear output ; data latches MOVLW 07h ; Configure A/D MOVWF ADCON1 ; for digital inputs MOVWF 07h ; Configure comparators MOVWF CMCON ; for digital input MOVLW 0CFh ; Value used to ; initialize data ; direction MOVWF TRISA ; Set RA<3:0> as inputs ; RA<5:4> as outputsPIC18F2420/2520/4420/4520 DS39631E-page 106 © 2008 Microchip Technology Inc. TABLE 10-1: PORTA I/O SUMMARY Pin Function TRIS Setting I/O I/O Type Description RA0/AN0 RA0 0 O DIG LATA<0> data output; not affected by analog input. 1 I TTL PORTA<0> data input; disabled when analog input enabled. AN0 1 I ANA A/D input channel 0 and comparator C1- input. Default input configuration on POR; does not affect digital output. RA1/AN1 RA1 0 O DIG LATA<1> data output; not affected by analog input. 1 I TTL PORTA<1> data input; disabled when analog input enabled. AN1 1 I ANA A/D input channel 1 and comparator C2- input. Default input configuration on POR; does not affect digital output. RA2/AN2/ VREF-/CVREF RA2 0 O DIG LATA<2> data output; not affected by analog input. Disabled when CVREF output enabled. 1 I TTL PORTA<2> data input. Disabled when analog functions enabled; disabled when CVREF output enabled. AN2 1 I ANA A/D input channel 2 and comparator C2+ input. Default input configuration on POR; not affected by analog output. VREF- 1 I ANA A/D and comparator voltage reference low input. CVREF x O ANA Comparator voltage reference output. Enabling this feature disables digital I/O. RA3/AN3/VREF+ RA3 0 O DIG LATA<3> data output; not affected by analog input. 1 I TTL PORTA<3> data input; disabled when analog input enabled. AN3 1 I ANA A/D input channel 3 and comparator C1+ input. Default input configuration on POR. VREF+ 1 I ANA A/D and comparator voltage reference high input. RA4/T0CKI/C1OUT RA4 0 O DIG LATA<4> data output. 1 I ST PORTA<4> data input; default configuration on POR. T0CKI 1 I ST Timer0 clock input. C1OUT 0 O DIG Comparator 1 output; takes priority over port data. RA5/AN4/SS/ HLVDIN/C2OUT RA5 0 O DIG LATA<5> data output; not affected by analog input. 1 I TTL PORTA<5> data input; disabled when analog input enabled. AN4 1 I ANA A/D input channel 4. Default configuration on POR. SS 1 I TTL Slave select input for MSSP module. HLVDIN 1 I ANA High/Low-Voltage Detect external trip point input. C2OUT 0 O DIG Comparator 2 output; takes priority over port data. OSC2/CLKO/RA6 RA6 0 O DIG LATA<6> data output. Enabled in RCIO, INTIO2 and ECIO modes only. 1 I TTL PORTA<6> data input. Enabled in RCIO, INTIO2 and ECIO modes only. OSC2 x O ANA Main oscillator feedback output connection (XT, HS and LP modes). CLKO x O DIG System cycle clock output (FOSC/4) in RC, INTIO1 and EC Oscillator modes. OSC1/CLKI/RA7 RA7 0 O DIG LATA<7> data output. Disabled in external oscillator modes. 1 I TTL PORTA<7> data input. Disabled in external oscillator modes. OSC1 x I ANA Main oscillator input connection. CLKI x I ANA Main clock input connection. Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).© 2008 Microchip Technology Inc. DS39631E-page 107 PIC18F2420/2520/4420/4520 TABLE 10-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page PORTA RA7(1) RA6(1) RA5 RA4 RA3 RA2 RA1 RA0 52 LATA LATA7(1) LATA6(1) PORTA Data Latch Register (Read and Write to Data Latch) 52 TRISA TRISA7(1) TRISA6(1) PORTA Data Direction Register 52 ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 51 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 51 CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA. Note 1: RA<7:6> and their associated latch and data direction bits are enabled as I/O pins based on oscillator configuration; otherwise, they are read as ‘0’.PIC18F2420/2520/4420/4520 DS39631E-page 108 © 2008 Microchip Technology Inc. 10.2 PORTB, TRISB and LATB Registers PORTB is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATB) is also memory mapped. Read-modify-write operations on the LATB register read and write the latched output value for PORTB. EXAMPLE 10-2: INITIALIZING PORTB Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit, RBPU (INTCON2<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. Four of the PORTB pins (RB<7:4>) have an interrupton-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB<7:4> pin configured as an output is excluded from the interrupton-change comparison). The input pins (of RB<7:4>) are compared with the old value latched on the last read of PORTB. The “mismatch” outputs of RB<7:4> are ORed together to generate the RB Port Change Interrupt with Flag bit, RBIF (INTCON<0>). This interrupt can wake the device from the Sleep mode, or any of the Idle modes. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) Any read or write of PORTB (except with the MOVFF (ANY), PORTB instruction). b) Clear flag bit, RBIF. A mismatch condition will continue to set flag bit, RBIF. Reading PORTB will end the mismatch condition and allow flag bit, RBIF, to be cleared. The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. RB3 can be configured by the Configuration bit, CCP2MX, as the alternate peripheral pin for the CCP2 module (CCP2MX = 0). Note: On a Power-on Reset, RB<4:0> are configured as analog inputs by default and read as ‘0’; RB<7:5> are configured as digital inputs. By programming the Configuration bit, PBADEN, RB<4:0> will alternatively be configured as digital inputs on POR. CLRF PORTB ; Initialize PORTB by ; clearing output ; data latches CLRF LATB ; Alternate method ; to clear output ; data latches MOVLW 0Fh ; Set RB<4:0> as MOVWF ADCON1 ; digital I/O pins ; (required if config bit ; PBADEN is set) MOVLW 0CFh ; Value used to ; initialize data ; direction MOVWF TRISB ; Set RB<3:0> as inputs ; RB<5:4> as outputs ; RB<7:6> as inputs© 2008 Microchip Technology Inc. DS39631E-page 109 PIC18F2420/2520/4420/4520 TABLE 10-3: PORTB I/O SUMMARY Pin Function TRIS Setting I/O I/O Type Description RB0/INT0/FLT0/ AN12 RB0 0 O DIG LATB<0> data output; not affected by analog input. 1 I TTL PORTB<0> data input; weak pull-up when RBPU bit is cleared. Disabled when analog input enabled.(1) INT0 1 I ST External interrupt 0 input. FLT0 1 I ST Enhanced PWM Fault input (ECCP1 module); enabled in software. AN12 1 I ANA A/D input channel 12.(1) RB1/INT1/AN10 RB1 0 O DIG LATB<1> data output; not affected by analog input. 1 I TTL PORTB<1> data input; weak pull-up when RBPU bit is cleared. Disabled when analog input enabled.(1) INT1 1 I ST External Interrupt 1 input. AN10 1 I ANA A/D input channel 10.(1) RB2/INT2/AN8 RB2 0 O DIG LATB<2> data output; not affected by analog input. 1 I TTL PORTB<2> data input; weak pull-up when RBPU bit is cleared. Disabled when analog input enabled.(1) INT2 1 I ST External interrupt 2 input. AN8 1 I ANA A/D input channel 8.(1) RB3/AN9/CCP2 RB3 0 O DIG LATB<3> data output; not affected by analog input. 1 I TTL PORTB<3> data input; weak pull-up when RBPU bit is cleared. Disabled when analog input enabled.(1) AN9 1 I ANA A/D input channel 9.(1) CCP2(2) 0 O DIG CCP2 compare and PWM output. 1 I ST CCP2 capture input RB4/KBI0/AN11 RB4 0 O DIG LATB<4> data output; not affected by analog input. 1 I TTL PORTB<4> data input; weak pull-up when RBPU bit is cleared. Disabled when analog input enabled.(1) KBI0 1 I TTL Interrupt-on-pin change. AN11 1 I ANA A/D input channel 11.(1) RB5/KBI1/PGM RB5 0 O DIG LATB<5> data output. 1 I TTL PORTB<5> data input; weak pull-up when RBPU bit is cleared. KBI1 1 I TTL Interrupt-on-pin change. PGM x I ST Single-Supply In-Circuit Serial Programming™ mode entry (ICSP™). Enabled by LVP Configuration bit; all other pin functions disabled. RB6/KBI2/PGC RB6 0 O DIG LATB<6> data output. 1 I TTL PORTB<6> data input; weak pull-up when RBPU bit is cleared. KBI2 1 I TTL Interrupt-on-pin change. PGC x I ST Serial execution (ICSP) clock input for ICSP and ICD operation.(3) RB7/KBI3/PGD RB7 0 O DIG LATB<7> data output. 1 I TTL PORTB<7> data input; weak pull-up when RBPU bit is cleared. KBI3 1 I TTL Interrupt-on-pin change. PGD x O DIG Serial execution data output for ICSP and ICD operation.(3) x I ST Serial execution data input for ICSP and ICD operation.(3) Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). Note 1: Configuration on POR is determined by the PBADEN Configuration bit. Pins are configured as analog inputs by default when PBADEN is set and digital inputs when PBADEN is cleared. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is ‘0’. Default assignment is RC1. 3: All other pin functions are disabled when ICSP or ICD are enabled.PIC18F2420/2520/4420/4520 DS39631E-page 110 © 2008 Microchip Technology Inc. TABLE 10-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 52 LATB PORTB Data Latch Register (Read and Write to Data Latch) 52 TRISB PORTB Data Direction Register 52 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP 49 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 49 ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTB.© 2008 Microchip Technology Inc. DS39631E-page 111 PIC18F2420/2520/4420/4520 10.3 PORTC, TRISC and LATC Registers PORTC is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISC. Setting a TRISC bit (= 1) will make the corresponding PORTC pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATC) is also memory mapped. Read-modify-write operations on the LATC register read and write the latched output value for PORTC. PORTC is multiplexed with several peripheral functions (Table 10-5). The pins have Schmitt Trigger input buffers. RC1 is normally configured by Configuration bit, CCP2MX, as the default peripheral pin of the CCP2 module (default/erased state, CCP2MX = 1). When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for additional information. The contents of the TRISC register are affected by peripheral overrides. Reading TRISC always returns the current contents, even though a peripheral device may be overriding one or more of the pins. EXAMPLE 10-3: INITIALIZING PORTC Note: On a Power-on Reset, these pins are configured as digital inputs. CLRF PORTC ; Initialize PORTC by ; clearing output ; data latches CLRF LATC ; Alternate method ; to clear output ; data latches MOVLW 0CFh ; Value used to ; initialize data ; direction MOVWF TRISC ; Set RC<3:0> as inputs ; RC<5:4> as outputs ; RC<7:6> as inputsPIC18F2420/2520/4420/4520 DS39631E-page 112 © 2008 Microchip Technology Inc. TABLE 10-5: PORTC I/O SUMMARY Pin Function TRIS Setting I/O I/O Type Description RC0/T1OSO/ T13CKI RC0 0 O DIG LATC<0> data output. 1 I ST PORTC<0> data input. T1OSO x O ANA Timer1 oscillator output; enabled when Timer1 oscillator enabled. Disables digital I/O. T13CKI 1 I ST Timer1/Timer3 counter input. RC1/T1OSI/CCP2 RC1 0 O DIG LATC<1> data output. 1 I ST PORTC<1> data input. T1OSI x I ANA Timer1 oscillator input; enabled when Timer1 oscillator enabled. Disables digital I/O. CCP2(1) 0 O DIG CCP2 compare and PWM output; takes priority over port data. 1 I ST CCP2 capture input. RC2/CCP1/P1A RC2 0 O DIG LATC<2> data output. 1 I ST PORTC<2> data input. CCP1 0 O DIG ECCP1 compare or PWM output; takes priority over port data. 1 I ST ECCP1 capture input. P1A(2) 0 O DIG ECCP1 Enhanced PWM output, channel A. May be configured for tri-state during Enhanced PWM shutdown events. Takes priority over port data. RC3/SCK/SCL RC3 0 O DIG LATC<3> data output. 1 I ST PORTC<3> data input. SCK 0 O DIG SPI clock output (MSSP module); takes priority over port data. 1 I ST SPI clock input (MSSP module). SCL 0 O DIG I2C™ clock output (MSSP module); takes priority over port data. 1 I I2C/SMB I2C clock input (MSSP module); input type depends on module setting. RC4/SDI/SDA RC4 0 O DIG LATC<4> data output. 1 I ST PORTC<4> data input. SDI 1 I ST SPI data input (MSSP module). SDA 1 O DIG I2C data output (MSSP module); takes priority over port data. 1 I I2C/SMB I2C data input (MSSP module); input type depends on module setting. RC5/SDO RC5 0 O DIG LATC<5> data output. 1 I ST PORTC<5> data input. SDO 0 O DIG SPI data output (MSSP module); takes priority over port data. RC6/TX/CK RC6 0 O DIG LATC<6> data output. 1 I ST PORTC<6> data input. TX 1 O DIG Asynchronous serial transmit data output (EUSART module); takes priority over port data. User must configure as output. CK 1 O DIG Synchronous serial clock output (EUSART module); takes priority over port data. 1 I ST Synchronous serial clock input (EUSART module). RC7/RX/DT RC7 0 O DIG LATC<7> data output. 1 I ST PORTC<7> data input. RX 1 I ST Asynchronous serial receive data input (EUSART module). DT 1 O DIG Synchronous serial data output (EUSART module); takes priority over port data. 1 I ST Synchronous serial data input (EUSART module). User must configure as an input. Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; I 2C/SMB = I2C/SMBus input buffer; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. Alternate assignment is RB3. 2: Enhanced PWM output is available only on PIC18F4520 devices.© 2008 Microchip Technology Inc. DS39631E-page 113 PIC18F2420/2520/4420/4520 TABLE 10-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 52 LATC PORTC Data Latch Register (Read and Write to Data Latch) 52 TRISC PORTC Data Direction Register 52PIC18F2420/2520/4420/4520 DS39631E-page 114 © 2008 Microchip Technology Inc. 10.4 PORTD, TRISD and LATD Registers PORTD is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISD. Setting a TRISD bit (= 1) will make the corresponding PORTD pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISD bit (= 0) will make the corresponding PORTD pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATD) is also memory mapped. Read-modify-write operations on the LATD register read and write the latched output value for PORTD. All pins on PORTD are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Three of the PORTD pins are multiplexed with outputs P1B, P1C and P1D of the Enhanced CCP module. The operation of these additional PWM output pins is covered in greater detail in Section 16.0 “Enhanced Capture/Compare/PWM (ECCP) Module”. PORTD can also be configured as an 8-bit wide microprocessor port (Parallel Slave Port) by setting control bit, PSPMODE (TRISE<4>). In this mode, the input buffers are TTL. See Section 10.6 “Parallel Slave Port” for additional information on the Parallel Slave Port (PSP). EXAMPLE 10-4: INITIALIZING PORTD Note: PORTD is only available on 40/44-pin devices. Note: On a Power-on Reset, these pins are configured as digital inputs. Note: When the enhanced PWM mode is used with either dual or quad outputs, the PSP functions of PORTD are automatically disabled. CLRF PORTD ; Initialize PORTD by ; clearing output ; data latches CLRF LATD ; Alternate method ; to clear output ; data latches MOVLW 0CFh ; Value used to ; initialize data ; direction MOVWF TRISD ; Set RD<3:0> as inputs ; RD<5:4> as outputs ; RD<7:6> as inputs© 2008 Microchip Technology Inc. DS39631E-page 115 PIC18F2420/2520/4420/4520 TABLE 10-7: PORTD I/O SUMMARY Pin Function TRIS Setting I/O I/O Type Description RD0/PSP0 RD0 0 O DIG LATD<0> data output. 1 I ST PORTD<0> data input. PSP0 x O DIG PSP read data output (LATD<0>); takes priority over port data. x I TTL PSP write data input. RD1/PSP1 RD1 0 O DIG LATD<1> data output. 1 I ST PORTD<1> data input. PSP1 x O DIG PSP read data output (LATD<1>); takes priority over port data. x I TTL PSP write data input. RD2/PSP2 RD2 0 O DIG LATD<2> data output. 1 I ST PORTD<2> data input. PSP2 x O DIG PSP read data output (LATD<2>); takes priority over port data. x I TTL PSP write data input. RD3/PSP3 RD3 0 O DIG LATD<3> data output. 1 I ST PORTD<3> data input. PSP3 x O DIG PSP read data output (LATD<3>); takes priority over port data. x I TTL PSP write data input. RD4/PSP4 RD4 0 O DIG LATD<4> data output. 1 I ST PORTD<4> data input. PSP4 x O DIG PSP read data output (LATD<4>); takes priority over port data. x I TTL PSP write data input. RD5/PSP5/P1B RD5 0 O DIG LATD<5> data output. 1 I ST PORTD<5> data input. PSP5 x O DIG PSP read data output (LATD<5>); takes priority over port data. x I TTL PSP write data input. P1B 0 O DIG ECCP1 Enhanced PWM output, channel B; takes priority over port and PSP data. May be configured for tri-state during Enhanced PWM shutdown events. RD6/PSP6/P1C RD6 0 O DIG LATD<6> data output. 1 I ST PORTD<6> data input. PSP6 x O DIG PSP read data output (LATD<6>); takes priority over port data. x I TTL PSP write data input. P1C 0 O DIG ECCP1 Enhanced PWM output, channel C; takes priority over port and PSP data. May be configured for tri-state during Enhanced PWM shutdown events. RD7/PSP7/P1D RD7 0 O DIG LATD<7> data output. 1 I ST PORTD<7> data input. PSP7 x O DIG PSP read data output (LATD<7>); takes priority over port data. x I TTL PSP write data input. P1D 0 O DIG ECCP1 Enhanced PWM output, channel D; takes priority over port and PSP data. May be configured for tri-state during Enhanced PWM shutdown events. Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).PIC18F2420/2520/4420/4520 DS39631E-page 116 © 2008 Microchip Technology Inc. TABLE 10-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 52 LATD PORTD Data Latch Register (Read and Write to Data Latch) 52 TRISD PORTD Data Direction Register 52 TRISE(1) IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 52 CCP1CON P1M1(1) P1M0(1) DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTD. Note 1: These registers and/or bits are unimplemented on 28-oin devices.© 2008 Microchip Technology Inc. DS39631E-page 117 PIC18F2420/2520/4420/4520 10.5 PORTE, TRISE and LATE Registers Depending on the particular PIC18F2420/2520/4420/ 4520 device selected, PORTE is implemented in two different ways. For 40/44-pin devices, PORTE is a 4-bit wide port. Three pins (RE0/RD/AN5, RE1/WR/AN6 and RE2/CS/ AN7) are individually configurable as inputs or outputs. These pins have Schmitt Trigger input buffers. When selected as an analog input, these pins will read as ‘0’s. The corresponding Data Direction register is TRISE. Setting a TRISE bit (= 1) will make the corresponding PORTE pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISE bit (= 0) will make the corresponding PORTE pin an output (i.e., put the contents of the output latch on the selected pin). TRISE controls the direction of the RE pins, even when they are being used as analog inputs. The user must make sure to keep the pins configured as inputs when using them as analog inputs. The upper four bits of the TRISE register also control the operation of the Parallel Slave Port. Their operation is explained in Register 10-1. The Data Latch register (LATE) is also memory mapped. Read-modify-write operations on the LATE register, read and write the latched output value for PORTE. The fourth pin of PORTE (MCLR/VPP/RE3) is an input only pin. Its operation is controlled by the MCLRE Configuration bit. When selected as a port pin (MCLRE = 0), it functions as a digital input only pin; as such, it does not have TRIS or LAT bits associated with its operation. Otherwise, it functions as the device’s Master Clear input. In either configuration, RE3 also functions as the programming voltage input during programming. EXAMPLE 10-5: INITIALIZING PORTE 10.5.1 PORTE IN 28-PIN DEVICES For 28-pin devices, PORTE is only available when Master Clear functionality is disabled (MCLRE = 0). In these cases, PORTE is a single bit, input only port comprised of RE3 only. The pin operates as previously described. Note: On a Power-on Reset, RE<2:0> are configured as analog inputs. Note: On a Power-on Reset, RE3 is enabled as a digital input only if Master Clear functionality is disabled. CLRF PORTE ; Initialize PORTE by ; clearing output ; data latches CLRF LATE ; Alternate method ; to clear output ; data latches MOVLW 0Ah ; Configure A/D MOVWF ADCON1 ; for digital inputs MOVLW 03h ; Value used to ; initialize data ; direction MOVWF TRISE ; Set RE<0> as inputs ; RE<1> as outputs ; RE<2> as inputsPIC18F2420/2520/4420/4520 DS39631E-page 118 © 2008 Microchip Technology Inc. REGISTER 10-1: TRISE REGISTER (40/44-PIN DEVICES ONLY) R-0 R-0 R/W-0 R/W-0 U-0 R/W-1 R/W-1 R/W-1 IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 IBF: Input Buffer Full Status bit 1 = A word has been received and waiting to be read by the CPU 0 = No word has been received bit 6 OBF: Output Buffer Full Status bit 1 = The output buffer still holds a previously written word 0 = The output buffer has been read bit 5 IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode) 1 = A write occurred when a previously input word has not been read (must be cleared in software) 0 = No overflow occurred bit 4 PSPMODE: Parallel Slave Port Mode Select bit 1 = Parallel Slave Port mode 0 = General purpose I/O mode bit 3 Unimplemented: Read as ‘0’ bit 2 TRISE2: RE2 Direction Control bit 1 = Input 0 = Output bit 1 TRISE1: RE1 Direction Control bit 1 = Input 0 = Output bit 0 TRISE0: RE0 Direction Control bit 1 = Input 0 = Output© 2008 Microchip Technology Inc. DS39631E-page 119 PIC18F2420/2520/4420/4520 TABLE 10-9: PORTE I/O SUMMARY TABLE 10-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE Pin Function TRIS Setting I/O I/O Type Description RE0/RD/AN5 RE0 0 O DIG LATE<0> data output; not affected by analog input. 1 I ST PORTE<0> data input; disabled when analog input enabled. RD 1 I TTL PSP read enable input (PSP enabled). AN5 1 I ANA A/D input channel 5; default input configuration on POR. RE1/WR/AN6 RE1 0 O DIG LATE<1> data output; not affected by analog input. 1 I ST PORTE<1> data input; disabled when analog input enabled. WR 1 I TTL PSP write enable input (PSP enabled). AN6 1 I ANA A/D input channel 6; default input configuration on POR. RE2/CS/AN7 RE2 0 O DIG LATE<2> data output; not affected by analog input. 1 I ST PORTE<2> data input; disabled when analog input enabled. CS 1 I TTL PSP write enable input (PSP enabled). AN7 1 I ANA A/D input channel 7; default input configuration on POR. MCLR/VPP/RE3(1) MCLR — I ST External Master Clear input; enabled when MCLRE Configuration bit is set. VPP — I ANA High-voltage detection; used for ICSP™ mode entry detection. Always available regardless of pin mode. RE3 —(2) I ST PORTE<3> data input; enabled when MCLRE Configuration bit is clear. Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). Note 1: RE3 is available on both 28-pin and 40/44-pin devices. All other PORTE pins are only implemented on 40/44-pin devices. 2: RE3 does not have a corresponding TRIS bit to control data direction. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page PORTE — — — — RE3(1,2) RE2 RE1 RE0 52 LATE(2) — — — — — LATE Data Latch Register 52 TRISE IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 52 ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTE. Note 1: Implemented only when Master Clear functionality is disabled (MCLRE Configuration bit = 0). 2: RE3 is the only PORTE bit implemented on both 28-pin and 40/44-pin devices. All other bits are implemented only when PORTE is implemented (i.e., 40/44-pin devices).PIC18F2420/2520/4420/4520 DS39631E-page 120 © 2008 Microchip Technology Inc. 10.6 Parallel Slave Port In addition to its function as a general I/O port, PORTD can also operate as an 8-bit wide Parallel Slave Port (PSP) or microprocessor port. PSP operation is controlled by the 4 upper bits of the TRISE register (Register 10-1). Setting control bit, PSPMODE (TRISE<4>), enables PSP operation as long as the Enhanced CCP module is not operating in dual output or quad output PWM mode. In Slave mode, the port is asynchronously readable and writable by the external world. The PSP can directly interface to an 8-bit microprocessor data bus. The external microprocessor can read or write the PORTD latch as an 8-bit latch. Setting the control bit, PSPMODE, enables the PORTE I/O pins to become control inputs for the microprocessor port. When set, port pin RE0 is the RD input, RE1 is the WR input and RE2 is the CS (Chip Select) input. For this functionality, the corresponding data direction bits of the TRISE register (TRISE<2:0>) must be configured as inputs (set). The A/D port configuration bits, PFCG<3:0> (ADCON1<3:0>), must also be set to a value in the range of ‘1010’ through ‘1111’. A write to the PSP occurs when both the CS and WR lines are first detected low and ends when either are detected high. The PSPIF and IBF flag bits are both set when the write ends. A read from the PSP occurs when both the CS and RD lines are first detected low. The data in PORTD is read out and the OBF bit is clear. If the user writes new data to PORTD to set OBF, the data is immediately read out; however, the OBF bit is not set. When either the CS or RD lines are detected high, the PORTD pins return to the input state and the PSPIF bit is set. User applications should wait for PSPIF to be set before servicing the PSP; when this happens, the IBF and OBF bits can be polled and the appropriate action taken. The timing for the control signals in Write and Read modes is shown in Figure 10-3 and Figure 10-4, respectively. FIGURE 10-2: PORTD AND PORTE BLOCK DIAGRAM (PARALLEL SLAVE PORT) Note: The Parallel Slave Port is only available on 40/44-pin devices. Data Bus WR LATD RDx pin D Q CK EN Q D RD PORTD EN One bit of PORTD Set Interrupt Flag PSPIF (PIR1<7>) Read Chip Select Write RD CS WR TTL TTL TTL TTL or WR PORTD RD LATD Data Latch Note: I/O pins have diode protection to VDD and VSS. PORTE Pins© 2008 Microchip Technology Inc. DS39631E-page 121 PIC18F2420/2520/4420/4520 FIGURE 10-3: PARALLEL SLAVE PORT WRITE WAVEFORMS FIGURE 10-4: PARALLEL SLAVE PORT READ WAVEFORMS TABLE 10-11: REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 52 LATD PORTD Data Latch Register (Read and Write to Data Latch) 52 TRISD PORTD Data Direction Register 52 PORTE — — — — RE3 RE2 RE1 RE0 52 LATE — — — — — LATE Data Latch Register 52 TRISE IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 52 INTCON GIE/GIEH PEIE/GIEL TMR0IF INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Parallel Slave Port. Q1 Q2 Q3 Q4 CS Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 WR RD IBF OBF PSPIF PORTD<7:0> Q1 Q2 Q3 Q4 CS Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 WR IBF PSPIF RD OBF PORTD<7:0>PIC18F2420/2520/4420/4520 DS39631E-page 122 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 123 PIC18F2420/2520/4420/4520 11.0 TIMER0 MODULE The Timer0 module incorporates the following features: • Software selectable operation as a timer or counter in both 8-bit or 16-bit modes • Readable and writable registers • Dedicated 8-bit, software programmable prescaler • Selectable clock source (internal or external) • Edge select for external clock • Interrupt-on-overflow The T0CON register (Register 11-1) controls all aspects of the module’s operation, including the prescale selection. It is both readable and writable. A simplified block diagram of the Timer0 module in 8-bit mode is shown in Figure 11-1. Figure 11-2 shows a simplified block diagram of the Timer0 module in 16-bit mode. REGISTER 11-1: T0CON: TIMER0 CONTROL REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 TMR0ON: Timer0 On/Off Control bit 1 = Enables Timer0 0 = Stops Timer0 bit 6 T08BIT: Timer0 8-Bit/16-Bit Control bit 1 = Timer0 is configured as an 8-bit timer/counter 0 = Timer0 is configured as a 16-bit timer/counter bit 5 T0CS: Timer0 Clock Source Select bit 1 = Transition on T0CKI pin 0 = Internal instruction cycle clock (CLKO) bit 4 T0SE: Timer0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin bit 3 PSA: Timer0 Prescaler Assignment bit 1 = TImer0 prescaler is not assigned. Timer0 clock input bypasses prescaler. 0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output. bit 2-0 T0PS<2:0>: Timer0 Prescaler Select bits 111 = 1:256 Prescale value 110 = 1:128 Prescale value 101 = 1:64 Prescale value 100 = 1:32 Prescale value 011 = 1:16 Prescale value 010 = 1:8 Prescale value 001 = 1:4 Prescale value 000 = 1:2 Prescale valuePIC18F2420/2520/4420/4520 DS39631E-page 124 © 2008 Microchip Technology Inc. 11.1 Timer0 Operation Timer0 can operate as either a timer or a counter; the mode is selected with the T0CS bit (T0CON<5>). In Timer mode (T0CS = 0), the module increments on every clock by default unless a different prescaler value is selected (see Section 11.3 “Prescaler”). If the TMR0 register is written to, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0 register. The Counter mode is selected by setting the T0CS bit (= 1). In this mode, Timer0 increments either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit, T0SE (T0CON<4>); clearing this bit selects the rising edge. Restrictions on the external clock input are discussed below. An external clock source can be used to drive Timer0; however, it must meet certain requirements to ensure that the external clock can be synchronized with the internal phase clock (TOSC). There is a delay between synchronization and the onset of incrementing the timer/counter. 11.2 Timer0 Reads and Writes in 16-Bit Mode TMR0H is not the actual high byte of Timer0 in 16-bit mode; it is actually a buffered version of the real high byte of Timer0 which is not directly readable nor writable (refer to Figure 11-2). TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16 bits of Timer0 without having to verify that the read of the high and low byte were valid, due to a rollover between successive reads of the high and low byte. Similarly, a write to the high byte of Timer0 must also take place through the TMR0H Buffer register. The high byte is updated with the contents of TMR0H when a write occurs to TMR0L. This allows all 16 bits of Timer0 to be updated at once. FIGURE 11-1: TIMER0 BLOCK DIAGRAM (8-BIT MODE) FIGURE 11-2: TIMER0 BLOCK DIAGRAM (16-BIT MODE) Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. T0CKI pin T0SE 0 1 0 1 T0CS FOSC/4 Programmable Prescaler Sync with Internal Clocks TMR0L (2 TCY Delay) PSA Internal Data Bus T0PS<2:0> Set TMR0IF on Overflow 3 8 8 Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. T0CKI pin T0SE 0 1 0 1 T0CS FOSC/4 Programmable Prescaler Sync with Internal Clocks TMR0L (2 TCY Delay) Internal Data Bus 8 PSA T0PS<2:0> Set TMR0IF on Overflow 3 TMR0 TMR0H High Byte 8 8 8 Read TMR0L Write TMR0L 8© 2008 Microchip Technology Inc. DS39631E-page 125 PIC18F2420/2520/4420/4520 11.3 Prescaler An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not directly readable or writable; its value is set by the PSA and T0PS<2:0> bits (T0CON<3:0>) which determine the prescaler assignment and prescale ratio. Clearing the PSA bit assigns the prescaler to the Timer0 module. When it is assigned, prescale values from 1:2 through 1:256 in power-of-2 increments are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0 register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, etc.) clear the prescaler count. 11.3.1 SWITCHING PRESCALER ASSIGNMENT The prescaler assignment is fully under software control and can be changed “on-the-fly” during program execution. 11.4 Timer0 Interrupt The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or from FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF flag bit. The interrupt can be masked by clearing the TMR0IE bit (INTCON<5>). Before reenabling the interrupt, the TMR0IF bit must be cleared in software by the Interrupt Service Routine. Since Timer0 is shut down in Sleep mode, the TMR0 interrupt cannot awaken the processor from Sleep. TABLE 11-1: REGISTERS ASSOCIATED WITH TIMER0 Note: Writing to TMR0 when the prescaler is assigned to Timer0 will clear the prescaler count but will not change the prescaler assignment. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0L Timer0 Register Low Byte 50 TMR0H Timer0 Register High Byte 50 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 50 TRISA RA7(1) RA6(1) RA5 RA4 RA3 RA2 RA1 RA0 52 Legend: Shaded cells are not used by Timer0. Note 1: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’.PIC18F2420/2520/4420/4520 DS39631E-page 126 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 127 PIC18F2420/2520/4420/4520 12.0 TIMER1 MODULE The Timer1 timer/counter module incorporates these features: • Software selectable operation as a 16-bit timer or counter • Readable and writable 8-bit registers (TMR1H and TMR1L) • Selectable clock source (internal or external) with device clock or Timer1 oscillator internal options • Interrupt-on-overflow • Reset on CCP Special Event Trigger • Device clock status flag (T1RUN) A simplified block diagram of the Timer1 module is shown in Figure 12-1. A block diagram of the module’s operation in Read/Write mode is shown in Figure 12-2. The module incorporates its own low-power oscillator to provide an additional clocking option. The Timer1 oscillator can also be used as a low-power clock source for the microcontroller in power-managed operation. Timer1 can also be used to provide Real-Time Clock (RTC) functionality to applications with only a minimal addition of external components and code overhead. Timer1 is controlled through the T1CON Control register (Register 12-1). It also contains the Timer1 Oscillator Enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit, TMR1ON (T1CON<0>). REGISTER 12-1: T1CON: TIMER1 CONTROL REGISTER R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 RD16: 16-Bit Read/Write Mode Enable bit 1 = Enables register read/write of TImer1 in one 16-bit operation 0 = Enables register read/write of Timer1 in two 8-bit operations bit 6 T1RUN: Timer1 System Clock Status bit 1 = Device clock is derived from Timer1 oscillator 0 = Device clock is derived from another source bit 5-4 T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 3 T1OSCEN: Timer1 Oscillator Enable bit 1 = Timer1 oscillator is enabled 0 = Timer1 oscillator is shut off The oscillator inverter and feedback resistor are turned off to eliminate power drain. bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. bit 1 TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge) 0 = Internal clock (FOSC/4) bit 0 TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1PIC18F2420/2520/4420/4520 DS39631E-page 128 © 2008 Microchip Technology Inc. 12.1 Timer1 Operation Timer1 can operate in one of these modes: • Timer • Synchronous Counter • Asynchronous Counter The operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). When TMR1CS is cleared (= 0), Timer1 increments on every internal instruction cycle (FOSC/4). When the bit is set, Timer1 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. When Timer1 is enabled, the RC1/T1OSI and RC0/ T1OSO/T13CKI pins become inputs. This means the values of TRISC<1:0> are ignored and the pins are read as ‘0’. FIGURE 12-1: TIMER1 BLOCK DIAGRAM FIGURE 12-2: TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE) T1SYNC TMR1CS T1CKPS<1:0> Sleep Input T1OSCEN(1) FOSC/4 Internal Clock On/Off Prescaler 1, 2, 4, 8 Synchronize Detect 1 0 2 T1OSO/T13CKI T1OSI 1 0 TMR1ON TMR1L Set TMR1IF on Overflow TMR1 High Byte Clear TMR1 (CCP Special Event Trigger) Timer1 Oscillator Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. On/Off Timer1 Timer1 Clock Input T1SYNC TMR1CS T1CKPS<1:0> Sleep Input T1OSCEN(1) FOSC/4 Internal Clock Prescaler 1, 2, 4, 8 Synchronize Detect 1 0 2 T1OSO/T13CKI T1OSI Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. 1 0 TMR1L Internal Data Bus 8 Set TMR1IF on Overflow TMR1 TMR1H High Byte 8 8 8 Read TMR1L Write TMR1L 8 TMR1ON Clear TMR1 (CCP Special Event Trigger) Timer1 Oscillator On/Off Timer1 Timer1 Clock Input© 2008 Microchip Technology Inc. DS39631E-page 129 PIC18F2420/2520/4420/4520 12.2 Timer1 16-Bit Read/Write Mode Timer1 can be configured for 16-bit reads and writes (see Figure 12-2). When the RD16 control bit (T1CON<7>) is set, the address for TMR1H is mapped to a buffer register for the high byte of Timer1. A read from TMR1L will load the contents of the high byte of Timer1 into the Timer1 high byte buffer. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. A write to the high byte of Timer1 must also take place through the TMR1H Buffer register. The Timer1 high byte is updated with the contents of TMR1H when a write occurs to TMR1L. This allows a user to write all 16 bits to both the high and low bytes of Timer1 at once. The high byte of Timer1 is not directly readable or writable in this mode. All reads and writes must take place through the Timer1 High Byte Buffer register. Writes to TMR1H do not clear the Timer1 prescaler. The prescaler is only cleared on writes to TMR1L. 12.3 Timer1 Oscillator An on-chip crystal oscillator circuit is incorporated between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting the Timer1 Oscillator Enable bit, T1OSCEN (T1CON<3>). The oscillator is a lowpower circuit rated for 32 kHz crystals. It will continue to run during all power-managed modes. The circuit for a typical LP oscillator is shown in Figure 12-3. Table 12-1 shows the capacitor selection for the Timer1 oscillator. The user must provide a software time delay to ensure proper start-up of the Timer1 oscillator. FIGURE 12-3: EXTERNAL COMPONENTS FOR THE TIMER1 LP OSCILLATOR TABLE 12-1: CAPACITOR SELECTION FOR THE TIMER OSCILLATOR 12.3.1 USING TIMER1 AS A CLOCK SOURCE The Timer1 oscillator is also available as a clock source in power-managed modes. By setting the clock select bits, SCS<1:0> (OSCCON<1:0>), to ‘01’, the device switches to SEC_RUN mode; both the CPU and peripherals are clocked from the Timer1 oscillator. If the IDLEN bit (OSCCON<7>) is cleared and a SLEEP instruction is executed, the device enters SEC_IDLE mode. Additional details are available in Section 3.0 “Power-Managed Modes”. Whenever the Timer1 oscillator is providing the clock source, the Timer1 system clock status flag, T1RUN (T1CON<6>), is set. This can be used to determine the controller’s current clocking mode. It can also indicate the clock source being currently used by the Fail-Safe Clock Monitor. If the Clock Monitor is enabled and the Timer1 oscillator fails while providing the clock, polling the T1RUN bit will indicate whether the clock is being provided by the Timer1 oscillator or another source. 12.3.2 LOW-POWER TIMER1 OPTION The Timer1 oscillator can operate at two distinct levels of power consumption based on device configuration. When the LPT1OSC Configuration bit is set, the Timer1 oscillator operates in a low-power mode. When LPT1OSC is not set, Timer1 operates at a higher power level. Power consumption for a particular mode is relatively constant, regardless of the device’s operating mode. The default Timer1 configuration is the higher power mode. As the low-power Timer1 mode tends to be more sensitive to interference, high noise environments may cause some oscillator instability. The low-power option is, therefore, best suited for low noise applications where power conservation is an important design consideration. Note: See the Notes with Table 12-1 for additional information about capacitor selection. C1 C2 XTAL PIC18FXXXX T1OSI T1OSO 32.768 kHz 27 pF 27 pF Osc Type Freq C1 C2 LP 32 kHz 27 pF(1) 27 pF(1) Note 1: Microchip suggests these values as a starting point in validating the oscillator circuit. 2: Higher capacitance increases the stability of the oscillator but also increases the start-up time. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Capacitor values are for design guidance only.PIC18F2420/2520/4420/4520 DS39631E-page 130 © 2008 Microchip Technology Inc. 12.3.3 TIMER1 OSCILLATOR LAYOUT CONSIDERATIONS The Timer1 oscillator circuit draws very little power during operation. Due to the low-power nature of the oscillator, it may also be sensitive to rapidly changing signals in close proximity. The oscillator circuit, shown in Figure 12-3, should be located as close as possible to the microcontroller. There should be no circuits passing within the oscillator circuit boundaries other than VSS or VDD. If a high-speed circuit must be located near the oscillator (such as the CCP1 pin in Output Compare or PWM mode, or the primary oscillator using the OSC2 pin), a grounded guard ring around the oscillator circuit, as shown in Figure 12-4, may be helpful when used on a single-sided PCB or in addition to a ground plane. FIGURE 12-4: OSCILLATOR CIRCUIT WITH GROUNDED GUARD RING 12.4 Timer1 Interrupt The TMR1 register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The Timer1 interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR1IF (PIR1<0>). This interrupt can be enabled or disabled by setting or clearing the Timer1 Interrupt Enable bit, TMR1IE (PIE1<0>). 12.5 Resetting Timer1 Using the CCP Special Event Trigger If either of the CCP modules is configured to use Timer1 and generate a Special Event Trigger in Compare mode (CCP1M<3:0> or CCP2M<3:0> = 1011), this signal will reset Timer1. The trigger from CCP2 will also start an A/D conversion if the A/D module is enabled (see Section 15.3.4 “Special Event Trigger” for more information). The module must be configured as either a timer or a synchronous counter to take advantage of this feature. When used this way, the CCPRxH:CCPRxL register pair effectively becomes a Period register for Timer1. If Timer1 is running in Asynchronous Counter mode, this Reset operation may not work. In the event that a write to Timer1 coincides with a Special Event Trigger, the write operation will take precedence. 12.6 Using Timer1 as a Real-Time Clock Adding an external LP oscillator to Timer1 (such as the one described in Section 12.3 “Timer1 Oscillator”) gives users the option to include RTC functionality to their applications. This is accomplished with an inexpensive watch crystal to provide an accurate time base and several lines of application code to calculate the time. When operating in Sleep mode and using a battery or supercapacitor as a power source, it can completely eliminate the need for a separate RTC device and battery backup. The application code routine, RTCisr, shown in Example 12-1, demonstrates a simple method to increment a counter at one-second intervals using an Interrupt Service Routine. Incrementing the TMR1 register pair to overflow triggers the interrupt and calls the routine, which increments the seconds counter by one; additional counters for minutes and hours are incremented as the previous counter overflow. Since the register pair is 16 bits wide, counting up to overflow the register directly from a 32.768 kHz clock would take 2 seconds. To force the overflow at the required one-second intervals, it is necessary to preload it. The simplest method is to set the MSb of TMR1H with a BSF instruction. Note that the TMR1L register is never preloaded or altered; doing so may introduce cumulative error over many cycles. For this method to be accurate, Timer1 must operate in Asynchronous mode and the Timer1 overflow interrupt must be enabled (PIE1<0> = 1), as shown in the routine, RTCinit. The Timer1 oscillator must also be enabled and running at all times. VDD OSC1 VSS OSC2 RC0 RC1 RC2 Note: Not drawn to scale. Note: The Special Event Triggers from the CCP2 module will not set the TMR1IF interrupt flag bit (PIR1<0>). © 2008 Microchip Technology Inc. DS39631E-page 131 PIC18F2420/2520/4420/4520 12.7 Considerations in Asynchronous Counter Mode Following a Timer1 interrupt and an update to the TMR1 registers, the Timer1 module uses a falling edge on its clock source to trigger the next register update on the rising edge. If the update is completed after the clock input has fallen, the next rising edge will not be counted. If the application can reliably update TMR1 before the timer input goes low, no additional action is needed. Otherwise, an adjusted update can be performed following a later Timer1 increment. This can be done by monitoring TMR1L within the interrupt routine until it increments, and then updating the TMR1H:TMR1L register pair while the clock is low, or one-half of the period of the clock source. Assuming that Timer1 is being used as a Real-Time Clock, the clock source is a 32.768 kHz crystal oscillator; in this case, one half period of the clock is 15.25 μs. The Real-Time Clock application code in Example 12-1 shows a typical ISR for Timer1, as well as the optional code required if the update cannot be done reliably within the required interval. EXAMPLE 12-1: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE RTCinit MOVLW 80h ; Preload TMR1 register pair MOVWF TMR1H ; for 1 second overflow CLRF TMR1L MOVLW b’00001111’ ; Configure for external clock, MOVWF T1CON ; Asynchronous operation, external oscillator CLRF secs ; Initialize timekeeping registers CLRF mins ; MOVLW .12 MOVWF hours BSF PIE1, TMR1IE ; Enable Timer1 interrupt RETURN RTCisr ; Start ISR here ; Insert the next 4 lines of code when TMR1 ; can not be reliably updated before clock pulse goes low BTFSC TMR1L,0 ; wait for TMR1L<0> to become clear BRA $-2 ; (may already be clear) BTFSS TMR1L,0 ; wait for TMR1L<0> to become set BRA $-2 ; TMR1 has just incremented ; If TMR1 update can be completed before clock pulse goes low BSF TMR1H, 7 ; Preload for 1 sec overflow BCF PIR1, TMR1IF ; Clear interrupt flag INCF secs, F ; Increment seconds MOVLW .59 ; 60 seconds elapsed? CPFSGT secs RETURN ; No, done CLRF secs ; Clear seconds INCF mins, F ; Increment minutes MOVLW .59 ; 60 minutes elapsed? CPFSGT mins RETURN ; No, done CLRF mins ; clear minutes INCF hours, F ; Increment hours MOVLW .23 ; 24 hours elapsed? CPFSGT hours RETURN ; No, done CLRF hours ; Reset hours RETURN ; DonePIC18F2420/2520/4420/4520 DS39631E-page 132 © 2008 Microchip Technology Inc. TABLE 12-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 TMR1L Timer1 Register Low Byte 50 TMR1H Timer1 Register High Byte 50 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 50 Legend: Shaded cells are not used by the Timer1 module. Note 1: These bits are unimplemented on 28-pin devices; always maintain these bits clear.© 2008 Microchip Technology Inc. DS39631E-page 133 PIC18F2420/2520/4420/4520 13.0 TIMER2 MODULE The Timer2 module timer incorporates the following features: • 8-Bit Timer and Period registers (TMR2 and PR2, respectively) • Readable and writable (both registers) • Software programmable prescaler (1:1, 1:4 and 1:16) • Software programmable postscaler (1:1 through 1:16) • Interrupt on TMR2 to PR2 match • Optional use as the shift clock for the MSSP module The module is controlled through the T2CON register (Register 13-1), which enables or disables the timer and configures the prescaler and postscaler. Timer2 can be shut off by clearing control bit, TMR2ON (T2CON<2>), to minimize power consumption. A simplified block diagram of the module is shown in Figure 13-1. 13.1 Timer2 Operation In normal operation, TMR2 is incremented from 00h on each clock (FOSC/4). A 4-bit counter/prescaler on the clock input gives direct input, divide-by-4 and divide-by- 16 prescale options; these are selected by the prescaler control bits, T2CKPS<1:0> (T2CON<1:0>). The value of TMR2 is compared to that of the Period register, PR2, on each clock cycle. When the two values match, the comparator generates a match signal as the timer output. This signal also resets the value of TMR2 to 00h on the next cycle and drives the output counter/postscaler (see Section 13.2 “Timer2 Interrupt”). The TMR2 and PR2 registers are both directly readable and writable. The TMR2 register is cleared on any device Reset, while the PR2 register initializes at FFh. Both the prescaler and postscaler counters are cleared on the following events: • a write to the TMR2 register • a write to the T2CON register • any device Reset (Power-on Reset, MCLR Reset, Watchdog Timer Reset or Brown-out Reset) TMR2 is not cleared when T2CON is written. REGISTER 13-1: T2CON: TIMER2 CONTROL REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 Unimplemented: Read as ‘0’ bit 6-3 T2OUTPS<3:0>: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale • • • 1111 = 1:16 Postscale bit 2 TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off bit 1-0 T2CKPS<1:0>: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16PIC18F2420/2520/4420/4520 DS39631E-page 134 © 2008 Microchip Technology Inc. 13.2 Timer2 Interrupt Timer2 also can generate an optional device interrupt. The Timer2 output signal (TMR2 to PR2 match) provides the input for the 4-bit output counter/postscaler. This counter generates the TMR2 match interrupt flag which is latched in TMR2IF (PIR1<1>). The interrupt is enabled by setting the TMR2 Match Interrupt Enable bit, TMR2IE (PIE1<1>). A range of 16 postscale options (from 1:1 through 1:16 inclusive) can be selected with the postscaler control bits, T2OUTPS<3:0> (T2CON<6:3>). 13.3 Timer2 Output The unscaled output of TMR2 is available primarily to the CCP modules, where it is used as a time base for operations in PWM mode. Timer2 can optionally be used as the shift clock source for the MSSP module operating in SPI mode. Additional information is provided in Section 17.0 “Master Synchronous Serial Port (MSSP) Module”. FIGURE 13-1: TIMER2 BLOCK DIAGRAM TABLE 13-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 TMR2 Timer2 Register 50 T2CON — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 50 PR2 Timer2 Period Register 50 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module. Note 1: These bits are unimplemented on 28-pin devices; always maintain these bits clear. Comparator TMR2 Output TMR2 Postscaler Prescaler PR2 2 FOSC/4 1:1 to 1:16 1:1, 1:4, 1:16 4 T2OUTPS<3:0> T2CKPS<1:0> Set TMR2IF Internal Data Bus 8 Reset TMR2/PR2 8 8 (to PWM or MSSP) Match© 2008 Microchip Technology Inc. DS39631E-page 135 PIC18F2420/2520/4420/4520 14.0 TIMER3 MODULE The Timer3 module timer/counter incorporates these features: • Software selectable operation as a 16-bit timer or counter • Readable and writable 8-bit registers (TMR3H and TMR3L) • Selectable clock source (internal or external) with device clock or Timer1 oscillator internal options • Interrupt-on-overflow • Module Reset on CCP Special Event Trigger A simplified block diagram of the Timer3 module is shown in Figure 14-1. A block diagram of the module’s operation in Read/Write mode is shown in Figure 14-2. The Timer3 module is controlled through the T3CON register (Register 14-1). It also selects the clock source options for the CCP modules (see Section 15.1.1 “CCP Modules and Timer Resources” for more information). REGISTER 14-1: T3CON: TIMER3 CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 RD16: 16-Bit Read/Write Mode Enable bit 1 = Enables register read/write of Timer3 in one 16-bit operation 0 = Enables register read/write of Timer3 in two 8-bit operations bit 6,3 T3CCP<2:1>: Timer3 and Timer1 to CCPx Enable bits 1x = Timer3 is the capture/compare clock source for the CCP modules 01 = Timer3 is the capture/compare clock source for CCP2; Timer1 is the capture/compare clock source for CCP1 00 = Timer1 is the capture/compare clock source for the CCP modules bit 5-4 T3CKPS<1:0>: Timer3 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the device clock comes from Timer1/Timer3.) When TMR3CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR3CS = 0: This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0. bit 1 TMR3CS: Timer3 Clock Source Select bit 1 = External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first falling edge) 0 = Internal clock (FOSC/4) bit 0 TMR3ON: Timer3 On bit 1 = Enables Timer3 0 = Stops Timer3PIC18F2420/2520/4420/4520 DS39631E-page 136 © 2008 Microchip Technology Inc. 14.1 Timer3 Operation Timer3 can operate in one of three modes: • Timer • Synchronous Counter • Asynchronous Counter The operating mode is determined by the clock select bit, TMR3CS (T3CON<1>). When TMR3CS is cleared (= 0), Timer3 increments on every internal instruction cycle (FOSC/4). When the bit is set, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. As with Timer1, the RC1/T1OSI and RC0/T1OSO/ T13CKI pins become inputs when the Timer1 oscillator is enabled. This means the values of TRISC<1:0> are ignored and the pins are read as ‘0’. FIGURE 14-1: TIMER3 BLOCK DIAGRAM FIGURE 14-2: TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE) T3SYNC TMR3CS T3CKPS<1:0> Sleep Input T1OSCEN(1) FOSC/4 Internal Clock Prescaler 1, 2, 4, 8 Synchronize Detect 1 0 2 T1OSO/T13CKI T1OSI 1 0 TMR3ON TMR3L Set TMR3IF on Overflow TMR3 High Byte Timer1 Oscillator Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. On/Off Timer3 CCP1/CCP2 Special Event Trigger CCP1/CCP2 Select from T3CON<6,3> Clear TMR3 Timer1 Clock Input T3SYNC TMR3CS T3CKPS<1:0> Sleep Input T1OSCEN(1) FOSC/4 Internal Clock Prescaler 1, 2, 4, 8 Synchronize Detect 1 0 2 T13CKI/T1OSO T1OSI Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. 1 0 TMR3L Internal Data Bus 8 Set TMR3IF on Overflow TMR3 TMR3H High Byte 8 8 8 Read TMR1L Write TMR1L 8 TMR3ON CCP1/CCP2 Special Event Trigger Timer1 Oscillator On/Off Timer3 Timer1 Clock Input CCP1/CCP2 Select from T3CON<6,3> Clear TMR3© 2008 Microchip Technology Inc. DS39631E-page 137 PIC18F2420/2520/4420/4520 14.2 Timer3 16-Bit Read/Write Mode Timer3 can be configured for 16-bit reads and writes (see Figure 14-2). When the RD16 control bit (T3CON<7>) is set, the address for TMR3H is mapped to a buffer register for the high byte of Timer3. A read from TMR3L will load the contents of the high byte of Timer3 into the Timer3 High Byte Buffer register. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. A write to the high byte of Timer3 must also take place through the TMR3H Buffer register. The Timer3 high byte is updated with the contents of TMR3H when a write occurs to TMR3L. This allows a user to write all 16 bits to both the high and low bytes of Timer3 at once. The high byte of Timer3 is not directly readable or writable in this mode. All reads and writes must take place through the Timer3 High Byte Buffer register. Writes to TMR3H do not clear the Timer3 prescaler. The prescaler is only cleared on writes to TMR3L. 14.3 Using the Timer1 Oscillator as the Timer3 Clock Source The Timer1 internal oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN (T1CON<3>) bit. To use it as the Timer3 clock source, the TMR3CS bit must also be set. As previously noted, this also configures Timer3 to increment on every rising edge of the oscillator source. The Timer1 oscillator is described in Section 12.0 “Timer1 Module”. 14.4 Timer3 Interrupt The TMR3 register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and overflows to 0000h. The Timer3 interrupt, if enabled, is generated on overflow and is latched in interrupt flag bit, TMR3IF (PIR2<1>). This interrupt can be enabled or disabled by setting or clearing the Timer3 Interrupt Enable bit, TMR3IE (PIE2<1>). 14.5 Resetting Timer3 Using the CCP Special Event Trigger If either of the CCP modules is configured to use Timer3 and to generate a Special Event Trigger in Compare mode (CCP1M<3:0> or CCP2M<3:0> = 1011), this signal will reset Timer3. It will also start an A/D conversion if the A/D module is enabled (see Section 15.3.4 “Special Event Trigger” for more information). The module must be configured as either a timer or synchronous counter to take advantage of this feature. When used this way, the CCPRxH:CCPRxL register pair effectively becomes a Period register for Timer3. If Timer3 is running in Asynchronous Counter mode, the Reset operation may not work. In the event that a write to Timer3 coincides with a Special Event Trigger from a CCP module, the write will take precedence. TABLE 14-1: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER Note: The Special Event Triggers from the CCP2 module will not set the TMR3IF interrupt flag bit (PIR1<0>). Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 TMR3L Timer3 Register Low Byte 51 TMR3H Timer3 Register High Byte 51 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 50 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.PIC18F2420/2520/4420/4520 DS39631E-page 138 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 139 PIC18F2420/2520/4420/4520 15.0 CAPTURE/COMPARE/PWM (CCP) MODULES PIC18F2420/2520/4420/4520 devices all have two CCP (Capture/Compare/PWM) modules. Each module contains a 16-bit register which can operate as a 16-bit Capture register, a 16-bit Compare register or a PWM Master/Slave Duty Cycle register. In 28-pin devices, the two standard CCP modules (CCP1 and CCP2) operate as described in this chapter. In 40/ 44-pin devices, CCP1 is implemented as an Enhanced CCP module with standard Capture and Compare modes and Enhanced PWM modes. The ECCP implementation is discussed in Section 16.0 “Enhanced Capture/Compare/PWM (ECCP) Module”. The capture and compare operations described in this chapter apply to all standard and Enhanced CCP modules. Note: Throughout this section and Section 16.0 “Enhanced Capture/Compare/PWM (ECCP) Module”, references to the register and bit names for CCP modules are referred to generically by the use of ‘x’ or ‘y’ in place of the specific module number. Thus, “CCPxCON” might refer to the control register for CCP1, CCP2 or ECCP1. “CCPxCON” is used throughout these sections to refer to the module control register, regardless of whether the CCP module is a standard or enhanced implementation. REGISTER 15-1: CCPxCON: CCPx CONTROL REGISTER (28-PIN DEVICES) U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-6 Unimplemented: Read as ‘0’ bit 5-4 DCxB<1:0>: PWM Duty Cycle bit 1 and bit 0 for CCPx Module Capture mode: Unused. Compare mode: Unused. PWM mode: These bits are the two LSbs (bit 1 and bit 0) of the 10-bit PWM duty cycle. The eight MSbs (DCxB<9:2>) of the duty cycle are found in CCPRxL. bit 3-0 CCPxM<3:0>: CCPx Module Mode Select bits 0000 = Capture/Compare/PWM disabled (resets CCPx module) 0001 = Reserved 0010 = Compare mode, toggle output on match (CCPxIF bit is set) 0011 = Reserved 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode, initialize CCPx pin low; on compare match, force CCPx pin high (CCPxIF bit is set) 1001 = Compare mode, initialize CCPx pin high; on compare match, force CCPx pin low (CCPxIF bit is set) 1010 = Compare mode, generate software interrupt on compare match (CCPxIF bit is set, CCPx pin reflects I/O state) 1011 = Compare mode, trigger special event; reset timer; CCP2 match starts A/D conversion (CCPxIF bit is set) 11xx = PWM modePIC18F2420/2520/4420/4520 DS39631E-page 140 © 2008 Microchip Technology Inc. 15.1 CCP Module Configuration Each Capture/Compare/PWM module is associated with a control register (generically, CCPxCON) and a data register (CCPRx). The data register, in turn, is comprised of two 8-bit registers: CCPRxL (low byte) and CCPRxH (high byte). All registers are both readable and writable. 15.1.1 CCP MODULES AND TIMER RESOURCES The CCP modules utilize Timers 1, 2 or 3, depending on the mode selected. Timer1 and Timer3 are available to modules in Capture or Compare modes, while Timer2 is available for modules in PWM mode. TABLE 15-1: CCP MODE – TIMER RESOURCE The assignment of a particular timer to a module is determined by the Timer to CCP enable bits in the T3CON register (Register 14-1). Both modules may be active at any given time and may share the same timer resource if they are configured to operate in the same mode (Capture/Compare or PWM) at the same time. The interactions between the two modules are summarized in Figure 15-1 and Figure 15-2. In Timer1 in Asynchronous Counter mode, the capture operation will not work. 15.1.2 CCP2 PIN ASSIGNMENT The pin assignment for CCP2 (Capture input, Compare and PWM output) can change, based on device configuration. The CCP2MX Configuration bit determines which pin CCP2 is multiplexed to. By default, it is assigned to RC1 (CCP2MX = 1). If the Configuration bit is cleared, CCP2 is multiplexed with RB3. Changing the pin assignment of CCP2 does not automatically change any requirements for configuring the port pin. Users must always verify that the appropriate TRIS register is configured correctly for CCP2 operation, regardless of where it is located. TABLE 15-2: INTERACTIONS BETWEEN CCP1 AND CCP2 FOR TIMER RESOURCES CCP/ECCP Mode Timer Resource Capture Compare PWM Timer1 or Timer3 Timer1 or Timer3 Timer2 CCP1 Mode CCP2 Mode Interaction Capture Capture Each module can use TMR1 or TMR3 as the time base. The time base can be different for each CCP. Capture Compare CCP2 can be configured for the Special Event Trigger to reset TMR1 or TMR3 (depending upon which time base is used). Automatic A/D conversions on trigger event can also be done. Operation of CCP1 could be affected if it is using the same timer as a time base. Compare Capture CCP1 can be configured for the Special Event Trigger to reset TMR1 or TMR3 (depending upon which time base is used). Operation of CCP2 could be affected if it is using the same timer as a time base. Compare Compare Either module can be configured for the Special Event Trigger to reset the time base. Automatic A/D conversions on CCP2 trigger event can be done. Conflicts may occur if both modules are using the same time base. Capture PWM(1) None Compare PWM(1) None PWM(1) Capture None PWM(1) Compare None PWM(1) PWM(1) Both PWMs will have the same frequency and update rate (TMR2 interrupt). Note 1: Includes standard and Enhanced PWM operation.© 2008 Microchip Technology Inc. DS39631E-page 141 PIC18F2420/2520/4420/4520 15.2 Capture Mode In Capture mode, the CCPRxH:CCPRxL register pair captures the 16-bit value of the TMR1 or TMR3 register when an event occurs on the corresponding CCPx pin. An event is defined as one of the following: • every falling edge • every rising edge • every 4th rising edge • every 16th rising edge The event is selected by the mode select bits, CCPxM<3:0> (CCPxCON<3:0>). When a capture is made, the interrupt request flag bit, CCPxIF, is set; it must be cleared in software. If another capture occurs before the value in register CCPRx is read, the old captured value is overwritten by the new captured value. 15.2.1 CCP PIN CONFIGURATION In Capture mode, the appropriate CCPx pin should be configured as an input by setting the corresponding TRIS direction bit. 15.2.2 TIMER1/TIMER3 MODE SELECTION The timers that are to be used with the capture feature (Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation will not work. The timer to be used with each CCP module is selected in the T3CON register (see Section 15.1.1 “CCP Modules and Timer Resources”). 15.2.3 SOFTWARE INTERRUPT When the Capture mode is changed, a false capture interrupt may be generated. The user should keep the CCPxIE interrupt enable bit clear to avoid false interrupts. The interrupt flag bit, CCPxIF, should also be cleared following any such change in operating mode. 15.2.4 CCP PRESCALER There are four prescaler settings in Capture mode; they are specified as part of the operating mode selected by the mode select bits (CCPxM<3:0>). Whenever the CCP module is turned off, or Capture mode is disabled, the prescaler counter is cleared. This means that any Reset will clear the prescaler counter. Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared; therefore, the first capture may be from a non-zero prescaler. Example 15-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the “false” interrupt. EXAMPLE 15-1: CHANGING BETWEEN CAPTURE PRESCALERS (CCP2 SHOWN) FIGURE 15-1: CAPTURE MODE OPERATION BLOCK DIAGRAM Note: If RB3/CCP2 or RC1/CCP2 is configured as an output, a write to the port can cause a capture condition. CLRF CCP2CON ; Turn CCP module off MOVLW NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON MOVWF CCP2CON ; Load CCP2CON with ; this value CCPR1H CCPR1L TMR1H TMR1L Set CCP1IF TMR3 Enable Q1:Q4 CCP1CON<3:0> CCP1 pin Prescaler ÷ 1, 4, 16 and Edge Detect TMR1 Enable T3CCP2 T3CCP2 CCPR2H CCPR2L TMR1H TMR1L Set CCP2IF TMR3 Enable CCP2CON<3:0> CCP2 pin Prescaler ÷ 1, 4, 16 TMR3H TMR3L TMR1 Enable T3CCP2 T3CCP1 T3CCP2 T3CCP1 TMR3H TMR3L and Edge Detect 4 4 4PIC18F2420/2520/4420/4520 DS39631E-page 142 © 2008 Microchip Technology Inc. 15.3 Compare Mode In Compare mode, the 16-bit CCPRx register value is constantly compared against either the TMR1 or TMR3 register pair value. When a match occurs, the CCPx pin can be: • driven high • driven low • toggled (high-to-low or low-to-high) • remain unchanged (that is, reflects the state of the I/O latch) The action on the pin is based on the value of the mode select bits (CCPxM<3:0>). At the same time, the interrupt flag bit, CCPxIF, is set. 15.3.1 CCP PIN CONFIGURATION The user must configure the CCPx pin as an output by clearing the appropriate TRIS bit. 15.3.2 TIMER1/TIMER3 MODE SELECTION Timer1 and/or Timer3 must be running in Timer mode or Synchronized Counter mode if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work. 15.3.3 SOFTWARE INTERRUPT MODE When the Generate Software Interrupt mode is chosen (CCPxM<3:0> = 1010), the corresponding CCPx pin is not affected. A CCP interrupt is generated when the CCPxIF interrupt flag is set while the CCPxIE bit is set. 15.3.4 SPECIAL EVENT TRIGGER Both CCP modules are equipped with a Special Event Trigger. This is an internal hardware signal generated in Compare mode to trigger actions by other modules. The Special Event Trigger is enabled by selecting the Compare Special Event Trigger mode (CCPxM<3:0> = 1011). For either CCP module, the Special Event Trigger resets the Timer register pair for whichever timer resource is currently assigned as the module’s time base. This allows the CCPRx registers to serve as a programmable Period register for either timer. The Special Event Trigger for CCP2 can also start an A/D conversion. In order to do this, the A/D Converter must already be enabled. FIGURE 15-2: COMPARE MODE OPERATION BLOCK DIAGRAM Note: Clearing the CCP2CON register will force the RB3 or RC1 compare output latch (depending on device configuration) to the default low level. This is not the PORTB or PORTC I/O data latch. CCPR1H CCPR1L TMR1H TMR1L Comparator S Q R Output Logic Special Event Trigger Set CCP1IF CCP1 pin TRIS CCP1CON<3:0> Output Enable TMR3H TMR3L CCPR2H CCPR2L Comparator 1 0 T3CCP2 T3CCP1 Set CCP2IF 1 0 Compare 4 (Timer1/Timer3 Reset) S Q R Output Logic Special Event Trigger CCP2 pin TRIS CCP2CON<3:0> 4 Output Enable (Timer1/Timer3 Reset, A/D Trigger) Match Compare Match© 2008 Microchip Technology Inc. DS39631E-page 143 PIC18F2420/2520/4420/4520 TABLE 15-3: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 RCON IPEN SBOREN — RI TO PD POR BOR 48 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 TRISB PORTB Data Direction Register 52 TRISC PORTC Data Direction Register 52 TMR1L Timer1 Register Low Byte 50 TMR1H Timer1 Register High Byte 50 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 50 TMR3H Timer3 Register High Byte 51 TMR3L Timer3 Register Low Byte 51 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 51 CCPR1L Capture/Compare/PWM Register 1 Low Byte 51 CCPR1H Capture/Compare/PWM Register 1 High Byte 51 CCP1CON P1M1(1) P1M0(1) DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 51 CCPR2L Capture/Compare/PWM Register 2 Low Byte 51 CCPR2H Capture/Compare/PWM Register 2 High Byte 51 CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by Capture/Compare, Timer1 or Timer3. Note 1: These bits are unimplemented on 28-pin devices; always maintain these bits clear.PIC18F2420/2520/4420/4520 DS39631E-page 144 © 2008 Microchip Technology Inc. 15.4 PWM Mode In Pulse-Width Modulation (PWM) mode, the CCPx pin produces up to a 10-bit resolution PWM output. Since the CCP2 pin is multiplexed with a PORTB or PORTC data latch, the appropriate TRIS bit must be cleared to make the CCP2 pin an output. Figure 15-3 shows a simplified block diagram of the CCP module in PWM mode. For a step-by-step procedure on how to set up the CCP module for PWM operation, see Section 15.4.4 “Setup for PWM Operation”. FIGURE 15-3: SIMPLIFIED PWM BLOCK DIAGRAM A PWM output (Figure 15-4) has a time base (period) and a time that the output stays high (duty cycle). The frequency of the PWM is the inverse of the period (1/period). FIGURE 15-4: PWM OUTPUT 15.4.1 PWM PERIOD The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula: EQUATION 15-1: PWM frequency is defined as 1/[PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: • TMR2 is cleared • The CCPx pin is set (exception: if PWM duty cycle = 0%, the CCPx pin will not be set) • The PWM duty cycle is latched from CCPRxL into CCPRxH 15.4.2 PWM DUTY CYCLE The PWM duty cycle is specified by writing to the CCPRxL register and to the CCPxCON<5:4> bits. Up to 10-bit resolution is available. The CCPRxL contains the eight MSbs and the CCPxCON<5:4> bits contain the two LSbs. This 10-bit value is represented by CCPRxL:CCPxCON<5:4>. The following equation is used to calculate the PWM duty cycle in time: EQUATION 15-2: CCPRxL and CCPxCON<5:4> can be written to at any time, but the duty cycle value is not latched into CCPRxH until after a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPRxH is a read-only register. Note: Clearing the CCP2CON register will force the RB3 or RC1 output latch (depending on device configuration) to the default low level. This is not the PORTB or PORTC I/O data latch. CCPRxL CCPRxH (Slave) Comparator TMR2 Comparator PR2 (Note 1) R Q S Duty Cycle Registers CCPxCON<5:4> Clear Timer, CCPx pin and latch D.C. Note 1: The 8-bit TMR2 value is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create the 10-bit time base. CCPx Output Corresponding TRIS bit Period Duty Cycle TMR2 = PR2 TMR2 = Duty Cycle TMR2 = PR2 Note: The Timer2 postscalers (see Section 13.0 “Timer2 Module”) are not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output. PWM Period = [(PR2) + 1] • 4 • TOSC • (TMR2 Prescale Value) PWM Duty Cycle = (CCPRXL:CCPXCON<5:4>) • TOSC • (TMR2 Prescale Value)© 2008 Microchip Technology Inc. DS39631E-page 145 PIC18F2420/2520/4420/4520 The CCPRxH register and a 2-bit internal latch are used to double-buffer the PWM duty cycle. This double-buffering is essential for glitchless PWM operation. When the CCPRxH and 2-bit latch match TMR2, concatenated with an internal 2-bit Q clock or 2 bits of the TMR2 prescaler, the CCPx pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the equation: EQUATION 15-3: TABLE 15-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz 15.4.3 PWM AUTO-SHUTDOWN (CCP1 ONLY) The PWM auto-shutdown features of the Enhanced CCP module are also available to CCP1 in 28-pin devices. The operation of this feature is discussed in detail in Section 16.4.7 “Enhanced PWM Auto-Shutdown”. Auto-shutdown features are not available for CCP2. 15.4.4 SETUP FOR PWM OPERATION The following steps should be taken when configuring the CCP module for PWM operation: 1. Set the PWM period by writing to the PR2 register. 2. Set the PWM duty cycle by writing to the CCPRxL register and CCPxCON<5:4> bits. 3. Make the CCPx pin an output by clearing the appropriate TRIS bit. 4. Set the TMR2 prescale value, then enable Timer2 by writing to T2CON. 5. Configure the CCPx module for PWM operation. Note: If the PWM duty cycle value is longer than the PWM period, the CCPx pin will not be cleared. FOSC FPWM --------------- ⎝ ⎠ ⎛ ⎞ log log( ) 2 PWM Resolution (max) = -----------------------------bits PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz Timer Prescaler (1, 4, 16) 16 4 1 1 1 1 PR2 Value FFh FFh FFh 3Fh 1Fh 17h Maximum Resolution (bits) 10 10 10 8 7 6.58PIC18F2420/2520/4420/4520 DS39631E-page 146 © 2008 Microchip Technology Inc. TABLE 15-5: REGISTERS ASSOCIATED WITH PWM AND TIMER2 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 RCON IPEN SBOREN — RI TO PD POR BOR 48 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 TRISB PORTB Data Direction Register 52 TRISC PORTC Data Direction Register 52 TMR2 Timer2 Register 50 PR2 Timer2 Period Register 50 T2CON — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 50 CCPR1L Capture/Compare/PWM Register 1 Low Byte 51 CCPR1H Capture/Compare/PWM Register 1 High Byte 51 CCP1CON P1M1(1) P1M0(1) DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 51 CCPR2L Capture/Compare/PWM Register 2 Low Byte 51 CCPR2H Capture/Compare/PWM Register 2 High Byte 51 CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 51 ECCP1AS ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1(1) PSSBD0(1) 51 PWM1CON PRSEN PDC6(1) PDC5(1) PDC4(1) PDC3(1) PDC2(1) PDC1(1) PDC0(1) 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PWM or Timer2. Note 1: These bits are unimplemented on 28-pin devices; always maintain these bits clear.© 2008 Microchip Technology Inc. DS39631E-page 147 PIC18F2420/2520/4420/4520 16.0 ENHANCED CAPTURE/ COMPARE/PWM (ECCP) MODULE In PIC18F4420/4520 devices, CCP1 is implemented as a standard CCP module with Enhanced PWM capabilities. These include the provision for 2 or 4 output channels, user-selectable polarity, dead-band control and automatic shutdown and restart. The enhanced features are discussed in detail in Section 16.4 “Enhanced PWM Mode”. Capture, Compare and single output PWM functions of the ECCP module are the same as described for the standard CCP module. The control register for the Enhanced CCP module is shown in Register 16-2. It differs from the CCPxCON registers in PIC18F2420/2520 devices in that the two Most Significant bits are implemented to control PWM functionality. Note: The ECCP module is implemented only in 40/44-pin devices. REGISTER 16-1: CCP1CON: ECCP CONTROL REGISTER (40/44-PIN DEVICES) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-6 P1M<1:0>: Enhanced PWM Output Configuration bits If CCP1M3:CCP1M2 = 00, 01, 10: xx = P1A assigned as capture/compare input/output; P1B, P1C, P1D assigned as port pins If CCP1M3:CCP1M2 = 11: 00 = Single output, P1A modulated; P1B, P1C, P1D assigned as port pins 01 = Full-bridge output forward, P1D modulated; P1A active; P1B, P1C inactive 10 = Half-bridge output, P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins 11 = Full-bridge output reverse, P1B modulated; P1C active; P1A, P1D inactive bit 5-4 DC1B<1:0>: PWM Duty Cycle bit 1 and bit 0 Capture mode: Unused. Compare mode: Unused. PWM mode: These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found in CCPR1L. bit 3-0 CCP1M<3:0>: Enhanced CCP Mode Select bits 0000 = Capture/Compare/PWM off (resets ECCP module) 0001 = Reserved 0010 = Compare mode, toggle output on match 0011 = Capture mode 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode, initialize CCP1 pin low; set output on compare match (set CCP1IF) 1001 = Compare mode, initialize CCP1 pin high; clear output on compare match (set CCP1IF) 1010 = Compare mode, generate software interrupt only; CCP1 pin reverts to I/O state 1011 = Compare mode, trigger special event (ECCP resets TMR1 or TMR3, sets CCP1IF bit) 1100 = PWM mode, P1A, P1C active-high; P1B, P1D active-high 1101 = PWM mode, P1A, P1C active-high; P1B, P1D active-low 1110 = PWM mode, P1A, P1C active-low; P1B, P1D active-high 1111 = PWM mode, P1A, P1C active-low; P1B, P1D active-lowPIC18F2420/2520/4420/4520 DS39631E-page 148 © 2008 Microchip Technology Inc. In addition to the expanded range of modes available through the CCP1CON register and ECCP1AS register, the ECCP module has an additional register associated with Enhanced PWM operation and auto-shutdown features. It is: • PWM1CON (PWM Dead-Band Delay) 16.1 ECCP Outputs and Configuration The Enhanced CCP module may have up to four PWM outputs, depending on the selected operating mode. These outputs, designated P1A through P1D, are multiplexed with I/O pins on PORTC and PORTD. The outputs that are active depend on the CCP operating mode selected. The pin assignments are summarized in Table 16-1. To configure the I/O pins as PWM outputs, the proper PWM mode must be selected by setting the P1M<1:0> and CCP1M<3:0> bits. The appropriate TRISC and TRISD direction bits for the port pins must also be set as outputs. 16.1.1 ECCP MODULES AND TIMER RESOURCES Like the standard CCP modules, the ECCP module can utilize Timers 1, 2 or 3, depending on the mode selected. Timer1 and Timer3 are available for modules in Capture or Compare modes, while Timer2 is available for modules in PWM mode. Interactions between the standard and Enhanced CCP modules are identical to those described for standard CCP modules. Additional details on timer resources are provided in Section 15.1.1 “CCP Modules and Timer Resources”. 16.2 Capture and Compare Modes Except for the operation of the Special Event Trigger discussed below, the Capture and Compare modes of the ECCP module are identical in operation to that of CCP2. These are discussed in detail in Section 15.2 “Capture Mode” and Section 15.3 “Compare Mode”. No changes are required when moving between 28-pin and 40/44-pin devices. 16.2.1 SPECIAL EVENT TRIGGER The Special Event Trigger output of ECCP resets the TMR1 or TMR3 register pair, depending on which timer resource is currently selected. This allows the CCPR1 register to effectively be a 16-Bit Programmable Period register for Timer1 or Timer3. 16.3 Standard PWM Mode When configured in Single Output mode, the ECCP module functions identically to the standard CCP module in PWM mode, as described in Section 15.4 “PWM Mode”. This is also sometimes referred to as “Compatible CCP” mode, as in Table 16-1. TABLE 16-1: PIN ASSIGNMENTS FOR VARIOUS ECCP MODES Note: When setting up single output PWM operations, users are free to use either of the processes described in Section 15.4.4 “Setup for PWM Operation” or Section 16.4.9 “Setup for PWM Operation”. The latter is more generic and will work for either single or multi-output PWM. ECCP Mode CCP1CON Configuration RC2 RD5 RD6 RD7 All 40/44-Pin Devices: Compatible CCP 00xx 11xx CCP1 RD5/PSP5 RD6/PSP6 RD7/PSP7 Dual PWM 10xx 11xx P1A P1B RD6/PSP6 RD7/PSP7 Quad PWM x1xx 11xx P1A P1B P1C P1D Legend: x = Don’t care. Shaded cells indicate pin assignments not used by ECCP in a given mode.© 2008 Microchip Technology Inc. DS39631E-page 149 PIC18F2420/2520/4420/4520 16.4 Enhanced PWM Mode The Enhanced PWM mode provides additional PWM output options for a broader range of control applications. The module is a backward compatible version of the standard CCP module and offers up to four outputs, designated P1A through P1D. Users are also able to select the polarity of the signal (either active-high or active-low). The module’s output mode and polarity are configured by setting the P1M<1:0> and CCP1M<3:0> bits of the CCP1CON register. Figure 16-1 shows a simplified block diagram of PWM operation. All control registers are double-buffered and are loaded at the beginning of a new PWM cycle (the period boundary when Timer2 resets) in order to prevent glitches on any of the outputs. The exception is the PWM Dead-Band Delay register, PWM1CON, which is loaded at either the duty cycle boundary or the period boundary (whichever comes first). Because of the buffering, the module waits until the assigned timer resets instead of starting immediately. This means that Enhanced PWM waveforms do not exactly match the standard PWM waveforms, but are instead offset by one full instruction cycle (4 TOSC). As before, the user must manually configure the appropriate TRIS bits for output. 16.4.1 PWM PERIOD The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following equation. EQUATION 16-1: PWM frequency is defined as 1/[PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: • TMR2 is cleared • The CCP1 pin is set (if PWM duty cycle = 0%, the CCP1 pin will not be set) • The PWM duty cycle is copied from CCPR1L into CCPR1H FIGURE 16-1: SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODULE Note: The Timer2 postscaler (see Section 13.0 “Timer2 Module”) is not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output. PWM Period = [(PR2) + 1] • 4 • TOSC • (TMR2 Prescale Value) CCPR1L CCPR1H (Slave) Comparator TMR2 Comparator PR2 (Note 1) R Q S Duty Cycle Registers CCP1CON<5:4> Clear Timer, set CCP1 pin and latch D.C. Note: The 8-bit TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create the 10-bit time base. TRISx CCP1/P1A TRISx P1B TRISx TRISx P1D Output Controller P1M1<1:0> 2 CCP1M<3:0> 4 PWM1CON CCP1/P1A P1B P1C P1D P1CPIC18F2420/2520/4420/4520 DS39631E-page 150 © 2008 Microchip Technology Inc. 16.4.2 PWM DUTY CYCLE The PWM duty cycle is specified by writing to the CCPR1L register and to the CCP1CON<5:4> bits. Up to 10-bit resolution is available. The CCPR1L contains the eight MSbs and the CCP1CON<5:4> bits contain the two LSbs. This 10-bit value is represented by CCPR1L:CCP1CON<5:4>. The PWM duty cycle is calculated by the following equation. EQUATION 16-2: CCPR1L and CCP1CON<5:4> can be written to at any time, but the duty cycle value is not copied into CCPR1H until a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR1H is a read-only register. The CCPR1H register and a 2-bit internal latch are used to double-buffer the PWM duty cycle. This double-buffering is essential for glitchless PWM operation. When the CCPR1H and 2-bit latch match TMR2, concatenated with an internal 2-bit Q clock or two bits of the TMR2 prescaler, the CCP1 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the following equation. EQUATION 16-3: 16.4.3 PWM OUTPUT CONFIGURATIONS The P1M<1:0> bits in the CCP1CON register allow one of four configurations: • Single Output • Half-Bridge Output • Full-Bridge Output, Forward mode • Full-Bridge Output, Reverse mode The Single Output mode is the standard PWM mode discussed in Section 16.4 “Enhanced PWM Mode”. The Half-Bridge and Full-Bridge Output modes are covered in detail in the sections that follow. The general relationship of the outputs in all configurations is summarized in Figure 16-2 and Figure 16-3. TABLE 16-2: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz PWM Duty Cycle = (CCPR1L:CCP1CON<5:4>) • TOSC • (TMR2 Prescale Value) Note: If the PWM duty cycle value is longer than the PWM period, the CCP1 pin will not be cleared. ( ) PWM Resolution (max) = FOSC FPWM log log(2) bits PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz Timer Prescaler (1, 4, 16) 16 4 1 1 1 1 PR2 Value FFh FFh FFh 3Fh 1Fh 17h Maximum Resolution (bits) 10 10 10 8 7 6.58© 2008 Microchip Technology Inc. DS39631E-page 151 PIC18F2420/2520/4420/4520 FIGURE 16-2: PWM OUTPUT RELATIONSHIPS (ACTIVE-HIGH STATE) FIGURE 16-3: PWM OUTPUT RELATIONSHIPS (ACTIVE-LOW STATE) 0 Period 00 10 01 11 SIGNAL PR2 + 1 CCP1CON<7:6> P1A Modulated P1A Modulated P1B Modulated P1A Active P1B Inactive P1C Inactive P1D Modulated P1A Inactive P1B Modulated P1C Active P1D Inactive Duty Cycle (Single Output) (Half-Bridge) (Full-Bridge, Forward) (Full-Bridge, Reverse) Delay(1) Delay(1) 0 Period 00 10 01 11 SIGNAL PR2 + 1 CCP1CON<7:6> P1A Modulated P1A Modulated P1B Modulated P1A Active P1B Inactive P1C Inactive P1D Modulated P1A Inactive P1B Modulated P1C Active P1D Inactive Duty Cycle (Single Output) (Half-Bridge) (Full-Bridge, Forward) (Full-Bridge, Reverse) Delay(1) Delay(1) Relationships: • Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value) • Duty Cycle = TOSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value) • Delay = 4 * TOSC * (PWM1CON<6:0>) Note 1: Dead-band delay is programmed using the PWM1CON register (see Section 16.4.6 “Programmable Dead-Band Delay”).PIC18F2420/2520/4420/4520 DS39631E-page 152 © 2008 Microchip Technology Inc. 16.4.4 HALF-BRIDGE MODE In the Half-Bridge Output mode, two pins are used as outputs to drive push-pull loads. The PWM output signal is output on the P1A pin, while the complementary PWM output signal is output on the P1B pin (Figure 16-4). This mode can be used for half-bridge applications, as shown in Figure 16-5, or for full-bridge applications where four power switches are being modulated with two PWM signals. In Half-Bridge Output mode, the programmable deadband delay can be used to prevent shoot-through current in half-bridge power devices. The value of bits, PDC<6:0>, sets the number of instruction cycles before the output is driven active. If the value is greater than the duty cycle, the corresponding output remains inactive during the entire cycle. See Section 16.4.6 “Programmable Dead-Band Delay” for more details of the dead-band delay operations. Since the P1A and P1B outputs are multiplexed with the PORTC<2> and PORTD<5> data latches, the TRISC<2> and TRISD<5> bits must be cleared to configure P1A and P1B as outputs. FIGURE 16-4: HALF-BRIDGE PWM OUTPUT FIGURE 16-5: EXAMPLES OF HALF-BRIDGE OUTPUT MODE APPLICATIONS Period Duty Cycle td td (1) P1A(2) P1B(2) td = Dead-Band Delay Period (1) (1) Note 1: At this time, the TMR2 register is equal to the PR2 register. 2: Output signals are shown as active-high. PIC18F4X2X P1A P1B FET Driver FET Driver V+ V- Load + V - + V - FET Driver FET Driver V+ V- Load FET Driver FET Driver PIC18F4X2X P1A P1B Standard Half-Bridge Circuit (“Push-Pull”) Half-Bridge Output Driving a Full-Bridge Circuit© 2008 Microchip Technology Inc. DS39631E-page 153 PIC18F2420/2520/4420/4520 16.4.5 FULL-BRIDGE MODE In Full-Bridge Output mode, four pins are used as outputs; however, only two outputs are active at a time. In the Forward mode, pin P1A is continuously active and pin P1D is modulated. In the Reverse mode, pin P1C is continuously active and pin P1B is modulated. These are illustrated in Figure 16-6. P1A, P1B, P1C and P1D outputs are multiplexed with the PORTC<2> and PORTD<7:5> data latches. The TRISC<2> and TRISD<7:5> bits must be cleared to make the P1A, P1B, P1C and P1D pins outputs. FIGURE 16-6: FULL-BRIDGE PWM OUTPUT Period Duty Cycle P1A(2) P1B(2) P1C(2) P1D(2) Forward Mode (1) Period Duty Cycle P1A(2) P1C(2) P1D(2) P1B(2) Reverse Mode (1) (1) (1) Note 1: At this time, the TMR2 register is equal to the PR2 register. Note 2: Output signal is shown as active-high.PIC18F2420/2520/4420/4520 DS39631E-page 154 © 2008 Microchip Technology Inc. FIGURE 16-7: EXAMPLE OF FULL-BRIDGE OUTPUT MODE APPLICATION 16.4.5.1 Direction Change in Full-Bridge Mode In the Full-Bridge Output mode, the P1M1 bit in the CCP1CON register allows user to control the forward/ reverse direction. When the application firmware changes this direction control bit, the module will assume the new direction on the next PWM cycle. Just before the end of the current PWM period, the modulated outputs (P1B and P1D) are placed in their inactive state, while the unmodulated outputs (P1A and P1C) are switched to drive in the opposite direction. This occurs in a time interval of 4 TOSC * (Timer2 Prescale Value) before the next PWM period begins. The Timer2 prescaler will be either 1, 4 or 16, depending on the value of the T2CKPS<1:0> bits (T2CON<1:0>). During the interval from the switch of the unmodulated outputs to the beginning of the next period, the modulated outputs (P1B and P1D) remain inactive. This relationship is shown in Figure 16-8. Note that in the Full-Bridge Output mode, the CCP1 module does not provide any dead-band delay. In general, since only one output is modulated at all times, dead-band delay is not required. However, there is a situation where a dead-band delay might be required. This situation occurs when both of the following conditions are true: 1. The direction of the PWM output changes when the duty cycle of the output is at or near 100%. 2. The turn-off time of the power switch, including the power device and driver circuit, is greater than the turn-on time. Figure 16-9 shows an example where the PWM direction changes from forward to reverse at a near 100% duty cycle. At time t1, the outputs P1A and P1D become inactive, while output P1C becomes active. In this example, since the turn-off time of the power devices is longer than the turn-on time, a shoot-through current may flow through power devices, QC and QD (see Figure 16-7), for the duration of ‘t’. The same phenomenon will occur to power devices, QA and QB, for PWM direction change from reverse to forward. If changing PWM direction at high duty cycle is required for an application, one of the following requirements must be met: 1. Reduce PWM for a PWM period before changing directions. 2. Use switch drivers that can drive the switches off faster than they can drive them on. Other options to prevent shoot-through current may exist. P1A P1C FET Driver FET Driver V+ V- Load FET Driver FET Driver P1B P1D QA QB QD QC PIC18F4X2X© 2008 Microchip Technology Inc. DS39631E-page 155 PIC18F2420/2520/4420/4520 FIGURE 16-8: PWM DIRECTION CHANGE FIGURE 16-9: PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE DC Period(1) SIGNAL Note 1: The direction bit in the CCP1 Control register (CCP1CON<7>) is written any time during the PWM cycle. 2: When changing directions, the P1A and P1C signals switch before the end of the current PWM cycle at intervals of 4 TOSC, 16 TOSC or 64 TOSC, depending on the Timer2 prescaler value. The modulated P1B and P1D signals are inactive at this time. Period (Note 2) P1A (Active-High) P1B (Active-High) P1C (Active-High) P1D (Active-High) DC Forward Period Reverse Period P1A(1) tON(2) tOFF(3) t = tOFF – tON(2,3) P1B(1) P1C(1) P1D(1) External Switch D(1) Potential Shoot-Through Current(1) Note 1: All signals are shown as active-high. 2: tON is the turn-on delay of power switch, QC, and its driver. 3: tOFF is the turn-off delay of power switch, QD, and its driver. External Switch C(1) t1 DC DCPIC18F2420/2520/4420/4520 DS39631E-page 156 © 2008 Microchip Technology Inc. 16.4.6 PROGRAMMABLE DEAD-BAND DELAY In half-bridge applications where all power switches are modulated at the PWM frequency at all times, the power switches normally require more time to turn off than to turn on. If both the upper and lower power switches are switched at the same time (one turned on and the other turned off), both switches may be on for a short period of time until one switch completely turns off. During this brief interval, a very high current (shootthrough current) may flow through both power switches, shorting the bridge supply. To avoid this potentially destructive shoot-through current from flowing during switching, turning on either of the power switches is normally delayed to allow the other switch to completely turn off. In the Half-Bridge Output mode, a digitally programmable dead-band delay is available to avoid shoot-through current from destroying the bridge power switches. The delay occurs at the signal transition from the nonactive state to the active state (see Figure 16-4 for illustration). Bits, PDC<6:0>, of the PWM1CON register (Register 16-2) set the delay period in terms of microcontroller instruction cycles (TCY or 4 TOSC). These bits are not available on 28-pin devices as the standard CCP module does not support half-bridge operation. 16.4.7 ENHANCED PWM AUTO-SHUTDOWN When the CCP1 is programmed for any of the Enhanced PWM modes, the active output pins may be configured for auto-shutdown. Auto-shutdown immediately places the Enhanced PWM output pins into a defined shutdown state when a shutdown event occurs. A shutdown event can be caused by either of the comparator modules, a low level on the Fault input pin (FLT0) or any combination of these three sources. The comparators may be used to monitor a voltage input proportional to a current being monitored in the bridge circuit. If the voltage exceeds a threshold, the comparator switches state and triggers a shutdown. Alternatively, a low digital signal on FLT0 can also trigger a shutdown. The auto-shutdown feature can be disabled by not selecting any auto-shutdown sources. The autoshutdown sources to be used are selected using the ECCPAS<2:0> bits (ECCP1AS<6:4>). When a shutdown occurs, the output pins are asynchronously placed in their shutdown states, specified by the PSSAC<1:0> and PSSBD<1:0> bits (ECCPAS<2:0>). Each pin pair (P1A/P1C and P1B/ P1D) may be set to drive high, drive low or be tri-stated (not driving). The ECCPASE bit (ECCP1AS<7>) is also set to hold the Enhanced PWM outputs in their shutdown states. The ECCPASE bit is set by hardware when a shutdown event occurs. If automatic restarts are not enabled, the ECCPASE bit is cleared by firmware when the cause of the shutdown clears. If automatic restarts are enabled, the ECCPASE bit is automatically cleared when the cause of the auto-shutdown has cleared. If the ECCPASE bit is set when a PWM period begins, the PWM outputs remain in their shutdown state for that entire PWM period. When the ECCPASE bit is cleared, the PWM outputs will return to normal operation at the beginning of the next PWM period. Note: Programmable dead-band delay is not implemented in 28-pin devices with standard CCP modules. Note: Writing to the ECCPASE bit is disabled while a shutdown condition is active. REGISTER 16-2: PWM1CON: PWM DEAD-BAND DELAY REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 PRSEN PDC6(1) PDC5(1) PDC4(1) PDC3(1) PDC2(1) PDC1(1) PDC0(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 PRSEN: PWM Restart Enable bit 1 = Upon auto-shutdown, the ECCPASE bit clears automatically once the shutdown event goes away; the PWM restarts automatically 0 = Upon auto-shutdown, ECCPASE must be cleared in software to restart the PWM bit 6-0 PDC6:PDC0: PWM Delay Count bits(1) Delay time, in number of FOSC/4 (4 * TOSC) cycles, between the scheduled and actual time for a PWM signal to transition to active. Note 1: Reserved on 28-pin devices; maintain these bits clear.© 2008 Microchip Technology Inc. DS39631E-page 157 PIC18F2420/2520/4420/4520 REGISTER 16-3: ECCP1AS: ECCP AUTO-SHUTDOWN CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1(1) PSSBD0(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 ECCPASE: ECCP Auto-Shutdown Event Status bit 1 = A shutdown event has occurred; ECCP outputs are in shutdown state 0 = ECCP outputs are operating bit 6-4 ECCPAS<2:0>: ECCP Auto-Shutdown Source Select bits 111 = FLT0 or Comparator 1 or Comparator 2 110 = FLT0 or Comparator 2 101 = FLT0 or Comparator 1 100 = FLT0 011 = Either Comparator 1 or 2 010 = Comparator 2 output 001 = Comparator 1 output 000 = Auto-shutdown is disabled bit 3-2 PSSAC<1:0>: Pins A and C Shutdown State Control bits 1x = Pins A and C are tri-state (40/44-pin devices); PWM output is tri-state (28-pin devices) 01 = Drive Pins A and C to ‘1’ 00 = Drive Pins A and C to ‘0’ bit 1-0 PSSBD<1:0>: Pins B and D Shutdown State Control bits(1) 1x = Pins B and D tri-state 01 = Drive Pins B and D to ‘1’ 00 = Drive Pins B and D to ‘0’ Note 1: Reserved on 28-pin devices; maintain these bits clear.PIC18F2420/2520/4420/4520 DS39631E-page 158 © 2008 Microchip Technology Inc. 16.4.7.1 Auto-Shutdown and Automatic Restart The auto-shutdown feature can be configured to allow automatic restarts of the module following a shutdown event. This is enabled by setting the PRSEN bit of the PWM1CON register (PWM1CON<7>). In Shutdown mode with PRSEN = 1 (Figure 16-10), the ECCPASE bit will remain set for as long as the cause of the shutdown continues. When the shutdown condition clears, the ECCPASE bit is cleared. If PRSEN = 0 (Figure 16-11), once a shutdown condition occurs, the ECCPASE bit will remain set until it is cleared by firmware. Once ECCPASE is cleared, the Enhanced PWM will resume at the beginning of the next PWM period. Independent of the PRSEN bit setting, if the autoshutdown source is one of the comparators, the shutdown condition is a level. The ECCPASE bit cannot be cleared as long as the cause of the shutdown persists. The Auto-Shutdown mode can be forced by writing a ‘1’ to the ECCPASE bit. 16.4.8 START-UP CONSIDERATIONS When the ECCP module is used in the PWM mode, the application hardware must use the proper external pullup and/or pull-down resistors on the PWM output pins. When the microcontroller is released from Reset, all of the I/O pins are in the high-impedance state. The external circuits must keep the power switch devices in the OFF state until the microcontroller drives the I/O pins with the proper signal levels or activates the PWM output(s). The CCP1M<1:0> bits (CCP1CON<1:0>) allow the user to choose whether the PWM output signals are active-high or active-low for each pair of PWM output pins (P1A/P1C and P1B/P1D). The PWM output polarities must be selected before the PWM pins are configured as outputs. Changing the polarity configuration while the PWM pins are configured as outputs is not recommended, since it may result in damage to the application circuits. The P1A, P1B, P1C and P1D output latches may not be in the proper states when the PWM module is initialized. Enabling the PWM pins for output at the same time as the ECCP module may cause damage to the application circuit. The ECCP module must be enabled in the proper output mode and complete a full PWM cycle before configuring the PWM pins as outputs. The completion of a full PWM cycle is indicated by the TMR2IF bit being set as the second PWM period begins. FIGURE 16-10: PWM AUTO-SHUTDOWN (PRSEN = 1, AUTO-RESTART ENABLED) FIGURE 16-11: PWM AUTO-SHUTDOWN (PRSEN = 0, AUTO-RESTART DISABLED) Note: Writing to the ECCPASE bit is disabled while a shutdown condition is active. Shutdown PWM ECCPASE bit Activity Event Shutdown Event Occurs Shutdown Event Clears PWM Resumes Normal PWM Start of PWM Period PWM Period Shutdown PWM ECCPASE bit Activity Event Shutdown Event Occurs Shutdown Event Clears PWM Resumes Normal PWM Start of PWM Period ECCPASE Cleared by Firmware PWM Period© 2008 Microchip Technology Inc. DS39631E-page 159 PIC18F2420/2520/4420/4520 16.4.9 SETUP FOR PWM OPERATION The following steps should be taken when configuring the ECCP module for PWM operation: 1. Configure the PWM pins, P1A and P1B (and P1C and P1D, if used), as inputs by setting the corresponding TRIS bits. 2. Set the PWM period by loading the PR2 register. 3. If auto-shutdown is required: • Disable auto-shutdown (ECCPASE = 0) • Configure source (FLT0, Comparator 1 or Comparator 2) • Wait for non-shutdown condition 4. Configure the ECCP module for the desired PWM mode and configuration by loading the CCP1CON register with the appropriate values: • Select one of the available output configurations and direction with the P1M<1:0> bits. • Select the polarities of the PWM output signals with the CCP1M<3:0> bits. 5. Set the PWM duty cycle by loading the CCPR1L register and CCP1CON<5:4> bits. 6. For Half-Bridge Output mode, set the deadband delay by loading PWM1CON<6:0> with the appropriate value. 7. If auto-shutdown operation is required, load the ECCP1AS register: • Select the auto-shutdown sources using the ECCPAS<2:0> bits. • Select the shutdown states of the PWM output pins using the PSSAC<1:0> and PSSBD<1:0> bits. • Set the ECCPASE bit (ECCP1AS<7>). • Configure the comparators using the CMCON register. • Configure the comparator inputs as analog inputs. 8. If auto-restart operation is required, set the PRSEN bit (PWM1CON<7>). 9. Configure and start TMR2: • Clear the TMR2 interrupt flag bit by clearing the TMR2IF bit (PIR1<1>). • Set the TMR2 prescale value by loading the T2CKPS bits (T2CON<1:0>). • Enable Timer2 by setting the TMR2ON bit (T2CON<2>). 10. Enable PWM outputs after a new PWM cycle has started: • Wait until TMRx overflows (TMRxIF bit is set). • Enable the CCP1/P1A, P1B, P1C and/or P1D pin outputs by clearing the respective TRIS bits. • Clear the ECCPASE bit (ECCP1AS<7>). 16.4.10 OPERATION IN POWER-MANAGED MODES In Sleep mode, all clock sources are disabled. Timer2 will not increment and the state of the module will not change. If the ECCP pin is driving a value, it will continue to drive that value. When the device wakes up, it will continue from this state. If Two-Speed Start-ups are enabled, the initial start-up frequency from INTOSC and the postscaler may not be stable immediately. In PRI_IDLE mode, the primary clock will continue to clock the ECCP module without change. In all other power-managed modes, the selected power-managed mode clock will clock Timer2. Other power-managed mode clocks will most likely be different than the primary clock frequency. 16.4.10.1 Operation with Fail-Safe Clock Monitor If the Fail-Safe Clock Monitor is enabled, a clock failure will force the device into the power-managed RC_RUN mode and the OSCFIF bit (PIR2<7>) will be set. The ECCP will then be clocked from the internal oscillator clock source, which may have a different clock frequency than the primary clock. See the previous section for additional details. 16.4.11 EFFECTS OF A RESET Both Power-on Reset and subsequent Resets will force all ports to Input mode and the CCP registers to their Reset states. This forces the Enhanced CCP module to reset to a state compatible with the standard CCP module.PIC18F2420/2520/4420/4520 DS39631E-page 160 © 2008 Microchip Technology Inc. TABLE 16-3: REGISTERS ASSOCIATED WITH ECCP MODULE AND TIMER1 TO TIMER3 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 RCON IPEN SBOREN — RI TO PD POR BOR 48 PIR1 PSPIF ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 TRISB PORTB Data Direction Register 52 TRISC PORTC Data Direction Register 52 TRISD PORTD Data Direction Register 52 TMR1L Timer1 Register Low Byte 50 TMR1H Timer1 Register High Byte 50 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 50 TMR2 Timer2 Register 50 T2CON — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 50 PR2 Timer2 Period Register 50 TMR3L Timer3 Register Low Byte 51 TMR3H Timer3 Register High Byte 51 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 51 CCPR1L Capture/Compare/PWM Register 1 Low Byte 51 CCPR1H Capture/Compare/PWM Register 1 High Byte 51 CCP1CON P1M1(1) P1M0(1) DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 51 ECCP1AS ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1(1) PSSBD0(1) 51 PWM1CON PRSEN PDC6(1) PDC5(1) PDC4(1) PDC3(1) PDC2(1) PDC1(1) PDC0(1) 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during ECCP operation. Note 1: These bits are unimplemented on 28-pin devices; always maintain these bits clear.© 2008 Microchip Technology Inc. DS39631E-page 161 PIC18F2420/2520/4420/4520 17.0 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE 17.1 Master SSP (MSSP) Module Overview The Master Synchronous Serial Port (MSSP) module is a serial interface, useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D Converters, etc. The MSSP module can operate in one of two modes: • Serial Peripheral Interface (SPI) • Inter-Integrated Circuit (I2C) - Full Master mode - Slave mode (with general address call) The I2C interface supports the following modes in hardware: • Master mode • Multi-Master mode • Slave mode 17.2 Control Registers The MSSP module has three associated registers. These include a status register (SSPSTAT) and two control registers (SSPCON1 and SSPCON2). The use of these registers and their individual configuration bits differ significantly depending on whether the MSSP module is operated in SPI or I2C mode. Additional details are provided under the individual sections. 17.3 SPI Mode The SPI mode allows 8 bits of data to be synchronously transmitted and received simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: • Serial Data Out (SDO) – RC5/SDO • Serial Data In (SDI) – RC4/SDI/SDA • Serial Clock (SCK) – RC3/SCK/SCL Additionally, a fourth pin may be used when in a Slave mode of operation: • Slave Select (SS) – RA5/SS Figure 17-1 shows the block diagram of the MSSP module when operating in SPI mode. FIGURE 17-1: MSSP BLOCK DIAGRAM (SPI MODE) ( ) Read Write Internal Data Bus SSPSR reg SSPM<3:0> bit 0 Shift Clock SS Control Enable Edge Select Clock Select TMR2 Output Prescaler TOSC 4, 16, 64 2 Edge Select 2 4 Data to TX/RX in SSPSR TRIS bit 2 SMP:CKE RC5/SDO SSPBUF reg RC4/SDI/SDA RA5/AN4/SS/ RC3/SCK/ SCL HLVDIN/C2OUTPIC18F2420/2520/4420/4520 DS39631E-page 162 © 2008 Microchip Technology Inc. 17.3.1 REGISTERS The MSSP module has four registers for SPI mode operation. These are: • MSSP Control Register 1 (SSPCON1) • MSSP Status Register (SSPSTAT) • Serial Receive/Transmit Buffer Register (SSPBUF) • MSSP Shift Register (SSPSR) – Not directly accessible SSPCON1 and SSPSTAT are the control and status registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper two bits of the SSPSTAT are read/write. SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. In receive operations, SSPSR and SSPBUF together create a double-buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. During transmission, the SSPBUF is not doublebuffered. A write to SSPBUF will write to both SSPBUF and SSPSR. REGISTER 17-1: SSPSTAT: MSSP STATUS REGISTER (SPI MODE) R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 SMP CKE(1) D/A P S R/W UA BF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 SMP: Sample bit SPI Master mode: 1 = Input data sampled at end of data output time 0 = Input data sampled at middle of data output time SPI Slave mode: SMP must be cleared when SPI is used in Slave mode. bit 6 CKE: SPI Clock Select bit(1) 1 = Transmit occurs on transition from active to Idle clock state 0 = Transmit occurs on transition from Idle to active clock state bit 5 D/A: Data/Address bit Used in I2C™ mode only. bit 4 P: Stop bit Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared. bit 3 S: Start bit Used in I2C mode only. bit 2 R/W: Read/Write Information bit Used in I2C mode only. bit 1 UA: Update Address bit Used in I2C mode only. bit 0 BF: Buffer Full Status bit (Receive mode only) 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty Note 1: Polarity of clock state is set by the CKP bit (SSPCON1<4>).© 2008 Microchip Technology Inc. DS39631E-page 163 PIC18F2420/2520/4420/4520 REGISTER 17-2: SSPCON1: MSSP CONTROL REGISTER 1 (SPI MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV(1) SSPEN(2) CKP SSPM3(3) SSPM2(3) SSPM1(3) SSPM0(3) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 WCOL: Write Collision Detect bit 1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision bit 6 SSPOV: Receive Overflow Indicator bit(1) SPI Slave mode: 1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode. The user must read the SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software). 0 = No overflow bit 5 SSPEN: Master Synchronous Serial Port Enable bit(2) 1 = Enables serial port and configures SCK, SDO, SDI and SS as serial port pins 0 = Disables serial port and configures these pins as I/O port pins bit 4 CKP: Clock Polarity Select bit 1 = Idle state for clock is a high level 0 = Idle state for clock is a low level bit 3-0 SSPM<3:0>: Master Synchronous Serial Port Mode Select bits(3) 0101 = SPI Slave mode, clock = SCK pin; SS pin control disabled; SS can be used as I/O pin 0100 = SPI Slave mode, clock = SCK pin; SS pin control enabled 0011 = SPI Master mode, clock = TMR2 output/2 0010 = SPI Master mode, clock = FOSC/64 0001 = SPI Master mode, clock = FOSC/16 0000 = SPI Master mode, clock = FOSC/4 Note 1: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the SSPBUF register. 2: When enabled, these pins must be properly configured as input or output. 3: Bit combinations not specifically listed here are either reserved or implemented in I2C™ mode only.PIC18F2420/2520/4420/4520 DS39631E-page 164 © 2008 Microchip Technology Inc. 17.3.2 OPERATION When initializing the SPI, several options need to be specified. This is done by programming the appropriate control bits (SSPCON1<5:0> and SSPSTAT<7:6>). These control bits allow the following to be specified: • Master mode (SCK is the clock output) • Slave mode (SCK is the clock input) • Clock Polarity (Idle state of SCK) • Data Input Sample Phase (middle or end of data output time) • Clock Edge (output data on rising/falling edge of SCK) • Clock Rate (Master mode only) • Slave Select mode (Slave mode only) The MSSP consists of a transmit/receive shift register (SSPSR) and a buffer register (SSPBUF). The SSPSR shifts the data in and out of the device, MSb first. The SSPBUF holds the data that was written to the SSPSR until the received data is ready. Once the 8 bits of data have been received, that byte is moved to the SSPBUF register. Then, the Buffer Full detect bit, BF (SSPSTAT<0>) and the interrupt flag bit, SSPIF, are set. This double-buffering of the received data (SSPBUF) allows the next byte to start reception before reading the data that was just received. Any write to the SSPBUF register during transmission/reception of data will be ignored and the write collision detect bit, WCOL (SSPCON1<7>), will be set. User software must clear the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed successfully. When the application software is expecting to receive valid data, the SSPBUF should be read before the next byte of data to transfer is written to the SSPBUF. The Buffer Full bit, BF (SSPSTAT<0>), indicates when SSPBUF has been loaded with the received data (transmission is complete). When the SSPBUF is read, the BF bit is cleared. This data may be irrelevant if the SPI is only a transmitter. Generally, the MSSP interrupt is used to determine when the transmission/reception has completed. The SSPBUF must be read and/or written. If the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. Example 17-1 shows the loading of the SSPBUF (SSPSR) for data transmission. The SSPSR is not directly readable or writable and can only be accessed by addressing the SSPBUF register. Additionally, the MSSP Status register (SSPSTAT) indicates the various status conditions. EXAMPLE 17-1: LOADING THE SSPBUF (SSPSR) REGISTER Note: The SSPBUF register cannot be used with read-modify-write instructions such as BCF, BTFSC and COMF, etc. LOOP BTFSS SSPSTAT, BF ;Has data been received (transmit complete)? BRA LOOP ;No MOVF SSPBUF, W ;WREG reg = contents of SSPBUF MOVWF RXDATA ;Save in user RAM, if data is meaningful MOVF TXDATA, W ;W reg = contents of TXDATA MOVWF SSPBUF ;New data to xmit Note: To avoid lost data in Master mode, a read of the SSPBUF must be performed to clear the Buffer Full (BF) detect bit (SSPSTAT<0>) between each transmission.© 2008 Microchip Technology Inc. DS39631E-page 165 PIC18F2420/2520/4420/4520 17.3.3 ENABLING SPI I/O To enable the serial port, MSSP Enable bit, SSPEN (SSPCON1<5>), must be set. To reset or reconfigure SPI mode, clear the SSPEN bit, reinitialize the SSPCON registers and then set the SSPEN bit. This configures the SDI, SDO, SCK and SS pins as serial port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the TRIS register) appropriately programmed as follows: • SDI is automatically controlled by the SPI module • SDO must have TRISC<5> bit cleared • SCK (Master mode) must have TRISC<3> bit cleared • SCK (Slave mode) must have TRISC<3> bit set • SS must have TRISA<5> bit set Any serial port function that is not desired may be overridden by programming the corresponding data direction (TRIS) register to the opposite value. 17.3.4 TYPICAL CONNECTION Figure 17-2 shows a typical connection between two microcontrollers. The master controller (Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both shift registers on their programmed clock edge and latched on the opposite edge of the clock. Both processors should be programmed to the same Clock Polarity (CKP), then both controllers would send and receive data at the same time. Whether the data is meaningful (or dummy data) depends on the application software. This leads to three scenarios for data transmission: • Master sends data – Slave sends dummy data • Master sends data – Slave sends data • Master sends dummy data – Slave sends data FIGURE 17-2: SPI MASTER/SLAVE CONNECTION Serial Input Buffer (SSPBUF) Shift Register (SSPSR) MSb LSb SDO SDI PROCESSOR 1 SCK SPI Master SSPM<3:0> = 00xxb Serial Input Buffer (SSPBUF) Shift Register (SSPSR) MSb LSb SDI SDO PROCESSOR 2 SCK SPI Slave SSPM<3:0> = 010xb Serial ClockPIC18F2420/2520/4420/4520 DS39631E-page 166 © 2008 Microchip Technology Inc. 17.3.5 MASTER MODE The master can initiate the data transfer at any time because it controls the SCK. The master determines when the slave (Processor 2, Figure 17-2) is to broadcast data by the software protocol. In Master mode, the data is transmitted/received as soon as the SSPBUF register is written to. If the SPI is only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register will continue to shift in the signal present on the SDI pin at the programmed clock rate. As each byte is received, it will be loaded into the SSPBUF register as if a normal received byte (interrupts and status bits appropriately set). This could be useful in receiver applications as a “Line Activity Monitor” mode. The clock polarity is selected by appropriately programming the CKP bit (SSPCON1<4>). This, then, would give waveforms for SPI communication as shown in Figure 17-3, Figure 17-5 and Figure 17-6, where the MSB is transmitted first. In Master mode, the SPI clock rate (bit rate) is user-programmable to be one of the following: • FOSC/4 (or TCY) • FOSC/16 (or 4 • TCY) • FOSC/64 (or 16 • TCY) • Timer2 output/2 This allows a maximum data rate (at 40 MHz) of 10.00 Mbps. Figure 17-3 shows the waveforms for Master mode. When the CKE bit is set, the SDO data is valid before there is a clock edge on SCK. The change of the input sample is shown based on the state of the SMP bit. The time when the SSPBUF is loaded with the received data is shown. FIGURE 17-3: SPI MODE WAVEFORM (MASTER MODE) SCK (CKP = 0 SCK (CKP = 1 SCK (CKP = 0 SCK (CKP = 1 4 Clock Modes Input Sample Input Sample SDI bit 7 bit 0 SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 7 SDI SSPIF (SMP = 1) (SMP = 0) (SMP = 1) CKE = 1) CKE = 0) CKE = 1) CKE = 0) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 (CKE = 0) (CKE = 1) Next Q4 Cycle after Q2↓ bit 0© 2008 Microchip Technology Inc. DS39631E-page 167 PIC18F2420/2520/4420/4520 17.3.6 SLAVE MODE In Slave mode, the data is transmitted and received as the external clock pulses appear on SCK. When the last bit is latched, the SSPIF interrupt flag bit is set. Before enabling the module in SPI Slave mode, the clock line must match the proper Idle state. The clock line can be observed by reading the SCK pin. The Idle state is determined by the CKP bit (SSPCON1<4>). While in Slave mode, the external clock is supplied by the external clock source on the SCK pin. This external clock must meet the minimum high and low times as specified in the electrical specifications. While in Sleep mode, the slave can transmit/receive data. When a byte is received, the device will wake-up from Sleep. 17.3.7 SLAVE SELECT SYNCHRONIZATION The SS pin allows a Synchronous Slave mode. The SPI must be in Slave mode with SS pin control enabled (SSPCON1<3:0> = 04h). The pin must not be driven low for the SS pin to function as an input. The data latch must be high. When the SS pin is low, transmission and reception are enabled and the SDO pin is driven. When the SS pin goes high, the SDO pin is no longer driven, even if in the middle of a transmitted byte and becomes a floating output. External pull-up/pull-down resistors may be desirable depending on the application. When the SPI module resets, the bit counter is forced to ‘0’. This can be done by either forcing the SS pin to a high level or clearing the SSPEN bit. To emulate two-wire communication, the SDO pin can be connected to the SDI pin. When the SPI needs to operate as a receiver, the SDO pin can be configured as an input. This disables transmissions from the SDO. The SDI can always be left as an input (SDI function) since it cannot create a bus conflict. FIGURE 17-4: SLAVE SYNCHRONIZATION WAVEFORM Note 1: When the SPI is in Slave mode with SS pin control enabled (SSPCON<3:0> = 0100), the SPI module will reset if the SS pin is set to VDD. 2: If the SPI is used in Slave mode with CKE set, then the SS pin control must be enabled. SCK (CKP = 1 SCK (CKP = 0 Input Sample SDI bit 7 SDO bit 7 bit 6 bit 7 SSPIF Interrupt (SMP = 0) CKE = 0) CKE = 0) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SS Flag bit 0 bit 7 bit 0 Next Q4 Cycle after Q2↓PIC18F2420/2520/4420/4520 DS39631E-page 168 © 2008 Microchip Technology Inc. FIGURE 17-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0) FIGURE 17-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1) SCK (CKP = 1 SCK (CKP = 0 Input Sample SDI bit 7 SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 SSPIF Interrupt (SMP = 0) CKE = 0) CKE = 0) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SS Flag Optional Next Q4 Cycle after Q2↓ bit 0 SCK (CKP = 1 SCK (CKP = 0 Input Sample SDI bit 7 bit 0 SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 SSPIF Interrupt (SMP = 0) CKE = 1) CKE = 1) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SS Flag Not Optional Next Q4 Cycle after Q2↓© 2008 Microchip Technology Inc. DS39631E-page 169 PIC18F2420/2520/4420/4520 17.3.8 OPERATION IN POWER-MANAGED MODES In SPI Master mode, module clocks may be operating at a different speed than when in full-power mode; in the case of Sleep mode, all clocks are halted. In most Idle modes, a clock is provided to the peripherals. That clock should be from the primary clock source, the secondary clock (Timer1 oscillator at 32.768 kHz) or the INTOSC source. See Section 2.7 “Clock Sources and Oscillator Switching” for additional information. In most cases, the speed that the master clocks SPI data is not important; however, this should be evaluated for each system. If MSSP interrupts are enabled, they can wake the controller from Sleep mode, or one of the Idle modes, when the master completes sending data. If an exit from Sleep or Idle mode is not desired, MSSP interrupts should be disabled. If the Sleep mode is selected, all module clocks are halted and the transmission/reception will remain in that state until the devices wakes. After the device returns to Run mode, the module will resume transmitting and receiving data. In SPI Slave mode, the SPI Transmit/Receive Shift register operates asynchronously to the device. This allows the device to be placed in any power-managed mode and data to be shifted into the SPI Transmit/ Receive Shift register. When all 8 bits have been received, the MSSP interrupt flag bit will be set, and if enabled, will wake the device. 17.3.9 EFFECTS OF A RESET A Reset disables the MSSP module and terminates the current transfer. 17.3.10 BUS MODE COMPATIBILITY Table 17-1 shows the compatibility between the standard SPI modes and the states of the CKP and CKE control bits. TABLE 17-1: SPI BUS MODES There is also an SMP bit which controls when the data is sampled. TABLE 17-2: REGISTERS ASSOCIATED WITH SPI OPERATION Standard SPI Mode Terminology Control Bits State CKP CKE 0, 0 0 1 0, 1 0 0 1, 0 1 1 1, 1 1 0 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 TRISA TRISA7(2) TRISA6(2) PORTA Data Direction Register 52 TRISC PORTC Data Direction Register 52 SSPBUF MSSP Receive Buffer/Transmit Register 50 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 50 SSPSTAT SMP CKE D/A P S R/W UA BF 50 Legend: Shaded cells are not used by the MSSP in SPI mode. Note 1: These bits are unimplemented in 28-pin devices; always maintain these bits clear. 2: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’.PIC18F2420/2520/4420/4520 DS39631E-page 170 © 2008 Microchip Technology Inc. 17.4 I2C Mode The MSSP module in I2C mode fully implements all master and slave functions (including general call support) and provides interrupts on Start and Stop bits in hardware to determine a free bus (multi-master function). The MSSP module implements the standard mode specifications, as well as 7-Bit and 10-Bit Addressing modes. Two pins are used for data transfer: • Serial clock (SCL) – RC3/SCK/SCL • Serial data (SDA) – RC4/SDI/SDA The user must configure these pins as inputs or outputs through the TRISC<4:3> bits. FIGURE 17-7: MSSP BLOCK DIAGRAM (I2C MODE) 17.4.1 REGISTERS The MSSP module has six registers for I2C operation. These are: • MSSP Control Register 1 (SSPCON1) • MSSP Control Register 2 (SSPCON2) • MSSP Status Register (SSPSTAT) • Serial Receive/Transmit Buffer Register (SSPBUF) • MSSP Shift Register (SSPSR) – Not directly accessible • MSSP Address Register (SSPADD) SSPCON1, SSPCON2 and SSPSTAT are the control and status registers in I2C mode operation. The SSPCON1 and SSPCON2 registers are readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper two bits of the SSPSTAT are read/write. SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. SSPADD register holds the slave device address when the MSSP is configured in I2C Slave mode. When the MSSP is configured in Master mode, the lower seven bits of SSPADD act as the Baud Rate Generator reload value. In receive operations, SSPSR and SSPBUF together create a double-buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. During transmission, the SSPBUF is not doublebuffered. A write to SSPBUF will write to both SSPBUF and SSPSR. Read Write SSPSR reg Match Detect SSPADD reg Start and Stop bit Detect SSPBUF reg Internal Data Bus Addr Match Set, Reset S, P bits (SSPSTAT reg) RC3/SCK/SCL RC4/SDI/ Shift Clock MSb SDA LSb© 2008 Microchip Technology Inc. DS39631E-page 171 PIC18F2420/2520/4420/4520 REGISTER 17-3: SSPSTAT: MSSP STATUS REGISTER (I2C™ MODE) R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 SMP CKE D/A P(1) S(1) R/W(2,3) UA BF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 SMP: Slew Rate Control bit In Master or Slave mode: 1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz) 0 = Slew rate control enabled for High-Speed mode (400 kHz) bit 6 CKE: SMBus Select bit In Master or Slave mode: 1 = Enable SMBus specific inputs 0 = Disable SMBus specific inputs bit 5 D/A: Data/Address bit In Master mode: Reserved. In Slave mode: 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address bit 4 P: Stop bit(1) 1 = Indicates that a Stop bit has been detected last 0 = Stop bit was not detected last bit 3 S: Start bit(1) 1 = Indicates that a Start bit has been detected last 0 = Start bit was not detected last bit 2 R/W: Read/Write Information bit (I2C mode only)(2,3) In Slave mode: 1 = Read 0 = Write In Master mode: 1 = Transmit is in progress 0 = Transmit is not in progress bit 1 UA: Update Address bit (10-Bit Slave mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated bit 0 BF: Buffer Full Status bit In Transmit mode: 1 = SSPBUF is full 0 = SSPBUF is empty In Receive mode: 1 = SSPBUF is full (does not include the ACK and Stop bits) 0 = SSPBUF is empty (does not include the ACK and Stop bits) Note 1: This bit is cleared on Reset and when SSPEN is cleared. 2: This bit holds the R/W bit information following the last address match. This bit is only valid from the address match to the next Start bit, Stop bit or not ACK bit. 3: ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is in Active mode.PIC18F2420/2520/4420/4520 DS39631E-page 172 © 2008 Microchip Technology Inc. REGISTER 17-4: SSPCON1: MSSP CONTROL REGISTER 1 (I2C™ MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV SSPEN(1) CKP SSPM3 SSPM2 SSPM1 SSPM0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 WCOL: Write Collision Detect bit In Master Transmit mode: 1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for a transmission to be started (must be cleared in software) 0 = No collision In Slave Transmit mode: 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision In Receive mode (Master or Slave modes): This is a “don’t care” bit. bit 6 SSPOV: Receive Overflow Indicator bit In Receive mode: 1 = A byte is received while the SSPBUF register is still holding the previous byte (must be cleared in software) 0 = No overflow In Transmit mode: This is a “don’t care” bit in Transmit mode. bit 5 SSPEN: Master Synchronous Serial Port Enable bit(1) 1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins 0 = Disables serial port and configures these pins as I/O port pins bit 4 CKP: SCK Release Control bit In Slave mode: 1 = Releases clock 0 = Holds clock low (clock stretch), used to ensure data setup time In Master mode: Unused in this mode. bit 3-0 SSPM<3:0>: Master Synchronous Serial Port Mode Select bits(2) 1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled 1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled 1011 = I2C Firmware Controlled Master mode (Slave Idle) 1000 = I2C Master mode, clock = FOSC/(4 * (SSPADD + 1)) 0111 = I2C Slave mode, 10-bit address 0110 = I2C Slave mode, 7-bit address Bit combinations not specifically listed here are either reserved or implemented in SPI mode only. Note 1: When enabled, the SDA and SCL pins must be properly configured as inputs or outputs.© 2008 Microchip Technology Inc. DS39631E-page 173 PIC18F2420/2520/4420/4520 REGISTER 17-5: SSPCON2: MSSP CONTROL REGISTER 2 (I2C™ MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 GCEN ACKSTAT ACKDT(2) ACKEN(1) RCEN(1) PEN(1) RSEN(1) SEN(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 GCEN: General Call Enable bit (Slave mode only) 1 = Enables interrupt when a general call address (0000h) is received in the SSPSR 0 = General call address disabled. bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only) 1 = Acknowledge was not received from slave 0 = Acknowledge was received from slave bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only)(2) 1 = Not Acknowledge 0 = Acknowledge bit 4 ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)(1) 1 = Initiates Acknowledge sequence on SDA and SCL pins and transmit ACKDT data bit. Automatically cleared by hardware. 0 = Acknowledge sequence Idle bit 3 RCEN: Receive Enable bit (Master mode only)(1) 1 = Enables Receive mode for I2C 0 = Receive Idle bit 2 PEN: Stop Condition Enable bit (Master mode only)(1) 1 = Initiates Stop condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Stop condition Idle bit 1 RSEN: Repeated Start Condition Enable bit (Master mode only)(1) 1 = Initiates Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated Start condition Idle bit 0 SEN: Start Condition Enable/Stretch Enable bit(1) In Master mode: 1 = Initiates Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Start condition Idle In Slave mode: 1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled) 0 = Clock stretching is disabled Note 1: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the Idle mode, these bits may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled). 2: Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive.PIC18F2420/2520/4420/4520 DS39631E-page 174 © 2008 Microchip Technology Inc. 17.4.2 OPERATION The MSSP module functions are enabled by setting the MSSP Enable bit, SSPEN (SSPCON1<5>). The SSPCON1 register allows control of the I2C operation. Four mode selection bits (SSPCON1<3:0>) allow one of the following I2C modes to be selected: • I2C Master mode, clock = (FOSC/4) x (SSPADD + 1) • I2C Slave mode (7-bit addressing) • I2C Slave mode (10-bit addressing) • I2C Slave mode (7-bit addressing) with Start and Stop bit interrupts enabled • I2C Slave mode (10-bit addressing) with Start and Stop bit interrupts enabled • I2C Firmware Controlled Master mode, slave is Idle Selection of any I2C mode, with the SSPEN bit set, forces the SCL and SDA pins to be open-drain, provided these pins are programmed to inputs by setting the appropriate TRISC bits. To ensure proper operation of the module, pull-up resistors must be provided externally to the SCL and SDA pins. 17.4.3 SLAVE MODE In Slave mode, the SCL and SDA pins must be configured as inputs (TRISC<4:3> set). The MSSP module will override the input state with the output data when required (slave-transmitter). The I2C Slave mode hardware will always generate an interrupt on an address match. Through the mode select bits, the user can also choose to interrupt on Start and Stop bits When an address is matched, or the data transfer after an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse and load the SSPBUF register with the received value currently in the SSPSR register. Any combination of the following conditions will cause the MSSP module not to give this ACK pulse: • The Buffer Full bit, BF (SSPSTAT<0>), was set before the transfer was received. • The overflow bit, SSPOV (SSPCON2<6>), was set before the transfer was received. In this case, the SSPSR register value is not loaded into the SSPBUF, but bit, SSPIF (PIR1<3>), is set. The BF bit is cleared by reading the SSPBUF register, while bit SSPOV is cleared through software. The SCL clock input must have a minimum high and low for proper operation. The high and low times of the I 2C specification, as well as the requirement of the MSSP module, are shown in timing parameter 100 and parameter 101. 17.4.3.1 Addressing Once the MSSP module has been enabled, it waits for a Start condition to occur. Following the Start condition, the 8 bits are shifted into the SSPSR register. All incoming bits are sampled with the rising edge of the clock (SCL) line. The value of register SSPSR<7:1> is compared to the value of the SSPADD register. The address is compared on the falling edge of the eighth clock (SCL) pulse. If the addresses match and the BF and SSPOV bits are clear, the following events occur: 1. The SSPSR register value is loaded into the SSPBUF register. 2. The Buffer Full bit, BF, is set. 3. An ACK pulse is generated. 4. MSSP Interrupt Flag bit, SSPIF (PIR1<3>), is set (interrupt is generated, if enabled) on the falling edge of the ninth SCL pulse. In 10-Bit Addressing mode, two address bytes need to be received by the slave. The five Most Significant bits (MSbs) of the first address byte specify if this is a 10-bit address. Bit, R/W (SSPSTAT<2>), must specify a write so the slave device will receive the second address byte. For a 10-bit address, the first byte would equal ‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the two MSbs of the address. The sequence of events for 10-Bit Addressing mode is as follows, with steps 7 through 9 for the slave-transmitter: 1. Receive first (high) byte of address (bits, SSPIF, BF and UA (SSPSTAT<1>), are set). 2. Update the SSPADD register with second (low) byte of address (clears UA bit and releases the SCL line). 3. Read the SSPBUF register (clears BF bit) and clear flag bit, SSPIF. 4. Receive second (low) byte of address (bits, SSPIF, BF and UA, are set). 5. Update the SSPADD register with the first (high) byte of address. If match releases SCL line, this will clear bit, UA. 6. Read the SSPBUF register (clears BF bit) and clear flag bit, SSPIF. 7. Receive Repeated Start condition. 8. Receive first (high) byte of address (bits, SSPIF and BF, are set). 9. Read the SSPBUF register (clears BF bit) and clear flag bit, SSPIF.© 2008 Microchip Technology Inc. DS39631E-page 175 PIC18F2420/2520/4420/4520 17.4.3.2 Reception When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into the SSPBUF register and the SDA line is held low (ACK). When the address byte overflow condition exists, then the no Acknowledge (ACK) pulse is given. An overflow condition is defined as either bit, BF (SSPSTAT<0>), is set, or bit, SSPOV (SSPCON1<6>), is set. An MSSP interrupt is generated for each data transfer byte. Flag bit, SSPIF (PIR1<3>), must be cleared in software. The SSPSTAT register is used to determine the status of the byte. If SEN is enabled (SSPCON2<0> = 1), RC3/SCK/SCL will be held low (clock stretch) following each data transfer. The clock must be released by setting bit, CKP (SSPCON<4>). See Section 17.4.4 “Clock Stretching” for more details. 17.4.3.3 Transmission When the R/W bit of the incoming address byte is set and an address match occurs, the R/W bit of the SSPSTAT register is set. The received address is loaded into the SSPBUF register. The ACK pulse will be sent on the ninth bit and the RC3/SCK/SCL pin is held low regardless of SEN (see Section 17.4.4 “Clock Stretching” for more detail). By stretching the clock, the master will be unable to assert another clock pulse until the slave is done preparing the transmit data. The transmit data must be loaded into the SSPBUF register which also loads the SSPSR register. Then the RC3/SCK/SCL pin should be enabled by setting bit, CKP (SSPCON1<4>). The eight data bits are shifted out on the falling edge of the SCL input. This ensures that the SDA signal is valid during the SCL high time (Figure 17-9). The ACK pulse from the master-receiver is latched on the rising edge of the ninth SCL input pulse. If the SDA line is high (not ACK), then the data transfer is complete. In this case, when the ACK is latched by the slave, the slave logic is reset (resets SSPSTAT register) and the slave monitors for another occurrence of the Start bit. If the SDA line was low (ACK), the next transmit data must be loaded into the SSPBUF register. Again, the RC3/SCK/SCL pin must be enabled by setting bit, CKP. An MSSP interrupt is generated for each data transfer byte. The SSPIF bit must be cleared in software and the SSPSTAT register is used to determine the status of the byte. The SSPIF bit is set on the falling edge of the ninth clock pulse.PIC18F2420/2520/4420/4520 DS39631E-page 176 © 2008 Microchip Technology Inc. FIGURE 17-8: I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESSING) SDA SCL SSPIF BF (SSPSTAT<0>) SSPOV (SSPCON1<6>) S 1 2 34 56 7 89 1 2 34 5 67 89 1 23 45 7 89 P A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0 ACK Receiving Data ACK Receiving Data R/W = 0 ACK Receiving Address Cleared in software SSPBUF is read Bus master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. D2 6 (PIR1<3>) CKP (SSPCON1<4>) (CKP does not reset to ‘0’ when SEN = 0)© 2008 Microchip Technology Inc. DS39631E-page 177 PIC18F2420/2520/4420/4520 FIGURE 17-9: I2C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESSING) SDA SCL SSPIF (PIR1<3>) BF (SSPSTAT<0>) A6 A5 A4 A3 A2 A1 D6 D5 D4 D3 D2 D1 D0 1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9 SSPBUF is written in software Cleared in software Data in sampled S ACK Transmitting Data R/W = 1 ACK Receiving Address A7 D7 9 1 D6 D5 D4 D3 D2 D1 D0 2 3 4 5 6 7 8 9 SSPBUF is written in software Cleared in software From SSPIF ISR Transmitting Data D7 1 CKP P ACK CKP is set in software CKP is set in software SCL held low while CPU responds to SSPIF Clear by reading From SSPIF ISRPIC18F2420/2520/4420/4520 DS39631E-page 178 © 2008 Microchip Technology Inc. FIGURE 17-10: I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESSING) SDA SCL SSPIF BF (SSPSTAT<0>) S 1234 567 89 12 345 67 89 1 2345 7 89 P 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D1 D0 Receive Data Byte ACK R/W = 0 ACK Receive First Byte of Address Cleared in software D2 6 (PIR1<3>) Cleared in software Receive Second Byte of Address Cleared by hardware when SSPADD is updated with low byte of address UA (SSPSTAT<1>) Clock is held low until update of SSPADD has taken place UA is set indicating that the SSPADD needs to be updated UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag ACK CKP (SSPCON1<4>) D7 D6 D5 D4 D3 D1 D0 12345 789 Receive Data Byte Bus master terminates transfer D2 6 ACK Cleared in software Cleared in software SSPOV (SSPCON1<6>) SSPOV is set because SSPBUF is still full. ACK is not sent. (CKP does not reset to ‘0’ when SEN = 0) Clock is held low until update of SSPADD has taken place© 2008 Microchip Technology Inc. DS39631E-page 179 PIC18F2420/2520/4420/4520 FIGURE 17-11: I2C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESSING) SDA SCL SSPIF BF (SSPSTAT<0>) S 1234 5 6789 1 23 45 678 9 12345 7 89 P 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 1 1 1 1 0 A8 R/W=1 ACK ACK R/W = 0 ACK Receive First Byte of Address Cleared in software Bus master terminates transfer A9 6 (PIR1<3>) Receive Second Byte of Address Cleared by hardware when SSPADD is updated with low byte of address UA (SSPSTAT<1>) Clock is held low until update of SSPADD has taken place UA is set indicating that the SSPADD needs to be updated UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address. SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag Receive First Byte of Address D7 D6 D5 D4 D3 D1 12345 789 ACK D2 6 Transmitting Data Byte D0 Dummy read of SSPBUF to clear BF flag Sr Cleared in software Write of SSPBUF initiates transmit Cleared in software Completion of clears BF flag CKP (SSPCON1<4>) CKP is set in software CKP is automatically cleared in hardware, holding SCL low Clock is held low until update of SSPADD has taken place data transmission Clock is held low until CKP is set to ‘1’ BF flag is clear at the end of the third address sequencePIC18F2420/2520/4420/4520 DS39631E-page 180 © 2008 Microchip Technology Inc. 17.4.4 CLOCK STRETCHING Both 7-Bit and 10-Bit Slave modes implement automatic clock stretching during a transmit sequence. The SEN bit (SSPCON2<0>) allows clock stretching to be enabled during receives. Setting SEN will cause the SCL pin to be held low at the end of each data receive sequence. 17.4.4.1 Clock Stretching for 7-Bit Slave Receive Mode (SEN = 1) In 7-Bit Slave Receive mode, on the falling edge of the ninth clock at the end of the ACK sequence if the BF bit is set, the CKP bit in the SSPCON1 register is automatically cleared, forcing the SCL output to be held low. The CKP being cleared to ‘0’ will assert the SCL line low. The CKP bit must be set in the user’s Interrupt Service Routine (ISR) before reception is allowed to continue. By holding the SCL line low, the user has time to service the ISR and read the contents of the SSPBUF before the master device can initiate another receive sequence. This will prevent buffer overruns from occurring (see Figure 17-13). 17.4.4.2 Clock Stretching for 10-Bit Slave Receive Mode (SEN = 1) In 10-Bit Slave Receive mode during the address sequence, clock stretching automatically takes place but CKP is not cleared. During this time, if the UA bit is set after the ninth clock, clock stretching is initiated. The UA bit is set after receiving the upper byte of the 10-bit address and following the receive of the second byte of the 10-bit address with the R/W bit cleared to ‘0’. The release of the clock line occurs upon updating SSPADD. Clock stretching will occur on each data receive sequence as described in 7-bit mode. 17.4.4.3 Clock Stretching for 7-Bit Slave Transmit Mode 7-Bit Slave Transmit mode implements clock stretching by clearing the CKP bit after the falling edge of the ninth clock if the BF bit is clear. This occurs regardless of the state of the SEN bit. The user’s ISR must set the CKP bit before transmission is allowed to continue. By holding the SCL line low, the user has time to service the ISR and load the contents of the SSPBUF before the master device can initiate another transmit sequence (see Figure 17-9). 17.4.4.4 Clock Stretching for 10-Bit Slave Transmit Mode In 10-Bit Slave Transmit mode, clock stretching is controlled during the first two address sequences by the state of the UA bit, just as it is in 10-Bit Slave Receive mode. The first two addresses are followed by a third address sequence which contains the high-order bits of the 10-bit address and the R/W bit set to ‘1’. After the third address sequence is performed, the UA bit is not set, the module is now configured in Transmit mode and clock stretching is controlled by the BF flag as in 7-Bit Slave Transmit mode (see Figure 17-11). Note 1: If the user reads the contents of the SSPBUF before the falling edge of the ninth clock, thus clearing the BF bit, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software regardless of the state of the BF bit. The user should be careful to clear the BF bit in the ISR before the next receive sequence in order to prevent an overflow condition. Note: If the user polls the UA bit and clears it by updating the SSPADD register before the falling edge of the ninth clock occurs and if the user hasn’t cleared the BF bit by reading the SSPBUF register before that time, then the CKP bit will still NOT be asserted low. Clock stretching on the basis of the state of the BF bit only occurs during a data sequence, not an address sequence. Note 1: If the user loads the contents of SSPBUF, setting the BF bit before the falling edge of the ninth clock, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software regardless of the state of the BF bit.© 2008 Microchip Technology Inc. DS39631E-page 181 PIC18F2420/2520/4420/4520 17.4.4.5 Clock Synchronization and the CKP bit When the CKP bit is cleared, the SCL output is forced to ‘0’. However, clearing the CKP bit will not assert the SCL output low until the SCL output is already sampled low. Therefore, the CKP bit will not assert the SCL line until an external I2C master device has already asserted the SCL line. The SCL output will remain low until the CKP bit is set and all other devices on the I2C bus have deasserted SCL. This ensures that a write to the CKP bit will not violate the minimum high time requirement for SCL (see Figure 17-12). FIGURE 17-12: CLOCK SYNCHRONIZATION TIMING SDA SCL DX DX – 1 WR Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 SSPCONx CKP Master device deasserts clock Master device asserts clockPIC18F2420/2520/4420/4520 DS39631E-page 182 © 2008 Microchip Technology Inc. FIGURE 17-13: I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESSING) SDA SCL SSPIF BF (SSPSTAT<0>) SSPOV (SSPCON1<6>) S 1 2 34 56 7 8 9 1 234 5 67 89 1 23 45 7 89 P A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0 ACK Receiving Data ACK Receiving Data R/W = 0 ACK Receiving Address Cleared in software SSPBUF is read Bus master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. D2 6 (PIR1<3>) CKP (SSPCON1<4>) CKP written to ‘1’ in If BF is cleared prior to the falling edge of the 9th clock, CKP will not be reset to ‘0’ and no clock stretching will occur software Clock is held low until CKP is set to ‘1’ Clock is not held low because buffer full bit is clear prior to falling edge of 9th clock Clock is not held low because ACK = 1 BF is set after falling edge of the 9th clock, CKP is reset to ‘0’ and clock stretching occurs© 2008 Microchip Technology Inc. DS39631E-page 183 PIC18F2420/2520/4420/4520 FIGURE 17-14: I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESSING) SDA SCL SSPIF BF (SSPSTAT<0>) S 1 234 56 7 89 12345 67 89 1 2345 78 9 P 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D1 D0 Receive Data Byte ACK R/W = 0 ACK Receive First Byte of Address Cleared in software D2 6 (PIR1<3>) Cleared in software Receive Second Byte of Address Cleared by hardware when SSPADD is updated with low byte of address after falling edge UA (SSPSTAT<1>) Clock is held low until update of SSPADD has taken place UA is set indicating that the SSPADD needs to be updated UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address after falling edge SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag ACK CKP (SSPCON1<4>) D7 D6 D5 D4 D3 D1 D0 12345 789 Receive Data Byte Bus master terminates transfer D2 6 ACK Cleared in software Cleared in software SSPOV (SSPCON1<6>) CKP written to ‘1’ Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. in software Clock is held low until update of SSPADD has taken place of ninth clock of ninth clock SSPOV is set because SSPBUF is still full. ACK is not sent. Dummy read of SSPBUF to clear BF flag Clock is held low until CKP is set to ‘1’ Clock is not held low because ACK = 1PIC18F2420/2520/4420/4520 DS39631E-page 184 © 2008 Microchip Technology Inc. 17.4.5 GENERAL CALL ADDRESS SUPPORT The addressing procedure for the I2C bus is such that the first byte after the Start condition usually determines which device will be the slave addressed by the master. The exception is the general call address which can address all devices. When this address is used, all devices should, in theory, respond with an Acknowledge. The general call address is one of eight addresses reserved for specific purposes by the I2C protocol. It consists of all ‘0’s with R/W = 0. The general call address is recognized when the General Call Enable bit, GCEN, is enabled (SSPCON2<7> is set). Following a Start bit detect, 8 bits are shifted into the SSPSR and the address is compared against the SSPADD. It is also compared to the general call address and fixed in hardware. If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag bit is set (eighth bit) and on the falling edge of the ninth bit (ACK bit), the SSPIF interrupt flag bit is set. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF. The value can be used to determine if the address was device specific or a general call address. In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when the GCEN bit is set, while the slave is configured in 10-Bit Addressing mode, then the second half of the address is not necessary, the UA bit will not be set and the slave will begin receiving data after the Acknowledge (Figure 17-15). FIGURE 17-15: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT ADDRESSING MODE) SDA SCL S SSPIF BF (SSPSTAT<0>) SSPOV (SSPCON1<6>) Cleared in software SSPBUF is read R/W = 0 ACK General Call Address Address is compared to General Call Address GCEN (SSPCON2<7>) Receiving Data ACK 1 2 34 56 7891 2 34 56 789 D7 D6 D5 D4 D3 D2 D1 D0 after ACK, set interrupt ‘0’ ‘1’© 2008 Microchip Technology Inc. DS39631E-page 185 PIC18F2420/2520/4420/4520 17.4.6 MASTER MODE Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware. Master mode of operation is supported by interrupt generation on the detection of the Start and Stop conditions. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I2C bus may be taken when the P bit is set, or the bus is Idle, with both the S and P bits clear. In Firmware Controlled Master mode, user code conducts all I2C bus operations based on Start and Stop bit conditions. Once Master mode is enabled, the user has six options. 1. Assert a Start condition on SDA and SCL. 2. Assert a Repeated Start condition on SDA and SCL. 3. Write to the SSPBUF register initiating transmission of data/address. 4. Configure the I2C port to receive data. 5. Generate an Acknowledge condition at the end of a received byte of data. 6. Generate a Stop condition on SDA and SCL. The following events will cause the MSSP Interrupt Flag bit, SSPIF, to be set (MSSP interrupt, if enabled): • Start condition • Stop condition • Data transfer byte transmitted/received • Acknowledge transmit • Repeated Start FIGURE 17-16: MSSP BLOCK DIAGRAM (I2C™ MASTER MODE) Note: The MSSP module, when configured in I 2C Master mode, does not allow queueing of events. For instance, the user is not allowed to initiate a Start condition and immediately write the SSPBUF register to initiate transmission before the Start condition is complete. In this case, the SSPBUF will not be written to and the WCOL bit will be set, indicating that a write to the SSPBUF did not occur. Read Write SSPSR Start bit, Stop bit, SSPBUF Internal Data Bus Set/Reset, S, P, WCOL (SSPSTAT); Shift Clock MSb LSb SDA Acknowledge Generate Stop bit Detect Write Collision Detect Clock Arbitration State Counter for end of XMIT/RCV SCL SCL In Bus Collision SDA In Receive Enable Clock Cntl Clock Arbitrate/WCOL Detect (hold off clock source) SSPADD<6:0> Baud Set SSPIF, BCLIF; Reset ACKSTAT, PEN (SSPCON2) Rate Generator SSPM<3:0> Start bit DetectPIC18F2420/2520/4420/4520 DS39631E-page 186 © 2008 Microchip Technology Inc. 17.4.6.1 I2C Master Mode Operation The master device generates all of the serial clock pulses and the Start and Stop conditions. A transfer is ended with a Stop condition or with a Repeated Start condition. Since the Repeated Start condition is also the beginning of the next serial transfer, the I2C bus will not be released. In Master Transmitter mode, serial data is output through SDA, while SCL outputs the serial clock. The first byte transmitted contains the slave address of the receiving device (7 bits) and the Read/Write (R/W) bit. In this case, the R/W bit will be logic ‘0’. Serial data is transmitted 8 bits at a time. After each byte is transmitted, an Acknowledge bit is received. Start and Stop conditions are output to indicate the beginning and the end of a serial transfer. In Master Receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the R/W bit. In this case, the R/W bit will be logic ‘1’. Thus, the first byte transmitted is a 7-bit slave address followed by a ‘1’ to indicate the receive bit. Serial data is received via SDA, while SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an Acknowledge bit is transmitted. Start and Stop conditions indicate the beginning and end of transmission. The Baud Rate Generator used for the SPI mode operation is used to set the SCL clock frequency for either 100 kHz, 400 kHz or 1 MHz I2C operation. See Section 17.4.7 “Baud Rate” for more detail. A typical transmit sequence would go as follows: 1. The user generates a Start condition by setting the Start Enable bit, SEN (SSPCON2<0>). 2. SSPIF is set. The MSSP module will wait the required start time before any other operation takes place. 3. The user loads the SSPBUF with the slave address to transmit. 4. Address is shifted out the SDA pin until all 8 bits are transmitted. 5. The MSSP module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 6. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 7. The user loads the SSPBUF with eight bits of data. 8. Data is shifted out the SDA pin until all 8 bits are transmitted. 9. The MSSP module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 10. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 11. The user generates a Stop condition by setting the Stop Enable bit, PEN (SSPCON2<2>). 12. Interrupt is generated once the Stop condition is complete.© 2008 Microchip Technology Inc. DS39631E-page 187 PIC18F2420/2520/4420/4520 17.4.7 BAUD RATE In I2C Master mode, the Baud Rate Generator (BRG) reload value is placed in the lower 7 bits of the SSPADD register (Figure 17-17). When a write occurs to SSPBUF, the Baud Rate Generator will automatically begin counting. The BRG counts down to 0 and stops until another reload has taken place. The BRG count is decremented twice per instruction cycle (TCY) on the Q2 and Q4 clocks. In I2C Master mode, the BRG is reloaded automatically. Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal clock will automatically stop counting and the SCL pin will remain in its last state. Table 17-3 demonstrates clock rates based on instruction cycles and the BRG value loaded into SSPADD. FIGURE 17-17: BAUD RATE GENERATOR BLOCK DIAGRAM TABLE 17-3: I2C™ CLOCK RATE W/BRG SSPM<3:0> CLKO BRG Down Counter FOSC/4 SSPADD<6:0> SSPM<3:0> SCL Reload Control Reload FCY FCY * 2 BRG Value FSCL (2 Rollovers of BRG) 10 MHz 20 MHz 18h 400 kHz(1) 10 MHz 20 MHz 1Fh 312.5 kHz 10 MHz 20 MHz 63h 100 kHz 4 MHz 8 MHz 09h 400 kHz(1) 4 MHz 8 MHz 0Ch 308 kHz 4 MHz 8 MHz 27h 100 kHz 1 MHz 2 MHz 02h 333 kHz(1) 1 MHz 2 MHz 09h 100 kHz 1 MHz 2 MHz 00h 1 MHz(1) Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than 100 kHz) in all details, but may be used with care where higher rates are required by the application.PIC18F2420/2520/4420/4520 DS39631E-page 188 © 2008 Microchip Technology Inc. 17.4.7.1 Clock Arbitration Clock arbitration occurs when the master, during any receive, transmit or Repeated Start/Stop condition, deasserts the SCL pin (SCL allowed to float high). When the SCL pin is allowed to float high, the Baud Rate Generator (BRG) is suspended from counting until the SCL pin is actually sampled high. When the SCL pin is sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and begins counting. This ensures that the SCL high time will always be at least one BRG rollover count in the event that the clock is held low by an external device (Figure 17-18). FIGURE 17-18: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION SDA SCL SCL deasserted but slave holds DX DX – 1 BRG SCL is sampled high, reload takes place and BRG starts its count 03h 02h 01h 00h (hold off) 03h 02h Reload BRG Value SCL low (clock arbitration) SCL allowed to transition high BRG decrements on Q2 and Q4 cycles© 2008 Microchip Technology Inc. DS39631E-page 189 PIC18F2420/2520/4420/4520 17.4.8 I2C MASTER MODE START CONDITION TIMING To initiate a Start condition, the user sets the Start Enable bit, SEN (SSPCON2<0>). If the SDA and SCL pins are sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and starts its count. If SCL and SDA are both sampled high when the Baud Rate Generator times out (TBRG), the SDA pin is driven low. The action of the SDA being driven low while SCL is high is the Start condition and causes the S bit (SSPSTAT<3>) to be set. Following this, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and resumes its count. When the Baud Rate Generator times out (TBRG), the SEN bit (SSPCON2<0>) will be automatically cleared by hardware; the Baud Rate Generator is suspended, leaving the SDA line held low and the Start condition is complete. 17.4.8.1 WCOL Status Flag If the user writes the SSPBUF when a Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 17-19: FIRST START BIT TIMING Note: If, at the beginning of the Start condition, the SDA and SCL pins are already sampled low, or if during the Start condition, the SCL line is sampled low before the SDA line is driven low, a bus collision occurs, the Bus Collision Interrupt Flag, BCLIF, is set, the Start condition is aborted and the I 2C module is reset into its Idle state. Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the Start condition is complete. SDA SCL S TBRG 1st bit 2nd bit TBRG SDA = 1, At completion of Start bit, SCL = 1 TBRG Write to SSPBUF occurs here hardware clears SEN bit TBRG Write to SEN bit occurs here Set S bit (SSPSTAT<3>) and sets SSPIF bitPIC18F2420/2520/4420/4520 DS39631E-page 190 © 2008 Microchip Technology Inc. 17.4.9 I2C MASTER MODE REPEATED START CONDITION TIMING A Repeated Start condition occurs when the RSEN bit (SSPCON2<1>) is programmed high and the I2C logic module is in the Idle state. When the RSEN bit is set, the SCL pin is asserted low. When the SCL pin is sampled low, the Baud Rate Generator is loaded with the contents of SSPADD<5:0> and begins counting. The SDA pin is released (brought high) for one Baud Rate Generator count (TBRG). When the Baud Rate Generator times out, if SDA is sampled high, the SCL pin will be deasserted (brought high). When SCL is sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and SCL must be sampled high for one TBRG. This action is then followed by assertion of the SDA pin (SDA = 0) for one TBRG while SCL is high. Following this, the RSEN bit (SSPCON2<1>) will be automatically cleared and the Baud Rate Generator will not be reloaded, leaving the SDA pin held low. As soon as a Start condition is detected on the SDA and SCL pins, the S bit (SSPSTAT<3>) will be set. The SSPIF bit will not be set until the Baud Rate Generator has timed out. Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7-bit mode or the default first address in 10-bit mode. After the first eight bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode) or eight bits of data (7-bit mode). 17.4.9.1 WCOL Status Flag If the user writes the SSPBUF when a Repeated Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 17-20: REPEATED START CONDITION WAVEFORM Note 1: If RSEN is programmed while any other event is in progress, it will not take effect. 2: A bus collision during the Repeated Start condition occurs if: • SDA is sampled low when SCL goes from low-to-high. • SCL goes low before SDA is asserted low. This may indicate that another master is attempting to transmit a data ‘1’. Note: Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated Start condition is complete. SDA SCL Sr = Repeated Start Write to SSPCON2 Write to SSPBUF occurs here on falling edge of ninth clock, end of Xmit At completion of Start bit, hardware clears RSEN bit 1st bit S bit set by hardware TBRG TBRG SDA = 1, SDA = 1, SCL (no change). SCL = 1 occurs here. TBRG TBRG TBRG and sets SSPIF RSEN bit set by hardware© 2008 Microchip Technology Inc. DS39631E-page 191 PIC18F2420/2520/4420/4520 17.4.10 I2C MASTER MODE TRANSMISSION Transmission of a data byte, a 7-bit address or the other half of a 10-bit address is accomplished by simply writing a value to the SSPBUF register. This action will set the Buffer Full flag bit, BF, and allow the Baud Rate Generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto the SDA pin after the falling edge of SCL is asserted (see data hold time specification parameter 106). SCL is held low for one Baud Rate Generator rollover count (TBRG). Data should be valid before SCL is released high (see data setup time specification parameter 107). When the SCL pin is released high, it is held that way for TBRG. The data on the SDA pin must remain stable for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the falling edge of the eighth clock), the BF flag is cleared and the master releases SDA. This allows the slave device being addressed to respond with an ACK bit during the ninth bit time if an address match occurred, or if data was received properly. The status of ACK is written into the ACKDT bit on the falling edge of the ninth clock. If the master receives an Acknowledge, the Acknowledge Status bit, ACKSTAT, is cleared. If not, the bit is set. After the ninth clock, the SSPIF bit is set and the master clock (Baud Rate Generator) is suspended until the next data byte is loaded into the SSPBUF, leaving SCL low and SDA unchanged (Figure 17-21). After the write to the SSPBUF, each bit of the address will be shifted out on the falling edge of SCL until all seven address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will deassert the SDA pin, allowing the slave to respond with an Acknowledge. On the falling edge of the ninth clock, the master will sample the SDA pin to see if the address was recognized by a slave. The status of the ACK bit is loaded into the ACKSTAT status bit (SSPCON2<6>). Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is cleared and the Baud Rate Generator is turned off until another write to the SSPBUF takes place, holding SCL low and allowing SDA to float. 17.4.10.1 BF Status Flag In Transmit mode, the BF bit (SSPSTAT<0>) is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out. 17.4.10.2 WCOL Status Flag If the user writes the SSPBUF when a transmit is already in progress (i.e., SSPSR is still shifting out a data byte), the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). WCOL must be cleared in software. 17.4.10.3 ACKSTAT Status Flag In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is cleared when the slave has sent an Acknowledge (ACK = 0) and is set when the slave does not Acknowledge (ACK = 1). A slave sends an Acknowledge when it has recognized its address (including a general call), or when the slave has properly received its data. 17.4.11 I2C MASTER MODE RECEPTION Master mode reception is enabled by programming the Receive Enable bit, RCEN (SSPCON2<3>). The Baud Rate Generator begins counting and on each rollover, the state of the SCL pin changes (high-to-low/ low-to-high) and data is shifted into the SSPSR. After the falling edge of the eighth clock, the receive enable flag is automatically cleared, the contents of the SSPSR are loaded into the SSPBUF, the BF flag bit is set, the SSPIF flag bit is set and the Baud Rate Generator is suspended from counting, holding SCL low. The MSSP is now in Idle state awaiting the next command. When the buffer is read by the CPU, the BF flag bit is automatically cleared. The user can then send an Acknowledge bit at the end of reception by setting the Acknowledge Sequence Enable bit, ACKEN (SSPCON2<4>). 17.4.11.1 BF Status Flag In receive operation, the BF bit is set when an address or data byte is loaded into SSPBUF from SSPSR. It is cleared when the SSPBUF register is read. 17.4.11.2 SSPOV Status Flag In receive operation, the SSPOV bit is set when 8 bits are received into the SSPSR and the BF flag bit is already set from a previous reception. 17.4.11.3 WCOL Status Flag If the user writes the SSPBUF when a receive is already in progress (i.e., SSPSR is still shifting in a data byte), the WCOL bit is set and the contents of the buffer are unchanged (the write doesn’t occur). Note: The MSSP module must be in an Idle state before the RCEN bit is set or the RCEN bit will be disregarded. PIC18F2420/2520/4420/4520 DS39631E-page 192 © 2008 Microchip Technology Inc. FIGURE 17-21: I2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESSING) SDA SCL SSPIF BF (SSPSTAT<0>) SEN A7 A6 A5 A4 A3 A2 A1 ACK = ‘0’ D7 D6 D5 D4 D3 D2 D1 D0 ACK Transmitting Data or Second Half R/W = 0 Transmit Address to Slave 123456789 123456789 P Cleared in software service routine from MSSP interrupt SSPBUF is written in software After Start condition, SEN cleared by hardware S SSPBUF written with 7-bit address and R/W start transmit SCL held low while CPU responds to SSPIF SEN = 0 of 10-Bit Address Write SSPCON2<0> SEN = 1 Start condition begins From slave, clear ACKSTAT bit SSPCON2<6> ACKSTAT in SSPCON2 = 1 Cleared in software SSPBUF written PEN R/W Cleared in software© 2008 Microchip Technology Inc. DS39631E-page 193 PIC18F2420/2520/4420/4520 FIGURE 17-22: I2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESSING) P 9 8 7 6 5 D0 D1 D2 D3 D4 D5 D6 D7 S A7 A6 A5 A4 A3 A2 A1 SDA SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 678 9 1234 Bus master terminates transfer ACK Receiving Data from Slave Receiving Data from Slave D0 D1 D2 D3 D4 D5 D6 D7 ACK R/W = 0 Transmit Address to Slave SSPIF BF ACK is not sent Write to SSPCON2<0> (SEN = 1), Write to SSPBUF occurs here, ACK from Slave Master configured as a receiver by programming SSPCON2<3> (RCEN = 1) PEN bit = 1 written here Data shifted in on falling edge of CLK Cleared in software start XMIT SEN = 0 SSPOV SDA = 0, SCL = 1 while CPU (SSPSTAT<0>) ACK Cleared in software Cleared in software Set SSPIF interrupt at end of receive Set P bit (SSPSTAT<4>) and SSPIF Cleared in software ACK from Master Set SSPIF at end Set SSPIF interrupt at end of Acknowledge sequence Set SSPIF interrupt at end of Acknowledge sequence of receive Set ACKEN, start Acknowledge sequence SSPOV is set because SSPBUF is still full SDA = ACKDT = 1 RCEN cleared automatically RCEN = 1, start next receive Write to SSPCON2<4> to start Acknowledge sequence SDA = ACKDT (SSPCON2<5>) = 0 RCEN cleared automatically responds to SSPIF ACKEN begin Start condition Cleared in software SDA = ACKDT = 0 Last bit is shifted into SSPSR and contents are unloaded into SSPBUFPIC18F2420/2520/4420/4520 DS39631E-page 194 © 2008 Microchip Technology Inc. 17.4.12 ACKNOWLEDGE SEQUENCE TIMING An Acknowledge sequence is enabled by setting the Acknowledge Sequence Enable bit, ACKEN (SSPCON2<4>). When this bit is set, the SCL pin is pulled low and the contents of the Acknowledge data bit are presented on the SDA pin. If the user wishes to generate an Acknowledge, then the ACKDT bit should be cleared. If not, the user should set the ACKDT bit before starting an Acknowledge sequence. The Baud Rate Generator then counts for one rollover period (TBRG) and the SCL pin is deasserted (pulled high). When the SCL pin is sampled high (clock arbitration), the Baud Rate Generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the Baud Rate Generator is turned off and the MSSP module then goes into Idle mode (Figure 17-23). 17.4.12.1 WCOL Status Flag If the user writes the SSPBUF when an Acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). 17.4.13 STOP CONDITION TIMING A Stop bit is asserted on the SDA pin at the end of a receive/transmit by setting the Stop Sequence Enable bit, PEN (SSPCON2<2>). At the end of a receive/ transmit, the SCL line is held low after the falling edge of the ninth clock. When the PEN bit is set, the master will assert the SDA line low. When the SDA line is sampled low, the Baud Rate Generator is reloaded and counts down to 0. When the Baud Rate Generator times out, the SCL pin will be brought high and one TBRG (Baud Rate Generator rollover count) later, the SDA pin will be deasserted. When the SDA pin is sampled high while SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 17-24). 17.4.13.1 WCOL Status Flag If the user writes the SSPBUF when a Stop sequence is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 17-23: ACKNOWLEDGE SEQUENCE WAVEFORM FIGURE 17-24: STOP CONDITION RECEIVE OR TRANSMIT MODE Note: TBRG = one Baud Rate Generator period. SDA SCL SSPIF set at Acknowledge sequence starts here, write to SSPCON2 ACKEN automatically cleared Cleared in TBRG TBRG the end of receive 8 ACKEN = 1, ACKDT = 0 D0 9 SSPIF software SSPIF set at the end of Acknowledge sequence Cleared in software ACK SCL SDA SDA asserted low before rising edge of clock Write to SSPCON2, set PEN Falling edge of SCL = 1 for TBRG, followed by SDA = 1 for TBRG 9th clock SCL brought high after TBRG Note: TBRG = one Baud Rate Generator period. TBRG TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. TBRG to setup Stop condition ACK P TBRG PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set© 2008 Microchip Technology Inc. DS39631E-page 195 PIC18F2420/2520/4420/4520 17.4.14 SLEEP OPERATION While in Sleep mode, the I2C module can receive addresses or data and when an address match or complete byte transfer occurs, wake the processor from Sleep (if the MSSP interrupt is enabled). 17.4.15 EFFECTS OF A RESET A Reset disables the MSSP module and terminates the current transfer. 17.4.16 MULTI-MASTER MODE In Multi-Master mode, the interrupt generation on the detection of the Start and Stop conditions allows the determination of when the bus is free. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I2C bus may be taken when the P bit (SSPSTAT<4>) is set, or the bus is Idle, with both the S and P bits clear. When the bus is busy, enabling the MSSP interrupt will generate the interrupt when the Stop condition occurs. In multi-master operation, the SDA line must be monitored for arbitration to see if the signal level is the expected output level. This check is performed in hardware with the result placed in the BCLIF bit. The states where arbitration can be lost are: • Address Transfer • Data Transfer • A Start Condition • A Repeated Start Condition • An Acknowledge Condition 17.4.17 MULTI -MASTER COMMUNICATION, BUS COLLISION AND BUS ARBITRATION Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto the SDA pin, arbitration takes place when the master outputs a ‘1’ on SDA by letting SDA float high and another master asserts a ‘0’. When the SCL pin floats high, data should be stable. If the expected data on SDA is a ‘1’ and the data sampled on the SDA pin = 0, then a bus collision has taken place. The master will set the Bus Collision Interrupt Flag, BCLIF and reset the I 2C port to its Idle state (Figure 17-25). If a transmit was in progress when the bus collision occurred, the transmission is halted, the BF flag is cleared, the SDA and SCL lines are deasserted and the SSPBUF can be written to. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a Start condition. If a Start, Repeated Start, Stop or Acknowledge condition was in progress when the bus collision occurred, the condition is aborted, the SDA and SCL lines are deasserted and the respective control bits in the SSPCON2 register are cleared. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a Start condition. The master will continue to monitor the SDA and SCL pins. If a Stop condition occurs, the SSPIF bit will be set. A write to the SSPBUF will start the transmission of data at the first data bit, regardless of where the transmitter left off when the bus collision occurred. In Multi-Master mode, the interrupt generation on the detection of Start and Stop conditions allows the determination of when the bus is free. Control of the I2C bus can be taken when the P bit is set in the SSPSTAT register, or the bus is Idle and the S and P bits are cleared. FIGURE 17-25: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE SDA SCL BCLIF SDA released SDA line pulled low by another source Sample SDA. While SCL is high, data doesn’t match what is driven Bus collision has occurred. Set bus collision interrupt (BCLIF) by the master. by master Data changes while SCL = 0PIC18F2420/2520/4420/4520 DS39631E-page 196 © 2008 Microchip Technology Inc. 17.4.17.1 Bus Collision During a Start Condition During a Start condition, a bus collision occurs if: a) SDA or SCL is sampled low at the beginning of the Start condition (Figure 17-26). b) SCL is sampled low before SDA is asserted low (Figure 17-27). During a Start condition, both the SDA and the SCL pins are monitored. If the SDA pin is already low, or the SCL pin is already low, then all of the following occur: • the Start condition is aborted, • the BCLIF flag is set and • the MSSP module is reset to its Idle state (Figure 17-26). The Start condition begins with the SDA and SCL pins deasserted. When the SDA pin is sampled high, the Baud Rate Generator is loaded from SSPADD<6:0> and counts down to 0. If the SCL pin is sampled low while SDA is high, a bus collision occurs because it is assumed that another master is attempting to drive a data ‘1’ during the Start condition. If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 17-28). If, however, a ‘1’ is sampled on the SDA pin, the SDA pin is asserted low at the end of the BRG count. The Baud Rate Generator is then reloaded and counts down to 0; if the SCL pin is sampled as ‘0’ during this time, a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. FIGURE 17-26: BUS COLLISION DURING START CONDITION (SDA ONLY) Note: The reason that bus collision is not a factor during a Start condition is that no two bus masters can assert a Start condition at the exact same time. Therefore, one master will always assert SDA before the other. This condition does not cause a bus collision because the two masters must be allowed to arbitrate the first address following the Start condition. If the address is the same, arbitration must be allowed to continue into the data portion, Repeated Start or Stop conditions. SDA SCL SEN SDA sampled low before SDA goes low before the SEN bit is set. S bit and SSPIF set because MSSP module reset into Idle state. SEN cleared automatically because of bus collision. S bit and SSPIF set because Set SEN, enable Start condition if SDA = 1, SCL = 1 SDA = 0, SCL = 1. BCLIF S SSPIF SDA = 0, SCL = 1. SSPIF and BCLIF are cleared in software SSPIF and BCLIF are cleared in software Set BCLIF, Start condition. Set BCLIF.© 2008 Microchip Technology Inc. DS39631E-page 197 PIC18F2420/2520/4420/4520 FIGURE 17-27: BUS COLLISION DURING START CONDITION (SCL = 0) FIGURE 17-28: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION SDA SCL SEN bus collision occurs. Set BCLIF. SCL = 0 before SDA = 0, Set SEN, enable Start sequence if SDA = 1, SCL = 1 TBRG TBRG SDA = 0, SCL = 1 BCLIF S SSPIF Interrupt cleared in software bus collision occurs. Set BCLIF. SCL = 0 before BRG time-out, ‘0’ ‘0’ ‘0’ ‘0’ SDA SCL SEN Set S Less than TBRG TBRG SDA = 0, SCL = 1 BCLIF S SSPIF S Interrupts cleared set SSPIF in software SDA = 0, SCL = 1, SCL pulled low after BRG time-out Set SSPIF ‘0’ SDA pulled low by other master. Reset BRG and assert SDA. Set SEN, enable Start sequence if SDA = 1, SCL = 1PIC18F2420/2520/4420/4520 DS39631E-page 198 © 2008 Microchip Technology Inc. 17.4.17.2 Bus Collision During a Repeated Start Condition During a Repeated Start condition, a bus collision occurs if: a) A low level is sampled on SDA when SCL goes from low level to high level. b) SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data ‘1’. When the user deasserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD<6:0> and counts down to 0. The SCL pin is then deasserted and when sampled high, the SDA pin is sampled. If SDA is low, a bus collision has occurred (i.e., another master is attempting to transmit a data ‘0’, Figure 17-29). If SDA is sampled high, the BRG is reloaded and begins counting. If SDA goes from high-to-low before the BRG times out, no bus collision occurs because no two masters can assert SDA at exactly the same time. If SCL goes from high-to-low before the BRG times out and SDA has not already been asserted, a bus collision occurs. In this case, another master is attempting to transmit a data ‘1’ during the Repeated Start condition, see Figure 17-30. If, at the end of the BRG time-out, both SCL and SDA are still high, the SDA pin is driven low and the BRG is reloaded and begins counting. At the end of the count, regardless of the status of the SCL pin, the SCL pin is driven low and the Repeated Start condition is complete. FIGURE 17-29: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1) FIGURE 17-30: BUS COLLISION DURING REPEATED START CONDITION (CASE 2) SDA SCL RSEN BCLIF S SSPIF Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. Cleared in software ‘0’ ‘0’ SDA SCL BCLIF RSEN S SSPIF Interrupt cleared in software SCL goes low before SDA, set BCLIF. Release SDA and SCL. TBRG TBRG ‘0’© 2008 Microchip Technology Inc. DS39631E-page 199 PIC18F2420/2520/4420/4520 17.4.17.3 Bus Collision During a Stop Condition Bus collision occurs during a Stop condition if: a) After the SDA pin has been deasserted and allowed to float high, SDA is sampled low after the BRG has timed out. b) After the SCL pin is deasserted, SCL is sampled low before SDA goes high. The Stop condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allowed to float. When the pin is sampled high (clock arbitration), the Baud Rate Generator is loaded with SSPADD<6:0> and counts down to 0. After the BRG times out, SDA is sampled. If SDA is sampled low, a bus collision has occurred. This is due to another master attempting to drive a data ‘0’ (Figure 17-31). If the SCL pin is sampled low before SDA is allowed to float high, a bus collision occurs. This is another case of another master attempting to drive a data ‘0’ (Figure 17-32). FIGURE 17-31: BUS COLLISION DURING A STOP CONDITION (CASE 1) FIGURE 17-32: BUS COLLISION DURING A STOP CONDITION (CASE 2) SDA SCL BCLIF PEN P SSPIF TBRG TBRG TBRG SDA asserted low SDA sampled low after TBRG, set BCLIF ‘0’ ‘0’ SDA SCL BCLIF PEN P SSPIF TBRG TBRG TBRG Assert SDA SCL goes low before SDA goes high, set BCLIF ‘0’ ‘0’PIC18F2420/2520/4420/4520 DS39631E-page 200 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 201 PIC18F2420/2520/4420/4520 18.0 ENHANCED UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (EUSART) The Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module is one of the two serial I/O modules. (Generically, the USART is also known as a Serial Communications Interface or SCI.) The EUSART can be configured as a full-duplex asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers. It can also be configured as a halfduplex, synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. The Enhanced USART module implements additional features, including automatic baud rate detection and calibration, automatic wake-up on Sync Break reception and 12-bit Break character transmit. These make it ideally suited for use in Local Interconnect Network bus (LIN bus) systems. The EUSART can be configured in the following modes: • Asynchronous (full duplex) with: - Auto-wake-up on character reception - Auto-baud calibration - 12-bit Break character transmission • Synchronous – Master (half duplex) with selectable clock polarity • Synchronous – Slave (half duplex) with selectable clock polarity The pins of the Enhanced USART are multiplexed with PORTC. In order to configure RC6/TX/CK and RC7/RX/DT as an EUSART: • bit SPEN (RCSTA<7>) must be set (= 1) • bit TRISC<7> must be set (= 1) • bit TRISC<6> must be set (= 1) The operation of the Enhanced USART module is controlled through three registers: • Transmit Status and Control (TXSTA) • Receive Status and Control (RCSTA) • Baud Rate Control (BAUDCON) These are detailed on the following pages in Register 18-1, Register 18-2 and Register 18-3, respectively. Note: The EUSART control will automatically reconfigure the pin from input to output as needed.PIC18F2420/2520/4420/4520 DS39631E-page 202 © 2008 Microchip Technology Inc. REGISTER 18-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN(1) SYNC SENDB BRGH TRMT TX9D bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 CSRC: Clock Source Select bit Asynchronous mode: Don’t care. Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) bit 6 TX9: 9-Bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission bit 5 TXEN: Transmit Enable bit(1) 1 = Transmit enabled 0 = Transmit disabled bit 4 SYNC: EUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 SENDB: Send Break Character bit Asynchronous mode: 1 = Send Sync Break on next transmission (cleared by hardware upon completion) 0 = Sync Break transmission completed Synchronous mode: Don’t care. bit 2 BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode. bit 1 TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full bit 0 TX9D: 9th Bit of Transmit Data Can be address/data bit or a parity bit. Note 1: SREN/CREN overrides TXEN in Sync mode.© 2008 Microchip Technology Inc. DS39631E-page 203 PIC18F2420/2520/4420/4520 REGISTER 18-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x SPEN RX9 SREN CREN ADDEN FERR OERR RX9D bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins) 0 = Serial port disabled (held in Reset) bit 6 RX9: 9-Bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5 SREN: Single Receive Enable bit Asynchronous mode: Don’t care. Synchronous mode – Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode – Slave: Don’t care. bit 4 CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN) 0 = Disables continuous receive bit 3 ADDEN: Address Detect Enable bit Asynchronous mode 9-Bit (RX9 = 1): 1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit Asynchronous mode 9-Bit (RX9 = 0): Don’t care. bit 2 FERR: Framing Error bit 1 = Framing error (can be cleared by reading RCREG register and receiving next valid byte) 0 = No framing error bit 1 OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit, CREN) 0 = No overrun error bit 0 RX9D: 9th Bit of Received Data This can be address/data bit or a parity bit and must be calculated by user firmware.PIC18F2420/2520/4420/4520 DS39631E-page 204 © 2008 Microchip Technology Inc. REGISTER 18-3: BAUDCON: BAUD RATE CONTROL REGISTER R/W-0 R-1 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 ABDOVF: Auto-Baud Acquisition Rollover Status bit 1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software) 0 = No BRG rollover has occurred bit 6 RCIDL: Receive Operation Idle Status bit 1 = Receive operation is Idle 0 = Receive operation is active bit 5 RXDTP: Data/Receive Polarity Select bit Asynchronous mode: 1 = Receive data (RX) is inverted (active-low) 0 = Receive data (RX) is not inverted (active-high) Synchronous mode: 1 = Data (DT) is inverted (active-low) 0 = Data (DT) is not inverted (active-high) bit 4 TXCKP: Clock and Data Polarity Select bit Asynchronous mode: 1 = Idle state for transmit (TX) is a low level 0 = Idle state for transmit (TX) is a high level Synchronous mode: 1 = Idle state for clock (CK) is a high level 0 = Idle state for clock (CK) is a low level bit 3 BRG16: 16-Bit Baud Rate Register Enable bit 1 = 16-bit Baud Rate Generator – SPBRGH and SPBRG 0 = 8-bit Baud Rate Generator – SPBRG only (Compatible mode), SPBRGH value ignored bit 2 Unimplemented: Read as ‘0’ bit 1 WUE: Wake-up Enable bit Asynchronous mode: 1 = EUSART will continue to sample the RX pin – interrupt generated on falling edge; bit cleared in hardware on following rising edge 0 = RX pin not monitored or rising edge detected Synchronous mode: Unused in this mode. bit 0 ABDEN: Auto-Baud Detect Enable bit Asynchronous mode: 1 = Enable baud rate measurement on the next character. Requires reception of a Sync field (55h); cleared in hardware upon completion. 0 = Baud rate measurement disabled or completed Synchronous mode: Unused in this mode.© 2008 Microchip Technology Inc. DS39631E-page 205 PIC18F2420/2520/4420/4520 18.1 Baud Rate Generator (BRG) The BRG is a dedicated, 8-bit or 16-bit generator that supports both the Asynchronous and Synchronous modes of the EUSART. By default, the BRG operates in 8-bit mode; setting the BRG16 bit (BAUDCON<3>) selects 16-bit mode. The SPBRGH:SPBRG register pair controls the period of a free-running timer. In Asynchronous mode, bits, BRGH (TXSTA<2>) and BRG16 (BAUDCON<3>), also control the baud rate. In Synchronous mode, BRGH is ignored. Table 18-1 shows the formula for computation of the baud rate for different EUSART modes which only apply in Master mode (internally generated clock). Given the desired baud rate and FOSC, the nearest integer value for the SPBRGH:SPBRG registers can be calculated using the formulas in Table 18-1. From this, the error in baud rate can be determined. An example calculation is shown in Example 18-1. Typical baud rates and error values for the various Asynchronous modes are shown in Table 18-2. It may be advantageous to use the high baud rate (BRGH = 1) or the 16-bit BRG to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. Writing a new value to the SPBRGH:SPBRG registers causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate. 18.1.1 OPERATION IN POWER-MANAGED MODES The device clock is used to generate the desired baud rate. When one of the power-managed modes is entered, the new clock source may be operating at a different frequency. This may require an adjustment to the value in the SPBRG register pair. 18.1.2 SAMPLING The data on the RX pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX pin. TABLE 18-1: BAUD RATE FORMULAS Configuration Bits BRG/EUSART Mode Baud Rate Formula SYNC BRG16 BRGH 000 8-Bit/Asynchronous FOSC/[64 (n + 1)] 001 8-Bit/Asynchronous FOSC/[16 (n + 1)] 010 16-Bit/Asynchronous 011 16-Bit/Asynchronous 10x 8-Bit/Synchronous FOSC/[4 (n + 1)] 11x 16-Bit/Synchronous Legend: x = Don’t care, n = value of SPBRGH:SPBRG register pairPIC18F2420/2520/4420/4520 DS39631E-page 206 © 2008 Microchip Technology Inc. EXAMPLE 18-1: CALCULATING BAUD RATE ERROR TABLE 18-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG. For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG: Desired Baud Rate = FOSC/(64 ([SPBRGH:SPBRG] + 1)) Solving for SPBRGH:SPBRG: X = ((FOSC/Desired Baud Rate)/64) – 1 = ((16000000/9600)/64) – 1 = [25.042] = 25 Calculated Baud Rate = 16000000/(64 (25 + 1)) = 9615 Error = (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate = (9615 – 9600)/9600 = 0.16% © 2008 Microchip Technology Inc. DS39631E-page 207 PIC18F2420/2520/4420/4520 TABLE 18-3: BAUD RATES FOR ASYNCHRONOUS MODES BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 0 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 — — — — — — — — — — — — 1.2 — — — 1.221 1.73 255 1.202 0.16 129 1.201 -0.16 103 2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2.403 -0.16 51 9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9.615 -0.16 12 19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7 — — — 57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2 — — — 115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1 — — — BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 0 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 0.300 0.16 207 0.300 -0.16 103 0.300 -0.16 51 1.2 1.202 0.16 51 1.201 -0.16 25 1.201 -0.16 12 2.4 2.404 0.16 25 2.403 -0.16 12 — — — 9.6 8.929 -6.99 6 — — — — — — 19.2 20.833 8.51 2 — — — — — — 57.6 62.500 8.51 0 — — — — — — 115.2 62.500 -45.75 0 — — — — — — BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 0 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 — — — — — — — — — — — — 1.2 — — — — — — — — — — — — 2.4 — — — — — — 2.441 1.73 255 2.403 -0.16 207 9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 — — — BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 0 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 — — — — — — 0.300 -0.16 207 1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51 2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25 9.6 9.615 0.16 25 9.615 -0.16 12 — — — 19.2 19.231 0.16 12 — — — — — — 57.6 62.500 8.51 3 — — — — — — 115.2 125.000 8.51 1 — — — — — —PIC18F2420/2520/4420/4520 DS39631E-page 208 © 2008 Microchip Technology Inc. BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 1 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 0.300 -0.04 1665 1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1.201 -0.16 415 2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2.403 -0.16 207 9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 — — — BAUD RATE (K) SYNC = 0, BRGH = 0, BRG16 = 1 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 0.300 0.04 832 0.300 -0.16 415 0.300 -0.16 207 1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51 2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25 9.6 9.615 0.16 25 9.615 -0.16 12 — — — 19.2 19.231 0.16 12 — — — — — — 57.6 62.500 8.51 3 — — — — — — 115.2 125.000 8.51 1 — — — — — — BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 0.300 0.00 33332 0.300 0.00 16665 0.300 0.00 8332 0.300 -0.01 6665 1.2 1.200 0.00 8332 1.200 0.02 4165 1.200 0.02 2082 1.200 -0.04 1665 2.4 2.400 0.02 4165 2.400 0.02 2082 2.402 0.06 1040 2.400 -0.04 832 9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9.615 -0.16 207 19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19.230 -0.16 103 57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57.142 0.79 34 115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117.647 -2.12 16 BAUD RATE (K) SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) Actual Rate (K) % Error SPBRG Value (decimal) 0.3 0.300 0.01 3332 0.300 -0.04 1665 0.300 -0.04 832 1.2 1.200 0.04 832 1.201 -0.16 415 1.201 -0.16 207 2.4 2.404 0.16 415 2.403 -0.16 207 2.403 -0.16 103 9.6 9.615 0.16 103 9.615 -0.16 51 9.615 -0.16 25 19.2 19.231 0.16 51 19.230 -0.16 25 19.230 -0.16 12 57.6 58.824 2.12 16 55.555 3.55 8 — — — 115.2 111.111 -3.55 8 — — — — — — TABLE 18-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)© 2008 Microchip Technology Inc. DS39631E-page 209 PIC18F2420/2520/4420/4520 18.1.3 AUTO-BAUD RATE DETECT The Enhanced USART module supports the automatic detection and calibration of baud rate. This feature is active only in Asynchronous mode and while the WUE bit is clear. The automatic baud rate measurement sequence (Figure 18-1) begins whenever a Start bit is received and the ABDEN bit is set. The calculation is self-averaging. In the Auto-Baud Rate Detect (ABD) mode, the clock to the BRG is reversed. Rather than the BRG clocking the incoming RX signal, the RX signal is timing the BRG. In ABD mode, the internal Baud Rate Generator is used as a counter to time the bit period of the incoming serial byte stream. Once the ABDEN bit is set, the state machine will clear the BRG and look for a Start bit. The Auto-Baud Rate Detect must receive a byte with the value 55h (ASCII “U”, which is also the LIN bus Sync character) in order to calculate the proper bit rate. The measurement is taken over both a low and a high bit time in order to minimize any effects caused by asymmetry of the incoming signal. After a Start bit, the SPBRG begins counting up, using the preselected clock source on the first rising edge of RX. After eight bits on the RX pin or the fifth rising edge, an accumulated value totalling the proper BRG period is left in the SPBRGH:SPBRG register pair. Once the 5th edge is seen (this should correspond to the Stop bit), the ABDEN bit is automatically cleared. If a rollover of the BRG occurs (an overflow from FFFFh to 0000h), the event is trapped by the ABDOVF status bit (BAUDCON<7>). It is set in hardware by BRG rollovers and can be set or cleared by the user in software. ABD mode remains active after rollover events and the ABDEN bit remains set (Figure 18-2). While calibrating the baud rate period, the BRG registers are clocked at 1/8th the preconfigured clock rate. Note that the BRG clock will be configured by the BRG16 and BRGH bits. Independent of the BRG16 bit setting, both the SPBRG and SPBRGH will be used as a 16-bit counter. This allows the user to verify that no carry occurred for 8-bit modes by checking for 00h in the SPBRGH register. Refer to Table 18-4 for counter clock rates to the BRG. While the ABD sequence takes place, the EUSART state machine is held in Idle. The RCIF interrupt is set once the fifth rising edge on RX is detected. The value in the RCREG needs to be read to clear the RCIF interrupt. The contents of RCREG should be discarded. TABLE 18-4: BRG COUNTER CLOCK RATES 18.1.3.1 ABD and EUSART Transmission Since the BRG clock is reversed during ABD acquisition, the EUSART transmitter cannot be used during ABD. This means that whenever the ABDEN bit is set, TXREG cannot be written to. Users should also ensure that ABDEN does not become set during a transmit sequence. Failing to do this may result in unpredictable EUSART operation. Note 1: If the WUE bit is set with the ABDEN bit, Auto-Baud Rate Detection will occur on the byte following the Break character. 2: It is up to the user to determine that the incoming character baud rate is within the range of the selected BRG clock source. Some combinations of oscillator frequency and EUSART baud rates are not possible due to bit error rates. Overall system timing and communication baud rates must be taken into consideration when using the Auto-Baud Rate Detection feature. BRG16 BRGH BRG Counter Clock 0 0 FOSC/512 0 1 FOSC/128 1 0 FOSC/128 1 1 FOSC/32 Note: During the ABD sequence, SPBRG and SPBRGH are both used as a 16-bit counter, independent of BRG16 setting.PIC18F2420/2520/4420/4520 DS39631E-page 210 © 2008 Microchip Technology Inc. FIGURE 18-1: AUTOMATIC BAUD RATE CALCULATION FIGURE 18-2: BRG OVERFLOW SEQUENCE BRG Value RX pin ABDEN bit RCIF bit Bit 0 Bit 1 (Interrupt) Read RCREG BRG Clock Start Set by User Auto-Cleared XXXXh 0000h Edge #1 Bit 2 Bit 3 Edge #2 Bit 4 Bit 5 Edge #3 Bit 6 Bit 7 Edge #4 Stop Bit Edge #5 001Ch Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0. SPBRG XXXXh 1Ch SPBRGH XXXXh 00h Start Bit 0 XXXXh 0000h 0000h FFFFh BRG Clock ABDEN bit RX pin ABDOVF bit BRG Value© 2008 Microchip Technology Inc. DS39631E-page 211 PIC18F2420/2520/4420/4520 18.2 EUSART Asynchronous Mode The Asynchronous mode of operation is selected by clearing the SYNC bit (TXSTA<4>). In this mode, the EUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop bit). The most common data format is 8 bits. An on-chip, dedicated 8-bit/16-bit Baud Rate Generator can be used to derive standard baud rate frequencies from the oscillator. The EUSART transmits and receives the LSb first. The EUSART’s transmitter and receiver are functionally independent but use the same data format and baud rate. The Baud Rate Generator produces a clock, either x16 or x64 of the bit shift rate depending on the BRGH and BRG16 bits (TXSTA<2> and BAUDCON<3>). Parity is not supported by the hardware but can be implemented in software and stored as the 9th data bit. When operating in Asynchronous mode, the EUSART module consists of the following important elements: • Baud Rate Generator • Sampling Circuit • Asynchronous Transmitter • Asynchronous Receiver • Auto-Wake-up on Sync Break Character • 12-Bit Break Character Transmit • Auto-Baud Rate Detection 18.2.1 EUSART ASYNCHRONOUS TRANSMITTER The EUSART transmitter block diagram is shown in Figure 18-3. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the Stop bit has been transmitted from the previous load. As soon as the Stop bit is transmitted, the TSR is loaded with new data from the TXREG register (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCY), the TXREG register is empty and the TXIF flag bit (PIR1<4>) is set. This interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TXIE (PIE1<4>). TXIF will be set regardless of the state of TXIE; it cannot be cleared in software. TXIF is also not cleared immediately upon loading TXREG, but becomes valid in the second instruction cycle following the load instruction. Polling TXIF immediately following a load of TXREG will return invalid results. While TXIF indicates the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR register is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. To set up an Asynchronous Transmission: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. 3. If interrupts are desired, set enable bit, TXIE. 4. If 9-bit transmission is desired, set transmit bit, TX9. Can be used as address/data bit. 5. Enable the transmission by setting bit, TXEN, which will also set bit, TXIF. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. 7. Load data to the TXREG register (starts transmission). 8. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 18-3: EUSART TRANSMIT BLOCK DIAGRAM Note 1: The TSR register is not mapped in data memory so it is not available to the user. 2: Flag bit, TXIF, is set when enable bit, TXEN, is set. TXIF TXIE Interrupt TXEN Baud Rate CLK SPBRG Baud Rate Generator TX9D MSb LSb Data Bus TXREG Register TSR Register (8) 0 TX9 TRMT SPEN TX pin Pin Buffer and Control 8 • • • BRG16 SPBRGHPIC18F2420/2520/4420/4520 DS39631E-page 212 © 2008 Microchip Technology Inc. FIGURE 18-4: ASYNCHRONOUS TRANSMISSION FIGURE 18-5: ASYNCHRONOUS TRANSMISSION (BACK TO BACK) TABLE 18-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 TXREG EUSART Transmit Register 51 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission. Note 1: Reserved in 28-pin devices; always maintain these bits clear. Word 1 Word 1 Transmit Shift Reg Start bit bit 0 bit 1 bit 7/8 Write to TXREG BRG Output (Shift Clock) TX (pin) TXIF bit (Transmit Buffer Reg. Empty Flag) TRMT bit (Transmit Shift Reg. Empty Flag) 1 TCY Stop bit Word 1 Transmit Shift Reg. Write to TXREG BRG Output (Shift Clock) TX (pin) TXIF bit (Interrupt Reg. Flag) TRMT bit (Transmit Shift Reg. Empty Flag) Word 1 Word 2 Word 1 Word 2 Stop bit Start bit Transmit Shift Reg. Word 1 Word 2 bit 0 bit 1 bit 7/8 bit 0 Note: This timing diagram shows two consecutive transmissions. 1 TCY 1 TCY Start bit© 2008 Microchip Technology Inc. DS39631E-page 213 PIC18F2420/2520/4420/4520 18.2.2 EUSART ASYNCHRONOUS RECEIVER The receiver block diagram is shown in Figure 18-6. The data is received on the RX pin and drives the data recovery block. The data recovery block is actually a high-speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. To set up an Asynchronous Reception: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. 3. If interrupts are desired, set enable bit, RCIE. 4. If 9-bit reception is desired, set bit, RX9. 5. Enable the reception by setting bit, CREN. 6. Flag bit, RCIF, will be set when reception is complete and an interrupt will be generated if enable bit, RCIE, was set. 7. Read the RCSTA register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG register. 9. If any error occurred, clear the error by clearing enable bit, CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 18.2.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RCIP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RCIF bit will be set when reception is complete. The interrupt will be Acknowledged if the RCIE and GIE bits are set. 8. Read the RCSTA register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU. FIGURE 18-6: EUSART RECEIVE BLOCK DIAGRAM x64 Baud Rate CLK Baud Rate Generator RX Pin Buffer and Control SPEN Data Recovery CREN OERR FERR MSb RSR Register LSb RX9D RCREG Register FIFO Interrupt RCIF RCIE Data Bus 8 ÷ 64 ÷ 16 or Stop (8) 7 1 0 Start RX9 • • • BRG16 SPBRGH SPBRG or ÷ 4PIC18F2420/2520/4420/4520 DS39631E-page 214 © 2008 Microchip Technology Inc. FIGURE 18-7: ASYNCHRONOUS RECEPTION TABLE 18-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION 18.2.4 AUTO-WAKE-UP ON SYNC BREAK CHARACTER During Sleep mode, all clocks to the EUSART are suspended. Because of this, the Baud Rate Generator is inactive and a proper byte reception cannot be performed. The auto-wake-up feature allows the controller to wake-up due to activity on the RX/DT line while the EUSART is operating in Asynchronous mode. The auto-wake-up feature is enabled by setting the WUE bit (BAUDCON<1>). Once set, the typical receive sequence on RX/DT is disabled and the EUSART remains in an Idle state, monitoring for a wake-up event independent of the CPU mode. A wake-up event consists of a high-to-low transition on the RX/DT line. (This coincides with the start of a Sync Break or a Wake-up Signal character for the LIN protocol.) Following a wake-up event, the module generates an RCIF interrupt. The interrupt is generated synchronously to the Q clocks in normal operating modes (Figure 18-8) and asynchronously, if the device is in Sleep mode (Figure 18-9). The interrupt condition is cleared by reading the RCREG register. The WUE bit is automatically cleared once a low-tohigh transition is observed on the RX line following the wake-up event. At this point, the EUSART module is in Idle mode and returns to normal operation. This signals to the user that the Sync Break event is over. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 RCREG EUSART Receive Register 51 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception. Note 1: Reserved in 28-pin devices; always maintain these bits clear. Start bit bit 0 bit 7/8 bit 1 Stop bit 0 bit 7/8 bit Start bit Start bit 7/8 Stop bit bit RX (pin) Rcv Buffer Reg Rcv Shift Reg Read Rcv Buffer Reg RCREG RCIF (Interrupt Flag) OERR bit CREN Word 1 RCREG Word 2 RCREG Stop bit Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word causing the OERR (overrun) bit to be set.© 2008 Microchip Technology Inc. DS39631E-page 215 PIC18F2420/2520/4420/4520 18.2.4.1 Special Considerations Using Auto-Wake-up Since auto-wake-up functions by sensing rising edge transitions on RX/DT, information with any state changes before the Stop bit may signal a false End-ofCharacter (EOC) and cause data or framing errors. To work properly, therefore, the initial character in the transmission must be all ‘0’s. This can be 00h (8 bytes) for standard RS-232 devices or 000h (12 bits) for LIN bus. Oscillator start-up time must also be considered, especially in applications using oscillators with longer start-up intervals (i.e., XT or HS mode). The Sync Break (or Wake-up Signal) character must be of sufficient length and be followed by a sufficient interval to allow enough time for the selected oscillator to start and provide proper initialization of the EUSART. 18.2.4.2 Special Considerations Using the WUE Bit The timing of WUE and RCIF events may cause some confusion when it comes to determining the validity of received data. As noted, setting the WUE bit places the EUSART in an Idle mode. The wake-up event causes a receive interrupt by setting the RCIF bit. The WUE bit is cleared after this when a rising edge is seen on RX/DT. The interrupt condition is then cleared by reading the RCREG register. Ordinarily, the data in RCREG will be dummy data and should be discarded. The fact that the WUE bit has been cleared (or is still set) and the RCIF flag is set should not be used as an indicator of the integrity of the data in RCREG. Users should consider implementing a parallel method in firmware to verify received data integrity. To assure that no actual data is lost, check the RCIDL bit to verify that a receive operation is not in process. If a receive operation is not occurring, the WUE bit may then be set just prior to entering the Sleep mode. FIGURE 18-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION FIGURE 18-9: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 WUE bit(1) RX/DT Line RCIF Note 1: The EUSART remains in Idle while the WUE bit is set. Bit Set by User Cleared Due to User Read of RCREG Auto-Cleared Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 WUE bit(2) RX/DT Line RCIF Bit Set by User Cleared Due to User Read of RCREG Sleep Command Executed Note 1: If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur before the oscillator is ready. This sequence should not depend on the presence of Q clocks. 2: The EUSART remains in Idle while the WUE bit is set. Sleep Ends Note 1 Auto-ClearedPIC18F2420/2520/4420/4520 DS39631E-page 216 © 2008 Microchip Technology Inc. 18.2.5 BREAK CHARACTER SEQUENCE The EUSART module has the capability of sending the special Break character sequences that are required by the LIN bus standard. The Break character transmit consists of a Start bit, followed by twelve ‘0’ bits and a Stop bit. The frame Break character is sent whenever the SENDB and TXEN bits (TXSTA<3> and TXSTA<5>) are set while the Transmit Shift register is loaded with data. Note that the value of data written to TXREG will be ignored and all ‘0’s will be transmitted. The SENDB bit is automatically reset by hardware after the corresponding Stop bit is sent. This allows the user to preload the transmit FIFO with the next transmit byte following the Break character (typically, the Sync character in the LIN specification). Note that the data value written to the TXREG for the Break character is ignored. The write simply serves the purpose of initiating the proper sequence. The TRMT bit indicates when the transmit operation is active or Idle, just as it does during normal transmission. See Figure 18-10 for the timing of the Break character sequence. 18.2.5.1 Break and Sync Transmit Sequence The following sequence will send a message frame header made up of a Break, followed by an Auto-Baud Sync byte. This sequence is typical of a LIN bus master. 1. Configure the EUSART for the desired mode. 2. Set the TXEN and SENDB bits to set up the Break character. 3. Load the TXREG with a dummy character to initiate transmission (the value is ignored). 4. Write ‘55h’ to TXREG to load the Sync character into the transmit FIFO buffer. 5. After the Break has been sent, the SENDB bit is reset by hardware. The Sync character now transmits in the preconfigured mode. When the TXREG becomes empty, as indicated by the TXIF, the next data byte can be written to TXREG. 18.2.6 RECEIVING A BREAK CHARACTER The Enhanced USART module can receive a Break character in two ways. The first method forces configuration of the baud rate at a frequency of 9/13 the typical speed. This allows for the Stop bit transition to be at the correct sampling location (13 bits for Break versus Start bit and 8 data bits for typical data). The second method uses the auto-wake-up feature described in Section 18.2.4 “Auto-Wake-up on Sync Break Character”. By enabling this feature, the EUSART will sample the next two transitions on RX/DT, cause an RCIF interrupt and receive the next data byte followed by another interrupt. Note that following a Break character, the user will typically want to enable the Auto-Baud Rate Detect feature. For both methods, the user can set the ABD bit once the TXIF interrupt is observed. FIGURE 18-10: SEND BREAK CHARACTER SEQUENCE Write to TXREG BRG Output (Shift Clock) Start Bit Bit 0 Bit 1 Bit 11 Stop Bit Break TXIF bit (Transmit Buffer Reg. Empty Flag) TX (pin) TRMT bit (Transmit Shift Reg. Empty Flag) SENDB (Transmit Shift Reg. Empty Flag) SENDB Sampled Here Auto-Cleared Dummy Write © 2008 Microchip Technology Inc. DS39631E-page 217 PIC18F2420/2520/4420/4520 18.3 EUSART Synchronous Master Mode The Synchronous Master mode is entered by setting the CSRC bit (TXSTA<7>). In this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit, SYNC (TXSTA<4>). In addition, enable bit, SPEN (RCSTA<7>), is set in order to configure the TX and RX pins to CK (clock) and DT (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK line. Clock polarity is selected with the TXCKP bit (BAUDCON<4>); setting TXCKP sets the Idle state on CK as high, while clearing the bit sets the Idle state as low. This option is provided to support Microwire devices with this module. 18.3.1 EUSART SYNCHRONOUS MASTER TRANSMISSION The EUSART transmitter block diagram is shown in Figure 18-3. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCY), the TXREG is empty and the TXIF flag bit (PIR1<4>) is set. The interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TXIE (PIE1<4>). TXIF is set regardless of the state of enable bit, TXIE; it cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit, TXIF, indicates the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory so it is not available to the user. To set up a Synchronous Master Transmission: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRG16 bit, as required, to achieve the desired baud rate. 2. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. 3. If interrupts are desired, set enable bit, TXIE. 4. If 9-bit transmission is desired, set bit, TX9. 5. Enable the transmission by setting bit, TXEN. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. 7. Start transmission by loading data to the TXREG register. 8. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 18-11: SYNCHRONOUS TRANSMISSION bit 0 bit 1 bit 7 Word 1 Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3Q4 Q1 Q2Q3Q4 Q1 Q2Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 bit 2 bit 0 bit 1 bit 7 RC7/RX/DT RC6/TX/CK pin Write to TXREG Reg TXIF bit (Interrupt Flag) TXEN bit ‘1’ ‘1’ Word 2 TRMT bit Write Word 1 Write Word 2 Note: Sync Master mode, SPBRG = 0, continuous transmission of two 8-bit words. RC6/TX/CK pin (TXCKP = 0) (TXCKP = 1)PIC18F2420/2520/4420/4520 DS39631E-page 218 © 2008 Microchip Technology Inc. FIGURE 18-12: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) TABLE 18-7: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 TXREG EUSART Transmit Register 51 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission. Note 1: Reserved in 28-pin devices; always maintain these bits clear. RC7/RX/DT pin RC6/TX/CK pin Write to TXREG reg TXIF bit TRMT bit bit 0 bit 1 bit 2 bit 6 bit 7 TXEN bit© 2008 Microchip Technology Inc. DS39631E-page 219 PIC18F2420/2520/4420/4520 18.3.2 EUSART SYNCHRONOUS MASTER RECEPTION Once Synchronous mode is selected, reception is enabled by setting either the Single Receive Enable bit, SREN (RCSTA<5>), or the Continuous Receive Enable bit, CREN (RCSTA<4>). Data is sampled on the RX pin on the falling edge of the clock. If enable bit, SREN, is set, only a single word is received. If enable bit, CREN, is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. Initialize the SPBRGH:SPBRG registers for the appropriate baud rate. Set or clear the BRG16 bit, as required, to achieve the desired baud rate. 2. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. 3. Ensure bits, CREN and SREN, are clear. 4. If interrupts are desired, set enable bit, RCIE. 5. If 9-bit reception is desired, set bit, RX9. 6. If a single reception is required, set bit, SREN. For continuous reception, set bit, CREN. 7. Interrupt flag bit, RCIF, will be set when reception is complete and an interrupt will be generated if the enable bit, RCIE, was set. 8. Read the RCSTA register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG register. 10. If any error occurred, clear the error by clearing bit, CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 18-13: SYNCHRONOUS RECEPTION (MASTER MODE, SREN) TABLE 18-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 RCREG EUSART Receive Register 51 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception. Note 1: Reserved in 28-pin devices; always maintain these bits clear. CREN bit RC7/RX/DT RC6/TX/CK pin Write to bit SREN SREN bit RCIF bit (Interrupt) Read RXREG Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 ‘0’ bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 ‘0’ Q1 Q2 Q3 Q4 Note: Timing diagram demonstrates Sync Master mode with bit, SREN = 1, and bit, BRGH = 0. RC6/TX/CK pin pin (TXCKP = 0) (TXCKP = 1)PIC18F2420/2520/4420/4520 DS39631E-page 220 © 2008 Microchip Technology Inc. 18.4 EUSART Synchronous Slave Mode Synchronous Slave mode is entered by clearing bit, CSRC (TXSTA<7>). This mode differs from the Synchronous Master mode in that the shift clock is supplied externally at the CK pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in any low-power mode. 18.4.1 EUSART SYNCHRONOUS SLAVE TRANSMISSION The operation of the Synchronous Master and Slave modes is identical, except in the case of the Sleep mode. If two words are written to the TXREG and then the SLEEP instruction is executed, the following will occur: a) The first word will immediately transfer to the TSR register and transmit. b) The second word will remain in the TXREG register. c) Flag bit, TXIF, will not be set. d) When the first word has been shifted out of TSR, the TXREG register will transfer the second word to the TSR and flag bit, TXIF, will now be set. e) If enable bit, TXIE, is set, the interrupt will wake the chip from Sleep. If the global interrupt is enabled, the program will branch to the interrupt vector. To set up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. 2. Clear bits, CREN and SREN. 3. If interrupts are desired, set enable bit, TXIE. 4. If 9-bit transmission is desired, set bit, TX9. 5. Enable the transmission by setting enable bit, TXEN. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. 7. Start transmission by loading data to the TXREG register. 8. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 18-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 TXREG EUSART Transmit Register 51 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission. Note 1: Reserved in 28-pin devices; always maintain these bits clear.© 2008 Microchip Technology Inc. DS39631E-page 221 PIC18F2420/2520/4420/4520 18.4.2 EUSART SYNCHRONOUS SLAVE RECEPTION The operation of the Synchronous Master and Slave modes is identical, except in the case of Sleep, or any Idle mode and bit, SREN, which is a “don’t care” in Slave mode. If receive is enabled by setting the CREN bit prior to entering Sleep or any Idle mode, then a word may be received while in this low-power mode. Once the word is received, the RSR register will transfer the data to the RCREG register; if the RCIE enable bit is set, the interrupt generated will wake the chip from the low-power mode. If the global interrupt is enabled, the program will branch to the interrupt vector. To set up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. 2. If interrupts are desired, set enable bit, RCIE. 3. If 9-bit reception is desired, set bit, RX9. 4. To enable reception, set enable bit, CREN. 5. Flag bit, RCIF, will be set when reception is complete. An interrupt will be generated if enable bit, RCIE, was set. 6. Read the RCSTA register to get the 9th bit (if enabled) and determine if any error occurred during reception. 7. Read the 8-bit received data by reading the RCREG register. 8. If any error occurred, clear the error by clearing bit, CREN. 9. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 18-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 51 RCREG EUSART Receive Register 51 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 51 BAUDCON ABDOVF RCIDL RXDTP TXCKP BRG16 — WUE ABDEN 51 SPBRGH EUSART Baud Rate Generator Register High Byte 51 SPBRG EUSART Baud Rate Generator Register Low Byte 51 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception. Note 1: Reserved in 28-pin devices; always maintain these bits clear.PIC18F2420/2520/4420/4520 DS39631E-page 222 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 223 PIC18F2420/2520/4420/4520 19.0 10-BIT ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE The Analog-to-Digital (A/D) Converter module has 10 inputs for the 28-pin devices and 13 for the 40/44-pin devices. This module allows conversion of an analog input signal to a corresponding 10-bit digital number. The module has five registers: • A/D Result High Register (ADRESH) • A/D Result Low Register (ADRESL) • A/D Control Register 0 (ADCON0) • A/D Control Register 1 (ADCON1) • A/D Control Register 2 (ADCON2) The ADCON0 register, shown in Register 19-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 19-2, configures the functions of the port pins. The ADCON2 register, shown in Register 19-3, configures the A/D clock source, programmed acquisition time and justification. REGISTER 19-1: ADCON0: A/D CONTROL REGISTER 0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — CHS3 CHS2 CHS1 CHS0 GO/DONE ADON bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-6 Unimplemented: Read as ‘0’ bit 5-2 CHS<3:0>: Analog Channel Select bits 0000 = Channel 0 (AN0) 0001 = Channel 1 (AN1) 0010 = Channel 2 (AN2) 0011 = Channel 3 (AN3) 0100 = Channel 4 (AN4) 0101 = Channel 5 (AN5)(1,2) 0110 = Channel 6 (AN6)(1,2) 0111 = Channel 7 (AN7)(1,2) 1000 = Channel 8 (AN8) 1001 = Channel 9 (AN9) 1010 = Channel 10 (AN10) 1011 = Channel 11 (AN11) 1100 = Channel 12 (AN12) 1101 = Unimplemented)(2) 1110 = Unimplemented)(2) 1111 = Unimplemented)(2) bit 1 GO/DONE: A/D Conversion Status bit When ADON = 1: 1 = A/D conversion in progress 0 = A/D Idle bit 0 ADON: A/D On bit 1 = A/D Converter module is enabled 0 = A/D Converter module is disabled Note 1: These channels are not implemented on 28-pin devices. 2: Performing a conversion on unimplemented channels will return a floating input measurement.PIC18F2420/2520/4420/4520 DS39631E-page 224 © 2008 Microchip Technology Inc. REGISTER 19-2: ADCON1: A/D CONTROL REGISTER 1 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-q(1) R/W-q(1) R/W-q(1) — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-6 Unimplemented: Read as ‘0’ bit 5 VCFG1: Voltage Reference Configuration bit (VREF- source) 1 = VREF- (AN2) 0 = VSS bit 4 VCFG0: Voltage Reference Configuration bit (VREF+ source) 1 = VREF+ (AN3) 0 = VDD bit 3-0 PCFG<3:0>: A/D Port Configuration Control bits: Note 1: The POR value of the PCFG bits depends on the value of the PBADEN Configuration bit. When PBADEN = 1, PCFG<2:0> = 000; when PBADEN = 0, PCFG<2:0> = 111. 2: AN5 through AN7 are available only on 40/44-pin devices. A = Analog input D = Digital I/O PCFG3: PCFG0 AN12 AN11 AN10 AN9 AN8 AN7(2) AN6(2) AN5(2) AN4 AN3 AN2 AN1 AN0 0000(1) A A A A A A A A A AAAA 0001 A A A A A A A A A AAAA 0010 A A A A A A A A A AAAA 0011 D A A A A A A A A AAAA 0100 D D A A A A A A A AAAA 0101 D D D A A A A A A AAAA 0110 D D D D A A A A A AAAA 0111(1) D D D D D A A A A AAAA 1000 D D D D D D A A A AAAA 1001 D D D D D D D A A AAAA 1010 D D D D D D D D A AAAA 1011 D D D D D D D D D AAAA 1100 D D D D D D D D D DAAA 1101 D D D D D D D D D DDAA 1110 D D D D D D D D D DDDA 1111 D D D D D D D D D DDDD© 2008 Microchip Technology Inc. DS39631E-page 225 PIC18F2420/2520/4420/4520 REGISTER 19-3: ADCON2: A/D CONTROL REGISTER 2 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 ADFM: A/D Result Format Select bit 1 = Right justified 0 = Left justified bit 6 Unimplemented: Read as ‘0’ bit 5-3 ACQT<2:0>: A/D Acquisition Time Select bits 111 = 20 TAD 110 = 16 TAD 101 = 12 TAD 100 = 8 TAD 011 = 6 TAD 010 = 4 TAD 001 = 2 TAD 000 = 0 TAD(1) bit 2-0 ADCS<2:0>: A/D Conversion Clock Select bits 111 = FRC (clock derived from A/D RC oscillator)(1) 110 = FOSC/64 101 = FOSC/16 100 = FOSC/4 011 = FRC (clock derived from A/D RC oscillator)(1) 010 = FOSC/32 001 = FOSC/8 000 = FOSC/2 Note 1: If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D clock starts. This allows the SLEEP instruction to be executed before starting a conversion.PIC18F2420/2520/4420/4520 DS39631E-page 226 © 2008 Microchip Technology Inc. The analog reference voltage is software selectable to either the device’s positive and negative supply voltage (VDD and VSS), or the voltage level on the RA3/AN3/ VREF+ and RA2/AN2/VREF-/CVREF pins. The A/D Converter has a unique feature of being able to operate while the device is in Sleep mode. To operate in Sleep, the A/D conversion clock must be derived from the A/D’s internal RC oscillator. The output of the sample and hold is the input into the converter, which generates the result via successive approximation. A device Reset forces all registers to their Reset state. This forces the A/D module to be turned off and any conversion in progress is aborted. Each port pin associated with the A/D Converter can be configured as an analog input, or as a digital I/O. The ADRESH and ADRESL registers contain the result of the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH:ADRESL register pair, the GO/DONE bit (ADCON0 register) is cleared and the A/D Interrupt Flag bit, ADIF, is set. The block diagram of the A/D module is shown in Figure 19-1. FIGURE 19-1: A/D BLOCK DIAGRAM (Input Voltage) VAIN VREF+ Reference Voltage VDD(2) VCFG<1:0> CHS<3:0> AN7(1) AN6(1) AN5(1) AN4 AN3 AN2 AN1 AN0 0111 0110 0101 0100 0011 0010 0001 0000 10-Bit A/D VREFVSS(2) Converter AN12 AN11 AN10 AN9 AN8 1100 1011 1010 1001 1000 Note 1: Channels, AN5 through AN7, are not available on 28-pin devices. 2: I/O pins have diode protection to VDD and VSS. 0X 1X X1 X0© 2008 Microchip Technology Inc. DS39631E-page 227 PIC18F2420/2520/4420/4520 The value in the ADRESH:ADRESL registers is not modified for a Power-on Reset. The ADRESH:ADRESL registers will contain unknown data after a Power-on Reset. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as an input. To determine acquisition time, see Section 19.1 “A/D Acquisition Requirements”. After this acquisition time has elapsed, the A/D conversion can be started. An acquisition time can be programmed to occur between setting the GO/DONE bit and the actual start of the conversion. The following steps should be followed to perform an A/D conversion: 1. Configure the A/D module: • Configure analog pins, voltage reference and digital I/O (ADCON1) • Select A/D input channel (ADCON0) • Select A/D acquisition time (ADCON2) • Select A/D conversion clock (ADCON2) • Turn on A/D module (ADCON0) 2. Configure A/D interrupt (if desired): • Clear ADIF bit • Set ADIE bit • Set GIE bit 3. Wait the required acquisition time (if required). 4. Start conversion: • Set GO/DONE bit (ADCON0 register) 5. Wait for A/D conversion to complete, by either: • Polling for the GO/DONE bit to be cleared OR • Waiting for the A/D interrupt 6. Read A/D Result registers (ADRESH:ADRESL); clear bit, ADIF, if required. 7. For next conversion, go to step 1 or step 2, as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2 TAD is required before the next acquisition starts. FIGURE 19-2: A/D TRANSFER FUNCTION FIGURE 19-3: ANALOG INPUT MODEL Digital Code Output 3FEh 003h 002h 001h 000h 0.5 LSB 1 LSB 1.5 LSB 2 LSB 2.5 LSB 1022 LSB 1022.5 LSB 3 LSB Analog Input Voltage 3FFh 1023 LSB 1023.5 LSB VAIN CPIN Rs ANx 5 pF VT = 0.6V VT = 0.6V ILEAKAGE RIC ≤ 1k Sampling Switch SS RSS CHOLD = 25 pF VSS VDD ±100 nA Legend: CPIN VT ILEAKAGE RIC SS CHOLD = Input Capacitance = Threshold Voltage = Leakage Current at the pin due to = Interconnect Resistance = Sampling Switch = Sample/Hold Capacitance (from DAC) various junctions RSS = Sampling Switch Resistance VDD 6V Sampling Switch 5V 4V 3V 2V 1 23 4 (kΩ)PIC18F2420/2520/4420/4520 DS39631E-page 228 © 2008 Microchip Technology Inc. 19.1 A/D Acquisition Requirements For the A/D Converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 19-3. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD). The source impedance affects the offset voltage at the analog input (due to pin leakage current). The maximum recommended impedance for analog sources is 2.5 kΩ. After the analog input channel is selected (changed), the channel must be sampled for at least the minimum acquisition time before starting a conversion. To calculate the minimum acquisition time, Equation 19-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. Example 19-3 shows the calculation of the minimum required acquisition time TACQ. This calculation is based on the following application system assumptions: CHOLD = 25 pF Rs = 2.5 kΩ Conversion Error ≤ 1/2 LSb VDD = 5V → Rss = 2 kΩ Temperature = 85°C (system max.) EQUATION 19-1: ACQUISITION TIME EQUATION 19-2: A/D MINIMUM CHARGING TIME EQUATION 19-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME Note: When the conversion is started, the holding capacitor is disconnected from the input pin. TACQ = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient = TAMP + TC + TCOFF VHOLD = (VREF – (VREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS))) or TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048) TACQ =TAMP + TC + TCOFF TAMP = 0.2 μs TCOFF = (Temp – 25°C)(0.02 μs/°C) (85°C – 25°C)(0.02 μs/°C) 1.2 μs Temperature coefficient is only required for temperatures > 25°C. Below 25°C, TCOFF = 0 μs. TC = -(CHOLD)(RIC + RSS + RS) ln(1/2047) μs -(25 pF) (1 kΩ + 2 kΩ + 2.5 kΩ) ln(0.0004883) μs 1.05 μs TACQ = 0.2 μs + 1 μs + 1.2 μs 2.4 μs© 2008 Microchip Technology Inc. DS39631E-page 229 PIC18F2420/2520/4420/4520 19.2 Selecting and Configuring Acquisition Time The ADCON2 register allows the user to select an acquisition time that occurs each time the GO/DONE bit is set. It also gives users the option to use an automatically determined acquisition time. Acquisition time may be set with the ACQT<2:0> bits (ADCON2<5:3>), which provides a range of 2 to 20 TAD. When the GO/DONE bit is set, the A/D module continues to sample the input for the selected acquisition time, then automatically begins a conversion. Since the acquisition time is programmed, there may be no need to wait for an acquisition time between selecting a channel and setting the GO/DONE bit. Manual acquisition is selected when ACQT<2:0> = 000. When the GO/DONE bit is set, sampling is stopped and a conversion begins. The user is responsible for ensuring the required acquisition time has passed between selecting the desired input channel and setting the GO/DONE bit. This option is also the default Reset state of the ACQT<2:0> bits and is compatible with devices that do not offer programmable acquisition times. In either case, when the conversion is completed, the GO/DONE bit is cleared, the ADIF flag is set and the A/D begins sampling the currently selected channel again. If an acquisition time is programmed, there is nothing to indicate if the acquisition time has ended or if the conversion has begun. 19.3 Selecting the A/D Conversion Clock The A/D conversion time per bit is defined as TAD. The A/D conversion requires 11 TAD per 10-bit conversion. The source of the A/D conversion clock is software selectable. There are seven possible options for TAD: • 2 TOSC • 4 TOSC • 8 TOSC • 16 TOSC • 32 TOSC • 64 TOSC • Internal RC Oscillator For correct A/D conversions, the A/D conversion clock (TAD) must be as short as possible, but greater than the minimum TAD (see parameter 130 for more information). Table 19-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. TABLE 19-1: TAD vs. DEVICE OPERATING FREQUENCIES AD Clock Source (TAD) Maximum Device Frequency Operation ADCS<2:0> PIC18F2X20/4X20 PIC18LF2X2X/4X20(4) 2 TOSC 000 2.86 MHz 1.43 kHz 4 TOSC 100 5.71 MHz 2.86 MHz 8 TOSC 001 11.43 MHz 5.72 MHz 16 TOSC 101 22.86 MHz 11.43 MHz 32 TOSC 010 40.0 MHz 22.86 MHz 64 TOSC 110 40.0 MHz 22.86 MHz RC(3) x11 1.00 MHz(1) 1.00 MHz(2) Note 1: The RC source has a typical TAD time of 1.2 μs. 2: The RC source has a typical TAD time of 2.5 μs. 3: For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or the A/D accuracy may be out of specification. 4: Low-power (PIC18LFXXXX) devices only.PIC18F2420/2520/4420/4520 DS39631E-page 230 © 2008 Microchip Technology Inc. 19.4 Operation in Power-Managed Modes The selection of the automatic acquisition time and A/D conversion clock is determined in part by the clock source and frequency while in a power-managed mode. If the A/D is expected to operate while the device is in a power-managed mode, the ACQT<2:0> and ADCS<2:0> bits in ADCON2 should be updated in accordance with the clock source to be used in that mode. After entering the mode, an A/D acquisition or conversion may be started. Once started, the device should continue to be clocked by the same clock source until the conversion has been completed. If desired, the device may be placed into the corresponding Idle mode during the conversion. If the device clock frequency is less than 1 MHz, the A/D RC clock source should be selected. Operation in Sleep mode requires the A/D FRC clock to be selected. If the ACQT<2:0> bits are set to ‘000’ and a conversion is started, the conversion will be delayed one instruction cycle to allow execution of the SLEEP instruction and entry to Sleep mode. The IDLEN bit (OSCCON<7>) must have already been cleared prior to starting the conversion. 19.5 Configuring Analog Port Pins The ADCON1, TRISA, TRISB and TRISE registers all configure the A/D port pins. The port pins needed as analog inputs must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS<3:0> bits and the TRIS bits. Note 1: When reading the PORT register, all pins configured as analog input channels will read as cleared (a low level). Pins configured as digital inputs will convert as analog inputs. Analog levels on a digitally configured input will be accurately converted. 2: Analog levels on any pin defined as a digital input may cause the digital input buffer to consume current out of the device’s specification limits. 3: The PBADEN bit, in Configuration Register 3H, configures PORTB pins to reset as analog or digital pins by controlling how the PCFG bits in ADCON1 are reset.© 2008 Microchip Technology Inc. DS39631E-page 231 PIC18F2420/2520/4420/4520 19.6 A/D Conversions Figure 19-4 shows the operation of the A/D Converter after the GO/DONE bit has been set and the ACQT<2:0> bits are cleared. A conversion is started after the following instruction to allow entry into Sleep mode before the conversion begins. Figure 19-5 shows the operation of the A/D Converter after the GO/DONE bit has been set and the ACQT<2:0> bits are set to ‘010’, and selecting a 4 TAD acquisition time before the conversion starts. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D Result register pair will NOT be updated with the partially completed A/D conversion sample. This means the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is completed or aborted, a 2 TAD wait is required before the next acquisition can be started. After this wait, acquisition on the selected channel is automatically started. 19.7 Discharge The discharge phase is used to initialize the value of the capacitor array. The array is discharged before every sample. This feature helps to optimize the unitygain amplifier, as the circuit always needs to charge the capacitor array, rather than charge/discharge based on previous measure values. FIGURE 19-4: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0) FIGURE 19-5: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD) Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D. TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD11 Set GO/DONE bit Holding capacitor is disconnected from analog input (typically 100 ns) TCY - TAD TAD9 TAD10 ADRESH:ADRESL are loaded, GO/DONE bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. Conversion starts b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 On the following cycle: TAD1 Discharge 1 2 3 4 5 6 7 8 11 Set GO/DONE bit (Holding capacitor is disconnected) 9 10 Conversion starts 1 2 3 4 (Holding capacitor continues acquiring input) TACQT Cycles TAD Cycles Automatic Acquisition Time b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 ADRESH:ADRESL are loaded, GO/DONE bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. On the following cycle: TAD1 Discharge PIC18F2420/2520/4420/4520 DS39631E-page 232 © 2008 Microchip Technology Inc. 19.8 Use of the CCP2 Trigger An A/D conversion can be started by the Special Event Trigger of the CCP2 module. This requires that the CCP2M<3:0> bits (CCP2CON<3:0>) be programmed as ‘1011’ and that the A/D module is enabled (ADON bit is set). When the trigger occurs, the GO/DONE bit will be set, starting the A/D acquisition and conversion, and the Timer1 (or Timer3) counter will be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal software overhead (moving ADRESH:ADRESL to the desired location). The appropriate analog input channel must be selected and the minimum acquisition period is either timed by the user, or an appropriate TACQ time is selected before the Special Event Trigger sets the GO/DONE bit (starts a conversion). If the A/D module is not enabled (ADON is cleared), the Special Event Trigger will be ignored by the A/D module, but will still reset the Timer1 (or Timer3) counter. TABLE 19-2: REGISTERS ASSOCIATED WITH A/D OPERATION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 52 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 52 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 52 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 ADRESH A/D Result Register High Byte 51 ADRESL A/D Result Register Low Byte 51 ADCON0 — — CHS3 CHS2 CHS1 CHS0 GO/DONE ADON 51 ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 51 ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 51 PORTA RA7(2) RA6(2) RA5 RA4 RA3 RA2 RA1 RA0 52 TRISA TRISA7(2) TRISA6(2) PORTA Data Direction Register 52 PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 52 TRISB PORTB Data Direction Register 52 LATB PORTB Data Latch Register (Read and Write to Data Latch) 52 PORTE(4) — — — — RE3(3) RE2 RE1 RE0 52 TRISE(4) IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 52 LATE(4) — — — — — PORTE Data Latch Register 52 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion. Note 1: These bits are unimplemented on 28-pin devices; always maintain these bits clear. 2: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’. 3: RE3 port bit is available only as an input pin when the MCLRE Configuration bit is ‘0’. 4: These registers are not implemented on 28-pin devices.© 2008 Microchip Technology Inc. DS39631E-page 233 PIC18F2420/2520/4420/4520 20.0 COMPARATOR MODULE The analog comparator module contains two comparators that can be configured in a variety of ways. The inputs can be selected from the analog inputs multiplexed with pins, RA0 through RA5, as well as the on-chip voltage reference (see Section 21.0 “Comparator Voltage Reference Module”). The digital outputs (normal or inverted) are available at the pin level and can also be read through the control register. The CMCON register (Register 20-1) selects the comparator input and output configuration. Block diagrams of the various comparator configurations are shown in Figure 20-1. REGISTER 20-1: CMCON: COMPARATOR CONTROL REGISTER R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-1 C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 C2OUT: Comparator 2 Output bit When C2INV = 0: 1 = C2 VIN+ > C2 VIN- 0 = C2 VIN+ < C2 VINWhen C2INV = 1: 1 = C2 VIN+ < C2 VIN- 0 = C2 VIN+ > C2 VINbit 6 C1OUT: Comparator 1 Output bit When C1INV = 0: 1 = C1 VIN+ > C1 VIN- 0 = C1 VIN+ < C1 VINWhen C1INV = 1: 1 = C1 VIN+ < C1 VIN- 0 = C1 VIN+ > C1 VINbit 5 C2INV: Comparator 2 Output Inversion bit 1 = C2 output inverted 0 = C2 output not inverted bit 4 C1INV: Comparator 1 Output Inversion bit 1 = C1 output inverted 0 = C1 output not inverted bit 3 CIS: Comparator Input Switch bit When CM<2:0> = 110: 1 = C1 VIN- connects to RA3/AN3/VREF+ C2 VIN- connects to RA2/AN2/VREF-/CVREF 0 = C1 VIN- connects to RA0/AN0 C2 VIN- connects to RA1/AN1 bit 2-0 CM<2:0>: Comparator Mode bits Figure 20-1 shows the Comparator modes and the CM<2:0> bit settings.PIC18F2420/2520/4420/4520 DS39631E-page 234 © 2008 Microchip Technology Inc. 20.1 Comparator Configuration There are eight modes of operation for the comparators, shown in Figure 20-1. Bits CM<2:0> of the CMCON register are used to select these modes. The TRISA register controls the data direction of the comparator pins for each mode. If the Comparator mode is changed, the comparator output level may not be valid for the specified mode change delay shown in Section 26.0 “Electrical Characteristics”. FIGURE 20-1: COMPARATOR I/O OPERATING MODES Note: Comparator interrupts should be disabled during a Comparator mode change; otherwise, a false interrupt may occur. C1 RA0/AN0 VINVIN+ RA3/AN3/ Off (Read as ‘0’) Comparators Reset A A CM<2:0> = 000 C2 RA1/AN1 VINVIN+ RA2/AN2/ Off (Read as ‘0’) A A C1 VINVIN+ C1OUT Two Independent Comparators A A CM<2:0> = 010 C2 VINVIN+ C2OUT A A C1 VINVIN+ C1OUT Two Common Reference Comparators A A CM<2:0> = 100 C2 VINVIN+ C2OUT A D C2 VINVIN+ Off (Read as ‘0’) One Independent Comparator with Output D D CM<2:0> = 001 C1 VINVIN+ C1OUT A A C1 VINVIN+ Off (Read as ‘0’) Comparators Off (POR Default Value) D D CM<2:0> = 111 C2 VINVIN+ Off (Read as ‘0’) D D C1 VINVIN+ C1OUT Four Inputs Multiplexed to Two Comparators A A CM<2:0> = 110 C2 VINVIN+ C2OUT A A From VREF Module CIS = 0 CIS = 1 CIS = 0 CIS = 1 C1 VINVIN+ C1OUT Two Common Reference Comparators with Outputs A A CM<2:0> = 101 C2 VINVIN+ C2OUT A D A = Analog Input, port reads zeros always D = Digital Input CIS (CMCON<3>) is the Comparator Input Switch CVREF C1 VINVIN+ C1OUT Two Independent Comparators with Outputs A A CM<2:0> = 011 C2 VINVIN+ C2OUT A A RA5/AN4/SS/HLVDIN/C2OUT* RA4/T0CKI/C1OUT* VREF+ VREF-/CVREF RA0/AN0 RA3/AN3/ RA1/AN1 RA2/AN2/ VREF+ VREF-/CVREF RA0/AN0 RA3/AN3/ RA1/AN1 RA2/AN2/ VREF+ VREF-/CVREF RA0/AN0 RA3/AN3/ RA1/AN1 RA2/AN2/ VREF+ VREF-/CVREF RA0/AN0 RA3/AN3/ RA1/AN1 RA2/AN2/ VREF+ VREF-/CVREF RA0/AN0 RA3/AN3/ RA1/AN1 RA2/AN2/ VREF+ VREF-/CVREF RA0/AN0 RA3/AN3/ VREF+ RA1/AN1 RA2/AN2/ VREF-/CVREF RA4/T0CKI/C1OUT* RA5/AN4/SS/HLVDIN/C2OUT* RA0/AN0 RA3/AN3/ VREF+ RA1/AN1 RA2/AN2/ VREF-/CVREF RA4/T0CKI/C1OUT* * Setting the TRISA<5:4> bits will disable the comparator outputs by configuring the pins as inputs.© 2008 Microchip Technology Inc. DS39631E-page 235 PIC18F2420/2520/4420/4520 20.2 Comparator Operation A single comparator is shown in Figure 20-2, along with the relationship between the analog input levels and the digital output. When the analog input at VIN+ is less than the analog input VIN-, the output of the comparator is a digital low level. When the analog input at VIN+ is greater than the analog input VIN-, the output of the comparator is a digital high level. The shaded areas of the output of the comparator in Figure 20-2 represent the uncertainty, due to input offsets and response time. 20.3 Comparator Reference Depending on the comparator operating mode, either an external or internal voltage reference may be used. The analog signal present at VIN- is compared to the signal at VIN+ and the digital output of the comparator is adjusted accordingly (Figure 20-2). FIGURE 20-2: SINGLE COMPARATOR 20.3.1 EXTERNAL REFERENCE SIGNAL When external voltage references are used, the comparator module can be configured to have the comparators operate from the same or different reference sources. However, threshold detector applications may require the same reference. The reference signal must be between VSS and VDD and can be applied to either pin of the comparator(s). 20.3.2 INTERNAL REFERENCE SIGNAL The comparator module also allows the selection of an internally generated voltage reference from the comparator voltage reference module. This module is described in more detail in Section 21.0 “Comparator Voltage Reference Module”. The internal reference is only available in the mode where four inputs are multiplexed to two comparators (CM<2:0> = 110). In this mode, the internal voltage reference is applied to the VIN+ pin of both comparators. 20.4 Comparator Response Time Response time is the minimum time, after selecting a new reference voltage or input source, before the comparator output has a valid level. If the internal reference is changed, the maximum delay of the internal voltage reference must be considered when using the comparator outputs. Otherwise, the maximum delay of the comparators should be used (see Section 26.0 “Electrical Characteristics”). 20.5 Comparator Outputs The comparator outputs are read through the CMCON register. These bits are read-only. The comparator outputs may also be directly output to the RA4 and RA5 I/O pins. When enabled, multiplexers in the output path of the RA4 and RA5 pins will switch and the output of each pin will be the unsynchronized output of the comparator. The uncertainty of each of the comparators is related to the input offset voltage and the response time given in the specifications. Figure 20-3 shows the comparator output block diagram. The TRISA bits will still function as an output enable/ disable for the RA4 and RA5 pins while in this mode. The polarity of the comparator outputs can be changed using the C2INV and C1INV bits (CMCON<4:5>). – VIN+ + VINOutput Output VINVIN+ Note 1: When reading the PORT register, all pins configured as analog inputs will read as ‘0’. Pins configured as digital inputs will convert an analog input according to the Schmitt Trigger input specification. 2: Analog levels on any pin defined as a digital input may cause the input buffer to consume more current than is specified.PIC18F2420/2520/4420/4520 DS39631E-page 236 © 2008 Microchip Technology Inc. FIGURE 20-3: COMPARATOR OUTPUT BLOCK DIAGRAM 20.6 Comparator Interrupts The comparator interrupt flag is set whenever there is a change in the output value of either comparator. Software will need to maintain information about the status of the output bits, as read from CMCON<7:6>, to determine the actual change that occurred. The CMIF bit (PIR2<6>) is the Comparator Interrupt Flag. The CMIF bit must be reset by clearing it. Since it is also possible to write a ‘1’ to this register, a simulated interrupt may be initiated. Both the CMIE bit (PIE2<6>) and the PEIE bit (INTCON<6>) must be set to enable the interrupt. In addition, the GIE bit (INTCON<7>) must also be set. If any of these bits are clear, the interrupt is not enabled, though the CMIF bit will still be set if an interrupt condition occurs. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) Any read or write of CMCON will end the mismatch condition. b) Clear flag bit, CMIF. A mismatch condition will continue to set flag bit, CMIF. Reading CMCON will end the mismatch condition and allow flag bit, CMIF, to be cleared. 20.7 Comparator Operation During Sleep When a comparator is active and the device is placed in Sleep mode, the comparator remains active and the interrupt is functional if enabled. This interrupt will wake-up the device from Sleep mode when enabled. Each operational comparator will consume additional current, as shown in the comparator specifications. To minimize power consumption while in Sleep mode, turn off the comparators (CM<2:0> = 111) before entering Sleep. If the device wakes up from Sleep, the contents of the CMCON register are not affected. 20.8 Effects of a Reset A device Reset forces the CMCON register to its Reset state, causing the comparator modules to be turned off (CM<2:0> = 111). However, the input pins (RA0 through RA3) are configured as analog inputs by default on device Reset. The I/O configuration for these pins is determined by the setting of the PCFG<3:0> bits (ADCON1<3:0>). Therefore, device current is minimized when analog inputs are present at Reset time. D Q EN To RA4 or RA5 pin Bus Data Set MULTIPLEX CMIF bit - + Port pins Read CMCON Reset From Other Comparator CxINV D Q EN CL Note: If a change in the CMCON register (C1OUT or C2OUT) should occur when a read operation is being executed (start of the Q2 cycle), then the CMIF (PIR2<6>) interrupt flag may not get set.© 2008 Microchip Technology Inc. DS39631E-page 237 PIC18F2420/2520/4420/4520 20.9 Analog Input Connection Considerations A simplified circuit for an analog input is shown in Figure 20-4. Since the analog pins are connected to a digital output, they have reverse biased diodes to VDD and VSS. The analog input, therefore, must be between VSS and VDD. If the input voltage deviates from this range by more than 0.6V in either direction, one of the diodes is forward biased and a latch-up condition may occur. A maximum source impedance of 10 kΩ is recommended for the analog sources. Any external component connected to an analog input pin, such as a capacitor or a Zener diode, should have very little leakage current. FIGURE 20-4: COMPARATOR ANALOG INPUT MODEL TABLE 20-1: REGISTERS ASSOCIATED WITH COMPARATOR MODULE Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 51 CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 51 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 52 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OSCFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 PORTA RA7(1) RA6(1) RA5 RA4 RA3 RA2 RA1 RA0 52 LATA LATA7(1) LATA6(1) PORTA Data Latch Register (Read and Write to Data Latch) 52 TRISA TRISA7(1) TRISA6(1) PORTA Data Direction Register 52 Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module. Note 1: PORTA<7:6> and their direction and latch bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits are read as ‘0’. VA RS < 10k AIN CPIN 5 pF VDD VT = 0.6V VT = 0.6V RIC ILEAKAGE ±100 nA VSS Legend: CPIN = Input Capacitance VT = Threshold Voltage ILEAKAGE = Leakage Current at the pin due to various junctions RIC = Interconnect Resistance RS = Source Impedance VA = Analog Voltage Comparator InputPIC18F2420/2520/4420/4520 DS39631E-page 238 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 239 PIC18F2420/2520/4420/4520 21.0 COMPARATOR VOLTAGE REFERENCE MODULE The comparator voltage reference is a 16-tap resistor ladder network that provides a selectable reference voltage. Although its primary purpose is to provide a reference for the analog comparators, it may also be used independently of them. A block diagram of the module is shown in Figure 21-1. The resistor ladder is segmented to provide two ranges of CVREF values and has a power-down function to conserve power when the reference is not being used. The module’s supply reference can be provided from either device VDD/VSS or an external voltage reference. 21.1 Configuring the Comparator Voltage Reference The voltage reference module is controlled through the CVRCON register (Register 21-1). The comparator voltage reference provides two ranges of output voltage, each with 16 distinct levels. The range to be used is selected by the CVRR bit (CVRCON<5>). The primary difference between the ranges is the size of the steps selected by the CVREF Selection bits (CVR<3:0>), with one range offering finer resolution. The equations used to calculate the output of the comparator voltage reference are as follows: If CVRR = 1: CVREF = ((CVR<3:0>)/24) x CVRSRC If CVRR = 0: CVREF = (CVRSRC x 1/4) + (((CVR<3:0>)/32) x CVRSRC) The comparator reference supply voltage can come from either VDD and VSS, or the external VREF+ and VREF- that are multiplexed with RA2 and RA3. The voltage source is selected by the CVRSS bit (CVRCON<4>). The settling time of the comparator voltage reference must be considered when changing the CVREF output (see Table 26-3 in Section 26.0 “Electrical Characteristics”). REGISTER 21-1: CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 CVREN CVROE(1) CVRR CVRSS CVR3 CVR2 CVR1 CVR0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 CVREN: Comparator Voltage Reference Enable bit 1 = CVREF circuit powered on 0 = CVREF circuit powered down bit 6 CVROE: Comparator VREF Output Enable bit(1) 1 = CVREF voltage level is also output on the RA2/AN2/VREF-/CVREF pin 0 = CVREF voltage is disconnected from the RA2/AN2/VREF-/CVREF pin bit 5 CVRR: Comparator VREF Range Selection bit 1 = 0 to 0.667 CVRSRC, with CVRSRC/24 step size (low range) 0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size (high range) bit 4 CVRSS: Comparator VREF Source Selection bit 1 = Comparator reference source, CVRSRC = (VREF+) – (VREF-) 0 = Comparator reference source, CVRSRC = VDD – VSS bit 3-0 CVR3:CVR0: Comparator VREF Value Selection bits (0 ≤ (CVR<3:0>) ≤ 15) When CVRR = 1: CVREF = ((CVR<3:0>)/24) • (CVRSRC) When CVRR = 0: CVREF = (CVRSRC/4) + ((CVR<3:0>)/32) • (CVRSRC) Note 1: CVROE overrides the TRISA<2> bit setting.PIC18F2420/2520/4420/4520 DS39631E-page 240 © 2008 Microchip Technology Inc. FIGURE 21-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM 21.2 Voltage Reference Accuracy/Error The full range of voltage reference cannot be realized due to the construction of the module. The transistors on the top and bottom of the resistor ladder network (Figure 21-1) keep CVREF from approaching the reference source rails. The voltage reference is derived from the reference source; therefore, the CVREF output changes with fluctuations in that source. The tested absolute accuracy of the voltage reference can be found in Section 26.0 “Electrical Characteristics”. 21.3 Operation During Sleep When the device wakes up from Sleep through an interrupt or a Watchdog Timer time-out, the contents of the CVRCON register are not affected. To minimize current consumption in Sleep mode, the voltage reference should be disabled. 21.4 Effects of a Reset A device Reset disables the voltage reference by clearing bit, CVREN (CVRCON<7>). This Reset also disconnects the reference from the RA2 pin by clearing bit, CVROE (CVRCON<6>) and selects the high-voltage range by clearing bit, CVRR (CVRCON<5>). The CVR value select bits are also cleared. 21.5 Connection Considerations The voltage reference module operates independently of the comparator module. The output of the reference generator may be connected to the RA2 pin if the CVROE bit is set. Enabling the voltage reference output onto RA2 when it is configured as a digital input will increase current consumption. Connecting RA2 as a digital output with CVRSS enabled will also increase current consumption. The RA2 pin can be used as a simple D/A output with limited drive capability. Due to the limited current drive capability, a buffer must be used on the voltage reference output for external connections to VREF. Figure 21-2 shows an example buffering technique. 16-to-1 MUX CVR<3:0> 8R R CVREN CVRSS = 0 VDD VREF+ CVRSS = 1 8R CVRSS = 0 VREF- CVRSS = 1 R R R R R R 16 Steps CVRR CVREF© 2008 Microchip Technology Inc. DS39631E-page 241 PIC18F2420/2520/4420/4520 FIGURE 21-2: COMPARATOR VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE TABLE 21-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 51 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 51 TRISA TRISA7(1) TRISA6(1) PORTA Data Direction Register 52 Legend: Shaded cells are not used with the comparator voltage reference. Note 1: PORTA pins are enabled based on oscillator configuration. CVREF Output + – CVREF Module Voltage Reference Output Impedance R(1) RA2 Note 1: R is dependent upon the comparator voltage reference configuration bits, CVRCON<3:0> and CVRCON<5>. PIC18FXXXXPIC18F2420/2520/4420/4520 DS39631E-page 242 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. Advance Information DS39631E-page 243 PIC18F2420/2520/4420/4520 22.0 HIGH/LOW-VOLTAGE DETECT (HLVD) PIC18F2420/2520/4420/4520 devices have a High/Low-Voltage Detect module (HLVD). This is a programmable circuit that allows the user to specify both a device voltage trip point and the direction of change from that point. If the device experiences an excursion past the trip point in that direction, an interrupt flag is set. If the interrupt is enabled, the program execution will branch to the interrupt vector address and the software can then respond to the interrupt. The High/Low-Voltage Detect Control register (Register 22-1) completely controls the operation of the HLVD module. This allows the circuitry to be “turned off” by the user under software control, which minimizes the current consumption for the device. The block diagram for the HLVD module is shown in Figure 22-1. REGISTER 22-1: HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER R/W-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1 VDIRMAG — IRVST HLVDEN HLVDL3(1) HLVDL2(1) HLVDL1(1) HLVDL0(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 VDIRMAG: Voltage Direction Magnitude Select bit 1 = Event occurs when voltage equals or exceeds trip point (HLVDL<3:0>) 0 = Event occurs when voltage equals or falls below trip point (HLVDL<3:0>) bit 6 Unimplemented: Read as ‘0’ bit 5 IRVST: Internal Reference Voltage Stable Flag bit 1 = Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range 0 = Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage range and the HLVD interrupt should not be enabled bit 4 HLVDEN: High/Low-Voltage Detect Power Enable bit 1 = HLVD enabled 0 = HLVD disabled bit 3-0 HLVDL<3:0>: Voltage Detection Limit bits(1) 1111 = External analog input is used (input comes from the HLVDIN pin) 1110 = Maximum setting . . . 0000 = Minimum setting Note 1: See Table 26-4 for specifications.PIC18F2420/2520/4420/4520 DS39631E-page 244 Advance Information © 2008 Microchip Technology Inc. The module is enabled by setting the HLVDEN bit. Each time that the HLVD module is enabled, the circuitry requires some time to stabilize. The IRVST bit is a read-only bit and is used to indicate when the circuit is stable. The module can only generate an interrupt after the circuit is stable and IRVST is set. The VDIRMAG bit determines the overall operation of the module. When VDIRMAG is cleared, the module monitors for drops in VDD below a predetermined set point. When the bit is set, the module monitors for rises in VDD above the set point. 22.1 Operation When the HLVD module is enabled, a comparator uses an internally generated reference voltage as the set point. The set point is compared with the trip point, where each node in the resistor divider represents a trip point voltage. The “trip point” voltage is the voltage level at which the device detects a high or low-voltage event, depending on the configuration of the module. When the supply voltage is equal to the trip point, the voltage tapped off of the resistor array is equal to the internal reference voltage generated by the voltage reference module. The comparator then generates an interrupt signal by setting the HLVDIF bit. The trip point voltage is software programmable to any one of 16 values. The trip point is selected by programming the HLVDL<3:0> bits (HLVDCON<3:0>). The HLVD module has an additional feature that allows the user to supply the trip voltage to the module from an external source. This mode is enabled when bits, HLVDL<3:0>, are set to ‘1111’. In this state, the comparator input is multiplexed from the external input pin, HLVDIN. This gives users flexibility because it allows them to configure the High/Low-Voltage Detect interrupt to occur at any voltage in the valid operating range. FIGURE 22-1: HLVD MODULE BLOCK DIAGRAM (WITH EXTERNAL INPUT) Set VDD 16-to-1 MUX HLVDEN HLVDCON HLVDIN HLVDL<3:0> Register HLVDIN VDD Externally Generated Trip Point HLVDIF HLVDEN BOREN Internal Voltage Reference VDIRMAG© 2008 Microchip Technology Inc. Advance Information DS39631E-page 245 PIC18F2420/2520/4420/4520 22.2 HLVD Setup The following steps are needed to set up the HLVD module: 1. Write the value to the HLVDL<3:0> bits that selects the desired HLVD trip point. 2. Set the VDIRMAG bit to detect high voltage (VDIRMAG = 1) or low voltage (VDIRMAG = 0). 3. Enable the HLVD module by setting the HLVDEN bit. 4. Clear the HLVD interrupt flag (PIR2<2>), which may have been set from a previous interrupt. 5. Enable the HLVD interrupt, if interrupts are desired, by setting the HLVDIE and GIE bits (PIE2<2> and INTCON<7>). An interrupt will not be generated until the IRVST bit is set. 22.3 Current Consumption When the module is enabled, the HLVD comparator and voltage divider are enabled and will consume static current. The total current consumption, when enabled, is specified in electrical specification parameter D022B. Depending on the application, the HLVD module does not need to be operating constantly. To decrease the current requirements, the HLVD circuitry may only need to be enabled for short periods where the voltage is checked. After doing the check, the HLVD module may be disabled. 22.4 HLVD Start-up Time The internal reference voltage of the HLVD module, specified in electrical specification parameter D420, may be used by other internal circuitry, such as the programmable Brown-out Reset. If the HLVD or other circuits using the voltage reference are disabled to lower the device’s current consumption, the reference voltage circuit will require time to become stable before a low or high-voltage condition can be reliably detected. This start-up time, TIRVST, is an interval that is independent of device clock speed. It is specified in electrical specification parameter 36. The HLVD interrupt flag is not enabled until TIRVST has expired and a stable reference voltage is reached. For this reason, brief excursions beyond the set point may not be detected during this interval (refer to Figure 22-2 or Figure 22-3). FIGURE 22-2: LOW-VOLTAGE DETECT OPERATION (VDIRMAG = 0) VLVD VDD HLVDIF VLVD VDD Enable HLVD TIRVST HLVDIF may not be set Enable HLVD HLVDIF HLVDIF Cleared in Software HLVDIF Cleared in Software HLVDIF cleared in software, CASE 1: CASE 2: HLVDIF remains set since HLVD condition still exists TIRVST Internal Reference is Stable Internal Reference is Stable IRVST IRVSTPIC18F2420/2520/4420/4520 DS39631E-page 246 Advance Information © 2008 Microchip Technology Inc. FIGURE 22-3: HIGH-VOLTAGE DETECT OPERATION (VDIRMAG = 1) 22.5 Applications In many applications, the ability to detect a drop below, or rise above, a particular threshold is desirable. For example, the HLVD module could be periodically enabled to detect Universal Serial Bus (USB) attach or detach. This assumes the device is powered by a lower voltage source than the USB when detached. An attach would indicate a high-voltage detect from, for example, 3.3V to 5V (the voltage on USB) and vice versa for a detach. This feature could save a design a few extra components and an attach signal (input pin). For general battery applications, Figure 22-4 shows a possible voltage curve. Over time, the device voltage decreases. When the device voltage reaches voltage, VA, the HLVD logic generates an interrupt at time, TA. The interrupt could cause the execution of an ISR, which would allow the application to perform “housekeeping tasks” and perform a controlled shutdown before the device voltage exits the valid operating range at TB. The HLVD, thus, would give the application a time window, represented by the difference between TA and TB, to safely exit. FIGURE 22-4: TYPICAL LOW-VOLTAGE DETECT APPLICATION VLVD VDD HLVDIF VLVD VDD Enable HLVD TIRVST HLVDIF may not be set Enable HLVD HLVDIF HLVDIF Cleared in Software HLVDIF Cleared in Software HLVDIF cleared in software, CASE 1: CASE 2: HLVDIF remains set since HLVD condition still exists TIRVST IRVST Internal Reference is Stable Internal Reference is Stable IRVST Time Voltage VA VB TA TB VA = HLVD trip point VB = Minimum valid device operating voltage Legend:© 2008 Microchip Technology Inc. Advance Information DS39631E-page 247 PIC18F2420/2520/4420/4520 22.6 Operation During Sleep When enabled, the HLVD circuitry continues to operate during Sleep. If the device voltage crosses the trip point, the HLVDIF bit will be set and the device will wake-up from Sleep. Device execution will continue from the interrupt vector address if interrupts have been globally enabled. 22.7 Effects of a Reset A device Reset forces all registers to their Reset state. This forces the HLVD module to be turned off. TABLE 22-1: REGISTERS ASSOCIATED WITH HIGH/LOW-VOLTAGE DETECT MODULE Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page HLVDCON VDIRMAG — IRVST HLVDEN HLVDL3 HLVDL2 HLVDL1 HLVDL0 50 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 49 PIR2 OSCFIF CMIF — EEIF BCLIF HLVDIF TMR3IF CCP2IF 52 PIE2 OCSFIE CMIE — EEIE BCLIE HLVDIE TMR3IE CCP2IE 52 IPR2 OSCFIP CMIP — EEIP BCLIP HLVDIP TMR3IP CCP2IP 52 Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the HLVD module.PIC18F2420/2520/4420/4520 DS39631E-page 248 Advance Information © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 249 PIC18F2420/2520/4420/4520 23.0 SPECIAL FEATURES OF THE CPU PIC18F2420/2520/4420/4520 devices include several features intended to maximize reliability and minimize cost through elimination of external components. These are: • Oscillator Selection • Resets: - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) • Interrupts • Watchdog Timer (WDT) • Fail-Safe Clock Monitor • Two-Speed Start-up • Code Protection • ID Locations • In-Circuit Serial Programming The oscillator can be configured for the application depending on frequency, power, accuracy and cost. All of the options are discussed in detail in Section 2.0 “Oscillator Configurations”. A complete discussion of device Resets and interrupts is available in previous sections of this data sheet. In addition to their Power-up and Oscillator Start-up Timers provided for Resets, PIC18F2420/2520/4420/ 4520 devices have a Watchdog Timer, which is either permanently enabled via the Configuration bits or software controlled (if configured as disabled). The inclusion of an internal RC oscillator also provides the additional benefits of a Fail-Safe Clock Monitor (FSCM) and Two-Speed Start-up. FSCM provides for background monitoring of the peripheral clock and automatic switchover in the event of its failure. TwoSpeed Start-up enables code to be executed almost immediately on start-up, while the primary clock source completes its start-up delays. All of these features are enabled and configured by setting the appropriate Configuration register bits. 23.1 Configuration Bits The Configuration bits can be programmed (read as ‘0’) or left unprogrammed (read as ‘1’) to select various device configurations. These bits are mapped starting at program memory location, 300000h. The user will note that address 300000h is beyond the user program memory space. In fact, it belongs to the configuration memory space (300000h-3FFFFFh), which can only be accessed using table reads and table writes. Programming the Configuration registers is done in a manner similar to programming the Flash memory. The WR bit in the EECON1 register starts a self-timed write to the Configuration register. In normal operation mode, a TBLWT instruction with the TBLPTR pointing to the Configuration register sets up the address and the data for the Configuration register write. Setting the WR bit starts a long write to the Configuration register. The Configuration registers are written a byte at a time. To write or erase a configuration cell, a TBLWT instruction can write a ‘1’ or a ‘0’ into the cell. For additional details on Flash programming, refer to Section 6.5 “Writing to Flash Program Memory”. TABLE 23-1: CONFIGURATION BITS AND DEVICE IDs File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Default/ Unprogrammed Value 300001h CONFIG1H IESO FCMEN — — FOSC3 FOSC2 FOSC1 FOSC0 00-- 0111 300002h CONFIG2L — — — BORV1 BORV0 BOREN1 BOREN0 PWRTEN ---1 1111 300003h CONFIG2H — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN ---1 1111 300005h CONFIG3H MCLRE — — — — LPT1OSC PBADEN CCP2MX 1--- -011 300006h CONFIG4L DEBUG XINST — — — LVP — STVREN 10-- -1-1 300008h CONFIG5L — — — — CP3(1) CP2(1) CP1 CP0 ---- 1111 300009h CONFIG5H CPD CPB — — — — — — 11-- ---- 30000Ah CONFIG6L — — — — WRT3(1) WRT2(1) WRT1 WRT0 ---- 1111 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 111- ---- 30000Ch CONFIG7L — — — — EBTR3(1) EBTR2(1) EBTR1 EBTR0 ---- 1111 30000Dh CONFIG7H — EBTRB — — — — — — -1-- ---- 3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 xxxx xxxx(2) 3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 xxxx xxxx(2) Legend: x = unknown, u = unchanged, — = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as ‘0’. Note 1: Unimplemented in PIC18F2420/4420 devices; maintain this bit set. 2: See Register 23-12 for DEVID1 values. DEVID registers are read-only and cannot be programmed by the user.PIC18F2420/2520/4420/4520 DS39631E-page 250 © 2008 Microchip Technology Inc. REGISTER 23-1: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h) R/P-0 R/P-0 U-0 U-0 R/P-0 R/P-1 R/P-1 R/P-1 IESO FCMEN — — FOSC3 FOSC2 FOSC1 FOSC0 bit 7 bit 0 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7 IESO: Internal/External Oscillator Switchover bit 1 = Oscillator Switchover mode enabled 0 = Oscillator Switchover mode disabled bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit 1 = Fail-Safe Clock Monitor enabled 0 = Fail-Safe Clock Monitor disabled bit 5-4 Unimplemented: Read as ‘0’ bit 3-0 FOSC<3:0>: Oscillator Selection bits 11xx = External RC oscillator, CLKO function on RA6 101x = External RC oscillator, CLKO function on RA6 1001 = Internal oscillator block, CLKO function on RA6; port function on RA7 1000 = Internal oscillator block, port function on RA6 and RA7 0111 = External RC oscillator, port function on RA6 0110 = HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1) 0101 = EC oscillator, port function on RA6 0100 = EC oscillator, CLKO function on RA6 0011 = External RC oscillator, CLKO function on RA6 0010 = HS oscillator 0001 = XT oscillator 0000 = LP oscillator© 2008 Microchip Technology Inc. DS39631E-page 251 PIC18F2420/2520/4420/4520 REGISTER 23-2: CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h) U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 — — — BORV1(1) BORV0(1) BOREN1(2) BOREN0(2) PWRTEN(2) bit 7 bit 0 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-5 Unimplemented: Read as ‘0’ bit 4-3 BORV<1:0>: Brown-out Reset Voltage bits(1) 11 = Minimum setting . . . 00 = Maximum setting bit 2-1 BOREN<1:0>: Brown-out Reset Enable bits(2) 11 = Brown-out Reset enabled in hardware only (SBOREN is disabled) 10 = Brown-out Reset enabled in hardware only and disabled in Sleep mode (SBOREN is disabled) 01 = Brown-out Reset enabled and controlled by software (SBOREN is enabled) 00 = Brown-out Reset disabled in hardware and software bit 0 PWRTEN: Power-up Timer Enable bit(2) 1 = PWRT disabled 0 = PWRT enabled Note 1: See Section 26.1 “DC Characteristics: Supply Voltage” for specifications. 2: The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently controlled.PIC18F2420/2520/4420/4520 DS39631E-page 252 © 2008 Microchip Technology Inc. REGISTER 23-3: CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h) U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN bit 7 bit 0 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-5 Unimplemented: Read as ‘0’ bit 4-1 WDTPS<3:0>: Watchdog Timer Postscale Select bits 1111 = 1:32,768 1110 = 1:16,384 1101 = 1:8,192 1100 = 1:4,096 1011 = 1:2,048 1010 = 1:1,024 1001 = 1:512 1000 = 1:256 0111 = 1:128 0110 = 1:64 0101 = 1:32 0100 = 1:16 0011 = 1:8 0010 = 1:4 0001 = 1:2 0000 = 1:1 bit 0 WDTEN: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled (control is placed on the SWDTEN bit)© 2008 Microchip Technology Inc. DS39631E-page 253 PIC18F2420/2520/4420/4520 REGISTER 23-4: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h) R/P-1 U-0 U-0 U-0 U-0 R/P-0 R/P-1 R/P-1 MCLRE — — — — LPT1OSC PBADEN CCP2MX bit 7 bit 0 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7 MCLRE: MCLR Pin Enable bit 1 = MCLR pin enabled; RE3 input pin disabled 0 = RE3 input pin enabled; MCLR disabled bit 6-3 Unimplemented: Read as ‘0’ bit 2 LPT1OSC: Low-Power Timer1 Oscillator Enable bit 1 = Timer1 configured for low-power operation 0 = Timer1 configured for higher power operation bit 1 PBADEN: PORTB A/D Enable bit (Affects ADCON1 Reset state. ADCON1 controls PORTB<4:0> pin configuration.) 1 = PORTB<4:0> pins are configured as analog input channels on Reset 0 = PORTB<4:0> pins are configured as digital I/O on Reset bit 0 CCP2MX: CCP2 MUX bit 1 = CCP2 input/output is multiplexed with RC1 0 = CCP2 input/output is multiplexed with RB3 REGISTER 23-5: CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h) R/P-1 R/P-0 U-0 U-0 U-0 R/P-1 U-0 R/P-1 DEBUG XINST — — — LVP — STVREN bit 7 bit 0 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7 DEBUG: Background Debugger Enable bit 1 = Background debugger disabled, RB6 and RB7 configured as general purpose I/O pins 0 = Background debugger enabled, RB6 and RB7 are dedicated to In-Circuit Debug bit 6 XINST: Extended Instruction Set Enable bit 1 = Instruction set extension and Indexed Addressing mode enabled 0 = Instruction set extension and Indexed Addressing mode disabled (Legacy mode) bit 5-3 Unimplemented: Read as ‘0’ bit 2 LVP: Single-Supply ICSP™ Enable bit 1 = Single-Supply ICSP enabled 0 = Single-Supply ICSP disabled bit 1 Unimplemented: Read as ‘0’ bit 0 STVREN: Stack Full/Underflow Reset Enable bit 1 = Stack full/underflow will cause Reset 0 = Stack full/underflow will not cause ResetPIC18F2420/2520/4420/4520 DS39631E-page 254 © 2008 Microchip Technology Inc. REGISTER 23-6: CONFIG5L: CONFIGURATION REGISTER 5 LOW (BYTE ADDRESS 300008h) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — CP3(1) CP2(1) CP1 CP0 bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-4 Unimplemented: Read as ‘0’ bit 3 CP3: Code Protection bit(1) 1 = Block 3 (006000-007FFFh) not code-protected 0 = Block 3 (006000-007FFFh) code-protected bit 2 CP2: Code Protection bit(1) 1 = Block 2 (004000-005FFFh) not code-protected 0 = Block 2 (004000-005FFFh) code-protected bit 1 CP1: Code Protection bit 1 = Block 1 (002000-003FFFh) not code-protected 0 = Block 1 (002000-003FFFh) code-protected bit 0 CP0: Code Protection bit 1 = Block 0 (000800-001FFFh) not code-protected 0 = Block 0 (000800-001FFFh) code-protected Note 1: Unimplemented in PIC18F2420/4420 devices; maintain this bit set. REGISTER 23-7: CONFIG5H: CONFIGURATION REGISTER 5 HIGH (BYTE ADDRESS 300009h) R/C-1 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 CPD CPB — — — — — — bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7 CPD: Data EEPROM Code Protection bit 1 = Data EEPROM not code-protected 0 = Data EEPROM code-protected bit 6 CPB: Boot Block Code Protection bit 1 = Boot block (000000-0007FFh) not code-protected 0 = Boot block (000000-0007FFh) code-protected bit 5-0 Unimplemented: Read as ‘0’© 2008 Microchip Technology Inc. DS39631E-page 255 PIC18F2420/2520/4420/4520 REGISTER 23-8: CONFIG6L: CONFIGURATION REGISTER 6 LOW (BYTE ADDRESS 30000Ah) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — WRT3(1) WRT2(1) WRT1 WRT0 bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-4 Unimplemented: Read as ‘0’ bit 3 WRT3: Write Protection bit(1) 1 = Block 3 (006000-007FFFh) not write-protected 0 = Block 3 (006000-007FFFh) write-protected bit 2 WRT2: Write Protection bit(1) 1 = Block 2 (004000-005FFFh) not write-protected 0 = Block 2 (004000-005FFFh) write-protected bit 1 WRT1: Write Protection bit 1 = Block 1 (002000-003FFFh) not write-protected 0 = Block 1 (002000-003FFFh) write-protected bit 0 WRT0: Write Protection bit 1 = Block 0 (000800-001FFFh) not write-protected 0 = Block 0 (000800-001FFFh) write-protected Note 1: Unimplemented in PIC18F2420/4420 devices; maintain this bit set. REGISTER 23-9: CONFIG6H: CONFIGURATION REGISTER 6 HIGH (BYTE ADDRESS 30000Bh) R/C-1 R/C-1 R/C-1 U-0 U-0 U-0 U-0 U-0 WRTD WRTB WRTC(1) — — — — — bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7 WRTD: Data EEPROM Write Protection bit 1 = Data EEPROM not write-protected 0 = Data EEPROM write-protected bit 6 WRTB: Boot Block Write Protection bit 1 = Boot block (000000-0007FFh) not write-protected 0 = Boot block (000000-0007FFh) write-protected bit 5 WRTC: Configuration Register Write Protection bit(1) 1 = Configuration registers (300000-3000FFh) not write-protected 0 = Configuration registers (300000-3000FFh) write-protected bit 4-0 Unimplemented: Read as ‘0’ Note 1: This bit is read-only in normal execution mode; it can be written only in Program mode.PIC18F2420/2520/4420/4520 DS39631E-page 256 © 2008 Microchip Technology Inc. REGISTER 23-10: CONFIG7L: CONFIGURATION REGISTER 7 LOW (BYTE ADDRESS 30000Ch) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — EBTR3(1) EBTR2(1) EBTR1 EBTR0 bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-4 Unimplemented: Read as ‘0’ bit 3 EBTR3: Table Read Protection bit(1) 1 = Block 3 (006000-007FFFh) not protected from table reads executed in other blocks 0 = Block 3 (006000-007FFFh) protected from table reads executed in other blocks bit 2 EBTR2: Table Read Protection bit(1) 1 = Block 2 (004000-005FFFh) not protected from table reads executed in other blocks 0 = Block 2 (004000-005FFFh) protected from table reads executed in other blocks bit 1 EBTR1: Table Read Protection bit 1 = Block 1 (002000-003FFFh) not protected from table reads executed in other blocks 0 = Block 1 (002000-003FFFh) protected from table reads executed in other blocks bit 0 EBTR0: Table Read Protection bit 1 = Block 0 (000800-001FFFh) not protected from table reads executed in other blocks 0 = Block 0 (000800-001FFFh) protected from table reads executed in other blocks Note 1: Unimplemented in PIC18F2420/4420 devices; maintain this bit set. REGISTER 23-11: CONFIG7H: CONFIGURATION REGISTER 7 HIGH (BYTE ADDRESS 30000Dh) U-0 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 — EBTRB — — — — — — bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7 Unimplemented: Read as ‘0’ bit 6 EBTRB: Boot Block Table Read Protection bit 1 = Boot block (000000-0007FFh) not protected from table reads executed in other blocks 0 = Boot block (000000-0007FFh) protected from table reads executed in other blocks bit 5-0 Unimplemented: Read as ‘0’© 2008 Microchip Technology Inc. DS39631E-page 257 PIC18F2420/2520/4420/4520 REGISTER 23-12: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F2420/2520/4420/4520 R R R RR R R R DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 bit 7 bit 0 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-5 DEV<2:0>: Device ID bits 110 = PIC18F4420 100 = PIC18F4520 010 = PIC18F2420 000 = PIC18F2520 bit 4-0 REV<4:0>: Revision ID bits These bits are used to indicate the device revision. REGISTER 23-13: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F2420/2520/4420/4520 R R R RR R R R DEV10(1) DEV9(1) DEV8(1) DEV7(1) DEV6(1) DEV5(1) DEV4(1) DEV3(1) bit 7 bit 0 Legend: R = Read-only bit P = Programmable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed u = Unchanged from programmed state bit 7-0 DEV<10:3>: Device ID bits(1) These bits are used with the DEV<2:0> bits in Device ID Register 1 to identify the part number. 0001 0001 = PIC18F2420/2520 devices 0001 0000 = PIC18F4420/4520 devices Note 1: These values for DEV<10:3> may be shared with other devices. The specific device is always identified by using the entire DEV<10:0> bit sequence.PIC18F2420/2520/4420/4520 DS39631E-page 258 © 2008 Microchip Technology Inc. 23.2 Watchdog Timer (WDT) For PIC18F2420/2520/4420/4520 devices, the WDT is driven by the INTRC source. When the WDT is enabled, the clock source is also enabled. The nominal WDT period is 4 ms and has the same stability as the INTRC oscillator. The 4 ms period of the WDT is multiplied by a 16-bit postscaler. Any output of the WDT postscaler is selected by a multiplexer, controlled by bits in Configuration Register 2H. Available periods range from 4 ms to 131.072 seconds (2.18 minutes). The WDT and postscaler are cleared when any of the following events occur: a SLEEP or CLRWDT instruction is executed, the IRCF bits (OSCCON<6:4>) are changed or a clock failure has occurred. 23.2.1 CONTROL REGISTER Register 23-14 shows the WDTCON register. This is a readable and writable register which contains a control bit that allows software to override the WDT enable Configuration bit, but only if the Configuration bit has disabled the WDT. FIGURE 23-1: WDT BLOCK DIAGRAM Note 1: The CLRWDT and SLEEP instructions clear the WDT and postscaler counts when executed. 2: Changing the setting of the IRCF bits (OSCCON<6:4>) clears the WDT and postscaler counts. 3: When a CLRWDT instruction is executed, the postscaler count will be cleared. INTRC Source WDT Wake-up from Reset WDT Counter Programmable Postscaler 1:1 to 1:32,768 Enable WDT WDTPS<3:0> SWDTEN WDTEN CLRWDT 4 Power-Managed Reset All Device Resets Sleep ÷128 Change on IRCF bits Modes© 2008 Microchip Technology Inc. DS39631E-page 259 PIC18F2420/2520/4420/4520 TABLE 23-2: SUMMARY OF WATCHDOG TIMER REGISTERS REGISTER 23-14: WDTCON: WATCHDOG TIMER CONTROL REGISTER U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 — — — — — — — SWDTEN(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-1 Unimplemented: Read as ‘0’ bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit(1) 1 = Watchdog Timer is on 0 = Watchdog Timer is off Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RCON IPEN SBOREN(1) — RI TO PD POR BOR 48 WDTCON — — — — — — — SWDTEN(2) 50 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer. Note 1: The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, it is disabled and reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”. 2: This bit has no effect if the Configuration bit, WDTEN, is enabled.PIC18F2420/2520/4420/4520 DS39631E-page 260 © 2008 Microchip Technology Inc. 23.3 Two-Speed Start-up The Two-Speed Start-up feature helps to minimize the latency period from oscillator start-up to code execution by allowing the microcontroller to use the INTOSC oscillator as a clock source until the primary clock source is available. It is enabled by setting the IESO Configuration bit. Two-Speed Start-up should be enabled only if the primary oscillator mode is LP, XT, HS or HSPLL (Crystal-Based modes). Other sources do not require an OST start-up delay; for these, Two-Speed Start-up should be disabled. When enabled, Resets and wake-ups from Sleep mode cause the device to configure itself to run from the internal oscillator block as the clock source, following the time-out of the Power-up Timer after a Power-on Reset is enabled. This allows almost immediate code execution while the primary oscillator starts and the OST is running. Once the OST times out, the device automatically switches to PRI_RUN mode. To use a higher clock speed on wake-up, the INTOSC or postscaler clock sources can be selected to provide a higher clock speed by setting bits, IRCF<2:0>, immediately after Reset. For wake-ups from Sleep, the INTOSC or postscaler clock sources can be selected by setting the IRCF<2:0> bits prior to entering Sleep mode. In all other power-managed modes, Two-Speed Startup is not used. The device will be clocked by the currently selected clock source until the primary clock source becomes available. The setting of the IESO bit is ignored. 23.3.1 SPECIAL CONSIDERATIONS FOR USING TWO-SPEED START-UP While using the INTOSC oscillator in Two-Speed Startup, the device still obeys the normal command sequences for entering power-managed modes, including multiple SLEEP instructions (refer to Section 3.1.4 “Multiple Sleep Commands”). In practice, this means that user code can change the SCS<1:0> bit settings or issue SLEEP instructions before the OST times out. This would allow an application to briefly wake-up, perform routine “housekeeping” tasks and return to Sleep before the device starts to operate from the primary oscillator. User code can also check if the primary clock source is currently providing the device clocking by checking the status of the OSTS bit (OSCCON<3>). If the bit is set, the primary oscillator is providing the clock. Otherwise, the internal oscillator block is providing the clock during wake-up from Reset or Sleep mode. FIGURE 23-2: TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL) Q1 Q3 Q4 OSC1 Peripheral Program PC PC + 2 INTOSC PLL Clock Q1 PC + 6 Q2 Output Q3 Q4 Q1 CPU Clock PC + 4 Clock Counter Q2 Q2 Q3 Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2: Clock transition typically occurs within 2-4 TOSC. Wake from Interrupt Event TPLL(1) 1 2 n-1 n Clock OSTS bit Set Transition(2) Multiplexer TOST(1)© 2008 Microchip Technology Inc. DS39631E-page 261 PIC18F2420/2520/4420/4520 23.4 Fail-Safe Clock Monitor The Fail-Safe Clock Monitor (FSCM) allows the microcontroller to continue operation in the event of an external oscillator failure by automatically switching the device clock to the internal oscillator block. The FSCM function is enabled by setting the FCMEN Configuration bit. When FSCM is enabled, the INTRC oscillator runs at all times to monitor clocks to peripherals and provide a backup clock in the event of a clock failure. Clock monitoring (shown in Figure 23-3) is accomplished by creating a sample clock signal, which is the INTRC output divided by 64. This allows ample time between FSCM sample clocks for a peripheral clock edge to occur. The peripheral device clock and the sample clock are presented as inputs to the Clock Monitor latch (CM). The CM is set on the falling edge of the device clock source, but cleared on the rising edge of the sample clock. FIGURE 23-3: FSCM BLOCK DIAGRAM Clock failure is tested for on the falling edge of the sample clock. If a sample clock falling edge occurs while CM is still set, a clock failure has been detected (Figure 23-4). This causes the following: • the FSCM generates an oscillator fail interrupt by setting bit, OSCFIF (PIR2<7>); • the device clock source is switched to the internal oscillator block (OSCCON is not updated to show the current clock source – this is the fail-safe condition) and • the WDT is reset. During switchover, the postscaler frequency from the internal oscillator block may not be sufficiently stable for timing sensitive applications. In these cases, it may be desirable to select another clock configuration and enter an alternate power-managed mode. This can be done to attempt a partial recovery or execute a controlled shutdown. See Section 3.1.4 “Multiple Sleep Commands” and Section 23.3.1 “Special Considerations for Using Two-Speed Start-up” for more details. To use a higher clock speed on wake-up, the INTOSC or postscaler clock sources can be selected to provide a higher clock speed by setting bits, IRCF<2:0>, immediately after Reset. For wake-ups from Sleep, the INTOSC or postscaler clock sources can be selected by setting the IRCF<2:0> bits prior to entering Sleep mode. The FSCM will detect failures of the primary or secondary clock sources only. If the internal oscillator block fails, no failure would be detected, nor would any action be possible. 23.4.1 FSCM AND THE WATCHDOG TIMER Both the FSCM and the WDT are clocked by the INTRC oscillator. Since the WDT operates with a separate divider and counter, disabling the WDT has no effect on the operation of the INTRC oscillator when the FSCM is enabled. As already noted, the clock source is switched to the INTOSC clock when a clock failure is detected. Depending on the frequency selected by the IRCF<2:0> bits, this may mean a substantial change in the speed of code execution. If the WDT is enabled with a small prescale value, a decrease in clock speed allows a WDT time-out to occur and a subsequent device Reset. For this reason, fail-safe clock events also reset the WDT and postscaler, allowing it to start timing from when execution speed was changed and decreasing the likelihood of an erroneous time-out. 23.4.2 EXITING FAIL-SAFE OPERATION The fail-safe condition is terminated by either a device Reset or by entering a power-managed mode. On Reset, the controller starts the primary clock source specified in Configuration Register 1H (with any required start-up delays that are required for the oscillator mode, such as the OST or PLL timer). The INTOSC multiplexer provides the device clock until the primary clock source becomes ready (similar to a TwoSpeed Start-up). The clock source is then switched to the primary clock (indicated by the OSTS bit in the OSCCON register becoming set). The Fail-Safe Clock Monitor then resumes monitoring the peripheral clock. The primary clock source may never become ready during start-up. In this case, operation is clocked by the INTOSC multiplexer. The OSCCON register will remain in its Reset state until a power-managed mode is entered. Peripheral INTRC ÷ 64 S C Q (32 μs) 488 Hz (2.048 ms) Clock Monitor Latch (CM) (edge-triggered) Clock Failure Detected Source Clock QPIC18F2420/2520/4420/4520 DS39631E-page 262 © 2008 Microchip Technology Inc. FIGURE 23-4: FSCM TIMING DIAGRAM 23.4.3 FSCM INTERRUPTS IN POWER-MANAGED MODES By entering a power-managed mode, the clock multiplexer selects the clock source selected by the OSCCON register. Fail-Safe Clock Monitoring of the powermanaged clock source resumes in the power-managed mode. If an oscillator failure occurs during power-managed operation, the subsequent events depend on whether or not the oscillator failure interrupt is enabled. If enabled (OSCFIF = 1), code execution will be clocked by the INTOSC multiplexer. An automatic transition back to the failed clock source will not occur. If the interrupt is disabled, subsequent interrupts while in Idle mode will cause the CPU to begin executing instructions while being clocked by the INTOSC source. 23.4.4 POR OR WAKE FROM SLEEP The FSCM is designed to detect oscillator failure at any point after the device has exited Power-on Reset (POR) or low-power Sleep mode. When the primary device clock is EC, RC or INTRC modes, monitoring can begin immediately following these events. For oscillator modes involving a crystal or resonator (HS, HSPLL, LP or XT), the situation is somewhat different. Since the oscillator may require a start-up time considerably longer than the FCSM sample clock time, a false clock failure may be detected. To prevent this, the internal oscillator block is automatically configured as the device clock and functions until the primary clock is stable (the OST and PLL timers have timed out). This is identical to Two-Speed Start-up mode. Once the primary clock is stable, the INTRC returns to its role as the FSCM source. As noted in Section 23.3.1 “Special Considerations for Using Two-Speed Start-up”, it is also possible to select another clock configuration and enter an alternate power-managed mode while waiting for the primary clock to become stable. When the new powermanaged mode is selected, the primary clock is disabled. OSCFIF CM Output Device Clock Output Sample Clock Failure Detected Oscillator Failure Note: The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in this example have been chosen for clarity. (Q) CM Test CM Test CM Test Note: The same logic that prevents false oscillator failure interrupts on POR, or wake from Sleep, will also prevent the detection of the oscillator’s failure to start at all following these events. This can be avoided by monitoring the OSTS bit and using a timing routine to determine if the oscillator is taking too long to start. Even so, no oscillator failure interrupt will be flagged. © 2008 Microchip Technology Inc. DS39631E-page 263 PIC18F2420/2520/4420/4520 23.5 Program Verification and Code Protection The overall structure of the code protection on the PIC18 Flash devices differs significantly from other PIC® devices. The user program memory is divided into five blocks. One of these is a boot block of 2 Kbytes. The remainder of the memory is divided into four blocks on binary boundaries. Each of the five blocks has three code protection bits associated with them. They are: • Code-Protect bit (CPn) • Write-Protect bit (WRTn) • External Block Table Read bit (EBTRn) Figure 23-5 shows the program memory organization for 16 and 32-Kbyte devices and the specific code protection bit associated with each block. The actual locations of the bits are summarized in Table 23-3. FIGURE 23-5: CODE-PROTECTED PROGRAM MEMORY FOR PIC18F2420/2520/4420/4520 TABLE 23-3: SUMMARY OF CODE PROTECTION REGISTERS File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 300008h CONFIG5L — — — — CP3(1) CP2(1) CP1 CP0 300009h CONFIG5H CPD CPB — — — — — — 30000Ah CONFIG6L — — — — WRT3(1) WRT2(1) WRT1 WRT0 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 30000Ch CONFIG7L — — — — EBTR3(1) EBTR2(1) EBTR1 EBTR0 30000Dh CONFIG7H — EBTRB — — — — — — Legend: Shaded cells are unimplemented. Note 1: Unimplemented in PIC18F2420/4420 devices; maintain this bit set. MEMORY SIZE/DEVICE Block Code Protection 16 Kbytes Controlled By: (PIC18F2420/4420) 32 Kbytes (PIC18F2520/4520) Address Range Boot Block Boot Block 000000h 0007FFh CPB, WRTB, EBTRB Block 0 Block 0 000800h 001FFFh CP0, WRT0, EBTR0 Block 1 Block 1 002000h 003FFFh CP1, WRT1, EBTR1 Unimplemented Read ‘0’s Block 2 004000h 005FFFh CP2, WRT2, EBTR2 Block 3 006000h 007FFFh CP3, WRT3, EBTR3 Unimplemented Read ‘0’s 1FFFFFh (Unimplemented Memory Space)PIC18F2420/2520/4420/4520 DS39631E-page 264 © 2008 Microchip Technology Inc. 23.5.1 PROGRAM MEMORY CODE PROTECTION The program memory may be read to, or written from, any location using the table read and table write instructions. The Device ID may be read with table reads. The Configuration registers may be read and written with the table read and table write instructions. In normal execution mode, the CPn bits have no direct effect. CPn bits inhibit external reads and writes. A block of user memory may be protected from table writes if the WRTn Configuration bit is ‘0’. The EBTRn bits control table reads. For a block of user memory with the EBTRn bit set to ‘0’, a table read instruction that executes from within that block is allowed to read. A table read instruction that executes from a location outside of that block is not allowed to read and will result in reading ‘0’s. Figures 23-6 through 23-8 illustrate table write and table read protection. FIGURE 23-6: TABLE WRITE (WRTn) DISALLOWED Note: Code protection bits may only be written to a ‘0’ from a ‘1’ state. It is not possible to write a ‘1’ to a bit in the ‘0’ state. Code protection bits are only set to ‘1’ by a full chip erase or block erase function. The full chip erase and block erase functions can only be initiated via ICSP or an external programmer. 000000h 0007FFh 000800h 001FFFh 002000h 003FFFh 004000h 005FFFh 006000h 007FFFh WRTB, EBTRB = 11 WRT0, EBTR0 = 01 WRT1, EBTR1 = 11 WRT2, EBTR2 = 11 WRT3, EBTR3 = 11 TBLWT* TBLPTR = 0008FFh PC = 001FFEh PC = 005FFEh TBLWT* Register Values Program Memory Configuration Bit Settings Results: All table writes disabled to Blockn whenever WRTn = 0.© 2008 Microchip Technology Inc. DS39631E-page 265 PIC18F2420/2520/4420/4520 FIGURE 23-7: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED FIGURE 23-8: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED WRTB, EBTRB = 11 WRT0, EBTR0 = 10 WRT1, EBTR1 = 11 WRT2, EBTR2 = 11 WRT3, EBTR3 = 11 TBLRD* TBLPTR = 0008FFh PC = 003FFEh Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0. TABLAT register returns a value of ‘0’. Register Values Program Memory Configuration Bit Settings 000000h 0007FFh 000800h 001FFFh 002000h 003FFFh 004000h 005FFFh 006000h 007FFFh WRTB, EBTRB = 11 WRT0, EBTR0 = 10 WRT1, EBTR1 = 11 WRT2, EBTR2 = 11 WRT3, EBTR3 = 11 TBLRD* TBLPTR = 0008FFh PC = 001FFEh Register Values Program Memory Configuration Bit Settings Results: Table reads permitted within Blockn, even when EBTRBn = 0. TABLAT register returns the value of the data at the location TBLPTR. 000000h 0007FFh 000800h 001FFFh 002000h 003FFFh 004000h 005FFFh 006000h 007FFFhPIC18F2420/2520/4420/4520 DS39631E-page 266 © 2008 Microchip Technology Inc. 23.5.2 DATA EEPROM CODE PROTECTION The entire data EEPROM is protected from external reads and writes by two bits: CPD and WRTD. CPD inhibits external reads and writes of data EEPROM. WRTD inhibits internal and external writes to data EEPROM. The CPU can always read data EEPROM under normal operation, regardless of the protection bit settings. 23.5.3 CONFIGURATION REGISTER PROTECTION The Configuration registers can be write-protected. The WRTC bit controls protection of the Configuration registers. In normal execution mode, the WRTC bit is read-only. WRTC can only be written via ICSP or an external programmer. 23.6 ID Locations Eight memory locations (200000h-200007h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are both readable and writable during normal execution through the TBLRD and TBLWT instructions, or during program/verify. The ID locations can be read when the device is code-protected. 23.7 In-Circuit Serial Programming PIC18F2420/2520/4420/4520 devices can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed. 23.8 In-Circuit Debugger When the DEBUG Configuration bit is programmed to a ‘0’, the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB® IDE. When the microcontroller has this feature enabled, some resources are not available for general use. Table 23-4 shows which resources are required by the background debugger. TABLE 23-4: DEBUGGER RESOURCES To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to MCLR/VPP/RE3, VDD, VSS, RB7 and RB6. This will interface to the In-Circuit Debugger module available from Microchip or one of the third party development tool companies. 23.9 Single-Supply ICSP Programming The LVP Configuration bit enables Single-Supply ICSP Programming (formerly known as Low-Voltage ICSP Programming or LVP). When Single-Supply Programming is enabled, the microcontroller can be programmed without requiring high voltage being applied to the MCLR/VPP/RE3 pin, but the RB5/KBI1/PGM pin is then dedicated to controlling Program mode entry and is not available as a general purpose I/O pin. While programming, using Single-Supply Programming mode, VDD is applied to the MCLR/VPP/RE3 pin as in normal execution mode. To enter Programming mode, VDD is applied to the PGM pin. If Single-Supply ICSP Programming mode will not be used, the LVP bit can be cleared. RB5/KBI1/PGM then becomes available as the digital I/O pin, RB5. The LVP bit may be set or cleared only when using standard high-voltage programming (VIHH applied to the MCLR/ VPP/RE3 pin). Once LVP has been disabled, only the standard high-voltage programming is available and must be used to program the device. Memory that is not code-protected can be erased using either a block erase, or erased row by row, then written at any specified VDD. If code-protected memory is to be erased, a block erase is required. If a block erase is to be performed when using Low-Voltage Programming, the device must be supplied with VDD of 4.5V to 5.5V. I/O pins: RB6, RB7 Stack: 2 levels Program Memory: 512 bytes Data Memory: 10 bytes Note 1: High-voltage programming is always available, regardless of the state of the LVP bit or the PGM pin, by applying VIHH to the MCLR pin. 2: By default, Single-Supply ICSP is enabled in unprogrammed devices (as supplied from Microchip) and erased devices. 3: When Single-Supply Programming is enabled, the RB5 pin can no longer be used as a general purpose I/O pin. 4: When LVP is enabled, externally pull the PGM pin to VSS to allow normal program execution.© 2008 Microchip Technology Inc. DS39631E-page 267 PIC18F2420/2520/4420/4520 24.0 INSTRUCTION SET SUMMARY PIC18F2420/2520/4420/4520 devices incorporate the standard set of 75 PIC18 core instructions, as well as an extended set of 8 new instructions, for the optimization of code that is recursive or that utilizes a software stack. The extended set is discussed later in this section. 24.1 Standard Instruction Set The standard PIC18 instruction set adds many enhancements to the previous PIC® MCU instruction sets, while maintaining an easy migration from these PIC MCU instruction sets. Most instructions are a single program memory word (16 bits), but there are four instructions that require two program memory locations. Each single-word instruction is a 16-bit word divided into an opcode, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. The instruction set is highly orthogonal and is grouped into four basic categories: • Byte-oriented operations • Bit-oriented operations • Literal operations • Control operations The PIC18 instruction set summary in Table 24-2 lists byte-oriented, bit-oriented, literal and control operations. Table 24-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. The file register (specified by ‘f’) 2. The destination of the result (specified by ‘d’) 3. The accessed memory (specified by ‘a’) The file register designator ‘f’ specifies which file register is to be used by the instruction. The destination designator ‘d’ specifies where the result of the operation is to be placed. If ‘d’ is zero, the result is placed in the WREG register. If ‘d’ is one, the result is placed in the file register specified in the instruction. All bit-oriented instructions have three operands: 1. The file register (specified by ‘f’) 2. The bit in the file register (specified by ‘b’) 3. The accessed memory (specified by ‘a’) The bit field designator ‘b’ selects the number of the bit affected by the operation, while the file register designator ‘f’ represents the number of the file in which the bit is located. The literal instructions may use some of the following operands: • A literal value to be loaded into a file register (specified by ‘k’) • The desired FSR register to load the literal value into (specified by ‘f’) • No operand required (specified by ‘—’) The control instructions may use some of the following operands: • A program memory address (specified by ‘n’) • The mode of the CALL or RETURN instructions (specified by ‘s’) • The mode of the table read and table write instructions (specified by ‘m’) • No operand required (specified by ‘—’) All instructions are a single word, except for four double-word instructions. These instructions were made double-word to contain the required information in 32 bits. In the second word, the 4 MSbs are ‘1’s. If this second word is executed as an instruction (by itself), it will execute as a NOP. All single-word instructions are executed in a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruction. In these cases, the execution takes two instruction cycles, with the additional instruction cycle(s) executed as a NOP. The double-word instructions execute in two instruction cycles. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 μs. If a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 μs. Two-word branch instructions (if true) would take 3 μs. Figure 24-1 shows the general formats that the instructions can have. All examples use the convention ‘nnh’ to represent a hexadecimal number. The Instruction Set Summary, shown in Table 24-2, lists the standard instructions recognized by the Microchip Assembler (MPASMTM). Section 24.1.1 “Standard Instruction Set” provides a description of each instruction.PIC18F2420/2520/4420/4520 DS39631E-page 268 © 2008 Microchip Technology Inc. TABLE 24-1: OPCODE FIELD DESCRIPTIONS Field Description a RAM access bit a = 0: RAM location in Access RAM (BSR register is ignored) a = 1: RAM bank is specified by BSR register bbb Bit address within an 8-bit file register (0 to 7). BSR Bank Select Register. Used to select the current RAM bank. C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative. d Destination select bit d = 0: store result in WREG d = 1: store result in file register f dest Destination: either the WREG register or the specified register file location. f 8-bit Register file address (00h to FFh) or 2-bit FSR designator (0h to 3h). fs 12-bit Register file address (000h to FFFh). This is the source address. fd 12-bit Register file address (000h to FFFh). This is the destination address. GIE Global Interrupt Enable bit. k Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value). label Label name. mm The mode of the TBLPTR register for the table read and table write instructions. Only used with table read and table write instructions: * No change to register (such as TBLPTR with table reads and writes) *+ Post-Increment register (such as TBLPTR with table reads and writes) *- Post-Decrement register (such as TBLPTR with table reads and writes) +* Pre-Increment register (such as TBLPTR with table reads and writes) n The relative address (2’s complement number) for relative branch instructions or the direct address for Call/Branch and Return instructions. PC Program Counter. PCL Program Counter Low Byte. PCH Program Counter High Byte. PCLATH Program Counter High Byte Latch. PCLATU Program Counter Upper Byte Latch. PD Power-down bit. PRODH Product of Multiply High Byte. PRODL Product of Multiply Low Byte. s Fast Call/Return mode select bit s = 0: do not update into/from shadow registers s = 1: certain registers loaded into/from shadow registers (Fast mode) TBLPTR 21-bit Table Pointer (points to a Program Memory location). TABLAT 8-bit Table Latch. TO Time-out bit. TOS Top-of-Stack. u Unused or unchanged. WDT Watchdog Timer. WREG Working register (accumulator). x Don’t care (‘0’ or ‘1’). The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. zs 7-bit offset value for indirect addressing of register files (source). zd 7-bit offset value for indirect addressing of register files (destination). { } Optional argument. [text] Indicates an indexed address. (text) The contents of text. [expr] Specifies bit n of the register indicated by the pointer expr. → Assigned to. < > Register bit field. ∈ In the set of. italics User-defined term (font is Courier New).© 2008 Microchip Technology Inc. DS39631E-page 269 PIC18F2420/2520/4420/4520 FIGURE 24-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 15 10 9 8 7 0 d = 0 for result destination to be WREG register OPCODE d a f (FILE #) d = 1 for result destination to be file register (f) a = 0 to force Access Bank Bit-oriented file register operations 15 12 11 9 8 7 0 OPCODE b (BIT #) a f (FILE #) b = 3-bit position of bit in file register (f) Literal operations 15 8 7 0 OPCODE k (literal) k = 8-bit immediate value Byte to Byte move operations (2-word) 15 12 11 0 OPCODE f (Source FILE #) CALL, GOTO and Branch operations 15 8 7 0 OPCODE n<7:0> (literal) n = 20-bit immediate value a = 1 for BSR to select bank f = 8-bit file register address a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address 15 12 11 0 1111 n<19:8> (literal) 15 12 11 0 1111 f (Destination FILE #) f = 12-bit file register address Control operations Example Instruction ADDWF MYREG, W, B MOVFF MYREG1, MYREG2 BSF MYREG, bit, B MOVLW 7Fh GOTO Label 15 8 7 0 OPCODE n<7:0> (literal) 15 12 11 0 1111 n<19:8> (literal) CALL MYFUNC 15 11 10 0 OPCODE n<10:0> (literal) S = Fast bit BRA MYFUNC 15 8 7 0 OPCODE n<7:0> (literal) BC MYFUNC SPIC18F2420/2520/4420/4520 DS39631E-page 270 © 2008 Microchip Technology Inc. TABLE 24-2: PIC18FXXXX INSTRUCTION SET Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb BYTE-ORIENTED OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB SUBWF SUBWFB SWAPF TSTFSZ XORWF f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a fs, fd f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a Add WREG and f Add WREG and Carry bit to f AND WREG with f Clear f Complement f Compare f with WREG, Skip = Compare f with WREG, Skip > Compare f with WREG, Skip < Decrement f Decrement f, Skip if 0 Decrement f, Skip if Not 0 Increment f Increment f, Skip if 0 Increment f, Skip if Not 0 Inclusive OR WREG with f Move f Move fs (source) to 1st word fd (destination) 2nd word Move WREG to f Multiply WREG with f Negate f Rotate Left f through Carry Rotate Left f (No Carry) Rotate Right f through Carry Rotate Right f (No Carry) Set f Subtract f from WREG with Borrow Subtract WREG from f Subtract WREG from f with Borrow Swap Nibbles in f Test f, Skip if 0 Exclusive OR WREG with f 1 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 (2 or 3) 1 0010 0010 0001 0110 0001 0110 0110 0110 0000 0010 0100 0010 0011 0100 0001 0101 1100 1111 0110 0000 0110 0011 0100 0011 0100 0110 0101 0101 0101 0011 0110 0001 01da 00da 01da 101a 11da 001a 010a 000a 01da 11da 11da 10da 11da 10da 00da 00da ffff ffff 111a 001a 110a 01da 01da 00da 00da 100a 01da 11da 10da 10da 011a 10da ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None None None C, DC, Z, OV, N C, Z, N Z, N C, Z, N Z, N None C, DC, Z, OV, N C, DC, Z, OV, N C, DC, Z, OV, N None None Z, N 1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1 1, 2 1, 2 1, 2 1, 2 4 1, 2 Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’. 2: If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if assigned. 3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction.© 2008 Microchip Technology Inc. DS39631E-page 271 PIC18F2420/2520/4420/4520 BIT-ORIENTED OPERATIONS BCF BSF BTFSC BTFSS BTG f, b, a f, b, a f, b, a f, b, a f, d, a Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set Bit Toggle f 1 1 1 (2 or 3) 1 (2 or 3) 1 1001 1000 1011 1010 0111 bbba bbba bbba bbba bbba ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff None None None None None 1, 2 1, 2 3, 4 3, 4 1, 2 CONTROL OPERATIONS BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL CLRWDT DAW GOTO NOP NOP POP PUSH RCALL RESET RETFIE RETLW RETURN SLEEP n n n n n n n n n n, s — — n — — — — n s k s — Branch if Carry Branch if Negative Branch if Not Carry Branch if Not Negative Branch if Not Overflow Branch if Not Zero Branch if Overflow Branch Unconditionally Branch if Zero Call Subroutine 1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to Address 1st word 2nd word No Operation No Operation Pop Top of Return Stack (TOS) Push Top of Return Stack (TOS) Relative Call Software Device Reset Return from Interrupt Enable Return with Literal in WREG Return from Subroutine Go into Standby mode 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 2 1 1 2 1 1 1 1 2 1 2 2 2 1 1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 0000 0000 0000 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 1100 0000 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 kkkk 0001 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s kkkk 001s 0011 None None None None None None None None None None TO, PD C None None None None None None All GIE/GIEH, PEIE/GIEL None None TO, PD 4 TABLE 24-2: PIC18FXXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’. 2: If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if assigned. 3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction.PIC18F2420/2520/4420/4520 DS39631E-page 272 © 2008 Microchip Technology Inc. LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR MOVLB MOVLW MULLW RETLW SUBLW XORLW k k k f, k k k k k k k Add Literal and WREG AND Literal with WREG Inclusive OR Literal with WREG Move Literal (12-bit)2nd word to FSR(f) 1st word Move Literal to BSR<3:0> Move Literal to WREG Multiply Literal with WREG Return with Literal in WREG Subtract WREG from Literal Exclusive OR Literal with WREG 1 1 1 2 1 1 1 2 1 1 0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk C, DC, Z, OV, N Z, N Z, N None None None None None C, DC, Z, OV, N Z, N DATA MEMORY ↔ PROGRAM MEMORY OPERATIONS TBLRD* TBLRD*+ TBLRD*- TBLRD+* TBLWT* TBLWT*+ TBLWT*- TBLWT+* Table Read Table Read with Post-Increment Table Read with Post-Decrement Table Read with Pre-Increment Table Write Table Write with Post-Increment Table Write with Post-Decrement Table Write with Pre-Increment 2 2 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 1001 1010 1011 1100 1101 1110 1111 None None None None None None None None TABLE 24-2: PIC18FXXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’. 2: If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if assigned. 3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction.© 2008 Microchip Technology Inc. DS39631E-page 273 PIC18F2420/2520/4420/4520 24.1.1 STANDARD INSTRUCTION SET ADDLW ADD Literal to W Syntax: ADDLW k Operands: 0 ≤ k ≤ 255 Operation: (W) + k → W Status Affected: N, OV, C, DC, Z Encoding: 0000 1111 kkkk kkkk Description: The contents of W are added to the 8-bit literal ‘k’ and the result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: ADDLW 15h Before Instruction W = 10h After Instruction W = 25h ADDWF ADD W to f Syntax: ADDWF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) + (f) → dest Status Affected: N, OV, C, DC, Z Encoding: 0010 01da ffff ffff Description: Add W to register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ADDWF REG, 0, 0 Before Instruction W = 17h REG = 0C2h After Instruction W = 0D9h REG = 0C2h Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).PIC18F2420/2520/4420/4520 DS39631E-page 274 © 2008 Microchip Technology Inc. ADDWFC ADD W and Carry bit to f Syntax: ADDWFC f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) + (f) + (C) → dest Status Affected: N,OV, C, DC, Z Encoding: 0010 00da ffff ffff Description: Add W, the Carry flag and data memory location ‘f’. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed in data memory location ‘f’. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ADDWFC REG, 0, 1 Before Instruction Carry bit = 1 REG = 02h W = 4Dh After Instruction Carry bit = 0 REG = 02h W = 50h ANDLW AND Literal with W Syntax: ANDLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .AND. k → W Status Affected: N, Z Encoding: 0000 1011 kkkk kkkk Description: The contents of W are ANDed with the 8-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: ANDLW 05Fh Before Instruction W = A3h After Instruction W = 03h© 2008 Microchip Technology Inc. DS39631E-page 275 PIC18F2420/2520/4420/4520 ANDWF AND W with f Syntax: ANDWF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .AND. (f) → dest Status Affected: N, Z Encoding: 0001 01da ffff ffff Description: The contents of W are ANDed with register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ANDWF REG, 0, 0 Before Instruction W = 17h REG = C2h After Instruction W = 02h REG = C2h BC Branch if Carry Syntax: BC n Operands: -128 ≤ n ≤ 127 Operation: if Carry bit is ‘1’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0010 nnnn nnnn Description: If the Carry bit is ‘1’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BC 5 Before Instruction PC = address (HERE) After Instruction If Carry = 1; PC = address (HERE + 12) If Carry = 0; PC = address (HERE + 2)PIC18F2420/2520/4420/4520 DS39631E-page 276 © 2008 Microchip Technology Inc. BCF Bit Clear f Syntax: BCF f, b {,a} Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: 0 → f Status Affected: None Encoding: 1001 bbba ffff ffff Description: Bit ‘b’ in register ‘f’ is cleared. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BCF FLAG_REG, 7, 0 Before Instruction FLAG_REG = C7h After Instruction FLAG_REG = 47h BN Branch if Negative Syntax: BN n Operands: -128 ≤ n ≤ 127 Operation: if Negative bit is ‘1’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0110 nnnn nnnn Description: If the Negative bit is ‘1’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BN Jump Before Instruction PC = address (HERE) After Instruction If Negative = 1; PC = address (Jump) If Negative = 0; PC = address (HERE + 2)© 2008 Microchip Technology Inc. DS39631E-page 277 PIC18F2420/2520/4420/4520 BNC Branch if Not Carry Syntax: BNC n Operands: -128 ≤ n ≤ 127 Operation: if Carry bit is ‘0’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0011 nnnn nnnn Description: If the Carry bit is ‘0’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNC Jump Before Instruction PC = address (HERE) After Instruction If Carry = 0; PC = address (Jump) If Carry = 1; PC = address (HERE + 2) BNN Branch if Not Negative Syntax: BNN n Operands: -128 ≤ n ≤ 127 Operation: if Negative bit is ‘0’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0111 nnnn nnnn Description: If the Negative bit is ‘0’, then the program will branch. The 2’s complement number ‘2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNN Jump Before Instruction PC = address (HERE) After Instruction If Negative = 0; PC = address (Jump) If Negative = 1; PC = address (HERE + 2)PIC18F2420/2520/4420/4520 DS39631E-page 278 © 2008 Microchip Technology Inc. BNOV Branch if Not Overflow Syntax: BNOV n Operands: -128 ≤ n ≤ 127 Operation: if Overflow bit is ‘0’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0101 nnnn nnnn Description: If the Overflow bit is ‘0’, then the program will branch. The 2’s complement number, ‘2n’, is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNOV Jump Before Instruction PC = address (HERE) After Instruction If Overflow = 0; PC = address (Jump) If Overflow = 1; PC = address (HERE + 2) BNZ Branch if Not Zero Syntax: BNZ n Operands: -128 ≤ n ≤ 127 Operation: if Zero bit is ‘0’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0001 nnnn nnnn Description: If the Zero bit is ‘0’, then the program will branch. The 2’s complement number, ‘2n’, is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BNZ Jump Before Instruction PC = address (HERE) After Instruction If Zero = 0; PC = address (Jump) If Zero = 1; PC = address (HERE + 2)© 2008 Microchip Technology Inc. DS39631E-page 279 PIC18F2420/2520/4420/4520 BRA Unconditional Branch Syntax: BRA n Operands: -1024 ≤ n ≤ 1023 Operation: (PC) + 2 + 2n → PC Status Affected: None Encoding: 1101 0nnn nnnn nnnn Description: Add the 2’s complement number, ‘2n’, to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation Example: HERE BRA Jump Before Instruction PC = address (HERE) After Instruction PC = address (Jump) BSF Bit Set f Syntax: BSF f, b {,a} Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: 1 → f Status Affected: None Encoding: 1000 bbba ffff ffff Description: Bit ‘b’ in register ‘f’ is set. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BSF FLAG_REG, 7, 1 Before Instruction FLAG_REG = 0Ah After Instruction FLAG_REG = 8AhPIC18F2420/2520/4420/4520 DS39631E-page 280 © 2008 Microchip Technology Inc. BTFSC Bit Test File, Skip if Clear Syntax: BTFSC f, b {,a} Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: skip if (f) = 0 Status Affected: None Encoding: 1011 bbba ffff ffff Description: If bit ‘b’ in register ‘f’ is ‘0’, then the next instruction is skipped. If bit ‘b’ is ‘0’, then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSC : : FLAG, 1, 0 Before Instruction PC = address (HERE) After Instruction If FLAG<1> = 0; PC = address (TRUE) If FLAG<1> = 1; PC = address (FALSE) BTFSS Bit Test File, Skip if Set Syntax: BTFSS f, b {,a} Operands: 0 ≤ f ≤ 255 0 ≤ b < 7 a ∈ [0,1] Operation: skip if (f) = 1 Status Affected: None Encoding: 1010 bbba ffff ffff Description: If bit ‘b’ in register ‘f’ is ‘1’, then the next instruction is skipped. If bit ‘b’ is ‘1’, then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSS : : FLAG, 1, 0 Before Instruction PC = address (HERE) After Instruction If FLAG<1> = 0; PC = address (FALSE) If FLAG<1> = 1; PC = address (TRUE)© 2008 Microchip Technology Inc. DS39631E-page 281 PIC18F2420/2520/4420/4520 BTG Bit Toggle f Syntax: BTG f, b {,a} Operands: 0 ≤ f ≤ 255 0 ≤ b < 7 a ∈ [0,1] Operation: (f) → f Status Affected: None Encoding: 0111 bbba ffff ffff Description: Bit ‘b’ in data memory location ‘f’ is inverted. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BTG PORTC, 4, 0 Before Instruction: PORTC = 0111 0101 [75h] After Instruction: PORTC = 0110 0101 [65h] BOV Branch if Overflow Syntax: BOV n Operands: -128 ≤ n ≤ 127 Operation: if Overflow bit is ‘1’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0100 nnnn nnnn Description: If the Overflow bit is ‘1’, then the program will branch. The 2’s complement number, ‘2n’, is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BOV Jump Before Instruction PC = address (HERE) After Instruction If Overflow = 1; PC = address (Jump) If Overflow = 0; PC = address (HERE + 2)PIC18F2420/2520/4420/4520 DS39631E-page 282 © 2008 Microchip Technology Inc. BZ Branch if Zero Syntax: BZ n Operands: -128 ≤ n ≤ 127 Operation: if Zero bit is ‘1’, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0000 nnnn nnnn Description: If the Zero bit is ‘1’, then the program will branch. The 2’s complement number, ‘2n’, is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE BZ Jump Before Instruction PC = address (HERE) After Instruction If Zero = 1; PC = address (Jump) If Zero = 0; PC = address (HERE + 2) CALL Subroutine Call Syntax: CALL k {,s} Operands: 0 ≤ k ≤ 1048575 s ∈ [0,1] Operation: (PC) + 4 → TOS, k → PC<20:1>; if s = 1, (W) → WS, (STATUS) → STATUSS, (BSR) → BSRS Status Affected: None Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 110s k19kkk k7kkk kkkk kkkk0 kkkk8 Description: Subroutine call of entire 2-Mbyte memory range. First, return address (PC + 4) is pushed onto the return stack. If ‘s’ = 1, the W, STATUS and BSR registers are also pushed into their respective shadow registers, WS, STATUSS and BSRS. If ‘s’ = 0, no update occurs (default). Then, the 20-bit value ‘k’ is loaded into PC<20:1>. CALL is a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’<7:0>, PUSH PC to stack Read literal ‘k’<19:8>, Write to PC No operation No operation No operation No operation Example: HERE CALL THERE, 1 Before Instruction PC = address (HERE) After Instruction PC = address (THERE) TOS = address (HERE + 4) WS = W BSRS = BSR STATUSS = STATUS© 2008 Microchip Technology Inc. DS39631E-page 283 PIC18F2420/2520/4420/4520 CLRF Clear f Syntax: CLRF f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: 000h → f, 1 → Z Status Affected: Z Encoding: 0110 101a ffff ffff Description: Clears the contents of the specified register. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: CLRF FLAG_REG, 1 Before Instruction FLAG_REG = 5Ah After Instruction FLAG_REG = 00h CLRWDT Clear Watchdog Timer Syntax: CLRWDT Operands: None Operation: 000h → WDT, 000h → WDT postscaler, 1 → TO, 1 → PD Status Affected: TO, PD Encoding: 0000 0000 0000 0100 Description: CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits, TO and PD, are set. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data No operation Example: CLRWDT Before Instruction WDT Counter = ? After Instruction WDT Counter = 00h WDT Postscaler = 0 TO = 1 PD = 1PIC18F2420/2520/4420/4520 DS39631E-page 284 © 2008 Microchip Technology Inc. COMF Complement f Syntax: COMF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest Status Affected: N, Z Encoding: 0001 11da ffff ffff Description: The contents of register ‘f’ are complemented. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: COMF REG, 0, 0 Before Instruction REG = 13h After Instruction REG = 13h W = ECh CPFSEQ Compare f with W, Skip if f = W Syntax: CPFSEQ f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) = (W) (unsigned comparison) Status Affected: None Encoding: 0110 001a ffff ffff Description: Compares the contents of data memory location ‘f’ to the contents of W by performing an unsigned subtraction. If ‘f’ = W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSEQ REG, 0 NEQUAL : EQUAL : Before Instruction PC Address = HERE W =? REG = ? After Instruction If REG = W; PC = Address (EQUAL) If REG ≠ W; PC = Address (NEQUAL)© 2008 Microchip Technology Inc. DS39631E-page 285 PIC18F2420/2520/4420/4520 CPFSGT Compare f with W, Skip if f > W Syntax: CPFSGT f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) > (W) (unsigned comparison) Status Affected: None Encoding: 0110 010a ffff ffff Description: Compares the contents of data memory location ‘f’ to the contents of the W by performing an unsigned subtraction. If the contents of ‘f’ are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSGT REG, 0 NGREATER : GREATER : Before Instruction PC = Address (HERE) W = ? After Instruction If REG > W; PC = Address (GREATER) If REG ≤ W; PC = Address (NGREATER) CPFSLT Compare f with W, Skip if f < W Syntax: CPFSLT f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) < (W) (unsigned comparison) Status Affected: None Encoding: 0110 000a ffff ffff Description: Compares the contents of data memory location ‘f’ to the contents of W by performing an unsigned subtraction. If the contents of ‘f’ are less than the contents of W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSLT REG, 1 NLESS : LESS : Before Instruction PC = Address (HERE) W = ? After Instruction If REG < W; PC = Address (LESS) If REG ≥ W; PC = Address (NLESS)PIC18F2420/2520/4420/4520 DS39631E-page 286 © 2008 Microchip Technology Inc. DAW Decimal Adjust W Register Syntax: DAW Operands: None Operation: If [W<3:0> > 9] or [DC = 1] then, (W<3:0>) + 6 → W<3:0>; else, (W<3:0>) → W<3:0>; If [W<7:4> + DC > 9] or [C = 1] then, (W<7:4>) + 6 + DC → W<7:4>; else, (W<7:4>) + DC → W<7:4> Status Affected: C Encoding: 0000 0000 0000 0111 Description: DAW adjusts the 8-bit value in W, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register W Process Data Write W Example 1: DAW Before Instruction W = A5h C =0 DC = 0 After Instruction W = 05h C =1 DC = 0 Example 2: Before Instruction W = CEh C =0 DC = 0 After Instruction W = 34h C =1 DC = 0 DECF Decrement f Syntax: DECF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest Status Affected: C, DC, N, OV, Z Encoding: 0000 01da ffff ffff Description: Decrement register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: DECF CNT, 1, 0 Before Instruction CNT = 01h Z =0 After Instruction CNT = 00h Z =1© 2008 Microchip Technology Inc. DS39631E-page 287 PIC18F2420/2520/4420/4520 DECFSZ Decrement f, Skip if 0 Syntax: DECFSZ f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest, skip if result = 0 Status Affected: None Encoding: 0010 11da ffff ffff Description: The contents of register ‘f’ are decremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE DECFSZ CNT, 1, 1 GOTO LOOP CONTINUE Before Instruction PC = Address (HERE) After Instruction CNT = CNT – 1 If CNT = 0; PC = Address (CONTINUE) If CNT ≠ 0; PC = Address (HERE + 2) DCFSNZ Decrement f, Skip if Not 0 Syntax: DCFSNZ f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest, skip if result ≠ 0 Status Affected: None Encoding: 0100 11da ffff ffff Description: The contents of register ‘f’ are decremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is not ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE DCFSNZ TEMP, 1, 0 ZERO : NZERO : Before Instruction TEMP = ? After Instruction TEMP = TEMP – 1, If TEMP = 0; PC = Address (ZERO) If TEMP ≠ 0; PC = Address (NZERO)PIC18F2420/2520/4420/4520 DS39631E-page 288 © 2008 Microchip Technology Inc. GOTO Unconditional Branch Syntax: GOTO k Operands: 0 ≤ k ≤ 1048575 Operation: k → PC<20:1> Status Affected: None Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8 Description: GOTO allows an unconditional branch anywhere within entire 2-Mbyte memory range. The 20-bit value ‘k’ is loaded into PC<20:1>. GOTO is always a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’<7:0>, No operation Read literal ‘k’<19:8>, Write to PC No operation No operation No operation No operation Example: GOTO THERE After Instruction PC = Address (THERE) INCF Increment f Syntax: INCF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest Status Affected: C, DC, N, OV, Z Encoding: 0010 10da ffff ffff Description: The contents of register ‘f’ are incremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: INCF CNT, 1, 0 Before Instruction CNT = FFh Z =0 C =? DC = ? After Instruction CNT = 00h Z =1 C =1 DC = 1© 2008 Microchip Technology Inc. DS39631E-page 289 PIC18F2420/2520/4420/4520 INCFSZ Increment f, Skip if 0 Syntax: INCFSZ f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest, skip if result = 0 Status Affected: None Encoding: 0011 11da ffff ffff Description: The contents of register ‘f’ are incremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE INCFSZ CNT, 1, 0 NZERO : ZERO : Before Instruction PC = Address (HERE) After Instruction CNT = CNT + 1 If CNT = 0; PC = Address (ZERO) If CNT ≠ 0; PC = Address (NZERO) INFSNZ Increment f, Skip if Not 0 Syntax: INFSNZ f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest, skip if result ≠ 0 Status Affected: None Encoding: 0100 10da ffff ffff Description: The contents of register ‘f’ are incremented. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If the result is not ‘0’, the next instruction, which is already fetched, is discarded and a NOP is executed instead, making it a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE INFSNZ REG, 1, 0 ZERO NZERO Before Instruction PC = Address (HERE) After Instruction REG = REG + 1 If REG ≠ 0; PC = Address (NZERO) If REG = 0; PC = Address (ZERO)PIC18F2420/2520/4420/4520 DS39631E-page 290 © 2008 Microchip Technology Inc. IORLW Inclusive OR Literal with W Syntax: IORLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .OR. k → W Status Affected: N, Z Encoding: 0000 1001 kkkk kkkk Description: The contents of W are ORed with the 8-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: IORLW 35h Before Instruction W = 9Ah After Instruction W = BFh IORWF Inclusive OR W with f Syntax: IORWF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .OR. (f) → dest Status Affected: N, Z Encoding: 0001 00da ffff ffff Description: Inclusive OR W with register ‘f’. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: IORWF RESULT, 0, 1 Before Instruction RESULT = 13h W = 91h After Instruction RESULT = 13h W = 93h© 2008 Microchip Technology Inc. DS39631E-page 291 PIC18F2420/2520/4420/4520 LFSR Load FSR Syntax: LFSR f, k Operands: 0 ≤ f ≤ 2 0 ≤ k ≤ 4095 Operation: k → FSRf Status Affected: None Encoding: 1110 1111 1110 0000 00ff k7kkk k11kkk kkkk Description: The 12-bit literal ‘k’ is loaded into the File Select Register pointed to by ‘f’. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ MSB Process Data Write literal ‘k’ MSB to FSRfH Decode Read literal ‘k’ LSB Process Data Write literal ‘k’ to FSRfL Example: LFSR 2, 3ABh After Instruction FSR2H = 03h FSR2L = ABh MOVF Move f Syntax: MOVF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: f → dest Status Affected: N, Z Encoding: 0101 00da ffff ffff Description: The contents of register ‘f’ are moved to a destination dependent upon the status of ‘d’. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). Location ‘f’ can be anywhere in the 256-byte bank. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write W Example: MOVF REG, 0, 0 Before Instruction REG = 22h W = FFh After Instruction REG = 22h W = 22hPIC18F2420/2520/4420/4520 DS39631E-page 292 © 2008 Microchip Technology Inc. MOVFF Move f to f Syntax: MOVFF fs,fd Operands: 0 ≤ fs ≤ 4095 0 ≤ fd ≤ 4095 Operation: (fs) → fd Status Affected: None Encoding: 1st word (source) 2nd word (destin.) 1100 1111 ffff ffff ffff ffff ffffs ffffd Description: The contents of source register ‘fs’ are moved to destination register ‘fd’. Location of source ‘fs’ can be anywhere in the 4096-byte data space (000h to FFFh) and location of destination ‘fd’ can also be anywhere from 000h to FFFh. Either source or destination can be W (a useful special situation). MOVFF is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). The MOVFF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. Words: 2 Cycles: 2 (3) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ (src) Process Data No operation Decode No operation No dummy read No operation Write register ‘f’ (dest) Example: MOVFF REG1, REG2 Before Instruction REG1 = 33h REG2 = 11h After Instruction REG1 = 33h REG2 = 33h MOVLB Move Literal to Low Nibble in BSR Syntax: MOVLW k Operands: 0 ≤ k ≤ 255 Operation: k → BSR Status Affected: None Encoding: 0000 0001 kkkk kkkk Description: The 8-bit literal ‘k’ is loaded into the Bank Select Register (BSR). The value of BSR<7:4> always remains ‘0’, regardless of the value of k7:k4. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write literal ‘k’ to BSR Example: MOVLB 5 Before Instruction BSR Register = 02h After Instruction BSR Register = 05h© 2008 Microchip Technology Inc. DS39631E-page 293 PIC18F2420/2520/4420/4520 MOVLW Move Literal to W Syntax: MOVLW k Operands: 0 ≤ k ≤ 255 Operation: k → W Status Affected: None Encoding: 0000 1110 kkkk kkkk Description: The 8-bit literal ‘k’ is loaded into W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: MOVLW 5Ah After Instruction W = 5Ah MOVWF Move W to f Syntax: MOVWF f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (W) → f Status Affected: None Encoding: 0110 111a ffff ffff Description: Move data from W to register ‘f’. Location ‘f’ can be anywhere in the 256-byte bank. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: MOVWF REG, 0 Before Instruction W = 4Fh REG = FFh After Instruction W = 4Fh REG = 4FhPIC18F2420/2520/4420/4520 DS39631E-page 294 © 2008 Microchip Technology Inc. MULLW Multiply Literal with W Syntax: MULLW k Operands: 0 ≤ k ≤ 255 Operation: (W) x k → PRODH:PRODL Status Affected: None Encoding: 0000 1101 kkkk kkkk Description: An unsigned multiplication is carried out between the contents of W and the 8-bit literal ‘k’. The 16-bit result is placed in the PRODH:PRODL register pair. PRODH contains the high byte. W is unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A zero result is possible but not detected. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write registers PRODH: PRODL Example: MULLW 0C4h Before Instruction W = E2h PRODH = ? PRODL = ? After Instruction W = E2h PRODH = ADh PRODL = 08h MULWF Multiply W with f Syntax: MULWF f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (W) x (f) → PRODH:PRODL Status Affected: None Encoding: 0000 001a ffff ffff Description: An unsigned multiplication is carried out between the contents of W and the register file location ‘f’. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both W and ‘f’ are unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A zero result is possible but not detected. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write registers PRODH: PRODL Example: MULWF REG, 1 Before Instruction W = C4h REG = B5h PRODH = ? PRODL = ? After Instruction W = C4h REG = B5h PRODH = 8Ah PRODL = 94h© 2008 Microchip Technology Inc. DS39631E-page 295 PIC18F2420/2520/4420/4520 NEGF Negate f Syntax: NEGF f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: ( f ) + 1 → f Status Affected: N, OV, C, DC, Z Encoding: 0110 110a ffff ffff Description: Location ‘f’ is negated using two’s complement. The result is placed in the data memory location ‘f’. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: NEGF REG, 1 Before Instruction REG = 0011 1010 [3Ah] After Instruction REG = 1100 0110 [C6h] NOP No Operation Syntax: NOP Operands: None Operation: No operation Status Affected: None Encoding: 0000 1111 0000 xxxx 0000 xxxx 0000 xxxx Description: No operation. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation Example: None.PIC18F2420/2520/4420/4520 DS39631E-page 296 © 2008 Microchip Technology Inc. POP Pop Top of Return Stack Syntax: POP Operands: None Operation: (TOS) → bit bucket Status Affected: None Encoding: 0000 0000 0000 0110 Description: The TOS value is pulled off the return stack and is discarded. The TOS value then becomes the previous value that was pushed onto the return stack. This instruction is provided to enable the user to properly manage the return stack to incorporate a software stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation POP TOS value No operation Example: POP GOTO NEW Before Instruction TOS = 0031A2h Stack (1 level down) = 014332h After Instruction TOS = 014332h PC = NEW PUSH Push Top of Return Stack Syntax: PUSH Operands: None Operation: (PC + 2) → TOS Status Affected: None Encoding: 0000 0000 0000 0101 Description: The PC + 2 is pushed onto the top of the return stack. The previous TOS value is pushed down on the stack. This instruction allows implementing a software stack by modifying TOS and then pushing it onto the return stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode PUSH PC + 2 onto return stack No operation No operation Example: PUSH Before Instruction TOS = 345Ah PC = 0124h After Instruction PC = 0126h TOS = 0126h Stack (1 level down) = 345Ah© 2008 Microchip Technology Inc. DS39631E-page 297 PIC18F2420/2520/4420/4520 RCALL Relative Call Syntax: RCALL n Operands: -1024 ≤ n ≤ 1023 Operation: (PC) + 2 → TOS, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1101 1nnn nnnn nnnn Description: Subroutine call with a jump up to 1K from the current location. First, return address (PC + 2) is pushed onto the stack. Then, add the 2’s complement number ‘2n’ to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ PUSH PC to stack Process Data Write to PC No operation No operation No operation No operation Example: HERE RCALL Jump Before Instruction PC = Address (HERE) After Instruction PC = Address (Jump) TOS = Address (HERE + 2) RESET Reset Syntax: RESET Operands: None Operation: Reset all registers and flags that are affected by a MCLR Reset. Status Affected: All Encoding: 0000 0000 1111 1111 Description: This instruction provides a way to execute a MCLR Reset in software. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Start Reset No operation No operation Example: RESET After Instruction Registers = Reset Value Flags* = Reset ValuePIC18F2420/2520/4420/4520 DS39631E-page 298 © 2008 Microchip Technology Inc. RETFIE Return from Interrupt Syntax: RETFIE {s} Operands: s ∈ [0,1] Operation: (TOS) → PC, 1 → GIE/GIEH or PEIE/GIEL; if s = 1, (WS) → W, (STATUSS) → STATUS, (BSRS) → BSR, PCLATU, PCLATH are unchanged Status Affected: GIE/GIEH, PEIE/GIEL. Encoding: 0000 0000 0001 000s Description: Return from interrupt. Stack is popped and Top-of-Stack (TOS) is loaded into the PC. Interrupts are enabled by setting either the high or low-priority global interrupt enable bit. If ‘s’ = 1, the contents of the shadow registers, WS, STATUSS and BSRS, are loaded into their corresponding registers, W, STATUS and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation POP PC from stack Set GIEH or GIEL No operation No operation No operation No operation Example: RETFIE 1 After Interrupt PC = TOS W = WS BSR = BSRS STATUS = STATUSS GIE/GIEH, PEIE/GIEL = 1 RETLW Return Literal to W Syntax: RETLW k Operands: 0 ≤ k ≤ 255 Operation: k → W, (TOS) → PC, PCLATU, PCLATH are unchanged Status Affected: None Encoding: 0000 1100 kkkk kkkk Description: W is loaded with the 8-bit literal ‘k’. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data POP PC from stack, Write to W No operation No operation No operation No operation Example: CALL TABLE ; W contains table ; offset value ; W now has ; table value : TABLE ADDWF PCL ; W = offset RETLW k0 ; Begin table RETLW k1 ; : : RETLW kn ; End of table Before Instruction W = 07h After Instruction W = value of kn© 2008 Microchip Technology Inc. DS39631E-page 299 PIC18F2420/2520/4420/4520 RETURN Return from Subroutine Syntax: RETURN {s} Operands: s ∈ [0,1] Operation: (TOS) → PC; if s = 1, (WS) → W, (STATUSS) → STATUS, (BSRS) → BSR, PCLATU, PCLATH are unchanged Status Affected: None Encoding: 0000 0000 0001 001s Description: Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter. If ‘s’= 1, the contents of the shadow registers, WS, STATUSS and BSRS, are loaded into their corresponding registers, W, STATUS and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data POP PC from stack No operation No operation No operation No operation Example: RETURN After Instruction: PC = TOS RLCF Rotate Left f through Carry Syntax: RLCF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<7>) → C, (C) → dest<0> Status Affected: C, N, Z Encoding: 0011 01da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the left through the Carry flag. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: RLCF REG, 0, 0 Before Instruction REG = 1110 0110 C =0 After Instruction REG = 1110 0110 W = 1100 1100 C =1 C register fPIC18F2420/2520/4420/4520 DS39631E-page 300 © 2008 Microchip Technology Inc. RLNCF Rotate Left f (No Carry) Syntax: RLNCF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<7>) → dest<0> Status Affected: N, Z Encoding: 0100 01da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the left. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: RLNCF REG, 1, 0 Before Instruction REG = 1010 1011 After Instruction REG = 0101 0111 register f RRCF Rotate Right f through Carry Syntax: RRCF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<0>) → C, (C) → dest<7> Status Affected: C, N, Z Encoding: 0011 00da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the right through the Carry flag. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: RRCF REG, 0, 0 Before Instruction REG = 1110 0110 C =0 After Instruction REG = 1110 0110 W = 0111 0011 C =0 C register f© 2008 Microchip Technology Inc. DS39631E-page 301 PIC18F2420/2520/4420/4520 RRNCF Rotate Right f (No Carry) Syntax: RRNCF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<0>) → dest<7> Status Affected: N, Z Encoding: 0100 00da ffff ffff Description: The contents of register ‘f’ are rotated one bit to the right. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank will be selected, overriding the BSR value. If ‘a’ is ‘1’, then the bank will be selected as per the BSR value (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: RRNCF REG, 1, 0 Before Instruction REG = 1101 0111 After Instruction REG = 1110 1011 Example 2: RRNCF REG, 0, 0 Before Instruction W =? REG = 1101 0111 After Instruction W = 1110 1011 REG = 1101 0111 register f SETF Set f Syntax: SETF f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: FFh → f Status Affected: None Encoding: 0110 100a ffff ffff Description: The contents of the specified register are set to FFh. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: SETF REG, 1 Before Instruction REG = 5Ah After Instruction REG = FFhPIC18F2420/2520/4420/4520 DS39631E-page 302 © 2008 Microchip Technology Inc. SLEEP Enter Sleep mode Syntax: SLEEP Operands: None Operation: 00h → WDT, 0 → WDT postscaler, 1 → TO, 0 → PD Status Affected: TO, PD Encoding: 0000 0000 0000 0011 Description: The Power-Down status bit (PD) is cleared. The Time-out status bit (TO) is set. Watchdog Timer and its postscaler are cleared. The processor is put into Sleep mode with the oscillator stopped. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data Go to Sleep Example: SLEEP Before Instruction TO = ? PD = ? After Instruction TO = 1 † PD = 0 † If WDT causes wake-up, this bit is cleared. SUBFWB Subtract f from W with Borrow Syntax: SUBFWB f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) – (f) – (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 01da ffff ffff Description: Subtract register ‘f’ and Carry flag (borrow) from W (2’s complement method). If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: SUBFWB REG, 1, 0 Before Instruction REG = 3 W =2 C =1 After Instruction REG = FF W =2 C =0 Z =0 N = 1 ; result is negative Example 2: SUBFWB REG, 0, 0 Before Instruction REG = 2 W =5 C =1 After Instruction REG = 2 W =3 C =1 Z =0 N = 0 ; result is positive Example 3: SUBFWB REG, 1, 0 Before Instruction REG = 1 W =2 C =0 After Instruction REG = 0 W =2 C =1 Z = 1 ; result is zero N =0© 2008 Microchip Technology Inc. DS39631E-page 303 PIC18F2420/2520/4420/4520 SUBLW Subtract W from Literal Syntax: SUBLW k Operands: 0 ≤ k ≤ 255 Operation: k – (W) → W Status Affected: N, OV, C, DC, Z Encoding: 0000 1000 kkkk kkkk Description W is subtracted from the 8-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example 1: SUBLW 02h Before Instruction W = 01h C =? After Instruction W = 01h C = 1 ; result is positive Z =0 N =0 Example 2: SUBLW 02h Before Instruction W = 02h C =? After Instruction W = 00h C = 1 ; result is zero Z =1 N =0 Example 3: SUBLW 02h Before Instruction W = 03h C =? After Instruction W = FFh ; (2’s complement) C = 0 ; result is negative Z =0 N =1 SUBWF Subtract W from f Syntax: SUBWF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – (W) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 11da ffff ffff Description: Subtract W from register ‘f’ (2’s complement method). If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: SUBWF REG, 1, 0 Before Instruction REG = 3 W =2 C =? After Instruction REG = 1 W =2 C = 1 ; result is positive Z =0 N =0 Example 2: SUBWF REG, 0, 0 Before Instruction REG = 2 W =2 C =? After Instruction REG = 2 W =0 C = 1 ; result is zero Z =1 N =0 Example 3: SUBWF REG, 1, 0 Before Instruction REG = 1 W =2 C =? After Instruction REG = FFh ;(2’s complement) W =2 C = 0 ; result is negative Z =0 N =1PIC18F2420/2520/4420/4520 DS39631E-page 304 © 2008 Microchip Technology Inc. SUBWFB Subtract W from f with Borrow Syntax: SUBWFB f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – (W) – (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 10da ffff ffff Description: Subtract W and the Carry flag (borrow) from register ‘f’ (2’s complement method). If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example 1: SUBWFB REG, 1, 0 Before Instruction REG = 19h (0001 1001) W = 0Dh (0000 1101) C =1 After Instruction REG = 0Ch (0000 1011) W = 0Dh (0000 1101) C =1 Z =0 N = 0 ; result is positive Example 2: SUBWFB REG, 0, 0 Before Instruction REG = 1Bh (0001 1011) W = 1Ah (0001 1010) C =0 After Instruction REG = 1Bh (0001 1011) W = 00h C =1 Z = 1 ; result is zero N =0 Example 3: SUBWFB REG, 1, 0 Before Instruction REG = 03h (0000 0011) W = 0Eh (0000 1101) C =1 After Instruction REG = F5h (1111 0100) ; [2’s comp] W = 0Eh (0000 1101) C =0 Z =0 N = 1 ; result is negative SWAPF Swap f Syntax: SWAPF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f<3:0>) → dest<7:4>, (f<7:4>) → dest<3:0> Status Affected: None Encoding: 0011 10da ffff ffff Description: The upper and lower nibbles of register ‘f’ are exchanged. If ‘d’ is ‘0’, the result is placed in W. If ‘d’ is ‘1’, the result is placed in register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: SWAPF REG, 1, 0 Before Instruction REG = 53h After Instruction REG = 35h© 2008 Microchip Technology Inc. DS39631E-page 305 PIC18F2420/2520/4420/4520 TBLRD Table Read Syntax: TBLRD ( *; *+; *-; +*) Operands: None Operation: if TBLRD *, (Prog Mem (TBLPTR)) → TABLAT, TBLPTR – No Change; if TBLRD *+, (Prog Mem (TBLPTR)) → TABLAT, (TBLPTR) + 1 → TBLPTR; if TBLRD *-, (Prog Mem (TBLPTR)) → TABLAT, (TBLPTR) – 1 → TBLPTR; if TBLRD +*, (TBLPTR) + 1 → TBLPTR, (Prog Mem (TBLPTR)) → TABLAT Status Affected: None Encoding: 0000 0000 0000 10nn nn=0 * =1 *+ =2 *- =3 +* Description: This instruction is used to read the contents of Program Memory (P.M.). To address the program memory, a pointer called Table Pointer (TBLPTR) is used. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-Mbyte address range. TBLPTR<0> = 0:Least Significant Byte of Program Memory Word TBLPTR<0> = 1:Most Significant Byte of Program Memory Word The TBLRD instruction can modify the value of TBLPTR as follows: • no change • post-increment • post-decrement • pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read Program Memory) No operation No operation (Write TABLAT) TBLRD Table Read (Continued) Example1: TBLRD *+ ; Before Instruction TABLAT = 55h TBLPTR = 00A356h MEMORY (00A356h) = 34h After Instruction TABLAT = 34h TBLPTR = 00A357h Example2: TBLRD +* ; Before Instruction TABLAT = AAh TBLPTR = 01A357h MEMORY (01A357h) = 12h MEMORY (01A358h) = 34h After Instruction TABLAT = 34h TBLPTR = 01A358hPIC18F2420/2520/4420/4520 DS39631E-page 306 © 2008 Microchip Technology Inc. TBLWT Table Write Syntax: TBLWT ( *; *+; *-; +*) Operands: None Operation: if TBLWT*, (TABLAT) → Holding Register, TBLPTR – No Change; if TBLWT*+, (TABLAT) → Holding Register, (TBLPTR) + 1 → TBLPTR; if TBLWT*-, (TABLAT) → Holding Register, (TBLPTR) – 1 → TBLPTR; if TBLWT+*, (TBLPTR) + 1 → TBLPTR, (TABLAT) → Holding Register Status Affected: None Encoding: 0000 0000 0000 11nn nn=0 * =1 *+ =2 *- =3 +* Description: This instruction uses the 3 LSBs of TBLPTR to determine which of the 8 holding registers the TABLAT is written to. The holding registers are used to program the contents of Program Memory (P.M.). (Refer to Section 6.0 “Flash Program Memory” for additional details on programming Flash memory.) The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-MByte address range. The LSb of the TBLPTR selects which byte of the program memory location to access. TBLPTR<0> = 0:Least Significant Byte of Program Memory Word TBLPTR<0> = 1:Most Significant Byte of Program Memory Word The TBLWT instruction can modify the value of TBLPTR as follows: • no change • post-increment • post-decrement • pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read TABLAT) No operation No operation (Write to Holding Register ) TBLWT Table Write (Continued) Example1: TBLWT *+; Before Instruction TABLAT = 55h TBLPTR = 00A356h HOLDING REGISTER (00A356h) = FFh After Instructions (table write completion) TABLAT = 55h TBLPTR = 00A357h HOLDING REGISTER (00A356h) = 55h Example 2: TBLWT +*; Before Instruction TABLAT = 34h TBLPTR = 01389Ah HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = FFh After Instruction (table write completion) TABLAT = 34h TBLPTR = 01389Bh HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = 34h © 2008 Microchip Technology Inc. DS39631E-page 307 PIC18F2420/2520/4420/4520 TSTFSZ Test f, Skip if 0 Syntax: TSTFSZ f {,a} Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: skip if f = 0 Status Affected: None Encoding: 0110 011a ffff ffff Description: If ‘f’ = 0, the next instruction fetched during the current instruction execution is discarded and a NOP is executed, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE TSTFSZ CNT, 1 NZERO : ZERO : Before Instruction PC = Address (HERE) After Instruction If CNT = 00h, PC = Address (ZERO) If CNT ≠ 00h, PC = Address (NZERO) XORLW Exclusive OR Literal with W Syntax: XORLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .XOR. k → W Status Affected: N, Z Encoding: 0000 1010 kkkk kkkk Description: The contents of W are XORed with the 8-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example: XORLW 0AFh Before Instruction W = B5h After Instruction W = 1AhPIC18F2420/2520/4420/4520 DS39631E-page 308 © 2008 Microchip Technology Inc. XORWF Exclusive OR W with f Syntax: XORWF f {,d {,a}} Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .XOR. (f) → dest Status Affected: N, Z Encoding: 0001 10da ffff ffff Description: Exclusive OR the contents of W with register ‘f’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in the register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f ≤ 95 (5Fh). See Section 24.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: XORWF REG, 1, 0 Before Instruction REG = AFh W = B5h After Instruction REG = 1Ah W = B5h© 2008 Microchip Technology Inc. DS39631E-page 309 PIC18F2420/2520/4420/4520 24.2 Extended Instruction Set In addition to the standard 75 instructions of the PIC18 instruction set, PIC18F2420/2520/4420/4520 devices also provide an optional extension to the core CPU functionality. The added features include eight additional instructions that augment indirect and indexed addressing operations and the implementation of Indexed Literal Offset Addressing mode for many of the standard PIC18 instructions. The additional features of the extended instruction set are disabled by default. To enable them, users must set the XINST Configuration bit. The instructions in the extended set can all be classified as literal operations, which either manipulate the File Select Registers, or use them for indexed addressing. Two of the instructions, ADDFSR and SUBFSR, each have an additional special instantiation for using FSR2. These versions (ADDULNK and SUBULNK) allow for automatic return after execution. The extended instructions are specifically implemented to optimize re-entrant program code (that is, code that is recursive or that uses a software stack) written in high-level languages, particularly C. Among other things, they allow users working in high-level languages to perform certain operations on data structures more efficiently. These include: • Dynamic allocation and deallocation of software stack space when entering and leaving subroutines • Function Pointer invocation • Software Stack Pointer manipulation • Manipulation of variables located in a software stack A summary of the instructions in the extended instruction set is provided in Table 24-3. Detailed descriptions are provided in Section 24.2.2 “Extended Instruction Set”. The opcode field descriptions in Table 24-1 (page 268) apply to both the standard and extended PIC18 instruction sets. 24.2.1 EXTENDED INSTRUCTION SYNTAX Most of the extended instructions use indexed arguments, using one of the File Select Registers and some offset to specify a source or destination register. When an argument for an instruction serves as part of indexed addressing, it is enclosed in square brackets (“[ ]”). This is done to indicate that the argument is used as an index or offset. MPASM™ Assembler will flag an error if it determines that an index or offset value is not bracketed. When the extended instruction set is enabled, brackets are also used to indicate index arguments in byteoriented and bit-oriented instructions. This is in addition to other changes in their syntax. For more details, see Section 24.2.3.1 “Extended Instruction Syntax with Standard PIC18 Commands”. TABLE 24-3: EXTENSIONS TO THE PIC18 INSTRUCTION SET Note: The instruction set extension and the Indexed Literal Offset Addressing mode were designed for optimizing applications written in C; the user may likely never use these instructions directly in assembler. The syntax for these commands is provided as a reference for users who may be reviewing code that has been generated by a compiler. Note: In the past, square brackets have been used to denote optional arguments in the PIC18 and earlier instruction sets. In this text and going forward, optional arguments are denoted by braces (“{ }”). Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status MSb LSb Affected ADDFSR ADDULNK CALLW MOVSF MOVSS PUSHL SUBFSR SUBULNK f, k k zs, fd zs, zd k f, k k Add Literal to FSR Add Literal to FSR2 and Return Call Subroutine using WREG Move zs (source) to 1st word fd (destination) 2nd word Move zs (source) to 1st word zd (destination) 2nd word Store Literal at FSR2, Decrement FSR2 Subtract Literal from FSR Subtract Literal from FSR2 and Return 1 2 2 2 2 1 1 2 1110 1110 0000 1110 1111 1110 1111 1110 1110 1110 1000 1000 0000 1011 ffff 1011 xxxx 1010 1001 1001 ffkk 11kk 0001 0zzz ffff 1zzz xzzz kkkk ffkk 11kk kkkk kkkk 0100 zzzz ffff zzzz zzzz kkkk kkkk kkkk None None None None None None None NonePIC18F2420/2520/4420/4520 DS39631E-page 310 © 2008 Microchip Technology Inc. 24.2.2 EXTENDED INSTRUCTION SET ADDFSR Add Literal to FSR Syntax: ADDFSR f, k Operands: 0 ≤ k ≤ 63 f ∈ [ 0, 1, 2 ] Operation: FSR(f) + k → FSR(f) Status Affected: None Encoding: 1110 1000 ffkk kkkk Description: The 6-bit literal ‘k’ is added to the contents of the FSR specified by ‘f’. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to FSR Example: ADDFSR 2, 23h Before Instruction FSR2 = 03FFh After Instruction FSR2 = 0422h ADDULNK Add Literal to FSR2 and Return Syntax: ADDULNK k Operands: 0 ≤ k ≤ 63 Operation: FSR2 + k → FSR2, (TOS) → PC Status Affected: None Encoding: 1110 1000 11kk kkkk Description: The 6-bit literal ‘k’ is added to the contents of FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. This may be thought of as a special case of the ADDFSR instruction, where f = 3 (binary ‘11’); it operates only on FSR2. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to FSR No Operation No Operation No Operation No Operation Example: ADDULNK 23h Before Instruction FSR2 = 03FFh PC = 0100h After Instruction FSR2 = 0422h PC = (TOS) Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction syntax then becomes: {label} instruction argument(s).© 2008 Microchip Technology Inc. DS39631E-page 311 PIC18F2420/2520/4420/4520 CALLW Subroutine Call Using WREG Syntax: CALLW Operands: None Operation: (PC + 2) → TOS, (W) → PCL, (PCLATH) → PCH, (PCLATU) → PCU Status Affected: None Encoding: 0000 0000 0001 0100 Description First, the return address (PC + 2) is pushed onto the return stack. Next, the contents of W are written to PCL; the existing value is discarded. Then, the contents of PCLATH and PCLATU are latched into PCH and PCU, respectively. The second cycle is executed as a NOP instruction while the new next instruction is fetched. Unlike CALL, there is no option to update W, STATUS or BSR. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read WREG PUSH PC to stack No operation No operation No operation No operation No operation Example: HERE CALLW Before Instruction PC = address (HERE) PCLATH = 10h PCLATU = 00h W = 06h After Instruction PC = 001006h TOS = address (HERE + 2) PCLATH = 10h PCLATU = 00h W = 06h MOVSF Move Indexed to f Syntax: MOVSF [zs], fd Operands: 0 ≤ zs ≤ 127 0 ≤ fd ≤ 4095 Operation: ((FSR2) + zs) → fd Status Affected: None Encoding: 1st word (source) 2nd word (destin.) 1110 1111 1011 ffff 0zzz ffff zzzzs ffffd Description: The contents of the source register are moved to destination register ‘fd’. The actual address of the source register is determined by adding the 7-bit literal offset ‘zs’ in the first word to the value of FSR2. The address of the destination register is specified by the 12-bit literal ‘fd’ in the second word. Both addresses can be anywhere in the 4096-byte data space (000h to FFFh). The MOVSF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an indirect addressing register, the value returned will be 00h. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Determine source addr Determine source addr Read source reg Decode No operation No dummy read No operation Write register ‘f’ (dest) Example: MOVSF [05h], REG2 Before Instruction FSR2 = 80h Contents of 85h = 33h REG2 = 11h After Instruction FSR2 = 80h Contents of 85h = 33h REG2 = 33hPIC18F2420/2520/4420/4520 DS39631E-page 312 © 2008 Microchip Technology Inc. MOVSS Move Indexed to Indexed Syntax: MOVSS [zs], [zd] Operands: 0 ≤ zs ≤ 127 0 ≤ zd ≤ 127 Operation: ((FSR2) + zs) → ((FSR2) + zd) Status Affected: None Encoding: 1st word (source) 2nd word (dest.) 1110 1111 1011 xxxx 1zzz xzzz zzzzs zzzzd Description The contents of the source register are moved to the destination register. The addresses of the source and destination registers are determined by adding the 7-bit literal offsets ‘zs’ or ‘zd’, respectively, to the value of FSR2. Both registers can be located anywhere in the 4096-byte data memory space (000h to FFFh). The MOVSS instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an indirect addressing register, the value returned will be 00h. If the resultant destination address points to an indirect addressing register, the instruction will execute as a NOP. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Determine source addr Determine source addr Read source reg Decode Determine dest addr Determine dest addr Write to dest reg Example: MOVSS [05h], [06h] Before Instruction FSR2 = 80h Contents of 85h = 33h Contents of 86h = 11h After Instruction FSR2 = 80h Contents of 85h = 33h Contents of 86h = 33h PUSHL Store Literal at FSR2, Decrement FSR2 Syntax: PUSHL k Operands: 0 ≤ k ≤ 255 Operation: k → (FSR2), FSR2 – 1 → FSR2 Status Affected: None Encoding: 1111 1010 kkkk kkkk Description: The 8-bit literal ‘k’ is written to the data memory address specified by FSR2. FSR2 is decremented by 1 after the operation. This instruction allows users to push values onto a software stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read ‘k’ Process data Write to destination Example: PUSHL 08h Before Instruction FSR2H:FSR2L = 01ECh Memory (01ECh) = 00h After Instruction FSR2H:FSR2L = 01EBh Memory (01ECh) = 08h© 2008 Microchip Technology Inc. DS39631E-page 313 PIC18F2420/2520/4420/4520 SUBFSR Subtract Literal from FSR Syntax: SUBFSR f, k Operands: 0 ≤ k ≤ 63 f ∈ [ 0, 1, 2 ] Operation: FSR(f) – k → FSRf Status Affected: None Encoding: 1110 1001 ffkk kkkk Description: The 6-bit literal ‘k’ is subtracted from the contents of the FSR specified by ‘f’. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: SUBFSR 2, 23h Before Instruction FSR2 = 03FFh After Instruction FSR2 = 03DCh SUBULNK Subtract Literal from FSR2 and Return Syntax: SUBULNK k Operands: 0 ≤ k ≤ 63 Operation: FSR2 – k → FSR2, (TOS) → PC Status Affected: None Encoding: 1110 1001 11kk kkkk Description: The 6-bit literal ‘k’ is subtracted from the contents of the FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. This may be thought of as a special case of the SUBFSR instruction, where f = 3 (binary ‘11’); it operates only on FSR2. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination No Operation No Operation No Operation No Operation Example: SUBULNK 23h Before Instruction FSR2 = 03FFh PC = 0100h After Instruction FSR2 = 03DCh PC = (TOS)PIC18F2420/2520/4420/4520 DS39631E-page 314 © 2008 Microchip Technology Inc. 24.2.3 BYTE-ORIENTED AND BIT-ORIENTED INSTRUCTIONS IN INDEXED LITERAL OFFSET MODE In addition to eight new commands in the extended set, enabling the extended instruction set also enables Indexed Literal Offset Addressing mode (Section 5.5.1 “Indexed Addressing with Literal Offset”). This has a significant impact on the way that many commands of the standard PIC18 instruction set are interpreted. When the extended set is disabled, addresses embedded in opcodes are treated as literal memory locations: either as a location in the Access Bank (‘a’ = 0), or in a GPR bank designated by the BSR (‘a’ = 1). When the extended instruction set is enabled and ‘a’ = 0, however, a file register argument of 5Fh or less is interpreted as an offset from the pointer value in FSR2 and not as a literal address. For practical purposes, this means that all instructions that use the Access RAM bit as an argument – that is, all byte-oriented and bitoriented instructions, or almost half of the core PIC18 instructions – may behave differently when the extended instruction set is enabled. When the content of FSR2 is 00h, the boundaries of the Access RAM are essentially remapped to their original values. This may be useful in creating backward compatible code. If this technique is used, it may be necessary to save the value of FSR2 and restore it when moving back and forth between C and assembly routines in order to preserve the Stack Pointer. Users must also keep in mind the syntax requirements of the extended instruction set (see Section 24.2.3.1 “Extended Instruction Syntax with Standard PIC18 Commands”). Although the Indexed Literal Offset Addressing mode can be very useful for dynamic stack and pointer manipulation, it can also be very annoying if a simple arithmetic operation is carried out on the wrong register. Users who are accustomed to the PIC18 programming must keep in mind that, when the extended instruction set is enabled, register addresses of 5Fh or less are used for Indexed Literal Offset Addressing. Representative examples of typical byte-oriented and bit-oriented instructions in the Indexed Literal Offset Addressing mode are provided on the following page to show how execution is affected. The operand conditions shown in the examples are applicable to all instructions of these types. 24.2.3.1 Extended Instruction Syntax with Standard PIC18 Commands When the extended instruction set is enabled, the file register argument, ‘f’, in the standard byte-oriented and bit-oriented commands is replaced with the literal offset value, ‘k’. As already noted, this occurs only when ‘f’ is less than or equal to 5Fh. When an offset value is used, it must be indicated by square brackets (“[ ]”). As with the extended instructions, the use of brackets indicates to the compiler that the value is to be interpreted as an index or an offset. Omitting the brackets, or using a value greater than 5Fh within brackets, will generate an error in the MPASM Assembler. If the index argument is properly bracketed for Indexed Literal Offset Addressing, the Access RAM argument is never specified; it will automatically be assumed to be ‘0’. This is in contrast to standard operation (extended instruction set disabled) when ‘a’ is set on the basis of the target address. Declaring the Access RAM bit in this mode will also generate an error in the MPASM Assembler. The destination argument, ‘d’, functions as before. In the latest versions of the MPASM assembler, language support for the extended instruction set must be explicitly invoked. This is done with either the command line option, /y, or the PE directive in the source listing. 24.2.4 CONSIDERATIONS WHEN ENABLING THE EXTENDED INSTRUCTION SET It is important to note that the extensions to the instruction set may not be beneficial to all users. In particular, users who are not writing code that uses a software stack may not benefit from using the extensions to the instruction set. Additionally, the Indexed Literal Offset Addressing mode may create issues with legacy applications written to the PIC18 assembler. This is because instructions in the legacy code may attempt to address registers in the Access Bank below 5Fh. Since these addresses are interpreted as literal offsets to FSR2 when the instruction set extension is enabled, the application may read or write to the wrong data addresses. When porting an application to the PIC18F2420/2520/ 4420/4520, it is very important to consider the type of code. A large, re-entrant application that is written in ‘C’ and would benefit from efficient compilation will do well when using the instruction set extensions. Legacy applications that heavily use the Access Bank will most likely not benefit from using the extended instruction set. Note: Enabling the PIC18 instruction set extension may cause legacy applications to behave erratically or fail entirely. © 2008 Microchip Technology Inc. DS39631E-page 315 PIC18F2420/2520/4420/4520 ADDWF ADD W to Indexed (Indexed Literal Offset mode) Syntax: ADDWF [k] {,d} Operands: 0 ≤ k ≤ 95 d ∈ [0,1] Operation: (W) + ((FSR2) + k) → dest Status Affected: N, OV, C, DC, Z Encoding: 0010 01d0 kkkk kkkk Description: The contents of W are added to the contents of the register indicated by FSR2, offset by the value ‘k’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read ‘k’ Process Data Write to destination Example: ADDWF [OFST] , 0 Before Instruction W = 17h OFST = 2Ch FSR2 = 0A00h Contents of 0A2Ch = 20h After Instruction W = 37h Contents of 0A2Ch = 20h BSF Bit Set Indexed (Indexed Literal Offset mode) Syntax: BSF [k], b Operands: 0 ≤ f ≤ 95 0 ≤ b ≤ 7 Operation: 1 → ((FSR2) + k) Status Affected: None Encoding: 1000 bbb0 kkkk kkkk Description: Bit ‘b’ of the register indicated by FSR2, offset by the value ‘k’, is set. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: BSF [FLAG_OFST], 7 Before Instruction FLAG_OFST = 0Ah FSR2 = 0A00h Contents of 0A0Ah = 55h After Instruction Contents of 0A0Ah = D5h SETF Set Indexed (Indexed Literal Offset mode) Syntax: SETF [k] Operands: 0 ≤ k ≤ 95 Operation: FFh → ((FSR2) + k) Status Affected: None Encoding: 0110 1000 kkkk kkkk Description: The contents of the register indicated by FSR2, offset by ‘k’, are set to FFh. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read ‘k’ Process Data Write register Example: SETF [OFST] Before Instruction OFST = 2Ch FSR2 = 0A00h Contents of 0A2Ch = 00h After Instruction Contents of 0A2Ch = FFhPIC18F2420/2520/4420/4520 DS39631E-page 316 © 2008 Microchip Technology Inc. 24.2.5 SPECIAL CONSIDERATIONS WITH MICROCHIP MPLAB® IDE TOOLS The latest versions of Microchip’s software tools have been designed to fully support the extended instruction set of the PIC18F2420/2520/4420/4520 family of devices. This includes the MPLAB C18 C compiler, MPASM assembly language and MPLAB Integrated Development Environment (IDE). When selecting a target device for software development, MPLAB IDE will automatically set default Configuration bits for that device. The default setting for the XINST Configuration bit is ‘0’, disabling the extended instruction set and Indexed Literal Offset Addressing mode. For proper execution of applications developed to take advantage of the extended instruction set, XINST must be set during programming. To develop software for the extended instruction set, the user must enable support for the instructions and the Indexed Addressing mode in their language tool(s). Depending on the environment being used, this may be done in several ways: • A menu option, or dialog box within the environment, that allows the user to configure the language tool and its settings for the project • A command line option • A directive in the source code These options vary between different compilers, assemblers and development environments. Users are encouraged to review the documentation accompanying their development systems for the appropriate information.© 2008 Microchip Technology Inc. DS39631E-page 317 PIC18F2420/2520/4420/4520 25.0 DEVELOPMENT SUPPORT The PIC® microcontrollers are supported with a full range of hardware and software development tools: • Integrated Development Environment - MPLAB® IDE Software • Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C18 and MPLAB C30 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian - MPLAB ASM30 Assembler/Linker/Library • Simulators - MPLAB SIM Software Simulator • Emulators - MPLAB ICE 2000 In-Circuit Emulator - MPLAB REAL ICE™ In-Circuit Emulator • In-Circuit Debugger - MPLAB ICD 2 • Device Programmers - PICSTART® Plus Development Programmer - MPLAB PM3 Device Programmer - PICkit™ 2 Development Programmer • Low-Cost Demonstration and Development Boards and Evaluation Kits 25.1 MPLAB Integrated Development Environment Software The MPLAB IDE software brings an ease of software development previously unseen in the 8/16-bit microcontroller market. The MPLAB IDE is a Windows® operating system-based application that contains: • A single graphical interface to all debugging tools - Simulator - Programmer (sold separately) - Emulator (sold separately) - In-Circuit Debugger (sold separately) • A full-featured editor with color-coded context • A multiple project manager • Customizable data windows with direct edit of contents • High-level source code debugging • Visual device initializer for easy register initialization • Mouse over variable inspection • Drag and drop variables from source to watch windows • Extensive on-line help • Integration of select third party tools, such as HI-TECH Software C Compilers and IAR C Compilers The MPLAB IDE allows you to: • Edit your source files (either assembly or C) • One touch assemble (or compile) and download to PIC MCU emulator and simulator tools (automatically updates all project information) • Debug using: - Source files (assembly or C) - Mixed assembly and C - Machine code MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increased flexibility and power.PIC18F2420/2520/4420/4520 DS39631E-page 318 © 2008 Microchip Technology Inc. 25.2 MPASM Assembler The MPASM Assembler is a full-featured, universal macro assembler for all PIC MCUs. The MPASM Assembler generates relocatable object files for the MPLINK Object Linker, Intel® standard HEX files, MAP files to detail memory usage and symbol reference, absolute LST files that contain source lines and generated machine code and COFF files for debugging. The MPASM Assembler features include: • Integration into MPLAB IDE projects • User-defined macros to streamline assembly code • Conditional assembly for multi-purpose source files • Directives that allow complete control over the assembly process 25.3 MPLAB C18 and MPLAB C30 C Compilers The MPLAB C18 and MPLAB C30 Code Development Systems are complete ANSI C compilers for Microchip’s PIC18 and PIC24 families of microcontrollers and the dsPIC30 and dsPIC33 family of digital signal controllers. These compilers provide powerful integration capabilities, superior code optimization and ease of use not found with other compilers. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. 25.4 MPLINK Object Linker/ MPLIB Object Librarian The MPLINK Object Linker combines relocatable objects created by the MPASM Assembler and the MPLAB C18 C Compiler. It can link relocatable objects from precompiled libraries, using directives from a linker script. The MPLIB Object Librarian manages the creation and modification of library files of precompiled code. When a routine from a library is called from a source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The object linker/library features include: • Efficient linking of single libraries instead of many smaller files • Enhanced code maintainability by grouping related modules together • Flexible creation of libraries with easy module listing, replacement, deletion and extraction 25.5 MPLAB ASM30 Assembler, Linker and Librarian MPLAB ASM30 Assembler produces relocatable machine code from symbolic assembly language for dsPIC30F devices. MPLAB C30 C Compiler uses the assembler to produce its object file. The assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. Notable features of the assembler include: • Support for the entire dsPIC30F instruction set • Support for fixed-point and floating-point data • Command line interface • Rich directive set • Flexible macro language • MPLAB IDE compatibility 25.6 MPLAB SIM Software Simulator The MPLAB SIM Software Simulator allows code development in a PC-hosted environment by simulating the PIC MCUs and dsPIC® DSCs on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a comprehensive stimulus controller. Registers can be logged to files for further run-time analysis. The trace buffer and logic analyzer display extend the power of the simulator to record and track program execution, actions on I/O, most peripherals and internal registers. The MPLAB SIM Software Simulator fully supports symbolic debugging using the MPLAB C18 and MPLAB C30 C Compilers, and the MPASM and MPLAB ASM30 Assemblers. The software simulator offers the flexibility to develop and debug code outside of the hardware laboratory environment, making it an excellent, economical software development tool. © 2008 Microchip Technology Inc. DS39631E-page 319 PIC18F2420/2520/4420/4520 25.7 MPLAB ICE 2000 High-Performance In-Circuit Emulator The MPLAB ICE 2000 In-Circuit Emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PIC microcontrollers. Software control of the MPLAB ICE 2000 In-Circuit Emulator is advanced by the MPLAB Integrated Development Environment, which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The architecture of the MPLAB ICE 2000 In-Circuit Emulator allows expansion to support new PIC microcontrollers. The MPLAB ICE 2000 In-Circuit Emulator system has been designed as a real-time emulation system with advanced features that are typically found on more expensive development tools. The PC platform and Microsoft® Windows® 32-bit operating system were chosen to best make these features available in a simple, unified application. 25.8 MPLAB REAL ICE In-Circuit Emulator System MPLAB REAL ICE In-Circuit Emulator System is Microchip’s next generation high-speed emulator for Microchip Flash DSC and MCU devices. It debugs and programs PIC® Flash MCUs and dsPIC® Flash DSCs with the easy-to-use, powerful graphical user interface of the MPLAB Integrated Development Environment (IDE), included with each kit. The MPLAB REAL ICE probe is connected to the design engineer’s PC using a high-speed USB 2.0 interface and is connected to the target with either a connector compatible with the popular MPLAB ICD 2 system (RJ11) or with the new high-speed, noise tolerant, LowVoltage Differential Signal (LVDS) interconnection (CAT5). MPLAB REAL ICE is field upgradeable through future firmware downloads in MPLAB IDE. In upcoming releases of MPLAB IDE, new devices will be supported, and new features will be added, such as software breakpoints and assembly code trace. MPLAB REAL ICE offers significant advantages over competitive emulators including low-cost, full-speed emulation, real-time variable watches, trace analysis, complex breakpoints, a ruggedized probe interface and long (up to three meters) interconnection cables. 25.9 MPLAB ICD 2 In-Circuit Debugger Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a powerful, low-cost, run-time development tool, connecting to the host PC via an RS-232 or high-speed USB interface. This tool is based on the Flash PIC MCUs and can be used to develop for these and other PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes the in-circuit debugging capability built into the Flash devices. This feature, along with Microchip’s In-Circuit Serial ProgrammingTM (ICSPTM) protocol, offers costeffective, in-circuit Flash debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by setting breakpoints, single stepping and watching variables, and CPU status and peripheral registers. Running at full speed enables testing hardware and applications in real time. MPLAB ICD 2 also serves as a development programmer for selected PIC devices. 25.10 MPLAB PM3 Device Programmer The MPLAB PM3 Device Programmer is a universal, CE compliant device programmer with programmable voltage verification at VDDMIN and VDDMAX for maximum reliability. It features a large LCD display (128 x 64) for menus and error messages and a modular, detachable socket assembly to support various package types. The ICSP™ cable assembly is included as a standard item. In Stand-Alone mode, the MPLAB PM3 Device Programmer can read, verify and program PIC devices without a PC connection. It can also set code protection in this mode. The MPLAB PM3 connects to the host PC via an RS-232 or USB cable. The MPLAB PM3 has high-speed communications and optimized algorithms for quick programming of large memory devices and incorporates an SD/MMC card for file storage and secure data applications.PIC18F2420/2520/4420/4520 DS39631E-page 320 © 2008 Microchip Technology Inc. 25.11 PICSTART Plus Development Programmer The PICSTART Plus Development Programmer is an easy-to-use, low-cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus Development Programmer supports most PIC devices in DIP packages up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus Development Programmer is CE compliant. 25.12 PICkit 2 Development Programmer The PICkit™ 2 Development Programmer is a low-cost programmer and selected Flash device debugger with an easy-to-use interface for programming many of Microchip’s baseline, mid-range and PIC18F families of Flash memory microcontrollers. The PICkit 2 Starter Kit includes a prototyping development board, twelve sequential lessons, software and HI-TECH’s PICC™ Lite C compiler, and is designed to help get up to speed quickly using PIC® microcontrollers. The kit provides everything needed to program, evaluate and develop applications using Microchip’s powerful, mid-range Flash memory family of microcontrollers. 25.13 Demonstration, Development and Evaluation Boards A wide variety of demonstration, development and evaluation boards for various PIC MCUs and dsPIC DSCs allows quick application development on fully functional systems. Most boards include prototyping areas for adding custom circuitry and provide application firmware and source code for examination and modification. The boards support a variety of features, including LEDs, temperature sensors, switches, speakers, RS-232 interfaces, LCD displays, potentiometers and additional EEPROM memory. The demonstration and development boards can be used in teaching environments, for prototyping custom circuits and for learning about various microcontroller applications. In addition to the PICDEM™ and dsPICDEM™ demonstration/development board series of circuits, Microchip has a line of evaluation kits and demonstration software for analog filter design, KEELOQ® security ICs, CAN, IrDA®, PowerSmart battery management, SEEVAL® evaluation system, Sigma-Delta ADC, flow rate sensing, plus many more. Check the Microchip web page (www.microchip.com) for the complete list of demonstration, development and evaluation kits.© 2008 Microchip Technology Inc. DS39631E-page 321 PIC18F2420/2520/4420/4520 26.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings(†) Ambient temperature under bias.............................................................................................................-40°C to +125°C Storage temperature .............................................................................................................................. -65°C to +150°C Voltage on any pin with respect to VSS (except VDD and MCLR) ................................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. ±20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk by all ports .......................................................................................................................200 mA Maximum current sourced by all ports ..................................................................................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD – ∑ IOH} + ∑ {(VDD – VOH) x IOH} + ∑(VOL x IOL) 2: Voltage spikes below VSS at the MCLR/VPP/RE3 pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/VPP/ RE3 pin, rather than pulling this pin directly to VSS. † NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.PIC18F2420/2520/4420/4520 DS39631E-page 322 © 2008 Microchip Technology Inc. FIGURE 26-1: PIC18F2420/2520/4420/4520 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL) FIGURE 26-2: PIC18F2420/2520/4420/4520 VOLTAGE-FREQUENCY GRAPH (EXTENDED) Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 40 MHz 5.0V 3.5V 3.0V 2.5V 4.2V PIC18F2420/2520/4420/4520 Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 25 MHz 5.0V 3.5V 3.0V 2.5V 4.2V PIC18F2420/2520/4420/4520© 2008 Microchip Technology Inc. DS39631E-page 323 PIC18F2420/2520/4420/4520 FIGURE 26-3: PIC18LF2420/2520/4420/4520 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL) Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 40 MHz 5.0V 3.5V 3.0V 2.5V FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz Note: VDDAPPMIN is the minimum voltage of the PIC® device in the application. 4 MHz 4.2V PIC18LF2420/2520/4420/4520PIC18F2420/2520/4420/4520 DS39631E-page 324 © 2008 Microchip Technology Inc. 26.1 DC Characteristics: Supply Voltage PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions D001 VDD Supply Voltage PIC18LF2X2X/4X20 2.0 — 5.5 V HS, XT, RC and LP Oscillator mode PIC18F2X20/4X20 4.2 — 5.5 V D002 VDR RAM Data Retention Voltage(1) 1.5 — — V D003 VPOR VDD Start Voltage to Ensure Internal Power-on Reset Signal — — 0.7 V See section on Power-on Reset for details D004 SVDD VDD Rise Rate to Ensure Internal Power-on Reset Signal 0.05 — — V/ms See section on Power-on Reset for details VBOR Brown-out Reset Voltage D005 PIC18LF2X2X/4X20 BORV<1:0> = 11 2.00 2.11 2.22 V BORV<1:0> = 10 2.65 2.79 2.93 V D005 All Devices BORV<1:0> = 01(2) 4.11 4.33 4.55 V BORV<1:0> = 00 4.36 4.59 4.82 V Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data. 2: With BOR enabled, full-speed operation (FOSC = 40 MHz) is supported until a BOR occurs. This is valid although VDD may be below the minimum voltage for this frequency.© 2008 Microchip Technology Inc. DS39631E-page 325 PIC18F2420/2520/4420/4520 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Power-Down Current (IPD) (1) PIC18LF2X2X/4X20 0.1 0.5 μA -40°C VDD = 2.0V (Sleep mode) 0.1 0.5 μA +25°C 0.2 2.5 μA +85°C PIC18LF2X2X/4X20 0.1 0.7 μA -40°C VDD = 3.0V (Sleep mode) 0.1 0.7 μA +25°C 0.3 3.5 μA +85°C All devices 0.1 1.0 μA -40°C VDD = 5.0V (Sleep mode) 0.2 1.0 μA +25°C 0.7 10 μA +85°C Extended devices only 10 100 μA +125°C Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.PIC18F2420/2520/4420/4520 DS39631E-page 326 © 2008 Microchip Technology Inc. Supply Current (IDD) (2) PIC18LF2X2X/4X20 13 25 μA -40°C VDD = 2.0V FOSC = 31 kHz (RC_RUN mode, INTRC source) 13 22 μA +25°C 14 25 μA +85°C PIC18LF2X2X/4X20 42 61 μA -40°C 34 46 μA +25°C VDD = 3.0V 28 45 μA +85°C All devices 103 160 μA -40°C VDD = 5.0V 82 130 μA +25°C 67 120 μA +85°C Extended devices only 71 230 μA +125°C PIC18LF2X2X/4X20 320 440 μA -40°C VDD = 2.0V FOSC = 1 MHz (RC_RUN mode, INTOSC source) 330 440 μA +25°C 330 440 μA +85°C PIC18LF2X2X/4X20 630 800 μA -40°C 590 720 μA +25°C VDD = 3.0V 570 700 μA +85°C All devices 1.2 1.6 mA -40°C VDD = 5.0V 1.0 1.5 mA +25°C 1.0 1.5 mA +85°C Extended devices only 1.0 1.5 mA +125°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.© 2008 Microchip Technology Inc. DS39631E-page 327 PIC18F2420/2520/4420/4520 Supply Current (IDD) (2) PIC18LF2X2X/4X20 0.8 1.1 mA -40°C VDD = 2.0V FOSC = 4 MHz (RC_RUN mode, INTOSC source) 0.8 1.1 mA +25°C 0.8 1.1 mA +85°C PIC18LF2X2X/4X20 1.3 1.7 mA -40°C 1.3 1.7 mA +25°C VDD = 3.0V 1.3 1.7 mA +85°C All devices 2.5 3.5 mA -40°C VDD = 5.0V 2.5 3.5 mA +25°C 2.5 3.5 mA +85°C Extended devices only 2.5 3.5 mA +125°C PIC18LF2X2X/4X20 2.9 5 μA -40°C VDD = 2.0V FOSC = 31 kHz (RC_IDLE mode, INTRC source) 3.1 5 μA +25°C 3.6 9.5 μA +85°C PIC18LF2X2X/4X20 4.5 8 μA -40°C 4.8 8 μA +25°C VDD = 3.0V 5.8 15 μA +85°C All devices 9.2 16 μA -40°C VDD = 5.0V 9.8 16 μA +25°C 11.0 35 μA +85°C Extended devices only 21 160 μA +125°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.PIC18F2420/2520/4420/4520 DS39631E-page 328 © 2008 Microchip Technology Inc. Supply Current (IDD) (2) PIC18LF2X2X/4X20 165 250 μA -40°C VDD = 2.0V FOSC = 1 MHz (RC_IDLE mode, INTOSC source) 175 250 μA +25°C 190 270 μA +85°C PIC18LF2X2X/4X20 250 360 μA -40°C 270 360 μA +25°C VDD = 3.0V 290 380 μA +85°C All devices 500 700 μA -40°C VDD = 5.0V 520 700 μA +25°C 550 700 μA +85°C Extended devices only 0.6 1 mA +125°C PIC18LF2X2X/4X20 340 500 μA -40°C VDD = 2.0V FOSC = 4 MHz (RC_IDLE mode, INTOSC source) 350 500 μA +25°C 360 500 μA +85°C PIC18LF2X2X/4X20 520 800 μA -40°C 540 800 μA +25°C VDD = 3.0V 580 850 μA +85°C All devices 1.0 1.6 mA -40°C VDD = 5.0V 1.1 1.4 mA +25°C 1.1 1.4 mA +85°C Extended devices only 1.1 2.0 mA +125°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.© 2008 Microchip Technology Inc. DS39631E-page 329 PIC18F2420/2520/4420/4520 Supply Current (IDD) (2) PIC18LF2X2X/4X20 250 350 μA -40°C VDD = 2.0V FOSC = 1 MHZ (PRI_RUN, EC oscillator) 260 350 μA +25°C 250 350 μA +85°C PIC18LF2X2X/4X20 550 650 μA -40°C 480 640 μA +25°C VDD = 3.0V 460 600 μA +85°C All devices 1.2 1.5 mA -40°C VDD = 5.0V 1.1 1.4 mA +25°C 1.0 1.3 mA +85°C Extended devices only 1.0 3.0 mA +125°C PIC18LF2X2X/4X20 0.72 1.0 mA -40°C VDD = 2.0V FOSC = 4 MHz (PRI_RUN, EC oscillator) 0.74 1.0 mA +25°C 0.74 1.0 mA +85°C PIC18LF2X2X/4X20 1.3 1.8 mA -40°C 1.3 1.8 mA +25°C VDD = 3.0V 1.3 1.8 mA +85°C All devices 2.7 4.0 mA -40°C VDD = 5.0V 2.6 4.0 mA +25°C 2.5 4.0 mA +85°C Extended devices only 2.6 5.0 mA +125°C Extended devices only 8.4 13 mA +125°C VDD = 4.2V FOSC = 25 MHz (PRI_RUN, EC oscillator) 11 16 mA +125°C VDD = 5.0V All devices 15 20 mA -40°C VDD = 4.2V FOSC = 40 MHZ (PRI_RUN, EC oscillator) 15 20 mA +25°C 15 20 mA +85°C All devices 20 25 mA -40°C 20 25 mA +25°C VDD = 5.0V 20 25 mA +85°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.PIC18F2420/2520/4420/4520 DS39631E-page 330 © 2008 Microchip Technology Inc. Supply Current (IDD) (2) All devices 7.5 10 mA -40°C VDD = 4.2V FOSC = 4 MHZ, 16 MHz internal (PRI_RUN HS+PLL) 7.4 10 mA +25°C 7.3 10 mA +85°C Extended devices only 8.0 12 mA +125°C All devices 10 12 mA -40°C VDD = 5.0V FOSC = 4 MHZ, 16 MHz internal (PRI_RUN HS+PLL) 10 12 mA +25°C 9.7 12 mA +85°C Extended devices only 10 14 mA +125°C All devices 15 20 mA -40°C VDD = 4.2V FOSC = 10 MHZ, 40 MHz internal (PRI_RUN HS+PLL) 15 20 mA +25°C 15 20 mA +85°C All devices 20 25 mA -40°C VDD = 5.0V FOSC = 10 MHZ, 40 MHz internal (PRI_RUN HS+PLL) 20 25 mA +25°C 20 25 mA +85°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.© 2008 Microchip Technology Inc. DS39631E-page 331 PIC18F2420/2520/4420/4520 Supply Current (IDD) (2) PIC18LF2X2X/4X20 65 100 μA -40°C VDD = 2.0V FOSC = 1 MHz (PRI_IDLE mode, EC oscillator) 65 100 μA +25°C 70 110 μA +85°C PIC18LF2X2X/4X20 120 140 μA -40°C 120 140 μA +25°C VDD = 3.0V 130 160 μA +85°C All devices 230 300 μA -40°C VDD = 5.0V 235 300 μA +25°C 240 300 μA +85°C Extended devices only 260 500 μA +125°C PIC18LF2X2X/4X20 260 360 μA -40°C VDD = 2.0V FOSC = 4 MHz (PRI_IDLE mode, EC oscillator) 255 360 μA +25°C 270 360 μA +85°C PIC18LF2X2X/4X20 420 620 μA -40°C 430 620 μA +25°C VDD = 3.0V 450 650 μA +85°C All devices 0.9 1.2 mA -40°C VDD = 5.0V 0.9 1.2 mA +25°C 0.9 1.2 mA +85°C Extended devices only 1 1.3 mA +125°C Extended devices only 2.8 6.0 mA +125°C VDD = 4.2V FOSC = 25 MHz (PRI_IDLE mode, EC oscillator) 4.3 8.0 mA +125°C VDD = 5.0V All devices 6.0 10 mA -40°C VDD = 4.2V FOSC = 40 MHz (PRI_IDLE mode, EC oscillator) 6.2 10 mA +25°C 6.6 10 mA +85°C All devices 8.1 13 mA -40°C 9.1 12 mA +25°C VDD = 5.0V 8.3 12 mA +85°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.PIC18F2420/2520/4420/4520 DS39631E-page 332 © 2008 Microchip Technology Inc. Supply Current (IDD) (2) PIC18LF2X2X/4X20 10 25 μA -40°C(3) VDD = 2.0V FOSC = 32 kHz(3) (SEC_RUN mode, Timer1 as clock) 11 21 μA +25°C 12 25 μA +85°C PIC18LF2X2X/4X20 42 57 μA -40°C(3) 33 45 μA +25°C VDD = 3.0V 29 45 μA +85°C All devices 105 150 μA -40°C(3) 81 130 μA +25°C VDD = 5.0V 67 130 μA +85°C PIC18LF2X2X/4X20 3.0 12 μA -40°C(3) VDD = 2.0V FOSC = 32 kHz(3) (SEC_IDLE mode, Timer1 as clock) 3.0 6 μA +25°C 3.7 10 μA +85°C PIC18LF2X2X/4X20 5.0 15 μA -40°C(3) 5.4 10 μA +25°C VDD = 3.0V 6.3 15 μA +85°C All devices 8.5 25 μA -40°C(3) 9.0 20 μA +25°C VDD = 5.0V 10.5 30 μA +85°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.© 2008 Microchip Technology Inc. DS39631E-page 333 PIC18F2420/2520/4420/4520 Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔIOSCB, ΔIAD) D026 (ΔIAD) A/D Converter 0.2 1.0 μA -40°C to +85°C VDD = 2.0V A/D on, not converting 0.2 1.0 μA -40°C to +85°C VDD = 3.0V 0.2 1.0 μA -40°C to +85°C VDD = 5.0V 0.5 4.0 μA -40°C to +125°C D022 (ΔIWDT) Watchdog Timer 1.3 2.2 μA -40°C 1.4 2.2 μA +25°C VDD = 2.0V 1.6 2.3 μA +85°C 1.9 3.5 μA -40°C 2.0 3.5 μA +25°C VDD = 3.0V 2.2 3.5 μA +85°C 3.0 7.5 μA -40°C VDD = 5.0V 3.5 7.5 μA +25°C 3.5 7.8 μA +85°C 4.0 10 μA +125°C D022A (ΔIBOR) Brown-out Reset(4) 35 50 μA -40°C to +85°C VDD = 3.0V 40 55 μA -40°C to +85°C VDD = 5.0V 55 65 μA -40°C to +125°C 0 2 μA -40°C to +85°C Sleep mode, 0 5 μA -40°C to +125°C BOREN<1:0> = 10 D022B (ΔILVD) High/Low-Voltage Detect(4) 22 38 μA -40°C to +85°C VDD = 2.0V 25 40 μA -40°C to +85°C VDD = 3.0V 29 45 μA -40°C to +85°C VDD = 5.0V 30 45 μA -40°C to +125°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.PIC18F2420/2520/4420/4520 DS39631E-page 334 © 2008 Microchip Technology Inc. D025L (ΔIOSCB) Timer1 Oscillator 4.5 9.0 μA -40°C(3) VDD = 2.0V 32 kHz on Timer1 0.9 1.6 μA -10°C 0.9 1.6 μA +25°C 0.9 1.8 μA +85°C 4.8 10 μA -40°C(3) VDD = 3.0V 32 kHz on Timer1 1.0 2.0 μA -10°C 1.0 2.0 μA +25°C 1.0 2.6 μA +85°C 6.0 11 μA -40°C(3) VDD = 5.0V 32 kHz on Timer1 1.6 4.0 μA -10°C 1.6 4.0 μA +25°C 1.6 4.0 μA +85°C 26.2 DC Characteristics: Power-Down and Supply Current PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Device Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). 2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. 3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When operation will always be above -10°C, then the low-power Timer1 oscillator may be selected. 4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.© 2008 Microchip Technology Inc. DS39631E-page 335 PIC18F2420/2520/4420/4520 26.3 DC Characteristics: PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Param No. Symbol Characteristic Min Max Units Conditions VIL Input Low Voltage I/O Ports: D030 with TTL Buffer VSS 0.15 VDD V VDD < 4.5V D030A — 0.8 V 4.5V ≤ VDD ≤ 5.5V D031 with Schmitt Trigger Buffer VSS 0.2 VDD V D031A RC3 and RC4 VSS 0.3 VDD V I2C™ enabled D031B VSS 0.8 V SMBus enabled D032 MCLR VSS 0.2 VDD V D033 OSC1 VSS 0.3 VDD V HS, HSPLL modes D033A D033B D034 OSC1 OSC1 T13CKI VSS VSS VSS 0.2 VDD 0.3 0.3 V V V RC, EC modes(1) XT, LP modes VIH Input High Voltage I/O Ports: D040 with TTL Buffer 0.25 VDD + 0.8V VDD V VDD < 4.5V D040A 2.0 VDD V 4.5V ≤ VDD ≤ 5.5V D041 with Schmitt Trigger Buffer 0.8 VDD VDD V D041A RC3 and RC4 0.7 VDD VDD V I2C enabled D041B 2.1 VDD V SMBus enabled D042 MCLR 0.8 VDD VDD V D043 OSC1 0.7 VDD VDD V HS, HSPLL modes D043A D043B D043C D044 OSC1 OSC1 OSC1 T13CKI 0.8 VDD 0.9 VDD 1.6 1.6 VDD VDD VDD VDD V V V V EC mode RC mode(1) XT, LP modes IIL Input Leakage Current(2,3) D060 I/O Ports — ±200 ±50 nA nA VDD < 5.5V, VSS ≤ VPIN ≤ VDD, Pin at high-impedance VDD < 3V, VSS ≤ VPIN ≤ VDD, Pin at high-impedance D061 MCLR — ±1 μA Vss ≤ VPIN ≤ VDD D063 OSC1 — ±1 μA Vss ≤ VPIN ≤ VDD IPU Weak Pull-up Current D070 IPURB PORTB Weak Pull-up Current 50 400 μA VDD = 5V, VPIN = VSS Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC® device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin.PIC18F2420/2520/4420/4520 DS39631E-page 336 © 2008 Microchip Technology Inc. VOL Output Low Voltage D080 I/O Ports — 0.6 V IOL = 8.5 mA, VDD = 4.5V, -40°C to +85°C D083 OSC2/CLKO (RC, RCIO, EC, ECIO modes) — 0.6 V IOL = 1.6 mA, VDD = 4.5V, -40°C to +85°C VOH Output High Voltage(3) D090 I/O Ports VDD – 0.7 — V IOH = -3.0 mA, VDD = 4.5V, -40°C to +85°C D092 OSC2/CLKO (RC, RCIO, EC, ECIO modes) VDD – 0.7 — V IOH = -1.3 mA, VDD = 4.5V, -40°C to +85°C Capacitive Loading Specs on Output Pins D100 COSC2 OSC2 pin — 15 pF In XT, HS and LP modes when external clock is used to drive OSC1 D101 CIO All I/O pins and OSC2 (in RC mode) — 50 pF To meet the AC Timing Specifications D102 CB SCL, SDA — 400 pF I2C™ Specification 26.3 DC Characteristics: PIC18F2420/2520/4420/4520 (Industrial) PIC18LF2420/2520/4420/4520 (Industrial) (Continued) DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Param No. Symbol Characteristic Min Max Units Conditions Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC® device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin.© 2008 Microchip Technology Inc. DS39631E-page 337 PIC18F2420/2520/4420/4520 TABLE 26-1: MEMORY PROGRAMMING REQUIREMENTS DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Param No. Sym Characteristic Min Typ† Max Units Conditions Data EEPROM Memory D120 ED Byte Endurance 100K 1M — E/W -40°C to +85°C D121 VDRW VDD for Read/Write VMIN — 5.5 V Using EECON to read/write VMIN = Minimum operating voltage D122 TDEW Erase/Write Cycle Time — 4 — ms D123 TRETD Characteristic Retention 40 — — Year Provided no other specifications are violated D124 TREF Number of Total Erase/Write Cycles before Refresh(1) 1M 10M — E/W -40°C to +85°C D125 IDDP Supply Current during Programming — 10 — mA Program Flash Memory D130 EP Cell Endurance 10K 100K — E/W -40°C to +85°C D131 VPR VDD for Read VMIN — 5.5 V VMIN = Minimum operating voltage D132 VIE VDD for Block Erase 3.0 — 5.5 V Using ICSP™ port, +25°C D132A VIW VDD for Externally Timed Erase or Write 4.5 — 5.5 V Using ICSP™ port, +25°C D132B VPEW VDD for Self-Timed Write VMIN — 5.5 V VMIN = Minimum operating voltage D133 TIE ICSP Block Erase Cycle Time — 4 — ms VDD ≥ 4.5V D133A TIW ICSP Erase or Write Cycle Time (externally timed) 1 — — ms VDD ≥ 4.5V, +25°C D133A TIW Self-Timed Write Cycle Time — 2 — ms D134 TRETD Characteristic Retention 40 100 — Year Provided no other specifications are violated D135 IDDP Supply Current during Programming — 10 — mA † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Refer to Section 7.8 “Using the Data EEPROM” for a more detailed discussion on data EEPROM endurance.PIC18F2420/2520/4420/4520 DS39631E-page 338 © 2008 Microchip Technology Inc. TABLE 26-2: COMPARATOR SPECIFICATIONS TABLE 26-3: VOLTAGE REFERENCE SPECIFICATIONS Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated). Param No. Sym Characteristics Min Typ Max Units Comments D300 VIOFF Input Offset Voltage — ±5.0 ±10 mV D301 VICM Input Common Mode Voltage 0 — VDD – 1.5 V D302 CMRR Common Mode Rejection Ratio 55 — — dB 300 TRESP Response Time(1) — 150 400 ns PIC18FXXXX 300A — 150 600 ns PIC18LFXXXX, VDD = 2.0V 301 TMC2OV Comparator Mode Change to Output Valid — — 10 μs Note 1: Response time measured with one comparator input at (VDD – 1.5)/2, while the other input transitions from VSS to VDD. Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated). Param No. Sym Characteristics Min Typ Max Units Comments D310 VRES Resolution VDD/24 — VDD/32 LSb D311 VRAA Absolute Accuracy — — 1/2 LSb D312 VRUR Unit Resistor Value (R) — 2k — Ω 310 TSET Settling Time(1) — — 10 μs Note 1: Settling time measured while CVRR = 1 and CVR3:CVR0 transitions from ‘0000’ to ‘1111’.© 2008 Microchip Technology Inc. DS39631E-page 339 PIC18F2420/2520/4420/4520 FIGURE 26-4: HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS TABLE 26-4: HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Param No. Sym Characteristic Min Typ Max Units Conditions D420 HLVD Voltage on VDD Transition High-to-Low HLVDL<3:0> = 0000 2.06 2.17 2.28 V HLVDL<3:0> = 0001 2.12 2.23 2.34 V HLVDL<3:0> = 0010 2.24 2.36 2.48 V HLVDL<3:0> = 0011 2.32 2.44 2.56 V HLVDL<3:0> = 0100 2.47 2.60 2.73 V HLVDL<3:0> = 0101 2.65 2.79 2.93 V HLVDL<3:0> = 0110 2.74 2.89 3.04 V HLVDL<3:0> = 0111 2.96 3.12 3.28 V HLVDL<3:0> = 1000 3.22 3.39 3.56 V HLVDL<3:0> = 1001 3.37 3.55 3.73 V HLVDL<3:0> = 1010 3.52 3.71 3.90 V HLVDL<3:0> = 1011 3.70 3.90 4.10 V HLVDL<3:0> = 1100 3.90 4.11 4.32 V HLVDL<3:0> = 1101 4.11 4.33 4.55 V HLVDL<3:0> = 1110 4.36 4.59 4.82 V VLVD HLVDIF(1) VDD (HLVDIF set by hardware) (HLVDIF can be cleared in software) Note 1: VDIRMAG = 0.PIC18F2420/2520/4420/4520 DS39631E-page 340 © 2008 Microchip Technology Inc. 26.4 AC (Timing) Characteristics 26.4.1 TIMING PARAMETER SYMBOLOGY The timing parameter symbols have been created using one of the following formats: 1. TppS2ppS 3. TCC:ST (I2C specifications only) 2. TppS 4. Ts (I2C specifications only) T F Frequency T Time Lowercase letters (pp) and their meanings: pp cc CCP1 osc OSC1 ck CLKO rd RD cs CS rw RD or WR di SDI sc SCK do SDO ss SS dt Data in t0 T0CKI io I/O port t1 T13CKI mc MCLR wr WR Uppercase letters and their meanings: S F Fall P Period H High R Rise I Invalid (High-impedance) V Valid L Low Z High-impedance I 2C only AA output access High High BUF Bus free Low Low TCC:ST (I2C specifications only) CC HD Hold SU Setup ST DAT DATA input hold STO Stop condition STA Start condition© 2008 Microchip Technology Inc. DS39631E-page 341 PIC18F2420/2520/4420/4520 26.4.2 TIMING CONDITIONS The temperature and voltages specified in Table 26-5 apply to all timing specifications unless otherwise noted. Figure 26-5 specifies the load conditions for the timing specifications. TABLE 26-5: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC FIGURE 26-5: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS Note: Because of space limitations, the generic terms “PIC18FXXXX” and “PIC18LFXXXX” are used throughout this section to refer to the PIC18F2420/2520/4420/4520 and PIC18LF2420/2520/4420/4520 families of devices specifically and only those devices. AC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Operating voltage VDD range as described in DC specification Section 26.1 and Section 26.3. LF parts operate for industrial temperatures only. VDD/2 CL RL Pin Pin VSS VSS CL RL = 464Ω CL = 50 pF for all pins except OSC2/CLKO and including D and E outputs as ports Load Condition 1 Load Condition 2PIC18F2420/2520/4420/4520 DS39631E-page 342 © 2008 Microchip Technology Inc. 26.4.3 TIMING DIAGRAMS AND SPECIFICATIONS FIGURE 26-6: EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL) TABLE 26-6: EXTERNAL CLOCK TIMING REQUIREMENTS Param. No. Symbol Characteristic Min Max Units Conditions 1A FOSC External CLKI Frequency(1) DC 1 MHz XT, RC Oscillator mode DC 25 MHz HS Oscillator mode DC 31.25 kHz LP Oscillator mode DC 40 MHz EC Oscillator mode Oscillator Frequency(1) DC 4 MHz RC Oscillator mode 0.1 4 MHz XT Oscillator mode 4 25 MHz HS Oscillator mode 4 10 MHz HS + PLL Oscillator mode 5 200 kHz LP Oscillator mode 1 TOSC External CLKI Period(1) 1000 — ns XT, RC Oscillator mode 40 — ns HS Oscillator mode 32 — μs LP Oscillator mode 25 — ns EC Oscillator mode Oscillator Period(1) 250 — ns RC Oscillator mode 0.25 10 μs XT Oscillator mode 40 250 ns HS Oscillator mode 100 250 ns HS + PLL Oscillator mode 5 200 μs LP Oscillator mode 2 TCY Instruction Cycle Time(1) 100 — ns TCY = 4/FOSC, Industrial 160 — ns TCY = 4/FOSC, Extended 3 TOSL, TOSH External Clock in (OSC1) High or Low Time 30 — ns XT Oscillator mode 2.5 — μs LP Oscillator mode 10 — ns HS Oscillator mode 4 TOSR, TOSF External Clock in (OSC1) Rise or Fall Time — 20 ns XT Oscillator mode — 50 ns LP Oscillator mode — 7.5 ns HS Oscillator mode Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations except PLL. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the “max.” cycle time limit is “DC” (no clock) for all devices. OSC1 CLKO Q4 Q1 Q2 Q3 Q4 Q1 1 2 3 3 4 4© 2008 Microchip Technology Inc. DS39631E-page 343 PIC18F2420/2520/4420/4520 TABLE 26-7: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2V TO 5.5V) TABLE 26-8: AC CHARACTERISTICS: INTERNAL RC ACCURACY PIC18F2420/2520/4420/4520 (INDUSTRIAL) PIC18LF2420/2520/4420/4520 (INDUSTRIAL) Param No. Sym Characteristic Min Typ† Max Units Conditions F10 FOSC Oscillator Frequency Range 4 — 10 MHz HS mode only F11 FSYS On-Chip VCO System Frequency 16 — 40 MHz HS mode only F12 trc PLL Start-up Time (Lock Time) — — 2 ms F13 ΔCLK CLKO Stability (Jitter) -2 — +2 % † Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. PIC18LF2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18F2420/2520/4420/4520 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial Param No. Device Min Typ Max Units Conditions INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz, 31 kHz(1) PIC18LF2420/2520/4420/4520 -2 +/-1 2 % +25°C VDD = 2.7-3.3V -5 +/-1 5 % -40°C to +85°C VDD = 2.7-3.3V PIC18F2420/2520/4420/4520 -2 +/-1 2 % +25°C VDD = 4.5-5.5V -5 +/-1 5 % -40°C to +85°C VDD = 4.5-5.5V INTRC Accuracy @ Freq = 31 kHz PIC18LF2420/2520/4420/4520 26.562 — 35.938 kHz -40°C to +85°C VDD = 2.7-3.3V PIC18F2420/2520/4420/4520 26.562 — 35.938 kHz -40°C to +85°C VDD = 4.5-5.5V Legend: Shading of rows is to assist in readability of the table. Note 1: Frequency calibrated at 25°C. OSCTUNE register can be used to compensate for temperature drift.PIC18F2420/2520/4420/4520 DS39631E-page 344 © 2008 Microchip Technology Inc. FIGURE 26-7: CLKO AND I/O TIMING TABLE 26-9: CLKO AND I/O TIMING REQUIREMENTS Param No. Symbol Characteristic Min Typ Max Units Conditions 10 TosH2ckL OSC1 ↑ to CLKO ↓ — 75 200 ns (Note 1) 11 TosH2ckH OSC1 ↑ to CLKO ↑ — 75 200 ns (Note 1) 12 TckR CLKO Rise Time — 35 100 ns (Note 1) 13 TckF CLKO Fall Time — 35 100 ns (Note 1) 14 TckL2ioV CLKO ↓ to Port Out Valid — — 0.5 TCY + 20 ns (Note 1) 15 TioV2ckH Port In Valid before CLKO ↑ 0.25 TCY + 25 — — ns (Note 1) 16 TckH2ioI Port In Hold after CLKO ↑ 0 — — ns (Note 1) 17 TosH2ioV OSC1 ↑ (Q1 cycle) to Port Out Valid — 50 150 ns 18 TosH2ioI OSC1 ↑ (Q2 cycle) to Port Input Invalid (I/O in hold time) PIC18FXXXX 100 — — ns 18A PIC18LFXXXX 200 — — ns VDD = 2.0V 19 TioV2osH Port Input Valid to OSC1 ↑ (I/O in setup time) 0 — — ns 20 TioR Port Output Rise Time PIC18FXXXX — 10 25 ns 20A PIC18LFXXXX — — 60 ns VDD = 2.0V 21 TioF Port Output Fall Time PIC18FXXXX — 10 25 ns 21A PIC18LFXXXX — — 60 ns VDD = 2.0V 22† TINP INTx pin High or Low Time TCY — — ns 23† TRBP RB<7:4> Change INTx High or Low Time TCY — — ns † These parameters are asynchronous events not related to any internal clock edges. Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC. Note: Refer to Figure 26-5 for load conditions. OSC1 CLKO I/O pin (Input) I/O pin (Output) Q4 Q1 Q2 Q3 10 13 14 17 20, 21 19 18 15 11 12 16 Old Value New Value© 2008 Microchip Technology Inc. DS39631E-page 345 PIC18F2420/2520/4420/4520 FIGURE 26-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING FIGURE 26-9: BROWN-OUT RESET TIMING TABLE 26-10: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER AND BROWN-OUT RESET REQUIREMENTS Param. No. Symbol Characteristic Min Typ Max Units Conditions 30 TmcL MCLR Pulse Width (low) 2 — — μs 31 TWDT Watchdog Timer Time-out Period (no postscaler) 3.4 4.1 4.71 ms 32 TOST Oscillation Start-up Timer Period 1024 TOSC — 1024 TOSC — TOSC = OSC1 period 33 TPWRT Power-up Timer Period 55.6 65.5 75.4 ms 34 TIOZ I/O High-Impedance from MCLR Low or Watchdog Timer Reset —2— μs 35 TBOR Brown-out Reset Pulse Width 200 — — μs VDD ≤ BVDD (see D005) 36 TIRVST Time for Internal Reference Voltage to become Stable — 20 50 μs 37 TLVD High/Low-Voltage Detect Pulse Width 200 — — μs VDD ≤ VLVD 38 TCSD CPU Start-up Time — 10 — μs 39 TIOBST Time for INTOSC to Stabilize — 1 — μs VDD MCLR Internal POR PWRT Time-out OSC Time-out Internal Reset Watchdog Timer Reset 33 32 30 31 34 I/O pins 34 Note: Refer to Figure 26-5 for load conditions. VDD BVDD 35 VIRVST Enable Internal Internal Reference 36 Reference Voltage Voltage StablePIC18F2420/2520/4420/4520 DS39631E-page 346 © 2008 Microchip Technology Inc. FIGURE 26-10: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS TABLE 26-11: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS Param No. Symbol Characteristic Min Max Units Conditions 40 Tt0H T0CKI High Pulse Width No prescaler 0.5 TCY + 20 — ns With prescaler 10 — ns 41 Tt0L T0CKI Low Pulse Width No prescaler 0.5 TCY + 20 — ns With prescaler 10 — ns 42 Tt0P T0CKI Period No prescaler TCY + 10 — ns With prescaler Greater of: 20 ns or (TCY + 40)/N — ns N = prescale value (1, 2, 4,..., 256) 45 Tt1H T13CKI High Time Synchronous, no prescaler 0.5 TCY + 20 — ns Synchronous, with prescaler PIC18FXXXX 10 — ns PIC18LFXXXX 25 — ns VDD = 2.0V Asynchronous PIC18FXXXX 30 — ns PIC18LFXXXX 50 — ns VDD = 2.0V 46 Tt1L T13CKI Low Time Synchronous, no prescaler 0.5 TCY + 5 — ns Synchronous, with prescaler PIC18FXXXX 10 — ns PIC18LFXXXX 25 — ns VDD = 2.0V Asynchronous PIC18FXXXX 30 — ns PIC18LFXXXX 50 — ns VDD = 2.0V 47 Tt1P T13CKI Input Period Synchronous Greater of: 20 ns or (TCY + 40)/N — ns N = prescale value (1, 2, 4, 8) Asynchronous 60 — ns Ft1 T13CKI Oscillator Input Frequency Range DC 50 kHz 48 Tcke2tmrI Delay from External T13CKI Clock Edge to Timer Increment 2 TOSC 7 TOSC — Note: Refer to Figure 26-5 for load conditions. 46 47 45 48 41 42 40 T0CKI T1OSO/T13CKI TMR0 or TMR1© 2008 Microchip Technology Inc. DS39631E-page 347 PIC18F2420/2520/4420/4520 FIGURE 26-11: CAPTURE/COMPARE/PWM TIMINGS (ALL CCP MODULES) TABLE 26-12: CAPTURE/COMPARE/PWM REQUIREMENTS (ALL CCP MODULES) Param No. Symbol Characteristic Min Max Units Conditions 50 TccL CCPx Input Low Time No prescaler 0.5 TCY + 20 — ns With prescaler PIC18FXXXX 10 — ns PIC18LFXXXX 20 — ns VDD = 2.0V 51 TccH CCPx Input High Time No prescaler 0.5 TCY + 20 — ns With prescaler PIC18FXXXX 10 — ns PIC18LFXXXX 20 — ns VDD = 2.0V 52 TccP CCPx Input Period 3 TCY + 40 N — ns N = prescale value (1, 4 or 16) 53 TccR CCPx Output Fall Time PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 54 TccF CCPx Output Fall Time PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V Note: Refer to Figure 26-5 for load conditions. CCPx (Capture Mode) 50 51 52 CCPx 53 54 (Compare or PWM Mode)PIC18F2420/2520/4420/4520 DS39631E-page 348 © 2008 Microchip Technology Inc. FIGURE 26-12: PARALLEL SLAVE PORT TIMING (PIC18F4420/4520) TABLE 26-13: PARALLEL SLAVE PORT REQUIREMENTS (PIC18F4420, PIC18F4520) Param. No. Symbol Characteristic Min Max Units Conditions 62 TdtV2wrH Data In Valid before WR ↑ or CS ↑ (setup time) 20 — ns 63 TwrH2dtI WR ↑ or CS ↑ to Data–In Invalid (hold time) PIC18FXXXX 20 — ns PIC18LFXXXX 35 — ns VDD = 2.0V 64 TrdL2dtV RD ↓ and CS ↓ to Data–Out Valid — 80 ns 65 TrdH2dtI RD ↑ or CS ↓ to Data–Out Invalid 10 30 ns 66 TibfINH Inhibit of the IBF Flag bit being Cleared from WR ↑ or CS ↑ — 3 TCY Note: Refer to Figure 26-5 for load conditions. RE2/CS RE0/RD RE1/WR RD<7:0> 62 63 64 65© 2008 Microchip Technology Inc. DS39631E-page 349 PIC18F2420/2520/4420/4520 FIGURE 26-13: EXAMPLE SPI MASTER MODE TIMING (CKE = 0) TABLE 26-14: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0) Param No. Symbol Characteristic Min Max Units Conditions 70 TssL2scH, TssL2scL SS ↓ to SCK ↓ or SCK ↑ Input TCY — ns 73 TdiV2scH, TdiV2scL Setup Time of SDI Data Input to SCK Edge 20 — ns 73A Tb2b Last Clock Edge of Byte 1 to the 1st Clock Edge of Byte 2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold Time of SDI Data Input to SCK Edge 40 — ns 75 TdoR SDO Data Output Rise Time PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 76 TdoF SDO Data Output Fall Time — 25 ns 78 TscR SCK Output Rise Time (Master mode) PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 79 TscF SCK Output Fall Time (Master mode) — 25 ns 80 TscH2doV, TscL2doV SDO Data Output Valid after SCK Edge PIC18FXXXX — 50 ns PIC18LFXXXX — 100 ns VDD = 2.0V Note 1: Requires the use of Parameter #73A. 2: Only if Parameter #71A and #72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 70 71 72 73 74 75, 76 79 78 80 78 79 MSb LSb bit 6 - - - - - -1 MSb In bit 6 - - - -1 LSb In Note: Refer to Figure 26-5 for load conditions.PIC18F2420/2520/4420/4520 DS39631E-page 350 © 2008 Microchip Technology Inc. FIGURE 26-14: EXAMPLE SPI MASTER MODE TIMING (CKE = 1) TABLE 26-15: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1) Param. No. Symbol Characteristic Min Max Units Conditions 73 TdiV2scH, TdiV2scL Setup Time of SDI Data Input to SCK Edge 20 — ns 73A Tb2b Last Clock Edge of Byte 1 to the 1st Clock Edge of Byte 2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold Time of SDI Data Input to SCK Edge 40 — ns 75 TdoR SDO Data Output Rise Time PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 76 TdoF SDO Data Output Fall Time — 25 ns 78 TscR SCK Output Rise Time (Master mode) PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 79 TscF SCK Output Fall Time (Master mode) — 25 ns 80 TscH2doV, TscL2doV SDO Data Output Valid after SCK Edge PIC18FXXXX — 50 ns PIC18LFXXXX — 100 ns VDD = 2.0V 81 TdoV2scH, TdoV2scL SDO Data Output Setup to SCK Edge TCY — ns Note 1: Requires the use of Parameter #73A. 2: Only if Parameter #71A and #72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 81 71 72 74 75, 76 78 80 MSb 79 73 MSb In bit 6 - - - - - -1 bit 6 - - - -1 LSb In LSb Note: Refer to Figure 26-5 for load conditions.© 2008 Microchip Technology Inc. DS39631E-page 351 PIC18F2420/2520/4420/4520 FIGURE 26-15: EXAMPLE SPI SLAVE MODE TIMING (CKE = 0) TABLE 26-16: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0) Param No. Symbol Characteristic Min Max Units Conditions 70 TssL2scH, TssL2scL SS ↓ to SCK ↓ or SCK ↑ Input 3 TCY — ns 71 TscH SCK Input High Time (Slave mode) Continuous 1.25 TCY + 30 — ns 71A Single Byte 40 — ns (Note 1) 72 TscL SCK Input Low Time (Slave mode) Continuous 1.25 TCY + 30 — ns 72A Single Byte 40 — ns (Note 1) 73 TdiV2scH, TdiV2scL Setup Time of SDI Data Input to SCK Edge 20 — ns 73A Tb2b Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold Time of SDI Data Input to SCK Edge 40 — ns 75 TdoR SDO Data Output Rise Time PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 76 TdoF SDO Data Output Fall Time — 25 ns 77 TssH2doZ SS ↑ to SDO Output High-Impedance 10 50 ns 80 TscH2doV, TscL2doV SDO Data Output Valid after SCK Edge PIC18FXXXX — 50 ns PIC18LFXXXX — 100 ns VDD = 2.0V 83 TscH2ssH, TscL2ssH SS ↑ after SCK edge 1.5 TCY + 40 — ns Note 1: Requires the use of Parameter #73A. 2: Only if Parameter #71A and #72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 70 71 72 73 74 75, 76 77 79 78 80 78 79 SDI MSb LSb bit 6 - - - - - -1 bit 6 - - - -1 LSb In 83 Note: Refer to Figure 26-5 for load conditions. MSb InPIC18F2420/2520/4420/4520 DS39631E-page 352 © 2008 Microchip Technology Inc. FIGURE 26-16: EXAMPLE SPI SLAVE MODE TIMING (CKE = 1) TABLE 26-17: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1) Param No. Symbol Characteristic Min Max Units Conditions 70 TssL2scH, TssL2scL SS ↓ to SCK ↓ or SCK ↑ Input 3 TCY — ns 71 TscH SCK Input High Time (Slave mode) Continuous 1.25 TCY + 30 — ns 71A Single Byte 40 — ns (Note 1) 72 TscL SCK Input Low Time (Slave mode) Continuous 1.25 TCY + 30 — ns 72A Single Byte 40 — ns (Note 1) 73A Tb2b Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold Time of SDI Data Input to SCK Edge 40 — ns 75 TdoR SDO Data Output Rise Time PIC18FXXXX — 25 ns PIC18LFXXXX — 45 ns VDD = 2.0V 76 TdoF SDO Data Output Fall Time — 25 ns 77 TssH2doZ SS ↑ to SDO Output High-Impedance 10 50 ns 80 TscH2doV, TscL2doV SDO Data Output Valid after SCK Edge PIC18FXXXX — 50 ns PIC18LFXXXX — 100 ns VDD = 2.0V 82 TssL2doV SDO Data Output Valid after SS ↓ Edge PIC18FXXXX — 50 ns PIC18LFXXXX — 100 ns VDD = 2.0V 83 TscH2ssH, TscL2ssH SS ↑ after SCK Edge 1.5 TCY + 40 — ns Note 1: Requires the use of Parameter #73A. 2: Only if Parameter #71A and #72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 70 71 72 82 74 75, 76 MSb bit 6 - - - - - -1 LSb 77 MSb In bit 6 - - - -1 LSb In 80 83 Note: Refer to Figure 26-5 for load conditions.© 2008 Microchip Technology Inc. DS39631E-page 353 PIC18F2420/2520/4420/4520 FIGURE 26-17: I2C™ BUS START/STOP BITS TIMING TABLE 26-18: I2C™ BUS START/STOP BITS REQUIREMENTS (SLAVE MODE) FIGURE 26-18: I2C™ BUS DATA TIMING Param. No. Symbol Characteristic Min Max Units Conditions 90 TSU:STA Start Condition 100 kHz mode 4700 — ns Only relevant for Repeated Setup Time 400 kHz mode 600 — Start condition 91 THD:STA Start Condition 100 kHz mode 4000 — ns After this period, the first Hold Time 400 kHz mode 600 — clock pulse is generated 92 TSU:STO Stop Condition 100 kHz mode 4700 — ns Setup Time 400 kHz mode 600 — 93 THD:STO Stop Condition 100 kHz mode 4000 — ns Hold Time 400 kHz mode 600 — Note: Refer to Figure 26-5 for load conditions. 91 92 93 SCL SDA Start Condition Stop Condition 90 Note: Refer to Figure 26-5 for load conditions. 90 91 92 100 101 103 106 107 109 109 110 102 SCL SDA In SDA OutPIC18F2420/2520/4420/4520 DS39631E-page 354 © 2008 Microchip Technology Inc. TABLE 26-19: I2C™ BUS DATA REQUIREMENTS (SLAVE MODE) Param. No. Symbol Characteristic Min Max Units Conditions 100 THIGH Clock High Time 100 kHz mode 4.0 — μs 400 kHz mode 0.6 — μs MSSP module 1.5 TCY — 101 TLOW Clock Low Time 100 kHz mode 4.7 — μs 400 kHz mode 1.3 — μs MSSP module 1.5 TCY — 102 TR SDA and SCL Rise Time 100 kHz mode — 1000 ns 400 kHz mode 20 + 0.1 CB 300 ns CB is specified to be from 10 to 400 pF 103 TF SDA and SCL Fall Time 100 kHz mode — 300 ns 400 kHz mode 20 + 0.1 CB 300 ns CB is specified to be from 10 to 400 pF 90 TSU:STA Start Condition Setup Time 100 kHz mode 4.7 — μs Only relevant for Repeated Start condition 400 kHz mode 0.6 — μs 91 THD:STA Start Condition Hold Time 100 kHz mode 4.0 — μs After this period, the first clock pulse is generated 400 kHz mode 0.6 — μs 106 THD:DAT Data Input Hold Time 100 kHz mode 0 — ns 400 kHz mode 0 0.9 μs 107 TSU:DAT Data Input Setup Time 100 kHz mode 250 — ns (Note 2) 400 kHz mode 100 — ns 92 TSU:STO Stop Condition Setup Time 100 kHz mode 4.7 — μs 400 kHz mode 0.6 — μs 109 TAA Output Valid from Clock 100 kHz mode — 3500 ns (Note 1) 400 kHz mode — — ns 110 TBUF Bus Free Time 100 kHz mode 4.7 — μs Time the bus must be free before a new transmission can start 400 kHz mode 1.3 — μs D102 CB Bus Capacitive Loading — 400 pF Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions. 2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but the requirement TSU:DAT ≥ 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification), before the SCL line is released. © 2008 Microchip Technology Inc. DS39631E-page 355 PIC18F2420/2520/4420/4520 FIGURE 26-19: MASTER SSP I2C™ BUS START/STOP BITS TIMING WAVEFORMS TABLE 26-20: MASTER SSP I2C™ BUS START/STOP BITS REQUIREMENTS FIGURE 26-20: MASTER SSP I2C™ BUS DATA TIMING Param. No. Symbol Characteristic Min Max Units Conditions 90 TSU:STA Start Condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Only relevant for Repeated Start condition Setup Time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — 91 THD:STA Start Condition 100 kHz mode 2(TOSC)(BRG + 1) — ns After this period, the first clock pulse is generated Hold Time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — 92 TSU:STO Stop Condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Setup Time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — 93 THD:STO Stop Condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Hold Time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — Note 1: Maximum pin capacitance = 10 pF for all I2C pins. Note: Refer to Figure 26-5 for load conditions. 91 93 SCL SDA Start Condition Stop Condition 90 92 Note: Refer to Figure 26-5 for load conditions. 90 91 92 100 101 103 106 107 109 109 110 102 SCL SDA In SDA OutPIC18F2420/2520/4420/4520 DS39631E-page 356 © 2008 Microchip Technology Inc. TABLE 26-21: MASTER SSP I2C™ BUS DATA REQUIREMENTS Param. No. Symbol Characteristic Min Max Units Conditions 100 THIGH Clock High Time 100 kHz mode 2(TOSC)(BRG + 1) — ms 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 101 TLOW Clock Low Time 100 kHz mode 2(TOSC)(BRG + 1) — ms 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 102 TR SDA and SCL Rise Time 100 kHz mode — 1000 ns CB is specified to be from 10 to 400 pF 400 kHz mode 20 + 0.1 CB 300 ns 1 MHz mode(1) — 300 ns 103 TF SDA and SCL Fall Time 100 kHz mode — 300 ns CB is specified to be from 10 to 400 pF 400 kHz mode 20 + 0.1 CB 300 ns 1 MHz mode(1) — 100 ns 90 TSU:STA Start Condition Setup Time 100 kHz mode 2(TOSC)(BRG + 1) — ms Only relevant for Repeated Start condition 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 91 THD:STA Start Condition Hold Time 100 kHz mode 2(TOSC)(BRG + 1) — ms After this period, the first clock pulse is generated 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 106 THD:DAT Data Input Hold Time 100 kHz mode 0 — ns 400 kHz mode 0 0.9 ms 107 TSU:DAT Data Input Setup Time 100 kHz mode 250 — ns (Note 2) 400 kHz mode 100 — ns 92 TSU:STO Stop Condition Setup Time 100 kHz mode 2(TOSC)(BRG + 1) — ms 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 109 TAA Output Valid from Clock 100 kHz mode — 3500 ns 400 kHz mode — 1000 ns 1 MHz mode(1) — — ns 110 TBUF Bus Free Time 100 kHz mode 4.7 — ms Time the bus must be free before a new transmission can start 400 kHz mode 1.3 — ms D102 CB Bus Capacitive Loading — 400 pF Note 1: Maximum pin capacitance = 10 pF for all I2C pins. 2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter 107 ≥ 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, parameter 102 + parameter 107 = 1000 + 250 = 1250 ns (for 100 kHz mode), before the SCL line is released.© 2008 Microchip Technology Inc. DS39631E-page 357 PIC18F2420/2520/4420/4520 FIGURE 26-21: EUSART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING TABLE 26-22: EUSART SYNCHRONOUS TRANSMISSION REQUIREMENTS Param No. Symbol Characteristic Min Max Units Conditions 120 TckH2dtV SYNC XMIT (MASTER & SLAVE) Clock High to Data Out Valid PIC18FXXXX — 40 ns PIC18LFXXXX — 100 ns VDD = 2.0V 121 Tckrf Clock Out Rise Time and Fall Time (Master mode) PIC18FXXXX — 20 ns PIC18LFXXXX — 50 ns VDD = 2.0V 122 Tdtrf Data Out Rise Time and Fall Time PIC18FXXXX — 20 ns PIC18LFXXXX — 50 ns VDD = 2.0V 121 121 120 122 RC6/TX/CK RC7/RX/DT pin pin Note: Refer to Figure 26-5 for load conditions.PIC18F2420/2520/4420/4520 DS39631E-page 358 © 2008 Microchip Technology Inc. FIGURE 26-22: EUSART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING TABLE 26-23: EUSART SYNCHRONOUS RECEIVE REQUIREMENTS TABLE 26-24: A/D CONVERTER CHARACTERISTICS: PIC18F2420/2520/4420/4520 (INDUSTRIAL) PIC18LF2420/2520/4420/4520 (INDUSTRIAL) Param. No. Symbol Characteristic Min Max Units Conditions 125 TdtV2ckl SYNC RCV (MASTER & SLAVE) Data Hold before CK ↓ (DT hold time) 10 — ns 126 TckL2dtl Data Hold after CK ↓ (DT hold time) 15 — ns Param No. Symbol Characteristic Min Typ Max Units Conditions A01 NR Resolution — — 10 bit ΔVREF ≥ 3.0V A03 EIL Integral Linearity Error — — <±1 LSb ΔVREF ≥ 3.0V A04 EDL Differential Linearity Error — — <±1 LSb ΔVREF ≥ 3.0V A06 EOFF Offset Error — — <±2.0 LSb ΔVREF ≥ 3.0V A07 EGN Gain Error — — <±1 LSb ΔVREF ≥ 3.0V A10 — Monotonicity Guaranteed(1) — VSS ≤ VAIN ≤ VREF A20 ΔVREF Reference Voltage Range (VREFH – VREFL) 1.8 3 — — — — V V VDD < 3.0V VDD ≥ 3.0V A21 VREFH Reference Voltage High VSS — VREFH V A22 VREFL Reference Voltage Low VSS – 0.3V — VDD – 3.0V V A25 VAIN Analog Input Voltage VREFL — VREFH V A30 ZAIN Recommended Impedance of Analog Voltage Source — — 2.5 kΩ A40 IAD A/D Current from VDD PIC18FXXXX — 180 — μA Average current during PIC18 conversion LFXX20 — 90 — μA A50 IREF VREF Input Current(2) — — — — 5 150 μA μA During VAIN acquisition. During A/D conversion cycle. Note 1: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes. 2: VREFH current is from RA3/AN3/VREF+ pin or VDD, whichever is selected as the VREFH source. VREFL current is from RA2/AN2/VREF-/CVREF pin or VSS, whichever is selected as the VREFL source. 125 126 RC6/TX/CK RC7/RX/DT pin pin Note: Refer to Figure 26-5 for load conditions.© 2008 Microchip Technology Inc. DS39631E-page 359 PIC18F2420/2520/4420/4520 FIGURE 26-23: A/D CONVERSION TIMING TABLE 26-25: A/D CONVERSION REQUIREMENTS Param No. Symbol Characteristic Min Max Units Conditions 130 TAD A/D Clock Period PIC18FXXXX 0.7 25.0(1) μs TOSC based, VREF ≥ 3.0V PIC18LFXXXX 1.4 25.0(1) μs VDD = 2.0V; TOSC based, VREF full range PIC18FXXXX — 1 μs A/D RC mode PIC18LFXXXX — 3 μs VDD = 2.0V; A/D RC mode 131 TCNV Conversion Time (not including acquisition time) (Note 2) 11 12 TAD 132 TACQ Acquisition Time (Note 3) 1.4 — μs -40°C to +85°C 135 TSWC Switching Time from Convert → Sample — (Note 4) TBD TDIS Discharge Time 0.2 — μs Note 1: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider. 2: ADRES register may be read on the following TCY cycle. 3: The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50Ω. 4: On the following cycle of the device clock. 131 130 132 BSF ADCON0, GO Q4 A/D CLK(1) A/D DATA ADRES ADIF GO SAMPLE OLD_DATA SAMPLING STOPPED DONE NEW_DATA (Note 2) 9 87 2 1 0 Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. 2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input. . . . . . . TCYPIC18F2420/2520/4420/4520 DS39631E-page 360 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 361 PIC18F2420/2520/4420/4520 27.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES “Typical” represents the mean of the distribution at 25°C. “Maximum” or “minimum” represents (mean + 3σ) or (mean – 3σ) respectively, where σ is a standard deviation, over the whole temperature range. FIGURE 27-1: SLEEP MODE Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore, outside the warranted range. 0.01 0.1 1 10 100 -50 -25 0 25 50 75 100 125 Temp (C) Ipd (uA) 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 Test instrument results are compressed to about 0.05 μA for actual values below 0.05 mA. Measurements below 0.01 mA are suspect and considered unmeasurable. This is supported by the instrument specifications.PIC18F2420/2520/4420/4520 DS39631E-page 362 © 2008 Microchip Technology Inc. FIGURE 27-2: TYPICAL IPD vs. VDD ACROSS TEMPERATURE (SLEEP MODE) FIGURE 27-3: MAXIMUM IPD vs. VDD ACROSS TEMPERATURE (SLEEP MODE) 0.01 0.1 1 10 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) 125°C 85°C 25°C -40°C 0.01 0.1 1 10 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) 125°C 85°C 25°C -40°C© 2008 Microchip Technology Inc. DS39631E-page 363 PIC18F2420/2520/4420/4520 FIGURE 27-4: TYPICAL T1OSC DELTA CURRENT vs. VDD ACROSS TEMP. (DEVICE IN SLEEP, T1OSC IN LOW-POWER MODE) FIGURE 27-5: MAXIMUM T1OSC DELTA CURRENT vs. VDD ACROSS TEMP. (DEVICE IN SLEEP, TIOSC IN LOW-POWER MODE) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) 85°C 25°C -10°C 0 1 2 3 4 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) 85°C 25°C -10°CPIC18F2420/2520/4420/4520 DS39631E-page 364 © 2008 Microchip Technology Inc. FIGURE 27-6: TYPICAL T1OSC DELTA CURRENT vs. VDD ACROSS TEMP. (DEVICE IN SLEEP, T1OSC IN HIGH-POWER MODE) FIGURE 27-7: MAXIMUM T1OSC DELTA CURRENT vs. VDD ACROSS TEMP. (DEVICE IN SLEEP, T1OSC IN HIGH-POWER MODE) 0 2 4 6 8 10 12 14 16 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 DD IPD (uA) 85°C 25°C -40°C 0 5 10 15 20 25 30 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) IPD (uA) 85°C 25°C -40°C© 2008 Microchip Technology Inc. DS39631E-page 365 PIC18F2420/2520/4420/4520 FIGURE 27-8: TYPICAL BOR DELTA CURRENT vs. VDD ACROSS TEMP. (BORV = 2.7V, SLEEP MODE) 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 2 2.5 3 3.5 4 4.5 5 5.5 VDD (V) IPD (uA) MAX (85°C) MAX TYP (25°C) MIN (-40°C) Device in SLEEP Device Held in RESETPIC18F2420/2520/4420/4520 DS39631E-page 366 © 2008 Microchip Technology Inc. FIGURE 27-9: TYPICAL WDT CURRENT vs. VDD ACROSS TEMPERATURE (WDT DELTA CURRENT IN SLEEP MODE) FIGURE 27-10: MAXIMUM WDT CURRENT vs. VDD ACROSS TEMPERATURE (WDT DELTA CURRENT IN SLEEP MODE) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) 125°C 85°C 25°C -40°C 0.0 2.0 4.0 6.0 8.0 10.0 12.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) 125°C 85°C 25°C -40°C© 2008 Microchip Technology Inc. DS39631E-page 367 PIC18F2420/2520/4420/4520 FIGURE 27-11: TYPICAL IDD ACROSS VDD (RC_RUN MODE, +25°C) FIGURE 27-12: MAXIMUM IDD ACROSS VDD (RC_RUN MODE, +85°C) 0.1 1 10 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (mA) 8 MHz 4 MHz 2 MHz 1 MHz 250 kHz 500 kHz 125 kHz 4.2V 0.1 1 10 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (mA) 8 MHz 4.2V 4 MHz 2 MHz 1 MHz 250 kHz 500 kHz 125 kHzPIC18F2420/2520/4420/4520 DS39631E-page 368 © 2008 Microchip Technology Inc. FIGURE 27-13: TYPICAL AND MAXIMUM IDD ACROSS VDD (RC_RUN MODE, 31 kHz) FIGURE 27-14: TYPICAL IDD ACROSS VDD (RC_IDLE MODE, +25°C) 10 100 1000 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (uA) Maximum (-40°C) Typical (25°C) 0.01 0.1 1 10 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (mA) 8 MHz 4.2V 4 MHz 2 MHz 1 MHz 250 kHz 500 kHz 125 kHz© 2008 Microchip Technology Inc. DS39631E-page 369 PIC18F2420/2520/4420/4520 FIGURE 27-15: MAXIMUM IDD ACROSS VDD (RC_IDLE MODE, -40°C TO +85°C) FIGURE 27-16: TYPICAL AND MAXIMUM IDD ACROSS VDD (RC_IDLE MODE, 31 kHz) 0.1 1 10 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (mA) 8 MHz 4.2V 4 MHz 2 MHz 1 MHz 250 kHz 500 kHz 125 kHz 0 5 10 15 20 25 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (uA) Maximum (85°C) Typical (25°C)PIC18F2420/2520/4420/4520 DS39631E-page 370 © 2008 Microchip Technology Inc. FIGURE 27-17: TYPICAL AND MAXIMUM SEC_RUN CURRENT vs. VDD ACROSS TEMPERATURE (T1OSC IN LOW-POWER MODE) FIGURE 27-18: TYPICAL AND MAXIMUM SEC_IDLE CURRENT vs. VDD ACROSS TEMPERATURE (T1OSC IN LOW-POWER MODE) 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (uA) Max (-10°C) Typ (25°C) Typ (85°C) Typ (-10°C) 0.0 2.0 4.0 6.0 8.0 10.0 12.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (uA) Max (85°C) 14.0 Typ (85°C) Typ (-10°C) Typ (25°C)© 2008 Microchip Technology Inc. DS39631E-page 371 PIC18F2420/2520/4420/4520 FIGURE 27-19: TYPICAL IDD vs. FOSC, 500 kHz TO 4 MHz (PRI_RUN MODE (EC CLOCK), +25°C) FIGURE 27-20: MAXIMUM IDD vs. FOSC, 500 kHz TO 4 MHz (PRI_RUN MODE (EC CLOCK), -40°C TO +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0VPIC18F2420/2520/4420/4520 DS39631E-page 372 © 2008 Microchip Technology Inc. FIGURE 27-21: TYPICAL IDD vs. FOSC, 4 MHz TO 40 MHz (PRI_RUN MODE (EC CLOCK), +25°C) FIGURE 27-22: MAXIMUM IDD vs. FOSC, 4 MHz TO 40 MHz (PRI_RUN MODE (EC CLOCK), -40°C TO +125°C) 0 2 4 6 8 10 12 14 16 18 20 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 0 2 4 6 8 10 12 14 16 18 20 22 24 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V© 2008 Microchip Technology Inc. DS39631E-page 373 PIC18F2420/2520/4420/4520 FIGURE 27-23: TYPICAL IDD vs. FOSC, HS/PLL (PRI_RUN MODE, +25°C) FIGURE 27-24: MAXIMUM IDD vs. FOSC, HS/PLL (PRI_RUN MODE, -40°C) 4 6 8 10 12 14 16 18 20 22 24 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.2V 4 6 8 10 12 14 16 18 20 22 24 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.2VPIC18F2420/2520/4420/4520 DS39631E-page 374 © 2008 Microchip Technology Inc. FIGURE 27-25: TYPICAL IDD vs. FOSC, 500 kHz TO 4 MHz (PRI_IDLE MODE, +25°C) FIGURE 27-26: MAXIMUM IDD vs. FOSC, 500 kHz TO 4 MHz (PRI_IDLE MODE, -40°C TO +125°C) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Fosc (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Fosc (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V© 2008 Microchip Technology Inc. DS39631E-page 375 PIC18F2420/2520/4420/4520 FIGURE 27-27: TYPICAL IDD vs. FOSC, 4 MHz TO 40 MHz (PRI_IDLE MODE, +25°C) FIGURE 27-28: MAXIMUM IDD vs. FOSC, 4 MHz TO 40 MHz (PRI_IDLE MODE, -40°C TO +125°C) 0 1 2 3 4 5 6 7 8 9 10 11 12 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5V 0 1 2 3 4 5 6 7 8 9 10 11 12 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.0V 5.5V 4.0V 4.5V 3.0V 3.5V 2.0V 2.5VPIC18F2420/2520/4420/4520 DS39631E-page 376 © 2008 Microchip Technology Inc. FIGURE 27-29: TYPICAL IDD vs. FOSC, HS/PLL (PRI_IDLE MODE, +25°C) FIGURE 27-30: MAXIMUM IDD vs. FOSC, HS/PLL (PRI_IDLE MODE, -40°C) 0 1 2 3 4 5 6 7 8 9 10 11 12 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.2V 0 1 2 3 4 5 6 7 8 9 10 11 12 16 18 20 22 24 26 28 30 32 34 36 38 40 Fosc (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.2V© 2008 Microchip Technology Inc. DS39631E-page 377 PIC18F2420/2520/4420/4520 FIGURE 27-31: VIN (ST) vs. VDD, +25°C (-40°C TO +125°C) FIGURE 27-32: VIN (TTL) vs. VDD, +25°C (-40°C TO +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) VIN (V) VIH Max (125°C) VIH Typ (25°C) VIH Min (-40°C) VIL Min (125°C) VIL Typ (25°C) VIL Max (-40°C) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) VIN (V) VIH Min (125°C) VIH Typ (25°C) VIH Max (-40°C)PIC18F2420/2520/4420/4520 DS39631E-page 378 © 2008 Microchip Technology Inc. FIGURE 27-33: VOL vs. IOL (VDD = 3.0V, -40°C TO +85°C) FIGURE 27-34: VOL vs. IOL (VDD = 5.0V, -40°C TO +125°C) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 5 10 15 20 25 IOL (-ma) VOL (V) Typ (25°C) Min (-40°C) Max (85°C) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 5 10 15 20 25 IOL (-ma) VOL (V) Min (-40°C) Max (85°C) Typ (25°C)© 2008 Microchip Technology Inc. DS39631E-page 379 PIC18F2420/2520/4420/4520 FIGURE 27-35: VOH vs. IOH (VDD = 3.0V, -40°C TO +85°C) FIGURE 27-36: VOH vs. IOH (VDD = 5.0V, -40°C TO +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 5 10 15 20 25 IOH (-ma) VOH (V) Max (-40°C) Typ (25°C) Min (85°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 5 10 15 20 25 IOH (-ma) VOH (V) Max (-40°C) Typ (25°C) Min (125°C)PIC18F2420/2520/4420/4520 DS39631E-page 380 © 2008 Microchip Technology Inc. FIGURE 27-37: INTOSC FREQUENCY vs. VDD, TEMPERATURE (-40°C, +25°C, +85°C, +125°C) FIGURE 27-38: INTRC vs. VDD ACROSS TEMPERATURE (-40°C TO +125°C) 7.6 7.7 7.8 7.9 8.0 8.1 8.2 8.3 8.4 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (MHz) Max Freq 125°C Typ 85°C Typ 25°C Typ -40°C Typ Min Freq 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (kHz) Max (125°C) Max (-40°C) Typ (25°C) Min (85°C) Min (125°C)© 2008 Microchip Technology Inc. DS39631E-page 381 PIC18F2420/2520/4420/4520 FIGURE 27-39: WDT PERIOD vs. VDD ACROSS TEMPERATURE (1:1 POSTSCALER, -40°C TO +125°C) 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Period (ms) Longest Typical (25°C) Shortest (85°C) Shortest (125°C)PIC18F2420/2520/4420/4520 DS39631E-page 382 © 2008 Microchip Technology Inc. NOTES:© 2008 Microchip Technology Inc. DS39631E-page 383 PIC18F2420/2520/4420/4520 28.0 PACKAGING INFORMATION 28.1 Package Marking Information 28-Lead SPDIP XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F2520-I/SP 0810017 28-Lead SOIC XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F2520-E/SO 0810017 Legend: XX...X Customer-specific information Y Year code (last digit of calendar year) YY Year code (last 2 digits of calendar year) WW Week code (week of January 1 is week ‘01’) NNN Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) * This package is Pb-free. The Pb-free JEDEC designator ( ) can be found on the outer packaging for this package. Note: In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. e3 e3 e3 e3 28-Lead QFN XXXXXXXX XXXXXXXX YYWWNNN Example 18F2420 -I/ML 0810017 e3PIC18F2420/2520/4420/4520 DS39631E-page 384 © 2008 Microchip Technology Inc. Package Marking Information (Continued) 44-Lead TQFP XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN Example PIC18F4420 -I/PT 0810017 XXXXXXXXXX 44-Lead QFN XXXXXXXXXX XXXXXXXXXX YYWWNNN PIC18F4520 Example -I/ML 0810017 e3 e3 40-Lead PDIP XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F4420-I/P 0810017 © 2006 Microchip Technology Inc. DS39564C PIC18FXX2 Data Sheet High-Performance, Enhanced Flash Microcontrollers with 10-Bit A/DDS39564C-page ii © 2006 Microchip Technology Inc. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Linear Active Thermistor, Mindi, MiWi, MPASM, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, rfPICDEM, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2006, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. • Microchip is willing to work with the customer who is concerned about the integrity of their code. • Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.” Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona, Gresham, Oregon and Mountain View, California. The Company’s quality system processes and procedures are for its PICmicro® 8-bit MCUs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.© 2006 Microchip Technology Inc. DS39564C-page 1 PIC18FXX2 High Performance RISC CPU: • C compiler optimized architecture/instruction set - Source code compatible with the PIC16 and PIC17 instruction sets • Linear program memory addressing to 32 Kbytes • Linear data memory addressing to 1.5 Kbytes • Up to 10 MIPs operation: - DC - 40 MHz osc./clock input - 4 MHz - 10 MHz osc./clock input with PLL active • 16-bit wide instructions, 8-bit wide data path • Priority levels for interrupts • 8 x 8 Single Cycle Hardware Multiplier Peripheral Features: • High current sink/source 25 mA/25 mA • Three external interrupt pins • Timer0 module: 8-bit/16-bit timer/counter with 8-bit programmable prescaler • Timer1 module: 16-bit timer/counter • Timer2 module: 8-bit timer/counter with 8-bit period register (time-base for PWM) • Timer3 module: 16-bit timer/counter • Secondary oscillator clock option - Timer1/Timer3 • Two Capture/Compare/PWM (CCP) modules. CCP pins that can be configured as: - Capture input: capture is 16-bit, max. resolution 6.25 ns (TCY/16) - Compare is 16-bit, max. resolution 100 ns (TCY) - PWM output: PWM resolution is 1- to 10-bit, max. PWM freq. @: 8-bit resolution = 156 kHz 10-bit resolution = 39 kHz • Master Synchronous Serial Port (MSSP) module, Two modes of operation: - 3-wire SPI™ (supports all 4 SPI modes) - I2C™ Master and Slave mode Peripheral Features (Continued): • Addressable USART module: - Supports RS-485 and RS-232 • Parallel Slave Port (PSP) module Analog Features: • Compatible 10-bit Analog-to-Digital Converter module (A/D) with: - Fast sampling rate - Conversion available during SLEEP - Linearity ≤ 1 LSb • Programmable Low Voltage Detection (PLVD) - Supports interrupt on-Low Voltage Detection • Programmable Brown-out Reset (BOR) Special Microcontroller Features: • 100,000 erase/write cycle Enhanced FLASH program memory typical • 1,000,000 erase/write cycle Data EEPROM memory • FLASH/Data EEPROM Retention: > 40 years • Self-reprogrammable under software control • Power-on Reset (POR), Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) • Watchdog Timer (WDT) with its own On-Chip RC Oscillator for reliable operation • Programmable code protection • Power saving SLEEP mode • Selectable oscillator options including: - 4X Phase Lock Loop (of primary oscillator) - Secondary Oscillator (32 kHz) clock input • Single supply 5V In-Circuit Serial Programming™ (ICSP™) via two pins • In-Circuit Debug (ICD) via two pins CMOS Technology: • Low power, high speed FLASH/EEPROM technology • Fully static design • Wide operating voltage range (2.0V to 5.5V) • Industrial and Extended temperature ranges • Low power consumption: - < 1.6 mA typical @ 5V, 4 MHz - 25 μA typical @ 3V, 32 kHz - < 0.2 μA typical standby current Device On-Chip Program Memory On-Chip RAM (bytes) Data EEPROM FLASH (bytes) (bytes) # Single Word Instructions PIC18F242 16K 8192 768 256 PIC18F252 32K 16384 1536 256 PIC18F442 16K 8192 768 256 PIC18F452 32K 16384 1536 256 28/40-pin High Performance, Enhanced FLASH Microcontrollers with 10-Bit A/DPIC18FXX2 DS39564C-page 2 © 2006 Microchip Technology Inc. Pin Diagrams 10 11 12 13 14 15 16 1718 19 20 21 22 23 24 25 26 44 8 7 6 5 4 3 2 1 27 28 29 30 31 32 33 34 35 36 37 38 39 43 42 41 40 9 PIC18F442 RA4/T0CKI RA5/AN4/SS/LVDIN RE0/RD/AN5 OSC2/CLKO/RA6 NC RE1/WR/AN6 RE2/CS/AN7 VDD OSC1/CLKI RB3/CCP2* RB2/INT2 RB1/INT1 RB0/INT0 VDD VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1 RA0/AN0 MCLR/VPP NC RB7/PGD RB6/PGC RB5/PGM RB4 NC RC1/T1OSI/CCP2 RC2/CCP1 RC3/SCK/SCL RD0/PSP0 RD1/PSP1 RD2/PSP2 RD3/PSP3 RC4/SDI/SDA RC5/SDO RC6/TX/CK NC * 10 11 2 3 4 5 6 1 12 13 14 15 18 19 20 21 22 38 8 7 44 43 42 41 40 39 16 17 29 30 31 32 33 23 24 25 26 27 28 36 35 34 9 PIC18F44237 RA3/AN3/VREF+ RA2/AN2/VREFMCLR RA0/AN0 RA1/AN1 /VPP NC NC RB4 RB5/PGM RB6/PGC RB7/PGD RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 RD1/PSP1 RD0/PSP0 RC3/SCK/SCL RC2/CCP1 RC1/T1OSI/CCP2* NC NC RC0/T1OSO/T1CKI OSC2/CLKO/RA6 OSC1/CLKI VSS VDD RE2/AN7/CS RE1/AN6/WR RE0/AN5/RD RA5/AN4/SS/LVDIN RA4/T0CKI RC7/RX/DT RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7 VSS VDD RB0/INT0 RB1/INT1 RB2/INT2 RB3/CCP2* PLCC TQFP * RB3 is the alternate pin for the CCP2 pin multiplexing. VSS RC0/T1OSO/T1CKI PIC18F452 PIC18F452© 2006 Microchip Technology Inc. DS39564C-page 3 PIC18FXX2 Pin Diagrams (Cont.’d) RB7/PGD RB6/PGC RB5/PGM RB4 RB3/CCP2* RB2/INT2 RB1/INT1 RB0/INT0 VDD VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 MCLR/VPP RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4/SS/LVDIN RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VDD VSS OSC1/CLKI OSC2/CLKO/RA6 RC0/T1OSO/T1CKI RC1/T1OSI/CCP2* RC2/CCP1 RC3/SCK/SCL RD0/PSP0 RD1/PSP1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 PIC18F442 10 PIC18F242 11 2 3 4 5 6 1 8 7 9 12 13 14 15 16 17 18 19 20 23 24 25 26 27 28 22 21 MCLR/VPP RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4/SS/LVDIN VSS OSC1/CLKI OSC2/CLKO/RA6 RC0/T1OSO/T1CKI RC1/T1OSI/CCP2* RC2/CCP1 RC3/SCK/SCL RB7/PGD RB6/PGC RB5/PGM RB4 RB3/CCP2* RB2/INT2 RB1/INT1 RB0/INT0 VDD VSS RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA * RB3 is the alternate pin for the CCP2 pin multiplexing. DIP DIP, SOIC Note: Pin compatible with 40-pin PIC16C7X devices. PIC18F452 PIC18F252PIC18FXX2 DS39564C-page 4 © 2006 Microchip Technology Inc. Table of Contents 1.0 Device Overview .......................................................................................................................................................................... 7 2.0 Oscillator Configurations ............................................................................................................................................................ 17 3.0 Reset .......................................................................................................................................................................................... 25 4.0 Memory Organization ................................................................................................................................................................. 35 5.0 FLASH Program Memory ........................................................................................................................................................... 55 6.0 Data EEPROM Memory ............................................................................................................................................................. 65 7.0 8 X 8 Hardware Multiplier ........................................................................................................................................................... 71 8.0 Interrupts .................................................................................................................................................................................... 73 9.0 I/O Ports ..................................................................................................................................................................................... 87 10.0 Timer0 Module ......................................................................................................................................................................... 103 11.0 Timer1 Module ......................................................................................................................................................................... 107 12.0 Timer2 Module ......................................................................................................................................................................... 111 13.0 Timer3 Module ......................................................................................................................................................................... 113 14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 117 15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 125 16.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART).............................................................. 165 17.0 Compatible 10-bit Analog-to-Digital Converter (A/D) Module................................................................................................... 181 18.0 Low Voltage Detect .................................................................................................................................................................. 189 19.0 Special Features of the CPU.................................................................................................................................................... 195 20.0 Instruction Set Summary .......................................................................................................................................................... 211 21.0 Development Support............................................................................................................................................................... 253 22.0 Electrical Characteristics .......................................................................................................................................................... 259 23.0 DC and AC Characteristics Graphs and Tables....................................................................................................................... 289 24.0 Packaging Information.............................................................................................................................................................. 305 Appendix A: Revision History............................................................................................................................................................ 313 Appendix B: Device Differences........................................................................................................................................................ 313 Appendix C: Conversion Considerations........................................................................................................................................... 314 Appendix D: Migration from Baseline to Enhanced Devices ............................................................................................................. 314 Appendix E: Migration from Mid-range to Enhanced Devices........................................................................................................... 315 Appendix F: Migration from High-end to Enhanced Devices ............................................................................................................ 315 Index .................................................................................................................................................................................................. 317 On-Line Support................................................................................................................................................................................. 327 Reader Response .............................................................................................................................................................................. 328 PIC18FXX2 Product Identification System......................................................................................................................................... 329© 2006 Microchip Technology Inc. DS39564C-page 5 PIC18FXX2 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000). Errata An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: • Microchip’s Worldwide Web site; http://www.microchip.com • Your local Microchip sales office (see last page) When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are using. Customer Notification System Register on our web site at www.microchip.com to receive the most current information on all of our products.PIC18FXX2 DS39564C-page 6 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 7 PIC18FXX2 1.0 DEVICE OVERVIEW This document contains device specific information for the following devices: These devices come in 28-pin and 40/44-pin packages. The 28-pin devices do not have a Parallel Slave Port (PSP) implemented and the number of Analog-toDigital (A/D) converter input channels is reduced to 5. An overview of features is shown in Table 1-1. The following two figures are device block diagrams sorted by pin count: 28-pin for Figure 1-1 and 40/44-pin for Figure 1-2. The 28-pin and 40/44-pin pinouts are listed in Table 1-2 and Table 1-3, respectively. TABLE 1-1: DEVICE FEATURES • PIC18F242 • PIC18F442 • PIC18F252 • PIC18F452 Features PIC18F242 PIC18F252 PIC18F442 PIC18F452 Operating Frequency DC - 40 MHz DC - 40 MHz DC - 40 MHz DC - 40 MHz Program Memory (Bytes) 16K 32K 16K 32K Program Memory (Instructions) 8192 16384 8192 16384 Data Memory (Bytes) 768 1536 768 1536 Data EEPROM Memory (Bytes) 256 256 256 256 Interrupt Sources 17 17 18 18 I/O Ports Ports A, B, C Ports A, B, C Ports A, B, C, D, E Ports A, B, C, D, E Timers 4 4 4 4 Capture/Compare/PWM Modules 2 2 2 2 Serial Communications MSSP, Addressable USART MSSP, Addressable USART MSSP, Addressable USART MSSP, Addressable USART Parallel Communications — — PSP PSP 10-bit Analog-to-Digital Module 5 input channels 5 input channels 8 input channels 8 input channels RESETS (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST) POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST) POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST) POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST) Programmable Low Voltage Detect Yes Yes Yes Yes Programmable Brown-out Reset Yes Yes Yes Yes Instruction Set 75 Instructions 75 Instructions 75 Instructions 75 Instructions Packages 28-pin DIP 28-pin SOIC 28-pin DIP 28-pin SOIC 40-pin DIP 44-pin PLCC 44-pin TQFP 40-pin DIP 44-pin PLCC 44-pin TQFPPIC18FXX2 DS39564C-page 8 © 2006 Microchip Technology Inc. FIGURE 1-1: PIC18F2X2 BLOCK DIAGRAM Instruction Decode & Control PORTA PORTB PORTC RA4/T0CKI RA5/AN4/SS/LVDIN RC0/T1OSO/T1CKI RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT Note 1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit. 2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction). 3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations are device dependent. Addressable CCP1 Synchronous Timer0 Timer1 Timer2 Serial Port RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1 RA0/AN0 A/D Converter Data Latch Data RAM Address Latch Address<12> 12(2) BSR FSR0 FSR1 FSR2 4 12 4 PCH PCL PCLATH 8 31 Level Stack Program Counter PRODH PRODL 8 x 8 Multiply WREG 8 BIT OP 8 8 ALU<8> 8 Address Latch Program Memory (up to 2 Mbytes) Data Latch 21 21 16 8 8 8 inc/dec logic 21 8 Data Bus<8> 8 Instruction 12 3 ROM Latch Timer3 CCP2 Bank0, F PCLATU PCU RA6 USART Master 8 Register Table Latch Table Pointer inc/dec Decode logic RB0/INT0 RB4 RB1/INT1 RB2/INT2 RB3/CCP2(1) RB5/PGM RB6/PCG RB7/PGD Data EEPROM Power-up Timer Oscillator Start-up Timer Power-on Reset Watchdog Timer OSC1/CLKI OSC2/CLKO MCLR VDD, VSS Brown-out Reset Timing Generation 4X PLL T1OSCI T1OSCO Precision Reference Voltage Low Voltage Programming In-Circuit Debugger© 2006 Microchip Technology Inc. DS39564C-page 9 PIC18FXX2 FIGURE 1-2: PIC18F4X2 BLOCK DIAGRAM Power-up Timer Oscillator Start-up Timer Power-on Reset Watchdog Timer Instruction Decode & Control OSC1/CLKI OSC2/CLKO MCLR VDD, VSS PORTA PORTB PORTC RA4/T0CKI RA5/AN4/SS/LVDIN RB0/INT0 RB4 RC0/T1OSO/T1CKI RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT Brown-out Reset Note 1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit. 2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction). 3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations are device dependent. Addressable CCP1 Master Timer0 Timer1 Timer2 Serial Port RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1 RA0/AN0 Parallel Slave Port Timing Generation 4X PLL A/D Converter RB1/INT1 Data Latch Data RAM (up to 4K address reach) Address Latch Address<12> 12(2) BSR FSR0 Bank0, F FSR1 FSR2 4 12 4 PCH PCL PCLATH 8 31 Level Stack Program Counter PRODH PRODL 8 x 8 Multiply WREG 8 BIT OP 8 8 ALU<8> 8 Address Latch Program Memory (up to 2 Mbytes) Data Latch 21 21 16 8 8 8 inc/dec logic 21 8 Data Bus<8> Table Latch 8 Instruction 12 3 ROM Latch Timer3 PORTD PORTE RE0/AN5/RD RE1/AN6/WR RE2/AN7/CS CCP2 RB2/INT2 RB3/CCP2(1) T1OSCI T1OSCO PCLATU PCU RA6 Precision Reference Voltage Synchronous USART Register 8 Table Pointer inc/dec logic Decode RD0/PSP0 RD1/PSP1 RD2/PSP2 RD3/PSP3 RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7 Low Voltage Programming In-Circuit Debugger Data EEPROM RB5/PGM RB6/PCG RB7/PGDPIC18FXX2 DS39564C-page 10 © 2006 Microchip Technology Inc. TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS Pin Name Pin Number Pin Type Buffer Type Description DIP SOIC MCLR/VPP MCLR VPP 1 1 I I ST ST Master Clear (input) or high voltage ICSP programming enable pin. Master Clear (Reset) input. This pin is an active low RESET to the device. High voltage ICSP programming enable pin. NC — — — — These pins should be left unconnected. OSC1/CLKI OSC1 CLKI 9 9 I I ST CMOS Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) OSC2/CLKO/RA6 OSC2 CLKO RA6 10 10 O O I/O — — TTL Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate. General Purpose I/O pin. PORTA is a bi-directional I/O port. RA0/AN0 RA0 AN0 2 2 I/O I TTL Analog Digital I/O. Analog input 0. RA1/AN1 RA1 AN1 3 3 I/O I TTL Analog Digital I/O. Analog input 1. RA2/AN2/VREFRA2 AN2 VREF- 4 4 I/O I I TTL Analog Analog Digital I/O. Analog input 2. A/D Reference Voltage (Low) input. RA3/AN3/VREF+ RA3 AN3 VREF+ 5 5 I/O I I TTL Analog Analog Digital I/O. Analog input 3. A/D Reference Voltage (High) input. RA4/T0CKI RA4 T0CKI 6 6 I/O I ST/OD ST Digital I/O. Open drain when configured as output. Timer0 external clock input. RA5/AN4/SS/LVDIN RA5 AN4 SS LVDIN 7 7 I/O I I I TTL Analog ST Analog Digital I/O. Analog input 4. SPI Slave Select input. Low Voltage Detect Input. RA6 See the OSC2/CLKO/RA6 pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) © 2006 Microchip Technology Inc. DS39564C-page 11 PIC18FXX2 PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0 RB0 INT0 21 21 I/O I TTL ST Digital I/O. External Interrupt 0. RB1/INT1 RB1 INT1 22 22 I/O I TTL ST External Interrupt 1. RB2/INT2 RB2 INT2 23 23 I/O I TTL ST Digital I/O. External Interrupt 2. RB3/CCP2 RB3 CCP2 24 24 I/O I/O TTL ST Digital I/O. Capture2 input, Compare2 output, PWM2 output. RB4 25 25 I/O TTL Digital I/O. Interrupt-on-change pin. RB5/PGM RB5 PGM 26 26 I/O I/O TTL ST Digital I/O. Interrupt-on-change pin. Low Voltage ICSP programming enable pin. RB6/PGC RB6 PGC 27 27 I/O I/O TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming clock pin. RB7/PGD RB7 PGD 28 28 I/O I/O TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description DIP SOIC Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) PIC18FXX2 DS39564C-page 12 © 2006 Microchip Technology Inc. PORTC is a bi-directional I/O port. RC0/T1OSO/T1CKI RC0 T1OSO T1CKI 11 11 I/O O I ST — ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. RC1/T1OSI/CCP2 RC1 T1OSI CCP2 12 12 I/O I I/O ST CMOS ST Digital I/O. Timer1 oscillator input. Capture2 input, Compare2 output, PWM2 output. RC2/CCP1 RC2 CCP1 13 13 I/O I/O ST ST Digital I/O. Capture1 input/Compare1 output/PWM1 output. RC3/SCK/SCL RC3 SCK SCL 14 14 I/O I/O I/O ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2C mode RC4/SDI/SDA RC4 SDI SDA 15 15 I/O I I/O ST ST ST Digital I/O. SPI Data In. I 2C Data I/O. RC5/SDO RC5 SDO 16 16 I/O O ST — Digital I/O. SPI Data Out. RC6/TX/CK RC6 TX CK 17 17 I/O O I/O ST — ST Digital I/O. USART Asynchronous Transmit. USART Synchronous Clock (see related RX/DT). RC7/RX/DT RC7 RX DT 18 18 I/O I I/O ST ST ST Digital I/O. USART Asynchronous Receive. USART Synchronous Data (see related TX/CK). VSS 8, 19 8, 19 P — Ground reference for logic and I/O pins. VDD 20 20 P — Positive supply for logic and I/O pins. TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description DIP SOIC Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) © 2006 Microchip Technology Inc. DS39564C-page 13 PIC18FXX2 TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS Pin Name Pin Number Pin Type Buffer Type Description DIP PLCC TQFP MCLR/VPP MCLR VPP 1 2 18 I I ST ST Master Clear (input) or high voltage ICSP programming enable pin. Master Clear (Reset) input. This pin is an active low RESET to the device. High voltage ICSP programming enable pin. NC — — — These pins should be left unconnected. OSC1/CLKI OSC1 CLKI 13 14 30 I I ST CMOS Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) OSC2/CLKO/RA6 OSC2 CLKO RA6 14 15 31 O O I/O — — TTL Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General Purpose I/O pin. PORTA is a bi-directional I/O port. RA0/AN0 RA0 AN0 2 3 19 I/O I TTL Analog Digital I/O. Analog input 0. RA1/AN1 RA1 AN1 3 4 20 I/O I TTL Analog Digital I/O. Analog input 1. RA2/AN2/VREFRA2 AN2 VREF- 4 5 21 I/O I I TTL Analog Analog Digital I/O. Analog input 2. A/D Reference Voltage (Low) input. RA3/AN3/VREF+ RA3 AN3 VREF+ 5 6 22 I/O I I TTL Analog Analog Digital I/O. Analog input 3. A/D Reference Voltage (High) input. RA4/T0CKI RA4 T0CKI 6 7 23 I/O I ST/OD ST Digital I/O. Open drain when configured as output. Timer0 external clock input. RA5/AN4/SS/LVDIN RA5 AN4 SS LVDIN 7 8 24 I/O I I I TTL Analog ST Analog Digital I/O. Analog input 4. SPI Slave Select input. Low Voltage Detect Input. RA6 (See the OSC2/CLKO/RA6 pin.) Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) PIC18FXX2 DS39564C-page 14 © 2006 Microchip Technology Inc. PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0 RB0 INT0 33 36 8 I/O I TTL ST Digital I/O. External Interrupt 0. RB1/INT1 RB1 INT1 34 37 9 I/O I TTL ST External Interrupt 1. RB2/INT2 RB2 INT2 35 38 10 I/O I TTL ST Digital I/O. External Interrupt 2. RB3/CCP2 RB3 CCP2 36 39 11 I/O I/O TTL ST Digital I/O. Capture2 input, Compare2 output, PWM2 output. RB4 37 41 14 I/O TTL Digital I/O. Interrupt-on-change pin. RB5/PGM RB5 PGM 38 42 15 I/O I/O TTL ST Digital I/O. Interrupt-on-change pin. Low Voltage ICSP programming enable pin. RB6/PGC RB6 PGC 39 43 16 I/O I/O TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming clock pin. RB7/PGD RB7 PGD 40 44 17 I/O I/O TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description DIP PLCC TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) © 2006 Microchip Technology Inc. DS39564C-page 15 PIC18FXX2 PORTC is a bi-directional I/O port. RC0/T1OSO/T1CKI RC0 T1OSO T1CKI 15 16 32 I/O O I ST — ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. RC1/T1OSI/CCP2 RC1 T1OSI CCP2 16 18 35 I/O I I/O ST CMOS ST Digital I/O. Timer1 oscillator input. Capture2 input, Compare2 output, PWM2 output. RC2/CCP1 RC2 CCP1 17 19 36 I/O I/O ST ST Digital I/O. Capture1 input/Compare1 output/PWM1 output. RC3/SCK/SCL RC3 SCK SCL 18 20 37 I/O I/O I/O ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I 2C mode. RC4/SDI/SDA RC4 SDI SDA 23 25 42 I/O I I/O ST ST ST Digital I/O. SPI Data In. I 2C Data I/O. RC5/SDO RC5 SDO 24 26 43 I/O O ST — Digital I/O. SPI Data Out. RC6/TX/CK RC6 TX CK 25 27 44 I/O O I/O ST — ST Digital I/O. USART Asynchronous Transmit. USART Synchronous Clock (see related RX/DT). RC7/RX/DT RC7 RX DT 26 29 1 I/O I I/O ST ST ST Digital I/O. USART Asynchronous Receive. USART Synchronous Data (see related TX/CK). TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description DIP PLCC TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) PIC18FXX2 DS39564C-page 16 © 2006 Microchip Technology Inc. PORTD is a bi-directional I/O port, or a Parallel Slave Port (PSP) for interfacing to a microprocessor port. These pins have TTL input buffers when PSP module is enabled. RD0/PSP0 19 21 38 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD1/PSP1 20 22 39 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD2/PSP2 21 23 40 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD3/PSP3 22 24 41 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD4/PSP4 27 30 2 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD5/PSP5 28 31 3 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD6/PSP6 29 32 4 I/O ST TTL Digital I/O. Parallel Slave Port Data. RD7/PSP7 30 33 5 I/O ST TTL Digital I/O. Parallel Slave Port Data. PORTE is a bi-directional I/O port. RE0/RD/AN5 RE0 RD AN5 8 9 25 I/O ST TTL Analog Digital I/O. Read control for parallel slave port (see also WR and CS pins). Analog input 5. RE1/WR/AN6 RE1 WR AN6 9 10 26 I/O ST TTL Analog Digital I/O. Write control for parallel slave port (see CS and RD pins). Analog input 6. RE2/CS/AN7 RE2 CS AN7 10 11 27 I/O ST TTL Analog Digital I/O. Chip Select control for parallel slave port (see related RD and WR). Analog input 7. VSS 12, 31 13, 34 6, 29 P — Ground reference for logic and I/O pins. VDD 11, 32 12, 35 7, 28 P — Positive supply for logic and I/O pins. TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number Pin Type Buffer Type Description DIP PLCC TQFP Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels I = Input O = Output P = Power OD = Open Drain (no P diode to VDD) © 2006 Microchip Technology Inc. DS39564C-page 17 PIC18FXX2 2.0 OSCILLATOR CONFIGURATIONS 2.1 Oscillator Types The PIC18FXX2 can be operated in eight different Oscillator modes. The user can program three configuration bits (FOSC2, FOSC1, and FOSC0) to select one of these eight modes: 1. LP Low Power Crystal 2. XT Crystal/Resonator 3. HS High Speed Crystal/Resonator 4. HS + PLL High Speed Crystal/Resonator with PLL enabled 5. RC External Resistor/Capacitor 6. RCIO External Resistor/Capacitor with I/O pin enabled 7. EC External Clock 8. ECIO External Clock with I/O pin enabled 2.2 Crystal Oscillator/Ceramic Resonators In XT, LP, HS or HS+PLL Oscillator modes, a crystal or ceramic resonator is connected to the OSC1 and OSC2 pins to establish oscillation. Figure 2-1 shows the pin connections. The PIC18FXX2 oscillator design requires the use of a parallel cut crystal. FIGURE 2-1: CRYSTAL/CERAMIC RESONATOR OPERATION (HS, XT OR LP CONFIGURATION) TABLE 2-1: CAPACITOR SELECTION FOR CERAMIC RESONATORS Note: Use of a series cut crystal may give a frequency out of the crystal manufacturers specifications. Note 1: See Table 2-1 and Table 2-2 for recommended values of C1 and C2. 2: A series resistor (RS) may be required for AT strip cut crystals. 3: RF varies with the Oscillator mode chosen. C1(1) C2(1) XTAL OSC2 OSC1 RF(3) SLEEP To Logic PIC18FXXX RS(2) Internal Ranges Tested: Mode Freq C1 C2 XT 455 kHz 2.0 MHz 4.0 MHz 68 - 100 pF 15 - 68 pF 15 - 68 pF 68 - 100 pF 15 - 68 pF 15 - 68 pF HS 8.0 MHz 16.0 MHz 10 - 68 pF 10 - 22 pF 10 - 68 pF 10 - 22 pF These values are for design guidance only. See notes following this table. Resonators Used: 455 kHz Panasonic EFO-A455K04B ± 0.3% 2.0 MHz Murata Erie CSA2.00MG ± 0.5% 4.0 MHz Murata Erie CSA4.00MG ± 0.5% 8.0 MHz Murata Erie CSA8.00MT ± 0.5% 16.0 MHz Murata Erie CSA16.00MX ± 0.5% All resonators used did not have built-in capacitors. Note 1: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 2: When operating below 3V VDD, or when using certain ceramic resonators at any voltage, it may be necessary to use high-gain HS mode, try a lower frequency resonator, or switch to a crystal oscillator. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components, or verify oscillator performance. PIC18FXX2 DS39564C-page 18 © 2006 Microchip Technology Inc. TABLE 2-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR An external clock source may also be connected to the OSC1 pin in the HS, XT and LP modes, as shown in Figure 2-2. FIGURE 2-2: EXTERNAL CLOCK INPUT OPERATION (HS, XT OR LP OSC CONFIGURATION) 2.3 RC Oscillator For timing-insensitive applications, the “RC” and “RCIO” device options offer additional cost savings. The RC oscillator frequency is a function of the supply voltage, the resistor (REXT) and capacitor (CEXT) values and the operating temperature. In addition to this, the oscillator frequency will vary from unit to unit due to normal process parameter variation. Furthermore, the difference in lead frame capacitance between package types will also affect the oscillation frequency, especially for low CEXT values. The user also needs to take into account variation due to tolerance of external R and C components used. Figure 2-3 shows how the R/C combination is connected. In the RC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. FIGURE 2-3: RC OSCILLATOR MODE The RCIO Oscillator mode functions like the RC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). Ranges Tested: Mode Freq C1 C2 LP 32.0 kHz 33 pF 33 pF 200 kHz 15 pF 15 pF XT 200 kHz 22-68 pF 22-68 pF 1.0 MHz 15 pF 15 pF 4.0 MHz 15 pF 15 pF HS 4.0 MHz 15 pF 15 pF 8.0 MHz 15-33 pF 15-33 pF 20.0 MHz 15-33 pF 15-33 pF 25.0 MHz 15-33 pF 15-33 pF These values are for design guidance only. See notes following this table. Crystals Used 32.0 kHz Epson C-001R32.768K-A ± 20 PPM 200 kHz STD XTL 200.000KHz ± 20 PPM 1.0 MHz ECS ECS-10-13-1 ± 50 PPM 4.0 MHz ECS ECS-40-20-1 ± 50 PPM 8.0 MHz Epson CA-301 8.000M-C ± 30 PPM 20.0 MHz Epson CA-301 20.000M-C ± 30 PPM Note 1: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 2: Rs may be required in HS mode, as well as XT mode, to avoid overdriving crystals with low drive level specification. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components., or verify oscillator performance. OSC1 Open OSC2 Clock from Ext. System PIC18FXXX Note: If the oscillator frequency divided by 4 signal is not required in the application, it is recommended to use RCIO mode to save current. OSC2/CLKO CEXT REXT PIC18FXXX OSC1 FOSC/4 Internal Clock VDD VSS Recommended values:3 kΩ ≤ REXT ≤ 100 kΩ CEXT > 20pF© 2006 Microchip Technology Inc. DS39564C-page 19 PIC18FXX2 2.4 External Clock Input The EC and ECIO Oscillator modes require an external clock source to be connected to the OSC1 pin. The feedback device between OSC1 and OSC2 is turned off in these modes to save current. There is no oscillator start-up time required after a Power-on Reset or after a recovery from SLEEP mode. In the EC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 2-4 shows the pin connections for the EC Oscillator mode. FIGURE 2-4: EXTERNAL CLOCK INPUT OPERATION (EC CONFIGURATION) The ECIO Oscillator mode functions like the EC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). Figure 2-5 shows the pin connections for the ECIO Oscillator mode. FIGURE 2-5: EXTERNAL CLOCK INPUT OPERATION (ECIO CONFIGURATION) 2.5 HS/PLL A Phase Locked Loop circuit is provided as a programmable option for users that want to multiply the frequency of the incoming crystal oscillator signal by 4. For an input clock frequency of 10 MHz, the internal clock frequency will be multiplied to 40 MHz. This is useful for customers who are concerned with EMI due to high frequency crystals. The PLL can only be enabled when the oscillator configuration bits are programmed for HS mode. If they are programmed for any other mode, the PLL is not enabled and the system clock will come directly from OSC1. The PLL is one of the modes of the FOSC<2:0> configuration bits. The Oscillator mode is specified during device programming. A PLL lock timer is used to ensure that the PLL has locked before device execution starts. The PLL lock timer has a time-out that is called TPLL. FIGURE 2-6: PLL BLOCK DIAGRAM OSC1 FOSC/4 OSC2 Clock from Ext. System PIC18FXXX OSC1 RA6 I/O (OSC2) Clock from Ext. System PIC18FXXX MUX VCO Loop Filter Divide by 4 Crystal Osc OSC2 OSC1 PLL Enable FIN FOUT SYSCLK Phase Comparator (from Configuration HS Osc bit Register)PIC18FXX2 DS39564C-page 20 © 2006 Microchip Technology Inc. 2.6 Oscillator Switching Feature The PIC18FXX2 devices include a feature that allows the system clock source to be switched from the main oscillator to an alternate low frequency clock source. For the PIC18FXX2 devices, this alternate clock source is the Timer1 oscillator. If a low frequency crystal (32 kHz, for example) has been attached to the Timer1 oscillator pins and the Timer1 oscillator has been enabled, the device can switch to a Low Power Execution mode. Figure 2-7 shows a block diagram of the system clock sources. The clock switching feature is enabled by programming the Oscillator Switching Enable (OSCSEN) bit in Configuration Register1H to a ’0’. Clock switching is disabled in an erased device. See Section 11.0 for further details of the Timer1 oscillator. See Section 19.0 for Configuration Register details. FIGURE 2-7: DEVICE CLOCK SOURCES PIC18FXXX TOSC 4 x PLL TT1P TSCLK Clock Source MUX TOSC/4 Timer1 Oscillator T1OSCEN Enable Oscillator T1OSO T1OSI Clock Source option for other modules OSC1 OSC2 SLEEP Main Oscillator© 2006 Microchip Technology Inc. DS39564C-page 21 PIC18FXX2 2.6.1 SYSTEM CLOCK SWITCH BIT The system clock source switching is performed under software control. The system clock switch bit, SCS (OSCCON<0>) controls the clock switching. When the SCS bit is ’0’, the system clock source comes from the main oscillator that is selected by the FOSC configuration bits in Configuration Register1H. When the SCS bit is set, the system clock source will come from the Timer1 oscillator. The SCS bit is cleared on all forms of RESET. REGISTER 2-1: OSCCON REGISTER Note: The Timer1 oscillator must be enabled and operating to switch the system clock source. The Timer1 oscillator is enabled by setting the T1OSCEN bit in the Timer1 control register (T1CON). If the Timer1 oscillator is not enabled, then any write to the SCS bit will be ignored (SCS bit forced cleared) and the main oscillator will continue to be the system clock source. U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-1 — — — — — — — SCS bit 7 bit 0 bit 7-1 Unimplemented: Read as '0' bit 0 SCS: System Clock Switch bit When OSCSEN configuration bit = ’0’ and T1OSCEN bit is set: 1 = Switch to Timer1 oscillator/clock pin 0 = Use primary oscillator/clock input pin When OSCSEN and T1OSCEN are in other states: bit is forced clear Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 22 © 2006 Microchip Technology Inc. 2.6.2 OSCILLATOR TRANSITIONS The PIC18FXX2 devices contain circuitry to prevent “glitches” when switching between oscillator sources. Essentially, the circuitry waits for eight rising edges of the clock source that the processor is switching to. This ensures that the new clock source is stable and that its pulse width will not be less than the shortest pulse width of the two clock sources. A timing diagram indicating the transition from the main oscillator to the Timer1 oscillator is shown in Figure 2-8. The Timer1 oscillator is assumed to be running all the time. After the SCS bit is set, the processor is frozen at the next occurring Q1 cycle. After eight synchronization cycles are counted from the Timer1 oscillator, operation resumes. No additional delays are required after the synchronization cycles. FIGURE 2-8: TIMING DIAGRAM FOR TRANSITION FROM OSC1 TO TIMER1 OSCILLATOR The sequence of events that takes place when switching from the Timer1 oscillator to the main oscillator will depend on the mode of the main oscillator. In addition to eight clock cycles of the main oscillator, additional delays may take place. If the main oscillator is configured for an external crystal (HS, XT, LP), then the transition will take place after an oscillator start-up time (TOST) has occurred. A timing diagram, indicating the transition from the Timer1 oscillator to the main oscillator for HS, XT and LP modes, is shown in Figure 2-9. FIGURE 2-9: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS, XT, LP) Q2 Q3 Q4 Q1 Q2 Q3 OSC1 Internal SCS (OSCCON<0>) Program PC PC + 2 Note 1: Delay on internal system clock is eight oscillator cycles for synchronization. Q1 T1OSI Q4 Q1 PC + 4 Q1 Tscs Clock Counter System Q2 Q3 Q4 Q1 TDLY TT1P TOSC 1 34 5678 2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 OSC1 Internal System SCS (OSCCON<0>) Program Counter PC PC + 2 Note 1: TOST = 1024 TOSC (drawing not to scale). T1OSI Clock OSC2 TOST Q1 PC + 6 TT1P TOSC TSCS 1 2 34 567 8© 2006 Microchip Technology Inc. DS39564C-page 23 PIC18FXX2 If the main oscillator is configured for HS-PLL mode, an oscillator start-up time (TOST) plus an additional PLL time-out (TPLL) will occur. The PLL time-out is typically 2 ms and allows the PLL to lock to the main oscillator frequency. A timing diagram indicating the transition from the Timer1 oscillator to the main oscillator for HS-PLL mode is shown in Figure 2-10. FIGURE 2-10: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS WITH PLL) If the main oscillator is configured in the RC, RCIO, EC or ECIO modes, there is no oscillator start-up time-out. Operation will resume after eight cycles of the main oscillator have been counted. A timing diagram, indicating the transition from the Timer1 oscillator to the main oscillator for RC, RCIO, EC and ECIO modes, is shown in Figure 2-11. FIGURE 2-11: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (RC, EC) Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 OSC1 Internal System SCS (OSCCON<0>) Program Counter PC PC + 2 Note 1: TOST = 1024 TOSC (drawing not to scale). T1OSI Clock TOST Q3 PC + 4 TPLL TOSC TT1P TSCS Q4 OSC2 PLL Clock Input 1 234 5678 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 OSC1 Internal System SCS (OSCCON<0>) Program Counter PC PC + 2 Note 1: RC Oscillator mode assumed. PC + 4 T1OSI Clock OSC2 Q4 TT1P TOSC TSCS 1 2 3 4 5 6 7 8PIC18FXX2 DS39564C-page 24 © 2006 Microchip Technology Inc. 2.7 Effects of SLEEP Mode on the On-Chip Oscillator When the device executes a SLEEP instruction, the on-chip clocks and oscillator are turned off and the device is held at the beginning of an instruction cycle (Q1 state). With the oscillator off, the OSC1 and OSC2 signals will stop oscillating. Since all the transistor switching currents have been removed, SLEEP mode achieves the lowest current consumption of the device (only leakage currents). Enabling any on-chip feature that will operate during SLEEP will increase the current consumed during SLEEP. The user can wake from SLEEP through external RESET, Watchdog Timer Reset, or through an interrupt. TABLE 2-3: OSC1 AND OSC2 PIN STATES IN SLEEP MODE 2.8 Power-up Delays Power up delays are controlled by two timers, so that no external RESET circuitry is required for most applications. The delays ensure that the device is kept in RESET, until the device power supply and clock are stable. For additional information on RESET operation, see Section 3.0. The first timer is the Power-up Timer (PWRT), which optionally provides a fixed delay of 72 ms (nominal) on power-up only (POR and BOR). The second timer is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable. With the PLL enabled (HS/PLL Oscillator mode), the time-out sequence following a Power-on Reset is different from other Oscillator modes. The time-out sequence is as follows: First, the PWRT time-out is invoked after a POR time delay has expired. Then, the Oscillator Start-up Timer (OST) is invoked. However, this is still not a sufficient amount of time to allow the PLL to lock at high frequencies. The PWRT timer is used to provide an additional fixed 2 ms (nominal) time-out to allow the PLL ample time to lock to the incoming clock frequency. OSC Mode OSC1 Pin OSC2 Pin RC Floating, external resistor should pull high At logic low RCIO Floating, external resistor should pull high Configured as PORTA, bit 6 ECIO Floating Configured as PORTA, bit 6 EC Floating At logic low LP, XT, and HS Feedback inverter disabled, at quiescent voltage level Feedback inverter disabled, at quiescent voltage level Note: See Table 3-1, in the “Reset” section, for time-outs due to SLEEP and MCLR Reset.© 2006 Microchip Technology Inc. DS39564C-page 25 PIC18FXX2 3.0 RESET The PIC18FXXX differentiates between various kinds of RESET: a) Power-on Reset (POR) b) MCLR Reset during normal operation c) MCLR Reset during SLEEP d) Watchdog Timer (WDT) Reset (during normal operation) e) Programmable Brown-out Reset (BOR) f) RESET Instruction g) Stack Full Reset h) Stack Underflow Reset Most registers are unaffected by a RESET. Their status is unknown on POR and unchanged by all other RESETS. The other registers are forced to a “RESET state” on Power-on Reset, MCLR, WDT Reset, Brownout Reset, MCLR Reset during SLEEP and by the RESET instruction. Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. Status bits from the RCON register, RI, TO, PD, POR and BOR, are set or cleared differently in different RESET situations, as indicated in Table 3-2. These bits are used in software to determine the nature of the RESET. See Table 3-3 for a full description of the RESET states of all registers. A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 3-1. The Enhanced MCU devices have a MCLR noise filter in the MCLR Reset path. The filter will detect and ignore small pulses. The MCLR pin is not driven low by any internal RESETS, including the WDT. FIGURE 3-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT S R Q External Reset MCLR VDD OSC1 WDT Module VDD Rise Detect OST/PWRT On-chip RC OSC(1) WDT Time-out Power-on Reset OST 10-bit Ripple Counter PWRT Chip_Reset 10-bit Ripple Counter Reset Enable OST(2) Enable PWRT SLEEP Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin. 2: See Table 3-1 for time-out situations. Brown-out Reset BOREN RESET Instruction Stack Pointer Stack Full/Underflow ResetPIC18FXX2 DS39564C-page 26 © 2006 Microchip Technology Inc. 3.1 Power-On Reset (POR) A Power-on Reset pulse is generated on-chip when VDD rise is detected. To take advantage of the POR circuitry, just tie the MCLR pin directly (or through a resistor) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. A minimum rise rate for VDD is specified (parameter D004). For a slow rise time, see Figure 3-2. When the device starts normal operation (i.e., exits the RESET condition), device operating parameters (voltage, frequency, temperature, etc.) must be met to ensure operation. If these conditions are not met, the device must be held in RESET until the operating conditions are met. FIGURE 3-2: EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) 3.2 Power-up Timer (PWRT) The Power-up Timer provides a fixed nominal time-out (parameter 33) only on power-up from the POR. The Power-up Timer operates on an internal RC oscillator. The chip is kept in RESET as long as the PWRT is active. The PWRT’s time delay allows VDD to rise to an acceptable level. A configuration bit is provided to enable/disable the PWRT. The power-up time delay will vary from chip-to-chip due to VDD, temperature and process variation. See DC parameter D033 for details. 3.3 Oscillator Start-up Timer (OST) The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over (parameter 32). This ensures that the crystal oscillator or resonator has started and stabilized. The OST time-out is invoked only for XT, LP and HS modes and only on Power-on Reset or wake-up from SLEEP. 3.4 PLL Lock Time-out With the PLL enabled, the time-out sequence following a Power-on Reset is different from other Oscillator modes. A portion of the Power-up Timer is used to provide a fixed time-out that is sufficient for the PLL to lock to the main oscillator frequency. This PLL lock time-out (TPLL) is typically 2 ms and follows the oscillator start-up time-out (OST). 3.5 Brown-out Reset (BOR) A configuration bit, BOREN, can disable (if clear/ programmed), or enable (if set) the Brown-out Reset circuitry. If VDD falls below parameter D005 for greater than parameter 35, the brown-out situation will reset the chip. A RESET may not occur if VDD falls below parameter D005 for less than parameter 35. The chip will remain in Brown-out Reset until VDD rises above BVDD. If the Power-up Timer is enabled, it will be invoked after VDD rises above BVDD; it then will keep the chip in RESET for an additional time delay (parameter 33). If VDD drops below BVDD while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above BVDD, the Power-up Timer will execute the additional time delay. 3.6 Time-out Sequence On power-up, the time-out sequence is as follows: First, PWRT time-out is invoked after the POR time delay has expired. Then, OST is activated. The total time-out will vary based on oscillator configuration and the status of the PWRT. For example, in RC mode with the PWRT disabled, there will be no time-out at all. Figure 3-3, Figure 3-4, Figure 3-5, Figure 3-6 and Figure 3-7 depict time-out sequences on power-up. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, the time-outs will expire. Bringing MCLR high will begin execution immediately (Figure 3-5). This is useful for testing purposes or to synchronize more than one PIC18FXXX device operating in parallel. Table 3-2 shows the RESET conditions for some Special Function Registers, while Table 3-3 shows the RESET conditions for all the registers. Note 1: External Power-on Reset circuit is required only if the VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 kΩ is recommended to make sure that the voltage drop across R does not violate the device’s electrical specification. 3: R1 = 100Ω to 1 kΩ will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). C R1 D R VDD MCLR PIC18FXXX© 2006 Microchip Technology Inc. DS39564C-page 27 PIC18FXX2 TABLE 3-1: TIME-OUT IN VARIOUS SITUATIONS REGISTER 3-1: RCON REGISTER BITS AND POSITIONS TABLE 3-2: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER Oscillator Configuration Power-up(2) Brown-out Wake-up from SLEEP or PWRTE = 0 PWRTE = 1 Oscillator Switch HS with PLL enabled(1) 72 ms + 1024 TOSC + 2ms 1024 TOSC + 2 ms 72 ms(2) + 1024 TOSC + 2 ms 1024 TOSC + 2 ms HS, XT, LP 72 ms + 1024 TOSC 1024 TOSC 72 ms(2) + 1024 TOSC 1024 TOSC EC 72 ms — 72 ms(2) — External RC 72 ms — 72 ms(2) — Note 1: 2 ms is the nominal time required for the 4x PLL to lock. 2: 72 ms is the nominal power-up timer delay, if implemented. R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN — — RI TO PD POR BOR bit 7 bit 0 Note 1: Refer to Section 4.14 (page 53) for bit definitions. Condition Program Counter RCON Register RI TO PD POR BOR STKFUL STKUNF Power-on Reset 0000h 0--1 1100 1 1 1 0 0 u u MCLR Reset during normal operation 0000h 0--u uuuu u u u u u u u Software Reset during normal operation 0000h 0--0 uuuu 0 u u u u u u Stack Full Reset during normal operation 0000h 0--u uu11 u u u u u u 1 Stack Underflow Reset during normal operation 0000h 0--u uu11 u u u u u 1 u MCLR Reset during SLEEP 0000h 0--u 10uu u 1 0 u u u u WDT Reset 0000h 0--u 01uu 1 0 1 u u u u WDT Wake-up PC + 2 u--u 00uu u 0 0 u u u u Brown-out Reset 0000h 0--1 11u0 1 1 1 1 0 u u Interrupt wake-up from SLEEP PC + 2(1) u--u 00uu u 1 0 u u u u Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0' Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the interrupt vector (0x000008h or 0x000018h).PIC18FXX2 DS39564C-page 28 © 2006 Microchip Technology Inc. TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt TOSU 242 442 252 452 ---0 0000 ---0 0000 ---0 uuuu(3) TOSH 242 442 252 452 0000 0000 0000 0000 uuuu uuuu(3) TOSL 242 442 252 452 0000 0000 0000 0000 uuuu uuuu(3) STKPTR 242 442 252 452 00-0 0000 uu-0 0000 uu-u uuuu(3) PCLATU 242 442 252 452 ---0 0000 ---0 0000 ---u uuuu PCLATH 242 442 252 452 0000 0000 0000 0000 uuuu uuuu PCL 242 442 252 452 0000 0000 0000 0000 PC + 2(2) TBLPTRU 242 442 252 452 --00 0000 --00 0000 --uu uuuu TBLPTRH 242 442 252 452 0000 0000 0000 0000 uuuu uuuu TBLPTRL 242 442 252 452 0000 0000 0000 0000 uuuu uuuu TABLAT 242 442 252 452 0000 0000 0000 0000 uuuu uuuu PRODH 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu PRODL 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu INTCON 242 442 252 452 0000 000x 0000 000u uuuu uuuu(1) INTCON2 242 442 252 452 1111 -1-1 1111 -1-1 uuuu -u-u(1) INTCON3 242 442 252 452 11-0 0-00 11-0 0-00 uu-u u-uu(1) INDF0 242 442 252 452 N/A N/A N/A POSTINC0 242 442 252 452 N/A N/A N/A POSTDEC0 242 442 252 452 N/A N/A N/A PREINC0 242 442 252 452 N/A N/A N/A PLUSW0 242 442 252 452 N/A N/A N/A FSR0H 242 442 252 452 ---- xxxx ---- uuuu ---- uuuu FSR0L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu WREG 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu INDF1 242 442 252 452 N/A N/A N/A POSTINC1 242 442 252 452 N/A N/A N/A POSTDEC1 242 442 252 452 N/A N/A N/A PREINC1 242 442 252 452 N/A N/A N/A PLUSW1 242 442 252 452 N/A N/A N/A Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read ’0’. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’. © 2006 Microchip Technology Inc. DS39564C-page 29 PIC18FXX2 FSR1H 242 442 252 452 ---- xxxx ---- uuuu ---- uuuu FSR1L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu BSR 242 442 252 452 ---- 0000 ---- 0000 ---- uuuu INDF2 242 442 252 452 N/A N/A N/A POSTINC2 242 442 252 452 N/A N/A N/A POSTDEC2 242 442 252 452 N/A N/A N/A PREINC2 242 442 252 452 N/A N/A N/A PLUSW2 242 442 252 452 N/A N/A N/A FSR2H 242 442 252 452 ---- xxxx ---- uuuu ---- uuuu FSR2L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu STATUS 242 442 252 452 ---x xxxx ---u uuuu ---u uuuu TMR0H 242 442 252 452 0000 0000 uuuu uuuu uuuu uuuu TMR0L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu T0CON 242 442 252 452 1111 1111 1111 1111 uuuu uuuu OSCCON 242 442 252 452 ---- ---0 ---- ---0 ---- ---u LVDCON 242 442 252 452 --00 0101 --00 0101 --uu uuuu WDTCON 242 442 252 452 ---- ---0 ---- ---0 ---- ---u RCON(4) 242 442 252 452 0--q 11qq 0--q qquu u--u qquu TMR1H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu TMR1L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu T1CON 242 442 252 452 0-00 0000 u-uu uuuu u-uu uuuu TMR2 242 442 252 452 0000 0000 0000 0000 uuuu uuuu PR2 242 442 252 452 1111 1111 1111 1111 1111 1111 T2CON 242 442 252 452 -000 0000 -000 0000 -uuu uuuu SSPBUF 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu SSPADD 242 442 252 452 0000 0000 0000 0000 uuuu uuuu SSPSTAT 242 442 252 452 0000 0000 0000 0000 uuuu uuuu SSPCON1 242 442 252 452 0000 0000 0000 0000 uuuu uuuu SSPCON2 242 442 252 452 0000 0000 0000 0000 uuuu uuuu TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read ’0’. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’. PIC18FXX2 DS39564C-page 30 © 2006 Microchip Technology Inc. ADRESH 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu ADRESL 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu ADCON0 242 442 252 452 0000 00-0 0000 00-0 uuuu uu-u ADCON1 242 442 252 452 00-- 0000 00-- 0000 uu-- uuuu CCPR1H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu CCPR1L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu CCP1CON 242 442 252 452 --00 0000 --00 0000 --uu uuuu CCPR2H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu CCPR2L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu CCP2CON 242 442 252 452 --00 0000 --00 0000 --uu uuuu TMR3H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu TMR3L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu T3CON 242 442 252 452 0000 0000 uuuu uuuu uuuu uuuu SPBRG 242 442 252 452 0000 0000 0000 0000 uuuu uuuu RCREG 242 442 252 452 0000 0000 0000 0000 uuuu uuuu TXREG 242 442 252 452 0000 0000 0000 0000 uuuu uuuu TXSTA 242 442 252 452 0000 -010 0000 -010 uuuu -uuu RCSTA 242 442 252 452 0000 000x 0000 000x uuuu uuuu EEADR 242 442 252 452 0000 0000 0000 0000 uuuu uuuu EEDATA 242 442 252 452 0000 0000 0000 0000 uuuu uuuu EECON1 242 442 252 452 xx-0 x000 uu-0 u000 uu-0 u000 EECON2 242 442 252 452 ---- ---- ---- ---- ---- ---- TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read ’0’. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’. © 2006 Microchip Technology Inc. DS39564C-page 31 PIC18FXX2 IPR2 242 442 252 452 ---1 1111 ---1 1111 ---u uuuu PIR2 242 442 252 452 ---0 0000 ---0 0000 ---u uuuu(1) PIE2 242 442 252 452 ---0 0000 ---0 0000 ---u uuuu IPR1 242 442 252 452 1111 1111 1111 1111 uuuu uuuu 242 442 252 452 -111 1111 -111 1111 -uuu uuuu PIR1 242 442 252 452 0000 0000 0000 0000 uuuu uuuu(1) 242 442 252 452 -000 0000 -000 0000 -uuu uuuu(1) PIE1 242 442 252 452 0000 0000 0000 0000 uuuu uuuu 242 442 252 452 -000 0000 -000 0000 -uuu uuuu TRISE 242 442 252 452 0000 -111 0000 -111 uuuu -uuu TRISD 242 442 252 452 1111 1111 1111 1111 uuuu uuuu TRISC 242 442 252 452 1111 1111 1111 1111 uuuu uuuu TRISB 242 442 252 452 1111 1111 1111 1111 uuuu uuuu TRISA(5,6) 242 442 252 452 -111 1111(5) -111 1111(5) -uuu uuuu(5) LATE 242 442 252 452 ---- -xxx ---- -uuu ---- -uuu LATD 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu LATC 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu LATB 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu LATA(5,6) 242 442 252 452 -xxx xxxx(5) -uuu uuuu(5) -uuu uuuu(5) PORTE 242 442 252 452 ---- -000 ---- -000 ---- -uuu PORTD 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu PORTC 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu PORTB 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu PORTA(5,6) 242 442 252 452 -x0x 0000(5) -u0u 0000(5) -uuu uuuu(5) TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read ’0’. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’. PIC18FXX2 DS39564C-page 32 © 2006 Microchip Technology Inc. FIGURE 3-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD) FIGURE 3-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 FIGURE 3-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TPWRT TOST VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TPWRT TOST© 2006 Microchip Technology Inc. DS39564C-page 33 PIC18FXX2 FIGURE 3-6: SLOW RISE TIME (MCLR TIED TO VDD) FIGURE 3-7: TIME-OUT SEQUENCE ON POR W/ PLL ENABLED (MCLR TIED TO VDD) VDD MCLR INTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET 0V 1V 5V TPWRT TOST TPWRT TOST VDD MCLR IINTERNAL POR PWRT TIME-OUT OST TIME-OUT INTERNAL RESET PLL TIME-OUT TPLL Note: TOST = 1024 clock cycles. TPLL ≈ 2 ms max. First three stages of the PWRT timer.PIC18FXX2 DS39564C-page 34 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 35 PIC18FXX2 4.0 MEMORY ORGANIZATION There are three memory blocks in Enhanced MCU devices. These memory blocks are: • Program Memory • Data RAM • Data EEPROM Data and program memory use separate busses, which allows for concurrent access of these blocks. Additional detailed information for FLASH program memory and Data EEPROM is provided in Section 5.0 and Section 6.0, respectively. 4.1 Program Memory Organization A 21-bit program counter is capable of addressing the 2-Mbyte program memory space. Accessing a location between the physically implemented memory and the 2-Mbyte address will cause a read of all ’0’s (a NOP instruction). The PIC18F252 and PIC18F452 each have 32 Kbytes of FLASH memory, while the PIC18F242 and PIC18F442 have 16 Kbytes of FLASH. This means that PIC18FX52 devices can store up to 16K of single word instructions, and PIC18FX42 devices can store up to 8K of single word instructions. The RESET vector address is at 0000h and the interrupt vector addresses are at 0008h and 0018h. Figure 4-1 shows the Program Memory Map for PIC18F242/442 devices and Figure 4-2 shows the Program Memory Map for PIC18F252/452 devices.PIC18FXX2 DS39564C-page 36 © 2006 Microchip Technology Inc. FIGURE 4-1: PROGRAM MEMORY MAP AND STACK FOR PIC18F442/242 FIGURE 4-2: PROGRAM MEMORY MAP AND STACK FOR PIC18F452/252 PC<20:0> Stack Level 1 • Stack Level 31 RESET Vector Low Priority Interrupt Vector • • CALL,RCALL,RETURN RETFIE,RETLW 21 0000h 0018h On-Chip Program Memory High Priority Interrupt Vector 0008h User Memory Space 1FFFFFh 4000h 3FFFh Read '0' 200000h PC<20:0> Stack Level 1 • Stack Level 31 RESET Vector Low Priority Interrupt Vector • • CALL,RCALL,RETURN RETFIE,RETLW 21 0000h 0018h 8000h 7FFFh On-Chip Program Memory High Priority Interrupt Vector 0008h User Memory Space Read '0' 1FFFFFh 200000h© 2006 Microchip Technology Inc. DS39564C-page 37 PIC18FXX2 4.2 Return Address Stack The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC (Program Counter) is pushed onto the stack when a CALL or RCALL instruction is executed, or an interrupt is acknowledged. The PC value is pulled off the stack on a RETURN, RETLW or a RETFIE instruction. PCLATU and PCLATH are not affected by any of the RETURN or CALL instructions. The stack operates as a 31-word by 21-bit RAM and a 5-bit stack pointer, with the stack pointer initialized to 00000b after all RESETS. There is no RAM associated with stack pointer 00000b. This is only a RESET value. During a CALL type instruction, causing a push onto the stack, the stack pointer is first incremented and the RAM location pointed to by the stack pointer is written with the contents of the PC. During a RETURN type instruction, causing a pop from the stack, the contents of the RAM location pointed to by the STKPTR are transferred to the PC and then the stack pointer is decremented. The stack space is not part of either program or data space. The stack pointer is readable and writable, and the address on the top of the stack is readable and writable through SFR registers. Data can also be pushed to, or popped from, the stack using the top-of-stack SFRs. Status bits indicate if the stack pointer is at, or beyond the 31 levels provided. 4.2.1 TOP-OF-STACK ACCESS The top of the stack is readable and writable. Three register locations, TOSU, TOSH and TOSL hold the contents of the stack location pointed to by the STKPTR register. This allows users to implement a software stack if necessary. After a CALL, RCALL or interrupt, the software can read the pushed value by reading the TOSU, TOSH and TOSL registers. These values can be placed on a user defined software stack. At return time, the software can replace the TOSU, TOSH and TOSL and do a return. The user must disable the global interrupt enable bits during this time to prevent inadvertent stack operations. 4.2.2 RETURN STACK POINTER (STKPTR) The STKPTR register contains the stack pointer value, the STKFUL (stack full) status bit, and the STKUNF (stack underflow) status bits. Register 4-1 shows the STKPTR register. The value of the stack pointer can be 0 through 31. The stack pointer increments when values are pushed onto the stack and decrements when values are popped off the stack. At RESET, the stack pointer value will be 0. The user may read and write the stack pointer value. This feature can be used by a Real Time Operating System for return stack maintenance. After the PC is pushed onto the stack 31 times (without popping any values off the stack), the STKFUL bit is set. The STKFUL bit can only be cleared in software or by a POR. The action that takes place when the stack becomes full depends on the state of the STVREN (Stack Overflow Reset Enable) configuration bit. Refer to Section 20.0 for a description of the device configuration bits. If STVREN is set (default), the 31st push will push the (PC + 2) value onto the stack, set the STKFUL bit, and reset the device. The STKFUL bit will remain set and the stack pointer will be set to ‘0’. If STVREN is cleared, the STKFUL bit will be set on the 31st push and the stack pointer will increment to 31. Any additional pushes will not overwrite the 31st push, and STKPTR will remain at 31. When the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the PC and sets the STKUNF bit, while the stack pointer remains at 0. The STKUNF bit will remain set until cleared in software or a POR occurs. Note: Returning a value of zero to the PC on an underflow has the effect of vectoring the program to the RESET vector, where the stack conditions can be verified and appropriate actions can be taken.PIC18FXX2 DS39564C-page 38 © 2006 Microchip Technology Inc. REGISTER 4-1: STKPTR REGISTER FIGURE 4-3: RETURN ADDRESS STACK AND ASSOCIATED REGISTERS 4.2.3 PUSH AND POP INSTRUCTIONS Since the Top-of-Stack (TOS) is readable and writable, the ability to push values onto the stack and pull values off the stack without disturbing normal program execution is a desirable option. To push the current PC value onto the stack, a PUSH instruction can be executed. This will increment the stack pointer and load the current PC value onto the stack. TOSU, TOSH and TOSL can then be modified to place a return address on the stack. The ability to pull the TOS value off of the stack and replace it with the value that was previously pushed onto the stack, without disturbing normal execution, is achieved by using the POP instruction. The POP instruction discards the current TOS by decrementing the stack pointer. The previous value pushed onto the stack then becomes the TOS value. 4.2.4 STACK FULL/UNDERFLOW RESETS These resets are enabled by programming the STVREN configuration bit. When the STVREN bit is disabled, a full or underflow condition will set the appropriate STKFUL or STKUNF bit, but not cause a device RESET. When the STVREN bit is enabled, a full or underflow will set the appropriate STKFUL or STKUNF bit and then cause a device RESET. The STKFUL or STKUNF bits are only cleared by the user software or a POR Reset. R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 STKOVF STKUNF — SP4 SP3 SP2 SP1 SP0 bit 7 bit 0 bit 7(1) STKOVF: Stack Full Flag bit 1 = Stack became full or overflowed 0 = Stack has not become full or overflowed bit 6(1) STKUNF: Stack Underflow Flag bit 1 = Stack underflow occurred 0 = Stack underflow did not occur bit 5 Unimplemented: Read as '0' bit 4-0 SP4:SP0: Stack Pointer Location bits Note 1: Bit 7 and bit 6 can only be cleared in user software or by a POR. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown 00011 0x001A34 11111 11110 11101 00010 00001 00000 00010 Return Address Stack Top of Stack 0x000D58 TOSU TOSH TOSL 0x00 0x1A 0x34 STKPTR<4:0>© 2006 Microchip Technology Inc. DS39564C-page 39 PIC18FXX2 4.3 Fast Register Stack A “fast interrupt return” option is available for interrupts. A Fast Register Stack is provided for the STATUS, WREG and BSR registers and are only one in depth. The stack is not readable or writable and is loaded with the current value of the corresponding register when the processor vectors for an interrupt. The values in the registers are then loaded back into the working registers, if the FAST RETURN instruction is used to return from the interrupt. A low or high priority interrupt source will push values into the stack registers. If both low and high priority interrupts are enabled, the stack registers cannot be used reliably for low priority interrupts. If a high priority interrupt occurs while servicing a low priority interrupt, the stack register values stored by the low priority interrupt will be overwritten. If high priority interrupts are not disabled during low priority interrupts, users must save the key registers in software during a low priority interrupt. If no interrupts are used, the fast register stack can be used to restore the STATUS, WREG and BSR registers at the end of a subroutine call. To use the fast register stack for a subroutine call, a FAST CALL instruction must be executed. Example 4-1 shows a source code example that uses the fast register stack. EXAMPLE 4-1: FAST REGISTER STACK CODE EXAMPLE 4.4 PCL, PCLATH and PCLATU The program counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21-bits wide. The low byte is called the PCL register. This register is readable and writable. The high byte is called the PCH register. This register contains the PC<15:8> bits and is not directly readable or writable. Updates to the PCH register may be performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits and is not directly readable or writable. Updates to the PCU register may be performed through the PCLATU register. The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the LSB of PCL is fixed to a value of ’0’. The PC increments by 2 to address sequential instructions in the program memory. The CALL, RCALL, GOTO and program branch instructions write to the program counter directly. For these instructions, the contents of PCLATH and PCLATU are not transferred to the program counter. The contents of PCLATH and PCLATU will be transferred to the program counter by an operation that writes PCL. Similarly, the upper two bytes of the program counter will be transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 4.8.1). 4.5 Clocking Scheme/Instruction Cycle The clock input (from OSC1) is internally divided by four to generate four non-overlapping quadrature clocks, namely Q1, Q2, Q3 and Q4. Internally, the program counter (PC) is incremented every Q1, the instruction is fetched from the program memory and latched into the instruction register in Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 4-4. FIGURE 4-4: CLOCK/INSTRUCTION CYCLE CALL SUB1, FAST ;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK • • SUB1 • • • RETURN FAST ;RESTORE VALUES SAVED ;IN FAST REGISTER STACK Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Q3 Q4 PC OSC2/CLKO (RC mode) PC PC+2 PC+4 Fetch INST (PC) Execute INST (PC-2) Fetch INST (PC+2) Execute INST (PC) Fetch INST (PC+4) Execute INST (PC+2) Internal Phase ClockPIC18FXX2 DS39564C-page 40 © 2006 Microchip Technology Inc. 4.6 Instruction Flow/Pipelining An “Instruction Cycle” consists of four Q cycles (Q1, Q2, Q3 and Q4). The instruction fetch and execute are pipelined such that fetch takes one instruction cycle, while decode and execute takes another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g., GOTO) then two cycles are required to complete the instruction (Example 4-2). A fetch cycle begins with the program counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the “Instruction Register” (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3, and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write). EXAMPLE 4-2: INSTRUCTION PIPELINE FLOW 4.7 Instructions in Program Memory The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program memory. The Least Significant Byte of an instruction word is always stored in a program memory location with an even address (LSB =’0’). Figure 4-5 shows an example of how instruction words are stored in the program memory. To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSB will always read ’0’ (see Section 4.4). The CALL and GOTO instructions have an absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, the data contained in the instruction is a word address. The word address is written to PC<20:1>, which accesses the desired byte address in program memory. Instruction #2 in Figure 4-5 shows how the instruction “GOTO 000006h’ is encoded in the program memory. Program branch instructions which encode a relative address offset operate in the same manner. The offset value stored in a branch instruction represents the number of single word instructions that the PC will be offset by. Section 20.0 provides further details of the instruction set. FIGURE 4-5: INSTRUCTIONS IN PROGRAM MEMORY All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction is “flushed” from the pipeline while the new instruction is being fetched and then executed. TCY0 TCY1 TCY2 TCY3 TCY4 TCY5 1. MOVLW 55h Fetch 1 Execute 1 2. MOVWF PORTB Fetch 2 Execute 2 3. BRA SUB_1 Fetch 3 Execute 3 4. BSF PORTA, BIT3 (Forced NOP) Fetch 4 Flush (NOP) 5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1 Word Address LSB = 1 LSB = 0 ↓ Program Memory Byte Locations → 000000h 000002h 000004h 000006h Instruction 1: MOVLW 055h 0Fh 55h 000008h Instruction 2: GOTO 000006h EFh 03h 00000Ah F0h 00h 00000Ch Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh F4h 56h 000010h 000012h 000014h© 2006 Microchip Technology Inc. DS39564C-page 41 PIC18FXX2 4.7.1 TWO-WORD INSTRUCTIONS The PIC18FXX2 devices have four two-word instructions: MOVFF, CALL, GOTO and LFSR. The second word of these instructions has the 4 MSBs set to 1’s and is a special kind of NOP instruction. The lower 12 bits of the second word contain data to be used by the instruction. If the first word of the instruction is executed, the data in the second word is accessed. If the second word of the instruction is executed by itself (first word was skipped), it will execute as a NOP. This action is necessary when the two-word instruction is preceded by a conditional instruction that changes the PC. A program example that demonstrates this concept is shown in Example 4-3. Refer to Section 20.0 for further details of the instruction set. EXAMPLE 4-3: TWO-WORD INSTRUCTIONS 4.8 Lookup Tables Lookup tables are implemented two ways. These are: • Computed GOTO • Table Reads 4.8.1 COMPUTED GOTO A computed GOTO is accomplished by adding an offset to the program counter (ADDWF PCL). A lookup table can be formed with an ADDWF PCL instruction and a group of RETLW 0xnn instructions. WREG is loaded with an offset into the table before executing a call to that table. The first instruction of the called routine is the ADDWF PCL instruction. The next instruction executed will be one of the RETLW 0xnn instructions, that returns the value 0xnn to the calling function. The offset value (value in WREG) specifies the number of bytes that the program counter should advance. In this method, only one data byte may be stored in each instruction location and room on the return address stack is required. 4.8.2 TABLE READS/TABLE WRITES A better method of storing data in program memory allows 2 bytes of data to be stored in each instruction location. Lookup table data may be stored 2 bytes per program word by using table reads and writes. The table pointer (TBLPTR) specifies the byte address and the table latch (TABLAT) contains the data that is read from, or written to program memory. Data is transferred to/from program memory, one byte at a time. A description of the Table Read/Table Write operation is shown in Section 3.0. CASE 1: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; No, execute 2-word instruction 1111 0100 0101 0110 ; 2nd operand holds address of REG2 0010 0100 0000 0000 ADDWF REG3 ; continue code CASE 2: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes 1111 0100 0101 0110 ; 2nd operand becomes NOP 0010 0100 0000 0000 ADDWF REG3 ; continue code Note: The ADDWF PCL instruction does not update PCLATH and PCLATU. A read operation on PCL must be performed to update PCLATH and PCLATU.PIC18FXX2 DS39564C-page 42 © 2006 Microchip Technology Inc. 4.9 Data Memory Organization The data memory is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. Figure 4-6 and Figure 4-7 show the data memory organization for the PIC18FXX2 devices. The data memory map is divided into as many as 16 banks that contain 256 bytes each. The lower 4 bits of the Bank Select Register (BSR<3:0>) select which bank will be accessed. The upper 4 bits for the BSR are not implemented. The data memory contains Special Function Registers (SFR) and General Purpose Registers (GPR). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratch pad operations in the user’s application. The SFRs start at the last location of Bank 15 (0xFFF) and extend downwards. Any remaining space beyond the SFRs in the Bank may be implemented as GPRs. GPRs start at the first location of Bank 0 and grow upwards. Any read of an unimplemented location will read as ’0’s. The entire data memory may be accessed directly or indirectly. Direct addressing may require the use of the BSR register. Indirect addressing requires the use of a File Select Register (FSRn) and a corresponding Indirect File Operand (INDFn). Each FSR holds a 12-bit address value that can be used to access any location in the Data Memory map without banking. The instruction set and architecture allow operations across all banks. This may be accomplished by indirect addressing or by the use of the MOVFF instruction. The MOVFF instruction is a two-word/two-cycle instruction that moves a value from one register to another. To ensure that commonly used registers (SFRs and select GPRs) can be accessed in a single cycle, regardless of the current BSR values, an Access Bank is implemented. A segment of Bank 0 and a segment of Bank 15 comprise the Access RAM. Section 4.10 provides a detailed description of the Access RAM. 4.9.1 GENERAL PURPOSE REGISTER FILE The register file can be accessed either directly or indirectly. Indirect addressing operates using a File Select Register and corresponding Indirect File Operand. The operation of indirect addressing is shown in Section 4.12. Enhanced MCU devices may have banked memory in the GPR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other RESETS. Data RAM is available for use as GPR registers by all instructions. The top half of Bank 15 (0xF80 to 0xFFF) contains SFRs. All other banks of data memory contain GPR registers, starting with Bank 0. 4.9.2 SPECIAL FUNCTION REGISTERS The Special Function Registers (SFRs) are registers used by the CPU and Peripheral Modules for controlling the desired operation of the device. These registers are implemented as static RAM. A list of these registers is given in Table 4-1 and Table 4-2. The SFRs can be classified into two sets; those associated with the “core” function and those related to the peripheral functions. Those registers related to the “core” are described in this section, while those related to the operation of the peripheral features are described in the section of that peripheral feature. The SFRs are typically distributed among the peripherals whose functions they control. The unused SFR locations will be unimplemented and read as '0's. See Table 4-1 for addresses for the SFRs.© 2006 Microchip Technology Inc. DS39564C-page 43 PIC18FXX2 FIGURE 4-6: DATA MEMORY MAP FOR PIC18F242/442 Bank 0 Bank 1 Bank 14 Bank 15 BSR<3:0> Data Memory Map = 0000 = 0001 = 1111 080h 07Fh F80h FFFh 00h 7Fh 80h FFh Access Bank When a = 0, the BSR is ignored and the Access Bank is used. The first 128 bytes are General Purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15). When a = 1, the BSR is used to specify the RAM location that the instruction uses. F7Fh F00h EFFh 1FFh 100h 0FFh 000h Access RAM FFh 00h FFh 00h FFh 00h GPR GPR SFR Unused Access RAM high Access RAM low Bank 3 to 200h Unused = 1110 Read ’00h’ = 0011 (SFRs) GPR 2FFh 300h FFh 00h Bank 2 = 0010PIC18FXX2 DS39564C-page 44 © 2006 Microchip Technology Inc. FIGURE 4-7: DATA MEMORY MAP FOR PIC18F252/452 Bank 0 Bank 1 Bank 14 Bank 15 BSR<3:0> Data Memory Map = 0000 = 0001 = 1110 = 1111 080h 07Fh F80h FFFh 00h 7Fh 80h FFh Access Bank When a = 0, the BSR is ignored and the Access Bank is used. The first 128 bytes are General Purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15). When a = 1, the BSR is used to specify the RAM location that the instruction uses. Bank 4 Bank 3 Bank 2 F7Fh F00h EFFh 3FFh 300h 2FFh 200h 1FFh 100h 0FFh 000h = 0110 = 0101 = 0011 = 0010 Access RAM FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h FFh 00h GPR GPR GPR GPR SFR Unused Access RAM high Access RAM low Bank 5 GPR GPR Bank 6 to 4FFh 400h 5FFh 500h 600h Unused Read ’00h’ = 0100 (SFR’s)© 2006 Microchip Technology Inc. DS39564C-page 45 PIC18FXX2 TABLE 4-1: SPECIAL FUNCTION REGISTER MAP Address Name Address Name Address Name Address Name FFFh TOSU FDFh INDF2(3) FBFh CCPR1H F9Fh IPR1 FFEh TOSH FDEh POSTINC2(3) FBEh CCPR1L F9Eh PIR1 FFDh TOSL FDDh POSTDEC2(3) FBDh CCP1CON F9Dh PIE1 FFCh STKPTR FDCh PREINC2(3) FBCh CCPR2H F9Ch — FFBh PCLATU FDBh PLUSW2(3) FBBh CCPR2L F9Bh — FFAh PCLATH FDAh FSR2H FBAh CCP2CON F9Ah — FF9h PCL FD9h FSR2L FB9h — F99h — FF8h TBLPTRU FD8h STATUS FB8h — F98h — FF7h TBLPTRH FD7h TMR0H FB7h — F97h — FF6h TBLPTRL FD6h TMR0L FB6h — F96h TRISE(2) FF5h TABLAT FD5h T0CON FB5h — F95h TRISD(2) FF4h PRODH FD4h — FB4h — F94h TRISC FF3h PRODL FD3h OSCCON FB3h TMR3H F93h TRISB FF2h INTCON FD2h LVDCON FB2h TMR3L F92h TRISA FF1h INTCON2 FD1h WDTCON FB1h T3CON F91h — FF0h INTCON3 FD0h RCON FB0h — F90h — FEFh INDF0(3) FCFh TMR1H FAFh SPBRG F8Fh — FEEh POSTINC0(3) FCEh TMR1L FAEh RCREG F8Eh — FEDh POSTDEC0(3) FCDh T1CON FADh TXREG F8Dh LATE(2) FECh PREINC0(3) FCCh TMR2 FACh TXSTA F8Ch LATD(2) FEBh PLUSW0(3) FCBh PR2 FABh RCSTA F8Bh LATC FEAh FSR0H FCAh T2CON FAAh — F8Ah LATB FE9h FSR0L FC9h SSPBUF FA9h EEADR F89h LATA FE8h WREG FC8h SSPADD FA8h EEDATA F88h — FE7h INDF1(3) FC7h SSPSTAT FA7h EECON2 F87h — FE6h POSTINC1(3) FC6h SSPCON1 FA6h EECON1 F86h — FE5h POSTDEC1(3) FC5h SSPCON2 FA5h — F85h — FE4h PREINC1(3) FC4h ADRESH FA4h — F84h PORTE(2) FE3h PLUSW1(3) FC3h ADRESL FA3h — F83h PORTD(2) FE2h FSR1H FC2h ADCON0 FA2h IPR2 F82h PORTC FE1h FSR1L FC1h ADCON1 FA1h PIR2 F81h PORTB FE0h BSR FC0h — FA0h PIE2 F80h PORTA Note 1: Unimplemented registers are read as ’0’. 2: This register is not available on PIC18F2X2 devices. 3: This is not a physical register.PIC18FXX2 DS39564C-page 46 © 2006 Microchip Technology Inc. TABLE 4-2: REGISTER FILE SUMMARY File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: TOSU — — — Top-of-Stack upper Byte (TOS<20:16>) ---0 0000 37 TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 37 TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 37 STKPTR STKFUL STKUNF — Return Stack Pointer 00-0 0000 38 PCLATU — — — Holding Register for PC<20:16> ---0 0000 39 PCLATH Holding Register for PC<15:8> 0000 0000 39 PCL PC Low Byte (PC<7:0>) 0000 0000 39 TBLPTRU — — bit21(2) Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 58 TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 58 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 58 TABLAT Program Memory Table Latch 0000 0000 58 PRODH Product Register High Byte xxxx xxxx 71 PRODL Product Register Low Byte xxxx xxxx 71 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 75 INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP 1111 -1-1 76 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 77 INDF0 Uses contents of FSR0 to address data memory - value of FSR0 not changed (not a physical register) n/a 50 POSTINC0 Uses contents of FSR0 to address data memory - value of FSR0 post-incremented (not a physical register) n/a 50 POSTDEC0 Uses contents of FSR0 to address data memory - value of FSR0 post-decremented (not a physical register) n/a 50 PREINC0 Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register) n/a 50 PLUSW0 Uses contents of FSR0 to address data memory - value of FSR0 (not a physical register). Offset by value in WREG. n/a 50 FSR0H — — — — Indirect Data Memory Address Pointer 0 High Byte ---- 0000 50 FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 50 WREG Working Register xxxx xxxx n/a INDF1 Uses contents of FSR1 to address data memory - value of FSR1 not changed (not a physical register) n/a 50 POSTINC1 Uses contents of FSR1 to address data memory - value of FSR1 post-incremented (not a physical register) n/a 50 POSTDEC1 Uses contents of FSR1 to address data memory - value of FSR1 post-decremented (not a physical register) n/a 50 PREINC1 Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register) n/a 50 PLUSW1 Uses contents of FSR1 to address data memory - value of FSR1 (not a physical register). Offset by value in WREG. n/a 50 FSR1H — — — — Indirect Data Memory Address Pointer 1 High Byte ---- 0000 50 FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 50 BSR — — — — Bank Select Register ---- 0000 49 INDF2 Uses contents of FSR2 to address data memory - value of FSR2 not changed (not a physical register) n/a 50 POSTINC2 Uses contents of FSR2 to address data memory - value of FSR2 post-incremented (not a physical register) n/a 50 POSTDEC2 Uses contents of FSR2 to address data memory - value of FSR2 post-decremented (not a physical register) n/a 50 PREINC2 Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register) n/a 50 PLUSW2 Uses contents of FSR2 to address data memory - value of FSR2 (not a physical register). Offset by value in WREG. n/a 50 FSR2H — — — — Indirect Data Memory Address Pointer 2 High Byte ---- 0000 50 FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 50 STATUS — — — N OV Z DC C ---x xxxx 52 TMR0H Timer0 Register High Byte 0000 0000 105 TMR0L Timer0 Register Low Byte xxxx xxxx 105 T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 103 Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition Note 1: RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes. 2: Bit 21 of the TBLPTRU allows access to the device configuration bits. 3: These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.© 2006 Microchip Technology Inc. DS39564C-page 47 PIC18FXX2 OSCCON — — — — — — — SCS ---- ---0 21 LVDCON — — IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 --00 0101 191 WDTCON — — — — — — — SWDTE ---- ---0 203 RCON IPEN — — RI TO PD POR BOR 0--1 11qq 53, 28, 84 TMR1H Timer1 Register High Byte xxxx xxxx 107 TMR1L Timer1 Register Low Byte xxxx xxxx 107 T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 107 TMR2 Timer2 Register 0000 0000 111 PR2 Timer2 Period Register 1111 1111 112 T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 111 SSPBUF SSP Receive Buffer/Transmit Register xxxx xxxx 125 SSPADD SSP Address Register in I2C Slave mode. SSP Baud Rate Reload Register in I2C Master mode. 0000 0000 134 SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 126 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 127 SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 137 ADRESH A/D Result Register High Byte xxxx xxxx 187,188 ADRESL A/D Result Register Low Byte xxxx xxxx 187,188 ADCON0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE — ADON 0000 00-0 181 ADCON1 ADFM ADCS2 — — PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 182 CCPR1H Capture/Compare/PWM Register1 High Byte xxxx xxxx 121, 123 CCPR1L Capture/Compare/PWM Register1 Low Byte xxxx xxxx 121, 123 CCP1CON — — DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 117 CCPR2H Capture/Compare/PWM Register2 High Byte xxxx xxxx 121, 123 CCPR2L Capture/Compare/PWM Register2 Low Byte xxxx xxxx 121, 123 CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 117 TMR3H Timer3 Register High Byte xxxx xxxx 113 TMR3L Timer3 Register Low Byte xxxx xxxx 113 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 113 SPBRG USART1 Baud Rate Generator 0000 0000 168 RCREG USART1 Receive Register 0000 0000 175, 178, 180 TXREG USART1 Transmit Register 0000 0000 173, 176, 179 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 166 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 167 EEADR Data EEPROM Address Register 0000 0000 65, 69 EEDATA Data EEPROM Data Register 0000 0000 69 EECON2 Data EEPROM Control Register 2 (not a physical register) ---- ---- 65, 69 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 66 TABLE 4-2: REGISTER FILE SUMMARY (CONTINUED) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition Note 1: RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes. 2: Bit 21 of the TBLPTRU allows access to the device configuration bits. 3: These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.PIC18FXX2 DS39564C-page 48 © 2006 Microchip Technology Inc. IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 83 PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 79 PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 81 IPR1 PSPIP(3) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 1111 1111 82 PIR1 PSPIF(3) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 78 PIE1 PSPIE(3) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 80 TRISE(3) IBF OBF IBOV PSPMODE — Data Direction bits for PORTE 0000 -111 98 TRISD(3) Data Direction Control Register for PORTD 1111 1111 96 TRISC Data Direction Control Register for PORTC 1111 1111 93 TRISB Data Direction Control Register for PORTB 1111 1111 90 TRISA — TRISA6(1) Data Direction Control Register for PORTA -111 1111 87 LATE(3) — — — — — Read PORTE Data Latch, Write PORTE Data Latch ---- -xxx 99 LATD(3) Read PORTD Data Latch, Write PORTD Data Latch xxxx xxxx 95 LATC Read PORTC Data Latch, Write PORTC Data Latch xxxx xxxx 93 LATB Read PORTB Data Latch, Write PORTB Data Latch xxxx xxxx 90 LATA — LATA6(1) Read PORTA Data Latch, Write PORTA Data Latch(1) -xxx xxxx 87 PORTE(3) Read PORTE pins, Write PORTE Data Latch ---- -000 99 PORTD(3) Read PORTD pins, Write PORTD Data Latch xxxx xxxx 95 PORTC Read PORTC pins, Write PORTC Data Latch xxxx xxxx 93 PORTB Read PORTB pins, Write PORTB Data Latch xxxx xxxx 90 PORTA — RA6(1) Read PORTA pins, Write PORTA Data Latch(1) -x0x 0000 87 TABLE 4-2: REGISTER FILE SUMMARY (CONTINUED) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition Note 1: RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes. 2: Bit 21 of the TBLPTRU allows access to the device configuration bits. 3: These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.© 2006 Microchip Technology Inc. DS39564C-page 49 PIC18FXX2 4.10 Access Bank The Access Bank is an architectural enhancement which is very useful for C compiler code optimization. The techniques used by the C compiler may also be useful for programs written in assembly. This data memory region can be used for: • Intermediate computational values • Local variables of subroutines • Faster context saving/switching of variables • Common variables • Faster evaluation/control of SFRs (no banking) The Access Bank is comprised of the upper 128 bytes in Bank 15 (SFRs) and the lower 128 bytes in Bank 0. These two sections will be referred to as Access RAM High and Access RAM Low, respectively. Figure 4-6 and Figure 4-7 indicate the Access RAM areas. A bit in the instruction word specifies if the operation is to occur in the bank specified by the BSR register or in the Access Bank. This bit is denoted by the ’a’ bit (for access bit). When forced in the Access Bank (a = 0), the last address in Access RAM Low is followed by the first address in Access RAM High. Access RAM High maps the Special Function registers, so that these registers can be accessed without any software overhead. This is useful for testing status flags and modifying control bits. 4.11 Bank Select Register (BSR) The need for a large general purpose memory space dictates a RAM banking scheme. The data memory is partitioned into sixteen banks. When using direct addressing, the BSR should be configured for the desired bank. BSR<3:0> holds the upper 4 bits of the 12-bit RAM address. The BSR<7:4> bits will always read ’0’s, and writes will have no effect. A MOVLB instruction has been provided in the instruction set to assist in selecting banks. If the currently selected bank is not implemented, any read will return all '0's and all writes are ignored. The STATUS register bits will be set/cleared as appropriate for the instruction performed. Each Bank extends up to FFh (256 bytes). All data memory is implemented as static RAM. A MOVFF instruction ignores the BSR, since the 12-bit addresses are embedded into the instruction word. Section 4.12 provides a description of indirect addressing, which allows linear addressing of the entire RAM space. FIGURE 4-8: DIRECT ADDRESSING Note 1: For register file map detail, see Table 4-1. 2: The access bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the registers of the Access Bank. 3: The MOVFF instruction embeds the entire 12-bit address in the instruction. Data Memory(1) Direct Addressing Bank Select(2) Location Select(3) BSR<3:0> 7 From Opcode 0 (3) 00h 01h 0Eh 0Fh Bank 0 Bank 1 Bank 14 Bank 15 1FFh 100h 0FFh 000h EFFh E00h FFFh F00hPIC18FXX2 DS39564C-page 50 © 2006 Microchip Technology Inc. 4.12 Indirect Addressing, INDF and FSR Registers Indirect addressing is a mode of addressing data memory, where the data memory address in the instruction is not fixed. An FSR register is used as a pointer to the data memory location that is to be read or written. Since this pointer is in RAM, the contents can be modified by the program. This can be useful for data tables in the data memory and for software stacks. Figure 4-9 shows the operation of indirect addressing. This shows the moving of the value to the data memory address specified by the value of the FSR register. Indirect addressing is possible by using one of the INDF registers. Any instruction using the INDF register actually accesses the register pointed to by the File Select Register, FSR. Reading the INDF register itself, indirectly (FSR = 0), will read 00h. Writing to the INDF register indirectly, results in a no operation. The FSR register contains a 12-bit address, which is shown in Figure 4-10. The INDFn register is not a physical register. Addressing INDFn actually addresses the register whose address is contained in the FSRn register (FSRn is a pointer). This is indirect addressing. Example 4-4 shows a simple use of indirect addressing to clear the RAM in Bank1 (locations 100h-1FFh) in a minimum number of instructions. EXAMPLE 4-4: HOW TO CLEAR RAM (BANK1) USING INDIRECT ADDRESSING There are three indirect addressing registers. To address the entire data memory space (4096 bytes), these registers are 12-bit wide. To store the 12-bits of addressing information, two 8-bit registers are required. These indirect addressing registers are: 1. FSR0: composed of FSR0H:FSR0L 2. FSR1: composed of FSR1H:FSR1L 3. FSR2: composed of FSR2H:FSR2L In addition, there are registers INDF0, INDF1 and INDF2, which are not physically implemented. Reading or writing to these registers activates indirect addressing, with the value in the corresponding FSR register being the address of the data. If an instruction writes a value to INDF0, the value will be written to the address pointed to by FSR0H:FSR0L. A read from INDF1 reads the data from the address pointed to by FSR1H:FSR1L. INDFn can be used in code anywhere an operand can be used. If INDF0, INDF1 or INDF2 are read indirectly via an FSR, all '0's are read (zero bit is set). Similarly, if INDF0, INDF1 or INDF2 are written to indirectly, the operation will be equivalent to a NOP instruction and the STATUS bits are not affected. 4.12.1 INDIRECT ADDRESSING OPERATION Each FSR register has an INDF register associated with it, plus four additional register addresses. Performing an operation on one of these five registers determines how the FSR will be modified during indirect addressing. When data access is done to one of the five INDFn locations, the address selected will configure the FSRn register to: • Do nothing to FSRn after an indirect access (no change) - INDFn • Auto-decrement FSRn after an indirect access (post-decrement) - POSTDECn • Auto-increment FSRn after an indirect access (post-increment) - POSTINCn • Auto-increment FSRn before an indirect access (pre-increment) - PREINCn • Use the value in the WREG register as an offset to FSRn. Do not modify the value of the WREG or the FSRn register after an indirect access (no change) - PLUSWn When using the auto-increment or auto-decrement features, the effect on the FSR is not reflected in the STATUS register. For example, if the indirect address causes the FSR to equal '0', the Z bit will not be set. Incrementing or decrementing an FSR affects all 12 bits. That is, when FSRnL overflows from an increment, FSRnH will be incremented automatically. Adding these features allows the FSRn to be used as a stack pointer, in addition to its uses for table operations in data memory. Each FSR has an address associated with it that performs an indexed indirect access. When a data access to this INDFn location (PLUSWn) occurs, the FSRn is configured to add the signed value in the WREG register and the value in FSR to form the address before an indirect access. The FSR value is not changed. If an FSR register contains a value that points to one of the INDFn, an indirect read will read 00h (zero bit is set), while an indirect write will be equivalent to a NOP (STATUS bits are not affected). If an indirect addressing operation is done where the target address is an FSRnH or FSRnL register, the write operation will dominate over the pre- or post-increment/decrement functions. LFSR FSR0 ,0x100 ; NEXT CLRF POSTINC0 ; Clear INDF ; register and ; inc pointer BTFSS FSR0H, 1 ; All done with ; Bank1? GOTO NEXT ; NO, clear next CONTINUE ; YES, continue © 2006 Microchip Technology Inc. DS39564C-page 51 PIC18FXX2 FIGURE 4-9: INDIRECT ADDRESSING OPERATION FIGURE 4-10: INDIRECT ADDRESSING Opcode Address File Address = access of an indirect addressing register FSR Instruction Executed Instruction Fetched RAM Opcode File 12 12 12 BSR<3:0> 4 8 0h FFFh Note 1: For register file map detail, see Table 4-1. Data Memory(1) Indirect Addressing 11 FSR Register 0 0FFFh 0000h Location SelectPIC18FXX2 DS39564C-page 52 © 2006 Microchip Technology Inc. 4.13 STATUS Register The STATUS register, shown in Register 4-2, contains the arithmetic status of the ALU. The STATUS register can be the destination for any instruction, as with any other register. If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV, or N bits, then the write to these five bits is disabled. These bits are set or cleared according to the device logic. Therefore, the result of an instruction with the STATUS register as destination may be different than intended. For example, CLRF STATUS will clear the upper three bits and set the Z bit. This leaves the STATUS register as 000u u1uu (where u = unchanged). It is recommended, therefore, that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the STATUS register, because these instructions do not affect the Z, C, DC, OV, or N bits from the STATUS register. For other instructions not affecting any status bits, see Table 20-2. REGISTER 4-2: STATUS REGISTER Note: The C and DC bits operate as a borrow and digit borrow bit respectively, in subtraction. U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x — — — N OV Z DC C bit 7 bit 0 bit 7-5 Unimplemented: Read as '0' bit 4 N: Negative bit This bit is used for signed arithmetic (2’s complement). It indicates whether the result was negative (ALU MSB = 1). 1 = Result was negative 0 = Result was positive bit 3 OV: Overflow bit This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit magnitude, which causes the sign bit (bit7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred bit 2 Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero bit 1 DC: Digit carry/borrow bit For ADDWF, ADDLW, SUBLW, and SUBWF instructions 1 = A carry-out from the 4th low order bit of the result occurred 0 = No carry-out from the 4th low order bit of the result Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two’s complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the bit 4 or bit 3 of the source register. bit 0 C: Carry/borrow bit For ADDWF, ADDLW, SUBLW, and SUBWF instructions 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two’s complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low order bit of the source register. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 53 PIC18FXX2 4.14 RCON Register The Reset Control (RCON) register contains flag bits that allow differentiation between the sources of a device RESET. These flags include the TO, PD, POR, BOR and RI bits. This register is readable and writable. REGISTER 4-3: RCON REGISTER Note 1: If the BOREN configuration bit is set (Brown-out Reset enabled), the BOR bit is ’1’ on a Power-on Reset. After a Brownout Reset has occurred, the BOR bit will be cleared, and must be set by firmware to indicate the occurrence of the next Brown-out Reset. 2: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent Power-on Resets may be detected. R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN — — RI TO PD POR BOR bit 7 bit 0 bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (16CXXX Compatibility mode) bit 6-5 Unimplemented: Read as '0' bit 4 RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed 0 = The RESET instruction was executed causing a device RESET (must be set in software after a Brown-out Reset occurs) bit 3 TO: Watchdog Time-out Flag bit 1 = After power-up, CLRWDT instruction, or SLEEP instruction 0 = A WDT time-out occurred bit 2 PD: Power-down Detection Flag bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction bit 1 POR: Power-on Reset Status bit 1 = A Power-on Reset has not occurred 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) bit 0 BOR: Brown-out Reset Status bit 1 = A Brown-out Reset has not occurred 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 54 © 2006 Microchip Technology Inc. NOTES: © 2006 Microchip Technology Inc. DS39564C-page 55 PIC18FXX2 5.0 FLASH PROGRAM MEMORY The FLASH Program Memory is readable, writable, and erasable during normal operation over the entire VDD range. A read from program memory is executed on one byte at a time. A write to program memory is executed on blocks of 8 bytes at a time. Program memory is erased in blocks of 64 bytes at a time. A bulk erase operation may not be issued from user code. Writing or erasing program memory will cease instruction fetches until the operation is complete. The program memory cannot be accessed during the write or erase, therefore, code cannot execute. An internal programming timer terminates program memory writes and erases. A value written to program memory does not need to be a valid instruction. Executing a program memory location that forms an invalid instruction results in a NOP. 5.1 Table Reads and Table Writes In order to read and write program memory, there are two operations that allow the processor to move bytes between the program memory space and the data RAM: • Table Read (TBLRD) • Table Write (TBLWT) The program memory space is 16-bits wide, while the data RAM space is 8-bits wide. Table Reads and Table Writes move data between these two memory spaces through an 8-bit register (TABLAT). Table Read operations retrieve data from program memory and places it into the data RAM space. Figure 5-1 shows the operation of a Table Read with program memory and data RAM. Table Write operations store data from the data memory space into holding registers in program memory. The procedure to write the contents of the holding registers into program memory is detailed in Section 5.5, '”Writing to FLASH Program Memory”. Figure 5-2 shows the operation of a Table Write with program memory and data RAM. Table operations work with byte entities. A table block containing data, rather than program instructions, is not required to be word aligned. Therefore, a table block can start and end at any byte address. If a Table Write is being used to write executable code into program memory, program instructions will need to be word aligned. FIGURE 5-1: TABLE READ OPERATION Table Pointer(1) Table Latch (8-bit) Program Memory TBLPTRH TBLPTRL TABLAT TBLPTRU Instruction: TBLRD* Note 1: Table Pointer points to a byte in program memory. Program Memory (TBLPTR)PIC18FXX2 DS39564C-page 56 © 2006 Microchip Technology Inc. FIGURE 5-2: TABLE WRITE OPERATION 5.2 Control Registers Several control registers are used in conjunction with the TBLRD and TBLWT instructions. These include the: • EECON1 register • EECON2 register • TABLAT register • TBLPTR registers 5.2.1 EECON1 AND EECON2 REGISTERS EECON1 is the control register for memory accesses. EECON2 is not a physical register. Reading EECON2 will read all '0's. The EECON2 register is used exclusively in the memory write and erase sequences. Control bit EEPGD determines if the access will be a program or data EEPROM memory access. When clear, any subsequent operations will operate on the data EEPROM memory. When set, any subsequent operations will operate on the program memory. Control bit CFGS determines if the access will be to the configuration registers or to program memory/data EEPROM memory. When set, subsequent operations will operate on configuration registers, regardless of EEPGD (see “Special Features of the CPU”, Section 19.0). When clear, memory selection access is determined by EEPGD. The FREE bit, when set, will allow a program memory erase operation. When the FREE bit is set, the erase operation is initiated on the next WR command. When FREE is clear, only writes are enabled. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set when a write operation is interrupted by a MCLR Reset or a WDT Time-out Reset during normal operation. In these situations, the user can check the WRERR bit and rewrite the location. It is necessary to reload the data and address registers (EEDATA and EEADR), due to RESET values of zero. Control bit WR initiates write operations. This bit cannot be cleared, only set, in software. It is cleared in hardware at the completion of the write operation. The inability to clear the WR bit in software prevents the accidental or premature termination of a write operation. Table Pointer(1) Table Latch (8-bit) TBLPTRH TBLPTRL TABLAT Program Memory (TBLPTR) TBLPTRU Instruction: TBLWT* Note 1: Table Pointer actually points to one of eight holding registers, the address of which is determined by TBLPTRL<2:0>. The process for physically writing data to the Program Memory Array is discussed in Section 5.5. Holding Registers Program Memory Note: Interrupt flag bit EEIF, in the PIR2 register, is set when the write is complete. It must be cleared in software.© 2006 Microchip Technology Inc. DS39564C-page 57 PIC18FXX2 REGISTER 5-1: EECON1 REGISTER (ADDRESS FA6h) R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD CFGS — FREE WRERR WREN WR RD bit 7 bit 0 bit 7 EEPGD: FLASH Program or Data EEPROM Memory Select bit 1 = Access FLASH Program memory 0 = Access Data EEPROM memory bit 6 CFGS: FLASH Program/Data EE or Configuration Select bit 1 = Access Configuration registers 0 = Access FLASH Program or Data EEPROM memory bit 5 Unimplemented: Read as '0' bit 4 FREE: FLASH Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only bit 3 WRERR: FLASH Program/Data EE Error Flag bit 1 = A write operation is prematurely terminated (any RESET during self-timed programming in normal operation) 0 = The write operation completed Note: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition. bit 2 WREN: FLASH Program/Data EE Write Enable bit 1 = Allows write cycles 0 = Inhibits write to the EEPROM bit 1 WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle. (The operation is self timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete bit 0 RD: Read Control bit 1 = Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1.) 0 = Does not initiate an EEPROM read Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 58 © 2006 Microchip Technology Inc. 5.2.2 TABLAT - TABLE LATCH REGISTER The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The Table Latch is used to hold 8-bit data during data transfers between program memory and data RAM. 5.2.3 TBLPTR - TABLE POINTER REGISTER The Table Pointer (TBLPTR) addresses a byte within the program memory. The TBLPTR is comprised of three SFR registers: Table Pointer Upper Byte, Table Pointer High Byte and Table Pointer Low Byte (TBLPTRU:TBLPTRH:TBLPTRL). These three registers join to form a 22-bit wide pointer. The low order 21 bits allow the device to address up to 2 Mbytes of program memory space. The 22nd bit allows access to the Device ID, the User ID and the Configuration bits. The table pointer, TBLPTR, is used by the TBLRD and TBLWT instructions. These instructions can update the TBLPTR in one of four ways based on the table operation. These operations are shown in Table 5-1. These operations on the TBLPTR only affect the low order 21 bits. 5.2.4 TABLE POINTER BOUNDARIES TBLPTR is used in reads, writes, and erases of the FLASH program memory. When a TBLRD is executed, all 22 bits of the Table Pointer determine which byte is read from program memory into TABLAT. When a TBLWT is executed, the three LSbs of the Table Pointer (TBLPTR<2:0>) determine which of the eight program memory holding registers is written to. When the timed write to program memory (long write) begins, the 19 MSbs of the Table Pointer, TBLPTR (TBLPTR<21:3>), will determine which program memory block of 8 bytes is written to. For more detail, see Section 5.5 (“Writing to FLASH Program Memory”). When an erase of program memory is executed, the 16 MSbs of the Table Pointer (TBLPTR<21:6>) point to the 64-byte block that will be erased. The Least Significant bits (TBLPTR<5:0>) are ignored. Figure 5-3 describes the relevant boundaries of TBLPTR based on FLASH program memory operations. TABLE 5-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS FIGURE 5-3: TABLE POINTER BOUNDARIES BASED ON OPERATION Example Operation on Table Pointer TBLRD* TBLWT* TBLPTR is not modified TBLRD*+ TBLWT*+ TBLPTR is incremented after the read/write TBLRD*- TBLWT*- TBLPTR is decremented after the read/write TBLRD+* TBLWT+* TBLPTR is incremented before the read/write 21 16 15 8 7 0 ERASE - TBLPTR<21:6> WRITE - TBLPTR<21:3> READ - TBLPTR<21:0> TBLPTRU TBLPTRH TBLPTRL© 2006 Microchip Technology Inc. DS39564C-page 59 PIC18FXX2 5.3 Reading the FLASH Program Memory The TBLRD instruction is used to retrieve data from program memory and place into data RAM. Table Reads from program memory are performed one byte at a time. TBLPTR points to a byte address in program space. Executing TBLRD places the byte pointed to into TABLAT. In addition, TBLPTR can be modified automatically for the next Table Read operation. The internal program memory is typically organized by words. The Least Significant bit of the address selects between the high and low bytes of the word. Figure 5-4 shows the interface between the internal program memory and the TABLAT. FIGURE 5-4: READS FROM FLASH PROGRAM MEMORY EXAMPLE 5-1: READING A FLASH PROGRAM MEMORY WORD (Even Byte Address) Program Memory (Odd Byte Address) TBLRD TABLAT TBLPTR = xxxxx1 FETCH Instruction Register (IR) Read Register TBLPTR = xxxxx0 MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base MOVWF TBLPTRU ; address of the word MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL READ_WORD TBLRD*+ ; read into TABLAT and increment MOVF TABLAT, W ; get data MOVWF WORD_EVEN TBLRD*+ ; read into TABLAT and increment MOVF TABLAT, W ; get data MOVWF WORD_ODDPIC18FXX2 DS39564C-page 60 © 2006 Microchip Technology Inc. 5.4 Erasing FLASH Program memory The minimum erase block is 32 words or 64 bytes. Only through the use of an external programmer, or through ICSP control can larger blocks of program memory be bulk erased. Word erase in the FLASH array is not supported. When initiating an erase sequence from the microcontroller itself, a block of 64 bytes of program memory is erased. The Most Significant 16 bits of the TBLPTR<21:6> point to the block being erased. TBLPTR<5:0> are ignored. The EECON1 register commands the erase operation. The EEPGD bit must be set to point to the FLASH program memory. The WREN bit must be set to enable write operations. The FREE bit is set to select an erase operation. For protection, the write initiate sequence for EECON2 must be used. A long write is necessary for erasing the internal FLASH. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. 5.4.1 FLASH PROGRAM MEMORY ERASE SEQUENCE The sequence of events for erasing a block of internal program memory location is: 1. Load table pointer with address of row being erased. 2. Set EEPGD bit to point to program memory, clear CFGS bit to access program memory, set WREN bit to enable writes, and set FREE bit to enable the erase. 3. Disable interrupts. 4. Write 55h to EECON2. 5. Write AAh to EECON2. 6. Set the WR bit. This will begin the row erase cycle. 7. The CPU will stall for duration of the erase (about 2 ms using internal timer). 8. Re-enable interrupts. EXAMPLE 5-2: ERASING A FLASH PROGRAM MEMORY ROW MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL ERASE_ROW BSF EECON1,EEPGD ; point to FLASH program memory BCF EECON1,CFGS ; access FLASH program memory BSF EECON1,WREN ; enable write to memory BSF EECON1,FREE ; enable Row Erase operation BCF INTCON,GIE ; disable interrupts MOVLW 55h Required MOVWF EECON2 ; write 55h Sequence MOVLW AAh MOVWF EECON2 ; write AAh BSF EECON1,WR ; start erase (CPU stall) BSF INTCON,GIE ; re-enable interrupts© 2006 Microchip Technology Inc. DS39564C-page 61 PIC18FXX2 5.5 Writing to FLASH Program Memory The minimum programming block is 4 words or 8 bytes. Word or byte programming is not supported. Table Writes are used internally to load the holding registers needed to program the FLASH memory. There are 8 holding registers used by the Table Writes for programming. Since the Table Latch (TABLAT) is only a single byte, the TBLWT instruction has to be executed 8 times for each programming operation. All of the Table Write operations will essentially be short writes, because only the holding registers are written. At the end of updating 8 registers, the EECON1 register must be written to, to start the programming operation with a long write. The long write is necessary for programming the internal FLASH. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. The EEPROM on-chip timer controls the write time. The write/erase voltages are generated by an on-chip charge pump rated to operate over the voltage range of the device for byte or word operations. FIGURE 5-5: TABLE WRITES TO FLASH PROGRAM MEMORY 5.5.1 FLASH PROGRAM MEMORY WRITE SEQUENCE The sequence of events for programming an internal program memory location should be: 1. Read 64 bytes into RAM. 2. Update data values in RAM as necessary. 3. Load Table Pointer with address being erased. 4. Do the row erase procedure. 5. Load Table Pointer with address of first byte being written. 6. Write the first 8 bytes into the holding registers with auto-increment (TBLWT*+ or TBLWT+*). 7. Set EEPGD bit to point to program memory, clear the CFGS bit to access program memory, and set WREN to enable byte writes. 8. Disable interrupts. 9. Write 55h to EECON2. 10. Write AAh to EECON2. 11. Set the WR bit. This will begin the write cycle. 12. The CPU will stall for duration of the write (about 2 ms using internal timer). 13. Re-enable interrupts. 14. Repeat steps 6-14 seven times, to write 64 bytes. 15. Verify the memory (Table Read). This procedure will require about 18 ms to update one row of 64 bytes of memory. An example of the required code is given in Example 5-3. Holding Register TABLAT Holding Register TBLPTR = xxxxx7 Holding Register TBLPTR = xxxxx1 Holding Register TBLPTR = xxxxx0 8 8 8 8 Write Register TBLPTR = xxxxx2 Program Memory Note: Before setting the WR bit, the table pointer address needs to be within the intended address range of the 8 bytes in the holding registers.PIC18FXX2 DS39564C-page 62 © 2006 Microchip Technology Inc. EXAMPLE 5-3: WRITING TO FLASH PROGRAM MEMORY MOVLW D'64 ; number of bytes in erase block MOVWF COUNTER MOVLW BUFFER_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL READ_BLOCK TBLRD*+ ; read into TABLAT, and inc MOVF TABLAT, W ; get data MOVWF POSTINC0 ; store data DECFSZ COUNTER ; done? BRA READ_BLOCK ; repeat MODIFY_WORD MOVLW DATA_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW DATA_ADDR_LOW MOVWF FSR0L MOVLW NEW_DATA_LOW ; update buffer word MOVWF POSTINC0 MOVLW NEW_DATA_HIGH MOVWF INDF0 ERASE_BLOCK MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base MOVWF TBLPTRU ; address of the memory block MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL BSF EECON1,EEPGD ; point to FLASH program memory BCF EECON1,CFGS ; access FLASH program memory BSF EECON1,WREN ; enable write to memory BSF EECON1,FREE ; enable Row Erase operation BCF INTCON,GIE ; disable interrupts MOVLW 55h MOVWF EECON2 ; write 55h MOVLW AAh MOVWF EECON2 ; write AAh BSF EECON1,WR ; start erase (CPU stall) BSF INTCON,GIE ; re-enable interrupts TBLRD*- ; dummy read decrement WRITE_BUFFER_BACK MOVLW 8 ; number of write buffer groups of 8 bytes MOVWF COUNTER_HI MOVLW BUFFER_ADDR_HIGH ; point to buffer MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L PROGRAM_LOOP MOVLW 8 ; number of bytes in holding register MOVWF COUNTER WRITE_WORD_TO_HREGS MOVF POSTINC0, W ; get low byte of buffer data MOVWF TABLAT ; present data to table latch TBLWT+* ; write data, perform a short write ; to internal TBLWT holding register. DECFSZ COUNTER ; loop until buffers are full BRA WRITE_WORD_TO_HREGS© 2006 Microchip Technology Inc. DS39564C-page 63 PIC18FXX2 EXAMPLE 5-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED) 5.5.2 WRITE VERIFY Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 5.5.3 UNEXPECTED TERMINATION OF WRITE OPERATION If a write is terminated by an unplanned event, such as loss of power or an unexpected RESET, the memory location just programmed should be verified and reprogrammed if needed.The WRERR bit is set when a write operation is interrupted by a MCLR Reset, or a WDT Time-out Reset during normal operation. In these situations, users can check the WRERR bit and rewrite the location. 5.5.4 PROTECTION AGAINST SPURIOUS WRITES To protect against spurious writes to FLASH program memory, the write initiate sequence must also be followed. See “Special Features of the CPU” (Section 19.0) for more detail. 5.6 FLASH Program Operation During Code Protection See “Special Features of the CPU” (Section 19.0) for details on code protection of FLASH program memory. TABLE 5-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY PROGRAM_MEMORY BSF EECON1,EEPGD ; point to FLASH program memory BCF EECON1,CFGS ; access FLASH program memory BSF EECON1,WREN ; enable write to memory BCF INTCON,GIE ; disable interrupts MOVLW 55h Required MOVWF EECON2 ; write 55h Sequence MOVLW AAh MOVWF EECON2 ; write AAh BSF EECON1,WR ; start program (CPU stall) BSF INTCON,GIE ; re-enable interrupts DECFSZ COUNTER_HI ; loop until done BRA PROGRAM_LOOP BCF EECON1,WREN ; disable write to memory Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on All Other RESETS FF8h TBLPTRU — — bit21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 --00 0000 FF7h TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 0000 0000 FF6h TBLPTRL Program Memory Table Pointer High Byte (TBLPTR<7:0>) 0000 0000 0000 0000 FF5h TABLAT Program Memory Table Latch 0000 0000 0000 0000 FF2h INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INTE RBIE TMR0IF INTF RBIF 0000 000x 0000 000u FA7h EECON2 EEPROM Control Register2 (not a physical register) — — FA6h EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 uu-0 u000 FA2h IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111 FA1h PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000 FA0h PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000 Legend: x = unknown, u = unchanged, r = reserved, - = unimplemented read as '0'. Shaded cells are not used during FLASH/EEPROM access.PIC18FXX2 DS39564C-page 64 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 65 PIC18FXX2 6.0 DATA EEPROM MEMORY The Data EEPROM is readable and writable during normal operation over the entire VDD range. The data memory is not directly mapped in the register file space. Instead, it is indirectly addressed through the Special Function Registers (SFR). There are four SFRs used to read and write the program and data EEPROM memory. These registers are: • EECON1 • EECON2 • EEDATA • EEADR The EEPROM data memory allows byte read and write. When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and EEADR holds the address of the EEPROM location being accessed. These devices have 256 bytes of data EEPROM with an address range from 0h to FFh. The EEPROM data memory is rated for high erase/ write cycles. A byte write automatically erases the location and writes the new data (erase-before-write). The write time is controlled by an on-chip timer. The write time will vary with voltage and temperature, as well as from chip to chip. Please refer to parameter D122 (Electrical Characteristics, Section 22.0) for exact limits. 6.1 EEADR The address register can address up to a maximum of 256 bytes of data EEPROM. 6.2 EECON1 and EECON2 Registers EECON1 is the control register for EEPROM memory accesses. EECON2 is not a physical register. Reading EECON2 will read all '0's. The EECON2 register is used exclusively in the EEPROM write sequence. Control bits RD and WR initiate read and write operations, respectively. These bits cannot be cleared, only set, in software. They are cleared in hardware at the completion of the read or write operation. The inability to clear the WR bit in software prevents the accidental or premature termination of a write operation. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set when a write operation is interrupted by a MCLR Reset, or a WDT Time-out Reset during normal operation. In these situations, the user can check the WRERR bit and rewrite the location. It is necessary to reload the data and address registers (EEDATA and EEADR), due to the RESET condition forcing the contents of the registers to zero. Note: Interrupt flag bit, EEIF in the PIR2 register, is set when write is complete. It must be cleared in software.PIC18FXX2 DS39564C-page 66 © 2006 Microchip Technology Inc. REGISTER 6-1: EECON1 REGISTER (ADDRESS FA6h) R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD CFGS — FREE WRERR WREN WR RD bit 7 bit 0 bit 7 EEPGD: FLASH Program or Data EEPROM Memory Select bit 1 = Access FLASH Program memory 0 = Access Data EEPROM memory bit 6 CFGS: FLASH Program/Data EE or Configuration Select bit 1 = Access Configuration or Calibration registers 0 = Access FLASH Program or Data EEPROM memory bit 5 Unimplemented: Read as '0' bit 4 FREE: FLASH Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only bit 3 WRERR: FLASH Program/Data EE Error Flag bit 1 = A write operation is prematurely terminated (any MCLR or any WDT Reset during self-timed programming in normal operation) 0 = The write operation completed Note: When a WRERR occurs, the EEPGD or FREE bits are not cleared. This allows tracing of the error condition. bit 2 WREN: FLASH Program/Data EE Write Enable bit 1 = Allows write cycles 0 = Inhibits write to the EEPROM bit 1 WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle. (The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete bit 0 RD: Read Control bit 1 = Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1.) 0 = Does not initiate an EEPROM read Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 67 PIC18FXX2 6.3 Reading the Data EEPROM Memory To read a data memory location, the user must write the address to the EEADR register, clear the EEPGD control bit (EECON1<7>), clear the CFGS control bit (EECON1<6>), and then set control bit RD (EECON1<0>). The data is available for the very next instruction cycle; therefore, the EEDATA register can be read by the next instruction. EEDATA will hold this value until another read operation, or until it is written to by the user (during a write operation). EXAMPLE 6-1: DATA EEPROM READ 6.4 Writing to the Data EEPROM Memory To write an EEPROM data location, the address must first be written to the EEADR register and the data written to the EEDATA register. Then the sequence in Example 6-2 must be followed to initiate the write cycle. The write will not initiate if the above sequence is not exactly followed (write 55h to EECON2, write AAh to EECON2, then set WR bit) for each byte. It is strongly recommended that interrupts be disabled during this code segment. Additionally, the WREN bit in EECON1 must be set to enable writes. This mechanism prevents accidental writes to data EEPROM due to unexpected code execution (i.e., runaway programs). The WREN bit should be kept clear at all times, except when updating the EEPROM. The WREN bit is not cleared by hardware. After a write sequence has been initiated, EECON1, EEADR and EDATA cannot be modified. The WR bit will be inhibited from being set unless the WREN bit is set. The WREN bit must be set on a previous instruction. Both WR and WREN cannot be set with the same instruction. At the completion of the write cycle, the WR bit is cleared in hardware and the EEPROM Write Complete Interrupt Flag bit (EEIF) is set. The user may either enable this interrupt, or poll this bit. EEIF must be cleared by software. EXAMPLE 6-2: DATA EEPROM WRITE MOVLW DATA_EE_ADDR ; MOVWF EEADR ; Data Memory Address to read BCF EECON1, EEPGD ; Point to DATA memory BCF EECON1, CFGS ; Access program FLASH or Data EEPROM memory BSF EECON1, RD ; EEPROM Read MOVF EEDATA, W ; W = EEDATA MOVLW DATA_EE_ADDR ; MOVWF EEADR ; Data Memory Address to read MOVLW DATA_EE_DATA ; MOVWF EEDATA ; Data Memory Value to write BCF EECON1, EEPGD ; Point to DATA memory BCF EECON1, CFGS ; Access program FLASH or Data EEPROM memory BSF EECON1, WREN ; Enable writes BCF INTCON, GIE ; Disable interrupts Required MOVLW 55h ; Sequence MOVWF EECON2 ; Write 55h MOVLW AAh ; MOVWF EECON2 ; Write AAh BSF EECON1, WR ; Set WR bit to begin write BSF INTCON, GIE ; Enable interrupts . ; user code execution . . BCF EECON1, WREN ; Disable writes on write complete (EEIF set)PIC18FXX2 DS39564C-page 68 © 2006 Microchip Technology Inc. 6.5 Write Verify Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 6.6 Protection Against Spurious Write There are conditions when the device may not want to write to the data EEPROM memory. To protect against spurious EEPROM writes, various mechanisms have been built-in. On power-up, the WREN bit is cleared. Also, the Power-up Timer (72 ms duration) prevents EEPROM write. The write initiate sequence and the WREN bit together help prevent an accidental write during brown-out, power glitch, or software malfunction. 6.7 Operation During Code Protect Data EEPROM memory has its own code protect mechanism. External Read and Write operations are disabled if either of these mechanisms are enabled. The microcontroller itself can both read and write to the internal Data EEPROM, regardless of the state of the code protect configuration bit. Refer to “Special Features of the CPU” (Section 19.0) for additional information. 6.8 Using the Data EEPROM The data EEPROM is a high endurance, byte addressable array that has been optimized for the storage of frequently changing information (e.g., program variables or other data that are updated often). Frequently changing values will typically be updated more often than specification D124. If this is not the case, an array refresh must be performed. For this reason, variables that change infrequently (such as constants, IDs, calibration, etc.) should be stored in FLASH program memory. A simple data EEPROM refresh routine is shown in Example 6-3. EXAMPLE 6-3: DATA EEPROM REFRESH ROUTINE Note: If data EEPROM is only used to store constants and/or data that changes rarely, an array refresh is likely not required. See specification D124. clrf EEADR ; Start at address 0 bcf EECON1,CFGS ; Set for memory bcf EECON1,EEPGD ; Set for Data EEPROM bcf INTCON,GIE ; Disable interrupts bsf EECON1,WREN ; Enable writes Loop ; Loop to refresh array bsf EECON1,RD ; Read current address movlw 55h ; movwf EECON2 ; Write 55h movlw AAh ; movwf EECON2 ; Write AAh bsf EECON1,WR ; Set WR bit to begin write btfsc EECON1,WR ; Wait for write to complete bra $-2 incfsz EEADR,F ; Increment address bra Loop ; Not zero, do it again bcf EECON1,WREN ; Disable writes bsf INTCON,GIE ; Enable interrupts© 2006 Microchip Technology Inc. DS39564C-page 69 PIC18FXX2 TABLE 6-1: REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on All Other RESETS FF2h INTCON GIE/ GIEH PEIE/ GIEL T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u FA9h EEADR EEPROM Address Register 0000 0000 0000 0000 FA8h EEDATA EEPROM Data Register 0000 0000 0000 0000 FA7h EECON2 EEPROM Control Register2 (not a physical register) — — FA6h EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 uu-0 u000 FA2h IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111 FA1h PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000 FA0h PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000 Legend: x = unknown, u = unchanged, r = reserved, - = unimplemented, read as '0'. Shaded cells are not used during FLASH/EEPROM access.PIC18FXX2 DS39564C-page 70 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 71 PIC18FXX2 7.0 8 X 8 HARDWARE MULTIPLIER 7.1 Introduction An 8 x 8 hardware multiplier is included in the ALU of the PIC18FXX2 devices. By making the multiply a hardware operation, it completes in a single instruction cycle. This is an unsigned multiply that gives a 16-bit result. The result is stored into the 16-bit product register pair (PRODH:PRODL). The multiplier does not affect any flags in the ALUSTA register. Making the 8 x 8 multiplier execute in a single cycle gives the following advantages: • Higher computational throughput • Reduces code size requirements for multiply algorithms The performance increase allows the device to be used in applications previously reserved for Digital Signal Processors. Table 7-1 shows a performance comparison between enhanced devices using the single cycle hardware multiply, and performing the same function without the hardware multiply. TABLE 7-1: PERFORMANCE COMPARISON 7.2 Operation Example 7-1 shows the sequence to do an 8 x 8 unsigned multiply. Only one instruction is required when one argument of the multiply is already loaded in the WREG register. Example 7-2 shows the sequence to do an 8 x 8 signed multiply. To account for the sign bits of the arguments, each argument’s Most Significant bit (MSb) is tested and the appropriate subtractions are done. EXAMPLE 7-1: 8 x 8 UNSIGNED MULTIPLY ROUTINE EXAMPLE 7-2: 8 x 8 SIGNED MULTIPLY ROUTINE Example 7-3 shows the sequence to do a 16 x 16 unsigned multiply. Equation 7-1 shows the algorithm that is used. The 32-bit result is stored in four registers, RES3:RES0. EQUATION 7-1: 16 x 16 UNSIGNED MULTIPLICATION ALGORITHM Routine Multiply Method Program Memory (Words) Cycles (Max) Time @ 40 MHz @ 10 MHz @ 4 MHz 8 x 8 unsigned Without hardware multiply 13 69 6.9 μs 27.6 μs 69 μs Hardware multiply 1 1 100 ns 400 ns 1 μs 8 x 8 signed Without hardware multiply 33 91 9.1 μs 36.4 μs 91 μs Hardware multiply 6 6 600 ns 2.4 μs 6 μs 16 x 16 unsigned Without hardware multiply 21 242 24.2 μs 96.8 μs 242 μs Hardware multiply 24 24 2.4 μs 9.6 μs 24 μs 16 x 16 signed Without hardware multiply 52 254 25.4 μs 102.6 μs 254 μs Hardware multiply 36 36 3.6 μs 14.4 μs 36 μs MOVF ARG1, W ; MULWF ARG2 ; ARG1 * ARG2 -> ; PRODH:PRODL MOVF ARG1, W MULWF ARG2 ; ARG1 * ARG2 -> ; PRODH:PRODL BTFSC ARG2, SB ; Test Sign Bit SUBWF PRODH, F ; PRODH = PRODH ; - ARG1 MOVF ARG2, W BTFSC ARG1, SB ; Test Sign Bit SUBWF PRODH, F ; PRODH = PRODH ; - ARG2 RES3:RES0 = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28 ) + (ARG1L • ARG2H • 28) + (ARG1L • ARG2L)PIC18FXX2 DS39564C-page 72 © 2006 Microchip Technology Inc. EXAMPLE 7-3: 16 x 16 UNSIGNED MULTIPLY ROUTINE Example 7-4 shows the sequence to do a 16 x 16 signed multiply. Equation 7-2 shows the algorithm used. The 32-bit result is stored in four registers, RES3:RES0. To account for the sign bits of the arguments, each argument pairs Most Significant bit (MSb) is tested and the appropriate subtractions are done. EQUATION 7-2: 16 x 16 SIGNED MULTIPLICATION ALGORITHM EXAMPLE 7-4: 16 x 16 SIGNED MULTIPLY ROUTINE MOVF ARG1L, W MULWF ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL MOVFF PRODH, RES1 ; MOVFF PRODL, RES0 ; ; MOVF ARG1H, W MULWF ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL MOVFF PRODH, RES3 ; MOVFF PRODL, RES2 ; ; MOVF ARG1L, W MULWF ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; MOVF ARG1H, W ; MULWF ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; RES3:RES0 = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28) + (ARG1L • ARG2H • 28) + (ARG1L • ARG2L) + (-1 • ARG2H<7> • ARG1H:ARG1L • 216) + (-1 • ARG1H<7> • ARG2H:ARG2L • 216) MOVF ARG1L, W MULWF ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL MOVFF PRODH, RES1 ; MOVFF PRODL, RES0 ; ; MOVF ARG1H, W MULWF ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL MOVFF PRODH, RES3 ; MOVFF PRODL, RES2 ; ; MOVF ARG1L, W MULWF ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; MOVF ARG1H, W ; MULWF ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL MOVF PRODL, W ; ADDWF RES1, F ; Add cross MOVF PRODH, W ; products ADDWFC RES2, F ; CLRF WREG ; ADDWFC RES3, F ; ; BTFSS ARG2H, 7 ; ARG2H:ARG2L neg? BRA SIGN_ARG1 ; no, check ARG1 MOVF ARG1L, W ; SUBWF RES2 ; MOVF ARG1H, W ; SUBWFB RES3 ; SIGN_ARG1 BTFSS ARG1H, 7 ; ARG1H:ARG1L neg? BRA CONT_CODE ; no, done MOVF ARG2L, W ; SUBWF RES2 ; MOVF ARG2H, W ; SUBWFB RES3 ; CONT_CODE : © 2006 Microchip Technology Inc. DS39564C-page 73 PIC18FXX2 8.0 INTERRUPTS The PIC18FXX2 devices have multiple interrupt sources and an interrupt priority feature that allows each interrupt source to be assigned a high priority level or a low priority level. The high priority interrupt vector is at 000008h and the low priority interrupt vector is at 000018h. High priority interrupt events will override any low priority interrupts that may be in progress. There are ten registers which are used to control interrupt operation. These registers are: • RCON • INTCON • INTCON2 • INTCON3 • PIR1, PIR2 • PIE1, PIE2 • IPR1, IPR2 It is recommended that the Microchip header files supplied with MPLAB® IDE be used for the symbolic bit names in these registers. This allows the assembler/ compiler to automatically take care of the placement of these bits within the specified register. Each interrupt source, except INT0, has three bits to control its operation. The functions of these bits are: • Flag bit to indicate that an interrupt event occurred • Enable bit that allows program execution to branch to the interrupt vector address when the flag bit is set • Priority bit to select high priority or low priority The interrupt priority feature is enabled by setting the IPEN bit (RCON<7>). When interrupt priority is enabled, there are two bits which enable interrupts globally. Setting the GIEH bit (INTCON<7>) enables all interrupts that have the priority bit set. Setting the GIEL bit (INTCON<6>) enables all interrupts that have the priority bit cleared. When the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address 000008h or 000018h, depending on the priority level. Individual interrupts can be disabled through their corresponding enable bits. When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PICmicro® mid-range devices. In Compatibility mode, the interrupt priority bits for each source have no effect. INTCON<6> is the PEIE bit, which enables/disables all peripheral interrupt sources. INTCON<7> is the GIE bit, which enables/disables all interrupt sources. All interrupts branch to address 000008h in Compatibility mode. When an interrupt is responded to, the Global Interrupt Enable bit is cleared to disable further interrupts. If the IPEN bit is cleared, this is the GIE bit. If interrupt priority levels are used, this will be either the GIEH or GIEL bit. High priority interrupt sources can interrupt a low priority interrupt. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (000008h or 000018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bits must be cleared in software before re-enabling interrupts to avoid recursive interrupts. The “return from interrupt” instruction, RETFIE, exits the interrupt routine and sets the GIE bit (GIEH or GIEL if priority levels are used), which re-enables interrupts. For external interrupt events, such as the INT pins or the PORTB input change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding enable bit or the GIE bit. Note: Do not use the MOVFF instruction to modify any of the Interrupt control registers while any interrupt is enabled. Doing so may cause erratic microcontroller behavior.PIC18FXX2 DS39564C-page 74 © 2006 Microchip Technology Inc. FIGURE 8-1: INTERRUPT LOGIC TMR0IE GIEH/GIE GIEL/PEIE Wake-up if in SLEEP mode Interrupt to CPU Vector to location 0008h INT2IF INT2IE INT2IP INT1IF INT1IE INT1IP TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP IPEN TMR0IF TMR0IP INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP RBIF RBIE RBIP INT0IF INT0IE GIEL/PEIE Interrupt to CPU Vector to Location IPEN IPE 0018h Peripheral Interrupt Flag bit Peripheral Interrupt Enable bit Peripheral Interrupt Priority bit Peripheral Interrupt Flag bit Peripheral Interrupt Enable bit Peripheral Interrupt Priority bit TMR1IF TMR1IE TMR1IP XXXXIF XXXXIE XXXXIP Additional Peripheral Interrupts TMR1IF TMR1IE TMR1IP High Priority Interrupt Generation Low Priority Interrupt Generation XXXXIF XXXXIE XXXXIP Additional Peripheral Interrupts GIE/GIEH© 2006 Microchip Technology Inc. DS39564C-page 75 PIC18FXX2 8.1 INTCON Registers The INTCON Registers are readable and writable registers, which contain various enable, priority and flag bits. REGISTER 8-1: INTCON REGISTER Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF bit 7 bit 0 bit 7 GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts When IPEN = 1: 1 = Enables all high priority interrupts 0 = Disables all interrupts bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts When IPEN = 1: 1 = Enables all low priority peripheral interrupts 0 = Disables all low priority peripheral interrupts bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 overflow interrupt 0 = Disables the TMR0 overflow interrupt bit 4 INT0IE: INT0 External Interrupt Enable bit 1 = Enables the INT0 external interrupt 0 = Disables the INT0 external interrupt bit 3 RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow bit 1 INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared in software) 0 = The INT0 external interrupt did not occur bit 0 RBIF: RB Port Change Interrupt Flag bit 1 = At least one of the RB7:RB4 pins changed state (must be cleared in software) 0 = None of the RB7:RB4 pins have changed state Note: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 76 © 2006 Microchip Technology Inc. REGISTER 8-2: INTCON2 REGISTER R/W-1 R/W-1 R/W-1 R/W-1 U-0 R/W-1 U-0 R/W-1 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP bit 7 bit 0 bit 7 RBPU: PORTB Pull-up Enable bit 1 = All PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values bit 6 INTEDG0:External Interrupt0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 5 INTEDG1: External Interrupt1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 4 INTEDG2: External Interrupt2 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 3 Unimplemented: Read as '0' bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 Unimplemented: Read as '0' bit 0 RBIP: RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.© 2006 Microchip Technology Inc. DS39564C-page 77 PIC18FXX2 REGISTER 8-3: INTCON3 REGISTER R/W-1 R/W-1 U-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF bit 7 bit 0 bit 7 INT2IP: INT2 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 INT1IP: INT1 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 Unimplemented: Read as '0' bit 4 INT2IE: INT2 External Interrupt Enable bit 1 = Enables the INT2 external interrupt 0 = Disables the INT2 external interrupt bit 3 INT1IE: INT1 External Interrupt Enable bit 1 = Enables the INT1 external interrupt 0 = Disables the INT1 external interrupt bit 2 Unimplemented: Read as '0' bit 1 INT2IF: INT2 External Interrupt Flag bit 1 = The INT2 external interrupt occurred (must be cleared in software) 0 = The INT2 external interrupt did not occur bit 0 INT1IF: INT1 External Interrupt Flag bit 1 = The INT1 external interrupt occurred (must be cleared in software) 0 = The INT1 external interrupt did not occur Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.PIC18FXX2 DS39564C-page 78 © 2006 Microchip Technology Inc. 8.2 PIR Registers The PIR registers contain the individual flag bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Flag Registers (PIR1, PIR2). REGISTER 8-4: PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1 Note 1: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt, and after servicing that interrupt. R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF bit 7 bit 0 bit 7 PSPIF(1): Parallel Slave Port Read/Write Interrupt Flag bit 1 = A read or a write operation has taken place (must be cleared in software) 0 = No read or write has occurred bit 6 ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete bit 5 RCIF: USART Receive Interrupt Flag bit 1 = The USART receive buffer, RCREG, is full (cleared when RCREG is read) 0 = The USART receive buffer is empty bit 4 TXIF: USART Transmit Interrupt Flag bit (see Section 16.0 for details on TXIF functionality) 1 = The USART transmit buffer, TXREG, is empty (cleared when TXREG is written) 0 = The USART transmit buffer is full bit 3 SSPIF: Master Synchronous Serial Port Interrupt Flag bit 1 = The transmission/reception is complete (must be cleared in software) 0 = Waiting to transmit/receive bit 2 CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = MR1 register did not overflow Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 79 PIC18FXX2 REGISTER 8-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF bit 7 bit 0 bit 7-5 Unimplemented: Read as '0' bit 4 EEIF: Data EEPROM/FLASH Write Operation Interrupt Flag bit 1 = The Write operation is complete (must be cleared in software) 0 = The Write operation is not complete, or has not been started bit 3 BCLIF: Bus Collision Interrupt Flag bit 1 = A bus collision occurred (must be cleared in software) 0 = No bus collision occurred bit 2 LVDIF: Low Voltage Detect Interrupt Flag bit 1 = A low voltage condition occurred (must be cleared in software) 0 = The device voltage is above the Low Voltage Detect trip point bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared in software) 0 = TMR3 register did not overflow bit 0 CCP2IF: CCPx Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 80 © 2006 Microchip Technology Inc. 8.3 PIE Registers The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Enable Registers (PIE1, PIE2). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts. REGISTER 8-6: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE bit 7 bit 0 bit 7 PSPIE(1): Parallel Slave Port Read/Write Interrupt Enable bit 1 = Enables the PSP read/write interrupt 0 = Disables the PSP read/write interrupt bit 6 ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt bit 5 RCIE: USART Receive Interrupt Enable bit 1 = Enables the USART receive interrupt 0 = Disables the USART receive interrupt bit 4 TXIE: USART Transmit Interrupt Enable bit 1 = Enables the USART transmit interrupt 0 = Disables the USART transmit interrupt bit 3 SSPIE: Master Synchronous Serial Port Interrupt Enable bit 1 = Enables the MSSP interrupt 0 = Disables the MSSP interrupt bit 2 CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 81 PIC18FXX2 REGISTER 8-7: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE bit 7 bit 0 bit 7-5 Unimplemented: Read as '0' bit 4 EEIE: Data EEPROM/FLASH Write Operation Interrupt Enable bit 1 = Enabled 0 = Disabled bit 3 BCLIE: Bus Collision Interrupt Enable bit 1 = Enabled 0 = Disabled bit 2 LVDIE: Low Voltage Detect Interrupt Enable bit 1 = Enabled 0 = Disabled bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enables the TMR3 overflow interrupt 0 = Disables the TMR3 overflow interrupt bit 0 CCP2IE: CCP2 Interrupt Enable bit 1 = Enables the CCP2 interrupt 0 = Disables the CCP2 interrupt Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 82 © 2006 Microchip Technology Inc. 8.4 IPR Registers The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Priority Registers (IPR1, IPR2). The operation of the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set. REGISTER 8-8: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP bit 7 bit 0 bit 7 PSPIP(1): Parallel Slave Port Read/Write Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 RCIP: USART Receive Interrupt Priority bit 1 = High priority 0 = Low priority bit 4 TXIP: USART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 SSPIP: Master Synchronous Serial Port Interrupt Priority bit 1 = High priority 0 = Low priority bit 2 CCP1IP: CCP1 Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit set. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 83 PIC18FXX2 REGISTER 8-9: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2 U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP bit 7 bit 0 bit 7-5 Unimplemented: Read as '0' bit 4 EEIP: Data EEPROM/FLASH Write Operation Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 BCLIP: Bus Collision Interrupt Priority bit 1 = High priority 0 = Low priority bit 2 LVDIP: Low Voltage Detect Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 CCP2IP: CCP2 Interrupt Priority bit 1 = High priority 0 = Low priority Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 84 © 2006 Microchip Technology Inc. 8.5 RCON Register The RCON register contains the bit which is used to enable prioritized interrupts (IPEN). REGISTER 8-10: RCON REGISTER R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN — — RI TO PD POR BOR bit 7 bit 0 bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (16CXXX Compatibility mode) bit 6-5 Unimplemented: Read as '0' bit 4 RI: RESET Instruction Flag bit For details of bit operation, see Register 4-3 bit 3 TO: Watchdog Time-out Flag bit For details of bit operation, see Register 4-3 bit 2 PD: Power-down Detection Flag bit For details of bit operation, see Register 4-3 bit 1 POR: Power-on Reset Status bit For details of bit operation, see Register 4-3 bit 0 BOR: Brown-out Reset Status bit For details of bit operation, see Register 4-3 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 85 PIC18FXX2 8.6 INT0 Interrupt External interrupts on the RB0/INT0, RB1/INT1 and RB2/INT2 pins are edge triggered: either rising, if the corresponding INTEDGx bit is set in the INTCON2 register, or falling, if the INTEDGx bit is clear. When a valid edge appears on the RBx/INTx pin, the corresponding flag bit INTxF is set. This interrupt can be disabled by clearing the corresponding enable bit INTxE. Flag bit INTxF must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1 and INT2) can wake-up the processor from SLEEP, if bit INTxE was set prior to going into SLEEP. If the global interrupt enable bit GIE is set, the processor will branch to the interrupt vector following wake-up. Interrupt priority for INT1 and INT2 is determined by the value contained in the interrupt priority bits, INT1IP (INTCON3<6>) and INT2IP (INTCON3<7>). There is no priority bit associated with INT0. It is always a high priority interrupt source. 8.7 TMR0 Interrupt In 8-bit mode (which is the default), an overflow (FFh → 00h) in the TMR0 register will set flag bit TMR0IF. In 16-bit mode, an overflow (FFFFh → 0000h) in the TMR0H:TMR0L registers will set flag bit TMR0IF. The interrupt can be enabled/disabled by setting/ clearing enable bit T0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit TMR0IP (INTCON2<2>). See Section 10.0 for further details on the Timer0 module. 8.8 PORTB Interrupt-on-Change An input change on PORTB<7:4> sets flag bit RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit, RBIE (INTCON<3>). Interrupt priority for PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RBIP (INTCON2<0>). 8.9 Context Saving During Interrupts During an interrupt, the return PC value is saved on the stack. Additionally, the WREG, STATUS and BSR registers are saved on the fast return stack. If a fast return from interrupt is not used (See Section 4.3), the user may need to save the WREG, STATUS and BSR registers in software. Depending on the user’s application, other registers may also need to be saved. Equation 8-1 saves and restores the WREG, STATUS and BSR registers during an Interrupt Service Routine. EXAMPLE 8-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM MOVWF W_TEMP ; W_TEMP is in virtual bank MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere MOVFF BSR, BSR_TEMP ; BSR located anywhere ; ; USER ISR CODE ; MOVFF BSR_TEMP, BSR ; Restore BSR MOVF W_TEMP, W ; Restore WREG MOVFF STATUS_TEMP,STATUS ; Restore STATUSPIC18FXX2 DS39564C-page 86 © 2006 Microchip Technology Inc. NOTES: © 2006 Microchip Technology Inc. DS39564C-page 87 PIC18FXX2 9.0 I/O PORTS Depending on the device selected, there are either five ports or three ports available. Some pins of the I/O ports are multiplexed with an alternate function from the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Each port has three registers for its operation. These registers are: • TRIS register (data direction register) • PORT register (reads the levels on the pins of the device) • LAT register (output latch) The data latch (LAT register) is useful for read-modifywrite operations on the value that the I/O pins are driving. 9.1 PORTA, TRISA and LATA Registers PORTA is a 7-bit wide, bi-directional port. The corresponding Data Direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). Reading the PORTA register reads the status of the pins, whereas writing to it will write to the port latch. The Data Latch register (LATA) is also memory mapped. Read-modify-write operations on the LATA register reads and writes the latched output value for PORTA. The RA4 pin is multiplexed with the Timer0 module clock input to become the RA4/T0CKI pin. The RA4/ T0CKI pin is a Schmitt Trigger input and an open drain output. All other RA port pins have TTL input levels and full CMOS output drivers. The other PORTA pins are multiplexed with analog inputs and the analog VREF+ and VREF- inputs. The operation of each pin is selected by clearing/setting the control bits in the ADCON1 register (A/D Control Register1). The TRISA register controls the direction of the RA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs. EXAMPLE 9-1: INITIALIZING PORTA FIGURE 9-1: BLOCK DIAGRAM OF RA3:RA0 AND RA5 PINS Note: On a Power-on Reset, RA5 and RA3:RA0 are configured as analog inputs and read as ‘0’. RA6 and RA4 are configured as digital inputs. CLRF PORTA ; Initialize PORTA by ; clearing output ; data latches CLRF LATA ; Alternate method ; to clear output ; data latches MOVLW 0x07 ; Configure A/D MOVWF ADCON1 ; for digital inputs MOVLW 0xCF ; Value used to ; initialize data ; direction MOVWF TRISA ; Set RA<3:0> as inputs ; RA<5:4> as outputs Data Bus D Q CK Q D Q CK Q Q D EN P N WR LATA WR TRISA Data Latch TRIS Latch RD TRISA RD PORTA VSS VDD I/O pin(1) Note 1: I/O pins have protection diodes to VDD and VSS. Analog Input Mode TTL Input Buffer To A/D Converter and LVD Modules RD LATA or PORTA SS Input (RA5 only)PIC18FXX2 DS39564C-page 88 © 2006 Microchip Technology Inc. FIGURE 9-2: BLOCK DIAGRAM OF RA4/T0CKI PIN FIGURE 9-3: BLOCK DIAGRAM OF RA6 PIN Data Bus WR TRISA RD PORTA Data Latch TRIS Latch RD TRISA Schmitt Trigger Input Buffer N VSS I/O pin(1) TMR0 Clock Input D Q CK Q D Q CK Q EN Q D EN RD LATA WR LATA or PORTA Note 1: I/O pin has protection diode to VSS only. Data Bus D Q CK Q Q D EN P N WR LATA WR Data Latch TRIS Latch RD TRISA RD PORTA VSS VDD I/O pin(1) Note 1: I/O pins have protection diodes to VDD and VSS. or PORTA RD LATA ECRA6 or ECRA6 or Enable TTL Input Buffer RCRA6 RCRA6 Enable TRISA D Q CK Q© 2006 Microchip Technology Inc. DS39564C-page 89 PIC18FXX2 TABLE 9-1: PORTA FUNCTIONS TABLE 9-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA Name Bit# Buffer Function RA0/AN0 bit0 TTL Input/output or analog input. RA1/AN1 bit1 TTL Input/output or analog input. RA2/AN2/VREF- bit2 TTL Input/output or analog input or VREF-. RA3/AN3/VREF+ bit3 TTL Input/output or analog input or VREF+. RA4/T0CKI bit4 ST Input/output or external clock input for Timer0. Output is open drain type. RA5/SS/AN4/LVDIN bit5 TTL Input/output or slave select input for synchronous serial port or analog input, or low voltage detect input. OSC2/CLKO/RA6 bit6 TTL OSC2 or clock output or I/O pin. Legend: TTL = TTL input, ST = Schmitt Trigger input Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS PORTA — RA6 RA5 RA4 RA3 RA2 RA1 RA0 -x0x 0000 -u0u 0000 LATA — LATA Data Output Register -xxx xxxx -uuu uuuu TRISA — PORTA Data Direction Register -111 1111 -111 1111 ADCON1 ADFM ADCS2 — — PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 00-- 0000 Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA.PIC18FXX2 DS39564C-page 90 © 2006 Microchip Technology Inc. 9.2 PORTB, TRISB and LATB Registers PORTB is an 8-bit wide, bi-directional port. The corresponding Data Direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATB) is also memory mapped. Read-modify-write operations on the LATB register reads and writes the latched output value for PORTB. EXAMPLE 9-2: INITIALIZING PORTB Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit RBPU (INTCON2<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. Four of the PORTB pins, RB7:RB4, have an interrupton-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB4 pin configured as an output is excluded from the interrupton-change comparison). The input pins (of RB7:RB4) are compared with the old value latched on the last read of PORTB. The “mismatch” outputs of RB7:RB4 are OR’ed together to generate the RB Port Change Interrupt with flag bit, RBIF (INTCON<0>). This interrupt can wake the device from SLEEP. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) Any read or write of PORTB (except with the MOVFF instruction). This will end the mismatch condition. b) Clear flag bit RBIF. A mismatch condition will continue to set flag bit RBIF. Reading PORTB will end the mismatch condition and allow flag bit RBIF to be cleared. The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. RB3 can be configured by the configuration bit CCP2MX as the alternate peripheral pin for the CCP2 module (CCP2MX=’0’). FIGURE 9-4: BLOCK DIAGRAM OF RB7:RB4 PINS Note: On a Power-on Reset, these pins are configured as digital inputs. CLRF PORTB ; Initialize PORTB by ; clearing output ; data latches CLRF LATB ; Alternate method ; to clear output ; data latches MOVLW 0xCF ; Value used to ; initialize data ; direction MOVWF TRISB ; Set RB<3:0> as inputs ; RB<5:4> as outputs ; RB<7:6> as inputs Note 1: While in Low Voltage ICSP mode, the RB5 pin can no longer be used as a general purpose I/O pin, and should be held low during normal operation to protect against inadvertent ICSP mode entry. 2: When using Low Voltage ICSP programming (LVP), the pull-up on RB5 becomes disabled. If TRISB bit 5 is cleared, thereby setting RB5 as an output, LATB bit 5 must also be cleared for proper operation. Data Latch From other RBPU(2) P VDD I/O pin(1) D Q CK D Q CK Q D EN Q D EN Data Bus WR LATB WR TRISB Set RBIF TRIS Latch RD TRISB RD PORTB RB7:RB4 pins Weak Pull-up RD PORTB Latch TTL Input Buffer ST Buffer RB7:RB5 in Serial Programming mode Q3 Q1 RD LATB or PORTB Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>).© 2006 Microchip Technology Inc. DS39564C-page 91 PIC18FXX2 FIGURE 9-5: BLOCK DIAGRAM OF RB2:RB0 PINS FIGURE 9-6: BLOCK DIAGRAM OF RB3 PIN Data Latch RBPU(2) P VDD D Q CK D Q CK Q D EN Data Bus WR Port WR TRIS RD TRIS RD Port Weak Pull-up RD Port RB0/INT I/O pin(1) TTL Input Buffer Schmitt Trigger Buffer TRIS Latch Note 1: I/O pins have diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>). Data Latch P VDD D Q CK Q D EN Data Bus WR LATB or WR TRISB RD TRISB RD PORTB Weak Pull-up CCP2 Input(3) TTL Input Buffer Schmitt Trigger Buffer TRIS Latch RD LATB WR PORTB RBPU(2) CK D Enable(3) CCP Output RD PORTB CCP Output(3) 1 0 P N VDD VSS I/O pin(1) Q CCP2MX CCP2MX = 0 Note 1: I/O pin has diode protection to VDD and VSS. 2: To enable weak pull-ups, set the appropriate DDR bit(s) and clear the RBPU bit (INTCON2<7>). 3: The CCP2 input/output is multiplexed with RB3 if the CCP2MX bit is enabled (=’0’) in the configuration register. PIC18FXX2 DS39564C-page 92 © 2006 Microchip Technology Inc. TABLE 9-3: PORTB FUNCTIONS TABLE 9-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB Name Bit# Buffer Function RB0/INT0 bit0 TTL/ST(1) Input/output pin or external interrupt input0. Internal software programmable weak pull-up. RB1/INT1 bit1 TTL/ST(1) Input/output pin or external interrupt input1. Internal software programmable weak pull-up. RB2/INT2 bit2 TTL/ST(1) Input/output pin or external interrupt input2. Internal software programmable weak pull-up. RB3/CCP2(3) bit3 TTL/ST(4) Input/output pin or Capture2 input/Compare2 output/PWM output when CCP2MX configuration bit is enabled. Internal software programmable weak pull-up. RB4 bit4 TTL Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. RB5/PGM(5) bit5 TTL/ST(2) Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Low voltage ICSP enable pin. RB6/PGC bit6 TTL/ST(2) Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Serial programming clock. RB7/PGD bit7 TTL/ST(2) Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Serial programming data. Legend: TTL = TTL input, ST = Schmitt Trigger input Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt. 2: This buffer is a Schmitt Trigger input when used in Serial Programming mode. 3: A device configuration bit selects which I/O pin the CCP2 pin is multiplexed on. 4: This buffer is a Schmitt Trigger input when configured as the CCP2 input. 5: Low Voltage ICSP Programming (LVP) is enabled by default, which disables the RB5 I/O function. LVP must be disabled to enable RB5 as an I/O pin and allow maximum compatibility to the other 28-pin and 40-pin mid-range devices. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx uuuu uuuu LATB LATB Data Output Register xxxx xxxx uuuu uuuu TRISB PORTB Data Direction Register 1111 1111 1111 1111 INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RBIP 1111 -1-1 1111 -1-1 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 11-0 0-00 Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.© 2006 Microchip Technology Inc. DS39564C-page 93 PIC18FXX2 9.3 PORTC, TRISC and LATC Registers PORTC is an 8-bit wide, bi-directional port. The corresponding Data Direction register is TRISC. Setting a TRISC bit (= 1) will make the corresponding PORTC pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATC) is also memory mapped. Read-modify-write operations on the LATC register reads and writes the latched output value for PORTC. PORTC is multiplexed with several peripheral functions (Table 9-5). PORTC pins have Schmitt Trigger input buffers. When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for the correct TRIS bit settings. The pin override value is not loaded into the TRIS register. This allows read-modify-write of the TRIS register, without concern due to peripheral overrides. RC1 is normally configured by configuration bit, CCP2MX, as the default peripheral pin of the CCP2 module (default/erased state, CCP2MX = ’1’). EXAMPLE 9-3: INITIALIZING PORTC FIGURE 9-7: PORTC BLOCK DIAGRAM (PERIPHERAL OUTPUT OVERRIDE) Note: On a Power-on Reset, these pins are configured as digital inputs. CLRF PORTC ; Initialize PORTC by ; clearing output ; data latches CLRF LATC ; Alternate method ; to clear output ; data latches MOVLW 0xCF ; Value used to ; initialize data ; direction MOVWF TRISC ; Set RC<3:0> as inputs ; RC<5:4> as outputs ; RC<7:6> as inputs Data Bus WR LATC or WR TRISC RD TRISC D Q CK Q Q D EN Peripheral Data Out 0 1 D Q CK Q RD PORTC Peripheral Data In WR PORTC RD LATC Peripheral Output Schmitt Port/Peripheral Select(2) Enable(3) P N VSS VDD I/O pin(1) Note 1: I/O pins have diode protection to VDD and VSS. 2: Port/Peripheral Select signal selects between port data (input) and peripheral output. 3: Peripheral Output Enable is only active if peripheral select is active. Data Latch TRIS Latch TriggerPIC18FXX2 DS39564C-page 94 © 2006 Microchip Technology Inc. TABLE 9-5: PORTC FUNCTIONS TABLE 9-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC Name Bit# Buffer Type Function RC0/T1OSO/T1CKI bit0 ST Input/output port pin or Timer1 oscillator output/Timer1 clock input. RC1/T1OSI/CCP2 bit1 ST Input/output port pin, Timer1 oscillator input, or Capture2 input/ Compare2 output/PWM output when CCP2MX configuration bit is set. RC2/CCP1 bit2 ST Input/output port pin or Capture1 input/Compare1 output/PWM1 output. RC3/SCK/SCL bit3 ST RC3 can also be the synchronous serial clock for both SPI and I2C modes. RC4/SDI/SDA bit4 ST RC4 can also be the SPI Data In (SPI mode) or Data I/O (I2C mode). RC5/SDO bit5 ST Input/output port pin or Synchronous Serial Port data output. RC6/TX/CK bit6 ST Input/output port pin, Addressable USART Asynchronous Transmit, or Addressable USART Synchronous Clock. RC7/RX/DT bit7 ST Input/output port pin, Addressable USART Asynchronous Receive, or Addressable USART Synchronous Data. Legend: ST = Schmitt Trigger input Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx uuuu uuuu LATC LATC Data Output Register xxxx xxxx uuuu uuuu TRISC PORTC Data Direction Register 1111 1111 1111 1111 Legend: x = unknown, u = unchanged© 2006 Microchip Technology Inc. DS39564C-page 95 PIC18FXX2 9.4 PORTD, TRISD and LATD Registers This section is applicable only to the PIC18F4X2 devices. PORTD is an 8-bit wide, bi-directional port. The corresponding Data Direction register is TRISD. Setting a TRISD bit (= 1) will make the corresponding PORTD pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISD bit (= 0) will make the corresponding PORTD pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATD) is also memory mapped. Read-modify-write operations on the LATD register reads and writes the latched output value for PORTD. PORTD is an 8-bit port with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. PORTD can be configured as an 8-bit wide microprocessor port (parallel slave port) by setting control bit PSPMODE (TRISE<4>). In this mode, the input buffers are TTL. See Section 9.6 for additional information on the Parallel Slave Port (PSP). EXAMPLE 9-4: INITIALIZING PORTD FIGURE 9-8: PORTD BLOCK DIAGRAM IN I/O PORT MODE Note: On a Power-on Reset, these pins are configured as digital inputs. CLRF PORTD ; Initialize PORTD by ; clearing output ; data latches CLRF LATD ; Alternate method ; to clear output ; data latches MOVLW 0xCF ; Value used to ; initialize data ; direction MOVWF TRISD ; Set RD<3:0> as inputs ; RD<5:4> as outputs ; RD<7:6> as inputs Data Bus WR LATD WR TRISD RD PORTD Data Latch TRIS Latch RD TRISD Schmitt Trigger Input Buffer I/O pin(1) D Q CK D Q CK EN Q D EN RD LATD or PORTD Note 1: I/O pins have diode protection to VDD and VSS.PIC18FXX2 DS39564C-page 96 © 2006 Microchip Technology Inc. TABLE 9-7: PORTD FUNCTIONS TABLE 9-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD Name Bit# Buffer Type Function RD0/PSP0 bit0 ST/TTL(1) Input/output port pin or parallel slave port bit0. RD1/PSP1 bit1 ST/TTL(1) Input/output port pin or parallel slave port bit1. RD2/PSP2 bit2 ST/TTL(1) Input/output port pin or parallel slave port bit2. RD3/PSP3 bit3 ST/TTL(1) Input/output port pin or parallel slave port bit3. RD4/PSP4 bit4 ST/TTL(1) Input/output port pin or parallel slave port bit4. RD5/PSP5 bit5 ST/TTL(1) Input/output port pin or parallel slave port bit5. RD6/PSP6 bit6 ST/TTL(1) Input/output port pin or parallel slave port bit6. RD7/PSP7 bit7 ST/TTL(1) Input/output port pin or parallel slave port bit7. Legend: ST = Schmitt Trigger input, TTL = TTL input Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffer when in Parallel Slave Port mode. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx uuuu uuuu LATD LATD Data Output Register xxxx xxxx uuuu uuuu TRISD PORTD Data Direction Register 1111 1111 1111 1111 TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111 Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTD.© 2006 Microchip Technology Inc. DS39564C-page 97 PIC18FXX2 9.5 PORTE, TRISE and LATE Registers This section is only applicable to the PIC18F4X2 devices. PORTE is a 3-bit wide, bi-directional port. The corresponding Data Direction register is TRISE. Setting a TRISE bit (= 1) will make the corresponding PORTE pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISE bit (= 0) will make the corresponding PORTE pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATE) is also memory mapped. Read-modify-write operations on the LATE register reads and writes the latched output value for PORTE. PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6 and RE2/CS/AN7) which are individually configurable as inputs or outputs. These pins have Schmitt Trigger input buffers. Register 9-1 shows the TRISE register, which also controls the parallel slave port operation. PORTE pins are multiplexed with analog inputs. When selected as an analog input, these pins will read as '0's. TRISE controls the direction of the RE pins, even when they are being used as analog inputs. The user must make sure to keep the pins configured as inputs when using them as analog inputs. EXAMPLE 9-5: INITIALIZING PORTE FIGURE 9-9: PORTE BLOCK DIAGRAM IN I/O PORT MODE Note: On a Power-on Reset, these pins are configured as analog inputs. CLRF PORTE ; Initialize PORTE by ; clearing output ; data latches CLRF LATE ; Alternate method ; to clear output ; data latches MOVLW 0x07 ; Configure A/D MOVWF ADCON1 ; for digital inputs MOVLW 0x05 ; Value used to ; initialize data ; direction MOVWF TRISE ; Set RE<0> as inputs ; RE<1> as outputs ; RE<2> as inputs Data Bus WR LATE WR TRISE RD PORTE Data Latch TRIS Latch RD TRISE Schmitt Trigger Input Buffer D Q CK D Q CK EN Q D EN I/O pin(1) RD LATE or PORTE To Analog Converter Note 1: I/O pins have diode protection to VDD and VSS.PIC18FXX2 DS39564C-page 98 © 2006 Microchip Technology Inc. REGISTER 9-1: TRISE REGISTER R-0 R-0 R/W-0 R/W-0 U-0 R/W-1 R/W-1 R/W-1 IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0 bit 7 bit 0 bit 7 IBF: Input Buffer Full Status bit 1 = A word has been received and waiting to be read by the CPU 0 = No word has been received bit 6 OBF: Output Buffer Full Status bit 1 = The output buffer still holds a previously written word 0 = The output buffer has been read bit 5 IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode) 1 = A write occurred when a previously input word has not been read (must be cleared in software) 0 = No overflow occurred bit 4 PSPMODE: Parallel Slave Port Mode Select bit 1 = Parallel Slave Port mode 0 = General purpose I/O mode bit 3 Unimplemented: Read as '0' bit 2 TRISE2: RE2 Direction Control bit 1 = Input 0 = Output bit 1 TRISE1: RE1 Direction Control bit 1 = Input 0 = Output bit 0 TRISE0: RE0 Direction Control bit 1 = Input 0 = Output Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 99 PIC18FXX2 TABLE 9-9: PORTE FUNCTIONS TABLE 9-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE Name Bit# Buffer Type Function RE0/RD/AN5 bit0 ST/TTL(1) Input/output port pin or read control input in Parallel Slave Port mode or analog input: RD 1 = Not a read operation 0 = Read operation. Reads PORTD register (if chip selected). RE1/WR/AN6 bit1 ST/TTL(1) Input/output port pin or write control input in Parallel Slave Port mode or analog input: WR 1 = Not a write operation 0 = Write operation. Writes PORTD register (if chip selected). RE2/CS/AN7 bit2 ST/TTL(1) Input/output port pin or chip select control input in Parallel Slave Port mode or analog input: CS 1 = Device is not selected 0 = Device is selected Legend: ST = Schmitt Trigger input, TTL = TTL input Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS PORTE — — — — — RE2 RE1 RE0 ---- -000 ---- -000 LATE — — — — — LATE Data Output Register ---- -xxx ---- -uuu TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111 ADCON1 ADFM ADCS2 — — PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 00-- 0000 Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTE.PIC18FXX2 DS39564C-page 100 © 2006 Microchip Technology Inc. 9.6 Parallel Slave Port The Parallel Slave Port is implemented on the 40-pin devices only (PIC18F4X2). PORTD operates as an 8-bit wide Parallel Slave Port, or microprocessor port when control bit, PSPMODE (TRISE<4>) is set. It is asynchronously readable and writable by the external world through RD control input pin, RE0/RD and WR control input pin, RE1/WR. It can directly interface to an 8-bit microprocessor data bus. The external microprocessor can read or write the PORTD latch as an 8-bit latch. Setting bit PSPMODE enables port pin RE0/RD to be the RD input, RE1/WR to be the WR input and RE2/CS to be the CS (chip select) input. For this functionality, the corresponding data direction bits of the TRISE register (TRISE<2:0>) must be configured as inputs (set). The A/D port configuration bits PCFG2:PCFG0 (ADCON1<2:0>) must be set, which will configure pins RE2:RE0 as digital I/O. A write to the PSP occurs when both the CS and WR lines are first detected low. A read from the PSP occurs when both the CS and RD lines are first detected low. The PORTE I/O pins become control inputs for the microprocessor port when bit PSPMODE (TRISE<4>) is set. In this mode, the user must make sure that the TRISE<2:0> bits are set (pins are configured as digital inputs), and the ADCON1 is configured for digital I/O. In this mode, the input buffers are TTL. FIGURE 9-10: PORTD AND PORTE BLOCK DIAGRAM (PARALLEL SLAVE PORT) FIGURE 9-11: PARALLEL SLAVE PORT WRITE WAVEFORMS Data Bus WR LATD RDx D Q CK EN Q D RD PORTD EN Pin One bit of PORTD Set Interrupt Flag PSPIF (PIR1<7>) Read Chip Select Write RD CS WR Note: I/O pin has protection diodes to VDD and VSS. TTL TTL TTL TTL or PORTD RD LATD Data Latch TRIS Latch Q1 Q2 Q3 Q4 CS Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 WR RD IBF OBF PSPIF PORTD<7:0>© 2006 Microchip Technology Inc. DS39564C-page 101 PIC18FXX2 FIGURE 9-12: PARALLEL SLAVE PORT READ WAVEFORMS TABLE 9-11: REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT Q1 Q2 Q3 Q4 CS Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 WR IBF PSPIF RD OBF PORTD<7:0> Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS PORTD Port Data Latch when written; Port pins when read xxxx xxxx uuuu uuuu LATD LATD Data Output bits xxxx xxxx uuuu uuuu TRISD PORTD Data Direction bits 1111 1111 1111 1111 PORTE — — — — — RE2 RE1 RE0 ---- -000 ---- -000 LATE — — — — — LATE Data Output bits ---- -xxx ---- -uuu TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111 INTCON GIE/ GIEH PEIE/ GIEL TMR0IF INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 ADCON1 ADFM ADCS2 — — PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 00-- 0000 Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Parallel Slave Port.PIC18FXX2 DS39564C-page 102 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 103 PIC18FXX2 10.0 TIMER0 MODULE The Timer0 module has the following features: • Software selectable as an 8-bit or 16-bit timer/ counter • Readable and writable • Dedicated 8-bit software programmable prescaler • Clock source selectable to be external or internal • Interrupt-on-overflow from FFh to 00h in 8-bit mode and FFFFh to 0000h in 16-bit mode • Edge select for external clock Figure 10-1 shows a simplified block diagram of the Timer0 module in 8-bit mode and Figure 10-2 shows a simplified block diagram of the Timer0 module in 16-bit mode. The T0CON register (Register 10-1) is a readable and writable register that controls all the aspects of Timer0, including the prescale selection. REGISTER 10-1: T0CON: TIMER0 CONTROL REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 bit 7 bit 0 bit 7 TMR0ON: Timer0 On/Off Control bit 1 = Enables Timer0 0 = Stops Timer0 bit 6 T08BIT: Timer0 8-bit/16-bit Control bit 1 = Timer0 is configured as an 8-bit timer/counter 0 = Timer0 is configured as a 16-bit timer/counter bit 5 T0CS: Timer0 Clock Source Select bit 1 = Transition on T0CKI pin 0 = Internal instruction cycle clock (CLKO) bit 4 T0SE: Timer0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin bit 3 PSA: Timer0 Prescaler Assignment bit 1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler. 0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output. bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits 111 = 1:256 prescale value 110 = 1:128 prescale value 101 = 1:64 prescale value 100 = 1:32 prescale value 011 = 1:16 prescale value 010 = 1:8 prescale value 001 = 1:4 prescale value 000 = 1:2 prescale value Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 104 © 2006 Microchip Technology Inc. FIGURE 10-1: TIMER0 BLOCK DIAGRAM IN 8-BIT MODE FIGURE 10-2: TIMER0 BLOCK DIAGRAM IN 16-BIT MODE Note: Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. RA4/T0CKI pin T0SE 0 1 1 0 T0CS FOSC/4 Programmable Prescaler Sync with Internal Clocks TMR0L (2 TCY delay) Data Bus 8 PSA T0PS2, T0PS1, T0PS0 Set Interrupt Flag bit TMR0IF on Overflow 3 Note: Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. T0CKI pin T0SE 0 1 1 0 T0CS FOSC/4 Programmable Prescaler Sync with Internal Clocks TMR0L (2 TCY delay) Data Bus<7:0> 8 PSA T0PS2, T0PS1, T0PS0 Set Interrupt Flag bit TMR0IF on Overflow 3 TMR0 TMR0H High Byte 8 8 8 Read TMR0L Write TMR0L© 2006 Microchip Technology Inc. DS39564C-page 105 PIC18FXX2 10.1 Timer0 Operation Timer0 can operate as a timer or as a counter. Timer mode is selected by clearing the T0CS bit. In Timer mode, the Timer0 module will increment every instruction cycle (without prescaler). If the TMR0L register is written, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0L register. Counter mode is selected by setting the T0CS bit. In Counter mode, Timer0 will increment, either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit (T0SE). Clearing the T0SE bit selects the rising edge. Restrictions on the external clock input are discussed below. When an external clock input is used for Timer0, it must meet certain requirements. The requirements ensure the external clock can be synchronized with the internal phase clock (TOSC). Also, there is a delay in the actual incrementing of Timer0 after synchronization. 10.2 Prescaler An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not readable or writable. The PSA and T0PS2:T0PS0 bits determine the prescaler assignment and prescale ratio. Clearing bit PSA will assign the prescaler to the Timer0 module. When the prescaler is assigned to the Timer0 module, prescale values of 1:2, 1:4,..., 1:256 are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0L register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, x....etc.) will clear the prescaler count. 10.2.1 SWITCHING PRESCALER ASSIGNMENT The prescaler assignment is fully under software control, (i.e., it can be changed “on-the-fly” during program execution). 10.3 Timer0 Interrupt The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF bit. The interrupt can be masked by clearing the TMR0IE bit. The TMR0IE bit must be cleared in software by the Timer0 module Interrupt Service Routine before re-enabling this interrupt. The TMR0 interrupt cannot awaken the processor from SLEEP, since the timer is shut-off during SLEEP. 10.4 16-Bit Mode Timer Reads and Writes TMR0H is not the high byte of the timer/counter in 16-bit mode, but is actually a buffered version of the high byte of Timer0 (refer to Figure 10-2). The high byte of the Timer0 counter/timer is not directly readable nor writable. TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16-bits of Timer0 without having to verify that the read of the high and low byte were valid due to a rollover between successive reads of the high and low byte. A write to the high byte of Timer0 must also take place through the TMR0H buffer register. Timer0 high byte is updated with the contents of TMR0H when a write occurs to TMR0L. This allows all 16-bits of Timer0 to be updated at once. TABLE 10-1: REGISTERS ASSOCIATED WITH TIMER0 Note: Writing to TMR0L when the prescaler is assigned to Timer0 will clear the prescaler count, but will not change the prescaler assignment. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS TMR0L Timer0 Module Low Byte Register xxxx xxxx uuuu uuuu TMR0H Timer0 Module High Byte Register 0000 0000 0000 0000 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 1111 1111 TRISA — PORTA Data Direction Register -111 1111 -111 1111 Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0.PIC18FXX2 DS39564C-page 106 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 107 PIC18FXX2 11.0 TIMER1 MODULE The Timer1 module timer/counter has the following features: • 16-bit timer/counter (two 8-bit registers; TMR1H and TMR1L) • Readable and writable (both registers) • Internal or external clock select • Interrupt-on-overflow from FFFFh to 0000h • RESET from CCP module special event trigger Figure 11-1 is a simplified block diagram of the Timer1 module. Register 11-1 details the Timer1 control register. This register controls the Operating mode of the Timer1 module, and contains the Timer1 oscillator enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit TMR1ON (T1CON<0>). REGISTER 11-1: T1CON: TIMER1 CONTROL REGISTER R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON bit 7 bit 0 bit 7 RD16: 16-bit Read/Write Mode Enable bit 1 = Enables register Read/Write of Timer1 in one 16-bit operation 0 = Enables register Read/Write of Timer1 in two 8-bit operations bit 6 Unimplemented: Read as '0' bit 5-4 T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 3 T1OSCEN: Timer1 Oscillator Enable bit 1 = Timer1 Oscillator is enabled 0 = Timer1 Oscillator is shut-off The oscillator inverter and feedback resistor are turned off to eliminate power drain. bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. bit 1 TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge) 0 = Internal clock (FOSC/4) bit 0 TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 108 © 2006 Microchip Technology Inc. 11.1 Timer1 Operation Timer1 can operate in one of these modes: • As a timer • As a synchronous counter • As an asynchronous counter The Operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). When TMR1CS = 0, Timer1 increments every instruction cycle. When TMR1CS = 1, Timer1 increments on every rising edge of the external clock input or the Timer1 oscillator, if enabled. When the Timer1 oscillator is enabled (T1OSCEN is set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins become inputs. That is, the TRISC<1:0> value is ignored, and the pins are read as ‘0’. Timer1 also has an internal “RESET input”. This RESET can be generated by the CCP module (Section 14.0). FIGURE 11-1: TIMER1 BLOCK DIAGRAM FIGURE 11-2: TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE TMR1H TMR1L T1SYNC TMR1CS T1CKPS1:T1CKPS0 SLEEP Input FOSC/4 Internal Clock TMR1ON On/Off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 TMR1IF Overflow TMR1 CLR CCP Special Event Trigger T1OSCEN Enable Oscillator(1) T1OSC Interrupt Flag Bit Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. T1OSI T1CKI/T1OSO Timer 1 TMR1L T1OSC T1SYNC TMR1CS T1CKPS1:T1CKPS0 SLEEP Input T1OSCEN Enable Oscillator(1) TMR1IF Overflow Interrupt FOSC/4 Internal Clock TMR1ON on/off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 T13CKI/T1OSO T1OSI TMR1 Flag bit Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. High Byte Data Bus<7:0> 8 TMR1H 8 8 8 Read TMR1L Write TMR1L CLR CCP Special Event Trigger© 2006 Microchip Technology Inc. DS39564C-page 109 PIC18FXX2 11.2 Timer1 Oscillator A crystal oscillator circuit is built-in between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting control bit T1OSCEN (T1CON<3>). The oscillator is a low power oscillator rated up to 200 kHz. It will continue to run during SLEEP. It is primarily intended for a 32 kHz crystal. Table 11-1 shows the capacitor selection for the Timer1 oscillator. The user must provide a software time delay to ensure proper start-up of the Timer1 oscillator. TABLE 11-1: CAPACITOR SELECTION FOR THE ALTERNATE OSCILLATOR 11.3 Timer1 Interrupt The TMR1 Register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR1 Interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit TMR1IF (PIR1<0>). This interrupt can be enabled/disabled by setting/ clearing TMR1 interrupt enable bit, TMR1IE (PIE1<0>). 11.4 Resetting Timer1 using a CCP Trigger Output If the CCP module is configured in Compare mode to generate a “special event trigger” (CCP1M3:CCP1M0 = 1011), this signal will reset Timer1 and start an A/D conversion (if the A/D module is enabled). Timer1 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer1 is running in Asynchronous Counter mode, this RESET operation may not work. In the event that a write to Timer1 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPR1H:CCPR1L registers pair effectively becomes the period register for Timer1. 11.5 Timer1 16-Bit Read/Write Mode Timer1 can be configured for 16-bit reads and writes (see Figure 11-2). When the RD16 control bit (T1CON<7>) is set, the address for TMR1H is mapped to a buffer register for the high byte of Timer1. A read from TMR1L will load the contents of the high byte of Timer1 into the Timer1 high byte buffer. This provides the user with the ability to accurately read all 16-bits of Timer1 without having to determine whether a read of the high byte followed by a read of the low byte is valid, due to a rollover between reads. A write to the high byte of Timer1 must also take place through the TMR1H buffer register. Timer1 high byte is updated with the contents of TMR1H when a write occurs to TMR1L. This allows a user to write all 16 bits to both the high and low bytes of Timer1 at once. The high byte of Timer1 is not directly readable or writable in this mode. All reads and writes must take place through the Timer1 high byte buffer register. Writes to TMR1H do not clear the Timer1 prescaler. The prescaler is only cleared on writes to TMR1L. Osc Type Freq C1 C2 LP 32 kHz TBD(1) TBD(1) Crystal to be Tested: 32.768 kHz Epson C-001R32.768K-A ± 20 PPM Note 1: Microchip suggests 33 pF as a starting point in validating the oscillator circuit. 2: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Capacitor values are for design guidance only. Note: The special event triggers from the CCP1 module will not set interrupt flag bit TMR1IF (PIR1<0>). PIC18FXX2 DS39564C-page 110 © 2006 Microchip Technology Inc. TABLE 11-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.© 2006 Microchip Technology Inc. DS39564C-page 111 PIC18FXX2 12.0 TIMER2 MODULE The Timer2 module timer has the following features: • 8-bit timer (TMR2 register) • 8-bit period register (PR2) • Readable and writable (both registers) • Software programmable prescaler (1:1, 1:4, 1:16) • Software programmable postscaler (1:1 to 1:16) • Interrupt on TMR2 match of PR2 • SSP module optional use of TMR2 output to generate clock shift Timer2 has a control register shown in Register 12-1. Timer2 can be shut-off by clearing control bit TMR2ON (T2CON<2>) to minimize power consumption. Figure 12-1 is a simplified block diagram of the Timer2 module. Register 12-1 shows the Timer2 control register. The prescaler and postscaler selection of Timer2 are controlled by this register. 12.1 Timer2 Operation Timer2 can be used as the PWM time-base for the PWM mode of the CCP module. The TMR2 register is readable and writable, and is cleared on any device RESET. The input clock (FOSC/4) has a prescale option of 1:1, 1:4 or 1:16, selected by control bits T2CKPS1:T2CKPS0 (T2CON<1:0>). The match output of TMR2 goes through a 4-bit postscaler (which gives a 1:1 to 1:16 scaling inclusive) to generate a TMR2 interrupt (latched in flag bit TMR2IF, (PIR1<1>)). The prescaler and postscaler counters are cleared when any of the following occurs: • a write to the TMR2 register • a write to the T2CON register • any device RESET (Power-on Reset, MCLR Reset, Watchdog Timer Reset, or Brown-out Reset) TMR2 is not cleared when T2CON is written. REGISTER 12-1: T2CON: TIMER2 CONTROL REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 bit 7 bit 0 bit 7 Unimplemented: Read as '0' bit 6-3 TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale • • • 1111 = 1:16 Postscale bit 2 TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off bit 1-0 T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 112 © 2006 Microchip Technology Inc. 12.2 Timer2 Interrupt The Timer2 module has an 8-bit period register, PR2. Timer2 increments from 00h until it matches PR2 and then resets to 00h on the next increment cycle. PR2 is a readable and writable register. The PR2 register is initialized to FFh upon RESET. 12.3 Output of TMR2 The output of TMR2 (before the postscaler) is fed to the Synchronous Serial Port module, which optionally uses it to generate the shift clock. FIGURE 12-1: TIMER2 BLOCK DIAGRAM TABLE 12-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER Comparator TMR2 Sets Flag TMR2 Output(1) RESET Postscaler Prescaler PR2 2 FOSC/4 1:1 to 1:16 1:1, 1:4, 1:16 EQ 4 bit TMR2IF Note 1: TMR2 register output can be software selected by the SSP Module as a baud clock. TOUTPS3:TOUTPS0 T2CKPS1:T2CKPS0 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 TMR2 Timer2 Module Register 0000 0000 0000 0000 T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 PR2 Timer2 Period Register 1111 1111 1111 1111 Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the Timer2 module. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.© 2006 Microchip Technology Inc. DS39564C-page 113 PIC18FXX2 13.0 TIMER3 MODULE The Timer3 module timer/counter has the following features: • 16-bit timer/counter (two 8-bit registers; TMR3H and TMR3L) • Readable and writable (both registers) • Internal or external clock select • Interrupt-on-overflow from FFFFh to 0000h • RESET from CCP module trigger Figure 13-1 is a simplified block diagram of the Timer3 module. Register 13-1 shows the Timer3 control register. This register controls the Operating mode of the Timer3 module and sets the CCP clock source. Register 11-1 shows the Timer1 control register. This register controls the Operating mode of the Timer1 module, as well as contains the Timer1 oscillator enable bit (T1OSCEN), which can be a clock source for Timer3. REGISTER 13-1: T3CON: TIMER3 CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON bit 7 bit 0 bit 7 RD16: 16-bit Read/Write Mode Enable bit 1 = Enables register Read/Write of Timer3 in one 16-bit operation 0 = Enables register Read/Write of Timer3 in two 8-bit operations bit 6-3 T3CCP2:T3CCP1: Timer3 and Timer1 to CCPx Enable bits 1x = Timer3 is the clock source for compare/capture CCP modules 01 = Timer3 is the clock source for compare/capture of CCP2, Timer1 is the clock source for compare/capture of CCP1 00 = Timer1 is the clock source for compare/capture CCP modules bit 5-4 T3CKPS1:T3CKPS0: Timer3 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the system clock comes from Timer1/Timer3) When TMR3CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR3CS = 0: This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0. bit 1 TMR3CS: Timer3 Clock Source Select bit 1 = External clock input from Timer1 oscillator or T1CKI (on the rising edge after the first falling edge) 0 = Internal clock (FOSC/4) bit 0 TMR3ON: Timer3 On bit 1 = Enables Timer3 0 = Stops Timer3 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 114 © 2006 Microchip Technology Inc. 13.1 Timer3 Operation Timer3 can operate in one of these modes: • As a timer • As a synchronous counter • As an asynchronous counter The Operating mode is determined by the clock select bit, TMR3CS (T3CON<1>). When TMR3CS = 0, Timer3 increments every instruction cycle. When TMR3CS = 1, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. When the Timer1 oscillator is enabled (T1OSCEN is set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins become inputs. That is, the TRISC<1:0> value is ignored, and the pins are read as ‘0’. Timer3 also has an internal “RESET input”. This RESET can be generated by the CCP module (Section 14.0). FIGURE 13-1: TIMER3 BLOCK DIAGRAM FIGURE 13-2: TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE TMR3H TMR3L T1OSC T3SYNC TMR3CS T3CKPS1:T3CKPS0 SLEEP Input T1OSCEN Enable Oscillator(1) TMR3IF Overflow Interrupt FOSC/4 Internal Clock TMR3ON On/Off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 T1OSO/ T1OSI Flag bit (3) Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. T13CKI CLR CCP Special Trigger T3CCPx Timer3 TMR3L T1OSC T3SYNC TMR3CS T3CKPS1:T3CKPS0 SLEEP Input T1OSCEN Enable Oscillator(1) FOSC/4 Internal Clock TMR3ON On/Off Prescaler 1, 2, 4, 8 Synchronize det 1 0 0 1 Synchronized Clock Input 2 T1OSO/ T1OSI TMR3 T13CKI CLR CCP Special Trigger T3CCPx To Timer1 Clock Input Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain. High Byte Data Bus<7:0> 8 TMR3H 8 8 8 Read TMR3L Write TMR3L Set TMR3IF Flag bit on Overflow© 2006 Microchip Technology Inc. DS39564C-page 115 PIC18FXX2 13.2 Timer1 Oscillator The Timer1 oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN (T1CON<3>) bit. The oscillator is a low power oscillator rated up to 200 KHz. See Section 11.0 for further details. 13.3 Timer3 Interrupt The TMR3 Register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR3 Interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR3IF (PIR2<1>). This interrupt can be enabled/disabled by setting/clearing TMR3 interrupt enable bit, TMR3IE (PIE2<1>). 13.4 Resetting Timer3 Using a CCP Trigger Output If the CCP module is configured in Compare mode to generate a “special event trigger” (CCP1M3:CCP1M0 = 1011), this signal will reset Timer3. Timer3 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer3 is running in Asynchronous Counter mode, this RESET operation may not work. In the event that a write to Timer3 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPR1H:CCPR1L registers pair effectively becomes the period register for Timer3. TABLE 13-1: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER Note: The special event triggers from the CCP module will not set interrupt flag bit, TMR3IF (PIR1<0>). Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000 PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000 IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111 TMR3L Holding Register for the Least Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu TMR3H Holding Register for the Most Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 uuuu uuuu Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.PIC18FXX2 DS39564C-page 116 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 117 PIC18FXX2 14.0 CAPTURE/COMPARE/PWM (CCP) MODULES Each CCP (Capture/Compare/PWM) module contains a 16-bit register which can operate as a 16-bit Capture register, as a 16-bit Compare register or as a PWM Master/Slave Duty Cycle register. Table 14-1 shows the timer resources of the CCP Module modes. The operation of CCP1 is identical to that of CCP2, with the exception of the special event trigger. Therefore, operation of a CCP module in the following sections is described with respect to CCP1. Table 14-2 shows the interaction of the CCP modules. REGISTER 14-1: CCP1CON REGISTER/CCP2CON REGISTER U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0 bit 7 bit 0 bit 7-6 Unimplemented: Read as '0' bit 5-4 DCxB1:DCxB0: PWM Duty Cycle bit1 and bit0 Capture mode: Unused Compare mode: Unused PWM mode: These bits are the two LSbs (bit1 and bit0) of the 10-bit PWM duty cycle. The upper eight bits (DCx9:DCx2) of the duty cycle are found in CCPRxL. bit 3-0 CCPxM3:CCPxM0: CCPx Mode Select bits 0000 = Capture/Compare/PWM disabled (resets CCPx module) 0001 = Reserved 0010 = Compare mode, toggle output on match (CCPxIF bit is set) 0011 = Reserved 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode, Initialize CCP pin Low, on compare match force CCP pin High (CCPIF bit is set) 1001 = Compare mode, Initialize CCP pin High, on compare match force CCP pin Low (CCPIF bit is set) 1010 = Compare mode, Generate software interrupt on compare match (CCPIF bit is set, CCP pin is unaffected) 1011 = Compare mode, Trigger special event (CCPIF bit is set) 11xx = PWM mode Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 118 © 2006 Microchip Technology Inc. 14.1 CCP1 Module Capture/Compare/PWM Register 1 (CCPR1) is comprised of two 8-bit registers: CCPR1L (low byte) and CCPR1H (high byte). The CCP1CON register controls the operation of CCP1. All are readable and writable. TABLE 14-1: CCP MODE - TIMER RESOURCE 14.2 CCP2 Module Capture/Compare/PWM Register2 (CCPR2) is comprised of two 8-bit registers: CCPR2L (low byte) and CCPR2H (high byte). The CCP2CON register controls the operation of CCP2. All are readable and writable. TABLE 14-2: INTERACTION OF TWO CCP MODULES CCP Mode Timer Resource Capture Compare PWM Timer1 or Timer3 Timer1 or Timer3 Timer2 CCPx Mode CCPy Mode Interaction Capture Capture TMR1 or TMR3 time-base. Time-base can be different for each CCP. Capture Compare The compare could be configured for the special event trigger, which clears either TMR1 or TMR3 depending upon which time-base is used. Compare Compare The compare(s) could be configured for the special event trigger, which clears TMR1 or TMR3 depending upon which time-base is used. PWM PWM The PWMs will have the same frequency and update rate (TMR2 interrupt). PWM Capture None PWM Compare None© 2006 Microchip Technology Inc. DS39564C-page 119 PIC18FXX2 14.3 Capture Mode In Capture mode, CCPR1H:CCPR1L captures the 16-bit value of the TMR1 or TMR3 registers when an event occurs on pin RC2/CCP1. An event is defined as one of the following: • every falling edge • every rising edge • every 4th rising edge • every 16th rising edge The event is selected by control bits CCP1M3:CCP1M0 (CCP1CON<3:0>). When a capture is made, the interrupt request flag bit CCP1IF (PIR1<2>) is set; it must be cleared in software. If another capture occurs before the value in register CCPR1 is read, the old captured value is overwritten by the new captured value. 14.3.1 CCP PIN CONFIGURATION In Capture mode, the RC2/CCP1 pin should be configured as an input by setting the TRISC<2> bit. 14.3.2 TIMER1/TIMER3 MODE SELECTION The timers that are to be used with the capture feature (either Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation may not work. The timer to be used with each CCP module is selected in the T3CON register. 14.3.3 SOFTWARE INTERRUPT When the Capture mode is changed, a false capture interrupt may be generated. The user should keep bit CCP1IE (PIE1<2>) clear to avoid false interrupts and should clear the flag bit, CCP1IF, following any such change in Operating mode. 14.3.4 CCP PRESCALER There are four prescaler settings, specified by bits CCP1M3:CCP1M0. Whenever the CCP module is turned off or the CCP module is not in Capture mode, the prescaler counter is cleared. This means that any RESET will clear the prescaler counter. Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared, therefore, the first capture may be from a non-zero prescaler. Example 14-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the “false” interrupt. EXAMPLE 14-1: CHANGING BETWEEN CAPTURE PRESCALERS FIGURE 14-1: CAPTURE MODE OPERATION BLOCK DIAGRAM Note: If the RC2/CCP1 is configured as an output, a write to the port can cause a capture condition. CLRF CCP1CON, F ; Turn CCP module off MOVLW NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON MOVWF CCP1CON ; Load CCP1CON with ; this value CCPR1H CCPR1L TMR1H TMR1L Set Flag bit CCP1IF TMR3 Enable Q’s CCP1CON<3:0> CCP1 pin Prescaler ÷ 1, 4, 16 and Edge Detect TMR3H TMR3L TMR1 Enable T3CCP2 T3CCP2 CCPR2H CCPR2L TMR1H TMR1L Set Flag bit CCP2IF TMR3 Enable Q’s CCP2CON<3:0> CCP2 pin Prescaler ÷ 1, 4, 16 and Edge Detect TMR3H TMR3L TMR1 Enable T3CCP2 T3CCP1 T3CCP2 T3CCP1PIC18FXX2 DS39564C-page 120 © 2006 Microchip Technology Inc. 14.4 Compare Mode In Compare mode, the 16-bit CCPR1 (CCPR2) register value is constantly compared against either the TMR1 register pair value, or the TMR3 register pair value. When a match occurs, the RC2/CCP1 (RC1/CCP2) pin is: • driven High • driven Low • toggle output (High to Low or Low to High) • remains unchanged The action on the pin is based on the value of control bits CCP1M3:CCP1M0 (CCP2M3:CCP2M0). At the same time, interrupt flag bit CCP1IF (CCP2IF) is set. 14.4.1 CCP PIN CONFIGURATION The user must configure the CCPx pin as an output by clearing the appropriate TRISC bit. 14.4.2 TIMER1/TIMER3 MODE SELECTION Timer1 and/or Timer3 must be running in Timer mode or Synchronized Counter mode if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work. 14.4.3 SOFTWARE INTERRUPT MODE When generate software interrupt is chosen, the CCP1 pin is not affected. Only a CCP interrupt is generated (if enabled). 14.4.4 SPECIAL EVENT TRIGGER In this mode, an internal hardware trigger is generated, which may be used to initiate an action. The special event trigger output of CCP1 resets the TMR1 register pair. This allows the CCPR1 register to effectively be a 16-bit programmable period register for Timer1. The special trigger output of CCPx resets either the TMR1 or TMR3 register pair. Additionally, the CCP2 Special Event Trigger will start an A/D conversion if the A/D module is enabled. FIGURE 14-2: COMPARE MODE OPERATION BLOCK DIAGRAM Note: Clearing the CCP1CON register will force the RC2/CCP1 compare output latch to the default low level. This is not the PORTC I/O data latch. Note: The special event trigger from the CCP2 module will not set the Timer1 or Timer3 interrupt flag bits. CCPR1H CCPR1L TMR1H TMR1L Comparator Q S R Output Logic Special Event Trigger Set Flag bit CCP1IF RC2/CCP1 pin Match TRISC<2> CCP1CON<3:0> Mode Select Output Enable Special Event Trigger will: Reset Timer1 or Timer3, but not set Timer1 or Timer3 interrupt flag bit, and set bit GO/DONE (ADCON0<2>) which starts an A/D conversion (CCP2 only) TMR3H TMR3L T3CCP2 CCPR2H CCPR2L Comparator 0 1 T3CCP2 T3CCP1 Q S R Output Logic Special Event Trigger Set Flag bit CCP2IF RC1/CCP2 pin Match TRISC<1> CCP2CON<3:0> Mode Select Output Enable 0 1© 2006 Microchip Technology Inc. DS39564C-page 121 PIC18FXX2 TABLE 14-3: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 TRISC PORTC Data Direction Register 1111 1111 1111 1111 TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu CCPR1L Capture/Compare/PWM Register1 (LSB) xxxx xxxx uuuu uuuu CCPR1H Capture/Compare/PWM Register1 (MSB) xxxx xxxx uuuu uuuu CCP1CON — — DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000 CCPR2L Capture/Compare/PWM Register2 (LSB) xxxx xxxx uuuu uuuu CCPR2H Capture/Compare/PWM Register2 (MSB) xxxx xxxx uuuu uuuu CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000 PIR2 — — — EEIE BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000 PIE2 — — — EEIF BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000 IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111 TMR3L Holding Register for the Least Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu TMR3H Holding Register for the Most Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 uuuu uuuu Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Capture and Timer1. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2x2 devices; always maintain these bits clear.PIC18FXX2 DS39564C-page 122 © 2006 Microchip Technology Inc. 14.5 PWM Mode In Pulse Width Modulation (PWM) mode, the CCP1 pin produces up to a 10-bit resolution PWM output. Since the CCP1 pin is multiplexed with the PORTC data latch, the TRISC<2> bit must be cleared to make the CCP1 pin an output. Figure 14-3 shows a simplified block diagram of the CCP module in PWM mode. For a step-by-step procedure on how to set up the CCP module for PWM operation, see Section 14.5.3. FIGURE 14-3: SIMPLIFIED PWM BLOCK DIAGRAM A PWM output (Figure 14-4) has a time-base (period) and a time that the output stays high (duty cycle). The frequency of the PWM is the inverse of the period (1/period). FIGURE 14-4: PWM OUTPUT 14.5.1 PWM PERIOD The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula: PWM period = (PR2) + 1] • 4 • TOSC • (TMR2 prescale value) PWM frequency is defined as 1 / [PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: • TMR2 is cleared • The CCP1 pin is set (exception: if PWM duty cycle = 0%, the CCP1 pin will not be set) • The PWM duty cycle is latched from CCPR1L into CCPR1H 14.5.2 PWM DUTY CYCLE The PWM duty cycle is specified by writing to the CCPR1L register and to the CCP1CON<5:4> bits. Up to 10-bit resolution is available. The CCPR1L contains the eight MSbs and the CCP1CON<5:4> contains the two LSbs. This 10-bit value is represented by CCPR1L:CCP1CON<5:4>. The following equation is used to calculate the PWM duty cycle in time: PWM duty cycle = (CCPR1L:CCP1CON<5:4>) • TOSC • (TMR2 prescale value) CCPR1L and CCP1CON<5:4> can be written to at any time, but the duty cycle value is not latched into CCPR1H until after a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR1H is a read only register. The CCPR1H register and a 2-bit internal latch are used to double buffer the PWM duty cycle. This double buffering is essential for glitchless PWM operation. When the CCPR1H and 2-bit latch match TMR2 concatenated with an internal 2-bit Q clock or 2 bits of the TMR2 prescaler, the CCP1 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the equation: Note: Clearing the CCP1CON register will force the CCP1 PWM output latch to the default low level. This is not the PORTC I/O data latch. CCPR1L CCPR1H (Slave) Comparator TMR2 Comparator PR2 (Note 1) R Q S Duty Cycle Registers CCP1CON<5:4> Clear Timer, CCP1 pin and latch D.C. TRISC<2> RC2/CCP1 Note: 8-bit timer is concatenated with 2-bit internal Q clock or 2 bits of the prescaler to create 10-bit time-base. Period Duty Cycle TMR2 = PR2 TMR2 = Duty Cycle TMR2 = PR2 Note: The Timer2 postscaler (see Section 12.0) is not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output. Note: If the PWM duty cycle value is longer than the PWM period, the CCP1 pin will not be cleared. FOSC FPWM --------------- ⎝ ⎠ ⎛ ⎞ log log( ) 2 PWM Resolution (max) = -----------------------------bits© 2006 Microchip Technology Inc. DS39564C-page 123 PIC18FXX2 14.5.3 SETUP FOR PWM OPERATION The following steps should be taken when configuring the CCP module for PWM operation: 1. Set the PWM period by writing to the PR2 register. 2. Set the PWM duty cycle by writing to the CCPR1L register and CCP1CON<5:4> bits. 3. Make the CCP1 pin an output by clearing the TRISC<2> bit. 4. Set the TMR2 prescale value and enable Timer2 by writing to T2CON. 5. Configure the CCP1 module for PWM operation. TABLE 14-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz TABLE 14-5: REGISTERS ASSOCIATED WITH PWM AND TIMER2 PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz Timer Prescaler (1, 4, 16) 16 4 1 1 1 1 PR2 Value 0xFF 0xFF 0xFF 0x3F 0x1F 0x17 Maximum Resolution (bits) 14 12 10 8 7 6.58 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 TRISC PORTC Data Direction Register 1111 1111 1111 1111 TMR2 Timer2 Module Register 0000 0000 0000 0000 PR2 Timer2 Module Period Register 1111 1111 1111 1111 T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 CCPR1L Capture/Compare/PWM Register1 (LSB) xxxx xxxx uuuu uuuu CCPR1H Capture/Compare/PWM Register1 (MSB) xxxx xxxx uuuu uuuu CCP1CON — — DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000 CCPR2L Capture/Compare/PWM Register2 (LSB) xxxx xxxx uuuu uuuu CCPR2H Capture/Compare/PWM Register2 (MSB) xxxx xxxx uuuu uuuu CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000 Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PWM and Timer2. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.PIC18FXX2 DS39564C-page 124 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 125 PIC18FXX2 15.0 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE 15.1 Master SSP (MSSP) Module Overview The Master Synchronous Serial Port (MSSP) module is a serial interface useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D converters, etc. The MSSP module can operate in one of two modes: • Serial Peripheral Interface (SPI) • Inter-Integrated Circuit (I2C) - Full Master mode - Slave mode (with general address call) The I2C interface supports the following modes in hardware: • Master mode • Multi-Master mode • Slave mode 15.2 Control Registers The MSSP module has three associated registers. These include a status register (SSPSTAT) and two control registers (SSPCON1 and SSPCON2). The use of these registers and their individual configuration bits differ significantly, depending on whether the MSSP module is operated in SPI or I2C mode. Additional details are provided under the individual sections. 15.3 SPI Mode The SPI mode allows 8-bits of data to be synchronously transmitted and received, simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: • Serial Data Out (SDO) - RC5/SDO • Serial Data In (SDI) - RC4/SDI/SDA • Serial Clock (SCK) - RC3/SCK/SCL/LVDIN Additionally, a fourth pin may be used when in a Slave mode of operation: • Slave Select (SS) - RA5/SS/AN4 Figure 15-1 shows the block diagram of the MSSP module when operating in SPI mode. FIGURE 15-1: MSSP BLOCK DIAGRAM (SPI MODE) Read Write Internal Data Bus SSPSR reg SSPM3:SSPM0 bit0 shift clock SS Control Enable Edge Select Clock Select TMR2 output Prescaler TOSC 4, 16, 64 2 Edge Select 2 4 Data to TX/RX in SSPSR TRIS bit 2 SMP:CKE RC5/SDO ( ) SSPBUF reg RC4/SDI/SDA RA5/SS/AN4 RC3/SCK/ SCL/LVDINPIC18FXX2 DS39564C-page 126 © 2006 Microchip Technology Inc. 15.3.1 REGISTERS The MSSP module has four registers for SPI mode operation. These are: • MSSP Control Register1 (SSPCON1) • MSSP Status Register (SSPSTAT) • Serial Receive/Transmit Buffer (SSPBUF) • MSSP Shift Register (SSPSR) - Not directly accessible SSPCON1 and SSPSTAT are the control and status registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the SSPSTAT are read only. The upper two bits of the SSPSTAT are read/write. SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. In receive operations, SSPSR and SSPBUF together create a double buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. During transmission, the SSPBUF is not double buffered. A write to SSPBUF will write to both SSPBUF and SSPSR. REGISTER 15-1: SSPSTAT: MSSP STATUS REGISTER (SPI MODE) R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 SMP CKE D/A P S R/W UA BF bit 7 bit 0 bit 7 SMP: Sample bit SPI Master mode: 1 = Input data sampled at end of data output time 0 = Input data sampled at middle of data output time SPI Slave mode: SMP must be cleared when SPI is used in Slave mode bit 6 CKE: SPI Clock Edge Select When CKP = 0: 1 = Data transmitted on rising edge of SCK 0 = Data transmitted on falling edge of SCK When CKP = 1: 1 = Data transmitted on falling edge of SCK 0 = Data transmitted on rising edge of SCK bit 5 D/A: Data/Address bit Used in I2C mode only bit 4 P: STOP bit Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared. bit 3 S: START bit Used in I2C mode only bit 2 R/W: Read/Write bit information Used in I2C mode only bit 1 UA: Update Address Used in I2C mode only bit 0 BF: Buffer Full Status bit (Receive mode only) 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 127 PIC18FXX2 REGISTER 15-2: SSPCON1: MSSP CONTROL REGISTER1 (SPI MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 bit 7 bit 0 bit 7 WCOL: Write Collision Detect bit (Transmit mode only) 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision bit 6 SSPOV: Receive Overflow Indicator bit SPI Slave mode: 1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode.The user must read the SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software). 0 = No overflow Note: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the SSPBUF register. bit 5 SSPEN: Synchronous Serial Port Enable bit 1 = Enables serial port and configures SCK, SDO, SDI, and SS as serial port pins 0 = Disables serial port and configures these pins as I/O port pins Note: When enabled, these pins must be properly configured as input or output. bit 4 CKP: Clock Polarity Select bit 1 = IDLE state for clock is a high level 0 = IDLE state for clock is a low level bit 3-0 SSPM3:SSPM0: Synchronous Serial Port Mode Select bits 0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin 0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled 0011 = SPI Master mode, clock = TMR2 output/2 0010 = SPI Master mode, clock = FOSC/64 0001 = SPI Master mode, clock = FOSC/16 0000 = SPI Master mode, clock = FOSC/4 Note: Bit combinations not specifically listed here are either reserved, or implemented in I 2C mode only. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 128 © 2006 Microchip Technology Inc. 15.3.2 OPERATION When initializing the SPI, several options need to be specified. This is done by programming the appropriate control bits (SSPCON1<5:0>) and SSPSTAT<7:6>. These control bits allow the following to be specified: • Master mode (SCK is the clock output) • Slave mode (SCK is the clock input) • Clock Polarity (IDLE state of SCK) • Data input sample phase (middle or end of data output time) • Clock edge (output data on rising/falling edge of SCK) • Clock Rate (Master mode only) • Slave Select mode (Slave mode only) The MSSP consists of a transmit/receive Shift Register (SSPSR) and a buffer register (SSPBUF). The SSPSR shifts the data in and out of the device, MSb first. The SSPBUF holds the data that was written to the SSPSR, until the received data is ready. Once the 8 bits of data have been received, that byte is moved to the SSPBUF register. Then the buffer full detect bit, BF (SSPSTAT<0>), and the interrupt flag bit, SSPIF, are set. This double buffering of the received data (SSPBUF) allows the next byte to start reception before reading the data that was just received. Any write to the SSPBUF register during transmission/reception of data will be ignored, and the write collision detect bit, WCOL (SSPCON1<7>), will be set. User software must clear the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed successfully. When the application software is expecting to receive valid data, the SSPBUF should be read before the next byte of data to transfer is written to the SSPBUF. Buffer full bit, BF (SSPSTAT<0>), indicates when SSPBUF has been loaded with the received data (transmission is complete). When the SSPBUF is read, the BF bit is cleared. This data may be irrelevant if the SPI is only a transmitter. Generally, the MSSP Interrupt is used to determine when the transmission/reception has completed. The SSPBUF must be read and/or written. If the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. Example 15-1 shows the loading of the SSPBUF (SSPSR) for data transmission. The SSPSR is not directly readable or writable, and can only be accessed by addressing the SSPBUF register. Additionally, the MSSP status register (SSPSTAT) indicates the various status conditions. EXAMPLE 15-1: LOADING THE SSPBUF (SSPSR) REGISTER LOOP BTFSS SSPSTAT, BF ;Has data been received(transmit complete)? BRA LOOP ;No MOVF SSPBUF, W ;WREG reg = contents of SSPBUF MOVWF RXDATA ;Save in user RAM, if data is meaningful MOVF TXDATA, W ;W reg = contents of TXDATA MOVWF SSPBUF ;New data to xmit © 2006 Microchip Technology Inc. DS39564C-page 129 PIC18FXX2 15.3.3 ENABLING SPI I/O To enable the serial port, SSP Enable bit, SSPEN (SSPCON1<5>), must be set. To reset or reconfigure SPI mode, clear the SSPEN bit, re-initialize the SSPCON registers, and then set the SSPEN bit. This configures the SDI, SDO, SCK, and SS pins as serial port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the TRIS register) appropriately programmed. That is: • SDI is automatically controlled by the SPI module • SDO must have TRISC<5> bit cleared • SCK (Master mode) must have TRISC<3> bit cleared • SCK (Slave mode) must have TRISC<3> bit set • SS must have TRISC<4> bit set Any serial port function that is not desired may be overridden by programming the corresponding data direction (TRIS) register to the opposite value. 15.3.4 TYPICAL CONNECTION Figure 15-2 shows a typical connection between two microcontrollers. The master controller (Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both shift registers on their programmed clock edge, and latched on the opposite edge of the clock. Both processors should be programmed to the same Clock Polarity (CKP), then both controllers would send and receive data at the same time. Whether the data is meaningful (or dummy data) depends on the application software. This leads to three scenarios for data transmission: • Master sends data — Slave sends dummy data • Master sends data — Slave sends data • Master sends dummy data — Slave sends data FIGURE 15-2: SPI MASTER/SLAVE CONNECTION Serial Input Buffer (SSPBUF) Shift Register (SSPSR) MSb LSb SDO SDI PROCESSOR 1 SCK SPI Master SSPM3:SSPM0 = 00xxb Serial Input Buffer (SSPBUF) Shift Register (SSPSR) MSb LSb SDI SDO PROCESSOR 2 SCK SPI Slave SSPM3:SSPM0 = 010xb Serial ClockPIC18FXX2 DS39564C-page 130 © 2006 Microchip Technology Inc. 15.3.5 MASTER MODE The master can initiate the data transfer at any time because it controls the SCK. The master determines when the slave (Processor 2, Figure 15-2) is to broadcast data by the software protocol. In Master mode, the data is transmitted/received as soon as the SSPBUF register is written to. If the SPI is only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register will continue to shift in the signal present on the SDI pin at the programmed clock rate. As each byte is received, it will be loaded into the SSPBUF register as if a normal received byte (interrupts and status bits appropriately set). This could be useful in receiver applications as a “Line Activity Monitor” mode. The clock polarity is selected by appropriately programming the CKP bit (SSPCON1<4>). This then, would give waveforms for SPI communication as shown in Figure 15-3, Figure 15-5, and Figure 15-6, where the MSB is transmitted first. In Master mode, the SPI clock rate (bit rate) is user programmable to be one of the following: • FOSC/4 (or TCY) • FOSC/16 (or 4 • TCY) • FOSC/64 (or 16 • TCY) • Timer2 output/2 This allows a maximum data rate (at 40 MHz) of 10.00 Mbps. Figure 15-3 shows the waveforms for Master mode. When the CKE bit is set, the SDO data is valid before there is a clock edge on SCK. The change of the input sample is shown based on the state of the SMP bit. The time when the SSPBUF is loaded with the received data is shown. FIGURE 15-3: SPI MODE WAVEFORM (MASTER MODE) SCK (CKP = 0 SCK (CKP = 1 SCK (CKP = 0 SCK (CKP = 1 4 Clock Modes Input Sample Input Sample SDI bit7 bit0 SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit7 bit0 SDI SSPIF (SMP = 1) (SMP = 0) (SMP = 1) CKE = 1) CKE = 0) CKE = 1) CKE = 0) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 (CKE = 0) (CKE = 1) Next Q4 cycle after Q2↓© 2006 Microchip Technology Inc. DS39564C-page 131 PIC18FXX2 15.3.6 SLAVE MODE In Slave mode, the data is transmitted and received as the external clock pulses appear on SCK. When the last bit is latched, the SSPIF interrupt flag bit is set. While in Slave mode, the external clock is supplied by the external clock source on the SCK pin. This external clock must meet the minimum high and low times as specified in the electrical specifications. While in SLEEP mode, the slave can transmit/receive data. When a byte is received, the device will wake-up from sleep. 15.3.7 SLAVE SELECT SYNCHRONIZATION The SS pin allows a Synchronous Slave mode. The SPI must be in Slave mode with SS pin control enabled (SSPCON1<3:0> = 04h). The pin must not be driven low for the SS pin to function as an input. The Data Latch must be high. When the SS pin is low, transmission and reception are enabled and the SDO pin is driven. When the SS pin goes high, the SDO pin is no longer driven, even if in the middle of a transmitted byte, and becomes a floating output. External pull-up/ pull-down resistors may be desirable, depending on the application. When the SPI module resets, the bit counter is forced to 0. This can be done by either forcing the SS pin to a high level or clearing the SSPEN bit. To emulate two-wire communication, the SDO pin can be connected to the SDI pin. When the SPI needs to operate as a receiver the SDO pin can be configured as an input. This disables transmissions from the SDO. The SDI can always be left as an input (SDI function), since it cannot create a bus conflict. FIGURE 15-4: SLAVE SYNCHRONIZATION WAVEFORM Note 1: When the SPI is in Slave mode with SS pin control enabled (SSPCON<3:0> = 0100), the SPI module will reset if the SS pin is set to VDD. 2: If the SPI is used in Slave mode with CKE set, then the SS pin control must be enabled. SCK (CKP = 1 SCK (CKP = 0 Input Sample SDI bit7 SDO bit7 bit6 bit7 SSPIF Interrupt (SMP = 0) CKE = 0) CKE = 0) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SS Flag bit0 bit7 bit0 Next Q4 cycle after Q2↓PIC18FXX2 DS39564C-page 132 © 2006 Microchip Technology Inc. FIGURE 15-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0) FIGURE 15-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1) SCK (CKP = 1 SCK (CKP = 0 Input Sample SDI bit7 bit0 SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 SSPIF Interrupt (SMP = 0) CKE = 0) CKE = 0) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SS Flag Optional Next Q4 cycle after Q2↓ SCK (CKP = 1 SCK (CKP = 0 Input Sample SDI bit7 bit0 SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 SSPIF Interrupt (SMP = 0) CKE = 1) CKE = 1) (SMP = 0) Write to SSPBUF SSPSR to SSPBUF SS Flag Not Optional Next Q4 cycle after Q2↓© 2006 Microchip Technology Inc. DS39564C-page 133 PIC18FXX2 15.3.8 SLEEP OPERATION In Master mode, all module clocks are halted and the transmission/reception will remain in that state until the device wakes from SLEEP. After the device returns to Normal mode, the module will continue to transmit/ receive data. In Slave mode, the SPI transmit/receive shift register operates asynchronously to the device. This allows the device to be placed in SLEEP mode and data to be shifted into the SPI transmit/receive shift register. When all 8 bits have been received, the MSSP interrupt flag bit will be set and if enabled, will wake the device from SLEEP. 15.3.9 EFFECTS OF A RESET A RESET disables the MSSP module and terminates the current transfer. 15.3.10 BUS MODE COMPATIBILITY Table 15-1 shows the compatibility between the standard SPI modes and the states the CKP and CKE control bits. TABLE 15-1: SPI BUS MODES There is also a SMP bit which controls when the data is sampled. TABLE 15-2: REGISTERS ASSOCIATED WITH SPI OPERATION Standard SPI Mode Terminology Control Bits State CKP CKE 0, 0 0 1 0, 1 0 0 1, 0 1 1 1, 1 1 0 Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 TRISC PORTC Data Direction Register 1111 1111 1111 1111 SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register xxxx xxxx uuuu uuuu SSPCON WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 0000 0000 TRISA — PORTA Data Direction Register -111 1111 -111 1111 SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 0000 0000 Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the MSSP in SPI mode. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18C2X2 devices; always maintain these bits clear.PIC18FXX2 DS39564C-page 134 © 2006 Microchip Technology Inc. 15.4 I2C Mode The MSSP module in I2C mode fully implements all master and slave functions (including general call support) and provides interrupts on START and STOP bits in hardware to determine a free bus (multi-master function). The MSSP module implements the Standard mode specifications, as well as 7-bit and 10-bit addressing. Two pins are used for data transfer: • Serial clock (SCL) - RC3/SCK/SCL • Serial data (SDA) - RC4/SDI/SDA The user must configure these pins as inputs or outputs through the TRISC<4:3> bits. FIGURE 15-7: MSSP BLOCK DIAGRAM (I2C MODE) 15.4.1 REGISTERS The MSSP module has six registers for I2C operation. These are: • MSSP Control Register1 (SSPCON1) • MSSP Control Register2 (SSPCON2) • MSSP Status Register (SSPSTAT) • Serial Receive/Transmit Buffer (SSPBUF) • MSSP Shift Register (SSPSR) - Not directly accessible • MSSP Address Register (SSPADD) SSPCON, SSPCON2 and SSPSTAT are the control and status registers in I2C mode operation. The SSPCON and SSPCON2 registers are readable and writable. The lower 6 bits of the SSPSTAT are read only. The upper two bits of the SSPSTAT are read/ write. SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. SSPADD register holds the slave device address when the SSP is configured in I2C Slave mode. When the SSP is configured in Master mode, the lower seven bits of SSPADD act as the baud rate generator reload value. In receive operations, SSPSR and SSPBUF together, create a double buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. During transmission, the SSPBUF is not double buffered. A write to SSPBUF will write to both SSPBUF and SSPSR. Read Write SSPSR reg Match Detect SSPADD reg START and STOP bit Detect SSPBUF reg Internal Data Bus Addr Match Set, Reset S, P bits (SSPSTAT reg) RC3/SCK/SCL RC4/ Shift Clock MSb SDI/ LSb SDA© 2006 Microchip Technology Inc. DS39564C-page 135 PIC18FXX2 REGISTER 15-3: SSPSTAT: MSSP STATUS REGISTER (I2C MODE) R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 SMP CKE D/A P S R/W UA BF bit 7 bit 0 bit 7 SMP: Slew Rate Control bit In Master or Slave mode: 1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz) 0 = Slew rate control enabled for High Speed mode (400 kHz) bit 6 CKE: SMBus Select bit In Master or Slave mode: 1 = Enable SMBus specific inputs 0 = Disable SMBus specific inputs bit 5 D/A: Data/Address bit In Master mode: Reserved In Slave mode: 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address bit 4 P: STOP bit 1 = Indicates that a STOP bit has been detected last 0 = STOP bit was not detected last Note: This bit is cleared on RESET and when SSPEN is cleared. bit 3 S: START bit 1 = Indicates that a start bit has been detected last 0 = START bit was not detected last Note: This bit is cleared on RESET and when SSPEN is cleared. bit 2 R/W: Read/Write bit Information (I2C mode only) In Slave mode: 1 = Read 0 = Write Note: This bit holds the R/W bit information following the last address match. This bit is only valid from the address match to the next START bit, STOP bit, or not ACK bit. In Master mode: 1 = Transmit is in progress 0 = Transmit is not in progress Note: ORing this bit with SEN, RSEN, PEN, RCEN, or ACKEN will indicate if the MSSP is in IDLE mode. bit 1 UA: Update Address (10-bit Slave mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated bit 0 BF: Buffer Full Status bit In Transmit mode: 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty In Receive mode: 1 = Data transmit in progress (does not include the ACK and STOP bits), SSPBUF is full 0 = Data transmit complete (does not include the ACK and STOP bits), SSPBUF is empty Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 136 © 2006 Microchip Technology Inc. REGISTER 15-4: SSPCON1: MSSP CONTROL REGISTER1 (I2C MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 bit 7 bit 0 bit 7 WCOL: Write Collision Detect bit In Master Transmit mode: 1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for a transmission to be started (must be cleared in software) 0 = No collision In Slave Transmit mode: 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision In Receive mode (Master or Slave modes): This is a “don’t care” bit bit 6 SSPOV: Receive Overflow Indicator bit In Receive mode: 1 = A byte is received while the SSPBUF register is still holding the previous byte (must be cleared in software) 0 = No overflow In Transmit mode: This is a “don’t care” bit in Transmit mode bit 5 SSPEN: Synchronous Serial Port Enable bit 1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins 0 = Disables serial port and configures these pins as I/O port pins Note: When enabled, the SDA and SCL pins must be properly configured as input or output. bit 4 CKP: SCK Release Control bit In Slave mode: 1 = Release clock 0 = Holds clock low (clock stretch), used to ensure data setup time In Master mode: Unused in this mode bit 3-0 SSPM3:SSPM0: Synchronous Serial Port Mode Select bits 1111 = I2C Slave mode, 10-bit address with START and STOP bit interrupts enabled 1110 = I2C Slave mode, 7-bit address with START and STOP bit interrupts enabled 1011 = I2C Firmware Controlled Master mode (Slave IDLE) 1000 = I2C Master mode, clock = FOSC / (4 * (SSPADD+1)) 0111 = I2C Slave mode, 10-bit address 0110 = I2C Slave mode, 7-bit address Note: Bit combinations not specifically listed here are either reserved, or implemented in SPI mode only. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 137 PIC18FXX2 REGISTER 15-5: SSPCON2: MSSP CONTROL REGISTER 2 (I2C MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN bit 7 bit 0 bit 7 GCEN: General Call Enable bit (Slave mode only) 1 = Enable interrupt when a general call address (0000h) is received in the SSPSR 0 = General call address disabled bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only) 1 = Acknowledge was not received from slave 0 = Acknowledge was received from slave bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only) 1 = Not Acknowledge 0 = Acknowledge Note: Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive. bit 4 ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only) 1 = Initiate Acknowledge sequence on SDA and SCL pins, and transmit ACKDT data bit. Automatically cleared by hardware. 0 = Acknowledge sequence IDLE bit 3 RCEN: Receive Enable bit (Master mode only) 1 = Enables Receive mode for I2C 0 = Receive IDLE bit 2 PEN: STOP Condition Enable bit (Master mode only) 1 = Initiate STOP condition on SDA and SCL pins. Automatically cleared by hardware. 0 = STOP condition IDLE bit 1 RSEN: Repeated START Condition Enabled bit (Master mode only) 1 = Initiate Repeated START condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated START condition IDLE bit 0 SEN: START Condition Enabled/Stretch Enabled bit In Master mode: 1 = Initiate START condition on SDA and SCL pins. Automatically cleared by hardware. 0 = START condition IDLE In Slave mode: 1 = Clock stretching is enabled for both Slave Transmit and Slave Receive (stretch enabled) 0 = Clock stretching is enabled for slave transmit only (Legacy mode) Note: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled). Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 138 © 2006 Microchip Technology Inc. 15.4.2 OPERATION The MSSP module functions are enabled by setting MSSP Enable bit, SSPEN (SSPCON<5>). The SSPCON1 register allows control of the I2C operation. Four mode selection bits (SSPCON<3:0>) allow one of the following I2C modes to be selected: • I2C Master mode, clock = OSC/4 (SSPADD +1) • I2C Slave mode (7-bit address) • I2C Slave mode (10-bit address) • I2C Slave mode (7-bit address), with START and STOP bit interrupts enabled • I2C Slave mode (10-bit address), with START and STOP bit interrupts enabled • I2C Firmware controlled master operation, slave is IDLE Selection of any I2C mode, with the SSPEN bit set, forces the SCL and SDA pins to be open drain, provided these pins are programmed to inputs by setting the appropriate TRISC bits. To guarantee proper operation of the module, pull-up resistors must be provided externally to the SCL and SDA pins. 15.4.3 SLAVE MODE In Slave mode, the SCL and SDA pins must be configured as inputs (TRISC<4:3> set). The MSSP module will override the input state with the output data when required (slave-transmitter). The I2C Slave mode hardware will always generate an interrupt on an address match. Through the mode select bits, the user can also choose to interrupt on START and STOP bits When an address is matched or the data transfer after an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse and load the SSPBUF register with the received value currently in the SSPSR register. Any combination of the following conditions will cause the MSSP module not to give this ACK pulse: • The buffer full bit BF (SSPSTAT<0>) was set before the transfer was received. • The overflow bit SSPOV (SSPCON<6>) was set before the transfer was received. In this case, the SSPSR register value is not loaded into the SSPBUF, but bit SSPIF (PIR1<3>) is set. The BF bit is cleared by reading the SSPBUF register, while bit SSPOV is cleared through software. The SCL clock input must have a minimum high and low for proper operation. The high and low times of the I 2C specification, as well as the requirement of the MSSP module, are shown in timing parameter 100 and parameter 101. 15.4.3.1 Addressing Once the MSSP module has been enabled, it waits for a START condition to occur. Following the START condition, the 8-bits are shifted into the SSPSR register. All incoming bits are sampled with the rising edge of the clock (SCL) line. The value of register SSPSR<7:1> is compared to the value of the SSPADD register. The address is compared on the falling edge of the eighth clock (SCL) pulse. If the addresses match, and the BF and SSPOV bits are clear, the following events occur: 1. The SSPSR register value is loaded into the SSPBUF register. 2. The buffer full bit BF is set. 3. An ACK pulse is generated. 4. MSSP interrupt flag bit, SSPIF (PIR1<3>) is set (interrupt is generated if enabled) on the falling edge of the ninth SCL pulse. In 10-bit Address mode, two address bytes need to be received by the slave. The five Most Significant bits (MSbs) of the first address byte specify if this is a 10-bit address. Bit R/W (SSPSTAT<2>) must specify a write so the slave device will receive the second address byte. For a 10-bit address, the first byte would equal ‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the two MSbs of the address. The sequence of events for 10-bit address is as follows, with steps 7 through 9 for the slave-transmitter: 1. Receive first (high) byte of Address (bits SSPIF, BF and bit UA (SSPSTAT<1>) are set). 2. Update the SSPADD register with second (low) byte of Address (clears bit UA and releases the SCL line). 3. Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. 4. Receive second (low) byte of Address (bits SSPIF, BF, and UA are set). 5. Update the SSPADD register with the first (high) byte of Address. If match releases SCL line, this will clear bit UA. 6. Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. 7. Receive Repeated START condition. 8. Receive first (high) byte of Address (bits SSPIF and BF are set). 9. Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF.© 2006 Microchip Technology Inc. DS39564C-page 139 PIC18FXX2 15.4.3.2 Reception When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into the SSPBUF register and the SDA line is held low (ACK). When the address byte overflow condition exists, then the no Acknowledge (ACK) pulse is given. An overflow condition is defined as either bit BF (SSPSTAT<0>) is set, or bit SSPOV (SSPCON1<6>) is set. An MSSP interrupt is generated for each data transfer byte. Flag bit SSPIF (PIR1<3>) must be cleared in software. The SSPSTAT register is used to determine the status of the byte. If SEN is enabled (SSPCON1<0>=1), RC3/SCK/SCL will be held low (clock stretch) following each data transfer. The clock must be released by setting bit CKP (SSPCON<4>). See Section 15.4.4 (“Clock Stretching”), for more detail. 15.4.3.3 Transmission When the R/W bit of the incoming address byte is set and an address match occurs, the R/W bit of the SSPSTAT register is set. The received address is loaded into the SSPBUF register. The ACK pulse will be sent on the ninth bit and pin RC3/SCK/SCL is held low, regardless of SEN (see “Clock Stretching”, Section 15.4.4, for more detail). By stretching the clock, the master will be unable to assert another clock pulse until the slave is done preparing the transmit data.The transmit data must be loaded into the SSPBUF register, which also loads the SSPSR register. Then pin RC3/ SCK/SCL should be enabled by setting bit CKP (SSPCON1<4>). The eight data bits are shifted out on the falling edge of the SCL input. This ensures that the SDA signal is valid during the SCL high time (Figure 15-9). The ACK pulse from the master-receiver is latched on the rising edge of the ninth SCL input pulse. If the SDA line is high (not ACK), then the data transfer is complete. In this case, when the ACK is latched by the slave, the slave logic is reset (resets SSPSTAT register) and the slave monitors for another occurrence of the START bit. If the SDA line was low (ACK), the next transmit data must be loaded into the SSPBUF register. Again, pin RC3/SCK/SCL must be enabled by setting bit CKP. An MSSP interrupt is generated for each data transfer byte. The SSPIF bit must be cleared in software and the SSPSTAT register is used to determine the status of the byte. The SSPIF bit is set on the falling edge of the ninth clock pulse.PIC18FXX2 DS39564C-page 140 © 2006 Microchip Technology Inc. FIGURE 15-8: I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS) SDA SCL SSPIF BF (SSPSTAT<0>) SSPOV (SSPCON<6>) S 1 2 34 56 7 8 91 234 5 67 89 1 23 45 7 89 P A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0 ACK Receiving Data ACK Receiving Data R/W = 0 ACK Receiving Address Cleared in software SSPBUF is read Bus Master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. D2 6 (PIR1<3>) CKP (CKP does not reset to ‘0’ when SEN = 0)© 2006 Microchip Technology Inc. DS39564C-page 141 PIC18FXX2 FIGURE 15-9: I2C SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS) SDA SCL SSPIF (PIR1<3>) BF (SSPSTAT<0>) A6 A5 A4 A3 A2 A1 D6 D5 D4 D3 D2 D1 D0 1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9 SSPBUF is written in software Cleared in software SCL held low while CPU responds to SSPIF From SSPIF ISR Data in sampled S ACK Transmitting Data R/W = 1 ACK Receiving Address A7 D7 9 1 D6 D5 D4 D3 D2 D1 D0 2 3 4 5 6 7 8 9 SSPBUF is written in software Cleared in software From SSPIF ISR Transmitting Data D7 1 CKP P ACK CKP is set in software CKP is set in softwarePIC18FXX2 DS39564C-page 142 © 2006 Microchip Technology Inc. FIGURE 15-10: I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS) SDA SCL SSPIF BF (SSPSTAT<0>) S 1 234 56 7 89 1 2345 67 89 1 2345 7 89 P 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D1 D0 Receive Data Byte ACK R/W = 0 ACK Receive First Byte of Address Cleared in software D2 6 (PIR1<3>) Cleared in software Receive Second Byte of Address Cleared by hardware when SSPADD is updated with low byte of address UA (SSPSTAT<1>) Clock is held low until update of SSPADD has taken place UA is set indicating that the SSPADD needs to be updated UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag ACK CKP D7 D6 D5 D4 D3 D1 D0 12345 789 Receive Data Byte Bus Master terminates transfer D2 6 ACK Cleared in software Cleared in software SSPOV (SSPCON<6>) SSPOV is set because SSPBUF is still full. ACK is not sent. (CKP does not reset to ‘0’ when SEN = 0) Clock is held low until update of SSPADD has taken place© 2006 Microchip Technology Inc. DS39564C-page 143 PIC18FXX2 FIGURE 15-11: I2C SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS) SDA SCL SSPIF BF (SSPSTAT<0>) S 1 234 56 789 1 2345 67 89 1 2345 789 P 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 1 1 1 1 0 A8 R/W=1 ACK ACK R/W = 0 ACK Receive First Byte of Address Cleared in software Bus Master terminates transfer A9 6 (PIR1<3>) Receive Second Byte of Address Cleared by hardware when SSPADD is updated with low byte of address UA (SSPSTAT<1>) Clock is held low until update of SSPADD has taken place UA is set indicating that the SSPADD needs to be updated UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address. SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag Receive First Byte of Address D7 D6 D5 D4 D3 D1 12345 789 ACK D2 6 Transmitting Data Byte D0 Dummy read of SSPBUF to clear BF flag Sr Cleared in software Write of SSPBUF initiates transmit Cleared in software Completion of clears BF flag CKP (SSPCON<4>) CKP is set in software CKP is automatically cleared in hardware holding SCL low Clock is held low until update of SSPADD has taken place data transmission Clock is held low until CKP is set to ‘1’ BF flag is clear at the end of the third address sequencePIC18FXX2 DS39564C-page 144 © 2006 Microchip Technology Inc. 15.4.4 CLOCK STRETCHING Both 7- and 10-bit Slave modes implement automatic clock stretching during a transmit sequence. The SEN bit (SSPCON2<0>) allows clock stretching to be enabled during receives. Setting SEN will cause the SCL pin to be held low at the end of each data receive sequence. 15.4.4.1 Clock Stretching for 7-bit Slave Receive Mode (SEN = 1) In 7-bit Slave Receive mode, on the falling edge of the ninth clock at the end of the ACK sequence, if the BF bit is set, the CKP bit in the SSPCON1 register is automatically cleared, forcing the SCL output to be held low. The CKP being cleared to ‘0’ will assert the SCL line low. The CKP bit must be set in the user’s ISR before reception is allowed to continue. By holding the SCL line low, the user has time to service the ISR and read the contents of the SSPBUF before the master device can initiate another receive sequence. This will prevent buffer overruns from occurring (see Figure 15-13). 15.4.4.2 Clock Stretching for 10-bit Slave Receive Mode (SEN = 1) In 10-bit Slave Receive mode, during the address sequence, clock stretching automatically takes place but CKP is not cleared. During this time, if the UA bit is set after the ninth clock, clock stretching is initiated. The UA bit is set after receiving the upper byte of the 10-bit address, and following the receive of the second byte of the 10-bit address with the R/W bit cleared to ‘0’. The release of the clock line occurs upon updating SSPADD. Clock stretching will occur on each data receive sequence as described in 7-bit mode. 15.4.4.3 Clock Stretching for 7-bit Slave Transmit Mode 7-bit Slave Transmit mode implements clock stretching by clearing the CKP bit after the falling edge of the ninth clock, if the BF bit is clear. This occurs, regardless of the state of the SEN bit. The user’s ISR must set the CKP bit before transmission is allowed to continue. By holding the SCL line low, the user has time to service the ISR and load the contents of the SSPBUF before the master device can initiate another transmit sequence (see Figure 15-9). 15.4.4.4 Clock Stretching for 10-bit Slave Transmit Mode In 10-bit Slave Transmit mode, clock stretching is controlled during the first two address sequences by the state of the UA bit, just as it is in 10-bit Slave Receive mode. The first two addresses are followed by a third address sequence, which contains the high order bits of the 10-bit address and the R/W bit set to ‘1’. After the third address sequence is performed, the UA bit is not set, the module is now configured in Transmit mode, and clock stretching is controlled by the BF flag, as in 7-bit Slave Transmit mode (see Figure 15-11). Note 1: If the user reads the contents of the SSPBUF before the falling edge of the ninth clock, thus clearing the BF bit, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software, regardless of the state of the BF bit. The user should be careful to clear the BF bit in the ISR before the next receive sequence, in order to prevent an overflow condition. Note: If the user polls the UA bit and clears it by updating the SSPADD register before the falling edge of the ninth clock occurs, and if the user hasn’t cleared the BF bit by reading the SSPBUF register before that time, then the CKP bit will still NOT be asserted low. Clock stretching on the basis of the state of the BF bit only occurs during a data sequence, not an address sequence. Note 1: If the user loads the contents of SSPBUF, setting the BF bit before the falling edge of the ninth clock, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software, regardless of the state of the BF bit.© 2006 Microchip Technology Inc. DS39564C-page 145 PIC18FXX2 15.4.4.5 Clock Synchronization and the CKP bit If a user clears the CKP bit, the SCL output is forced to ‘0’. Setting the CKP bit will not assert the SCL output low until the SCL output is already sampled low. If the user attempts to drive SCL low, the CKP bit will not assert the SCL line until an external I2C master device has already asserted the SCL line. The SCL output will remain low until the CKP bit is set, and all other devices on the I2C bus have de-asserted SCL. This ensures that a write to the CKP bit will not violate the minimum high time requirement for SCL (see Figure 15-12). FIGURE 15-12: CLOCK SYNCHRONIZATION TIMING SDA SCL DX DX-1 WR Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 SSPCON CKP Master device de-asserts clock Master device asserts clockPIC18FXX2 DS39564C-page 146 © 2006 Microchip Technology Inc. FIGURE 15-13: I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS) SDA SCL SSPIF BF (SSPSTAT<0>) SSPOV (SSPCON<6>) S 1 2 34 56 7 8 9 1 234 5 67 89 1 23 45 7 89 P A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0 ACK Receiving Data ACK Receiving Data R/W = 0 ACK Receiving Address Cleared in software SSPBUF is read Bus Master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. D2 6 (PIR1<3>) CKP CKP written to ‘1’ in If BF is cleared prior to the falling edge of the 9th clock, CKP will not be reset to ‘0’ and no clock stretching will occur software Clock is held low until CKP is set to ‘1’ Clock is not held low because buffer full bit is clear prior to falling edge of 9th clock Clock is not held low because ACK = 1 BF is set after falling edge of the 9th clock, CKP is reset to ‘0’ and clock stretching occurs© 2006 Microchip Technology Inc. DS39564C-page 147 PIC18FXX2 FIGURE 15-14: I2C SLAVE MODE TIMING SEN = 1 (RECEPTION, 10-BIT ADDRESS) SDA SCL SSPIF BF (SSPSTAT<0>) S 1 234 56 7 8 9 1 234 5 67 89 1 2345 7 89 P 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D1 D0 Receive Data Byte ACK R/W = 0 ACK Receive First Byte of Address Cleared in software D2 6 (PIR1<3>) Cleared in software Receive Second Byte of Address Cleared by hardware when SSPADD is updated with low byte of address after falling edge UA (SSPSTAT<1>) Clock is held low until update of SSPADD has taken place UA is set indicating that the SSPADD needs to be updated UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address after falling edge SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag ACK CKP D7 D6 D5 D4 D3 D1 D0 12345 789 Receive Data Byte Bus Master terminates transfer D2 6 ACK Cleared in software Cleared in software SSPOV (SSPCON<6>) CKP written to ‘1’ Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA, and UA will remain set. Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA, and UA will remain set. in software Clock is held low until update of SSPADD has taken place of ninth clock. of ninth clock. SSPOV is set because SSPBUF is still full. ACK is not sent. Dummy read of SSPBUF to clear BF flag Clock is held low until CKP is set to ‘1’ Clock is not held low because ACK = 1PIC18FXX2 DS39564C-page 148 © 2006 Microchip Technology Inc. 15.4.5 GENERAL CALL ADDRESS SUPPORT The addressing procedure for the I2C bus is such that the first byte after the START condition usually determines which device will be the slave addressed by the master. The exception is the general call address, which can address all devices. When this address is used, all devices should, in theory, respond with an Acknowledge. The general call address is one of eight addresses reserved for specific purposes by the I2C protocol. It consists of all 0’s with R/W = 0. The general call address is recognized when the General Call Enable bit (GCEN) is enabled (SSPCON2<7> set). Following a START bit detect, 8-bits are shifted into the SSPSR and the address is compared against the SSPADD. It is also compared to the general call address and fixed in hardware. If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag bit is set (eighth bit), and on the falling edge of the ninth bit (ACK bit), the SSPIF interrupt flag bit is set. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF. The value can be used to determine if the address was device specific or a general call address. In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match, and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when the GCEN bit is set, while the slave is configured in 10-bit Address mode, then the second half of the address is not necessary, the UA bit will not be set, and the slave will begin receiving data after the Acknowledge (Figure 15-15). FIGURE 15-15: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT ADDRESS MODE) SDA SCL S SSPIF BF (SSPSTAT<0>) SSPOV (SSPCON1<6>) Cleared in software SSPBUF is read R/W = 0 ACK General Call Address Address is compared to General Call Address GCEN (SSPCON2<7>) Receiving data ACK 1 2 34 56 7891 2 34 56 789 D7 D6 D5 D4 D3 D2 D1 D0 after ACK, set interrupt '0' '1'© 2006 Microchip Technology Inc. DS39564C-page 149 PIC18FXX2 15.4.6 MASTER MODE Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware. Master mode of operation is supported by interrupt generation on the detection of the START and STOP conditions. The STOP (P) and START (S) bits are cleared from a RESET or when the MSSP module is disabled. Control of the I2C bus may be taken when the P bit is set or the bus is IDLE, with both the S and P bits clear. In Firmware Controlled Master mode, user code conducts all I2C bus operations based on START and STOP bit conditions. Once Master mode is enabled, the user has six options. 1. Assert a START condition on SDA and SCL. 2. Assert a Repeated START condition on SDA and SCL. 3. Write to the SSPBUF register initiating transmission of data/address. 4. Configure the I2C port to receive data. 5. Generate an Acknowledge condition at the end of a received byte of data. 6. Generate a STOP condition on SDA and SCL. The following events will cause SSP interrupt flag bit, SSPIF, to be set (SSP interrupt if enabled): • START condition • STOP condition • Data transfer byte transmitted/received • Acknowledge Transmit • Repeated START FIGURE 15-16: MSSP BLOCK DIAGRAM (I2C MASTER MODE) Note: The MSSP Module, when configured in I2C Master mode, does not allow queueing of events. For instance, the user is not allowed to initiate a START condition and immediately write the SSPBUF register to initiate transmission before the START condition is complete. In this case, the SSPBUF will not be written to and the WCOL bit will be set, indicating that a write to the SSPBUF did not occur. Read Write SSPSR START bit, STOP bit, START bit Detect SSPBUF Internal Data Bus Set/Reset, S, P, WCOL (SSPSTAT) Shift Clock MSb LSb SDA Acknowledge Generate STOP bit Detect Write Collision Detect Clock Arbitration State Counter for end of XMIT/RCV SCL SCL in Bus Collision SDA in Receive Enable Clock Cntl Clock Arbitrate/WCOL Detect (hold off clock source) SSPADD<6:0> Baud Set SSPIF, BCLIF Reset ACKSTAT, PEN (SSPCON2) Rate Generator SSPM3:SSPM0PIC18FXX2 DS39564C-page 150 © 2006 Microchip Technology Inc. 15.4.6.1 I2C Master Mode Operation The master device generates all of the serial clock pulses and the START and STOP conditions. A transfer is ended with a STOP condition or with a Repeated START condition. Since the Repeated START condition is also the beginning of the next serial transfer, the I 2C bus will not be released. In Master Transmitter mode, serial data is output through SDA, while SCL outputs the serial clock. The first byte transmitted contains the slave address of the receiving device (7 bits) and the Read/Write (R/W) bit. In this case, the R/W bit will be logic '0'. Serial data is transmitted 8 bits at a time. After each byte is transmitted, an Acknowledge bit is received. START and STOP conditions are output to indicate the beginning and the end of a serial transfer. In Master Receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the R/W bit. In this case, the R/W bit will be logic '1'. Thus, the first byte transmitted is a 7-bit slave address followed by a '1' to indicate receive bit. Serial data is received via SDA, while SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an Acknowledge bit is transmitted. START and STOP conditions indicate the beginning and end of transmission. The baud rate generator used for the SPI mode operation is used to set the SCL clock frequency for either 100 kHz, 400 kHz or 1 MHz I2C operation. See Section 15.4.7 (“Baud Rate Generator”), for more detail. A typical transmit sequence would go as follows: 1. The user generates a START condition by setting the START enable bit, SEN (SSPCON2<0>). 2. SSPIF is set. The MSSP module will wait the required start time before any other operation takes place. 3. The user loads the SSPBUF with the slave address to transmit. 4. Address is shifted out the SDA pin until all 8 bits are transmitted. 5. The MSSP Module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 6. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 7. The user loads the SSPBUF with eight bits of data. 8. Data is shifted out the SDA pin until all 8 bits are transmitted. 9. The MSSP Module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 10. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 11. The user generates a STOP condition by setting the STOP enable bit PEN (SSPCON2<2>). 12. Interrupt is generated once the STOP condition is complete.© 2006 Microchip Technology Inc. DS39564C-page 151 PIC18FXX2 15.4.7 BAUD RATE GENERATOR In I2C Master mode, the baud rate generator (BRG) reload value is placed in the lower 7 bits of the SSPADD register (Figure 15-17). When a write occurs to SSPBUF, the baud rate generator will automatically begin counting. The BRG counts down to 0 and stops until another reload has taken place. The BRG count is decremented twice per instruction cycle (TCY) on the Q2 and Q4 clocks. In I2C Master mode, the BRG is reloaded automatically. Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal clock will automatically stop counting and the SCL pin will remain in its last state. Table 15-3 demonstrates clock rates based on instruction cycles and the BRG value loaded into SSPADD. FIGURE 15-17: BAUD RATE GENERATOR BLOCK DIAGRAM TABLE 15-3: I2C CLOCK RATE W/BRG SSPM3:SSPM0 CLKO BRG Down Counter Fosc/4 SSPADD<6:0> SSPM3:SSPM0 SCL Reload Control Reload FCY FCY*2 BRG Value FSCL(2) (2 Rollovers of BRG) 10 MHz 20 MHz 19h 400 kHz(1) 10 MHz 20 MHz 20h 312.5 kHz 10 MHz 20 MHz 3Fh 100 kHz 4 MHz 8 MHz 0Ah 400 kHz(1) 4 MHz 8 MHz 0Dh 308 kHz 4 MHz 8 MHz 28h 100 kHz 1 MHz 2 MHz 03h 333 kHz(1) 1 MHz 2 MHz 0Ah 100kHz 1 MHz 2 MHz 00h 1 MHz(1) Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than 100 kHz) in all details, but may be used with care where higher rates are required by the application. 2: Actual frequency will depend on bus conditions. Theoretically, bus conditions will add rise time and extend low time of clock period, producing the effective frequency.PIC18FXX2 DS39564C-page 152 © 2006 Microchip Technology Inc. 15.4.7.1 Clock Arbitration Clock arbitration occurs when the master, during any receive, transmit or Repeated START/STOP condition, de-asserts the SCL pin (SCL allowed to float high). When the SCL pin is allowed to float high, the baud rate generator (BRG) is suspended from counting until the SCL pin is actually sampled high. When the SCL pin is sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. This ensures that the SCL high time will always be at least one BRG rollover count, in the event that the clock is held low by an external device (Figure 15-18). FIGURE 15-18: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION SDA SCL SCL de-asserted but slave holds DX DX-1 BRG SCL is sampled high, reload takes place and BRG starts its count. 03h 02h 01h 00h (hold off) 03h 02h Reload BRG Value SCL low (clock arbitration) SCL allowed to transition high BRG decrements on Q2 and Q4 cycles© 2006 Microchip Technology Inc. DS39564C-page 153 PIC18FXX2 15.4.8 I2C MASTER MODE START CONDITION TIMING To initiate a START condition, the user sets the START condition enable bit, SEN (SSPCON2<0>). If the SDA and SCL pins are sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and starts its count. If SCL and SDA are both sampled high when the baud rate generator times out (TBRG), the SDA pin is driven low. The action of the SDA being driven low, while SCL is high, is the START condition and causes the S bit (SSPSTAT<3>) to be set. Following this, the baud rate generator is reloaded with the contents of SSPADD<6:0> and resumes its count. When the baud rate generator times out (TBRG), the SEN bit (SSPCON2<0>) will be automatically cleared by hardware, the baud rate generator is suspended, leaving the SDA line held low and the START condition is complete. 15.4.8.1 WCOL Status Flag If the user writes the SSPBUF when a START sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 15-19: FIRST START BIT TIMING Note: If at the beginning of the START condition, the SDA and SCL pins are already sampled low, or if during the START condition the SCL line is sampled low before the SDA line is driven low, a bus collision occurs, the Bus Collision Interrupt Flag, BCLIF is set, the START condition is aborted, and the I2C module is reset into its IDLE state. Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the START condition is complete. SDA SCL S TBRG 1st bit 2nd bit TBRG SDA = 1, At completion of START bit, SCL = 1 TBRG Write to SSPBUF occurs here Hardware clears SEN bit TBRG Write to SEN bit occurs here Set S bit (SSPSTAT<3>) and sets SSPIF bitPIC18FXX2 DS39564C-page 154 © 2006 Microchip Technology Inc. 15.4.9 I2C MASTER MODE REPEATED START CONDITION TIMING A Repeated START condition occurs when the RSEN bit (SSPCON2<1>) is programmed high and the I2C logic module is in the IDLE state. When the RSEN bit is set, the SCL pin is asserted low. When the SCL pin is sampled low, the baud rate generator is loaded with the contents of SSPADD<5:0> and begins counting. The SDA pin is released (brought high) for one baud rate generator count (TBRG). When the baud rate generator times out, if SDA is sampled high, the SCL pin will be de-asserted (brought high). When SCL is sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and SCL must be sampled high for one TBRG. This action is then followed by assertion of the SDA pin (SDA = 0) for one TBRG, while SCL is high. Following this, the RSEN bit (SSPCON2<1>) will be automatically cleared and the baud rate generator will not be reloaded, leaving the SDA pin held low. As soon as a START condition is detected on the SDA and SCL pins, the S bit (SSPSTAT<3>) will be set. The SSPIF bit will not be set until the baud rate generator has timed out. Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7-bit mode, or the default first address in 10-bit mode. After the first eight bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode) or eight bits of data (7-bit mode). 15.4.9.1 WCOL Status Flag If the user writes the SSPBUF when a Repeated START sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 15-20: REPEAT START CONDITION WAVEFORM Note 1: If RSEN is programmed while any other event is in progress, it will not take effect. 2: A bus collision during the Repeated START condition occurs if: • SDA is sampled low when SCL goes from low to high. • SCL goes low before SDA is asserted low. This may indicate that another master is attempting to transmit a data "1". Note: Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated START condition is complete. SDA SCL Sr = Repeated START Write to SSPCON2 Falling edge of ninth clock Write to SSPBUF occurs here End of Xmit At completion of START bit, hardware clear RSEN bit 1st bit Set S (SSPSTAT<3>) TBRG TBRG SDA = 1, SDA = 1, SCL (no change) SCL = 1 occurs here. TBRG TBRG TBRG and set SSPIF© 2006 Microchip Technology Inc. DS39564C-page 155 PIC18FXX2 15.4.10 I2C MASTER MODE TRANSMISSION Transmission of a data byte, a 7-bit address, or the other half of a 10-bit address is accomplished by simply writing a value to the SSPBUF register. This action will set the buffer full flag bit, BF, and allow the baud rate generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto the SDA pin after the falling edge of SCL is asserted (see data hold time specification parameter 106). SCL is held low for one baud rate generator rollover count (TBRG). Data should be valid before SCL is released high (see data setup time specification parameter 107). When the SCL pin is released high, it is held that way for TBRG. The data on the SDA pin must remain stable for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the falling edge of the eighth clock), the BF flag is cleared and the master releases SDA. This allows the slave device being addressed to respond with an ACK bit during the ninth bit time if an address match occurred or if data was received properly. The status of ACK is written into the ACKDT bit on the falling edge of the ninth clock. If the master receives an Acknowledge, the Acknowledge status bit, ACKSTAT, is cleared. If not, the bit is set. After the ninth clock, the SSPIF bit is set and the master clock (baud rate generator) is suspended until the next data byte is loaded into the SSPBUF, leaving SCL low and SDA unchanged (Figure 15-21). After the write to the SSPBUF, each bit of address will be shifted out on the falling edge of SCL until all seven address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will de-assert the SDA pin, allowing the slave to respond with an Acknowledge. On the falling edge of the ninth clock, the master will sample the SDA pin to see if the address was recognized by a slave. The status of the ACK bit is loaded into the ACKSTAT status bit (SSPCON2<6>). Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is cleared and the baud rate generator is turned off until another write to the SSPBUF takes place, holding SCL low and allowing SDA to float. 15.4.10.1 BF Status Flag In Transmit mode, the BF bit (SSPSTAT<0>) is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out. 15.4.10.2 WCOL Status Flag If the user writes the SSPBUF when a transmit is already in progress (i.e., SSPSR is still shifting out a data byte), the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). WCOL must be cleared in software. 15.4.10.3 ACKSTAT Status Flag In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is cleared when the slave has sent an Acknowledge (ACK = 0), and is set when the slave does not Acknowledge (ACK = 1). A slave sends an Acknowledge when it has recognized its address (including a general call) or when the slave has properly received its data. 15.4.11 I2C MASTER MODE RECEPTION Master mode reception is enabled by programming the receive enable bit, RCEN (SSPCON2<3>). The baud rate generator begins counting, and on each rollover, the state of the SCL pin changes (high to low/ low to high) and data is shifted into the SSPSR. After the falling edge of the eighth clock, the receive enable flag is automatically cleared, the contents of the SSPSR are loaded into the SSPBUF, the BF flag bit is set, the SSPIF flag bit is set and the baud rate generator is suspended from counting, holding SCL low. The MSSP is now in IDLE state, awaiting the next command. When the buffer is read by the CPU, the BF flag bit is automatically cleared. The user can then send an Acknowledge bit at the end of reception, by setting the Acknowledge sequence enable bit, ACKEN (SSPCON2<4>). 15.4.11.1 BF Status Flag In receive operation, the BF bit is set when an address or data byte is loaded into SSPBUF from SSPSR. It is cleared when the SSPBUF register is read. 15.4.11.2 SSPOV Status Flag In receive operation, the SSPOV bit is set when 8 bits are received into the SSPSR and the BF flag bit is already set from a previous reception. 15.4.11.3 WCOL Status Flag If the user writes the SSPBUF when a receive is already in progress (i.e., SSPSR is still shifting in a data byte), the WCOL bit is set and the contents of the buffer are unchanged (the write doesn’t occur). Note: In the MSSP module, the RCEN bit must be set after the ACK sequence or the RCEN bit will be disregarded. PIC18FXX2 DS39564C-page 156 © 2006 Microchip Technology Inc. FIGURE 15-21: I2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS) SDA SCL SSPIF BF (SSPSTAT<0>) SEN A7 A6 A5 A4 A3 A2 A1 ACK = 0 D7 D6 D5 D4 D3 D2 D1 D0 ACK Transmitting Data or Second Half R/W = 0 Transmit Address to Slave 123456789 123456789 P Cleared in software service routine From SSP interrupt SSPBUF is written in software After START condition, SEN cleared by hardware S SSPBUF written with 7-bit address and R/W start transmit SCL held low while CPU responds to SSPIF SEN = 0 of 10-bit Address Write SSPCON2<0> SEN = 1 START condition begins From slave clear ACKSTAT bit SSPCON2<6> ACKSTAT in SSPCON2 = 1 Cleared in software SSPBUF written PEN Cleared in software R/W© 2006 Microchip Technology Inc. DS39564C-page 157 PIC18FXX2 FIGURE 15-22: I2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS) P 9 8 7 6 5 D0 D1 D2 D3 D4 D5 D6 D7 S A7 A6 A5 A4 A3 A2 A1 SDA SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 678 9 1234 Bus Master terminates transfer ACK Receiving Data from Slave Receiving Data from Slave D0 D1 D2 D3 D4 D5 D6 D7 ACK R/W = 1 Transmit Address to Slave SSPIF BF ACK is not sent Write to SSPCON2<0> (SEN = 1) Write to SSPBUF occurs here ACK from Slave Master configured as a receiver by programming SSPCON2<3>, (RCEN = 1) PEN bit = 1 written here Data shifted in on falling edge of CLK Cleared in software Start XMIT SEN = 0 SDA = 0, SCL = 1 SSPOV while CPU (SSPSTAT<0>) ACK Last bit is shifted into SSPSR and contents are unloaded into SSPBUF Cleared in software Cleared in software Set SSPIF interrupt at end of receive Set P bit (SSPSTAT<4>) and SSPIF Cleared in software ACK from Master Set SSPIF at end Set SSPIF interrupt at end of Acknowledge sequence Set SSPIF interrupt at end of Acknowledge sequence of receive Set ACKEN, start Acknowledge sequence SSPOV is set because SSPBUF is still full SDA = ACKDT = 1 RCEN cleared automatically RCEN = 1 start next receive Write to SSPCON2<4> to start Acknowledge sequence SDA = ACKDT (SSPCON2<5>) = 0 RCEN cleared automatically responds to SSPIF ACKEN Begin START Condition Cleared in software SDA = ACKDT = 0 PIC18FXX2 DS39564C-page 158 © 2006 Microchip Technology Inc. 15.4.12 ACKNOWLEDGE SEQUENCE TIMING An Acknowledge sequence is enabled by setting the Acknowledge sequence enable bit, ACKEN (SSPCON2<4>). When this bit is set, the SCL pin is pulled low and the contents of the Acknowledge data bit are presented on the SDA pin. If the user wishes to generate an Acknowledge, then the ACKDT bit should be cleared. If not, the user should set the ACKDT bit before starting an Acknowledge sequence. The baud rate generator then counts for one rollover period (TBRG) and the SCL pin is de-asserted (pulled high). When the SCL pin is sampled high (clock arbitration), the baud rate generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the baud rate generator is turned off and the MSSP module then goes into IDLE mode (Figure 15-23). 15.4.12.1 WCOL Status Flag If the user writes the SSPBUF when an Acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). 15.4.13 STOP CONDITION TIMING A STOP bit is asserted on the SDA pin at the end of a receive/transmit by setting the STOP sequence enable bit, PEN (SSPCON2<2>). At the end of a receive/transmit the SCL line is held low after the falling edge of the ninth clock. When the PEN bit is set, the master will assert the SDA line low. When the SDA line is sampled low, the baud rate generator is reloaded and counts down to 0. When the baud rate generator times out, the SCL pin will be brought high, and one TBRG (baud rate generator rollover count) later, the SDA pin will be de-asserted. When the SDA pin is sampled high while SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 15-24). 15.4.13.1 WCOL Status Flag If the user writes the SSPBUF when a STOP sequence is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 15-23: ACKNOWLEDGE SEQUENCE WAVEFORM FIGURE 15-24: STOP CONDITION RECEIVE OR TRANSMIT MODE Note: TBRG = one baud rate generator period. SDA SCL Set SSPIF at the end Acknowledge sequence starts here, Write to SSPCON2 ACKEN automatically cleared Cleared in TBRG TBRG of receive ACK 8 ACKEN = 1, ACKDT = 0 D0 9 SSPIF software Set SSPIF at the end of Acknowledge sequence Cleared in software SCL SDA SDA asserted low before rising edge of clock Write to SSPCON2 Set PEN Falling edge of SCL = 1 for TBRG, followed by SDA = 1 for TBRG 9th clock SCL brought high after TBRG Note: TBRG = one baud rate generator period. TBRG TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. TBRG to setup STOP condition. ACK P TBRG PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set© 2006 Microchip Technology Inc. DS39564C-page 159 PIC18FXX2 15.4.14 SLEEP OPERATION While in SLEEP mode, the I2C module can receive addresses or data, and when an address match or complete byte transfer occurs, wake the processor from SLEEP (if the MSSP interrupt is enabled). 15.4.15 EFFECT OF A RESET A RESET disables the MSSP module and terminates the current transfer. 15.4.16 MULTI-MASTER MODE In Multi-Master mode, the interrupt generation on the detection of the START and STOP conditions allows the determination of when the bus is free. The STOP (P) and START (S) bits are cleared from a RESET or when the MSSP module is disabled. Control of the I2C bus may be taken when the P bit (SSPSTAT<4>) is set, or the bus is idle with both the S and P bits clear. When the bus is busy, enabling the SSP interrupt will generate the interrupt when the STOP condition occurs. In multi-master operation, the SDA line must be monitored for arbitration, to see if the signal level is the expected output level. This check is performed in hardware, with the result placed in the BCLIF bit. The states where arbitration can be lost are: • Address Transfer • Data Transfer • A START Condition • A Repeated START Condition • An Acknowledge Condition 15.4.17 MULTI -MASTER COMMUNICATION, BUS COLLISION, AND BUS ARBITRATION Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto the SDA pin, arbitration takes place when the master outputs a '1' on SDA, by letting SDA float high and another master asserts a '0'. When the SCL pin floats high, data should be stable. If the expected data on SDA is a '1' and the data sampled on the SDA pin = '0', then a bus collision has taken place. The master will set the Bus Collision Interrupt Flag BCLIF and reset the I2C port to its IDLE state (Figure 15-25). If a transmit was in progress when the bus collision occurred, the transmission is halted, the BF flag is cleared, the SDA and SCL lines are de-asserted, and the SSPBUF can be written to. When the user services the bus collision Interrupt Service Routine, and if the I 2C bus is free, the user can resume communication by asserting a START condition. If a START, Repeated START, STOP, or Acknowledge condition was in progress when the bus collision occurred, the condition is aborted, the SDA and SCL lines are de-asserted, and the respective control bits in the SSPCON2 register are cleared. When the user services the bus collision Interrupt Service Routine, and if the I2C bus is free, the user can resume communication by asserting a START condition. The master will continue to monitor the SDA and SCL pins. If a STOP condition occurs, the SSPIF bit will be set. A write to the SSPBUF will start the transmission of data at the first data bit, regardless of where the transmitter left off when the bus collision occurred. In Multi-Master mode, the interrupt generation on the detection of START and STOP conditions allows the determination of when the bus is free. Control of the I2C bus can be taken when the P bit is set in the SSPSTAT register, or the bus is IDLE and the S and P bits are cleared. FIGURE 15-25: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE SDA SCL BCLIF SDA released SDA line pulled low by another source Sample SDA. While SCL is high, data doesn’t match what is driven Bus collision has occurred. Set bus collision interrupt (BCLIF) by the master. by master Data changes while SCL = 0PIC18FXX2 DS39564C-page 160 © 2006 Microchip Technology Inc. 15.4.17.1 Bus Collision During a START Condition During a START condition, a bus collision occurs if: a) SDA or SCL are sampled low at the beginning of the START condition (Figure 15-26). b) SCL is sampled low before SDA is asserted low (Figure 15-27). During a START condition, both the SDA and the SCL pins are monitored. If the SDA pin is already low, or the SCL pin is already low, then all of the following occur: • the START condition is aborted, • the BCLIF flag is set, and • the MSSP module is reset to its IDLE state (Figure 15-26). The START condition begins with the SDA and SCL pins de-asserted. When the SDA pin is sampled high, the baud rate generator is loaded from SSPADD<6:0> and counts down to 0. If the SCL pin is sampled low while SDA is high, a bus collision occurs, because it is assumed that another master is attempting to drive a data '1' during the START condition. If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 15-28). If, however, a '1' is sampled on the SDA pin, the SDA pin is asserted low at the end of the BRG count. The baud rate generator is then reloaded and counts down to 0, and during this time, if the SCL pins are sampled as '0', a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. FIGURE 15-26: BUS COLLISION DURING START CONDITION (SDA ONLY) Note: The reason that bus collision is not a factor during a START condition is that no two bus masters can assert a START condition at the exact same time. Therefore, one master will always assert SDA before the other. This condition does not cause a bus collision, because the two masters must be allowed to arbitrate the first address following the START condition. If the address is the same, arbitration must be allowed to continue into the data portion, Repeated START or STOP conditions. SDA SCL SEN SDA sampled low before SDA goes low before the SEN bit is set. S bit and SSPIF set because SSP module reset into IDLE state. SEN cleared automatically because of bus collision. S bit and SSPIF set because Set SEN, enable START condition if SDA = 1, SCL=1 SDA = 0, SCL = 1. BCLIF S SSPIF SDA = 0, SCL = 1. SSPIF and BCLIF are cleared in software. SSPIF and BCLIF are cleared in software. Set BCLIF, START condition. Set BCLIF.© 2006 Microchip Technology Inc. DS39564C-page 161 PIC18FXX2 FIGURE 15-27: BUS COLLISION DURING START CONDITION (SCL = 0) FIGURE 15-28: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION SDA SCL SEN bus collision occurs. set BCLIF SCL = 0 before SDA = 0, Set SEN, enable START sequence if SDA = 1, SCL = 1 TBRG TBRG SDA = 0, SCL = 1 BCLIF S SSPIF Interrupt cleared in software bus collision occurs. Set BCLIF. SCL = 0 before BRG time-out, '0' '0' '0' '0' SDA SCL SEN Set S Set SEN, enable START sequence if SDA = 1, SCL = 1 Less than TBRG TBRG SDA = 0, SCL = 1 BCLIF S SSPIF S Interrupts cleared Set SSPIF in software SDA = 0, SCL = 1 SDA pulled low by other master. Reset BRG and assert SDA. SCL pulled low after BRG Time-out Set SSPIF '0'PIC18FXX2 DS39564C-page 162 © 2006 Microchip Technology Inc. 15.4.17.2 Bus Collision During a Repeated START Condition During a Repeated START condition, a bus collision occurs if: a) A low level is sampled on SDA when SCL goes from low level to high level. b) SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data ’1’. When the user de-asserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD<6:0> and counts down to 0. The SCL pin is then de-asserted, and when sampled high, the SDA pin is sampled. If SDA is low, a bus collision has occurred (i.e., another master is attempting to transmit a data ’0’, Figure 15-29). If SDA is sampled high, the BRG is reloaded and begins counting. If SDA goes from high to low before the BRG times out, no bus collision occurs because no two masters can assert SDA at exactly the same time. If SCL goes from high to low before the BRG times out and SDA has not already been asserted, a bus collision occurs. In this case, another master is attempting to transmit a data ’1’ during the Repeated START condition, Figure 15-30. If, at the end of the BRG time-out both SCL and SDA are still high, the SDA pin is driven low and the BRG is reloaded and begins counting. At the end of the count, regardless of the status of the SCL pin, the SCL pin is driven low and the Repeated START condition is complete. FIGURE 15-29: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1) FIGURE 15-30: BUS COLLISION DURING REPEATED START CONDITION (CASE 2) SDA SCL RSEN BCLIF S SSPIF Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. Cleared in software '0' '0' SDA SCL BCLIF RSEN S SSPIF Interrupt cleared in software SCL goes low before SDA, Set BCLIF. Release SDA and SCL. TBRG TBRG '0'© 2006 Microchip Technology Inc. DS39564C-page 163 PIC18FXX2 15.4.17.3 Bus Collision During a STOP Condition Bus collision occurs during a STOP condition if: a) After the SDA pin has been de-asserted and allowed to float high, SDA is sampled low after the BRG has timed out. b) After the SCL pin is de-asserted, SCL is sampled low before SDA goes high. The STOP condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allowed to float. When the pin is sampled high (clock arbitration), the baud rate generator is loaded with SSPADD<6:0> and counts down to 0. After the BRG times out, SDA is sampled. If SDA is sampled low, a bus collision has occurred. This is due to another master attempting to drive a data '0' (Figure 15-31). If the SCL pin is sampled low before SDA is allowed to float high, a bus collision occurs. This is another case of another master attempting to drive a data '0' (Figure 15-32). FIGURE 15-31: BUS COLLISION DURING A STOP CONDITION (CASE 1) FIGURE 15-32: BUS COLLISION DURING A STOP CONDITION (CASE 2) SDA SCL BCLIF PEN P SSPIF TBRG TBRG TBRG SDA asserted low SDA sampled low after TBRG, Set BCLIF '0' '0' SDA SCL BCLIF PEN P SSPIF TBRG TBRG TBRG Assert SDA SCL goes low before SDA goes high Set BCLIF '0' '0'PIC18FXX2 DS39564C-page 164 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 165 PIC18FXX2 16.0 ADDRESSABLE UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (USART) The Universal Synchronous Asynchronous Receiver Transmitter (USART) module is one of the two serial I/O modules. (USART is also known as a Serial Communications Interface or SCI.) The USART can be configured as a full duplex asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers, or it can be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. The USART can be configured in the following modes: • Asynchronous (full-duplex) • Synchronous - Master (half-duplex) • Synchronous - Slave (half-duplex) In order to configure pins RC6/TX/CK and RC7/RX/DT as the Universal Synchronous Asynchronous Receiver Transmitter: • bit SPEN (RCSTA<7>) must be set (= 1), • bit TRISC<6> must be cleared (= 0), and • bit TRISC<7> must be set (=1). Register 16-1 shows the Transmit Status and Control Register (TXSTA) and Register 16-2 shows the Receive Status and Control Register (RCSTA).PIC18FXX2 DS39564C-page 166 © 2006 Microchip Technology Inc. REGISTER 16-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN SYNC — BRGH TRMT TX9D bit 7 bit 0 bit 7 CSRC: Clock Source Select bit Asynchronous mode: Don’t care Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) bit 6 TX9: 9-bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission bit 5 TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled Note: SREN/CREN overrides TXEN in SYNC mode. bit 4 SYNC: USART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 Unimplemented: Read as '0' bit 2 BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode bit 1 TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full bit 0 TX9D: 9th bit of Transmit Data Can be Address/Data bit or a parity bit. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown© 2006 Microchip Technology Inc. DS39564C-page 167 PIC18FXX2 REGISTER 16-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x SPEN RX9 SREN CREN ADDEN FERR OERR RX9D bit 7 bit 0 bit 7 SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins) 0 = Serial port disabled bit 6 RX9: 9-bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5 SREN: Single Receive Enable bit Asynchronous mode: Don’t care Synchronous mode - Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - Slave: Don’t care bit 4 CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN) 0 = Disables continuous receive bit 3 ADDEN: Address Detect Enable bit Asynchronous mode 9-bit (RX9 = 1): 1 = Enables address detection, enable interrupt and load of the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received, and ninth bit can be used as parity bit bit 2 FERR: Framing Error bit 1 = Framing error (can be updated by reading RCREG register and receive next valid byte) 0 = No framing error bit 1 OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit CREN) 0 = No overrun error bit 0 RX9D: 9th bit of Received Data This can be Address/Data bit or a parity bit, and must be calculated by user firmware. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 168 © 2006 Microchip Technology Inc. 16.1 USART Baud Rate Generator (BRG) The BRG supports both the Asynchronous and Synchronous modes of the USART. It is a dedicated 8-bit baud rate generator. The SPBRG register controls the period of a free running 8-bit timer. In Asynchronous mode, bit BRGH (TXSTA<2>) also controls the baud rate. In Synchronous mode, bit BRGH is ignored. Table 16-1 shows the formula for computation of the baud rate for different USART modes, which only apply in Master mode (internal clock). Given the desired baud rate and Fosc, the nearest integer value for the SPBRG register can be calculated using the formula in Table 16-1. From this, the error in baud rate can be determined. Example 16-1 shows the calculation of the baud rate error for the following conditions: • FOSC = 16 MHz • Desired Baud Rate = 9600 • BRGH = 0 • SYNC = 0 It may be advantageous to use the high baud rate (BRGH = 1) even for slower baud clocks. This is because the FOSC/(16(X + 1)) equation can reduce the baud rate error in some cases. Writing a new value to the SPBRG register causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate. 16.1.1 SAMPLING The data on the RC7/RX/DT pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX pin. EXAMPLE 16-1: CALCULATING BAUD RATE ERROR TABLE 16-1: BAUD RATE FORMULA TABLE 16-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR Desired Baud Rate = FOSC / (64 (X + 1)) Solving for X: X = ( (FOSC / Desired Baud Rate) / 64 ) – 1 X = ((16000000 / 9600) / 64) – 1 X = [25.042] = 25 Calculated Baud Rate = 16000000 / (64 (25 + 1)) = 9615 Error = (Calculated Baud Rate – Desired Baud Rate) Desired Baud Rate = (9615 – 9600) / 9600 = 0.16% SYNC BRGH = 0 (Low Speed) BRGH = 1 (High Speed) 0 1 (Asynchronous) Baud Rate = FOSC/(64(X+1)) (Synchronous) Baud Rate = FOSC/(4(X+1)) Baud Rate = FOSC/(16(X+1)) N/A Legend: X = value in SPBRG (0 to 255) Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used by the BRG.© 2006 Microchip Technology Inc. DS39564C-page 169 PIC18FXX2 TABLE 16-3: BAUD RATES FOR SYNCHRONOUS MODE BAUD RATE (Kbps) FOSC = 40 MHz SPBRG value (decimal) 33 MHz SPBRG value (decimal) 25 MHz SPBRG value (decimal) 20 MHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - NA - - 1.2 NA - - NA - - NA - - NA - - 2.4 NA - - NA - - NA - - NA - - 9.6 NA - - NA - - NA - - NA - - 19.2 NA - - NA - - NA - - NA - - 76.8 76.92 +0.16 129 77.10 +0.39 106 77.16 +0.47 80 76.92 +0.16 64 96 96.15 +0.16 103 95.93 -0.07 85 96.15 +0.16 64 96.15 +0.16 51 300 303.03 +1.01 32 294.64 -1.79 27 297.62 -0.79 20 294.12 -1.96 16 500 500 0 19 485.30 -2.94 16 480.77 -3.85 12 500 0 9 HIGH 10000 - 0 8250 - 0 6250 - 0 5000 - 0 LOW 39.06 - 255 32.23 - 255 24.41 - 255 19.53 - 255 BAUD RATE (Kbps) FOSC = 16 MHz SPBRG value (decimal) 10 MHz SPBRG value (decimal) 7.15909 MHz SPBRG value (decimal) 5.0688 MHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - NA - - 1.2 NA - - NA - - NA - - NA - - 2.4 NA - - NA - - NA - - NA - - 9.6 NA - - NA - - 9.62 +0.23 185 9.60 0 131 19.2 19.23 +0.16 207 19.23 +0.16 129 19.24 +0.23 92 19.20 0 65 76.8 76.92 +0.16 51 75.76 -1.36 32 77.82 +1.32 22 74.54 -2.94 16 96 95.24 -0.79 41 96.15 +0.16 25 94.20 -1.88 18 97.48 +1.54 12 300 307.70 +2.56 12 312.50 +4.17 7 298.35 -0.57 5 316.80 +5.60 3 500 500 0 7 500 0 4 447.44 -10.51 3 422.40 -15.52 2 HIGH 4000 - 0 2500 - 0 1789.80 - 0 1267.20 - 0 LOW 15.63 - 255 9.77 - 255 6.99 - 255 4.95 - 255 BAUD RATE (Kbps) FOSC = 4 MHz SPBRG value (decimal) 3.579545 MHz SPBRG value (decimal) 1 MHz SPBRG value (decimal) 32.768 kHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - 0.30 +1.14 26 1.2 NA - - NA - - 1.20 +0.16 207 1.17 -2.48 6 2.4 NA - - NA - - 2.40 +0.16 103 2.73 +13.78 2 9.6 9.62 +0.16 103 9.62 +0.23 92 9.62 +0.16 25 8.20 -14.67 0 19.2 19.23 +0.16 51 19.04 -0.83 46 19.23 +0.16 12 NA - - 76.8 76.92 +0.16 12 74.57 -2.90 11 83.33 +8.51 2 NA - - 96 1000 +4.17 9 99.43 +3.57 8 83.33 -13.19 2 NA - - 300 333.33 +11.11 2 298.30 -0.57 2 250 -16.67 0 NA - - 500 500 0 1 447.44 -10.51 1 NA - - NA - - HIGH 1000 - 0 894.89 - 0 250 - 0 8.20 - 0 LOW 3.91 - 255 3.50 - 255 0.98 - 255 0.03 - 255PIC18FXX2 DS39564C-page 170 © 2006 Microchip Technology Inc. TABLE 16-4: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0) BAUD RATE (Kbps) FOSC = 40 MHz SPBRG value (decimal) 33 MHz SPBRG value (decimal) 25 MHz SPBRG value (decimal) 20 MHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - NA - - 1.2 NA - - NA - - NA - - NA - - 2.4 NA - - 2.40 -0.07 214 2.40 -0.15 162 2.40 +0.16 129 9.6 9.62 +0.16 64 9.55 -0.54 53 9.53 -0.76 40 9.47 -1.36 32 19.2 18.94 -1.36 32 19.10 -0.54 26 19.53 +1.73 19 19.53 +1.73 15 76.8 78.13 +1.73 7 73.66 -4.09 6 78.13 +1.73 4 78.13 +1.73 3 96 89.29 -6.99 6 103.13 +7.42 4 97.66 +1.73 3 104.17 +8.51 2 300 312.50 +4.17 1 257.81 -14.06 1 NA - - 312.50 +4.17 0 500 625 +25.00 0 NA - - NA - - NA - - HIGH 625 - 0 515.63 - 0 390.63 - 0 312.50 - 0 LOW 2.44 - 255 2.01 - 255 1.53 - 255 1.22 - 255 BAUD RATE (Kbps) FOSC = 16 MHz SPBRG value (decimal) 10 MHz SPBRG value (decimal) 7.15909 MHz SPBRG value (decimal) 5.0688 MHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - NA - - 1.2 1.20 +0.16 207 1.20 +0.16 129 1.20 +0.23 92 1.20 0 65 2.4 2.40 +0.16 103 2.40 +0.16 64 2.38 -0.83 46 2.40 0 32 9.6 9.62 +0.16 25 9.77 +1.73 15 9.32 -2.90 11 9.90 +3.13 7 19.2 19.23 +0.16 12 19.53 +1.73 7 18.64 -2.90 5 19.80 +3.13 3 76.8 83.33 +8.51 2 78.13 +1.73 1 111.86 +45.65 0 79.20 +3.13 0 96 83.33 -13.19 2 78.13 -18.62 1 NA - - NA - - 300 250 -16.67 0 156.25 -47.92 0 NA - - NA - - 500 NA - - NA - - NA - - NA - - HIGH 250 - 0 156.25 - 0 111.86 - 0 79.20 - 0 LOW 0.98 - 255 0.61 - 255 0.44 - 255 0.31 - 255 BAUD RATE (Kbps) FOSC = 4 MHz SPBRG value (decimal) 3.579545 MHz SPBRG value (decimal) 1 MHz SPBRG value (decimal) 32.768 kHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 0.30 -0.16 207 0.30 +0.23 185 0.30 +0.16 51 0.26 -14.67 1 1.2 1.20 +1.67 51 1.19 -0.83 46 1.20 +0.16 12 NA - - 2.4 2.40 +1.67 25 2.43 +1.32 22 2.23 -6.99 6 NA - - 9.6 8.93 -6.99 6 9.32 -2.90 5 7.81 -18.62 1 NA - - 19.2 20.83 +8.51 2 18.64 -2.90 2 15.63 -18.62 0 NA - - 76.8 62.50 -18.62 0 55.93 -27.17 0 NA - - NA - - 96 NA - - NA - - NA - - NA - - 300 NA - - NA - - NA - - NA - - 500 NA - - NA - - NA - - NA - - HIGH 62.50 - 0 55.93 - 0 15.63 - 0 0.51 - 0 LOW 0.24 - 255 0.22 - 255 0.06 - 255 0.002 - 255© 2006 Microchip Technology Inc. DS39564C-page 171 PIC18FXX2 TABLE 16-5: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1) BAUD RATE (Kbps) FOSC = 40 MHz SPBRG value (decimal) 33 MHz SPBRG value (decimal) 25 MHz SPBRG value (decimal) 20 MHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - NA - - 1.2 NA - - NA - - NA - - NA - - 2.4 NA - - NA - - NA - - NA - - 9.6 NA - - 9.60 -0.07 214 9.59 -0.15 162 9.62 +0.16 129 19.2 19.23 +0.16 129 19.28 +0.39 106 19.30 +0.47 80 19.23 +0.16 64 76.8 75.76 -1.36 32 76.39 -0.54 26 78.13 +1.73 19 78.13 +1.73 15 96 96.15 +0.16 25 98.21 +2.31 20 97.66 +1.73 15 96.15 +0.16 12 300 312.50 +4.17 7 294.64 -1.79 6 312.50 +4.17 4 312.50 +4.17 3 500 500 0 4 515.63 +3.13 3 520.83 +4.17 2 416.67 -16.67 2 HIGH 2500 - 0 2062.50 - 0 1562.50 - 0 1250 - 0 LOW 9.77 - 255 8,06 - 255 6.10 - 255 4.88 - 255 BAUD RATE (Kbps) FOSC = 16 MHz SPBRG value (decimal) 10 MHz SPBRG value (decimal) 7.15909 MHz SPBRG value (decimal) 5.0688 MHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - NA - - NA - - 1.2 NA - - NA - - NA - - NA - - 2.4 NA - - NA - - 2.41 +0.23 185 2.40 0 131 9.6 9.62 +0.16 103 9.62 +0.16 64 9.52 -0.83 46 9.60 0 32 19.2 19.23 +0.16 51 18.94 -1.36 32 19.45 +1.32 22 18.64 -2.94 16 76.8 76.92 +0.16 12 78.13 +1.73 7 74.57 -2.90 5 79.20 +3.13 3 96 100 +4.17 9 89.29 -6.99 6 89.49 -6.78 4 105.60 +10.00 2 300 333.33 +11.11 2 312.50 +4.17 1 447.44 +49.15 0 316.80 +5.60 0 500 500 0 1 625 +25.00 0 447.44 -10.51 0 NA - - HIGH 1000 - 0 625 - 0 447.44 - 0 316.80 - 0 LOW 3.91 - 255 2.44 - 255 1.75 - 255 1.24 - 255 BAUD RATE (Kbps) FOSC = 4 MHz SPBRG value (decimal) 3.579545 MHz SPBRG value (decimal) 1 MHz SPBRG value (decimal) 32.768 kHz SPBRG value (decimal) KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR KBAUD % ERROR 0.3 NA - - NA - - 0.30 +0.16 207 0.29 -2.48 6 1.2 1.20 +0.16 207 1.20 +0.23 185 1.20 +0.16 51 1.02 -14.67 1 2.4 2.40 +0.16 103 2.41 +0.23 92 2.40 +0.16 25 2.05 -14.67 0 9.6 9.62 +0.16 25 9.73 +1.32 22 8.93 -6.99 6 NA - - 19.2 19.23 +0.16 12 18.64 -2.90 11 20.83 +8.51 2 NA - - 76.8 NA - - 74.57 -2.90 2 62.50 -18.62 0 NA - - 96 NA - - 111.86 +16.52 1 NA - - NA - - 300 NA - - 223.72 -25.43 0 NA - - NA - - 500 NA - - NA - - NA - - NA - - HIGH 250 - 0 55.93 - 0 62.50 - 0 2.05 - 0 LOW 0.98 - 255 0.22 - 255 0.24 - 255 0.008 - 255PIC18FXX2 DS39564C-page 172 © 2006 Microchip Technology Inc. 16.2 USART Asynchronous Mode In this mode, the USART uses standard non-return-tozero (NRZ) format (one START bit, eight or nine data bits and one STOP bit). The most common data format is 8-bits. An on-chip dedicated 8-bit baud rate generator can be used to derive standard baud rate frequencies from the oscillator. The USART transmits and receives the LSb first. The USART’s transmitter and receiver are functionally independent, but use the same data format and baud rate. The baud rate generator produces a clock, either x16 or x64 of the bit shift rate, depending on bit BRGH (TXSTA<2>). Parity is not supported by the hardware, but can be implemented in software (and stored as the ninth data bit). Asynchronous mode is stopped during SLEEP. Asynchronous mode is selected by clearing bit SYNC (TXSTA<4>). The USART Asynchronous module consists of the following important elements: • Baud Rate Generator • Sampling Circuit • Asynchronous Transmitter • Asynchronous Receiver 16.2.1 USART ASYNCHRONOUS TRANSMITTER The USART transmitter block diagram is shown in Figure 16-1. The heart of the transmitter is the Transmit (serial) Shift Register (TSR). The shift register obtains its data from the read/write transmit buffer, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the STOP bit has been transmitted from the previous load. As soon as the STOP bit is transmitted, the TSR is loaded with new data from the TXREG register (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCY), the TXREG register is empty and flag bit TXIF (PIR1<4>) is set. This interrupt can be enabled/disabled by setting/clearing enable bit TXIE ( PIE1<4>). Flag bit TXIF will be set, regardless of the state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit TXIF indicated the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. Status bit TRMT is a read-only bit, which is set when the TSR register is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. To set up an asynchronous transmission: 1. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH (Section 16.1). 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set transmit bit TX9. Can be used as address/data bit. 5. Enable the transmission by setting bit TXEN, which will also set bit TXIF. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Load data to the TXREG register (starts transmission). FIGURE 16-1: USART TRANSMIT BLOCK DIAGRAM Note 1: The TSR register is not mapped in data memory, so it is not available to the user. 2: Flag bit TXIF is set when enable bit TXEN is set. Note: TXIF is not cleared immediately upon loading data into the transmit buffer TXREG. The flag bit becomes valid in the second instruction cycle following the load instruction. TXIF TXIE Interrupt TXEN Baud Rate CLK SPBRG Baud Rate Generator TX9D MSb LSb Data Bus TXREG Register TSR Register (8) 0 TX9 TRMT SPEN RC6/TX/CK pin Pin Buffer and Control 8 • • •© 2006 Microchip Technology Inc. DS39564C-page 173 PIC18FXX2 FIGURE 16-2: ASYNCHRONOUS TRANSMISSION FIGURE 16-3: ASYNCHRONOUS TRANSMISSION (BACK TO BACK) TABLE 16-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Word 1 STOP bit Word 1 Transmit Shift Reg START bit bit 0 bit 1 bit 7/8 Write to TXREG Word 1 BRG Output (Shift Clock) RC6/TX/CK (pin) TXIF bit (Transmit Buffer Reg. Empty Flag) TRMT bit (Transmit Shift Reg. Empty Flag) Transmit Shift Reg. Write to TXREG BRG Output (Shift Clock) RC6/TX/CK (pin) TXIF bit (Interrupt Reg. Flag) TRMT bit (Transmit Shift Reg. Empty Flag) Word 1 Word 2 Word 1 Word 2 START bit STOP bit START bit Transmit Shift Reg. Word 1 Word 2 bit 0 bit 1 bit 7/8 bit 0 Note: This timing diagram shows two consecutive transmissions. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x TXREG USART Transmit Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Transmission. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.PIC18FXX2 DS39564C-page 174 © 2006 Microchip Technology Inc. 16.2.2 USART ASYNCHRONOUS RECEIVER The receiver block diagram is shown in Figure 16-4. The data is received on the RC7/RX/DT pin and drives the data recovery block. The data recovery block is actually a high speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. To set up an Asynchronous Reception: 1. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH (Section 16.1). 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit RCIE. 4. If 9-bit reception is desired, set bit RX9. 5. Enable the reception by setting bit CREN. 6. Flag bit RCIF will be set when reception is complete and an interrupt will be generated if enable bit RCIE was set. 7. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG register. 9. If any error occurred, clear the error by clearing enable bit CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 16.2.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is required, set the BRGH bit. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RCIP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RCIF bit will be set when reception is complete. The interrupt will be acknowledged if the RCIE and GIE bits are set. 8. Read the RCSTA register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU. FIGURE 16-4: USART RECEIVE BLOCK DIAGRAM x64 Baud Rate CLK SPBRG Baud Rate Generator RC7/RX/DT Pin Buffer and Control SPEN Data Recovery CREN OERR FERR MSb RSR Register LSb RX9D RCREG Register FIFO Interrupt RCIF RCIE Data Bus 8 ÷ 64 ÷ 16 or STOP (8) 7 1 0 START RX9 • • •© 2006 Microchip Technology Inc. DS39564C-page 175 PIC18FXX2 FIGURE 16-5: ASYNCHRONOUS RECEPTION TABLE 16-7: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION START bit bit0 bit1 bit7/8 bit0 STOP bit7/8 bit START bit START bit7/8 STOP bit bit RX (pin) Reg Rcv Buffer Reg Rcv Shift Read Rcv Buffer Reg RCREG RCIF (Interrupt Flag) OERR bit CREN Word 1 RCREG Word 2 RCREG STOP bit Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing the OERR (overrun) bit to be set. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x RCREG USART Receive Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Reception. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.PIC18FXX2 DS39564C-page 176 © 2006 Microchip Technology Inc. 16.3 USART Synchronous Master Mode In Synchronous Master mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit SYNC (TXSTA<4>). In addition, enable bit SPEN (RCSTA<7>) is set in order to configure the RC6/TX/CK and RC7/RX/DT I/O pins to CK (clock) and DT (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK line. The Master mode is entered by setting bit CSRC (TXSTA<7>). 16.3.1 USART SYNCHRONOUS MASTER TRANSMISSION The USART transmitter block diagram is shown in Figure 16-1. The heart of the transmitter is the Transmit (serial) Shift Register (TSR). The shift register obtains its data from the read/write transmit buffer register TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG is empty and interrupt bit TXIF (PIR1<4>) is set. The interrupt can be enabled/disabled by setting/clearing enable bit TXIE (PIE1<4>). Flag bit TXIF will be set, regardless of the state of enable bit TXIE, and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit TXIF indicates the status of the TXREG register, another bit TRMT (TXSTA<1>) shows the status of the TSR register. TRMT is a read only bit, which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory, so it is not available to the user. To set up a Synchronous Master Transmission: 1. Initialize the SPBRG register for the appropriate baud rate (Section 16.1). 2. Enable the synchronous master serial port by setting bits SYNC, SPEN, and CSRC. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set bit TX9. 5. Enable the transmission by setting bit TXEN. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Start transmission by loading data to the TXREG register. TABLE 16-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION Note: TXIF is not cleared immediately upon loading data into the transmit buffer TXREG. The flag bit becomes valid in the second instruction cycle following the load instruction. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x TXREG USART Transmit Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Transmission. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.© 2006 Microchip Technology Inc. DS39564C-page 177 PIC18FXX2 FIGURE 16-6: SYNCHRONOUS TRANSMISSION FIGURE 16-7: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) bit 0 bit 1 bit 7 Word 1 Q1 Q2 Q3Q4 Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3Q4 Q3Q4 Q1 Q2 Q3Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4 RC7/RX/DT bit 2 bit 0 bit 1 bit 7 RC6/TX/CK Write to TXREG Reg TXIF bit (Interrupt Flag) TRMT TXEN bit '1' '1' Word 2 TRMT bit Write Word1 Write Word2 Note: Sync Master mode; SPBRG = '0'. Continuous transmission of two 8-bit words. pin pin RC7/RX/DT pin RC6/TX/CK pin Write to TXREG reg TXIF bit TRMT bit bit0 bit1 bit2 bit6 bit7 TXEN bitPIC18FXX2 DS39564C-page 178 © 2006 Microchip Technology Inc. 16.3.2 USART SYNCHRONOUS MASTER RECEPTION Once Synchronous mode is selected, reception is enabled by setting either enable bit SREN (RCSTA<5>), or enable bit CREN (RCSTA<4>). Data is sampled on the RC7/RX/DT pin on the falling edge of the clock. If enable bit SREN is set, only a single word is received. If enable bit CREN is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. Initialize the SPBRG register for the appropriate baud rate (Section 16.1). 2. Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. 3. Ensure bits CREN and SREN are clear. 4. If interrupts are desired, set enable bit RCIE. 5. If 9-bit reception is desired, set bit RX9. 6. If a single reception is required, set bit SREN. For continuous reception, set bit CREN. 7. Interrupt flag bit RCIF will be set when reception is complete and an interrupt will be generated if the enable bit RCIE was set. 8. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG register. 10. If any error occurred, clear the error by clearing bit CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 16-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION FIGURE 16-8: SYNCHRONOUS RECEPTION (MASTER MODE, SREN) Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x RCREG USART Receive Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Reception. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear. CREN bit RC7/RX/DT pin RC6/TX/CK pin Write to bit SREN SREN bit RCIF bit (Interrupt) Read RXREG Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 '0' bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 '0' Q1 Q2 Q3 Q4 Note: Timing diagram demonstrates Sync Master mode with bit SREN = '1' and bit BRGH = '0'.© 2006 Microchip Technology Inc. DS39564C-page 179 PIC18FXX2 16.4 USART Synchronous Slave Mode Synchronous Slave mode differs from the Master mode in the fact that the shift clock is supplied externally at the RC6/TX/CK pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in SLEEP mode. Slave mode is entered by clearing bit CSRC (TXSTA<7>). 16.4.1 USART SYNCHRONOUS SLAVE TRANSMIT The operation of the Synchronous Master and Slave modes are identical, except in the case of the SLEEP mode. If two words are written to the TXREG and then the SLEEP instruction is executed, the following will occur: a) The first word will immediately transfer to the TSR register and transmit. b) The second word will remain in TXREG register. c) Flag bit TXIF will not be set. d) When the first word has been shifted out of TSR, the TXREG register will transfer the second word to the TSR and flag bit TXIF will now be set. e) If enable bit TXIE is set, the interrupt will wake the chip from SLEEP. If the global interrupt is enabled, the program will branch to the interrupt vector. To set up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting bits SYNC and SPEN and clearing bit CSRC. 2. Clear bits CREN and SREN. 3. If interrupts are desired, set enable bit TXIE. 4. If 9-bit transmission is desired, set bit TX9. 5. Enable the transmission by setting enable bit TXEN. 6. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. 7. Start transmission by loading data to the TXREG register. 8. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x TXREG USART Transmit Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Slave Transmission. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.PIC18FXX2 DS39564C-page 180 © 2006 Microchip Technology Inc. 16.4.2 USART SYNCHRONOUS SLAVE RECEPTION The operation of the Synchronous Master and Slave modes is identical, except in the case of the SLEEP mode and bit SREN, which is a “don't care” in Slave mode. If receive is enabled by setting bit CREN prior to the SLEEP instruction, then a word may be received during SLEEP. On completely receiving the word, the RSR register will transfer the data to the RCREG register, and if enable bit RCIE bit is set, the interrupt generated will wake the chip from SLEEP. If the global interrupt is enabled, the program will branch to the interrupt vector. To set up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting bits SYNC and SPEN and clearing bit CSRC. 2. If interrupts are desired, set enable bit RCIE. 3. If 9-bit reception is desired, set bit RX9. 4. To enable reception, set enable bit CREN. 5. Flag bit RCIF will be set when reception is complete. An interrupt will be generated if enable bit RCIE was set. 6. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 7. Read the 8-bit received data by reading the RCREG register. 8. If any error occurred, clear the error by clearing bit CREN. 9. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 16-11: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x RCREG USART Receive Register 0000 0000 0000 0000 TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010 SPBRG Baud Rate Generator Register 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Slave Reception. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.© 2006 Microchip Technology Inc. DS39564C-page 181 PIC18FXX2 17.0 COMPATIBLE 10-BIT ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE The Analog-to-Digital (A/D) converter module has five inputs for the PIC18F2X2 devices and eight for the PIC18F4X2 devices. This module has the ADCON0 and ADCON1 register definitions that are compatible with the mid-range A/D module. The A/D allows conversion of an analog input signal to a corresponding 10-bit digital number. The A/D module has four registers. These registers are: • A/D Result High Register (ADRESH) • A/D Result Low Register (ADRESL) • A/D Control Register 0 (ADCON0) • A/D Control Register 1 (ADCON1) The ADCON0 register, shown in Register 17-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 17-2, configures the functions of the port pins. REGISTER 17-1: ADCON0 REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE — ADON bit 7 bit 0 bit 7-6 ADCS1:ADCS0: A/D Conversion Clock Select bits (ADCON0 bits in bold) bit 5-3 CHS2:CHS0: Analog Channel Select bits 000 = channel 0, (AN0) 001 = channel 1, (AN1) 010 = channel 2, (AN2) 011 = channel 3, (AN3) 100 = channel 4, (AN4) 101 = channel 5, (AN5) 110 = channel 6, (AN6) 111 = channel 7, (AN7) Note: The PIC18F2X2 devices do not implement the full 8 A/D channels; the unimplemented selections are reserved. Do not select any unimplemented channel. bit 2 GO/DONE: A/D Conversion Status bit When ADON = 1: 1 = A/D conversion in progress (setting this bit starts the A/D conversion which is automatically cleared by hardware when the A/D conversion is complete) 0 = A/D conversion not in progress bit 1 Unimplemented: Read as '0' bit 0 ADON: A/D On bit 1 = A/D converter module is powered up 0 = A/D converter module is shut-off and consumes no operating current Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown ADCON1 ADCON0 Clock Conversion 0 00 FOSC/2 0 01 FOSC/8 0 10 FOSC/32 0 11 FRC (clock derived from the internal A/D RC oscillator) 1 00 FOSC/4 1 01 FOSC/16 1 10 FOSC/64 1 11 FRC (clock derived from the internal A/D RC oscillator)PIC18FXX2 DS39564C-page 182 © 2006 Microchip Technology Inc. REGISTER 17-2: ADCON1 REGISTER R/W-0 R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 ADFM ADCS2 — — PCFG3 PCFG2 PCFG1 PCFG0 bit 7 bit 0 bit 7 ADFM: A/D Result Format Select bit 1 = Right justified. Six (6) Most Significant bits of ADRESH are read as ’0’. 0 = Left justified. Six (6) Least Significant bits of ADRESL are read as ’0’. bit 6 ADCS2: A/D Conversion Clock Select bit (ADCON1 bits in bold) bit 5-4 Unimplemented: Read as '0' bit 3-0 PCFG3:PCFG0: A/D Port Configuration Control bits Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown Note: On any device RESET, the port pins that are multiplexed with analog functions (ANx) are forced to be an analog input. ADCON1 ADCON0 Clock Conversion 0 00 FOSC/2 0 01 FOSC/8 0 10 FOSC/32 0 11 FRC (clock derived from the internal A/D RC oscillator) 1 00 FOSC/4 1 01 FOSC/16 1 10 FOSC/64 1 11 FRC (clock derived from the internal A/D RC oscillator) A = Analog input D = Digital I/O C/R = # of analog input channels / # of A/D voltage references PCFG <3:0> AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 VREF+ VREF- C / R 0000 A AAA A A AAVDD VSS 8 / 0 0001 A A A AVREF+ A A A AN3 VSS 7 / 1 0010 DDDA A A AAVDD VSS 5 / 0 0011 D D D AVREF+ A A A AN3 VSS 4 / 1 0100 DDDD A D AAVDD VSS 3 / 0 0101 D D D DVREF+ D A A AN3 VSS 2 / 1 011x D D D D D D D D — — 0 / 0 1000 A A A AVREF+ VREF- A A AN3 AN2 6 / 2 1001 DDAA A A AAVDD VSS 6 / 0 1010 D D A AVREF+ A A A AN3 VSS 5 / 1 1011 D D A AVREF+ VREF- A A AN3 AN2 4 / 2 1100 D D D AVREF+ VREF- A A AN3 AN2 3 / 2 1101 D D D DVREF+ VREF- A A AN3 AN2 2 / 2 1110 DDDD D D DAVDD VSS 1 / 0 1111 D D D DVREF+ VREF- D A AN3 AN2 1 / 2© 2006 Microchip Technology Inc. DS39564C-page 183 PIC18FXX2 The analog reference voltage is software selectable to either the device’s positive and negative supply voltage (VDD and VSS), or the voltage level on the RA3/AN3/ VREF+ pin and RA2/AN2/VREF- pin. The A/D converter has a unique feature of being able to operate while the device is in SLEEP mode. To operate in SLEEP, the A/D conversion clock must be derived from the A/D’s internal RC oscillator. The output of the sample and hold is the input into the converter, which generates the result via successive approximation. A device RESET forces all registers to their RESET state. This forces the A/D module to be turned off and any conversion is aborted. Each port pin associated with the A/D converter can be configured as an analog input (RA3 can also be a voltage reference) or as a digital I/O. The ADRESH and ADRESL registers contain the result of the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH/ ADRESL registers, the GO/DONE bit (ADCON0<2>) is cleared, and A/D interrupt flag bit, ADIF is set. The block diagram of the A/D module is shown in Figure 17-1. FIGURE 17-1: A/D BLOCK DIAGRAM (Input Voltage) VAIN VREF+ Reference Voltage VDD PCFG<3:0> CHS<2:0> AN7* AN6* AN5* AN4 AN3 AN2 AN1 AN0 111 110 101 100 011 010 001 000 10-bit Converter VREFVSS A/D * These channels are implemented only on the PIC18F4X2 devices.PIC18FXX2 DS39564C-page 184 © 2006 Microchip Technology Inc. The value that is in the ADRESH/ADRESL registers is not modified for a Power-on Reset. The ADRESH/ ADRESL registers will contain unknown data after a Power-on Reset. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as an input. To determine acquisition time, see Section 17.1. After this acquisition time has elapsed, the A/D conversion can be started. The following steps should be followed for doing an A/D conversion: 1. Configure the A/D module: • Configure analog pins, voltage reference and digital I/O (ADCON1) • Select A/D input channel (ADCON0) • Select A/D conversion clock (ADCON0) • Turn on A/D module (ADCON0) 2. Configure A/D interrupt (if desired): • Clear ADIF bit • Set ADIE bit • Set GIE bit • Set PEIE bit 3. Wait the required acquisition time. 4. Start conversion: • Set GO/DONE bit (ADCON0) 5. Wait for A/D conversion to complete, by either: • Polling for the GO/DONE bit to be cleared (interrupts disabled) OR • Waiting for the A/D interrupt 6. Read A/D Result registers (ADRESH/ADRESL); clear bit ADIF if required. 7. For next conversion, go to step 1 or step 2 as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2 TAD is required before the next acquisition starts. 17.1 A/D Acquisition Requirements For the A/D converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 17-2. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD). The source impedance affects the offset voltage at the analog input (due to pin leakage current). The maximum recommended impedance for analog sources is 2.5 kΩ. After the analog input channel is selected (changed), this acquisition must be done before the conversion can be started. FIGURE 17-2: ANALOG INPUT MODEL Note: When the conversion is started, the holding capacitor is disconnected from the input pin. VAIN CPIN Rs ANx 5 pF VDD VT = 0.6V VT = 0.6V I LEAKAGE RIC ≤ 1k Sampling Switch SS RSS CHOLD = 120 pF VSS 6V Sampling Switch 5V 4V 3V 2V 5 6 7 8 9 10 11 (kΩ) VDD ± 500 nA Legend: CPIN VT I LEAKAGE RIC SS CHOLD = input capacitance = threshold voltage = leakage current at the pin due to = interconnect resistance = sampling switch = sample/hold capacitance (from DAC) various junctions© 2006 Microchip Technology Inc. DS39564C-page 185 PIC18FXX2 To calculate the minimum acquisition time, Equation 17-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. EQUATION 17-1: ACQUISITION TIME EQUATION 17-2: A/D MINIMUM CHARGING TIME Example 17-1 shows the calculation of the minimum required acquisition time, TACQ. This calculation is based on the following application system assumptions: • CHOLD = 120 pF • Rs = 2.5 kΩ • Conversion Error ≤ 1/2 LSb • VDD = 5V → Rss = 7 kΩ • Temperature = 50°C (system max.) • VHOLD = 0V @ time = 0 EXAMPLE 17-1: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME TACQ = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient = TAMP + TC + TCOFF VHOLD = (VREF – (VREF/2048)) • (1 – e(-Tc/CHOLD(RIC + RSS + RS))) or TC = -(120 pF)(1 kΩ + RSS + RS) ln(1/2048) TACQ = TAMP + TC + TCOFF Temperature coefficient is only required for temperatures > 25°C. TACQ = 2 μs + TC + [(Temp – 25°C)(0.05 μs/°C)] TC = -CHOLD (RIC + RSS + RS) ln(1/2048) -120 pF (1 kΩ + 7 kΩ + 2.5 kΩ) ln(0.0004883) -120 pF (10.5 kΩ) ln(0.0004883) -1.26 μs (-7.6246) 9.61 μs TACQ = 2 μs + 9.61 μs + [(50°C – 25°C)(0.05 μs/°C)] 11.61 μs + 1.25 μs 12.86 μsPIC18FXX2 DS39564C-page 186 © 2006 Microchip Technology Inc. 17.2 Selecting the A/D Conversion Clock The A/D conversion time per bit is defined as TAD. The A/D conversion requires 12 TAD per 10-bit conversion. The source of the A/D conversion clock is software selectable. The seven possible options for TAD are: • 2 TOSC • 4 TOSC • 8 TOSC • 16 TOSC • 32 TOSC • 64 TOSC • Internal A/D module RC oscillator (2-6 μs) For correct A/D conversions, the A/D conversion clock (TAD) must be selected to ensure a minimum TAD time of 1.6 μs. Table 17-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. 17.3 Configuring Analog Port Pins The ADCON1, TRISA and TRISE registers control the operation of the A/D port pins. The port pins that are desired as analog inputs, must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS2:CHS0 bits and the TRIS bits. TABLE 17-1: TAD vs. DEVICE OPERATING FREQUENCIES Note 1: When reading the port register, all pins configured as analog input channels will read as cleared (a low level). Pins configured as digital inputs will convert an analog input. Analog levels on a digitally configured input will not affect the conversion accuracy. 2: Analog levels on any pin that is defined as a digital input (including the AN4:AN0 pins) may cause the input buffer to consume current that is out of the device’s specification. AD Clock Source (TAD) Maximum Device Frequency Operation ADCS2:ADCS0 PIC18FXX2 PIC18LFXX2 2 TOSC 000 1.25 MHz 666 kHz 4 TOSC 100 2.50 MHz 1.33 MHz 8 TOSC 001 5.00 MHz 2.67 MHz 16 TOSC 101 10.00 MHz 5.33 MHz 32 TOSC 010 20.00 MHz 10.67 MHz 64 TOSC 110 40.00 MHz 21.33 MHz RC 011 — —© 2006 Microchip Technology Inc. DS39564C-page 187 PIC18FXX2 17.4 A/D Conversions Figure 17-3 shows the operation of the A/D converter after the GO bit has been set. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D result register pair will NOT be updated with the partially completed A/D conversion sample. That is, the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is aborted, a 2 TAD wait is required before the next acquisition is started. After this 2 TAD wait, acquisition on the selected channel is automatically started. The GO/DONE bit can then be set to start the conversion. FIGURE 17-3: A/D CONVERSION TAD CYCLES 17.4.1 A/D RESULT REGISTERS The ADRESH:ADRESL register pair is the location where the 10-bit A/D result is loaded at the completion of the A/D conversion. This register pair is 16-bits wide. The A/D module gives the flexibility to left or right justify the 10-bit result in the 16-bit result register. The A/D Format Select bit (ADFM) controls this justification. Figure 17-4 shows the operation of the A/D result justification. The extra bits are loaded with ’0’s. When an A/D result will not overwrite these locations (A/D disable), these registers may be used as two general purpose 8-bit registers. FIGURE 17-4: A/D RESULT JUSTIFICATION Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D. TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD11 Set GO bit Holding capacitor is disconnected from analog input (typically 100 ns) b9 b8 b7 b6 b5 b4 b3 b2 TAD9 TAD10 b1 b0 TCY - TAD Next Q4: ADRESH/ADRESL is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. Conversion Starts b0 10-bit Result ADRESH ADRESL 0000 00 ADFM = 0 7 2 1 0 7 0 10-bit Result ADRESH ADRESL 10-bit Result 0000 00 7 0 7 6 5 0 ADFM = 1 Right Justified Left JustifiedPIC18FXX2 DS39564C-page 188 © 2006 Microchip Technology Inc. 17.5 Use of the CCP2 Trigger An A/D conversion can be started by the “special event trigger” of the CCP2 module. This requires that the CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be programmed as 1011 and that the A/D module is enabled (ADON bit is set). When the trigger occurs, the GO/ DONE bit will be set, starting the A/D conversion, and the Timer1 (or Timer3) counter will be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal software overhead (moving ADRESH/ADRESL to the desired location). The appropriate analog input channel must be selected and the minimum acquisition done before the “special event trigger” sets the GO/DONE bit (starts a conversion). If the A/D module is not enabled (ADON is cleared), the “special event trigger” will be ignored by the A/D module, but will still reset the Timer1 (or Timer3) counter. TABLE 17-2: SUMMARY OF A/D REGISTERS Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Value on All Other RESETS INTCON GIE/ GIEH PEIE/ GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000 PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000 IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 0000 ADRESH A/D Result Register xxxx xxxx uuuu uuuu ADRESL A/D Result Register xxxx xxxx uuuu uuuu ADCON0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE — ADON 0000 00-0 0000 00-0 ADCON1 ADFM ADCS2 — — PCFG3 PCFG2 PCFG1 PCFG0 ---- -000 ---- -000 PORTA — RA6 RA5 RA4 RA3 RA2 RA1 RA0 --0x 0000 --0u 0000 TRISA — PORTA Data Direction Register --11 1111 --11 1111 PORTE — — — — — RE2 RE1 RE0 ---- -000 ---- -000 LATE — — — — — LATE2 LATE1 LATE0 ---- -xxx ---- -uuu TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111 Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for A/D conversion. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.© 2006 Microchip Technology Inc. DS39564C-page 189 PIC18FXX2 18.0 LOW VOLTAGE DETECT In many applications, the ability to determine if the device voltage (VDD) is below a specified voltage level is a desirable feature. A window of operation for the application can be created, where the application software can do “housekeeping tasks” before the device voltage exits the valid operating range. This can be done using the Low Voltage Detect module. This module is a software programmable circuitry, where a device voltage trip point can be specified. When the voltage of the device becomes lower then the specified point, an interrupt flag is set. If the interrupt is enabled, the program execution will branch to the interrupt vector address and the software can then respond to that interrupt source. The Low Voltage Detect circuitry is completely under software control. This allows the circuitry to be “turned off” by the software, which minimizes the current consumption for the device. Figure 18-1 shows a possible application voltage curve (typically for batteries). Over time, the device voltage decreases. When the device voltage equals voltage VA, the LVD logic generates an interrupt. This occurs at time TA. The application software then has the time, until the device voltage is no longer in valid operating range, to shutdown the system. Voltage point VB is the minimum valid operating voltage specification. This occurs at time TB. The difference TB - TA is the total time for shutdown. FIGURE 18-1: TYPICAL LOW VOLTAGE DETECT APPLICATION The block diagram for the LVD module is shown in Figure 18-2. A comparator uses an internally generated reference voltage as the set point. When the selected tap output of the device voltage crosses the set point (is lower than), the LVDIF bit is set. Each node in the resistor divider represents a “trip point” voltage. The “trip point” voltage is the minimum supply voltage level at which the device can operate before the LVD module asserts an interrupt. When the supply voltage is equal to the trip point, the voltage tapped off of the resistor array is equal to the 1.2V internal reference voltage generated by the voltage reference module. The comparator then generates an interrupt signal setting the LVDIF bit. This voltage is software programmable to any one of 16 values (see Figure 18-2). The trip point is selected by programming the LVDL3:LVDL0 bits (LVDCON<3:0>). Time Voltage VA VB TA TB VA = LVD trip point VB = Minimum valid device operating voltage Legend:PIC18FXX2 DS39564C-page 190 © 2006 Microchip Technology Inc. FIGURE 18-2: LOW VOLTAGE DETECT (LVD) BLOCK DIAGRAM The LVD module has an additional feature that allows the user to supply the trip voltage to the module from an external source. This mode is enabled when bits LVDL3:LVDL0 are set to 1111. In this state, the comparator input is multiplexed from the external input pin, LVDIN (Figure 18-3). This gives users flexibility, because it allows them to configure the Low Voltage Detect interrupt to occur at any voltage in the valid operating range. FIGURE 18-3: LOW VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM LVDIF VDD 16 to 1 MUX LVDEN LVD Control Register Internally Generated Reference Voltage LVDIN 1.2V Typical – + LVD EN LVD Control 16 to 1 MUX BGAP BODEN LVDEN VxEN LVDIN Register VDD VDD Externally Generated Trip Point – +© 2006 Microchip Technology Inc. DS39564C-page 191 PIC18FXX2 18.1 Control Register The Low Voltage Detect Control register controls the operation of the Low Voltage Detect circuitry. REGISTER 18-1: LVDCON REGISTER U-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1 — — IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 bit 7 bit 0 bit 7-6 Unimplemented: Read as '0' bit 5 IRVST: Internal Reference Voltage Stable Flag bit 1 = Indicates that the Low Voltage Detect logic will generate the interrupt flag at the specified voltage range 0 = Indicates that the Low Voltage Detect logic will not generate the interrupt flag at the specified voltage range and the LVD interrupt should not be enabled bit 4 LVDEN: Low Voltage Detect Power Enable bit 1 = Enables LVD, powers up LVD circuit 0 = Disables LVD, powers down LVD circuit bit 3-0 LVDL3:LVDL0: Low Voltage Detection Limit bits 1111 = External analog input is used (input comes from the LVDIN pin) 1110 = 4.5V - 4.77V 1101 = 4.2V - 4.45V 1100 = 4.0V - 4.24V 1011 = 3.8V - 4.03V 1010 = 3.6V - 3.82V 1001 = 3.5V - 3.71V 1000 = 3.3V - 3.50V 0111 = 3.0V - 3.18V 0110 = 2.8V - 2.97V 0101 = 2.7V - 2.86V 0100 = 2.5V - 2.65V 0011 = 2.4V - 2.54V 0010 = 2.2V - 2.33V 0001 = 2.0V - 2.12V 0000 = Reserved Note: LVDL3:LVDL0 modes which result in a trip point below the valid operating voltage of the device are not tested. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknownPIC18FXX2 DS39564C-page 192 © 2006 Microchip Technology Inc. 18.2 Operation Depending on the power source for the device voltage, the voltage normally decreases relatively slowly. This means that the LVD module does not need to be constantly operating. To decrease the current requirements, the LVD circuitry only needs to be enabled for short periods, where the voltage is checked. After doing the check, the LVD module may be disabled. Each time that the LVD module is enabled, the circuitry requires some time to stabilize. After the circuitry has stabilized, all status flags may be cleared. The module will then indicate the proper state of the system. The following steps are needed to set up the LVD module: 1. Write the value to the LVDL3:LVDL0 bits (LVDCON register), which selects the desired LVD Trip Point. 2. Ensure that LVD interrupts are disabled (the LVDIE bit is cleared or the GIE bit is cleared). 3. Enable the LVD module (set the LVDEN bit in the LVDCON register). 4. Wait for the LVD module to stabilize (the IRVST bit to become set). 5. Clear the LVD interrupt flag, which may have falsely become set until the LVD module has stabilized (clear the LVDIF bit). 6. Enable the LVD interrupt (set the LVDIE and the GIE bits). Figure 18-4 shows typical waveforms that the LVD module may be used to detect. FIGURE 18-4: LOW VOLTAGE DETECT WAVEFORMS VLVD VDD LVDIF VLVD VDD Enable LVD Internally Generated TIVRST LVDIF may not be set Enable LVD LVDIF LVDIF cleared in software LVDIF cleared in software LVDIF cleared in software, CASE 1: CASE 2: LVDIF remains set since LVD condition still exists Reference Stable Internally Generated Reference Stable TIVRST© 2006 Microchip Technology Inc. DS39564C-page 193 PIC18FXX2 18.2.1 REFERENCE VOLTAGE SET POINT The Internal Reference Voltage of the LVD module may be used by other internal circuitry (the Programmable Brown-out Reset). If these circuits are disabled (lower current consumption), the reference voltage circuit requires a time to become stable before a low voltage condition can be reliably detected. This time is invariant of system clock speed. This start-up time is specified in electrical specification parameter 36. The low voltage interrupt flag will not be enabled until a stable reference voltage is reached. Refer to the waveform in Figure 18-4. 18.2.2 CURRENT CONSUMPTION When the module is enabled, the LVD comparator and voltage divider are enabled and will consume static current. The voltage divider can be tapped from multiple places in the resistor array. Total current consumption, when enabled, is specified in electrical specification parameter #D022B. 18.3 Operation During SLEEP When enabled, the LVD circuitry continues to operate during SLEEP. If the device voltage crosses the trip point, the LVDIF bit will be set and the device will wakeup from SLEEP. Device execution will continue from the interrupt vector address if interrupts have been globally enabled. 18.4 Effects of a RESET A device RESET forces all registers to their RESET state. This forces the LVD module to be turned off. PIC18FXX2 DS39564C-page 194 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 195 PIC18FXX2 19.0 SPECIAL FEATURES OF THE CPU There are several features intended to maximize system reliability, minimize cost through elimination of external components, provide power saving Operating modes and offer code protection. These are: • OSC Selection • RESET - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) • Interrupts • Watchdog Timer (WDT) • SLEEP • Code Protection • ID Locations • In-Circuit Serial Programming All PIC18FXX2 devices have a Watchdog Timer, which is permanently enabled via the configuration bits or software controlled. It runs off its own RC oscillator for added reliability. There are two timers that offer necessary delays on power-up. One is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable. The other is the Powerup Timer (PWRT), which provides a fixed delay on power-up only, designed to keep the part in RESET while the power supply stabilizes. With these two timers on-chip, most applications need no external RESET circuitry. SLEEP mode is designed to offer a very low current Power-down mode. The user can wake-up from SLEEP through external RESET, Watchdog Timer Wake-up or through an interrupt. Several oscillator options are also made available to allow the part to fit the application. The RC oscillator option saves system cost, while the LP crystal option saves power. A set of configuration bits are used to select various options. 19.1 Configuration Bits The configuration bits can be programmed (read as '0'), or left unprogrammed (read as '1'), to select various device configurations. These bits are mapped starting at program memory location 300000h. The user will note that address 300000h is beyond the user program memory space. In fact, it belongs to the configuration memory space (300000h - 3FFFFFh), which can only be accessed using Table Reads and Table Writes. Programming the configuration registers is done in a manner similar to programming the FLASH memory (see Section 5.5.1). The only difference is the configuration registers are written a byte at a time. The sequence of events for programming configuration registers is: 1. Load table pointer with address of configuration register being written. 2. Write a single byte using the TBLWT instruction. 3. Set EEPGD to point to program memory, set the CFGS bit to access configuration registers, and set WREN to enable byte writes. 4. Disable interrupts. 5. Write 55h to EECON2. 6. Write AAh to EECON2. 7. Set the WR bit. This will begin the write cycle. 8. CPU will stall for duration of write (approximately 2 ms using internal timer). 9. Execute a NOP. 10. Re-enable interrupts.PIC18FXX2 DS39564C-page 196 © 2006 Microchip Technology Inc. TABLE 19-1: CONFIGURATION BITS AND DEVICE IDS REGISTER 19-1: CONFIGURATION REGISTER 1 HIGH (CONFIG1H: BYTE ADDRESS 300001h) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Default/ Unprogrammed Value 300001h CONFIG1H — — OSCSEN — — FOSC2 FOSC1 FOSC0 --1- -111 300002h CONFIG2L — — — — BORV1 BORV0 BOREN PWRTEN ---- 1111 300003h CONFIG2H — — — — WDTPS2 WDTPS1 WDTPS0 WDTEN ---- 1111 300005h CONFIG3H — — — — — — — CCP2MX ---- ---1 300006h CONFIG4L DEBUG — — — — LVP — STVREN 1--- -1-1 300008h CONFIG5L — — — — CP3 CP2 CP1 CP0 ---- 1111 300009h CONFIG5H CPD CPB — — — — — — 11-- ---- 30000Ah CONFIG6L — — — — WRT3 WRT2 WRT1 WRT0 ---- 1111 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 111- ---- 30000Ch CONFIG7L — — — — EBTR3 EBTR2 EBTR1 EBTR0 ---- 1111 30000Dh CONFIG7H — EBTRB — — — — — — -1-- ---- 3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 (1) 3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0000 0100 Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as ‘0’. Note 1: See Register 19-12 for DEVID1 values. U-0 U-0 R/P-1 U-0 U-0 R/P-1 R/P-1 R/P-1 — — OSCSEN — — FOSC2 FOSC1 FOSC0 bit 7 bit 0 bit 7-6 Unimplemented: Read as ‘0’ bit 5 OSCSEN: Oscillator System Clock Switch Enable bit 1 = Oscillator system clock switch option is disabled (main oscillator is source) 0 = Oscillator system clock switch option is enabled (oscillator switching is enabled) bit 4-3 Unimplemented: Read as ‘0’ bit 2-0 FOSC2:FOSC0: Oscillator Selection bits 111 = RC oscillator w/ OSC2 configured as RA6 110 = HS oscillator with PLL enabled/Clock frequency = (4 x FOSC) 101 = EC oscillator w/ OSC2 configured as RA6 100 = EC oscillator w/ OSC2 configured as divide-by-4 clock output 011 = RC oscillator 010 = HS oscillator 001 = XT oscillator 000 = LP oscillator Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state© 2006 Microchip Technology Inc. DS39564C-page 197 PIC18FXX2 REGISTER 19-2: CONFIGURATION REGISTER 2 LOW (CONFIG2L: BYTE ADDRESS 300002h) REGISTER 19-3: CONFIGURATION REGISTER 2 HIGH (CONFIG2H: BYTE ADDRESS 300003h) U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 — — — — BORV1 BORV0 BOREN PWRTEN bit 7 bit 0 bit 7-4 Unimplemented: Read as ‘0’ bit 3-2 BORV1:BORV0: Brown-out Reset Voltage bits 11 = VBOR set to 2.5V 10 = VBOR set to 2.7V 01 = VBOR set to 4.2V 00 = VBOR set to 4.5V bit 1 BOREN: Brown-out Reset Enable bit 1 = Brown-out Reset enabled 0 = Brown-out Reset disabled bit 0 PWRTEN: Power-up Timer Enable bit 1 = PWRT disabled 0 = PWRT enabled Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 — — — — WDTPS2 WDTPS1 WDTPS0 WDTEN bit 7 bit 0 bit 7-4 Unimplemented: Read as ‘0’ bit 3-1 WDTPS2:WDTPS0: Watchdog Timer Postscale Select bits 111 = 1:128 110 = 1:64 101 = 1:32 100 = 1:16 011 = 1:8 010 = 1:4 001 = 1:2 000 = 1:1 bit 0 WDTEN: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled (control is placed on the SWDTEN bit) Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed statePIC18FXX2 DS39564C-page 198 © 2006 Microchip Technology Inc. REGISTER 19-4: CONFIGURATION REGISTER 3 HIGH (CONFIG3H: BYTE ADDRESS 300005h) REGISTER 19-5: CONFIGURATION REGISTER 4 LOW (CONFIG4L: BYTE ADDRESS 300006h) U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/P-1 — — — — — — — CCP2MX bit 7 bit 0 bit 7-1 Unimplemented: Read as ‘0’ bit 0 CCP2MX: CCP2 Mux bit 1 = CCP2 input/output is multiplexed with RC1 0 = CCP2 input/output is multiplexed with RB3 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state R/P-1 U-0 U-0 U-0 U-0 R/P-1 U-0 R/P-1 BKBUG — — — — LVP — STVREN bit 7 bit 0 bit 7 DEBUG: Background Debugger Enable bit 1 = Background Debugger disabled. RB6 and RB7 configured as general purpose I/O pins. 0 = Background Debugger enabled. RB6 and RB7 are dedicated to In-Circuit Debug. bit 6-3 Unimplemented: Read as ‘0’ bit 2 LVP: Low Voltage ICSP Enable bit 1 = Low Voltage ICSP enabled 0 = Low Voltage ICSP disabled bit 1 Unimplemented: Read as ‘0’ bit 0 STVREN: Stack Full/Underflow Reset Enable bit 1 = Stack Full/Underflow will cause RESET 0 = Stack Full/Underflow will not cause RESET Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state© 2006 Microchip Technology Inc. DS39564C-page 199 PIC18FXX2 REGISTER 19-6: CONFIGURATION REGISTER 5 LOW (CONFIG5L: BYTE ADDRESS 300008h) REGISTER 19-7: CONFIGURATION REGISTER 5 HIGH (CONFIG5H: BYTE ADDRESS 300009h) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — CP3(1) CP2(1) CP1 CP0 bit 7 bit 0 bit 7-4 Unimplemented: Read as ‘0’ bit 3 CP3: Code Protection bit(1) 1 = Block 3 (006000-007FFFh) not code protected 0 = Block 3 (006000-007FFFh) code protected bit 2 CP2: Code Protection bit(1) 1 = Block 2 (004000-005FFFh) not code protected 0 = Block 2 (004000-005FFFh) code protected bit 1 CP1: Code Protection bit 1 = Block 1 (002000-003FFFh) not code protected 0 = Block 1 (002000-003FFFh) code protected bit 0 CP0: Code Protection bit 1 = Block 0 (000200-001FFFh) not code protected 0 = Block 0 (000200-001FFFh) code protected Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set. Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state R/C-1 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 CPD CPB — — — — — — bit 7 bit 0 bit 7 CPD: Data EEPROM Code Protection bit 1 = Data EEPROM not code protected 0 = Data EEPROM code protected bit 6 CPB: Boot Block Code Protection bit 1 = Boot Block (000000-0001FFh) not code protected 0 = Boot Block (000000-0001FFh) code protected bit 5-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed statePIC18FXX2 DS39564C-page 200 © 2006 Microchip Technology Inc. REGISTER 19-8: CONFIGURATION REGISTER 6 LOW (CONFIG6L: BYTE ADDRESS 30000Ah) REGISTER 19-9: CONFIGURATION REGISTER 6 HIGH (CONFIG6H: BYTE ADDRESS 30000Bh) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — WRT3(1) WRT2(1) WRT1 WRT0 bit 7 bit 0 bit 7-4 Unimplemented: Read as ‘0’ bit 3 WRT3: Write Protection bit(1) 1 = Block 3 (006000-007FFFh) not write protected 0 = Block 3 (006000-007FFFh) write protected bit 2 WRT2: Write Protection bit(1) 1 = Block 2 (004000-005FFFh) not write protected 0 = Block 2 (004000-005FFFh) write protected bit 1 WRT1: Write Protection bit 1 = Block 1 (002000-003FFFh) not write protected 0 = Block 1 (002000-003FFFh) write protected bit 0 WRT0: Write Protection bit 1 = Block 0 (000200h-001FFFh) not write protected 0 = Block 0 (000200h-001FFFh) write protected Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set. Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state R/C-1 R/C-1 C-1 U-0 U-0 U-0 U-0 U-0 WRTD WRTB WRTC — — — — — bit 7 bit 0 bit 7 WRTD: Data EEPROM Write Protection bit 1 = Data EEPROM not write protected 0 = Data EEPROM write protected bit 6 WRTB: Boot Block Write Protection bit 1 = Boot Block (000000-0001FFh) not write protected 0 = Boot Block (000000-0001FFh) write protected bit 5 WRTC: Configuration Register Write Protection bit 1 = Configuration registers (300000-3000FFh) not write protected 0 = Configuration registers (300000-3000FFh) write protected Note: This bit is read only, and cannot be changed in User mode. bit 4-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit C =Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state© 2006 Microchip Technology Inc. DS39564C-page 201 PIC18FXX2 REGISTER 19-10: CONFIGURATION REGISTER 7 LOW (CONFIG7L: BYTE ADDRESS 30000Ch) REGISTER 19-11: CONFIGURATION REGISTER 7 HIGH (CONFIG7H: BYTE ADDRESS 30000Dh) U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1 — — — — EBTR3(1) EBTR2(1) EBTR1 EBTR0 bit 7 bit 0 bit 7-4 Unimplemented: Read as ‘0’ bit 3 EBTR3: Table Read Protection bit(1) 1 = Block 3 (006000-007FFFh) not protected from Table Reads executed in other blocks 0 = Block 3 (006000-007FFFh) protected from Table Reads executed in other blocks bit 2 EBTR2: Table Read Protection bit(1) 1 = Block 2 (004000-005FFFh) not protected from Table Reads executed in other blocks 0 = Block 2 (004000-005FFFh) protected from Table Reads executed in other blocks bit 1 EBTR1: Table Read Protection bit 1 = Block 1 (002000-003FFFh) not protected from Table Reads executed in other blocks 0 = Block 1 (002000-003FFFh) protected from Table Reads executed in other blocks bit 0 EBTR0: Table Read Protection bit 1 = Block 0 (000200h-001FFFh) not protected from Table Reads executed in other blocks 0 = Block 0 (000200h-001FFFh) protected from Table Reads executed in other blocks Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set. Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state U-0 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 — EBTRB — — — — — — bit 7 bit 0 bit 7 Unimplemented: Read as ‘0’ bit 6 EBTRB: Boot Block Table Read Protection bit 1 = Boot Block (000000-0001FFh) not protected from Table Reads executed in other blocks 0 = Boot Block (000000-0001FFh) protected from Table Reads executed in other blocks bit 5-0 Unimplemented: Read as ‘0’ Legend: R = Readable bit C =Clearable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed statePIC18FXX2 DS39564C-page 202 © 2006 Microchip Technology Inc. REGISTER 19-12: DEVICE ID REGISTER 1 FOR PIC18FXX2 (DEVID1: BYTE ADDRESS 3FFFFEh) REGISTER 19-13: DEVICE ID REGISTER 2 FOR PIC18FXX2 (DEVID2: BYTE ADDRESS 3FFFFFh) RRRRRRRR DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 bit 7 bit 0 bit 7-5 DEV2:DEV0: Device ID bits 000 = PIC18F252 001 = PIC18F452 100 = PIC18F242 101 = PIC18F442 bit 4-0 REV4:REV0: Revision ID bits These bits are used to indicate the device revision. Legend: R = Readable bit P =Programmable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state RRRRRRRR DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 bit 7 bit 0 bit 7-0 DEV10:DEV3: Device ID bits These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the part number. Legend: R = Readable bit P =Programmable bit U = Unimplemented bit, read as ‘0’ - n = Value when device is unprogrammed u = Unchanged from programmed state© 2006 Microchip Technology Inc. DS39564C-page 203 PIC18FXX2 19.2 Watchdog Timer (WDT) The Watchdog Timer is a free running on-chip RC oscillator, which does not require any external components. This RC oscillator is separate from the RC oscillator of the OSC1/CLKI pin. That means that the WDT will run, even if the clock on the OSC1/CLKI and OSC2/CLKO/ RA6 pins of the device has been stopped, for example, by execution of a SLEEP instruction. During normal operation, a WDT time-out generates a device RESET (Watchdog Timer Reset). If the device is in SLEEP mode, a WDT time-out causes the device to wake-up and continue with normal operation (Watchdog Timer Wake-up). The TO bit in the RCON register will be cleared upon a WDT time-out. The Watchdog Timer is enabled/disabled by a device configuration bit. If the WDT is enabled, software execution may not disable this function. When the WDTEN configuration bit is cleared, the SWDTEN bit enables/ disables the operation of the WDT. The WDT time-out period values may be found in the Electrical Specifications (Section 22.0) under parameter D031. Values for the WDT postscaler may be assigned using the configuration bits. 19.2.1 CONTROL REGISTER Register 19-14 shows the WDTCON register. This is a readable and writable register, which contains a control bit that allows software to override the WDT enable configuration bit, only when the configuration bit has disabled the WDT. REGISTER 19-14: WDTCON REGISTER Note: The CLRWDT and SLEEP instructions clear the WDT and the postscaler, if assigned to the WDT and prevent it from timing out and generating a device RESET condition. Note: When a CLRWDT instruction is executed and the postscaler is assigned to the WDT, the postscaler count will be cleared, but the postscaler assignment is not changed. U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 — — — — — — — SWDTEN bit 7 bit 0 bit 7-1 Unimplemented: Read as ’0’ bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit 1 = Watchdog Timer is on 0 = Watchdog Timer is turned off if the WDTEN configuration bit in the configuration register = ‘0’ Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at PORPIC18FXX2 DS39564C-page 204 © 2006 Microchip Technology Inc. 19.2.2 WDT POSTSCALER The WDT has a postscaler that can extend the WDT Reset period. The postscaler is selected at the time of the device programming, by the value written to the CONFIG2H configuration register. FIGURE 19-1: WATCHDOG TIMER BLOCK DIAGRAM TABLE 19-2: SUMMARY OF WATCHDOG TIMER REGISTERS WDT Timer Postscaler WDTEN 8 - to - 1 MUX WDTPS2:WDTPS0 WDT Time-out 8 SWDTEN bit Configuration bit Note: WDPS2:WDPS0 are bits in register CONFIG2H. Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 CONFIG2H — — — — WDTPS2 WDTPS2 WDTPS0 WDTEN RCON IPEN — — RI TO PD POR BOR WDTCON — — — — — — — SWDTEN Legend: Shaded cells are not used by the Watchdog Timer.© 2006 Microchip Technology Inc. DS39564C-page 205 PIC18FXX2 19.3 Power-down Mode (SLEEP) Power-down mode is entered by executing a SLEEP instruction. If enabled, the Watchdog Timer will be cleared, but keeps running, the PD bit (RCON<3>) is cleared, the TO (RCON<4>) bit is set, and the oscillator driver is turned off. The I/O ports maintain the status they had before the SLEEP instruction was executed (driving high, low or hi-impedance). For lowest current consumption in this mode, place all I/O pins at either VDD or VSS, ensure no external circuitry is drawing current from the I/O pin, power-down the A/D and disable external clocks. Pull all I/O pins that are hi-impedance inputs, high or low externally, to avoid switching currents caused by floating inputs. The T0CKI input should also be at VDD or VSS for lowest current consumption. The contribution from on-chip pull-ups on PORTB should be considered. The MCLR pin must be at a logic high level (VIHMC). 19.3.1 WAKE-UP FROM SLEEP The device can wake-up from SLEEP through one of the following events: 1. External RESET input on MCLR pin. 2. Watchdog Timer Wake-up (if WDT was enabled). 3. Interrupt from INT pin, RB port change or a Peripheral Interrupt. The following peripheral interrupts can wake the device from SLEEP: 1. PSP read or write. 2. TMR1 interrupt. Timer1 must be operating as an asynchronous counter. 3. TMR3 interrupt. Timer3 must be operating as an asynchronous counter. 4. CCP Capture mode interrupt. 5. Special event trigger (Timer1 in Asynchronous mode using an external clock). 6. MSSP (START/STOP) bit detect interrupt. 7. MSSP transmit or receive in Slave mode (SPI/I2C). 8. USART RX or TX (Synchronous Slave mode). 9. A/D conversion (when A/D clock source is RC). 10. EEPROM write operation complete. 11. LVD interrupt. Other peripherals cannot generate interrupts, since during SLEEP, no on-chip clocks are present. External MCLR Reset will cause a device RESET. All other events are considered a continuation of program execution and will cause a “wake-up”. The TO and PD bits in the RCON register can be used to determine the cause of the device RESET. The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The TO bit is cleared, if a WDT time-out occurred (and caused wake-up). When the SLEEP instruction is being executed, the next instruction (PC + 2) is pre-fetched. For the device to wake-up through an interrupt event, the corresponding interrupt enable bit must be set (enabled). Wake-up is regardless of the state of the GIE bit. If the GIE bit is clear (disabled), the device continues execution at the instruction after the SLEEP instruction. If the GIE bit is set (enabled), the device executes the instruction after the SLEEP instruction and then branches to the interrupt address. In cases where the execution of the instruction following SLEEP is not desirable, the user should have a NOP after the SLEEP instruction. 19.3.2 WAKE-UP USING INTERRUPTS When global interrupts are disabled (GIE cleared) and any interrupt source has both its interrupt enable bit and interrupt flag bit set, one of the following will occur: • If an interrupt condition (interrupt flag bit and interrupt enable bits are set) occurs before the execution of a SLEEP instruction, the SLEEP instruction will complete as a NOP. Therefore, the WDT and WDT postscaler will not be cleared, the TO bit will not be set and PD bits will not be cleared. • If the interrupt condition occurs during or after the execution of a SLEEP instruction, the device will immediately wake-up from SLEEP. The SLEEP instruction will be completely executed before the wake-up. Therefore, the WDT and WDT postscaler will be cleared, the TO bit will be set and the PD bit will be cleared. Even if the flag bits were checked before executing a SLEEP instruction, it may be possible for flag bits to become set before the SLEEP instruction completes. To determine whether a SLEEP instruction executed, test the PD bit. If the PD bit is set, the SLEEP instruction was executed as a NOP. To ensure that the WDT is cleared, a CLRWDT instruction should be executed before a SLEEP instruction.PIC18FXX2 DS39564C-page 206 © 2006 Microchip Technology Inc. FIGURE 19-2: WAKE-UP FROM SLEEP THROUGH INTERRUPT(1,2) Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 CLKO(4) INT pin INTF flag (INTCON<1>) GIEH bit (INTCON<7>) INSTRUCTION FLOW PC Instruction Fetched Instruction Executed PC PC+2 PC+4 Inst(PC) = SLEEP Inst(PC - 1) Inst(PC + 2) SLEEP Processor in SLEEP Interrupt Latency(3) Inst(PC + 4) Inst(PC + 2) Inst(0008h) Inst(000Ah) Dummy Cycle Inst(0008h) PC + 4 0008h 000Ah Dummy Cycle TOST(2) PC+4 Note 1: XT, HS or LP Oscillator mode assumed. 2: GIE = '1' assumed. In this case, after wake-up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line. 3: TOST = 1024 TOSC (drawing not to scale). This delay will not occur for RC and EC Osc modes. 4: CLKO is not available in these Osc modes, but shown here for timing reference.© 2006 Microchip Technology Inc. DS39564C-page 207 PIC18FXX2 19.4 Program Verification and Code Protection The overall structure of the code protection on the PIC18 FLASH devices differs significantly from other PICmicro devices. The user program memory is divided into five blocks. One of these is a boot block of 512 bytes. The remainder of the memory is divided into four blocks on binary boundaries. Each of the five blocks has three code protection bits associated with them. They are: • Code Protect bit (CPn) • Write Protect bit (WRTn) • External Block Table Read bit (EBTRn) Figure 19-3 shows the program memory organization for 16- and 32-Kbyte devices, and the specific code protection bit associated with each block. The actual locations of the bits are summarized in Table 19-3. FIGURE 19-3: CODE PROTECTED PROGRAM MEMORY FOR PIC18F2XX/4XX TABLE 19-3: SUMMARY OF CODE PROTECTION REGISTERS MEMORY SIZE/DEVICE Block Code Protection 16 Kbytes Controlled By: (PIC18FX42) 32 Kbytes (PIC18FX52) Address Range Boot Block Boot Block 000000h 0001FFh CPB, WRTB, EBTRB Block 0 Block 0 000200h 001FFFh CP0, WRT0, EBTR0 Block 1 Block 1 002000h 003FFFh CP1, WRT1, EBTR1 Unimplemented Read 0’s Block 2 004000h 005FFFh CP2, WRT2, EBTR2 Unimplemented Read 0’s Block 3 006000h 007FFFh CP3, WRT3, EBTR3 Unimplemented Read 0’s Unimplemented Read 0’s 008000h 1FFFFFh (Unimplemented Memory Space) File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 300008h CONFIG5L — — — — CP3 CP2 CP1 CP0 300009h CONFIG5H CPD CPB — — — — — — 30000Ah CONFIG6L — — — — WRT3 WRT2 WRT1 WRT0 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 30000Ch CONFIG7L — — — — EBTR3 EBTR2 EBTR1 EBTR0 30000Dh CONFIG7H — EBTRB — — — — — — Legend: Shaded cells are unimplemented.PIC18FXX2 DS39564C-page 208 © 2006 Microchip Technology Inc. 19.4.1 PROGRAM MEMORY CODE PROTECTION The user memory may be read to or written from any location using the Table Read and Table Write instructions. The device ID may be read with Table Reads. The configuration registers may be read and written with the Table Read and Table Write instructions. In User mode, the CPn bits have no direct effect. CPn bits inhibit external reads and writes. A block of user memory may be protected from Table Writes if the WRTn configuration bit is ‘0’. The EBTRn bits control Table Reads. For a block of user memory with the EBTRn bit set to ‘0’, a Table Read instruction that executes from within that block is allowed to read. A Table Read instruction that executes from a location outside of that block is not allowed to read, and will result in reading ‘0’s. Figures 19-4 through 19-6 illustrate Table Write and Table Read protection. FIGURE 19-4: TABLE WRITE (WRTn) DISALLOWED Note: Code protection bits may only be written to a ‘0’ from a ‘1’ state. It is not possible to write a ‘1’ to a bit in the ‘0’ state. Code protection bits are only set to ‘1’ by a full chip erase or block erase function. The full chip erase and block erase functions can only be initiated via ICSP or an external programmer. 000000h 0001FFh 000200h 001FFFh 002000h 003FFFh 004000h 005FFFh 006000h 007FFFh WRTB,EBTRB = 11 WRT0,EBTR0 = 01 WRT1,EBTR1 = 11 WRT2,EBTR2 = 11 WRT3,EBTR3 = 11 TBLWT * TBLPTR = 000FFF PC = 001FFE PC = 004FFE TBLWT * Register Values Program Memory Configuration Bit Settings Results: All Table Writes disabled to Blockn whenever WRTn = ‘0’.© 2006 Microchip Technology Inc. DS39564C-page 209 PIC18FXX2 FIGURE 19-5: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED FIGURE 19-6: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED 000000h 0001FFh 000200h 001FFFh 002000h 003FFFh 004000h 005FFFh 006000h 007FFFh WRTB,EBTRB = 11 WRT0,EBTR0 = 10 WRT1,EBTR1 = 11 WRT2,EBTR2 = 11 WRT3,EBTR3 = 11 TBLRD * TBLPTR = 000FFF PC = 002FFE Results: All Table Reads from external blocks to Blockn are disabled whenever EBTRn = ‘0’. TABLAT register returns a value of “0”. Register Values Program Memory Configuration Bit Settings 000000h 0001FFh 000200h 001FFFh 002000h 003FFFh 004000h 005FFFh 006000h 007FFFh WRTB,EBTRB = 11 WRT0,EBTR0 = 10 WRT1,EBTR1 = 11 WRT2,EBTR2 = 11 WRT3,EBTR3 = 11 TBLRD * TBLPTR = 000FFF PC = 001FFE Register Values Program Memory Configuration Bit Settings Results: Table Reads permitted within Blockn, even when EBTRBn = ‘0’. TABLAT register returns the value of the data at the location TBLPTR.PIC18FXX2 DS39564C-page 210 © 2006 Microchip Technology Inc. 19.4.2 DATA EEPROM CODE PROTECTION The entire Data EEPROM is protected from external reads and writes by two bits: CPD and WRTD. CPD inhibits external reads and writes of Data EEPROM. WRTD inhibits external writes to Data EEPROM. The CPU can continue to read and write Data EEPROM regardless of the protection bit settings. 19.4.3 CONFIGURATION REGISTER PROTECTION The configuration registers can be write protected. The WRTC bit controls protection of the configuration registers. In User mode, the WRTC bit is readable only. WRTC can only be written via ICSP or an external programmer. 19.5 ID Locations Eight memory locations (200000h - 200007h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are accessible during normal execution through the TBLRD and TBLWT instructions, or during program/verify. The ID locations can be read when the device is code protected. The sequence for programming the ID locations is similar to programming the FLASH memory (see Section 5.5.1). 19.6 In-Circuit Serial Programming PIC18FXXX microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data, and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices, and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed. 19.7 In-Circuit Debugger When the DEBUG bit in configuration register CONFIG4L is programmed to a '0', the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB® IDE. When the microcontroller has this feature enabled, some of the resources are not available for general use. Table 19-4 shows which features are consumed by the background debugger. TABLE 19-4: DEBUGGER RESOURCES To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to MCLR/VPP, VDD, GND, RB7 and RB6. This will interface to the In-Circuit Debugger module available from Microchip or one of the third party development tool companies. 19.8 Low Voltage ICSP Programming The LVP bit configuration register CONFIG4L enables low voltage ICSP programming. This mode allows the microcontroller to be programmed via ICSP using a VDD source in the operating voltage range. This only means that VPP does not have to be brought to VIHH, but can instead be left at the normal operating voltage. In this mode, the RB5/PGM pin is dedicated to the programming function and ceases to be a general purpose I/O pin. During programming, VDD is applied to the MCLR/VPP pin. To enter Programming mode, VDD must be applied to the RB5/PGM, provided the LVP bit is set. The LVP bit defaults to a (‘1’) from the factory. If Low Voltage Programming mode is not used, the LVP bit can be programmed to a '0' and RB5/PGM becomes a digital I/O pin. However, the LVP bit may only be programmed when programming is entered with VIHH on MCLR/VPP. It should be noted that once the LVP bit is programmed to 0, only the High Voltage Programming mode is available and only High Voltage Programming mode can be used to program the device. When using low voltage ICSP, the part must be supplied 4.5V to 5.5V, if a bulk erase will be executed. This includes reprogramming of the code protect bits from an on-state to off-state. For all other cases of low voltage ICSP, the part may be programmed at the normal operating voltage. This means unique user IDs, or user code can be reprogrammed or added. I/O pins RB6, RB7 Stack 2 levels Program Memory 512 bytes Data Memory 10 bytes Note 1: The High Voltage Programming mode is always available, regardless of the state of the LVP bit, by applying VIHH to the MCLR pin. 2: While in low voltage ICSP mode, the RB5 pin can no longer be used as a general purpose I/O pin, and should be held low during normal operation to protect against inadvertent ICSP mode entry. 3: When using low voltage ICSP programming (LVP), the pull-up on RB5 becomes disabled. If TRISB bit 5 is cleared, thereby setting RB5 as an output, LATB bit 5 must also be cleared for proper operation.© 2006 Microchip Technology Inc. DS39564C-page 211 PIC18FXX2 20.0 INSTRUCTION SET SUMMARY The PIC18FXXX instruction set adds many enhancements to the previous PICmicro instruction sets, while maintaining an easy migration from these PICmicro instruction sets. Most instructions are a single program memory word (16-bits), but there are three instructions that require two program memory locations. Each single word instruction is a 16-bit word divided into an OPCODE, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. The instruction set is highly orthogonal and is grouped into four basic categories: • Byte-oriented operations • Bit-oriented operations • Literal operations • Control operations The PIC18FXXX instruction set summary in Table 20-2 lists byte-oriented, bit-oriented, literal and control operations. Table 20-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. The file register (specified by ‘f’) 2. The destination of the result (specified by ‘d’) 3. The accessed memory (specified by ‘a’) The file register designator 'f' specifies which file register is to be used by the instruction. The destination designator ‘d’ specifies where the result of the operation is to be placed. If 'd' is zero, the result is placed in the WREG register. If 'd' is one, the result is placed in the file register specified in the instruction. All bit-oriented instructions have three operands: 1. The file register (specified by ‘f’) 2. The bit in the file register (specified by ‘b’) 3. The accessed memory (specified by ‘a’) The bit field designator 'b' selects the number of the bit affected by the operation, while the file register designator 'f' represents the number of the file in which the bit is located. The literal instructions may use some of the following operands: • A literal value to be loaded into a file register (specified by ‘k’) • The desired FSR register to load the literal value into (specified by ‘f’) • No operand required (specified by ‘—’) The control instructions may use some of the following operands: • A program memory address (specified by ‘n’) • The mode of the Call or Return instructions (specified by ‘s’) • The mode of the Table Read and Table Write instructions (specified by ‘m’) • No operand required (specified by ‘—’) All instructions are a single word, except for three double-word instructions. These three instructions were made double-word instructions so that all the required information is available in these 32 bits. In the second word, the 4-MSbs are 1’s. If this second word is executed as an instruction (by itself), it will execute as a NOP. All single word instructions are executed in a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruction. In these cases, the execution takes two instruction cycles with the additional instruction cycle(s) executed as a NOP. The double-word instructions execute in two instruction cycles. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 μs. If a conditional test is true or the program counter is changed as a result of an instruction, the instruction execution time is 2 μs. Two-word branch instructions (if true) would take 3 μs. Figure 20-1 shows the general formats that the instructions can have. All examples use the format ‘nnh’ to represent a hexadecimal number, where ‘h’ signifies a hexadecimal digit. The Instruction Set Summary, shown in Table 20-2, lists the instructions recognized by the Microchip Assembler (MPASMTM). Section 20.1 provides a description of each instruction.PIC18FXX2 DS39564C-page 212 © 2006 Microchip Technology Inc. TABLE 20-1: OPCODE FIELD DESCRIPTIONS Field Description a RAM access bit a = 0: RAM location in Access RAM (BSR register is ignored) a = 1: RAM bank is specified by BSR register bbb Bit address within an 8-bit file register (0 to 7) BSR Bank Select Register. Used to select the current RAM bank. d Destination select bit; d = 0: store result in WREG, d = 1: store result in file register f. dest Destination either the WREG register or the specified register file location f 8-bit Register file address (0x00 to 0xFF) fs 12-bit Register file address (0x000 to 0xFFF). This is the source address. fd 12-bit Register file address (0x000 to 0xFFF). This is the destination address. k Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value) label Label name mm The mode of the TBLPTR register for the Table Read and Table Write instructions. Only used with Table Read and Table Write instructions: * No Change to register (such as TBLPTR with Table reads and writes) *+ Post-Increment register (such as TBLPTR with Table reads and writes) *- Post-Decrement register (such as TBLPTR with Table reads and writes) +* Pre-Increment register (such as TBLPTR with Table reads and writes) n The relative address (2’s complement number) for relative branch instructions, or the direct address for Call/Branch and Return instructions PRODH Product of Multiply high byte PRODL Product of Multiply low byte s Fast Call/Return mode select bit. s = 0: do not update into/from shadow registers s = 1: certain registers loaded into/from shadow registers (Fast mode) u Unused or Unchanged WREG Working register (accumulator) x Don't care (0 or 1) The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. TBLPTR 21-bit Table Pointer (points to a Program Memory location) TABLAT 8-bit Table Latch TOS Top-of-Stack PC Program Counter PCL Program Counter Low Byte PCH Program Counter High Byte PCLATH Program Counter High Byte Latch PCLATU Program Counter Upper Byte Latch GIE Global Interrupt Enable bit WDT Watchdog Timer TO Time-out bit PD Power-down bit C, DC, Z, OV, N ALU status bits Carry, Digit Carry, Zero, Overflow, Negative [ ] Optional ( ) Contents → Assigned to < > Register bit field ∈ In the set of italics User defined term (font is courier)© 2006 Microchip Technology Inc. DS39564C-page 213 PIC18FXX2 FIGURE 20-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 15 10 9 8 7 0 d = 0 for result destination to be WREG register OPCODE d a f (FILE #) d = 1 for result destination to be file register (f) a = 0 to force Access Bank Bit-oriented file register operations 15 12 11 9 8 7 0 OPCODE b (BIT #) a f (FILE #) b = 3-bit position of bit in file register (f) Literal operations 15 8 7 0 OPCODE k (literal) k = 8-bit immediate value Byte to Byte move operations (2-word) 15 12 11 0 OPCODE f (Source FILE #) CALL, GOTO and Branch operations 15 8 7 0 OPCODE n<7:0> (literal) n = 20-bit immediate value a = 1 for BSR to select bank f = 8-bit file register address a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address 15 12 11 0 1111 n<19:8> (literal) 15 12 11 0 1111 f (Destination FILE #) f = 12-bit file register address Control operations Example Instruction ADDWF MYREG, W, B MOVFF MYREG1, MYREG2 BSF MYREG, bit, B MOVLW 0x7F GOTO Label 15 8 7 0 OPCODE n<7:0> (literal) 15 12 11 0 n<19:8> (literal) CALL MYFUNC 15 11 10 0 OPCODE n<10:0> (literal) S = Fast bit BRA MYFUNC 15 8 7 0 OPCODE n<7:0> (literal) BC MYFUNC SPIC18FXX2 DS39564C-page 214 © 2006 Microchip Technology Inc. TABLE 20-2: PIC18FXXX INSTRUCTION SET Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB SUBWF SUBWFB SWAPF TSTFSZ XORWF f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a fs, fd f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a Add WREG and f Add WREG and Carry bit to f AND WREG with f Clear f Complement f Compare f with WREG, skip = Compare f with WREG, skip > Compare f with WREG, skip < Decrement f Decrement f, Skip if 0 Decrement f, Skip if Not 0 Increment f Increment f, Skip if 0 Increment f, Skip if Not 0 Inclusive OR WREG with f Move f Move fs (source) to 1st word fd (destination) 2nd word Move WREG to f Multiply WREG with f Negate f Rotate Left f through Carry Rotate Left f (No Carry) Rotate Right f through Carry Rotate Right f (No Carry) Set f Subtract f from WREG with borrow Subtract WREG from f Subtract WREG from f with borrow Swap nibbles in f Test f, skip if 0 Exclusive OR WREG with f 1 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 (2 or 3) 1 0010 0010 0001 0110 0001 0110 0110 0110 0000 0010 0100 0010 0011 0100 0001 0101 1100 1111 0110 0000 0110 0011 0100 0011 0100 0110 0101 0101 0101 0011 0110 0001 01da0 0da 01da 101a 11da 001a 010a 000a 01da 11da 11da 10da 11da 10da 00da 00da ffff ffff 111a 001a 110a 01da 01da 00da 00da 100a 01da 11da 10da 10da 011a 10da ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None None None C, DC, Z, OV, N C, Z, N Z, N C, Z, N Z, N None C, DC, Z, OV, N C, DC, Z, OV, N C, DC, Z, OV, N None None Z, N 1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1 1, 2 1, 2 1, 2 1, 2 4 1, 2 BIT-ORIENTED FILE REGISTER OPERATIONS BCF BSF BTFSC BTFSS BTG f, b, a f, b, a f, b, a f, b, a f, d, a Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set Bit Toggle f 1 1 1 (2 or 3) 1 (2 or 3) 1 1001 1000 1011 1010 0111 bbba bbba bbba bbba bbba ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff None None None None None 1, 2 1, 2 3, 4 3, 4 1, 2 Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.© 2006 Microchip Technology Inc. DS39564C-page 215 PIC18FXX2 CONTROL OPERATIONS BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL CLRWDT DAW GOTO NOP NOP POP PUSH RCALL RESET RETFIE RETLW RETURN SLEEP n n n n n n n n n n, s — — n — — — — n s k s — Branch if Carry Branch if Negative Branch if Not Carry Branch if Not Negative Branch if Not Overflow Branch if Not Zero Branch if Overflow Branch Unconditionally Branch if Zero Call subroutine1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to address1st word 2nd word No Operation No Operation Pop top of return stack (TOS) Push top of return stack (TOS) Relative Call Software device RESET Return from interrupt enable Return with literal in WREG Return from Subroutine Go into Standby mode 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 1 (2) 1 (2) 2 1 1 2 1 1 1 1 2 1 2 2 2 1 1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 0000 0000 0000 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 1100 0000 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 kkkk 0001 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s kkkk 001s 0011 None None None None None None None None None None TO, PD C None None None None None None All GIE/GIEH, PEIE/GIEL None None TO, PD 4 TABLE 20-2: PIC18FXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.PIC18FXX2 DS39564C-page 216 © 2006 Microchip Technology Inc. LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR MOVLB MOVLW MULLW RETLW SUBLW XORLW k k k f, k k k k k k k Add literal and WREG AND literal with WREG Inclusive OR literal with WREG Move literal (12-bit) 2nd word to FSRx 1st word Move literal to BSR<3:0> Move literal to WREG Multiply literal with WREG Return with literal in WREG Subtract WREG from literal Exclusive OR literal with WREG 1 1 1 2 1 1 1 2 1 1 0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk C, DC, Z, OV, N Z, N Z, N None None None None None C, DC, Z, OV, N Z, N DATA MEMORY ↔ PROGRAM MEMORY OPERATIONS TBLRD* TBLRD*+ TBLRD*- TBLRD+* TBLWT* TBLWT*+ TBLWT*- TBLWT+* Table Read Table Read with post-increment Table Read with post-decrement Table Read with pre-increment Table Write Table Write with post-increment Table Write with post-decrement Table Write with pre-increment 2 2 (5) 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 1001 1010 1011 1100 1101 1110 1111 None None None None None None None None TABLE 20-2: PIC18FXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word Status Affected Notes MSb LSb Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.© 2006 Microchip Technology Inc. DS39564C-page 217 PIC18FXX2 20.1 Instruction Set ADDLW ADD literal to W Syntax: [ label ] ADDLW k Operands: 0 ≤ k ≤ 255 Operation: (W) + k → W Status Affected: N, OV, C, DC, Z Encoding: 0000 1111 kkkk kkkk Description: The contents of W are added to the 8-bit literal 'k' and the result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to W Example: ADDLW 0x15 Before Instruction W = 0x10 After Instruction W = 0x25 ADDWF ADD W to f Syntax: [ label ] ADDWF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) + (f) → dest Status Affected: N, OV, C, DC, Z Encoding: 0010 01da ffff ffff Description: Add W to register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If ‘a’ is 0, the Access Bank will be selected. If ‘a’ is 1, the BSR is used. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: ADDWF REG, 0, 0 Before Instruction W = 0x17 REG = 0xC2 After Instruction W = 0xD9 REG = 0xC2PIC18FXX2 DS39564C-page 218 © 2006 Microchip Technology Inc. ADDWFC ADD W and Carry bit to f Syntax: [ label ] ADDWFC f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) + (f) + (C) → dest Status Affected: N,OV, C, DC, Z Encoding: 0010 00da ffff ffff Description: Add W, the Carry Flag and data memory location 'f'. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed in data memory location 'f'. If ‘a’ is 0, the Access Bank will be selected. If ‘a’ is 1, the BSR will not be overridden. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: ADDWFC REG, 0, 1 Before Instruction Carry bit = 1 REG = 0x02 W = 0x4D After Instruction Carry bit = 0 REG = 0x02 W = 0x50 ANDLW AND literal with W Syntax: [ label ] ANDLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .AND. k → W Status Affected: N,Z Encoding: 0000 1011 kkkk kkkk Description: The contents of W are ANDed with the 8-bit literal 'k'. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to W Example: ANDLW 0x5F Before Instruction W = 0xA3 After Instruction W = 0x03© 2006 Microchip Technology Inc. DS39564C-page 219 PIC18FXX2 ANDWF AND W with f Syntax: [ label ] ANDWF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .AND. (f) → dest Status Affected: N,Z Encoding: 0001 01da ffff ffff Description: The contents of W are AND’ed with register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If ‘a’ is 0, the Access Bank will be selected. If ‘a’ is 1, the BSR will not be overridden (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: ANDWF REG, 0, 0 Before Instruction W = 0x17 REG = 0xC2 After Instruction W = 0x02 REG = 0xC2 BC Branch if Carry Syntax: [ label ] BC n Operands: -128 ≤ n ≤ 127 Operation: if carry bit is ’1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0010 nnnn nnnn Description: If the Carry bit is ’1’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BC 5 Before Instruction PC = address (HERE) After Instruction If Carry = 1; PC = address (HERE+12) If Carry = 0; PC = address (HERE+2)PIC18FXX2 DS39564C-page 220 © 2006 Microchip Technology Inc. BCF Bit Clear f Syntax: [ label ] BCF f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: 0 → f Status Affected: None Encoding: 1001 bbba ffff ffff Description: Bit 'b' in register 'f' is cleared. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: BCF FLAG_REG, 7, 0 Before Instruction FLAG_REG = 0xC7 After Instruction FLAG_REG = 0x47 BN Branch if Negative Syntax: [ label ] BN n Operands: -128 ≤ n ≤ 127 Operation: if negative bit is ’1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0110 nnnn nnnn Description: If the Negative bit is ’1’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BN Jump Before Instruction PC = address (HERE) After Instruction If Negative = 1; PC = address (Jump) If Negative = 0; PC = address (HERE+2)© 2006 Microchip Technology Inc. DS39564C-page 221 PIC18FXX2 BNC Branch if Not Carry Syntax: [ label ] BNC n Operands: -128 ≤ n ≤ 127 Operation: if carry bit is ’0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0011 nnnn nnnn Description: If the Carry bit is ’0’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BNC Jump Before Instruction PC = address (HERE) After Instruction If Carry = 0; PC = address (Jump) If Carry = 1; PC = address (HERE+2) BNN Branch if Not Negative Syntax: [ label ] BNN n Operands: -128 ≤ n ≤ 127 Operation: if negative bit is ’0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0111 nnnn nnnn Description: If the Negative bit is ’0’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BNN Jump Before Instruction PC = address (HERE) After Instruction If Negative = 0; PC = address (Jump) If Negative = 1; PC = address (HERE+2)PIC18FXX2 DS39564C-page 222 © 2006 Microchip Technology Inc. BNOV Branch if Not Overflow Syntax: [ label ] BNOV n Operands: -128 ≤ n ≤ 127 Operation: if overflow bit is ’0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0101 nnnn nnnn Description: If the Overflow bit is ’0’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BNOV Jump Before Instruction PC = address (HERE) After Instruction If Overflow = 0; PC = address (Jump) If Overflow = 1; PC = address (HERE+2) BNZ Branch if Not Zero Syntax: [ label ] BNZ n Operands: -128 ≤ n ≤ 127 Operation: if zero bit is ’0’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0001 nnnn nnnn Description: If the Zero bit is ’0’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BNZ Jump Before Instruction PC = address (HERE) After Instruction If Zero = 0; PC = address (Jump) If Zero = 1; PC = address (HERE+2)© 2006 Microchip Technology Inc. DS39564C-page 223 PIC18FXX2 BRA Unconditional Branch Syntax: [ label ] BRA n Operands: -1024 ≤ n ≤ 1023 Operation: (PC) + 2 + 2n → PC Status Affected: None Encoding: 1101 0nnn nnnn nnnn Description: Add the 2’s complement number ’2n’ to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation Example: HERE BRA Jump Before Instruction PC = address (HERE) After Instruction PC = address (Jump) BSF Bit Set f Syntax: [ label ] BSF f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: 1 → f Status Affected: None Encoding: 1000 bbba ffff ffff Description: Bit 'b' in register 'f' is set. If ‘a’ is 0 Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: BSF FLAG_REG, 7, 1 Before Instruction FLAG_REG = 0x0A After Instruction FLAG_REG = 0x8APIC18FXX2 DS39564C-page 224 © 2006 Microchip Technology Inc. BTFSC Bit Test File, Skip if Clear Syntax: [ label ] BTFSC f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: skip if (f) = 0 Status Affected: None Encoding: 1011 bbba ffff ffff Description: If bit 'b' in register ’f' is 0, then the next instruction is skipped. If bit 'b' is 0, then the next instruction fetched during the current instruction execution is discarded, and a NOP is executed instead, making this a twocycle instruction. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSC : : FLAG, 1, 0 Before Instruction PC = address (HERE) After Instruction If FLAG<1> = 0; PC = address (TRUE) If FLAG<1> = 1; PC = address (FALSE) BTFSS Bit Test File, Skip if Set Syntax: [ label ] BTFSS f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: skip if (f) = 1 Status Affected: None Encoding: 1010 bbba ffff ffff Description: If bit 'b' in register 'f' is 1, then the next instruction is skipped. If bit 'b' is 1, then the next instruction fetched during the current instruction execution, is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSS : : FLAG, 1, 0 Before Instruction PC = address (HERE) After Instruction If FLAG<1> = 0; PC = address (FALSE) If FLAG<1> = 1; PC = address (TRUE)© 2006 Microchip Technology Inc. DS39564C-page 225 PIC18FXX2 BTG Bit Toggle f Syntax: [ label ] BTG f,b[,a] Operands: 0 ≤ f ≤ 255 0 ≤ b ≤ 7 a ∈ [0,1] Operation: (f) → f Status Affected: None Encoding: 0111 bbba ffff ffff Description: Bit 'b' in data memory location 'f' is inverted. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: BTG PORTC, 4, 0 Before Instruction: PORTC = 0111 0101 [0x75] After Instruction: PORTC = 0110 0101 [0x65] BOV Branch if Overflow Syntax: [ label ] BOV n Operands: -128 ≤ n ≤ 127 Operation: if overflow bit is ’1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0100 nnnn nnnn Description: If the Overflow bit is ’1’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BOV Jump Before Instruction PC = address (HERE) After Instruction If Overflow = 1; PC = address (Jump) If Overflow = 0; PC = address (HERE+2)PIC18FXX2 DS39564C-page 226 © 2006 Microchip Technology Inc. BZ Branch if Zero Syntax: [ label ] BZ n Operands: -128 ≤ n ≤ 127 Operation: if Zero bit is ’1’ (PC) + 2 + 2n → PC Status Affected: None Encoding: 1110 0000 nnnn nnnn Description: If the Zero bit is ’1’, then the program will branch. The 2’s complement number ’2n’ is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal 'n' Process Data No operation Example: HERE BZ Jump Before Instruction PC = address (HERE) After Instruction If Zero = 1; PC = address (Jump) If Zero = 0; PC = address (HERE+2) CALL Subroutine Call Syntax: [ label ] CALL k [,s] Operands: 0 ≤ k ≤ 1048575 s ∈ [0,1] Operation: (PC) + 4 → TOS, k → PC<20:1>, if s = 1 (W) → WS, (STATUS) → STATUSS, (BSR) → BSRS Status Affected: None Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 110s k19kkk k7kkk kkkk kkkk0 kkkk8 Description: Subroutine call of entire 2 Mbyte memory range. First, return address (PC+ 4) is pushed onto the return stack. If ’s’ = 1, the W, STATUS and BSR registers are also pushed into their respective shadow registers, WS, STATUSS and BSRS. If 's' = 0, no update occurs (default). Then, the 20-bit value ’k’ is loaded into PC<20:1>. CALL is a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k'<7:0>, Push PC to stack Read literal ’k’<19:8>, Write to PC No operation No operation No operation No operation Example: HERE CALL THERE,1 Before Instruction PC = address (HERE) After Instruction PC = address (THERE) TOS = address (HERE + 4) WS = W BSRS = BSR STATUSS= STATUS© 2006 Microchip Technology Inc. DS39564C-page 227 PIC18FXX2 CLRF Clear f Syntax: [ label ] CLRF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: 000h → f 1 → Z Status Affected: Z Encoding: 0110 101a ffff ffff Description: Clears the contents of the specified register. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: CLRF FLAG_REG,1 Before Instruction FLAG_REG = 0x5A After Instruction FLAG_REG = 0x00 CLRWDT Clear Watchdog Timer Syntax: [ label ] CLRWDT Operands: None Operation: 000h → WDT, 000h → WDT postscaler, 1 → TO, 1 → PD Status Affected: TO, PD Encoding: 0000 0000 0000 0100 Description: CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits TO and PD are set. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data No operation Example: CLRWDT Before Instruction WDT Counter = ? After Instruction WDT Counter = 0x00 WDT Postscaler = 0 TO = 1 PD = 1PIC18FXX2 DS39564C-page 228 © 2006 Microchip Technology Inc. COMF Complement f Syntax: [ label ] COMF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: → dest Status Affected: N, Z Encoding: 0001 11da ffff ffff Description: The contents of register 'f' are complemented. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: COMF REG, 0, 0 Before Instruction REG = 0x13 After Instruction REG = 0x13 W = 0xEC (f) CPFSEQ Compare f with W, skip if f = W Syntax: [ label ] CPFSEQ f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) = (W) (unsigned comparison) Status Affected: None Encoding: 0110 001a ffff ffff Description: Compares the contents of data memory location 'f' to the contents of W by performing an unsigned subtraction. If 'f' = W, then the fetched instruction is discarded and a NOP is executed instead, making this a twocycle instruction. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSEQ REG, 0 NEQUAL : EQUAL : Before Instruction PC Address = HERE W =? REG = ? After Instruction If REG = W; PC = Address (EQUAL) If REG ≠ W; PC = Address (NEQUAL)© 2006 Microchip Technology Inc. DS39564C-page 229 PIC18FXX2 CPFSGT Compare f with W, skip if f > W Syntax: [ label ] CPFSGT f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) − (W), skip if (f) > (W) (unsigned comparison) Status Affected: None Encoding: 0110 010a ffff ffff Description: Compares the contents of data memory location 'f' to the contents of the W by performing an unsigned subtraction. If the contents of 'f' are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSGT REG, 0 NGREATER : GREATER : Before Instruction PC = Address (HERE) W = ? After Instruction If REG > W; PC = Address (GREATER) If REG ≤ W; PC = Address (NGREATER) CPFSLT Compare f with W, skip if f < W Syntax: [ label ] CPFSLT f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (f) – (W), skip if (f) < (W) (unsigned comparison) Status Affected: None Encoding: 0110 000a ffff ffff Description: Compares the contents of data memory location 'f' to the contents of W by performing an unsigned subtraction. If the contents of 'f' are less than the contents of W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is 0, the Access Bank will be selected. If ’a’ is 1, the BSR will not be overridden (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE CPFSLT REG, 1 NLESS : LESS : Before Instruction PC = Address (HERE) W = ? After Instruction If REG < W; PC = Address (LESS) If REG ≥ W; PC = Address (NLESS)PIC18FXX2 DS39564C-page 230 © 2006 Microchip Technology Inc. DAW Decimal Adjust W Register Syntax: [ label ] DAW Operands: None Operation: If [W<3:0> >9] or [DC = 1] then (W<3:0>) + 6 → W<3:0>; else (W<3:0>) → W<3:0>; If [W<7:4> >9] or [C = 1] then (W<7:4>) + 6 → W<7:4>; else (W<7:4>) → W<7:4>; Status Affected: C Encoding: 0000 0000 0000 0111 Description: DAW adjusts the eight-bit value in W, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register W Process Data Write W Example1: DAW Before Instruction W = 0xA5 C =0 DC = 0 After Instruction W = 0x05 C =1 DC = 0 Example 2: Before Instruction W = 0xCE C =0 DC = 0 After Instruction W = 0x34 C =1 DC = 0 DECF Decrement f Syntax: [ label ] DECF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest Status Affected: C, DC, N, OV, Z Encoding: 0000 01da ffff ffff Description: Decrement register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: DECF CNT, 1, 0 Before Instruction CNT = 0x01 Z =0 After Instruction CNT = 0x00 Z =1© 2006 Microchip Technology Inc. DS39564C-page 231 PIC18FXX2 DECFSZ Decrement f, skip if 0 Syntax: [ label ] DECFSZ f [,d [,a]] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest, skip if result = 0 Status Affected: None Encoding: 0010 11da ffff ffff Description: The contents of register 'f' are decremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If the result is 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a two-cycle instruction. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE DECFSZ CNT, 1, 1 GOTO LOOP CONTINUE Before Instruction PC = Address (HERE) After Instruction CNT = CNT - 1 If CNT = 0; PC = Address (CONTINUE) If CNT ≠ 0; PC = Address (HERE+2) DCFSNZ Decrement f, skip if not 0 Syntax: [ label ] DCFSNZ f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – 1 → dest, skip if result ≠ 0 Status Affected: None Encoding: 0100 11da ffff ffff Description: The contents of register 'f' are decremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If the result is not 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a twocycle instruction. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE DCFSNZ TEMP, 1, 0 ZERO : NZERO : Before Instruction TEMP = ? After Instruction TEMP = TEMP - 1, If TEMP = 0; PC = Address (ZERO) If TEMP ≠ 0; PC = Address (NZERO)PIC18FXX2 DS39564C-page 232 © 2006 Microchip Technology Inc. GOTO Unconditional Branch Syntax: [ label ] GOTO k Operands: 0 ≤ k ≤ 1048575 Operation: k → PC<20:1> Status Affected: None Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8 Description: GOTO allows an unconditional branch anywhere within entire 2 Mbyte memory range. The 20-bit value ’k’ is loaded into PC<20:1>. GOTO is always a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k'<7:0>, No operation Read literal ’k’<19:8>, Write to PC No operation No operation No operation No operation Example: GOTO THERE After Instruction PC = Address (THERE) INCF Increment f Syntax: [ label ] INCF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest Status Affected: C, DC, N, OV, Z Encoding: 0010 10da ffff ffff Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: INCF CNT, 1, 0 Before Instruction CNT = 0xFF Z =0 C =? DC = ? After Instruction CNT = 0x00 Z =1 C =1 DC = 1© 2006 Microchip Technology Inc. DS39564C-page 233 PIC18FXX2 INCFSZ Increment f, skip if 0 Syntax: [ label ] INCFSZ f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest, skip if result = 0 Status Affected: None Encoding: 0011 11da ffff ffff Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f'. (default) If the result is 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a two-cycle instruction. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE INCFSZ CNT, 1, 0 NZERO : ZERO : Before Instruction PC = Address (HERE) After Instruction CNT = CNT + 1 If CNT = 0; PC = Address (ZERO) If CNT ≠ 0; PC = Address (NZERO) INFSNZ Increment f, skip if not 0 Syntax: [ label ] INFSNZ f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) + 1 → dest, skip if result ≠ 0 Status Affected: None Encoding: 0100 10da ffff ffff Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If the result is not 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a twocycle instruction. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE INFSNZ REG, 1, 0 ZERO NZERO Before Instruction PC = Address (HERE) After Instruction REG = REG + 1 If REG ≠ 0; PC = Address (NZERO) If REG = 0; PC = Address (ZERO)PIC18FXX2 DS39564C-page 234 © 2006 Microchip Technology Inc. IORLW Inclusive OR literal with W Syntax: [ label ] IORLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .OR. k → W Status Affected: N, Z Encoding: 0000 1001 kkkk kkkk Description: The contents of W are OR’ed with the eight-bit literal 'k'. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to W Example: IORLW 0x35 Before Instruction W = 0x9A After Instruction W = 0xBF IORWF Inclusive OR W with f Syntax: [ label ] IORWF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .OR. (f) → dest Status Affected: N, Z Encoding: 0001 00da ffff ffff Description: Inclusive OR W with register 'f'. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: IORWF RESULT, 0, 1 Before Instruction RESULT = 0x13 W = 0x91 After Instruction RESULT = 0x13 W = 0x93© 2006 Microchip Technology Inc. DS39564C-page 235 PIC18FXX2 LFSR Load FSR Syntax: [ label ] LFSR f,k Operands: 0 ≤ f ≤ 2 0 ≤ k ≤ 4095 Operation: k → FSRf Status Affected: None Encoding: 1110 1111 1110 0000 00ff k7kkk k11kkk kkkk Description: The 12-bit literal 'k' is loaded into the file select register pointed to by 'f'. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' MSB Process Data Write literal 'k' MSB to FSRfH Decode Read literal 'k' LSB Process Data Write literal 'k' to FSRfL Example: LFSR 2, 0x3AB After Instruction FSR2H = 0x03 FSR2L = 0xAB MOVF Move f Syntax: [ label ] MOVF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: f → dest Status Affected: N, Z Encoding: 0101 00da ffff ffff Description: The contents of register 'f' are moved to a destination dependent upon the status of ’d’. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). Location 'f' can be anywhere in the 256 byte bank. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write W Example: MOVF REG, 0, 0 Before Instruction REG = 0x22 W = 0xFF After Instruction REG = 0x22 W = 0x22PIC18FXX2 DS39564C-page 236 © 2006 Microchip Technology Inc. MOVFF Move f to f Syntax: [ label ] MOVFF fs,fd Operands: 0 ≤ fs ≤ 4095 0 ≤ fd ≤ 4095 Operation: (fs) → fd Status Affected: None Encoding: 1st word (source) 2nd word (destin.) 1100 1111 ffff ffff ffff ffff ffffs ffffd Description: The contents of source register 'fs' are moved to destination register 'fd'. Location of source 'fs' can be anywhere in the 4096 byte data space (000h to FFFh), and location of destination 'fd' can also be anywhere from 000h to FFFh. Either source or destination can be W (a useful special situation). MOVFF is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). The MOVFF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. Note: The MOVFF instruction should not be used to modify interrupt settings while any interrupt is enabled. See Section 8.0 for more information. Words: 2 Cycles: 2 (3) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' (src) Process Data No operation Decode No operation No dummy read No operation Write register 'f' (dest) Example: MOVFF REG1, REG2 Before Instruction REG1 = 0x33 REG2 = 0x11 After Instruction REG1 = 0x33, REG2 = 0x33 MOVLB Move literal to low nibble in BSR Syntax: [ label ] MOVLB k Operands: 0 ≤ k ≤ 255 Operation: k → BSR Status Affected: None Encoding: 0000 0001 kkkk kkkk Description: The 8-bit literal 'k' is loaded into the Bank Select Register (BSR). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write literal 'k' to BSR Example: MOVLB 5 Before Instruction BSR register = 0x02 After Instruction BSR register = 0x05© 2006 Microchip Technology Inc. DS39564C-page 237 PIC18FXX2 MOVLW Move literal to W Syntax: [ label ] MOVLW k Operands: 0 ≤ k ≤ 255 Operation: k → W Status Affected: None Encoding: 0000 1110 kkkk kkkk Description: The eight-bit literal 'k' is loaded into W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to W Example: MOVLW 0x5A After Instruction W = 0x5A MOVWF Move W to f Syntax: [ label ] MOVWF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (W) → f Status Affected: None Encoding: 0110 111a ffff ffff Description: Move data from W to register 'f'. Location 'f' can be anywhere in the 256 byte bank. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: MOVWF REG, 0 Before Instruction W = 0x4F REG = 0xFF After Instruction W = 0x4F REG = 0x4FPIC18FXX2 DS39564C-page 238 © 2006 Microchip Technology Inc. MULLW Multiply Literal with W Syntax: [ label ] MULLW k Operands: 0 ≤ k ≤ 255 Operation: (W) x k → PRODH:PRODL Status Affected: None Encoding: 0000 1101 kkkk kkkk Description: An unsigned multiplication is carried out between the contents of W and the 8-bit literal 'k'. The 16-bit result is placed in PRODH:PRODL register pair. PRODH contains the high byte. W is unchanged. None of the status flags are affected. Note that neither overflow nor carry is possible in this operation. A zero result is possible but not detected. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write registers PRODH: PRODL Example: MULLW 0xC4 Before Instruction W = 0xE2 PRODH = ? PRODL = ? After Instruction W = 0xE2 PRODH = 0xAD PRODL = 0x08 MULWF Multiply W with f Syntax: [ label ] MULWF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: (W) x (f) → PRODH:PRODL Status Affected: None Encoding: 0000 001a ffff ffff Description: An unsigned multiplication is carried out between the contents of W and the register file location 'f'. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both W and 'f' are unchanged. None of the status flags are affected. Note that neither overflow nor carry is possible in this operation. A zero result is possible but not detected. If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write registers PRODH: PRODL Example: MULWF REG, 1 Before Instruction W = 0xC4 REG = 0xB5 PRODH = ? PRODL = ? After Instruction W = 0xC4 REG = 0xB5 PRODH = 0x8A PRODL = 0x94© 2006 Microchip Technology Inc. DS39564C-page 239 PIC18FXX2 NEGF Negate f Syntax: [ label ] NEGF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: ( f ) + 1 → f Status Affected: N, OV, C, DC, Z Encoding: 0110 110a ffff ffff Description: Location ‘f’ is negated using two’s complement. The result is placed in the data memory location 'f'. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: NEGF REG, 1 Before Instruction REG = 0011 1010 [0x3A] After Instruction REG = 1100 0110 [0xC6] NOP No Operation Syntax: [ label ] NOP Operands: None Operation: No operation Status Affected: None Encoding: 0000 1111 0000 xxxx 0000 xxxx 0000 xxxx Description: No operation. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation Example: None.PIC18FXX2 DS39564C-page 240 © 2006 Microchip Technology Inc. POP Pop Top of Return Stack Syntax: [ label ] POP Operands: None Operation: (TOS) → bit bucket Status Affected: None Encoding: 0000 0000 0000 0110 Description: The TOS value is pulled off the return stack and is discarded. The TOS value then becomes the previous value that was pushed onto the return stack. This instruction is provided to enable the user to properly manage the return stack to incorporate a software stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation POP TOS value No operation Example: POP GOTO NEW Before Instruction TOS = 0031A2h Stack (1 level down) = 014332h After Instruction TOS = 014332h PC = NEW PUSH Push Top of Return Stack Syntax: [ label ] PUSH Operands: None Operation: (PC+2) → TOS Status Affected: None Encoding: 0000 0000 0000 0101 Description: The PC+2 is pushed onto the top of the return stack. The previous TOS value is pushed down on the stack. This instruction allows to implement a software stack by modifying TOS, and then push it onto the return stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode PUSH PC+2 onto return stack No operation No operation Example: PUSH Before Instruction TOS = 00345Ah PC = 000124h After Instruction PC = 000126h TOS = 000126h Stack (1 level down) = 00345Ah© 2006 Microchip Technology Inc. DS39564C-page 241 PIC18FXX2 RCALL Relative Call Syntax: [ label ] RCALL n Operands: -1024 ≤ n ≤ 1023 Operation: (PC) + 2 → TOS, (PC) + 2 + 2n → PC Status Affected: None Encoding: 1101 1nnn nnnn nnnn Description: Subroutine call with a jump up to 1K from the current location. First, return address (PC+2) is pushed onto the stack. Then, add the 2’s complement number ’2n’ to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'n' Push PC to stack Process Data Write to PC No operation No operation No operation No operation Example: HERE RCALL Jump Before Instruction PC = Address (HERE) After Instruction PC = Address (Jump) TOS = Address (HERE+2) RESET Reset Syntax: [ label ] RESET Operands: None Operation: Reset all registers and flags that are affected by a MCLR Reset. Status Affected: All Encoding: 0000 0000 1111 1111 Description: This instruction provides a way to execute a MCLR Reset in software. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Start reset No operation No operation Example: RESET After Instruction Registers = Reset Value Flags* = Reset ValuePIC18FXX2 DS39564C-page 242 © 2006 Microchip Technology Inc. RETFIE Return from Interrupt Syntax: [ label ] RETFIE [s] Operands: s ∈ [0,1] Operation: (TOS) → PC, 1 → GIE/GIEH or PEIE/GIEL, if s = 1 (WS) → W, (STATUSS) → STATUS, (BSRS) → BSR, PCLATU, PCLATH are unchanged. Status Affected: GIE/GIEH, PEIE/GIEL. Encoding: 0000 0000 0001 000s Description: Return from Interrupt. Stack is popped and Top-of-Stack (TOS) is loaded into the PC. Interrupts are enabled by setting either the high or low priority global interrupt enable bit. If ‘s’ = 1, the contents of the shadow registers WS, STATUSS and BSRS are loaded into their corresponding registers, W, STATUS and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation pop PC from stack Set GIEH or GIEL No operation No operation No operation No operation Example: RETFIE 1 After Interrupt PC = TOS W = WS BSR = BSRS STATUS = STATUSS GIE/GIEH, PEIE/GIEL = 1 RETLW Return Literal to W Syntax: [ label ] RETLW k Operands: 0 ≤ k ≤ 255 Operation: k → W, (TOS) → PC, PCLATU, PCLATH are unchanged Status Affected: None Encoding: 0000 1100 kkkk kkkk Description: W is loaded with the eight-bit literal 'k'. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data pop PC from stack, Write to W No operation No operation No operation No operation Example: CALL TABLE ; W contains table ; offset value ; W now has ; table value : TABLE ADDWF PCL ; W = offset RETLW k0 ; Begin table RETLW k1 ; : : RETLW kn ; End of table Before Instruction W = 0x07 After Instruction W = value of kn© 2006 Microchip Technology Inc. DS39564C-page 243 PIC18FXX2 RETURN Return from Subroutine Syntax: [ label ] RETURN [s] Operands: s ∈ [0,1] Operation: (TOS) → PC, if s = 1 (WS) → W, (STATUSS) → STATUS, (BSRS) → BSR, PCLATU, PCLATH are unchanged Status Affected: None Encoding: 0000 0000 0001 001s Description: Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter. If ‘s’= 1, the contents of the shadow registers WS, STATUSS and BSRS are loaded into their corresponding registers, W, STATUS and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data pop PC from stack No operation No operation No operation No operation Example: RETURN After Interrupt PC = TOS RLCF Rotate Left f through Carry Syntax: [ label ] RLCF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<7>) → C, (C) → dest<0> Status Affected: C, N, Z Encoding: 0011 01da ffff ffff Description: The contents of register 'f' are rotated one bit to the left through the Carry Flag. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is stored back in register 'f' (default). If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: RLCF REG, 0, 0 Before Instruction REG = 1110 0110 C =0 After Instruction REG = 1110 0110 W = 1100 1100 C =1 C register fPIC18FXX2 DS39564C-page 244 © 2006 Microchip Technology Inc. RLNCF Rotate Left f (no carry) Syntax: [ label ] RLNCF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<7>) → dest<0> Status Affected: N, Z Encoding: 0100 01da ffff ffff Description: The contents of register 'f' are rotated one bit to the left. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is stored back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: RLNCF REG, 1, 0 Before Instruction REG = 1010 1011 After Instruction REG = 0101 0111 register f RRCF Rotate Right f through Carry Syntax: [ label ] RRCF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<0>) → C, (C) → dest<7> Status Affected: C, N, Z Encoding: 0011 00da ffff ffff Description: The contents of register 'f' are rotated one bit to the right through the Carry Flag. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: RRCF REG, 0, 0 Before Instruction REG = 1110 0110 C =0 After Instruction REG = 1110 0110 W = 0111 0011 C =0 C register f© 2006 Microchip Technology Inc. DS39564C-page 245 PIC18FXX2 RRNCF Rotate Right f (no carry) Syntax: [ label ] RRNCF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) → dest, (f<0>) → dest<7> Status Affected: N, Z Encoding: 0100 00da ffff ffff Description: The contents of register 'f' are rotated one bit to the right. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example 1: RRNCF REG, 1, 0 Before Instruction REG = 1101 0111 After Instruction REG = 1110 1011 Example 2: RRNCF REG, 0, 0 Before Instruction W =? REG = 1101 0111 After Instruction W = 1110 1011 REG = 1101 0111 register f SETF Set f Syntax: [ label ] SETF f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: FFh → f Status Affected: None Encoding: 0110 100a ffff ffff Description: The contents of the specified register are set to FFh. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write register 'f' Example: SETF REG,1 Before Instruction REG = 0x5A After Instruction REG = 0xFFPIC18FXX2 DS39564C-page 246 © 2006 Microchip Technology Inc. SLEEP Enter SLEEP mode Syntax: [ label ] SLEEP Operands: None Operation: 00h → WDT, 0 → WDT postscaler, 1 → TO, 0 → PD Status Affected: TO, PD Encoding: 0000 0000 0000 0011 Description: The power-down status bit (PD) is cleared. The time-out status bit (TO) is set. Watchdog Timer and its postscaler are cleared. The processor is put into SLEEP mode with the oscillator stopped. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data Go to sleep Example: SLEEP Before Instruction TO = ? PD = ? After Instruction TO = 1 † PD = 0 † If WDT causes wake-up, this bit is cleared. SUBFWB Subtract f from W with borrow Syntax: [ label ] SUBFWB f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) – (f) – (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 01da ffff ffff Description: Subtract register 'f' and carry flag (borrow) from W (2’s complement method). If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example 1: SUBFWB REG, 1, 0 Before Instruction REG = 3 W =2 C =1 After Instruction REG = FF W =2 C =0 Z =0 N = 1 ; result is negative Example 2: SUBFWB REG, 0, 0 Before Instruction REG = 2 W =5 C =1 After Instruction REG = 2 W =3 C =1 Z =0 N = 0 ; result is positive Example 3: SUBFWB REG, 1, 0 Before Instruction REG = 1 W =2 C =0 After Instruction REG = 0 W =2 C =1 Z = 1 ; result is zero N =0© 2006 Microchip Technology Inc. DS39564C-page 247 PIC18FXX2 SUBLW Subtract W from literal Syntax: [ label ] SUBLW k Operands: 0 ≤ k ≤ 255 Operation: k – (W) → W Status Affected: N, OV, C, DC, Z Encoding: 0000 1000 kkkk kkkk Description: W is subtracted from the eight-bit literal 'k'. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to W Example 1: SUBLW 0x02 Before Instruction W =1 C =? After Instruction W =1 C = 1 ; result is positive Z =0 N =0 Example 2: SUBLW 0x02 Before Instruction W =2 C =? After Instruction W =0 C = 1 ; result is zero Z =1 N =0 Example 3: SUBLW 0x02 Before Instruction W =3 C =? After Instruction W = FF ; (2’s complement) C = 0 ; result is negative Z =0 N =1 SUBWF Subtract W from f Syntax: [ label ] SUBWF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – (W) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 11da ffff ffff Description: Subtract W from register 'f' (2’s complement method). If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example 1: SUBWF REG, 1, 0 Before Instruction REG = 3 W =2 C =? After Instruction REG = 1 W =2 C = 1 ; result is positive Z =0 N =0 Example 2: SUBWF REG, 0, 0 Before Instruction REG = 2 W =2 C =? After Instruction REG = 2 W =0 C = 1 ; result is zero Z =1 N =0 Example 3: SUBWF REG, 1, 0 Before Instruction REG = 1 W =2 C =? After Instruction REG = FFh ;(2’s complement) W =2 C = 0 ; result is negative Z =0 N =1PIC18FXX2 DS39564C-page 248 © 2006 Microchip Technology Inc. SUBWFB Subtract W from f with Borrow Syntax: [ label ] SUBWFB f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f) – (W) – (C) → dest Status Affected: N, OV, C, DC, Z Encoding: 0101 10da ffff ffff Description: Subtract W and the carry flag (borrow) from register 'f' (2’s complement method). If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example 1: SUBWFB REG, 1, 0 Before Instruction REG = 0x19 (0001 1001) W = 0x0D (0000 1101) C =1 After Instruction REG = 0x0C (0000 1011) W = 0x0D (0000 1101) C =1 Z =0 N = 0 ; result is positive Example 2: SUBWFB REG, 0, 0 Before Instruction REG = 0x1B (0001 1011) W = 0x1A (0001 1010) C =0 After Instruction REG = 0x1B (0001 1011) W = 0x00 C =1 Z = 1 ; result is zero N =0 Example 3: SUBWFB REG, 1, 0 Before Instruction REG = 0x03 (0000 0011) W = 0x0E (0000 1101) C =1 After Instruction REG = 0xF5 (1111 0100) ; [2’s comp] W = 0x0E (0000 1101) C =0 Z =0 N = 1 ; result is negative SWAPF Swap f Syntax: [ label ] SWAPF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (f<3:0>) → dest<7:4>, (f<7:4>) → dest<3:0> Status Affected: None Encoding: 0011 10da ffff ffff Description: The upper and lower nibbles of register 'f' are exchanged. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed in register 'f' (default). If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: SWAPF REG, 1, 0 Before Instruction REG = 0x53 After Instruction REG = 0x35© 2006 Microchip Technology Inc. DS39564C-page 249 PIC18FXX2 TBLRD Table Read Syntax: [ label ] TBLRD ( *; *+; *-; +*) Operands: None Operation: if TBLRD *, (Prog Mem (TBLPTR)) → TABLAT; TBLPTR - No Change; if TBLRD *+, (Prog Mem (TBLPTR)) → TABLAT; (TBLPTR) +1 → TBLPTR; if TBLRD *-, (Prog Mem (TBLPTR)) → TABLAT; (TBLPTR) -1 → TBLPTR; if TBLRD +*, (TBLPTR) +1 → TBLPTR; (Prog Mem (TBLPTR)) → TABLAT; Status Affected:None Encoding: 0000 0000 0000 10nn nn=0 * =1 *+ =2 *- =3 +* Description: This instruction is used to read the contents of Program Memory (P.M.). To address the program memory, a pointer called Table Pointer (TBLPTR) is used. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2 Mbyte address range. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLRD instruction can modify the value of TBLPTR as follows: • no change • post-increment • post-decrement • pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read Program Memory) No operation No operation (Write TABLAT) TBLRD Table Read (cont’d) Example1: TBLRD *+ ; Before Instruction TABLAT = 0x55 TBLPTR = 0x00A356 MEMORY(0x00A356) = 0x34 After Instruction TABLAT = 0x34 TBLPTR = 0x00A357 Example2: TBLRD +* ; Before Instruction TABLAT = 0xAA TBLPTR = 0x01A357 MEMORY(0x01A357) = 0x12 MEMORY(0x01A358) = 0x34 After Instruction TABLAT = 0x34 TBLPTR = 0x01A358PIC18FXX2 DS39564C-page 250 © 2006 Microchip Technology Inc. TBLWT Table Write Syntax: [ label ] TBLWT ( *; *+; *-; +*) Operands: None Operation: if TBLWT*, (TABLAT) → Holding Register; TBLPTR - No Change; if TBLWT*+, (TABLAT) → Holding Register; (TBLPTR) +1 → TBLPTR; if TBLWT*-, (TABLAT) → Holding Register; (TBLPTR) -1 → TBLPTR; if TBLWT+*, (TBLPTR) +1 → TBLPTR; (TABLAT) → Holding Register; Status Affected: None Encoding: 0000 0000 0000 11nn nn=0 * =1 *+ =2 *- =3 +* Description: This instruction uses the 3 LSbs of the TBLPTR to determine which of the 8 holding registers the TABLAT data is written to. The 8 holding registers are used to program the contents of Program Memory (P.M.). See Section 5.0 for information on writing to FLASH memory. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2 MBtye address range. The LSb of the TBLPTR selects which byte of the program memory location to access. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLWT instruction can modify the value of TBLPTR as follows: • no change • post-increment • post-decrement • pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read TABLAT) No operation No operation (Write to Holding Register or Memory) TBLWT Table Write (Continued) Example1: TBLWT *+; Before Instruction TABLAT = 0x55 TBLPTR = 0x00A356 HOLDING REGISTER (0x00A356) = 0xFF After Instructions (table write completion) TABLAT = 0x55 TBLPTR = 0x00A357 HOLDING REGISTER (0x00A356) = 0x55 Example 2: TBLWT +*; Before Instruction TABLAT = 0x34 TBLPTR = 0x01389A HOLDING REGISTER (0x01389A) = 0xFF HOLDING REGISTER (0x01389B) = 0xFF After Instruction (table write completion) TABLAT = 0x34 TBLPTR = 0x01389B HOLDING REGISTER (0x01389A) = 0xFF HOLDING REGISTER (0x01389B) = 0x34 © 2006 Microchip Technology Inc. DS39564C-page 251 PIC18FXX2 TSTFSZ Test f, skip if 0 Syntax: [ label ] TSTFSZ f [,a] Operands: 0 ≤ f ≤ 255 a ∈ [0,1] Operation: skip if f = 0 Status Affected: None Encoding: 0110 011a ffff ffff Description: If 'f' = 0, the next instruction, fetched during the current instruction execution, is discarded and a NOP is executed, making this a twocycle instruction. If ’a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE TSTFSZ CNT, 1 NZERO : ZERO : Before Instruction PC = Address (HERE) After Instruction If CNT = 0x00, PC = Address (ZERO) If CNT ≠ 0x00, PC = Address (NZERO) XORLW Exclusive OR literal with W Syntax: [ label ] XORLW k Operands: 0 ≤ k ≤ 255 Operation: (W) .XOR. k → W Status Affected: N, Z Encoding: 0000 1010 kkkk kkkk Description: The contents of W are XORed with the 8-bit literal 'k'. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to W Example: XORLW 0xAF Before Instruction W = 0xB5 After Instruction W = 0x1APIC18FXX2 DS39564C-page 252 © 2006 Microchip Technology Inc. XORWF Exclusive OR W with f Syntax: [ label ] XORWF f [,d [,a] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] a ∈ [0,1] Operation: (W) .XOR. (f) → dest Status Affected: N, Z Encoding: 0001 10da ffff ffff Description: Exclusive OR the contents of W with register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in the register 'f' (default). If ‘a’ is 0, the Access Bank will be selected, overriding the BSR value. If ’a’ is 1, then the bank will be selected as per the BSR value (default). Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Example: XORWF REG, 1, 0 Before Instruction REG = 0xAF W = 0xB5 After Instruction REG = 0x1A W = 0xB5© 2006 Microchip Technology Inc. DS39564C-page 253 PIC18FXX2 21.0 DEVELOPMENT SUPPORT The PICmicro® microcontrollers are supported with a full range of hardware and software development tools: • Integrated Development Environment - MPLAB® IDE Software • Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C17 and MPLAB C18 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian • Simulators - MPLAB SIM Software Simulator • Emulators - MPLAB ICE 2000 In-Circuit Emulator - ICEPIC™ In-Circuit Emulator • In-Circuit Debugger - MPLAB ICD • Device Programmers - PRO MATE® II Universal Device Programmer - PICSTART® Plus Entry-Level Development Programmer • Low Cost Demonstration Boards - PICDEMTM 1 Demonstration Board - PICDEM 2 Demonstration Board - PICDEM 3 Demonstration Board - PICDEM 17 Demonstration Board - KEELOQ® Demonstration Board 21.1 MPLAB Integrated Development Environment Software The MPLAB IDE software brings an ease of software development previously unseen in the 8-bit microcontroller market. The MPLAB IDE is a Windows® based application that contains: • An interface to debugging tools - simulator - programmer (sold separately) - emulator (sold separately) - in-circuit debugger (sold separately) • A full-featured editor • A project manager • Customizable toolbar and key mapping • A status bar • On-line help The MPLAB IDE allows you to: • Edit your source files (either assembly or ‘C’) • One touch assemble (or compile) and download to PICmicro emulator and simulator tools (automatically updates all project information) • Debug using: - source files - absolute listing file - machine code The ability to use MPLAB IDE with multiple debugging tools allows users to easily switch from the costeffective simulator to a full-featured emulator with minimal retraining. 21.2 MPASM Assembler The MPASM assembler is a full-featured universal macro assembler for all PICmicro MCU’s. The MPASM assembler has a command line interface and a Windows shell. It can be used as a stand-alone application on a Windows 3.x or greater system, or it can be used through MPLAB IDE. The MPASM assembler generates relocatable object files for the MPLINK object linker, Intel® standard HEX files, MAP files to detail memory usage and symbol reference, an absolute LST file that contains source lines and generated machine code, and a COD file for debugging. The MPASM assembler features include: • Integration into MPLAB IDE projects. • User-defined macros to streamline assembly code. • Conditional assembly for multi-purpose source files. • Directives that allow complete control over the assembly process. 21.3 MPLAB C17 and MPLAB C18 C Compilers The MPLAB C17 and MPLAB C18 Code Development Systems are complete ANSI ‘C’ compilers for Microchip’s PIC17CXXX and PIC18CXXX family of microcontrollers, respectively. These compilers provide powerful integration capabilities and ease of use not found with other compilers. For easier source level debugging, the compilers provide symbol information that is compatible with the MPLAB IDE memory display.PIC18FXX2 DS39564C-page 254 © 2006 Microchip Technology Inc. 21.4 MPLINK Object Linker/ MPLIB Object Librarian The MPLINK object linker combines relocatable objects created by the MPASM assembler and the MPLAB C17 and MPLAB C18 C compilers. It can also link relocatable objects from pre-compiled libraries, using directives from a linker script. The MPLIB object librarian is a librarian for precompiled code to be used with the MPLINK object linker. When a routine from a library is called from another source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The MPLIB object librarian manages the creation and modification of library files. The MPLINK object linker features include: • Integration with MPASM assembler and MPLAB C17 and MPLAB C18 C compilers. • Allows all memory areas to be defined as sections to provide link-time flexibility. The MPLIB object librarian features include: • Easier linking because single libraries can be included instead of many smaller files. • Helps keep code maintainable by grouping related modules together. • Allows libraries to be created and modules to be added, listed, replaced, deleted or extracted. 21.5 MPLAB SIM Software Simulator The MPLAB SIM software simulator allows code development in a PC-hosted environment by simulating the PICmicro series microcontrollers on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a file, or user-defined key press, to any of the pins. The execution can be performed in single step, execute until break, or trace mode. The MPLAB SIM simulator fully supports symbolic debugging using the MPLAB C17 and the MPLAB C18 C compilers and the MPASM assembler. The software simulator offers the flexibility to develop and debug code outside of the laboratory environment, making it an excellent multiproject software development tool. 21.6 MPLAB ICE High Performance Universal In-Circuit Emulator with MPLAB IDE The MPLAB ICE universal in-circuit emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PICmicro microcontrollers (MCUs). Software control of the MPLAB ICE in-circuit emulator is provided by the MPLAB Integrated Development Environment (IDE), which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the MPLAB ICE in-circuit emulator allows expansion to support new PICmicro microcontrollers. The MPLAB ICE in-circuit emulator system has been designed as a real-time emulation system, with advanced features that are generally found on more expensive development tools. The PC platform and Microsoft® Windows environment were chosen to best make these features available to you, the end user. 21.7 ICEPIC In-Circuit Emulator The ICEPIC low cost, in-circuit emulator is a solution for the Microchip Technology PIC16C5X, PIC16C6X, PIC16C7X and PIC16CXXX families of 8-bit OneTime-Programmable (OTP) microcontrollers. The modular system can support different subsets of PIC16C5X or PIC16CXXX products through the use of interchangeable personality modules, or daughter boards. The emulator is capable of emulating without target application circuitry being present.© 2006 Microchip Technology Inc. DS39564C-page 255 PIC18FXX2 21.8 MPLAB ICD In-Circuit Debugger Microchip's In-Circuit Debugger, MPLAB ICD, is a powerful, low cost, run-time development tool. This tool is based on the FLASH PICmicro MCUs and can be used to develop for this and other PICmicro microcontrollers. The MPLAB ICD utilizes the in-circuit debugging capability built into the FLASH devices. This feature, along with Microchip's In-Circuit Serial ProgrammingTM protocol, offers cost-effective in-circuit FLASH debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by watching variables, single-stepping and setting break points. Running at full speed enables testing hardware in realtime. 21.9 PRO MATE II Universal Device Programmer The PRO MATE II universal device programmer is a full-featured programmer, capable of operating in stand-alone mode, as well as PC-hosted mode. The PRO MATE II device programmer is CE compliant. The PRO MATE II device programmer has programmable VDD and VPP supplies, which allow it to verify programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for instructions and error messages, keys to enter commands and a modular detachable socket assembly to support various package types. In stand-alone mode, the PRO MATE II device programmer can read, verify, or program PICmicro devices. It can also set code protection in this mode. 21.10 PICSTART Plus Entry Level Development Programmer The PICSTART Plus development programmer is an easy-to-use, low cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus development programmer supports all PICmicro devices with up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus development programmer is CE compliant. 21.11 PICDEM 1 Low Cost PICmicro Demonstration Board The PICDEM 1 demonstration board is a simple board which demonstrates the capabilities of several of Microchip’s microcontrollers. The microcontrollers supported are: PIC16C5X (PIC16C54 to PIC16C58A), PIC16C61, PIC16C62X, PIC16C71, PIC16C8X, PIC17C42, PIC17C43 and PIC17C44. All necessary hardware and software is included to run basic demo programs. The user can program the sample microcontrollers provided with the PICDEM 1 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer, and easily test firmware. The user can also connect the PICDEM 1 demonstration board to the MPLAB ICE incircuit emulator and download the firmware to the emulator for testing. A prototype area is available for the user to build some additional hardware and connect it to the microcontroller socket(s). Some of the features include an RS-232 interface, a potentiometer for simulated analog input, push button switches and eight LEDs connected to PORTB. 21.12 PICDEM 2 Low Cost PIC16CXX Demonstration Board The PICDEM 2 demonstration board is a simple demonstration board that supports the PIC16C62, PIC16C64, PIC16C65, PIC16C73 and PIC16C74 microcontrollers. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample microcontrollers provided with the PICDEM 2 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer, and easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 2 demonstration board to test firmware. A prototype area has been provided to the user for adding additional hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push button switches, a potentiometer for simulated analog input, a serial EEPROM to demonstrate usage of the I2CTM bus and separate headers for connection to an LCD module and a keypad.PIC18FXX2 DS39564C-page 256 © 2006 Microchip Technology Inc. 21.13 PICDEM 3 Low Cost PIC16CXXX Demonstration Board The PICDEM 3 demonstration board is a simple demonstration board that supports the PIC16C923 and PIC16C924 in the PLCC package. It will also support future 44-pin PLCC microcontrollers with an LCD Module. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample microcontrollers provided with the PICDEM 3 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer with an adapter socket, and easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 3 demonstration board to test firmware. A prototype area has been provided to the user for adding hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push button switches, a potentiometer for simulated analog input, a thermistor and separate headers for connection to an external LCD module and a keypad. Also provided on the PICDEM 3 demonstration board is a LCD panel, with 4 commons and 12 segments, that is capable of displaying time, temperature and day of the week. The PICDEM 3 demonstration board provides an additional RS-232 interface and Windows software for showing the demultiplexed LCD signals on a PC. A simple serial interface allows the user to construct a hardware demultiplexer for the LCD signals. 21.14 PICDEM 17 Demonstration Board The PICDEM 17 demonstration board is an evaluation board that demonstrates the capabilities of several Microchip microcontrollers, including PIC17C752, PIC17C756A, PIC17C762 and PIC17C766. All necessary hardware is included to run basic demo programs, which are supplied on a 3.5-inch disk. A programmed sample is included and the user may erase it and program it with the other sample programs using the PRO MATE II device programmer, or the PICSTART Plus development programmer, and easily debug and test the sample code. In addition, the PICDEM 17 demonstration board supports downloading of programs to and executing out of external FLASH memory on board. The PICDEM 17 demonstration board is also usable with the MPLAB ICE in-circuit emulator, or the PICMASTER emulator and all of the sample programs can be run and modified using either emulator. Additionally, a generous prototype area is available for user hardware. 21.15 KEELOQ Evaluation and Programming Tools KEELOQ evaluation and programming tools support Microchip’s HCS Secure Data Products. The HCS evaluation kit includes a LCD display to show changing codes, a decoder to decode transmissions and a programming interface to program test transmitters.© 2006 Microchip Technology Inc. DS39564C-page 257 PIC18FXX2 TABLE 21-1: DEVELOPMENT TOOLS FROM MICROCHIP PIC12CXXX PIC14000 PIC16C5X PIC16C6X PIC16CXXX PIC16F62X PIC16C7X PIC16C7XX PIC16C8X/ PIC16F8X PIC16F8XX PIC16C9XX PIC17C4X PIC17C7XX PIC18CXX2 PIC18FXXX 24CXX/ 25CXX/ 93CXX HCSXXX MCRFXXX MCP2510 Software ToolsMPLAB® Integrated Development Environment !!! ! ! ! ! ! ! ! !! ! ! ! MPLAB® C17 C Compiler ! ! MPLAB® C18 C Compiler ! ! MPASMTM Assembler/ MPLINKTM Object Linker !!! ! ! ! ! ! ! ! !! ! ! ! ! ! EmulatorsMPLAB® ICE In-Circuit Emulator !!! ! !!** ! ! ! ! !! ! ! ! ICEPICTM In-Circuit Emulator ! !! ! ! ! ! ! Debugger MPLAB® ICD In-Circuit Debugger !* !* ! ! ProgrammersPICSTART® Plus Entry Level Development Programmer !!! ! !!** ! ! ! ! !! ! ! ! PRO MATE® II Universal Device Programmer !!! ! !!** ! ! ! ! !! ! ! ! ! ! Demo Boards and Eval Kits PICDEMTM 1 Demonstration Board !!!† ! ! PICDEMTM 2 Demonstration Board !† !† ! ! PICDEMTM 3 Demonstration Board ! PICDEMTM 14A Demonstration Board ! PICDEMTM 17 Demonstration Board ! KEELOQ® Evaluation Kit ! KEELOQ® Transponder Kit ! microIDTM Programmer’s Kit ! 125 kHz microIDTM Developer’s Kit ! 125 kHz Anticollision microIDTM Developer’s Kit ! 13.56 MHz Anticollision microIDTM Developer’s Kit ! MCP2510 CAN Developer’s Kit ! * Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB® ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77. ** Contact Microchip Technology Inc. for availability date. † Development tool is available on select devices.PIC18FXX2 DS39564C-page 258 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 259 PIC18FXX2 22.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings (†) Ambient temperature under bias.............................................................................................................-55°C to +125°C Storage temperature .............................................................................................................................. -65°C to +150°C Voltage on any pin with respect to VSS (except VDD, MCLR, and RA4) ......................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V Voltage on RA4 with respect to Vss............................................................................................................... 0V to +8.5V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. ±20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk by PORTA, PORTB, and PORTE (Note 3) (combined)...................................................200 mA Maximum current sourced by PORTA, PORTB, and PORTE (Note 3) (combined)..............................................200 mA Maximum current sunk by PORTC and PORTD (Note 3) (combined)..................................................................200 mA Maximum current sourced by PORTC and PORTD (Note 3) (combined).............................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - ∑ IOH} + ∑ {(VDD-VOH) x IOH} + ∑(VOl x IOL) 2: Voltage spikes below VSS at the MCLR/VPP pin, inducing currents greater than 80 mA, may cause latchup. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/VPP pin, rather than pulling this pin directly to VSS. 3: PORTD and PORTE not available on the PIC18F2X2 devices. † NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.PIC18FXX2 DS39564C-page 260 © 2006 Microchip Technology Inc. FIGURE 22-1: PIC18FXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL) FIGURE 22-2: PIC18LFXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL) Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 40 MHz 5.0V 3.5V 3.0V 2.5V PIC18FXXX 4.2V Frequency Voltage 6.0V 5.5V 4.5V 4.0V 2.0V 40 MHz 5.0V 3.5V 3.0V 2.5V PIC18LFXXX FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz Note: VDDAPPMIN is the minimum voltage of the PICmicro® device in the application. 4 MHz 4.2V© 2006 Microchip Technology Inc. DS39564C-page 261 PIC18FXX2 22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) PIC18LFXX2 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18FXX2 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions VDD Supply Voltage D001 PIC18LFXX2 2.0 — 5.5 V HS, XT, RC and LP Osc mode D001 PIC18FXX2 4.2 — 5.5 V D002 VDR RAM Data Retention Voltage(1) 1.5 — — V D003 VPOR VDD Start Voltage to ensure internal Power-on Reset signal — — 0.7 V See Section 3.1 (Power-on Reset) for details D004 SVDD VDD Rise Rate to ensure internal Power-on Reset signal 0.05 — — V/ms See Section 3.1 (Power-on Reset) for details VBOR Brown-out Reset Voltage D005 PIC18LFXX2 BORV1:BORV0 = 11 1.98 — 2.14 V 85°C ≥ T ≥ 25°C BORV1:BORV0 = 10 2.67 — 2.89 V BORV1:BORV0 = 01 4.16 — 4.5 V BORV1:BORV0 = 00 4.45 — 4.83 V D005 PIC18FXX2 BORV1:BORV0 = 1x N.A. — N.A. V Not in operating voltage range of device BORV1:BORV0 = 01 4.16 — 4.5 V BORV1:BORV0 = 00 4.45 — 4.83 V Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.PIC18FXX2 DS39564C-page 262 © 2006 Microchip Technology Inc. IDD Supply Current(2,4) D010 PIC18LFXX2 — — — — — — — — — .5 .5 1.2 .3 .3 1.5 .3 .3 .75 1 1.25 2 1 1 3 1 1 3 mA mA mA mA mA mA mA mA mA XT osc configuration VDD = 2.0V, +25°C, FOSC = 4 MHz VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz RC osc configuration VDD = 2.0V, +25°C, FOSC = 4 MHz VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz RCIO osc configuration VDD = 2.0V, +25°C, FOSC = 4 MHz VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz D010 PIC18FXX2 — — — — — — — — — 1.2 1.2 1.2 1.5 1.5 1.6 .75 .75 .8 1.5 2 3 3 4 4 2 3 3 mA mA mA mA mA mA mA mA mA XT osc configuration VDD = 4.2V, +25°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz RC osc configuration VDD = 4.2V, +25°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz RCIO osc configuration VDD = 4.2V, +25°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz D010A PIC18LFXX2 — 14 30 μA LP osc, FOSC = 32 kHz, WDT disabled VDD = 2.0V, -40°C to +85°C D010A PIC18FXX2 — — 40 50 70 100 μA μA LP osc, FOSC = 32 kHz, WDT disabled VDD = 4.2V, -40°C to +85°C VDD = 4.2V, -40°C to +125°C 22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued) PIC18LFXX2 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18FXX2 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.© 2006 Microchip Technology Inc. DS39564C-page 263 PIC18FXX2 IDD Supply Current(2,4) (Continued) D010C PIC18LFXX2 — 10 25 mA EC, ECIO osc configurations VDD = 4.2V, -40°C to +85°C D010C PIC18FXX2 — 10 25 mA EC, ECIO osc configurations VDD = 4.2V, -40°C to +125°C D013 PIC18LFXX2 — — — .6 10 15 2 15 25 mA mA mA HS osc configuration FOSC = 4 MHz, VDD = 2.0V FOSC = 25 MHz, VDD = 5.5V HS + PLL osc configurations FOSC = 10 MHz, VDD = 5.5V D013 PIC18FXX2 — — 10 15 15 25 mA mA HS osc configuration FOSC = 25 MHz, VDD = 5.5V HS + PLL osc configurations FOSC = 10 MHz, VDD = 5.5V D014 PIC18LFXX2 — 15 55 μA Timer1 osc configuration FOSC = 32 kHz, VDD = 2.0V D014 PIC18FXX2 — — — — 200 250 μA μA Timer1 osc configuration FOSC = 32 kHz, VDD = 4.2V, -40°C to +85°C FOSC = 32 kHz, VDD = 4.2V, -40°C to +125°C IPD Power-down Current(3) D020 PIC18LFXX2 — — — .08 .1 3 .9 4 10 μA μA μA VDD = 2.0V, +25°C VDD = 2.0V, -40°C to +85°C VDD = 4.2V, -40°C to +85°C D020 D021B PIC18FXX2 — — — .1 3 15 .9 10 25 μA μA μA VDD = 4.2V, +25°C VDD = 4.2V, -40°C to +85°C VDD = 4.2V, -40°C to +125°C 22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued) PIC18LFXX2 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18FXX2 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.PIC18FXX2 DS39564C-page 264 © 2006 Microchip Technology Inc. Module Differential Current D022 ΔIWDT Watchdog Timer PIC18LFXX2 — — — .75 2 10 1.5 8 25 μA μA μA VDD = 2.0V, +25°C VDD = 2.0V, -40°C to +85°C VDD = 4.2V, -40°C to +85°C D022 Watchdog Timer PIC18FXX2 — — — 7 10 25 15 25 40 μA μA μA VDD = 4.2V, +25°C VDD = 4.2V, -40°C to +85°C VDD = 4.2V, -40°C to +125°C D022A ΔIBOR Brown-out Reset(5) PIC18LFXX2 — — — 29 29 33 35 45 50 μA μA μA VDD = 2.0V, +25°C VDD = 2.0V, -40°C to +85°C VDD = 4.2V, -40°C to +85°C D022A Brown-out Reset(5) PIC18FXX2 — — — 36 36 36 40 50 65 μA μA μA VDD = 4.2V, +25°C VDD = 4.2V, -40°C to +85°C VDD = 4.2V, -40°C to +125°C D022B ΔILVD Low Voltage Detect(5) PIC18LFXX2 — — — 29 29 33 35 45 50 μA μA μA VDD = 2.0V, +25°C VDD = 2.0V, -40°C to +85°C VDD = 4.2V, -40°C to +85°C D022B Low Voltage Detect(5) PIC18FXX2 — — — 33 33 33 40 50 65 μA μA μA VDD = 4.2V, +25°C VDD = 4.2V, -40°C to +85°C VDD = 4.2V, -40°C to +125°C D025 ΔITMR1 Timer1 Oscillator PIC18LFXX2 — — — 5.2 5.2 6.5 30 40 50 μA μA μA VDD = 2.0V, +25°C VDD = 2.0V, -40°C to +85°C VDD = 4.2V, -40°C to +85°C D025 Timer1 Oscillator PIC18FXX2 — — — 6.5 6.5 6.5 40 50 65 μA μA μA VDD = 4.2V, +25°C VDD = 4.2V, -40°C to +85°C VDD = 4.2V, -40°C to +125°C 22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued) PIC18LFXX2 (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial PIC18FXX2 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.© 2006 Microchip Technology Inc. DS39564C-page 265 PIC18FXX2 22.2 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Max Units Conditions VIL Input Low Voltage I/O ports: D030 with TTL buffer Vss 0.15 VDD V VDD < 4.5V D030A — 0.8 V 4.5V ≤ VDD ≤ 5.5V D031 with Schmitt Trigger buffer RC3 and RC4 Vss Vss 0.2 VDD 0.3 VDD V V D032 MCLR VSS 0.2 VDD V D032A OSC1 (in XT, HS and LP modes) and T1OSI VSS 0.3 VDD V D033 OSC1 (in RC and EC mode)(1) VSS 0.2 VDD V VIH Input High Voltage I/O ports: D040 with TTL buffer 0.25 VDD + 0.8V VDD V VDD < 4.5V D040A 2.0 VDD V 4.5V ≤ VDD ≤ 5.5V D041 with Schmitt Trigger buffer RC3 and RC4 0.8 VDD 0.7 VDD VDD VDD V V D042 MCLR, OSC1 (EC mode) 0.8 VDD VDD V D042A OSC1 (in XT, HS and LP modes) and T1OSI 0.7 VDD VDD V D043 OSC1 (RC mode)(1) 0.9 VDD VDD V IIL Input Leakage Current(2,3) D060 I/O ports .02 ±1 μA VSS ≤ VPIN ≤ VDD, Pin at hi-impedance D061 MCLR — ±1 μA Vss ≤ VPIN ≤ VDD D063 OSC1 — ±1 μA Vss ≤ VPIN ≤ VDD IPU Weak Pull-up Current D070 IPURB PORTB weak pull-up current 50 450 μA VDD = 5V, VPIN = VSS Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PICmicro device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: Parameter is characterized but not tested.PIC18FXX2 DS39564C-page 266 © 2006 Microchip Technology Inc. VOL Output Low Voltage D080 I/O ports — 0.6 V IOL = 8.5 mA, VDD = 4.5V, -40°C to +85°C D080A — 0.6 V IOL = 7.0 mA, VDD = 4.5V, -40°C to +125°C D083 OSC2/CLKO (RC mode) — 0.6 V IOL = 1.6 mA, VDD = 4.5V, -40°C to +85°C D083A — 0.6 V IOL = 1.2 mA, VDD = 4.5V, -40°C to +125°C VOH Output High Voltage(3) D090 I/O ports VDD – 0.7 — V IOH = -3.0 mA, VDD = 4.5V, -40°C to +85°C D090A VDD – 0.7 — V IOH = -2.5 mA, VDD = 4.5V, -40°C to +125°C D092 OSC2/CLKO (RC mode) VDD – 0.7 — V IOH = -1.3 mA, VDD = 4.5V, -40°C to +85°C D092A VDD – 0.7 — V IOH = -1.0 mA, VDD = 4.5V, -40°C to +125°C D150 VOD Open Drain High Voltage — 8.5 V RA4 pin Capacitive Loading Specs on Output Pins D100(4) COSC2 OSC2 pin — 15 pF In XT, HS and LP modes when external clock is used to drive OSC1 D101 CIO All I/O pins and OSC2 (in RC mode) — 50 pF To meet the AC Timing Specifications D102 CB SCL, SDA — 400 pF In I2C mode 22.2 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued) DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Max Units Conditions Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PICmicro device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: Parameter is characterized but not tested.© 2006 Microchip Technology Inc. DS39564C-page 267 PIC18FXX2 FIGURE 22-3: LOW VOLTAGE DETECT CHARACTERISTICS TABLE 22-1: LOW VOLTAGE DETECT CHARACTERISTICS VLVD LVDIF VDD (LVDIF set by hardware) (LVDIF can be cleared in software) 37 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Symbol Characteristic Min Typ Max Units Conditions D420 VLVD LVD Voltage on VDD transition high to low LVV = 0001 1.98 2.06 2.14 V T ≥ 25°C LVV = 0010 2.18 2.27 2.36 V T ≥ 25°C LVV = 0011 2.37 2.47 2.57 V T ≥ 25°C LVV = 0100 2.48 2.58 2.68 V LVV = 0101 2.67 2.78 2.89 V LVV = 0110 2.77 2.89 3.01 V LVV = 0111 2.98 3.1 3.22 V LVV = 1000 3.27 3.41 3.55 V LVV = 1001 3.47 3.61 3.75 V LVV = 1010 3.57 3.72 3.87 V LVV = 1011 3.76 3.92 4.08 V LVV = 1100 3.96 4.13 4.3 V LVV = 1101 4.16 4.33 4.5 V LVV = 1110 4.45 4.64 4.83 VPIC18FXX2 DS39564C-page 268 © 2006 Microchip Technology Inc. TABLE 22-2: MEMORY PROGRAMMING REQUIREMENTS DC Characteristics Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Param No. Sym Characteristic Min Typ† Max Units Conditions Internal Program Memory Programming Specifications D110 VPP Voltage on MCLR/VPP pin 9.00 — 13.25 V D113 IDDP Supply Current during Programming — — 10 mA Data EEPROM Memory D120 ED Cell Endurance 100K 1M — E/W -40°C to +85°C D121 VDRW VDD for Read/Write VMIN — 5.5 V Using EECON to read/write VMIN = Minimum operating voltage D122 TDEW Erase/Write Cycle Time — 4 — ms D123 TRETD Characteristic Retention 40 — — Year Provided no other specifications are violated D124 TREF Number of Total Erase/Write Cycles before Refresh(1) 1M 10M — E/W -40°C to +85°C Program FLASH Memory D130 EP Cell Endurance 10K 100K — E/W -40°C to +85°C D131 VPR VDD for Read VMIN — 5.5 V VMIN = Minimum operating voltage D132 VIE VDD for Block Erase 4.5 — 5.5 V Using ICSP port D132A VIW VDD for Externally Timed Erase or Write 4.5 — 5.5 V Using ICSP port D132B VPEW VDD for Self-timed Write VMIN — 5.5 V VMIN = Minimum operating voltage D133 TIE ICSP Block Erase Cycle Time — 4 — ms VDD ≥ 4.5V D133A TIW ICSP Erase or Write Cycle Time (externally timed) 1 — — ms VDD ≥ 4.5V D133A TIW Self-timed Write Cycle Time — 2 — ms D134 TRETD Characteristic Retention 40 — — Year Provided no other specifications are violated † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Refer to Section 6.8 for a more detailed discussion on data EEPROM endurance.© 2006 Microchip Technology Inc. DS39564C-page 269 PIC18FXX2 22.3 AC (Timing) Characteristics 22.3.1 TIMING PARAMETER SYMBOLOGY The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 3. TCC:ST (I2C specifications only) 2. TppS 4. Ts (I2C specifications only) T F Frequency T Time Lowercase letters (pp) and their meanings: pp cc CCP1 osc OSC1 ck CLKO rd RD cs CS rw RD or WR di SDI sc SCK do SDO ss SS dt Data in t0 T0CKI io I/O port t1 T1CKI mc MCLR wr WR Uppercase letters and their meanings: S F Fall P Period H High R Rise I Invalid (Hi-impedance) V Valid L Low Z Hi-impedance I 2C only AA output access High High BUF Bus free Low Low TCC:ST (I2C specifications only) CC HD Hold SU Setup ST DAT DATA input hold STO STOP condition STA START conditionPIC18FXX2 DS39564C-page 270 © 2006 Microchip Technology Inc. 22.3.2 TIMING CONDITIONS The temperature and voltages specified in Table 22-3 apply to all timing specifications unless otherwise noted. Figure 22-4 specifies the load conditions for the timing specifications. TABLE 22-3: TEMPERATURE AND VOLTAGE SPECIFICATIONS - AC FIGURE 22-4: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS AC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial -40°C ≤ TA ≤ +125°C for extended Operating voltage VDD range as described in DC spec Section 22.1 and Section 22.2. LC parts operate for industrial temperatures only. VDD/2 CL RL Pin Pin VSS VSS CL RL = 464Ω CL = 50 pF for all pins except OSC2/CLKO and including D and E outputs as ports Load condition 1 Load condition 2© 2006 Microchip Technology Inc. DS39564C-page 271 PIC18FXX2 22.3.3 TIMING DIAGRAMS AND SPECIFICATIONS FIGURE 22-5: EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL) TABLE 22-4: EXTERNAL CLOCK TIMING REQUIREMENTS OSC1 CLKO Q4 Q1 Q2 Q3 Q4 Q1 1 2 3 3 4 4 Param. No. Symbol Characteristic Min Max Units Conditions 1A FOSC External CLKI Frequency(1) DC 40 MHz EC, ECIO, -40°C to +85°C Oscillator Frequency(1) DC 25 MHz EC, ECIO, +85°C to +125°C DC 4 MHz RC osc 0.1 4 MHz XT osc 4 25 MHz HS osc 4 10 MHz HS + PLL osc, -40°C to +85°C 4 6.25 MHz HS + PLL osc, +85°C to +125°C 5 200 kHz LP Osc mode 1 TOSC External CLKI Period(1) 25 — ns EC, ECIO, -40°C to +85°C Oscillator Period(1) 40 — ns EC, ECIO, +85°C to +125°C 250 — ns RC osc 250 10,000 ns XT osc 40 250 ns HS osc 100 250 ns HS + PLL osc, -40°C to +85°C 160 250 ns HS + PLL osc, +85°C to +125°C 25 — μs LP osc 2 TCY Instruction Cycle Time(1) 100 — ns TCY = 4/FOSC, -40°C to +85°C 160 — ns TCY = 4/FOSC, +85°C to +125°C 3 TosL, TosH External Clock in (OSC1) High or Low Time 30 — ns XT osc 2.5 — μs LP osc 10 — ns HS osc 4 TosR, TosF External Clock in (OSC1) Rise or Fall Time — 20 ns XT osc — 50 ns LP osc — 7.5 ns HS osc Note 1: Instruction cycle period (TCY) equals four times the input oscillator time-base period for all configurations except PLL. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.PIC18FXX2 DS39564C-page 272 © 2006 Microchip Technology Inc. TABLE 22-5: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2 TO 5.5V) FIGURE 22-6: CLKO AND I/O TIMING Param No. Sym Characteristic Min Typ† Max Units Conditions — FOSC Oscillator Frequency Range 4 — 10 MHz HS mode only — FSYS On-chip VCO System Frequency 16 — 40 MHz HS mode only — trc PLL Start-up Time (Lock Time) — — 2 ms — ΔCLK CLKO Stability (Jitter) -2 — +2 % † Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note: Refer to Figure 22-4 for load conditions. OSC1 CLKO I/O Pin (input) I/O Pin (output) Q4 Q1 Q2 Q3 10 13 14 17 20, 21 19 18 15 11 12 16 Old Value New Value© 2006 Microchip Technology Inc. DS39564C-page 273 PIC18FXX2 TABLE 22-6: CLKO AND I/O TIMING REQUIREMENTS FIGURE 22-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING Param. No. Symbol Characteristic Min Typ Max Units Conditions 10 TosH2ckL OSC1↑ to CLKO↓ — 75 200 ns (Note 1) 11 TosH2ckH OSC1↑ to CLKO↑ — 75 200 ns (Note 1) 12 TckR CLKO rise time — 35 100 ns (Note 1) 13 TckF CLKO fall time — 35 100 ns (Note 1) 14 TckL2ioV CLKO↓ to Port out valid — — 0.5 TCY + 20 ns (Note 1) 15 TioV2ckH Port in valid before CLKO ↑ 0.25 TCY + 25 — — ns (Note 1) 16 TckH2ioI Port in hold after CLKO ↑ 0 — — ns (Note 1) 17 TosH2ioV OSC1↑ (Q1 cycle) to Port out valid — 50 150 ns 18 TosH2ioI OSC1↑ (Q2 cycle) to Port input invalid (I/O in hold time) PIC18FXXX 100 — — ns 18A PIC18LFXXX 200 — — ns 19 TioV2osH Port input valid to OSC1↑ (I/O in setup time) 0 — — ns 20 TioR Port output rise time PIC18FXXX — 10 25 ns 20A PIC18LFXXX — — 60 ns VDD = 2V 21 TioF Port output fall time PIC18FXXX — 10 25 ns 21A PIC18LFXXX — — 60 ns VDD = 2V 22†† TINP INT pin high or low time TCY — — ns 23†† TRBP RB7:RB4 change INT high or low time TCY — — ns 24†† TRCP RC7:RC4 change INT high or low time 20 ns †† These parameters are asynchronous events not related to any internal clock edges. Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC. VDD MCLR Internal POR PWRT Time-out OSC Time-out Internal Reset Watchdog Timer Reset 33 32 30 31 34 I/O Pins 34 Note: Refer to Figure 22-4 for load conditions.PIC18FXX2 DS39564C-page 274 © 2006 Microchip Technology Inc. FIGURE 22-8: BROWN-OUT RESET TIMING TABLE 22-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER AND BROWN-OUT RESET REQUIREMENTS VDD BVDD 35 VBGAP = 1.2V VIRVST Enable Internal Reference Voltage Internal Reference Voltage stable 36 Typical Param. No. Symbol Characteristic Min Typ Max Units Conditions 30 TmcL MCLR Pulse Width (low) 2 — — μs 31 TWDT Watchdog Timer Time-out Period (No Postscaler) 7 18 33 ms 32 TOST Oscillation Start-up Timer Period 1024 TOSC — 1024 TOSC — TOSC = OSC1 period 33 TPWRT Power up Timer Period 28 72 132 ms 34 TIOZ I/O Hi-impedance from MCLR Low or Watchdog Timer Reset —2— μs 35 TBOR Brown-out Reset Pulse Width 200 — — μs VDD ≤ BVDD (see D005) 36 TIVRST Time for Internal Reference Voltage to become stable — 20 500 μs 37 TLVD Low Voltage Detect Pulse Width 200 — — μs VDD ≤ VLVD (see D420)© 2006 Microchip Technology Inc. DS39564C-page 275 PIC18FXX2 FIGURE 22-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS TABLE 22-8: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS Note: Refer to Figure 22-4 for load conditions. 46 47 45 48 41 42 40 T0CKI T1OSO/T1CKI TMR0 or TMR1 Param No. Symbol Characteristic Min Max Units Conditions 40 Tt0H T0CKI High Pulse Width No Prescaler 0.5TCY + 20 — ns With Prescaler 10 — ns 41 Tt0L T0CKI Low Pulse Width No Prescaler 0.5TCY + 20 — ns With Prescaler 10 — ns 42 Tt0P T0CKI Period No Prescaler TCY + 10 — ns With Prescaler Greater of: 20 nS or TCY + 40 N — ns N = prescale value (1, 2, 4,..., 256) 45 Tt1H T1CKI High Time Synchronous, no prescaler 0.5TCY + 20 — ns Synchronous, with prescaler PIC18FXXX 10 — ns PIC18LFXXX 25 — ns Asynchronous PIC18FXXX 30 — ns PIC18LFXXX 50 — ns 46 Tt1L T1CKI Low Time Synchronous, no prescaler 0.5TCY + 5 — ns Synchronous, with prescaler PIC18FXXX 10 — ns PIC18LFXXX 25 — ns Asynchronous PIC18FXXX 30 — ns PIC18LFXXX 50 — ns 47 Tt1P T1CKI input period Synchronous Greater of: 20 nS or TCY + 40 N — ns N = prescale value (1, 2, 4, 8) Asynchronous 60 — ns Ft1 T1CKI oscillator input frequency range DC 50 kHz 48 Tcke2tmrI Delay from external T1CKI clock edge to timer increment 2 TOSC 7 TOSC —PIC18FXX2 DS39564C-page 276 © 2006 Microchip Technology Inc. FIGURE 22-10: CAPTURE/COMPARE/PWM TIMINGS (CCP1 AND CCP2) TABLE 22-9: CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1 AND CCP2) Note: Refer to Figure 22-4 for load conditions. CCPx (Capture Mode) 50 51 52 CCPx 53 54 (Compare or PWM Mode) Param. No. Symbol Characteristic Min Max Units Conditions 50 TccL CCPx input low time No Prescaler 0.5 TCY + 20 — ns With Prescaler PIC18FXXX 10 — ns PIC18LFXXX 20 — ns 51 TccH CCPx input high time No Prescaler 0.5 TCY + 20 — ns With Prescaler PIC18FXXX 10 — ns PIC18LFXXX 20 — ns 52 TccP CCPx input period 3 TCY + 40 N — ns N = prescale value (1,4 or 16) 53 TccR CCPx output fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 54 TccF CCPx output fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V© 2006 Microchip Technology Inc. DS39564C-page 277 PIC18FXX2 FIGURE 22-11: PARALLEL SLAVE PORT TIMING (PIC18F4X2) TABLE 22-10: PARALLEL SLAVE PORT REQUIREMENTS (PIC18F4X2) Note: Refer to Figure 22-4 for load conditions. RE2/CS RE0/RD RE1/WR RD7:RD0 62 63 64 65 Param. No. Symbol Characteristic Min Max Units Conditions 62 TdtV2wrH Data in valid before WR↑ or CS↑ (setup time) 20 25 — — ns ns Extended Temp. Range 63 TwrH2dtI WR↑ or CS↑ to data–in invalid (hold time) PIC18FXXX 20 — ns PIC18LFXXX 35 — ns VDD = 2V 64 TrdL2dtV RD↓ and CS↓ to data–out valid — — 80 90 ns ns Extended Temp. Range 65 TrdH2dtI RD↑ or CS↓ to data–out invalid 10 30 ns 66 TibfINH Inhibit of the IBF flag bit being cleared from WR↑ or CS↑ — 3 TCYPIC18FXX2 DS39564C-page 278 © 2006 Microchip Technology Inc. FIGURE 22-12: EXAMPLE SPI MASTER MODE TIMING (CKE = 0) TABLE 22-11: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0) Param. No. Symbol Characteristic Min Max Units Conditions 70 TssL2scH, TssL2scL SS↓ to SCK↓ or SCK↑ input TCY — ns 71 TscH SCK input high time (Slave mode) Continuous 1.25 TCY + 30 — ns 71A Single Byte 40 — ns (Note 1) 72 TscL SCK input low time (Slave mode) Continuous 1.25 TCY + 30 — ns 72A Single Byte 40 — ns (Note 1) 73 TdiV2scH, TdiV2scL Setup time of SDI data input to SCK edge 100 — ns 73A TB2B Last clock edge of Byte1 to the 1st clock edge of Byte2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold time of SDI data input to SCK edge 100 — ns 75 TdoR SDO data output rise time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 76 TdoF SDO data output fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 80 TscH2doV, TscL2doV SDO data output valid after SCK edge PIC18FXXX — 50 ns PIC18LFXXX — 150 ns VDD = 2V Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 70 71 72 73 74 75, 76 79 78 80 78 79 MSb LSb bit6 - - - - - -1 MSb In bit6 - - - -1 LSb In Note: Refer to Figure 22-4 for load conditions.© 2006 Microchip Technology Inc. DS39564C-page 279 PIC18FXX2 FIGURE 22-13: EXAMPLE SPI MASTER MODE TIMING (CKE = 1) TABLE 22-12: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1) Param. No. Symbol Characteristic Min Max Units Conditions 71 TscH SCK input high time (Slave mode) Continuous 1.25 TCY + 30 — ns 71A Single Byte 40 — ns (Note 1) 72 TscL SCK input low time (Slave mode) Continuous 1.25 TCY + 30 — ns 72A Single Byte 40 — ns (Note 1) 73 TdiV2scH, TdiV2scL Setup time of SDI data input to SCK edge 100 — ns 73A TB2B Last clock edge of Byte1 to the 1st clock edge of Byte2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold time of SDI data input to SCK edge 100 — ns 75 TdoR SDO data output rise time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 76 TdoF SDO data output fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 80 TscH2doV, TscL2doV SDO data output valid after SCK edge PIC18FXXX — 50 ns PIC18LFXXX — 150 ns VDD = 2V 81 TdoV2scH, TdoV2scL SDO data output setup to SCK edge TCY — ns Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 81 71 72 74 75, 76 78 80 MSb 79 73 MSb In bit6 - - - - - -1 bit6 - - - -1 LSb In LSb Note: Refer to Figure 22-4 for load conditions.PIC18FXX2 DS39564C-page 280 © 2006 Microchip Technology Inc. FIGURE 22-14: EXAMPLE SPI SLAVE MODE TIMING (CKE = 0) TABLE 22-13: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING (CKE = 0)) Param. No. Symbol Characteristic Min Max Units Conditions 70 TssL2scH, TssL2scL SS↓ to SCK↓ or SCK↑ input TCY — ns 71 TscH SCK input high time (Slave mode) Continuous 1.25 TCY + 30 — ns 71A Single Byte 40 — ns (Note 1) 72 TscL SCK input low time (Slave mode) Continuous 1.25 TCY + 30 — ns 72A Single Byte 40 — ns (Note 1) 73 TdiV2scH, TdiV2scL Setup time of SDI data input to SCK edge 100 — ns 73A TB2B Last clock edge of Byte1 to the first clock edge of Byte2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold time of SDI data input to SCK edge 100 — ns 75 TdoR SDO data output rise time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 76 TdoF SDO data output fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 77 TssH2doZ SS↑ to SDO output hi-impedance 10 50 ns 78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 80 TscH2doV, TscL2doV SDO data output valid after SCK edge PIC18FXXX — 50 ns PIC18LFXXX — 150 ns VDD = 2V 83 TscH2ssH, TscL2ssH SS ↑ after SCK edge 1.5 TCY + 40 — ns Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 70 71 72 73 74 75, 76 77 79 78 80 78 79 SDI MSb LSb bit6 - - - - - -1 MSb In bit6 - - - -1 LSb In 83 Note: Refer to Figure 22-4 for load conditions.© 2006 Microchip Technology Inc. DS39564C-page 281 PIC18FXX2 FIGURE 22-15: EXAMPLE SPI SLAVE MODE TIMING (CKE = 1) TABLE 22-14: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1) Param. No. Symbol Characteristic Min Max Units Conditions 70 TssL2scH, TssL2scL SS↓ to SCK↓ or SCK↑ input TCY — ns 71 TscH SCK input high time (Slave mode) Continuous 1.25 TCY + 30 — ns 71A Single Byte 40 — ns (Note 1) 72 TscL SCK input low time (Slave mode) Continuous 1.25 TCY + 30 — ns 72A Single Byte 40 — ns (Note 1) 73A TB2B Last clock edge of Byte1 to the first clock edge of Byte2 1.5 TCY + 40 — ns (Note 2) 74 TscH2diL, TscL2diL Hold time of SDI data input to SCK edge 100 — ns 75 TdoR SDO data output rise time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 76 TdoF SDO data output fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 77 TssH2doZ SS↑ to SDO output hi-impedance 10 50 ns 78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 80 TscH2doV, TscL2doV SDO data output valid after SCK edge PIC18FXXX — 50 ns PIC18LFXXX — 150 ns VDD = 2V 82 TssL2doV SDO data output valid after SS↓ edge PIC18FXXX — 50 ns PIC18LFXXX — 150 ns VDD = 2V 83 TscH2ssH, TscL2ssH SS ↑ after SCK edge 1.5 TCY + 40 — ns Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used. SS SCK (CKP = 0) SCK (CKP = 1) SDO SDI 70 71 72 82 74 75, 76 MSb bit6 - - - - - -1 LSb 77 MSb In bit6 - - - -1 LSb In 80 83 Note: Refer to Figure 22-4 for load conditions.PIC18FXX2 DS39564C-page 282 © 2006 Microchip Technology Inc. FIGURE 22-16: I2C BUS START/STOP BITS TIMING TABLE 22-15: I2C BUS START/STOP BITS REQUIREMENTS (SLAVE MODE) FIGURE 22-17: I2C BUS DATA TIMING Note: Refer to Figure 22-4 for load conditions. 91 92 93 SCL SDA START Condition STOP Condition 90 Param. No. Symbol Characteristic Min Max Units Conditions 90 TSU:STA START condition 100 kHz mode 4700 — ns Only relevant for Repeated Setup time 400 kHz mode 600 — START condition 91 THD:STA START condition 100 kHz mode 4000 — ns After this period, the first Hold time 400 kHz mode 600 — clock pulse is generated 92 TSU:STO STOP condition 100 kHz mode 4700 — ns Setup time 400 kHz mode 600 — 93 THD:STO STOP condition 100 kHz mode 4000 — ns Hold time 400 kHz mode 600 — Note: Refer to Figure 22-4 for load conditions. 90 91 92 100 101 103 106 107 109 109 110 102 SCL SDA In SDA Out© 2006 Microchip Technology Inc. DS39564C-page 283 PIC18FXX2 TABLE 22-16: I2C BUS DATA REQUIREMENTS (SLAVE MODE) Param. No. Symbol Characteristic Min Max Units Conditions 100 THIGH Clock high time 100 kHz mode 4.0 — μs PIC18FXXX must operate at a minimum of 1.5 MHz 400 kHz mode 0.6 — μs PIC18FXXX must operate at a minimum of 10 MHz SSP Module 1.5 TCY — 101 TLOW Clock low time 100 kHz mode 4.7 — μs PIC18FXXX must operate at a minimum of 1.5 MHz 400 kHz mode 1.3 — μs PIC18FXXX must operate at a minimum of 10 MHz SSP Module 1.5 TCY — 102 TR SDA and SCL rise time 100 kHz mode — 1000 ns 400 kHz mode 20 + 0.1 CB 300 ns CB is specified to be from 10 to 400 pF 103 TF SDA and SCL fall time 100 kHz mode — 1000 ns VDD ≥ 4.2V 400 kHz mode 20 + 0.1 CB 300 ns VDD ≥ 4.2V 90 TSU:STA START condition setup time 100 kHz mode 4.7 — μs Only relevant for Repeated START condition 400 kHz mode 0.6 — μs 91 THD:STA START condition hold time 100 kHz mode 4.0 — μs After this period, the first clock pulse is generated 400 kHz mode 0.6 — μs 106 THD:DAT Data input hold time 100 kHz mode 0 — ns 400 kHz mode 0 0.9 μs 107 TSU:DAT Data input setup time 100 kHz mode 250 — ns (Note 2) 400 kHz mode 100 — ns 92 TSU:STO STOP condition setup time 100 kHz mode 4.7 — μs 400 kHz mode 0.6 — μs 109 TAA Output valid from clock 100 kHz mode — 3500 ns (Note 1) 400 kHz mode — — ns 110 TBUF Bus free time 100 kHz mode 4.7 — μs Time the bus must be free before a new transmission can start 400 kHz mode 1.3 — μs D102 CB Bus capacitive loading — 400 pF Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions. 2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but the requirement TSU:DAT ≥ 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line. TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification) before the SCL line is released. PIC18FXX2 DS39564C-page 284 © 2006 Microchip Technology Inc. FIGURE 22-18: MASTER SSP I2C BUS START/STOP BITS TIMING WAVEFORMS TABLE 22-17: MASTER SSP I2C BUS START/STOP BITS REQUIREMENTS FIGURE 22-19: MASTER SSP I2C BUS DATA TIMING Note: Refer to Figure 22-4 for load conditions. 91 93 SCL SDA START Condition STOP Condition 90 92 Param. No. Symbol Characteristic Min Max Units Conditions 90 TSU:STA START condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Only relevant for Repeated START condition Setup time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — 91 THD:STA START condition 100 kHz mode 2(TOSC)(BRG + 1) — ns After this period, the first clock pulse is generated Hold time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — 92 TSU:STO STOP condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Setup time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — 93 THD:STO STOP condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Hold time 400 kHz mode 2(TOSC)(BRG + 1) — 1 MHz mode(1) 2(TOSC)(BRG + 1) — Note 1: Maximum pin capacitance = 10 pF for all I2C pins. Note: Refer to Figure 22-4 for load conditions. 90 91 92 100 101 103 106 107 109 109 110 102 SCL SDA In SDA Out© 2006 Microchip Technology Inc. DS39564C-page 285 PIC18FXX2 TABLE 22-18: MASTER SSP I2C BUS DATA REQUIREMENTS Param. No. Symbol Characteristic Min Max Units Conditions 100 THIGH Clock high time 100 kHz mode 2(TOSC)(BRG + 1) — ms 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 101 TLOW Clock low time 100 kHz mode 2(TOSC)(BRG + 1) — ms 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 102 TR SDA and SCL rise time 100 kHz mode — 1000 ns CB is specified to be from 10 to 400 pF 400 kHz mode 20 + 0.1 CB 300 ns 1 MHz mode(1) — 300 ns 103 TF SDA and SCL fall time 100 kHz mode — 1000 ns VDD ≥ 4.2V 400 kHz mode 20 + 0.1 CB 300 ns VDD ≥ 4.2V 90 TSU:STA START condition setup time 100 kHz mode 2(TOSC)(BRG + 1) — ms Only relevant for Repeated START condition 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 91 THD:STA START condition hold time 100 kHz mode 2(TOSC)(BRG + 1) — ms After this period, the first clock pulse is generated 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 106 THD:DAT Data input hold time 100 kHz mode 0 — ns 400 kHz mode 0 0.9 ms 107 TSU:DAT Data input setup time 100 kHz mode 250 — ns (Note 2) 400 kHz mode 100 — ns 92 TSU:STO STOP condition setup time 100 kHz mode 2(TOSC)(BRG + 1) — ms 400 kHz mode 2(TOSC)(BRG + 1) — ms 1 MHz mode(1) 2(TOSC)(BRG + 1) — ms 109 TAA Output valid from clock 100 kHz mode — 3500 ns 400 kHz mode — 1000 ns 1 MHz mode(1) — — ns 110 TBUF Bus free time 100 kHz mode 4.7 — ms Time the bus must be free before a new transmission can start 400 kHz mode 1.3 — ms D102 CB Bus capacitive loading — 400 pF Note 1: Maximum pin capacitance = 10 pF for all I2C pins. 2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 ≥ 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line is released.PIC18FXX2 DS39564C-page 286 © 2006 Microchip Technology Inc. FIGURE 22-20: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING TABLE 22-19: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS FIGURE 22-21: USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING TABLE 22-20: USART SYNCHRONOUS RECEIVE REQUIREMENTS 121 121 120 122 RC6/TX/CK RC7/RX/DT pin pin Note: Refer to Figure 22-4 for load conditions. Param. No. Symbol Characteristic Min Max Units Conditions 120 TckH2dtV SYNC XMIT (MASTER & SLAVE) Clock high to data out valid PIC18FXXX — 50 ns PIC18LFXXX — 150 ns VDD = 2V 121 Tckr Clock out rise time and fall time (Master mode) PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 122 Tdtr Data out rise time and fall time PIC18FXXX — 25 ns PIC18LFXXX — 60 ns VDD = 2V 125 126 RC6/TX/CK RC7/RX/DT pin pin Note: Refer to Figure 22-4 for load conditions. Param. No. Symbol Characteristic Min Max Units Conditions 125 TdtV2ckl SYNC RCV (MASTER & SLAVE) Data hold before CK ↓ (DT hold time) 10 — ns 126 TckL2dtl Data hold after CK ↓ (DT hold time) PIC18FXXX 15 — ns PIC18LFXXX 20 — ns VDD = 2V© 2006 Microchip Technology Inc. DS39564C-page 287 PIC18FXX2 TABLE 22-21: A/D CONVERTER CHARACTERISTICS: PIC18FXX2 (INDUSTRIAL, EXTENDED) PIC18LFXX2 (INDUSTRIAL) FIGURE 22-22: A/D CONVERSION TIMING Param No. Symbol Characteristic Min Typ Max Units Conditions A01 NR Resolution — — 10 bit A03 EIL Integral linearity error — — <±1 LSb VREF = VDD = 5.0V A04 EDL Differential linearity error — — <±1 LSb VREF = VDD = 5.0V A05 EG Gain error — — <±1 LSb VREF = VDD = 5.0V A06 EOFF Offset error — — <±1.5 LSb VREF = VDD = 5.0V A10 — Monotonicity guaranteed(2) — VSS ≤ VAIN ≤ VREF A20 A20A VREF Reference Voltage (VREFH – VREFL) 1.8V 3V — — — — V V VDD < 3.0V VDD ≥ 3.0V A21 VREFH Reference voltage High AVSS — AVDD + 0.3V V A22 VREFL Reference voltage Low AVSS – 0.3V — VREFH V A25 VAIN Analog input voltage AVSS – 0.3V — AVDD + 0.3V V VDD ≥ 2.5V (Note 3) A30 ZAIN Recommended impedance of analog voltage source — — 2.5 kΩ (Note 4) A50 IREF VREF input current (Note 1) — — — — 5 150 μA μA During VAIN acquisition During A/D conversion cycle Note 1: Vss ≤ VAIN ≤ VREF 2: The A/D conversion result never decreases with an increase in the Input Voltage, and has no missing codes. 3: For VDD < 2.5V, VAIN should be limited to < .5 VDD. 4: Maximum allowed impedance for analog voltage source is 10 kΩ. This requires higher acquisition times. 131 130 132 BSF ADCON0, GO Q4 A/D CLK A/D DATA ADRES ADIF GO SAMPLE OLD_DATA SAMPLING STOPPED DONE NEW_DATA (Note 2) 9 87 2 1 0 Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. 2: This is a minimal RC delay (typically 100 nS), which also disconnects the holding capacitor from the analog input. . . . . . . TCYPIC18FXX2 DS39564C-page 288 © 2006 Microchip Technology Inc. TABLE 22-22: A/D CONVERSION REQUIREMENTS Param No. Symbol Characteristic Min Max Units Conditions 130 TAD A/D clock period PIC18FXXX 1.6 20(4) μs TOSC based PIC18FXXX 2.0 6.0 μs A/D RC mode 131 TCNV Conversion time (not including acquisition time) (Note 1) 11 12 TAD 132 TACQ Acquisition time (Note 2) 5 10 — — μs μs VREF = VDD = 5.0V VREF = VDD = 2.5V 135 TSWC Switching Time from convert → sample — (Note 3) Note 1: ADRES register may be read on the following TCY cycle. 2: The time for the holding capacitor to acquire the “New” input voltage, when the new input value has not changed by more than 1 LSB from the last sampled voltage. The source impedance (RS) on the input channels is 50Ω. See Section 17.0 for more information on acquisition time consideration. 3: On the next Q4 cycle of the device clock. 4: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider. © 2006 Microchip Technology Inc. DS39564C-page 289 PIC18FXX2 23.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES “Typical” represents the mean of the distribution at 25°C. “Maximum” or “minimum” represents (mean + 3σ) or (mean - 3σ) respectively, where σ is a standard deviation, over the whole temperature range. FIGURE 23-1: TYPICAL IDD vs. FOSC OVER VDD (HS MODE) FIGURE 23-2: MAXIMUM IDD vs. FOSC OVER VDD (HS MODE) Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore, outside the warranted range. 0 2 4 6 8 10 12 4 6 8 10 12 14 16 18 20 22 24 26 FOSC (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0 2 4 6 8 10 12 4 6 8 10 12 14 16 18 20 22 24 26 FOSC (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C)PIC18FXX2 DS39564C-page 290 © 2006 Microchip Technology Inc. FIGURE 23-3: TYPICAL IDD vs. FOSC OVER VDD (HS/PLL MODE) FIGURE 23-4: MAXIMUM IDD vs. FOSC OVER VDD (HS/PLL MODE) 0 2 4 6 8 10 12 14 16 18 20 4 5 6 7 8 9 10 FOSC (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.2V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0 2 4 6 8 10 12 14 16 18 20 4 5 6 7 8 9 10 FOSC (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.2V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C)© 2006 Microchip Technology Inc. DS39564C-page 291 PIC18FXX2 FIGURE 23-5: TYPICAL IDD vs. FOSC OVER VDD (XT MODE) FIGURE 23-6: MAXIMUM IDD vs. FOSC OVER VDD (XT MODE) 0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FOSC (MHz) IDD (uA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) IDD (μA) 0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FOSC (MHz) IDD (μA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C)PIC18FXX2 DS39564C-page 292 © 2006 Microchip Technology Inc. FIGURE 23-7: TYPICAL IDD vs. FOSC OVER VDD (LP MODE) FIGURE 23-8: MAXIMUM IDD vs. FOSC OVER VDD (LP MODE) 0 10 20 30 40 50 60 70 80 90 100 20 30 40 50 60 70 80 90 100 FOSC (kHz) IDD (uA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0 20 40 60 80 100 120 140 20 30 40 50 60 70 80 90 100 FOSC (kHz) IDD (uA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C)© 2006 Microchip Technology Inc. DS39564C-page 293 PIC18FXX2 FIGURE 23-9: TYPICAL IDD vs. FOSC OVER VDD (EC MODE) FIGURE 23-10: MAXIMUM IDD vs. FOSC OVER VDD (EC MODE) 0 2 4 6 8 10 12 14 16 4 8 12 16 20 24 28 32 36 40 FOSC (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 4.2V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0 2 4 6 8 10 12 14 16 4 8 12 16 20 24 28 32 36 40 FOSC (MHz) IDD (mA) 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 4.2V Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C)PIC18FXX2 DS39564C-page 294 © 2006 Microchip Technology Inc. FIGURE 23-11: TYPICAL AND MAXIMUM IDD vs. VDD (TIMER1 AS MAIN OSCILLATOR, 32.768 kHz, C1 AND C2 = 47 pF) FIGURE 23-12: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 20 pF, +25°C) 0 20 40 60 80 100 120 140 160 180 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) Typ (25C) Max (70C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-10°C to 70°C) Minimum: mean – 3σ (-10°C to 70°C) IDD (μA) Max (+70°C) Typ (+25°C) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (kHz) 3.3kΩ 5.1kΩ 10kΩ 100kΩ Operation above 4 MHz is not recommended.© 2006 Microchip Technology Inc. DS39564C-page 295 PIC18FXX2 FIGURE 23-13: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 100 pF, +25°C) FIGURE 23-14: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 300 pF, +25°C) 0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (kHz) 3.3kΩ 5.1kΩ 10kΩ 100kΩ 0 100 200 300 400 500 600 700 800 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) Freq (MHz) 3.3kΩ 5.1kΩ 10kΩ 100kΩPIC18FXX2 DS39564C-page 296 © 2006 Microchip Technology Inc. FIGURE 23-15: IPD vs. VDD, -40°C TO +125°C (SLEEP MODE, ALL PERIPHERALS DISABLED) FIGURE 23-16: ΔIBOR vs. VDD OVER TEMPERATURE (BOR ENABLED, VBOR = 2.00 - 2.16V) 0.01 0.1 1 10 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) Typ (+25°C) Max (+85°C) Max (-40°C to +125°C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0 10 20 30 40 50 60 70 80 90 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (μA) Max (125C) Max (85C) Typ (25C) Device Held in Reset Device in Sleep Max (+125°C) Max (+85°C) Typ (+25°C) Device Held in RESET Device in SLEEP© 2006 Microchip Technology Inc. DS39564C-page 297 PIC18FXX2 FIGURE 23-17: TYPICAL AND MAXIMUM ΔITMR1 vs. VDD OVER TEMPERATURE (-10°C TO +70°C, TIMER1 WITH OSCILLATOR, XTAL = 32 kHz, C1 AND C2 = 47 pF) FIGURE 23-18: TYPICAL AND MAXIMUM ΔIWDT vs. VDD OVER TEMPERATURE (WDT ENABLED) 0 2 4 6 8 10 12 14 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (uA) Typ (25C) Max (70C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-10°C to 70°C) Minimum: mean – 3σ (-10°C to 70°C) IPD (μA) Max (+70°C) Typ (+25°C) 0 10 20 30 40 50 60 70 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IPD (μA) Max (125C) Max (85C) Typ (25C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) Max (+125°C) Max (+85°C) Typ (+25°C)PIC18FXX2 DS39564C-page 298 © 2006 Microchip Technology Inc. FIGURE 23-19: TYPICAL, MINIMUM AND MAXIMUM WDT PERIOD vs. VDD (-40°C TO +125°C) FIGURE 23-20: ΔILVD vs. VDD OVER TEMPERATURE (LVD ENABLED, VLVD = 4.5 - 4.78V) 0 5 10 15 20 25 30 35 40 45 50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) WDT Period (ms) Max (125C) MAX (85C) Typ (25C) Min (-40C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) Max (+125°C) Max (+85°C) Typ (+25°C) Min (-40°C) 0 10 20 30 40 50 60 70 80 90 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) IDD (μA) Max (125C) Typ (25C) Max (125C) Typ (25C) LVDIF is set by hardware LVDIF can be cleared by firmware LVDIF state is unknown Max (+125°C) Max (+125°C) Typ (+25°C) Typ (+25°C)© 2006 Microchip Technology Inc. DS39564C-page 299 PIC18FXX2 FIGURE 23-21: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 5V, -40°C TO +125°C) FIGURE 23-22: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 3V, -40°C TO +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0 5 10 15 20 25 IOH (-mA) VOH (V) Typ (25C) Max Min Max Typ (+25°C) Min 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 5 10 15 20 25 IOH (-mA) VOH (V) Typ (25C) Max Min Typ (+25°C) Min MaxPIC18FXX2 DS39564C-page 300 © 2006 Microchip Technology Inc. FIGURE 23-23: TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 5V, -40°C TO +125°C) FIGURE 23-24: TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 3V, -40°C TO +125°C) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 0 5 10 15 20 25 IOL (-mA) VOL (V) Max Typ (25C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) Typ (+25°C) Max 0.0 0.5 1.0 1.5 2.0 2.5 0 5 10 15 20 25 IOL (-mA) VOL (V) Max Typ (25C) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) Typ (+25°C) Max© 2006 Microchip Technology Inc. DS39564C-page 301 PIC18FXX2 FIGURE 23-25: MINIMUM AND MAXIMUM VIN vs. VDD (ST INPUT, -40°C TO +125°C) FIGURE 23-26: MINIMUM AND MAXIMUM VIN vs. VDD (TTL INPUT, -40°C TO +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) VIN (V) VIH Max VIH Min VIL Max VIL Min Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) VIN (V) VTH (Max) VTH (Min) Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C)PIC18FXX2 DS39564C-page 302 © 2006 Microchip Technology Inc. FIGURE 23-27: MINIMUM AND MAXIMUM VIN vs. VDD (I2C INPUT, -40°C TO +125°C) FIGURE 23-28: A/D NON-LINEARITY vs. VREFH (VDD = VREFH, -40°C TO +125°C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (V) VIN (V) VIH Max VIH Min VILMax VIL Min Typical: statistical mean @ 25°C Maximum: mean + 3σ (-40°C to 125°C) Minimum: mean – 3σ (-40°C to 125°C) 0 0.5 1 1.5 2 2.5 3 3.5 4 2 2.5 3 3.5 4 4.5 5 5.5 VDD and VREFH (V) Differential or Integral Nonlinearity (LSB) -40C 25C 85C 125C -40°C +25°C +85°C +125°C© 2006 Microchip Technology Inc. DS39564C-page 303 PIC18FXX2 FIGURE 23-29: A/D NON-LINEARITY vs. VREFH (VDD = 5V, -40°C TO +125°C) 0 0.5 1 1.5 2 2.5 3 2 2.5 3 3.5 4 4.5 5 5.5 VREFH (V) Differential or Integral Nonlinearilty (LSB) Max (-40C to 125C) Typ (+25°C) Typ (25C) Max (-40°C to +125°C)PIC18FXX2 DS39564C-page 304 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 305 PIC18FXX2 24.0 PACKAGING INFORMATION 24.1 Package Marking Information 28-Lead SPDIP XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F242-I/SP 0610017 28-Lead SOIC XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F242-E/SO 0610017 40-Lead PDIP XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX YYWWNNN Example PIC18F442-I/P 0610017 Legend: XX...X Customer-specific information Y Year code (last digit of calendar year) YY Year code (last 2 digits of calendar year) WW Week code (week of January 1 is week ‘01’) NNN Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) * This package is Pb-free. The Pb-free JEDEC designator ( ) can be found on the outer packaging for this package. Note: In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. e3 e3 e3 e3 e3PIC18FXX2 DS39564C-page 306 © 2006 Microchip Technology Inc. Package Marking Information (Cont’d) 44-Lead TQFP XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN Example PIC18F452 -E/PT 0610017 44-Lead PLCC XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN Example PIC18F442 -I/L 0610017 e3 e3© 2006 Microchip Technology Inc. DS39564C-page 307 PIC18FXX2 24.2 Package Details The following sections give the technical details of the packages. 28-Lead Skinny Plastic Dual In-line (SP) – 300 mil Body (PDIP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Mold Draft Angle Bottom β 5 10 15 5 10 15 Mold Draft Angle Top α 5 10 15 5 10 15 Overall Row Spacing § eB .320 .350 .430 8.13 8.89 10.92 Lower Lead Width B .016 .019 .022 0.41 0.48 0.56 Upper Lead Width B1 .040 .053 .065 1.02 1.33 1.65 Lead Thickness c .008 .012 .015 0.20 0.29 0.38 Tip to Seating Plane L .125 .130 .135 3.18 3.30 3.43 Overall Length D 1.345 1.365 1.385 34.16 34.67 35.18 Molded Package Width E1 .275 .285 .295 6.99 7.24 7.49 Shoulder to Shoulder Width E .300 .310 .325 7.62 7.87 8.26 Base to Seating Plane A1 .015 0.38 Molded Package Thickness A2 .125 .130 .135 3.18 3.30 3.43 Top to Seating Plane A .140 .150 .160 3.56 3.81 4.06 Pitch p .100 2.54 Number of Pins n 28 28 Dimension Limits MIN NOM MAX MIN NOM MAX Units INCHES* MILLIMETERS 2 1 D n E1 c eB β E α p L A2 B B1 A A1 Notes: JEDEC Equivalent: MO-095 Drawing No. C04-070 * Controlling Parameter Dimension D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side. § Significant CharacteristicPIC18FXX2 DS39564C-page 308 © 2006 Microchip Technology Inc. 28-Lead Plastic Small Outline (SO) – Wide, 300 mil Body (SOIC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Foot Angle Top φ 048048 Mold Draft Angle Bottom β 0 12 15 0 12 15 Mold Draft Angle Top α 0 12 15 0 12 15 Lead Width B .014 .017 .020 0.36 0.42 0.51 Lead Thickness c .009 .011 .013 0.23 0.28 0.33 Foot Length L .016 .033 .050 0.41 0.84 1.27 Chamfer Distance h .010 .020 .029 0.25 0.50 0.74 Overall Length D .695 .704 .712 17.65 17.87 18.08 Molded Package Width E1 .288 .295 .299 7.32 7.49 7.59 Overall Width E .394 .407 .420 10.01 10.34 10.67 Standoff § A1 .004 .008 .012 0.10 0.20 0.30 Molded Package Thickness A2 .088 .091 .094 2.24 2.31 2.39 Overall Height A .093 .099 .104 2.36 2.50 2.64 Pitch p .050 1.27 Number of Pins n 28 28 Dimension Limits MIN NOM MAX MIN NOM MAX Units INCHES* MILLIMETERS 2 1 D p n B E E1 L c β 45° h φ A2 α A A1 * Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side. JEDEC Equivalent: MS-013 Drawing No. C04-052 § Significant Characteristic© 2006 Microchip Technology Inc. DS39564C-page 309 PIC18FXX2 40-Lead Plastic Dual In-line (P) – 600 mil Body (PDIP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Mold Draft Angle Bottom β 5 10 15 5 10 15 Mold Draft Angle Top α 5 10 15 5 10 15 Overall Row Spacing § eB .620 .650 .680 15.75 16.51 17.27 Lower Lead Width B .014 .018 .022 0.36 0.46 0.56 Upper Lead Width B1 .030 .050 .070 0.76 1.27 1.78 Lead Thickness c .008 .012 .015 0.20 0.29 0.38 Tip to Seating Plane L .120 .130 .135 3.05 3.30 3.43 Overall Length D 2.045 2.058 2.065 51.94 52.26 52.45 Molded Package Width E1 .530 .545 .560 13.46 13.84 14.22 Shoulder to Shoulder Width E .595 .600 .625 15.11 15.24 15.88 Base to Seating Plane A1 .015 0.38 Molded Package Thickness A2 .140 .150 .160 3.56 3.81 4.06 Top to Seating Plane A .160 .175 .190 4.06 4.45 4.83 Pitch p .100 2.54 Number of Pins n 40 40 Dimension Limits MIN NOM MAX MIN NOM MAX Units INCHES* MILLIMETERS A2 1 2 D n E1 c β eB E α p L B B1 A A1 * Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side. JEDEC Equivalent: MO-011 Drawing No. C04-016 § Significant CharacteristicPIC18FXX2 DS39564C-page 310 © 2006 Microchip Technology Inc. 44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging F A A1 A2 α E E1 #leads=n1 p B D1 D n 1 2 φ c β L CH x 45° Pin 1 Corner Chamfer CH .025 .035 .045 0.64 0.89 1.14 Footprint (Reference) F .039 REF. 1.00 REF. Units INCHES MILLIMETERS* Dimension Limits MIN NOM MAX MIN NOM MAX Number of Pins n 44 44 Pitch p .031 0.80 Overall Height A .039 .043 .047 1.00 1.10 1.20 Molded Package Thickness A2 .037 .039 .041 0.95 1.00 1.05 Standoff A1 .002 .004 .006 0.05 0.10 0.15 Foot Length L .018 .024 .030 0.45 0.60 0.75 Foot Angle φ 0 3.5 7 0 3.5 7 Overall Width E .463 .472 .482 11.75 12.00 12.25 Overall Length D .463 .472 .482 11.75 12.00 12.25 Molded Package Width E1 .390 .394 .398 9.90 10.00 10.10 Molded Package Length D1 .390 .394 .398 9.90 10.00 10.10 Pins per Side n1 11 11 Lead Thickness c .004 .006 .008 0.09 0.15 0.20 Lead Width B .012 .015 .017 0.30 0.38 0.44 Mold Draft Angle Top α 5 10 15 5 10 15 Mold Draft Angle Bottom β 5 10 15 5 10 15 Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. Notes: JEDEC Equivalent: MS-026 Revised 07-22-05 * Controlling Parameter REF: Reference Dimension, usually without tolerance, for information purposes only. See ASME Y14.5M Drawing No. C04-076© 2006 Microchip Technology Inc. DS39564C-page 311 PIC18FXX2 44-Lead Plastic Leaded Chip Carrier (L) – Square (PLCC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging CH2 x 45° CH1 x 45° Mold Draft Angle Bottom β 0 5 10 0 5 10 Mold Draft Angle Top α 0 5 10 0 5 10 B .013 .020 .021 0.33 0.51 0.53 Upper Lead Width B1 .026 .029 .032 0.66 0.74 0.81 Lead Thickness c .008 .011 .013 0.20 0.27 0.33 Pins per Side n1 11 11 Footprint Length D2 .590 .620 .630 14.99 15.75 16.00 Footprint Width E2 .590 .620 .630 14.99 15.75 16.00 Molded Package Length D1 .650 .653 .656 16.51 16.59 16.66 Molded Package Width E1 .650 .653 .656 16.51 16.59 16.66 Overall Length D .685 .690 .695 17.40 17.53 17.65 Overall Width E .685 .690 .695 17.40 17.53 17.65 Corner Chamfer (others) CH2 .000 .005 .010 0.00 0.13 0.25 Corner Chamfer 1 CH1 .040 .045 .050 1.02 1.14 1.27 Side 1 Chamfer Height A3 .024 .029 .034 0.61 0.74 0.86 Standoff § A1 .020 0.51 Molded Package Thickness A2 Overall Height A .165 .173 .180 4.19 4.39 4.57 Pitch p .050 1.27 Number of Pins n 44 44 Dimension Limits MIN NOM MAX MIN NOM MAX Units INCHES* MILLIMETERS β A2 c E2 2 D1 D n #leads=n1 E E1 1 α p A3 A 35° B1 B D2 A1 .145 .153 .160 3.68 3.87 4.06 .028 .035 0.71 0.89 Lower Lead Width * Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side. JEDEC Equivalent: MO-047 Drawing No. C04-048 § Significant CharacteristicPIC18FXX2 DS39564C-page 312 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 313 PIC18FXX2 APPENDIX A: REVISION HISTORY Revision A (June 2001) Original data sheet for the PIC18FXX2 family. Revision B (August 2002) This revision includes the DC and AC Characteristics Graphs and Tables. The Electrical Specifications in Section 22.0 have been updated and there have been minor corrections to the data sheet text. Revision C (October 2006) Packaging diagrams updated. APPENDIX B: DEVICE DIFFERENCES The differences between the devices listed in this data sheet are shown in Table B-1. TABLE B-1: DEVICE DIFFERENCES Feature PIC18F242 PIC18F252 PIC18F442 PIC18F452 Program Memory (Kbytes) 16 32 16 32 Data Memory (Bytes) 768 1536 768 1536 A/D Channels 5 5 8 8 Parallel Slave Port (PSP) No No Yes Yes Package Types 28-pin DIP 28-pin SOIC 28-pin DIP 28-pin SOIC 40-pin DIP 44-pin PLCC 44-pin TQFP 40-pin DIP 44-pin PLCC 44-pin TQFPPIC18FXX2 DS39564C-page 314 © 2006 Microchip Technology Inc. APPENDIX C: CONVERSION CONSIDERATIONS This appendix discusses the considerations for converting from previous versions of a device to the ones listed in this data sheet. Typically, these changes are due to the differences in the process technology used. An example of this type of conversion is from a PIC16C74A to a PIC16C74B. Not Applicable APPENDIX D: MIGRATION FROM BASELINE TO ENHANCED DEVICES This section discusses how to migrate from a Baseline device (i.e., PIC16C5X) to an Enhanced MCU device (i.e., PIC18FXXX). The following are the list of modifications over the PIC16C5X microcontroller family: Not Currently Available© 2006 Microchip Technology Inc. DS39564C-page 315 PIC18FXX2 APPENDIX E: MIGRATION FROM MID-RANGE TO ENHANCED DEVICES A detailed discussion of the differences between the mid-range MCU devices (i.e., PIC16CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN716, “Migrating Designs from PIC16C74A/74B to PIC18F442”. The changes discussed, while device specific, are generally applicable to all mid-range to enhanced device migrations. This Application Note is available as Literature Number DS00716. APPENDIX F: MIGRATION FROM HIGH-END TO ENHANCED DEVICES A detailed discussion of the migration pathway and differences between the high-end MCU devices (i.e., PIC17CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN726, “PIC17CXXX to PIC18FXXX Migration”. This Application Note is available as Literature Number DS00726.PIC18FXX2 DS39564C-page 316 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 317 PIC18FXX2 INDEX A A/D ................................................................................... 181 A/D Converter Flag (ADIF Bit) ................................. 183 A/D Converter Interrupt, Configuring ....................... 184 Acquisition Requirements ........................................ 184 ADCON0 Register .................................................... 181 ADCON1 Register .................................................... 181 ADRESH Register .................................................... 181 ADRESH/ADRESL Registers .................................. 183 ADRESL Register .................................................... 181 Analog Port Pins ................................................ 99, 100 Analog Port Pins, Configuring .................................. 186 Associated Registers ............................................... 188 Configuring the Module ............................................ 184 Conversion Clock (TAD) ........................................... 186 Conversion Status (GO/DONE Bit) .......................... 183 Conversions ............................................................. 187 Converter Characteristics ........................................ 287 Equations Acquisition Time ............................................... 185 Minimum Charging Time .................................. 185 Examples Calculating the Minimum Required Acquisition Time ...................................... 185 Result Registers ....................................................... 187 Special Event Trigger (CCP) ............................ 120, 188 TAD vs. Device Operating Frequencies .................... 186 Use of the CCP2 Trigger .......................................... 188 Absolute Maximum Ratings ............................................. 259 AC (Timing) Characteristics ............................................. 269 Load Conditions for Device Timing Specifications ................................................... 270 Parameter Symbology ............................................. 269 Temperature and Voltage Specifications - AC ......... 270 Timing Conditions .................................................... 270 ACKSTAT Status Flag ..................................................... 155 ADCON0 Register ............................................................ 181 GO/DONE Bit ........................................................... 183 ADCON1 Register ............................................................ 181 ADDLW ............................................................................ 217 ADDWF ............................................................................ 217 ADDWFC ......................................................................... 218 ADRESH Register ............................................................ 181 ADRESH/ADRESL Registers ........................................... 183 ADRESL Register ............................................................ 181 Analog-to-Digital Converter. See A/D ANDLW ............................................................................ 218 ANDWF ............................................................................ 219 Assembler MPASM Assembler .................................................. 253 B Baud Rate Generator ....................................................... 151 BC .................................................................................... 219 BCF .................................................................................. 220 BF Status Flag ................................................................. 155 Block Diagrams A/D Converter .......................................................... 183 Analog Input Model .................................................. 184 Baud Rate Generator .............................................. 151 Capture Mode Operation ......................................... 119 Compare Mode Operation ....................................... 120 Low Voltage Detect External Reference Source ............................. 190 Internal Reference Source ............................... 190 MSSP I 2C Mode ......................................................... 134 MSSP (SPI Mode) ................................................... 125 On-Chip Reset Circuit ................................................ 25 Parallel Slave Port (PORTD and PORTE) ............... 100 PIC18F2X2 .................................................................. 8 PIC18F4X2 .................................................................. 9 PLL ............................................................................ 19 PORTC (Peripheral Output Override) ........................ 93 PORTD (I/O Mode) .................................................... 95 PORTE (I/O Mode) .................................................... 97 PWM Operation (Simplified) .................................... 122 RA3:RA0 and RA5 Port Pins ..................................... 87 RA4/T0CKI Pin .......................................................... 88 RA6 Pin ..................................................................... 88 RB2:RB0 Port Pins .................................................... 91 RB3 Pin ..................................................................... 91 RB7:RB4 Port Pins .................................................... 90 Table Read Operation ............................................... 55 Table Write Operation ................................................ 56 Table Writes to FLASH Program Memory ................. 61 Timer0 in 16-bit Mode .............................................. 104 Timer0 in 8-bit Mode ................................................ 104 Timer1 ..................................................................... 108 Timer1 (16-bit R/W Mode) ....................................... 108 Timer2 ..................................................................... 112 Timer3 ..................................................................... 114 Timer3 (16-bit R/W Mode) ....................................... 114 USART Asynchronous Receive .................................... 174 Asynchronous Transmit ................................... 172 Watchdog Timer ...................................................... 204 BN .................................................................................... 220 BNC ................................................................................. 221 BNN ................................................................................. 221 BNOV ............................................................................... 222 BNZ .................................................................................. 222 BOR. See Brown-out Reset BOV ................................................................................. 225 BRA ................................................................................. 223 BRG. See Baud Rate Generator Brown-out Reset (BOR) ..................................................... 26 BSF .................................................................................. 223 BTFSC ............................................................................. 224 BTFSS ............................................................................. 224 BTG ................................................................................. 225 Bus Collision During a STOP Condition .......................... 163 BZ .................................................................................... 226PIC18FXX2 DS39564C-page 318 © 2006 Microchip Technology Inc. C CALL ................................................................................ 226 Capture (CCP Module) ..................................................... 119 Associated Registers ...............................................121 CCP Pin Configuration ............................................. 119 CCPR1H:CCPR1L Registers ................................... 119 Software Interrupt ..................................................... 119 Timer1/Timer3 Mode Selection ................................ 119 Capture/Compare/PWM (CCP) ........................................ 117 Capture Mode. See Capture CCP1 ........................................................................118 CCPR1H Register ............................................ 118 CCPR1L Register ............................................ 118 CCP2 ........................................................................118 CCPR2H Register ............................................ 118 CCPR2L Register ............................................ 118 Compare Mode. See Compare Interaction of Two CCP Modules ............................. 118 PWM Mode. See PWM Timer Resources ...................................................... 118 Clocking Scheme/Instruction Cycle .................................... 39 CLRF ................................................................................ 227 CLRWDT .......................................................................... 227 Code Examples 16 x 16 Signed Multiply Routine ................................. 72 16 x 16 Unsigned Multiply Routine ............................. 72 8 x 8 Signed Multiply Routine ..................................... 71 8 x 8 Unsigned Multiply Routine ................................. 71 Changing Between Capture Prescalers ................... 119 Data EEPROM Read .................................................67 Data EEPROM Refresh Routine ................................68 Data EEPROM Write .................................................. 67 Erasing a FLASH Program Memory Row .................. 60 Fast Register Stack .................................................... 39 How to Clear RAM (Bank1) Using Indirect Addressing ............................................ 50 Initializing PORTA ...................................................... 87 Initializing PORTB ...................................................... 90 Initializing PORTC ...................................................... 93 Initializing PORTD ...................................................... 95 Initializing PORTE ...................................................... 97 Loading the SSPBUF (SSPSR) Register ................. 128 Reading a FLASH Program Memory Word ................ 59 Saving STATUS, WREG and BSR Registers in RAM ............................................... 85 Writing to FLASH Program Memory ..................... 62–63 Code Protection ............................................................... 195 COMF ............................................................................... 228 Compare (CCP Module) ...................................................120 Associated Registers ...............................................121 CCP Pin Configuration ............................................. 120 CCPR1 Register ....................................................... 120 Software Interrupt ..................................................... 120 Special Event Trigger ........................109, 115, 120, 188 Timer1/Timer3 Mode Selection ................................ 120 Configuration Bits ............................................................. 195 Context Saving During Interrupts ....................................... 85 Conversion Considerations .............................................. 314 CPFSEQ .......................................................................... 228 CPFSGT ........................................................................... 229 CPFSLT ........................................................................... 229 D Data EEPROM Memory Associated Registers ................................................. 69 EEADR Register ........................................................ 65 EECON1 Register ...................................................... 65 EECON2 Register ...................................................... 65 Operation During Code Protect ................................. 68 Protection Against Spurious Write ............................. 68 Reading ..................................................................... 67 Using .......................................................................... 68 Write Verify ................................................................ 68 Writing ........................................................................ 67 Data Memory ..................................................................... 42 General Purpose Registers ....................................... 42 Map for PIC18F242/442 ............................................ 43 Map for PIC18F252/452 ............................................ 44 Special Function Registers ........................................ 42 DAW ................................................................................ 230 DC and AC Characteristics Graphs and Tables .................................................. 289 DC Characteristics ....................................................261, 265 DCFSNZ .......................................................................... 231 DECF ............................................................................... 230 DECFSZ .......................................................................... 231 Development Support ...................................................... 253 Device Differences ........................................................... 313 Device Overview .................................................................. 7 Features ....................................................................... 7 Direct Addressing ............................................................... 51 Example ..................................................................... 49 E Electrical Characteristics .................................................. 259 Errata ................................................................................... 5 F Firmware Instructions ....................................................... 211 FLASH Program Memory ................................................... 55 Associated Registers ................................................. 63 Control Registers ....................................................... 56 Erase Sequence ........................................................ 60 Erasing ....................................................................... 60 Operation During Code Protect ................................. 63 Reading ..................................................................... 59 TABLAT Register ....................................................... 58 Table Pointer ............................................................. 58 Boundaries Based on Operation ........................ 58 Table Pointer Boundaries .......................................... 58 Table Reads and Table Writes .................................. 55 Block Diagrams Reads from FLASH Program Memory ....... 59 Writing to .................................................................... 61 Protection Against Spurious Writes ................... 63 Unexpected Termination .................................... 63 Write Verify ........................................................ 63 G General Call Address Support ......................................... 148 GOTO .............................................................................. 232© 2006 Microchip Technology Inc. DS39564C-page 319 PIC18FXX2 I I/O Ports ............................................................................. 87 I 2C (MSSP Module) ACK Pulse ................................................................ 139 Read/Write Bit Information (R/W Bit) ....................... 139 I 2C (SSP Module) ACK Pulse ................................................................ 138 I 2C Master Mode Reception ............................................. 155 I 2C Mode Clock Stretching ....................................................... 144 I 2C Mode (MSSP Module) ................................................ 134 Registers .................................................................. 134 I 2C Module ACK Pulse ........................................................ 138, 139 Acknowledge Sequence Timing ............................... 158 Baud Rate Generator ............................................... 151 Bus Collision Repeated START Condition ............................ 162 START Condition ............................................. 160 Clock Arbitration ....................................................... 152 Effect of a RESET .................................................... 159 General Call Address Support ................................. 148 Master Mode ............................................................ 149 Operation ......................................................... 150 Repeated START Condition Timing ................. 154 Master Mode START Condition ............................... 153 Master Mode Transmission ...................................... 155 Multi-Master Communication, Bus Collision and Arbitration .................................................. 159 Multi-Master Mode ................................................... 159 Operation ................................................................. 138 Read/Write Bit Information (R/W Bit) ............... 138, 139 Serial Clock (RC3/SCK/SCL) ................................... 139 Slave Mode .............................................................. 138 Addressing ....................................................... 138 Reception ......................................................... 139 Transmission .................................................... 139 Slave Mode Timing (10-bit Reception, SEN = 0) .......................................................... 142 Slave Mode Timing (10-bit Reception, SEN = 1) .......................................................... 147 Slave Mode Timing (10-bit Transmission) ................ 143 Slave Mode Timing (7-bit Reception, SEN = 0) .......................................................... 140 Slave Mode Timing (7-bit Reception, SEN = 1) .......................................................... 146 Slave Mode Timing (7-bit Transmission) .................. 141 SLEEP Operation ..................................................... 159 STOP Condition Timing ........................................... 158 ICEPIC In-Circuit Emulator .............................................. 254 ID Locations ............................................................. 195, 210 INCF ................................................................................. 232 INCFSZ ............................................................................ 233 In-Circuit Debugger .......................................................... 210 In-Circuit Serial Programming (ICSP) ...................... 195, 210 Indirect Addressing ............................................................ 51 INDF and FSR Registers ........................................... 50 Indirect Addressing Operation ............................................ 51 Indirect File Operand .......................................................... 42 INFSNZ ............................................................................ 233 Instruction Cycle ................................................................. 39 Instruction Flow/Pipelining ................................................. 40 Instruction Format ............................................................ 213 Instruction Set .................................................................. 211 ADDLW .................................................................... 217 ADDWF .................................................................... 217 ADDWFC ................................................................. 218 ANDLW .................................................................... 218 ANDWF .................................................................... 219 BC ............................................................................ 219 BCF ......................................................................... 220 BN ............................................................................ 220 BNC ......................................................................... 221 BNN ......................................................................... 221 BNOV ...................................................................... 222 BNZ ......................................................................... 222 BOV ......................................................................... 225 BRA ......................................................................... 223 BSF .......................................................................... 223 BTFSC ..................................................................... 224 BTFSS ..................................................................... 224 BTG ......................................................................... 225 BZ ............................................................................ 226 CALL ........................................................................ 226 CLRF ....................................................................... 227 CLRWDT ................................................................. 227 COMF ...................................................................... 228 CPFSEQ .................................................................. 228 CPFSGT .................................................................. 229 CPFSLT ................................................................... 229 DAW ........................................................................ 230 DCFSNZ .................................................................. 231 DECF ....................................................................... 230 DECFSZ .................................................................. 231 GOTO ...................................................................... 232 INCF ........................................................................ 232 INCFSZ .................................................................... 233 INFSNZ .................................................................... 233 IORLW ..................................................................... 234 IORWF ..................................................................... 234 LFSR ....................................................................... 235 MOVF ...................................................................... 235 MOVFF .................................................................... 236 MOVLB .................................................................... 236 MOVLW ................................................................... 237 MOVWF ................................................................... 237 MULLW .................................................................... 238 MULWF .................................................................... 238 NEGF ....................................................................... 239 NOP ......................................................................... 239 POP ......................................................................... 240 PUSH ....................................................................... 240 RCALL ..................................................................... 241 RESET ..................................................................... 241 RETFIE .................................................................... 242 RETLW .................................................................... 242 RETURN .................................................................. 243 RLCF ....................................................................... 243 RLNCF ..................................................................... 244 RRCF ....................................................................... 244 RRNCF .................................................................... 245 SETF ....................................................................... 245 SLEEP ..................................................................... 246 SUBFWB ................................................................. 246 SUBLW .................................................................... 247 SUBWF .................................................................... 247 SUBWFB ................................................................. 248 SWAPF .................................................................... 248PIC18FXX2 DS39564C-page 320 © 2006 Microchip Technology Inc. TBLRD ..................................................................... 249 TBLWT ..................................................................... 250 TSTFSZ ....................................................................251 XORLW ....................................................................251 XORWF ....................................................................252 Summary Table ........................................................ 214 Instructions in Program Memory ........................................ 40 Two-Word Instructions ............................................... 41 INT Interrupt (RB0/INT). See Interrupt Sources INTCON Register RBIF Bit ......................................................................90 INTCON Registers ....................................................... 75–77 Inter-Integrated Circuit. See I2C Interrupt Sources .............................................................. 195 A/D Conversion Complete ........................................ 184 Capture Complete (CCP) ......................................... 119 Compare Complete (CCP) ....................................... 120 INT0 ........................................................................... 85 Interrupt-on-Change (RB7:RB4 ) ............................... 90 PORTB, Interrupt-on-Change .................................... 85 RB0/INT Pin, External ................................................ 85 TMR0 ......................................................................... 85 TMR0 Overflow ........................................................ 105 TMR1 Overflow ................................................ 107, 109 TMR2 to PR2 Match .................................................112 TMR2 to PR2 Match (PWM) ............................ 111, 122 TMR3 Overflow ................................................ 113, 115 USART Receive/Transmit Complete ........................ 165 Interrupts ............................................................................ 73 Logic ........................................................................... 74 Interrupts, Enable Bits CCP1 Enable (CCP1IE Bit) ...................................... 119 Interrupts, Flag Bits A/D Converter Flag (ADIF Bit) .................................. 183 CCP1 Flag (CCP1IF Bit) .......................................... 119 CCP1IF Flag (CCP1IF Bit) ....................................... 120 Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ........................................................... 90 IORLW ............................................................................. 234 IORWF ............................................................................. 234 IPR Registers ............................................................... 82–83 K KEELOQ Evaluation and Programming Tools ................... 256 L LFSR ................................................................................ 235 Lookup Tables Computed GOTO ....................................................... 41 Table Reads, Table Writes ......................................... 41 Low Voltage Detect .......................................................... 189 Converter Characteristics ......................................... 267 Effects of a RESET .................................................. 193 Operation ................................................................. 192 Current Consumption ....................................... 193 During SLEEP .................................................. 193 Reference Voltage Set Point ............................193 Typical Application ...................................................189 LVD. See Low Voltage Detect. ......................................... 189 M Master SSP (MSSP) Module Overview ........................... 125 Master Synchronous Serial Port (MSSP). See MSSP. Master Synchronous Serial Port. See MSSP Memory Organization Data Memory ............................................................. 42 Program Memory ....................................................... 35 Memory Programming Requirements .............................. 268 Migration from Baseline to Enhanced Devices ................ 314 Migration from High-End to Enhanced Devices ............... 315 Migration from Mid-Range to Enhanced Devices ............ 315 MOVF .............................................................................. 235 MOVFF ............................................................................ 236 MOVLB ............................................................................ 236 MOVLW ........................................................................... 237 MOVWF ........................................................................... 237 MPLAB C17 and MPLAB C18 C Compilers ..................... 253 MPLAB ICD In-Circuit Debugger ..................................... 255 MPLAB ICE High Performance Universal In-Circuit Emulator with MPLAB IDE ....................................... 254 MPLAB Integrated Development Environment Software ............................................. 253 MPLINK Object Linker/MPLIB Object Librarian ............... 254 MSSP ............................................................................... 125 Control Registers (general) ...................................... 125 Enabling SPI I/O ...................................................... 129 Operation ................................................................. 128 Typical Connection .................................................. 129 MSSP Module SPI Master Mode ..................................................... 130 SPI Master./Slave Connection ................................. 129 SPI Slave Mode ....................................................... 131 MULLW ............................................................................ 238 MULWF ............................................................................ 238 N NEGF ............................................................................... 239 NOP ................................................................................. 239 O Opcode Field Descriptions ............................................... 212 OPTION_REG Register PSA Bit .................................................................... 105 T0CS Bit .................................................................. 105 T0PS2:T0PS0 Bits ................................................... 105 T0SE Bit ................................................................... 105 Oscillator Configuration ...................................................... 17 EC .............................................................................. 17 ECIO .......................................................................... 17 HS .............................................................................. 17 HS + PLL ................................................................... 17 LP .............................................................................. 17 RC .............................................................................. 17 RCIO .......................................................................... 17 XT .............................................................................. 17 Oscillator Selection .......................................................... 195 Oscillator, Timer1 ..............................................107, 109, 115 Oscillator, Timer3 ............................................................. 113 Oscillator, WDT ................................................................ 203© 2006 Microchip Technology Inc. DS39564C-page 321 PIC18FXX2 P Packaging ........................................................................ 305 Details ...................................................................... 307 Marking Information ................................................. 305 Parallel Slave Port PORTD .................................................................... 100 Parallel Slave Port (PSP) ........................................... 95, 100 Associated Registers ............................................... 101 RE0/RD/AN5 Pin ................................................ 99, 100 RE1/WR/AN6 Pin ............................................... 99, 100 RE2/CS/AN7 Pin ................................................ 99, 100 Select (PSPMODE Bit) ...................................... 95, 100 PIC18F2X2 Pin Functions MCLR/VPP .................................................................. 10 OSC1/CLKI ................................................................ 10 OSC2/CLKO/RA6 ...................................................... 10 RA0/AN0 .................................................................... 10 RA1/AN1 .................................................................... 10 RA2/AN2/VREF- .......................................................... 10 RA3/AN3/VREF+ ......................................................... 10 RA4/T0CKI ................................................................. 10 RA5/AN4/SS/LVDIN ................................................... 10 RB0/INT0 ................................................................... 11 RB1/INT1 ................................................................... 11 RB2/INT2 ................................................................... 11 RB3/CCP2 ................................................................. 11 RB4 ............................................................................ 11 RB5/PGM ................................................................... 11 RB6/PGC ................................................................... 11 RB7/PGD ................................................................... 11 RC0/T1OSO/T1CKI ................................................... 12 RC1/T1OSI/CCP2 ...................................................... 12 RC2/CCP1 ................................................................. 12 RC3/SCK/SCL ........................................................... 12 RC4/SDI/SDA ............................................................ 12 RC5/SDO ................................................................... 12 RC6/TX/CK ................................................................ 12 RC7/RX/DT ................................................................ 12 VDD ............................................................................. 12 VSS ............................................................................. 12 PIC18F4X2 Pin Functions MCLR/VPP .................................................................. 13 OSC1/CLKI ................................................................ 13 OSC2/CLKO .............................................................. 13 RA0/AN0 .................................................................... 13 RA1/AN1 .................................................................... 13 RA2/AN2/VREF- .......................................................... 13 RA3/AN3/VREF+ ......................................................... 13 RA4/T0CKI ................................................................. 13 RA5/AN4/SS/LVDIN ................................................... 13 RB0/INT ..................................................................... 14 RB1 ............................................................................ 14 RB2 ............................................................................ 14 RB3 ............................................................................ 14 RB4 ............................................................................ 14 RB5/PGM ................................................................... 14 RB6/PGC ................................................................... 14 RB7/PGD ................................................................... 14 RC0/T1OSO/T1CKI ................................................... 15 RC1/T1OSI/CCP2 ...................................................... 15 RC2/CCP1 ................................................................. 15 RC3/SCK/SCL ........................................................... 15 RC4/SDI/SDA ............................................................ 15 RC5/SDO ................................................................... 15 RC6/TX/CK ................................................................ 15 RC7/RX/DT ................................................................ 15 RD0/PSP0 ................................................................. 16 RD1/PSP1 ................................................................. 16 RD2/PSP2 ................................................................. 16 RD3/PSP3 ................................................................. 16 RD4/PSP4 ................................................................. 16 RD5/PSP5 ................................................................. 16 RD6/PSP6 ................................................................. 16 RD7/PSP7 ................................................................. 16 RE0/RD/AN5 .............................................................. 16 RE1/WR/AN6 ............................................................. 16 RE2/CS/AN7 .............................................................. 16 VDD ............................................................................ 16 VSS ............................................................................ 16 PIC18FXX2 Voltage-Frequency Graph (Industrial) ................................................................ 260 PIC18LFXX2 Voltage-Frequency Graph (Industrial) ................................................................ 260 PICDEM 1 Low Cost PICmicro Demonstration Board ............................................... 255 PICDEM 17 Demonstration Board ................................... 256 PICDEM 2 Low Cost PIC16CXX Demonstration Board ............................................... 255 PICDEM 3 Low Cost PIC16CXXX Demonstration Board ............................................... 256 PICSTART Plus Entry Level Development Programmer ............................................................. 255 PIE Registers ................................................................80–81 Pinout I/O Descriptions PIC18F2X2 ................................................................ 10 PIR Registers ................................................................78–79 PLL Lock Time-out ............................................................. 26 Pointer, FSR ...................................................................... 50 POP ................................................................................. 240 POR. See Power-on Reset PORTA Associated Registers ................................................. 89 LATA Register ........................................................... 87 PORTA Register ........................................................ 87 TRISA Register .......................................................... 87 PORTB Associated Registers ................................................. 92 LATB Register ........................................................... 90 PORTB Register ........................................................ 90 RB0/INT Pin, External ................................................ 85 RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) .......... 90 TRISB Register .......................................................... 90 PORTC Associated Registers ................................................. 94 LATC Register ........................................................... 93 PORTC Register ........................................................ 93 RC3/SCK/SCL Pin ................................................... 139 RC7/RX/DT Pin ........................................................ 168 TRISC Register ...................................................93, 165 PORTD Associated Registers ................................................. 96 LATD Register ........................................................... 95 Parallel Slave Port (PSP) Function ............................ 95 PORTD Register ........................................................ 95 TRISD Register .......................................................... 95PIC18FXX2 DS39564C-page 322 © 2006 Microchip Technology Inc. PORTE Analog Port Pins ................................................ 99, 100 Associated Registers .................................................99 LATE Register ............................................................ 97 PORTE Register ........................................................ 97 PSP Mode Select (PSPMODE Bit) .................... 95, 100 RE0/RD/AN5 Pin ................................................ 99, 100 RE1/WR/AN6 Pin ............................................... 99, 100 RE2/CS/AN7 Pin ................................................ 99, 100 TRISE Register .......................................................... 97 Postscaler, WDT Assignment (PSA Bit) ...............................................105 Rate Select (T0PS2:T0PS0 Bits) ............................. 105 Switching Between Timer0 and WDT ...................... 105 Power-down Mode. See SLEEP Power-on Reset (POR) ...................................................... 26 Oscillator Start-up Timer (OST) ................................. 26 Power-up Timer (PWRT) ............................................ 26 Prescaler, Capture ........................................................... 119 Prescaler, Timer0 ............................................................. 105 Assignment (PSA Bit) ...............................................105 Rate Select (T0PS2:T0PS0 Bits) ............................. 105 Switching Between Timer0 and WDT ...................... 105 Prescaler, Timer2 ............................................................. 122 PRO MATE II Universal Device Programmer ................... 255 Product Identification System ........................................... 327 Program Counter PCL Register .............................................................. 39 PCLATH Register ....................................................... 39 PCLATU Register ....................................................... 39 Program Memory Interrupt Vector .......................................................... 35 Map and Stack for PIC18F442/242 ............................36 Map and Stack for PIC18F452/252 ............................36 RESET Vector ............................................................ 35 Program Verification and Code Protection ....................... 207 Associated Registers ...............................................207 Programming, Device Instructions ................................... 211 PSP.See Parallel Slave Port. Pulse Width Modulation. See PWM (CCP Module). PUSH ............................................................................... 240 PWM (CCP Module) ......................................................... 122 Associated Registers ...............................................123 CCPR1H:CCPR1L Registers ................................... 122 Duty Cycle ................................................................ 122 Example Frequencies/Resolutions ........................... 123 Period ....................................................................... 122 Setup for PWM Operation ........................................ 123 TMR2 to PR2 Match ......................................... 111, 122 Q Q Clock ............................................................................ 122 R RAM. See Data Memory RC Oscillator ......................................................................18 RCALL .............................................................................. 241 RCSTA Register SPEN Bit .................................................................. 165 Register File ....................................................................... 42 Registers ADCON0 (A/D Control 0) ......................................... 181 ADCON1 (A/D Control 1) ......................................... 182 CCP1CON and CCP2CON (Capture/Compare/PWM Control) ................... 117 CONFIG1H (Configuration 1 High) .......................... 196 CONFIG2H (Configuration 2 High) .......................... 197 CONFIG2L (Configuration 2 Low) ........................... 197 CONFIG3H (Configuration 3 High) .......................... 198 CONFIG4L (Configuration 4 Low) ........................... 198 CONFIG5H (Configuration 5 High) .......................... 199 CONFIG5L (Configuration 5 Low) ........................... 199 CONFIG6H (Configuration 6 High) .......................... 200 CONFIG6L (Configuration 6 Low) ........................... 200 CONFIG7H (Configuration 7 High) .......................... 201 CONFIG7L (Configuration 7 Low) ........................... 201 DEVID1 (Device ID Register 1) ............................... 202 DEVID2 (Device ID Register 2) ............................... 202 EECON1 (Data EEPROM Control 1) ....................57, 66 File Summary ........................................................46–48 INTCON (Interrupt Control) ........................................ 75 INTCON2 (Interrupt Control 2) ................................... 76 INTCON3 (Interrupt Control 3) ................................... 77 IPR1 (Peripheral Interrupt Priority 1) ......................... 82 IPR2 (Peripheral Interrupt Priority 2) ......................... 83 LVDCON (LVD Control) ........................................... 191 OSCCON (Oscillator Control) .................................... 21 PIE1 (Peripheral Interrupt Enable 1) .......................... 80 PIE2 (Peripheral Interrupt Enable 2) .......................... 81 PIR1 (Peripheral Interrupt Request 1) ....................... 78 PIR2 (Peripheral Interrupt Request 2) ....................... 79 RCON (Register Control) ........................................... 84 RCON (RESET Control) ............................................ 53 RCSTA (Receive Status and Control) ..................... 167 SSPCON1 (MSSP Control 1) I 2C Mode ......................................................... 136 SPI Mode ......................................................... 127 SSPCON2 (MSSP Control 2) I 2C Mode ......................................................... 137 SSPSTAT (MSSP Status) I 2C Mode ......................................................... 135 SPI Mode ......................................................... 126 STATUS ..................................................................... 52 STKPTR (Stack Pointer) ............................................ 38 T0CON (Timer0 Control) ......................................... 103 T1CON (Timer 1 Control) ........................................ 107 T2CON (Timer 2 Control) ........................................ 111 T3CON (Timer3 Control) ......................................... 113 TRISE ........................................................................ 98 TXSTA (Transmit Status and Control) ..................... 166 WDTCON (Watchdog Timer Control) ...................... 203 RESET ................................................................25, 195, 241 Brown-out Reset (BOR) ........................................... 195 MCLR Reset (During SLEEP) .................................... 25 MCLR Reset (Normal Operation) .............................. 25 Oscillator Start-up Timer (OST) ............................... 195 Power-on Reset (POR) .......................................25, 195 Power-up Timer (PWRT) ......................................... 195 Programmable Brown-out Reset (BOR) .................... 25 RESET Instruction ..................................................... 25 Stack Full Reset ......................................................... 25 Stack Underflow Reset .............................................. 25 Watchdog Timer (WDT) Reset .................................. 25© 2006 Microchip Technology Inc. DS39564C-page 323 PIC18FXX2 RETFIE ............................................................................ 242 RETLW ............................................................................. 242 RETURN .......................................................................... 243 Revision History ............................................................... 313 RLCF ................................................................................ 243 RLNCF ............................................................................. 244 RRCF ............................................................................... 244 RRNCF ............................................................................. 245 S SCI. See USART SCK .................................................................................. 125 SDI ................................................................................... 125 SDO ................................................................................. 125 Serial Clock, SCK ............................................................. 125 Serial Communication Interface. See USART Serial Data In, SDI ........................................................... 125 Serial Data Out, SDO ....................................................... 125 Serial Peripheral Interface. See SPI SETF ................................................................................ 245 Slave Select Synchronization ........................................... 131 Slave Select, SS .............................................................. 125 SLEEP ...............................................................195, 205, 246 Software Simulator (MPLAB SIM) .................................... 254 Special Event Trigger. See Compare Special Features of the CPU ............................................ 195 Configuration Registers ................................... 196–201 Special Function Registers ................................................ 42 Map ............................................................................ 45 SPI Master Mode ............................................................ 130 Serial Clock .............................................................. 125 Serial Data In ........................................................... 125 Serial Data Out ........................................................ 125 Slave Select ............................................................. 125 SPI Clock ................................................................. 130 SPI Mode ................................................................. 125 SPI Master/Slave Connection .......................................... 129 SPI Module Associated Registers ............................................... 133 Bus Mode Compatibility ........................................... 133 Effects of a RESET .................................................. 133 Master/Slave Connection ......................................... 129 Slave Mode .............................................................. 131 Slave Select Synchronization .................................. 131 Slave Synch Timing ................................................. 131 SLEEP Operation ..................................................... 133 SS .................................................................................... 125 SSP I 2C Mode. See I2C SPI Mode ................................................................. 125 SPI Mode. See SPI SSPBUF Register .................................................... 130 SSPSR Register ...................................................... 130 TMR2 Output for Clock Shift ............................ 111, 112 SSPOV Status Flag .......................................................... 155 SSPSTAT Register R/W Bit ............................................................. 138, 139 Status Bits Significance and the Initialization Condition for RCON Register ............................................. 27 SUBFWB .......................................................................... 246 SUBLW ............................................................................ 247 SUBWF ............................................................................ 247 SUBWFB .......................................................................... 248 SWAPF ............................................................................ 248 T TABLAT Register ............................................................... 58 Table Pointer Operations (table) ........................................ 58 TBLPTR Register ............................................................... 58 TBLRD ............................................................................. 249 TBLWT ............................................................................. 250 Time-out Sequence ........................................................... 26 Time-out in Various Situations ................................... 27 Timer0 .............................................................................. 103 16-bit Mode Timer Reads and Writes ...................... 105 Associated Registers ............................................... 105 Clock Source Edge Select (T0SE Bit) ..................... 105 Clock Source Select (T0CS Bit) ............................... 105 Operation ................................................................. 105 Overflow Interrupt .................................................... 105 Prescaler. See Prescaler, Timer0 Timer1 .............................................................................. 107 16-bit Read/Write Mode ........................................... 109 Associated Registers ............................................... 110 Operation ................................................................. 108 Oscillator ...........................................................107, 109 Overflow Interrupt .............................................107, 109 Special Event Trigger (CCP) ............................109, 120 TMR1H Register ...................................................... 107 TMR1L Register ....................................................... 107 Timer2 .............................................................................. 111 Associated Registers ............................................... 112 Operation ................................................................. 111 Postscaler. See Postscaler, Timer2 PR2 Register ....................................................111, 122 Prescaler. See Prescaler, Timer2 SSP Clock Shift ................................................111, 112 TMR2 Register ......................................................... 111 TMR2 to PR2 Match Interrupt ...................111, 112, 122 Timer3 .............................................................................. 113 Associated Registers ............................................... 115 Operation ................................................................. 114 Oscillator ...........................................................113, 115 Overflow Interrupt .............................................113, 115 Special Event Trigger (CCP) ................................... 115 TMR3H Register ...................................................... 113 TMR3L Register ....................................................... 113 Timing Diagrams Bus Collision Transmit and Acknowledge ..................... 159 A/D Conversion ........................................................ 287 Acknowledge Sequence .......................................... 158 Baud Rate Generator with Clock Arbitration ............ 152 BRG Reset Due to SDA Arbitration During START Condition ............................................. 161 Brown-out Reset (BOR) ........................................... 274 Bus Collision Start Condition (SDA Only) .............................. 160 Bus Collision During a Repeated START Condition (Case 1) .............................. 162 Bus Collision During a Repeated START Condition (Case 2) .............................. 162 Bus Collision During a START Condition (SCL = 0) ......................................................... 161 Bus Collision During a STOP Condition (Case 1) ........................................................... 163 Bus Collision During a STOP Condition (Case 2) ........................................................... 163 Capture/Compare/PWM (CCP1 and CCP2) ............ 276 CLKO and I/O .......................................................... 272 Clock Synchronization ............................................. 145PIC18FXX2 DS39564C-page 324 © 2006 Microchip Technology Inc. Example SPI Master Mode (CKE = 0) ..................... 278 Example SPI Master Mode (CKE = 1) ..................... 279 Example SPI Slave Mode (CKE = 0) ....................... 280 Example SPI Slave Mode (CKE = 1) ....................... 281 External Clock (All Modes except PLL) .................... 271 First START Bit Timing ............................................ 153 I 2C Bus Data ............................................................ 282 I 2C Bus START/STOP Bits ...................................... 282 I 2C Master Mode (Reception, 7-bit Address) ........... 157 I 2C Master Mode (Transmission, 7 or 10-bit Address) ......................................... 156 I 2C Slave Mode Timing (10-bit Reception, SEN = 0) .......................................................... 142 I 2C Slave Mode Timing (10-bit Transmission) .........143 I 2C Slave Mode Timing (7-bit Reception, SEN = 0) .......................................................... 140 I 2C Slave Mode Timing (7-bit Reception, SEN = 1) .................................................. 146, 147 I 2C Slave Mode Timing (7-bit Transmission) ........... 141 Low Voltage Detect .................................................. 192 Master SSP I2C Bus Data ........................................ 284 Master SSP I2C Bus START/STOP Bits .................. 284 Parallel Slave Port (PIC18F4X2) ..............................277 Parallel Slave Port (Read) ........................................ 101 Parallel Slave Port (Write) ........................................ 100 PWM Output ............................................................. 122 Repeat START Condition ......................................... 154 RESET, Watchdog Timer (WDT), Oscillator Start-up Timer (OST) and Power-up Timer (PWRT) ................................. 273 Slave Synchronization .............................................. 131 Slaver Mode General Call Address Sequence (7 or 10-bit Address Mode) ..............................148 Slow Rise Time (MCLR Tied to VDD) ......................... 33 SPI Mode (Master Mode) ......................................... 130 SPI Mode (Slave Mode with CKE = 0) ..................... 132 SPI Mode (Slave Mode with CKE = 1) ..................... 132 Stop Condition Receive or Transmit Mode .............. 158 Time-out Sequence on POR w/PLL Enabled (MCLR Tied to VDD) ........................................... 33 Time-out Sequence on Power-up (MCLR Not Tied to VDD) Case 1 ................................................................ 32 Case 2 ................................................................ 32 Time-out Sequence on Power-up (MCLR Tied to VDD) ........................................... 32 Timer0 and Timer1 External Clock ........................... 275 Timing for Transition Between Timer1 and OSC1 (HS with PLL) .......................................... 23 Transition Between Timer1 and OSC1 (HS, XT, LP) ....................................................... 22 Transition Between Timer1 and OSC1 (RC, EC) ............................................................ 23 Transition from OSC1 to Timer1 Oscillator ................ 22 USART Asynchronous Master Transmission ........... 173 USART Asynchronous Master Transmission (Back to Back) .................................................. 173 USART Asynchronous Reception ............................175 USART Synchronous Receive (Master/Slave) .........286 USART Synchronous Reception (Master Mode, SREN) ...................................... 178 USART Synchronous Transmission ......................... 177 USART Synchronous Transmission (Master/Slave) .................................................. 286 USART Synchronous Transmission (Through TXEN) .............................................. 177 Wake-up from SLEEP via Interrupt .......................... 206 Timing Diagrams Requirements Master SSP I2C Bus START/STOP Bits .................. 284 Timing Requirements A/D Conversion ........................................................ 288 Capture/Compare/PWM (CCP1 and CCP2) ............ 276 CLKO and I/O .......................................................... 273 Example SPI Mode (Master Mode, CKE = 0) .......... 278 Example SPI Mode (Master Mode, CKE = 1) .......... 279 Example SPI Mode (Slave Mode, CKE = 0) ............ 280 Example SPI Slave Mode (CKE = 1) ....................... 281 External Clock .......................................................... 271 I 2C Bus Data (Slave Mode) ..................................... 283 Master SSP I2C Bus Data ........................................ 285 Parallel Slave Port (PIC18F4X2) ............................. 277 RESET, Watchdog Timer, Oscillator Start-up Timer, Power-up Timer and Brown-out Reset Requirements ....................... 274 Timer0 and Timer1 External Clock .......................... 275 USART Synchronous Receive ................................. 286 USART Synchronous Transmission ........................ 286 Timing Specifications PLL Clock ................................................................ 272 TRISE Register PSPMODE Bit .....................................................95, 100 TSTFSZ ........................................................................... 251 Two-Word Instructions Example Cases .......................................................... 41 TXSTA Register BRGH Bit ................................................................. 168 U Universal Synchronous Asynchronous Receiver Transmitter. See USART USART ............................................................................. 165 Asynchronous Mode ................................................ 172 Associated Registers, Receive ........................ 175 Associated Registers, Transmit ....................... 173 Receiver .......................................................... 174 Transmitter ....................................................... 172 Baud Rate Generator (BRG) ................................... 168 Associated Registers ....................................... 168 Baud Rate Error, Calculating ........................... 168 Baud Rate Formula .......................................... 168 Baud Rates for Asynchronous Mode (BRGH = 0) .............................................. 170 Baud Rates for Asynchronous Mode (BRGH = 1) .............................................. 171 Baud Rates for Synchronous Mode ................. 169 High Baud Rate Select (BRGH Bit) ................. 168 Sampling .......................................................... 168 Serial Port Enable (SPEN Bit) ................................. 165 Synchronous Master Mode ...................................... 176 Associated Registers, Reception ..................... 178 Associated Registers, Transmit ....................... 176 Reception ........................................................ 178 Transmission ................................................... 176 Synchronous Slave Mode ........................................ 179 Associated Registers, Receive ........................ 180 Associated Registers, Transmit ....................... 179 Reception ........................................................ 180 Transmission ................................................... 179© 2006 Microchip Technology Inc. DS39564C-page 325 PIC18FXX2 W Wake-up from SLEEP .............................................. 195, 205 Using Interrupts ........................................................ 205 Watchdog Timer (WDT) ........................................... 195, 203 Associated Registers ............................................... 204 Control Register ....................................................... 203 Postscaler ........................................................ 203, 204 Programming Considerations .................................. 203 RC Oscillator ............................................................ 203 Time-out Period ....................................................... 203 WCOL .............................................................................. 153 WCOL Status Flag ............................................153, 155, 158 WWW, On-Line Support ....................................................... 5 X XORLW ............................................................................ 251 XORWF ........................................................................... 252PIC18FXX2 DS39564C-page 326 © 2006 Microchip Technology Inc. NOTES:© 2006 Microchip Technology Inc. DS39564C-page 327 PIC18FXX2 THE MICROCHIP WEB SITE Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: • Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s guides and hardware support documents, latest software releases and archived software • General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing • Business of Microchip – Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives CUSTOMER CHANGE NOTIFICATION SERVICE Microchip’s customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com, click on Customer Change Notification and follow the registration instructions. CUSTOMER SUPPORT Users of Microchip products can receive assistance through several channels: • Distributor or Representative • Local Sales Office • Field Application Engineer (FAE) • Technical Support • Development Systems Information Line Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://support.microchip.comPIC18FXX2 DS39564C-page 328 Advance Information © 2006 Microchip Technology Inc. READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ Application (optional): Would you like a reply? Y N Device: Literature Number: Questions: FAX: (______) _________ - _________ PIC18FXX2 DS39564C 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document?© 2006 Microchip Technology Inc. DS39564C-page 329 PIC18FXX2 PIC18FXX2 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. − X /XX XXX Temperature Package Pattern Range Device Device PIC18FXX2(1), PIC18FXX2T(2); VDD range 4.2V to 5.5V PIC18LFXX2(1), PIC18LFXX2T(2); VDD range 2.5V to 5.5V Temperature Range I = -40°C to +85°C (Industrial) E = -40°C to +125°C (Extended) Package PT = TQFP (Thin Quad Flatpack) SO = SOIC SP = Skinny Plastic DIP P = PDIP L = PLCC Pattern QTP, SQTP, Code or Special Requirements (blank otherwise) Examples: a) PIC18LF452 - I/P 301 = Industrial temp., PDIP package, Extended VDD limits, QTP pattern #301. b) PIC18LF242 - I/SO = Industrial temp., SOIC package, Extended VDD limits. c) PIC18F442 - E/P = Extended temp., PDIP package, normal VDD limits. Note 1: F = Standard Voltage range LF = Wide Voltage Range 2: T = in tape and reel - SOIC, PLCC, and TQFP packages only.DS39564C-page 330 © 2006 Microchip Technology Inc. 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Discrete detection outputs  Signal Processing:  Self-calibration  Auto drift compensation  Noise filtering  Adjacent Key Suppression® (AKS®) – up to three groups possible  Power:  1.8 V – 5.5 V  Package:  14-pin SOIC RoHS compliant IC  20-pin VQFN RoHS compliant IC Atmel AT42QT1070 Seven-channel QTouch® Touch Sensor IC DATASHEETAT42QT1070 [DATASHEET] 2 9596C–AT42–05/2013 1. Pinouts and Schematics 1.1 Pinout Configuration – Comms Mode (14-pin SOIC) 1.2 Pinout Configuration – Standalone Mode (14-pin SOIC) VDD MODE (Vss) RESET SDA CHANGE KEY2 KEY1 KEY0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 QT1070 SCL KEY6 KEY3 VSS KEY5 KEY4 VDD MODE (Vdd) RESET OUT0 OUT4 KEY2 KEY1 KEY0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 QT1070 OUT3 OUT2 KEY3 VSS OUT1 KEY4AT42QT1070 [DATASHEET] 3 9596C–AT42–05/2013 1.3 Pinout Configuration – Comms Mode (20-pin VQFN) 1.4 Pinout Configuration – Standalone Mode (20-pin VQFN) NCNC VSS VDDNC KEY4 KEY3 KEY2 KEY1 KEY0 MODE (Vss) SDA 1 2 3 4 5 11 12 13 14 15 20 19 18 17 16 6 7 8 9 10 QT1070 RESET CHANGE SCL NC NC NC KEY5 KEY6 NC NC VSS VDD NC KEY4 KEY3 KEY2 KEY1 KEY0 MODE (Vdd) OUT0 1 2 3 4 5 11 12 13 14 15 20 19 18 17 16 6 7 8 9 10 QT1070 RESET OUT4 OUT3 NC NC NC OUT1 OUT2AT42QT1070 [DATASHEET] 4 9596C–AT42–05/2013 1.5 Pin Descriptions I Input only O Output only, push-pull OD Open drain output P Ground or power Table 1-1. Pin Listings (14-pin SOIC) Pin Name (Comms Mode) Name (Standalone Mode) Type Description If Unused, Connect To... 1 VDD VDD P Power – 2 MODE MODE I Mode selection pin Comms Mode – connect to Vss Standalone Mode – connect to Vdd – 3 SDA OUT0 OD Comms Mode – I2 C data line Standalone Mode – open drain output for guard channel Open 4 RESET RESET I RESET – has internal pull-up 60 k resistor Open 5 CHANGE OUT4 OD CHANGE line for controlling the communications flow Comms Mode – connect to CHANGE line Standalone Mode – connect to output Open 6 SCL OUT3 OD Comms Mode – connect to I 2 C clock Standalone Mode – connect to output Open 7 KEY6 OUT2 O/OD Comms Mode – connect to Key 6 Standalone Mode – connect to output Open 8 KEY5 OUT1 O/OD Comms Mode – connect to Key 5 Standalone Mode – connect to output Open 9 KEY4 KEY4 O Key 4 Open 10 KEY3 KEY3 O Key 3 Open 11 KEY2 KEY2 O Key 2 Open 12 KEY1 KEY1 O Key 1 Open 13 KEY0 KEY0 O Key 0 Open 14 VSS VSS P Ground –AT42QT1070 [DATASHEET] 5 9596C–AT42–05/2013 I Input only O Output only, push-pull OD Open drain output P Ground or power Table 1-2. Pin Listings (20-pin VQFN) Pin Name (Comms Mode) Name (Standalone Mode) Type Description If Unused, Connect To... 1 KEY4 KEY4 O Key 4 Open 2 KEY3 KEY3 O Key 3 Open 3 KEY2 KEY2 O Key 2 Open 4 KEY1 KEY1 O Key 1 Open 5 KEY0 KEY0 O Key 0 Open 6 NC NC – Not connected – 7 NC NC – Not connected – 8 VSS VSS P Ground – 9 VDD VDD P Power – 10 NC NC – Not connected – 11 MODE MODE I Mode selection pin Comms Mode – connect to Vss Standalone Mode – connect to Vdd – 12 SDA OUT0 OD Comms Mode – I2 C data line Standalone Mode – open drain output for guard channel Open 13 RESET RESET I RESET – has internal pull-up 60 k resistor Open 14 CHANGE OUT4 OD CHANGE line for controlling the communications flow Comms Mode – connect to CHANGE line Standalone Mode – connects to output Open 15 SCL OUT3 OD Comms Mode – connect to I 2 C clock Standalone Mode – connect to output Open 16 KEY6 OUT2 O/OD Comms Mode – connect to Key 6 Standalone Mode – connect to output Open 17 KEY5 OUT1 O/OD Comms Mode – connect to Key 5 Standalone Mode – connect to output Open 18 NC NC – Not connected – 19 NC NC – Not connected – 20 NC NC – Not connected –AT42QT1070 [DATASHEET] 6 9596C–AT42–05/2013 1.6 Schematics Figure 1-1. Typical Circuit – Comms (14-pin SOIC) Figure 1-2. Typical Circuit – Standalone (14-pin SOIC) Rs6 C1 K4 RSCL Rs5 Rs4 Rs3 Rs2 Rs1 K3 K2 K1 1 QT1070 MODE (Vss) 2 SDA 3 RESET 4 CHANGE 5 SCL 6 KEY6 7 KEY5 8 KEY4 9 KEY3 10 KEY2 11 KEY1 12 KEY0 13 14 Vss Rs0 K0 Vss Vdd CHANGE SDA RESET K5 K6 Vdd SCL Vdd Vss RSDA Vdd RCHG RRST ROUT2 C1 K4 ROUT3 ROUT1 Rs4 Rs3 Rs2 Rs1 K3 K2 K1 1 OUT0 3 RESET 4 OUT4 5 OUT3 6 OUT2 7 OUT1 8 KEY4 9 KEY3 10 KEY2 11 KEY1 12 KEY0 13 Vss Rs0 K0 Vss ROUT4 Vdd RESET COUT1 COUT2 COUT3 Vss COUT4 COUT0 14 Vss QT1070 Vdd Vss OUTPUTS OUTPUTS ROUT0 MODE (Vdd) 2 COUT1, 2 3 and are optional COUT0 4 and are optional R1 VddAT42QT1070 [DATASHEET] 7 9596C–AT42–05/2013 Figure 1-3. Typical Circuit – Comms (20-pin VQFN) Figure 1-4. Typical Circuit – Standalone (20-pin VQFN) For component values in Figure 1-1, 1-2, 1-3, and 1-4, check the following sections: Section 3.1 on page 12: Series resistors (Rs0 – Rs6 for comms mode and Rs0 – Rs4 for standalone mode) Section 3.2 on page 12: LED traces Section 3.4 on page 12: Power Supply (voltage levels) Section 4.4 on page 14: SDA, SCL pull-up resistors Rs6 C1 K4 Rs5 Rs4 Rs3 Rs2 Rs1 K3 K2 K1 9 QT1070 SCL 15 SDA 12 RESET 13 CHANGE 14 KEY6 16 KEY5 17 KEY4 1 KEY3 2 KEY2 3 KEY1 4 KEY0 5 8 Vss Rs0 K0 Vss Vdd K5 K6 RSCL Vdd Vdd Vss 11 MODE (Vss) N/C N/C 18 N/C 19 N/C 20 N/C 7 N/C 6 10 CHANGE SDA RESET RSDA Vdd RCHG RRST RsOUT2 K4 RsOUT3 RLOUT1 Rs4 Rs3 Rs2 Rs1 K3 K2 K1 OUT0 12 RESET 13 OUT4 14 OUT3 15 OUT2 16 OUT1 17 KEY4 1 KEY3 2 KEY2 3 KEY1 KEY0 5 Vss Rs0 K0 ROUT4 RESET COUT1 COUT2 COUT3 Vss COUT4 COUT0 8 QT1070 Vss OUTPUTS OUTPUTS N/C N/C 18 N/C 19 N/C 20 N/C 7 N/C 6 10 4 ROUT0 Vss C1 9 Vss Vdd MODE (Vdd) Vdd 11 COUT1, 2 3 and are optional COUT0 4 and are optional R1 VddAT42QT1070 [DATASHEET] 8 9596C–AT42–05/2013 2. Overview 2.1 Introduction The AT42QT1070 (QT1070) is a digital burst mode charge-transfer (QT™) capacitive sensor driver. The device can sense from one to seven keys, dependent on mode. The QT1070 includes all signal processing functions necessary to provide stable sensing under a wide variety of changing conditions, and the outputs are fully debounced. Only a few external parts are required for operation and no external Cs capacitors are required. The QT1070 modulates its bursts in a spread-spectrum fashion in order to heavily suppress the effects of external noise, and to suppress RF emissions. The QT1070 uses a dual-pulse method of acquisition. This provides greater noise immunity and eliminates the need for external sampling capacitors, allowing touch sensing using a single pin. 2.2 Modes 2.2.1 Comms Mode The QT1070 can operate in comms mode where a host can communicate with the device via an I2 C bus. This allows the user to configure settings for Threshold, Adjacent Key Suppression (AKS), Detect Integrator, Low Power (LP) Mode, Guard Channel and Max Time On for keys. 2.2.2 Standalone Mode The QT1070 can operate in a standalone mode where an I2 C interface is not required. To enter standalone mode, connect the Mode pin to Vdd before powering up the QT1070. In standalone mode, the start-up values are hard coded in firmware and cannot be changed. The default start-up values are used. This means that key detection is reported via their respective IOs. The Guard channel feature is automatically implemented on key 0 in standalone mode. This means that this channel gets priority over all other keys going into touch. 2.3 Keys Dependent on mode, the QT1070 can have a minimum of one key and a maximum of seven keys. These can be constructed in different shapes and sizes. See “Features” on page 1 for the recommended dimensions.  Comms mode – 1 to 7 keys (or 1 to 6 keys plus Guard Channel)  Standalone mode – 1 to 4 keys plus a Guard Channel Unused keys should be disabled by setting the averaging factor to zero (see Section 5.9 on page 18). The status register can be read to determine the touch status of the corresponding key. It is recommended using the open-drain CHANGE line to detect when a change of status has occurred. 2.4 Input/Output (IO) Lines There are no IO lines in comms mode. In Standalone mode pins OUT0 – OUT4 can be used as open drain outputs for driving LEDs. 2.5 Acquisition/Low Power Mode (LP) There are 255 different acquisition times possible. These are controlled via the LP mode byte (see Section 5.11 on page 19) which can be written to via I2 C communication. LP mode controls the intervals between acquisition measurements. Longer intervals consume lower power but have an increased response time. During calibration, touch and during the detect integrator (DI) period, the LP mode is temporarily set to LP mode 1 for a faster response.AT42QT1070 [DATASHEET] 9 9596C–AT42–05/2013 The QT1070 operation is based on a fixed cycle time of approximately 8 ms. The LP mode setting indicates how many of these periods exist per measurement cycle. For example, If LP mode = 1, there is an acquisition every cycle (8 ms). If LP mode = 3, there is an acquisition every 3 cycles (24 ms). If a high Averaging Factor (see Section 5.9 on page 18) setting is selected then the acquisition time may exceed 8 ms. LP settings above mode 32 (256 ms) result in slower thermal drift compensation and should be avoided in applications where fast thermal transients occur. 2.6 Adjacent Key Suppression (AKS) Technology The device includes the Atmel-patented Adjacent Key Suppression (AKS) technology, to allow the use of tightly spaced keys on a keypad with no loss of selectability by the user. There can be up to three AKS groups, implemented so that only one key in the group may be reported as being touched at any one time. Once a key in a particular AKS group is in detect no other key in that group can go into detect. Only when the key in detect goes out of detection can another key go into detect state. The keys which are members of the AKS groups can be set (see Section 5.9 on page 18). Keys outside the group may be in detect simultaneously. 2.7 CHANGE Line (Comms Mode Only) The CHANGE line is active low and signals when there is a change of state in the Detection or Input key status bytes. It is cleared (allowed to float high) when the host reads the status bytes. If the status bytes change back to their original state before the host has read the status bytes (for example, a touch followed by a release), the CHANGE line will be held low. In this case, a read to any memory location will clear the CHANGE line. The CHANGE line is open-drain and should be connected via a 47 k resistor to Vdd. It is necessary for minimum power operation as it ensures that the QT1070 can sleep for as long as possible. Communications wake up the QT1070 from sleep causing a higher power consumption if the part is randomly polled. Note: The CHANGE line is pulled low 100 ms after power-up or reset. 2.8 Types of Reset 2.8.1 External Reset An external reset logic line can be used if desired, fed into the RESET pin. However, under most conditions it is acceptable to tie RESET to Vdd. 2.8.2 Soft Reset The host can cause a device reset by writing a nonzero value to the RESET byte. This soft reset triggers the internal watchdog timer on a 125 ms interval. After 125 ms the device resets and wakes again. The device NACKs any attempts to communicate with it during the first 30 ms of its initialization period. 2.9 Calibration Writing a non-zero value to the calibration byte can force a recalibration at any time. This can be useful to clear out a stuck key condition after a prolonged period of uninterrupted detection. Note: A calibrate command clears all key status bits and the overflow bit (until it is checked on the next cycle).AT42QT1070 [DATASHEET] 10 9596C–AT42–05/2013 2.10 Guard Channel A guard channel to help prevent false detection is available in both modes. This is fixed on key 0 for standalone mode and programmable for comms mode. Guard channel keys should be more sensitive than the other keys (physically bigger). Because the guard channel key is physically bigger it becomes more susceptible to noise so it has a higher Averaging Factor (see Section 5.9 on page 18) and a lower Threshold (see Section 5.8 on page 18) than the other keys. In standalone mode it has an Averaging Factor of 16 and a Threshold of 10 counts. A channel set as the guard channel (there can only be one) is prioritised when the filtering of keys going into detect is taking place. So if a normal key is filtering into touch (touch present but DI has not been reached) and the key set as the guard key begins filtering in, then the normal key’s filter is reset and the guard key filters in first. The guard channel is connected to a sensor pad which detects the presence of touch and overrides any output from the other keys. Figure 2-1. Guard Channel Example 2.11 Signal Processing 2.11.1 Detect Threshold The device detects a touch when the signal has crossed a threshold level and remained there for a specified number of counts (see Section 5.10 on page 19). This can be altered on a key-by-key basis using the key threshold I2C commands. In standalone mode the detect threshold is set to a fixed value of 10 counts of change with respect to the internal reference level for the guard channel and 20 counts for the other four keys. The reference level has the ability to adjust itself slowly in accordance with the drift compensation mechanism. The drift mechanism will drift toward touch at a rate of 160 ms × 18 = 2.88 seconds and away from touch at a rate of 160 ms × 6 = 0.96 seconds. The 160 ms is based on 20 × 8 ms cycles. If the cycle time exceeds 8 ms then the overall times will be extended to match. 2.11.2 Detect Integrator The device features a fast detection integrator counter (DI filter), which acts to filter out noise at the small expense of a slower response time. The DI filter requires a programmable number of consecutive samples confirmed in detection before the key is declared to be touched. The minimum number for the DI filter is 2. Settings of 0 and 1 for the DI also default to 2. The DI is also implemented when a touch is removed. This uses the Fast Out DI option. When bit 5 of Address 53 is set the a key filters out with an integrator of 4. Guard channelAT42QT1070 [DATASHEET] 11 9596C–AT42–05/2013 2.11.3 Cx Limitations The recommended range for key capacitance Cx is 1 pF – 30 pF. Larger values of Cx will give reduced sensitivity. 2.11.4 Max On Duration If an object or material obstructs the sense pad the signal may rise enough to create a detection, preventing further operation. To prevent this, the sensor includes a timer which monitors detections. If a detection exceeds the timer setting the sensor performs a key recalibration. This is known as the Max On duration feature and is set to approximately 30 s in standalone mode. In comms mode this feature can be changed by setting a value in the range 1 – 255 (160 ms – 40,800 ms) in steps of 160 ms. A setting of 0 disables the Max On Duration recalibration feature. Note: If bit 4 of address 53 is clear then a recalibration of all keys occurs on Max On Duration, otherwise individual key recalibration occurs. 2.11.5 Positive Recalibration If a keys signal jumps in the negative direction (with respect to its reference) by more than the Positive Recalibration setting (4 counts), then a recalibration of that key takes place. 2.11.6 Drift Hold Time Drift Hold Time (DHT) is used to restrict drift on all keys while one or more keys are activated. DHT restricts the drifting on all keys until approximately four seconds after all touches have been removed. This feature is particularly useful in cases of high-density keypads where touching a key or hovering a finger over the keypad would cause untouched keys to drift, and therefore create a sensitivity shift, and ultimately inhibit touch detection. 2.11.7 Hysteresis Hysteresis is fixed at 12.5% of the Detect Threshold. When a key enters a detect state once the DI count has been reached, the NTHR value is changed by a small amount (12.5% of NTHR) in the direction away from touch. This is done to affect hysteresis and so makes it less likely a key will dither in and out of detect. NTHR is restored once the key drops out of detect.+AT42QT1070 [DATASHEET] 12 9596C–AT42–05/2013 3. Wiring and Parts 3.1 Rs Resistors Series resistors Rs (Rs0 – Rs6 for comms mode and Rs0 – Rs4 for standalone mode) are in line with the electrode connections and should be used to limit electrostatic discharge (ESD) currents and to suppress radio frequency interference (RFI). Series resistors are recommended for noise reduction. They should be approximately 4.7 k to 20 k each. 3.2 LED Traces and Other Switching Signals Digital switching signals near the sense lines induce transients into the acquired signals, deteriorating the signal-tonoise (SNR) performance of the device. Such signals should be routed away from the sensing traces and electrodes, or the design should be such that these lines are not switched during the course of signal acquisition (bursts). LED terminals which are multiplexed or switched into a floating state, and which are within, or physically very near, a key (even if on another nearby PCB) should be bypassed to either Vss or Vdd with at least a 10 nF capacitor. This is to suppress capacitive coupling effects which can induce false signal shifts. The bypass capacitor does not need to be next to the LED, in fact it can be quite distant. The bypass capacitor is noncritical and can be of any type. LED terminals which are constantly connected to Vss or Vdd do not need further bypassing. 3.3 PCB Cleanliness Modern no-clean flux is generally compatible with capacitive sensing circuits. If a PCB is reworked in any way, clean it thoroughly to remove all traces of the flux residue around the capacitive sensor components. Dry it thoroughly before any further testing is conducted. 3.4 Power Supply See Section 6.2 on page 22 for the power supply range. If the power supply fluctuates slowly with temperature, the device tracks and compensates for these changes automatically with only minor changes in sensitivity. If the supply voltage drifts or shifts quickly, the drift compensation mechanism is not able to keep up, causing sensitivity anomalies or false detections. The usual power supply considerations with QT parts apply to the device. The power should be clean and come from a separate regulator if possible. However, this device is designed to minimize the effects of unstable power, and except in extreme conditions should not require a separate Low Dropout (LDO) regulator. It is assumed that a larger bypass capacitor (such as1 µF) is somewhere else in the power circuit; for example, near the regulator. CAUTION: If a PCB is reworked in any way, it is highly likely that the behavior of the no-clean flux will change. This can mean that the flux changes from an inert material to one that can absorb moisture and dramatically affect capacitive measurements due to additional leakage currents. If so, the circuit can become erratic and exhibit poor environmental stability. CAUTION: A regulator IC shared with other logic can result in erratic operation and is not advised. A single ceramic 0.1 µF bypass capacitor, with short traces, should be placed very close to the power pins of the IC. Failure to do so can result in device oscillation, high current consumption and erratic operation.AT42QT1070 [DATASHEET] 13 9596C–AT42–05/2013 4. I2 C Communications (Comms Mode Only) 4.1 I2 C Protocol 4.1.1 Protocol The I2C protocol is based around access to an address table (see Table 5-1 on page 15) and supports multibyte reads and writes. The maximum clock rate is 400 kHz. See Section A. on page 29 for an overview of I2 C bus operation. 4.1.2 Signals The I2 C interface requires two signals to operate:  SDA - Serial Data  SCL - Serial Clock A third line, CHANGE, is used to signal when the device has seen a change in the status byte: CHANGE: Open-drain, active low when any capacitive key has changed state since the last I2 C read. After reading the two status bytes, this pin floats (high) again if it is pulled up with an external resistor. If the status bytes change back to their original state before the host has read the status bytes (for example, a touch followed by a release), the CHANGE line is held low. In this case, a read to any memory location clears the CHANGE line. 4.2 I2 C Address There is one preset I2 C address of 0x1B. This is not changeable. 4.3 Data Read/Write 4.3.1 Writing Data to the Device The sequence of events required to write data to the device is shown next. 1. The host initiates the transfer by sending the START condition 2. The host follows this by sending the slave address of the device together with the WRITE bit. 3. The device sends an ACK. Table 4-1. Description of Write Data Bits Key Description S START condition SLA+W Slave address plus write bit A Acknowledge bit MemAddress Target memory address within device Data Data to be written P Stop condition S SLA+W A A MemAddress Data A P Host to Device Device Tx to HostAT42QT1070 [DATASHEET] 14 9596C–AT42–05/2013 4. The host then sends the memory address within the device it wishes to write to. 5. The device sends an ACK if the write address is in the range 0x00 – 0x7F, otherwise it sends a NACK. 6. The host transmits one or more data bytes; each is acknowledged by the device (unless trying to write to an invalid address). 7. If the host sends more than one data byte, they are written to consecutive memory addresses. 8. The device automatically increments the target memory address after writing each data byte. 9. After writing the last data byte, the host should send the STOP condition. Note: the host should not try to write to addresses outside the range 0x20 to 0x39 because this is the limit of the device internal memory address. 4.3.2 Reading Data From the Device The sequence of events required to read data from the device is shown next. 1. The host initiates the transfer by sending the START condition 2. The host follows this by sending the slave address of the device together with the WRITE bit. 3. The device sends an ACK. 4. The host then sends the memory address within the device it wishes to read from. 5. The device sends an ACK if the address to be read from is less than 0x80 otherwise it sends a NACK). 6. The host must then send a STOP and a START condition followed by the slave address again but this time accompanied by the READ bit. Note: Alternatively, instead of step 6 a repeated START can be sent so the host does not need to relinquish control of the bus. 7. The device returns an ACK, followed by a data byte. 8. The host must return either an ACK or NACK. 1. If the host returns an ACK, the device subsequently transmits the data byte from the next address. Each time a data byte is transmitted, the device automatically increments the internal address. The device continues to return data bytes until the host responds with a NACK. 2. If the host returns a NACK, it should then terminate the transfer by issuing the STOP condition. 9. The device resets the internal address to the location indicated by the memory address sent to it previously. Therefore, there is no need to send the memory address again when reading from the same location. Note: Reading the 16-bit reference and signal values is not an automatic operation; reading the first byte of a 16- bit value does not lock the other byte. As a result glitches in the reported value may be seen as values increase from 255 to 256, or decrease from 256 to 255. 4.4 SDA, SCL The I2 C bus transmits data and clock with SDA and SCL respectively. They are open-drain; that is I2 C master and slave devices can only drive these lines low or leave them open. The termination resistors pull the line up to Vdd if no I 2 C device is pulling it down. The termination resistors commonly range from 1 k to 10 k and should be chosen so that the rise times on SDA and SCL meet the I2 C specifications (1 µs maximum). Standalone mode: if I2 C communications are not required, then standalone mode can be enabled by connecting the MODE pin to Vdd. See Section 2.4 on page 8 for more information. S SLA+W A A MemAddress S SLA+R A A P Host to Device Device Tx to Host P Data 1 Data 2 A Data n AAT42QT1070 [DATASHEET] 15 9596C–AT42–05/2013 5. Setups 5.1 Introduction The device calibrates and processes signals using a number of algorithms specifically designed to provide for high survivability in the face of adverse environmental challenges. User-defined Setups are employed to alter these algorithms to suit each application. These Setups are loaded into the device over the I2C serial interfaces. In standalone mode these settings are fixed to predetermined values. Table 5-1. Internal Register Address Allocation Address Use Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 R/W 0 Chip ID Major ID (= 2) Minor ID (= E) R 1 Firmware Version Firmware version number R 2 Detection status CALIBRATE OVERFLOW – – – – – TOUCH R 3 Key status Reserved Key 6 Key 5 Key 4 Key 3 Key 2 Key 1 Key 0 R 4 – 5 Key signal 0 Key signal 0 (MSByte) – Key signal 0 (LSByte) R 6 – 7 Key signal 1 Key signal 1 (MSByte) – Key signal 1 (LSByte) R 8 – 9 Key signal 2 Key signal 2 (MSByte) – Key signal 2 (LSByte) R 10 – 11 Key signal 3 Key signal 3 (MSByte) – Key signal 3 (LSByte) R 12 – 13 Key signal 4 Key signal 4 (MSByte) – Key signal 4 (LSByte) R 14 – 15 Key signal 5 Key signal 5 (MSByte) – Key signal 5 (LSByte) R 16 – 17 Key signal 6 Key signal 6 (MSByte) – Key signal 6 (LSByte) R 18 – 19 Reference data 0 Reference data 0 (MSByte) – Reference data 0 (LSByte) R 20 – 21 Reference data 1 Reference data 1 (MSByte) – Reference data 1 (LSByte) R 22 – 23 Reference data 2 Reference data 2 (MSByte) – Reference data 2 (LSByte) R 24 – 25 Reference data 3 Reference data 3 (MSByte) – Reference data 3 (LSByte) R 26 – 27 Reference data 4 Reference data 4 (MSByte) – Reference data 4 (LSByte) R 28 – 29 Reference data 5 Reference data 5 (MSByte) – Reference data 5 (LSByte) R 30 – 31 Reference data 6 Reference data 6 (MSByte) – Reference data 6 (LSByte) R 32 NTHR key 0 Negative Threshold level for key 0 R/W 33 NTHR key 1 Negative Threshold level for key 1 R/W 34 NTHR key 2 Negative Threshold level for key 2 R/W 35 NTHR key 3 Negative Threshold level for key 3 R/W 36 NTHR key 4 Negative Threshold level for key 4 R/W 37 NTHR key 5 Negative Threshold level for key 5 R/W 38 NTHR key 6 Negative Threshold level for key 6 R/W 39 AVE/AKS key 0 Adjacent key suppression level for key 0 R/W 40 AVE/AKS key 1 Adjacent key suppression level for key 1 R/WAT42QT1070 [DATASHEET] 16 9596C–AT42–05/2013 5.2 Address 0: Chip ID MAJOR ID: Reads back as 2 MINOR ID: Reads back as E 5.3 Address 1: Firmware Version FIRMWARE VERSION: this shows the 8-bit firmware version 1.5 (0x15). 41 AVE/AKS key 2 Adjacent key suppression level for key 2 R/W 42 AVE/AKS key 3 Adjacent key suppression level for key 3 R/W 43 AVE/AKS key 4 Adjacent key suppression level for key 4 R/W 44 AVE/AKS key 5 Adjacent key suppression level for key 5 R/W 45 AVE/AKS key 6 Adjacent key suppression level for key 6 R/W 46 DI key 0 Detection integrator counter for key 0 R/W 47 DI key 1 Detection integrator counter for key 1 R/W 48 DI key 2 Detection integrator counter for key 2 R/W 49 DI key 3 Detection integrator counter for key 3 R/W 50 DI key 4 Detection integrator counter for key 4 R/W 51 DI key 5 Detection integrator counter for key 5 R/W 52 DI key 6 Detection integrator counter for key 6 R/W 53 FO/MO/Guard No FastOutDI/ Max Cal/Guard Channel R/W 54 LP Low Power (LP) Mode R/W 55 Max On Duration Maximum On Duration R/W 56 Calibrate Calibrate R/W 57 RESET RESET R/W Table 5-1. Internal Register Address Allocation (Continued) Address Use Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 R/W Table 5-2. Chip ID Address b7 b6 b5 b4 b3 b2 b1 b0 0 MAJOR ID MINOR ID Table 5-3. Firmware Version Address b7 b6 b5 b4 b3 b2 b1 b0 1 FIRMWARE VERSION AT42QT1070 [DATASHEET] 17 9596C–AT42–05/2013 5.4 Address 2: Detection Status CALIBRATE: This bit is set during a calibration sequence. OVERFLOW: This bit is set if the time to acquire all key signals exceeds 8 ms. TOUCH: This bit is set if any keys are in detect. 5.5 Address 3: Key Status KEY0 – 6: bits 0 to 6 indicate which keys are in detection, if any. Touched keys report as 1, untouched or disabled keys report as 0. 5.6 Address 4 – 17: Key Signal KEY SIGNAL: addresses 4 – 17 allow key signals to be read for each key, starting with key 0. There are two bytes of data for each key. These are the key’s 16-bit key signals which are accessed as two 8-bit bytes, stored MSByte first. These addresses are read-only. Table 5-4. Detection Status Address b7 b6 b5 b4 b3 b2 b1 b0 2 CALIBRATE OVERFLO W – – – – – TOUCH Table 5-5. Key Status Address b7 b6 b5 b4 b3 b2 b1 b0 3 Reserved KEY6 KEY5 KEY4 KEY3 KEY2 KEY1 KEY0 Table 5-6. Key Signal Address b7 b6 b5 b4 b3 b2 b1 b0 4 MSByte OF KEY SIGNAL FOR KEY 0 5 LSByte OF KEY SIGNAL FOR KEY 0 6 – 17 MSByte/LSByte OF KEY SIGNAL FOR KEYS 1 – 6AT42QT1070 [DATASHEET] 18 9596C–AT42–05/2013 5.7 Address 18 – 31: Reference Data REFERENCE DATA: addresses 18 – 31 allow reference data to be read for each key, starting with key 0. There are two bytes of data for each key. These are the key’s 16-bit reference data which is accessed as two 8-bit bytes, stored MSByte first. These addresses are read-only. 5.8 Address 32 – 38: Negative Threshold (NTHR) NTHR Keys 0 – 6: these 8-bit values set the threshold value for each key to register a detection. Default: 20 counts Note: Do not use a setting of 0 as this causes a key to go into detection when its signal is equal to its reference. 5.9 Address 39 – 45: Averaging Factor/Adjacent Key Suppression (AVE/AKS) AVE 0 – 5: The Averaging Factor (AVE) is the number of pulses which are added together and averaged to get the final signal value for that channel. For example, if AVE = 8 then 8 ADC samples are taken and added together. The result is divided by the original number of pulses (8). If sixteen pulses are used then the result is divided by sixteen. This provides a better signal-to-noise ratio but requires longer acquire times. Values for AVE are restricted internally to 1, 2, 4, 8, 16 or 32. Default: 8 (In standalone mode key 0 is 16) AKS 0 – 1: these bits control which keys are included in an AKS group. There can be up to three groups, each containing any number of keys (up to the maximum allowed for the mode). Each key can have a value between 0 and 3, which assigns it to an AKS group of that number. A key may only go into detect when it has the largest signal change of any key in its group. A value of 0 means the key is not in any AKS group. Default: 0x01 Table 5-7. Reference Data Address b7 b6 b5 b4 b3 b2 b1 b0 18 MSByte OF REFERENCE DATA FOR KEY 0 19 LSByte OF REFERENCE DATA FOR KEY 0 20 – 31 MSByte/LSByte OF REFERENCE DATA FOR KEYS 1 – 6 Table 5-8. NTHR Address b7 b6 b5 b4 b3 b2 b1 b0 32 – 38 NEGATIVE THRESHOLD FOR KEYS 0 – 6 Table 5-9. AVE/AKS Address b7 b6 b5 b4 b3 b2 b1 b0 39 – 45 AVE5 AVE4 AVE3 AVE2 AVE1 AVE0 AKS1 AKS0AT42QT1070 [DATASHEET] 19 9596C–AT42–05/2013 5.10 Address 46 – 52: Detection Integrator (DI) DETECTION INTEGRATOR: addresses 46 – 52 allow the DI level to be set for each key. This 8-bit value controls the number of consecutive measurements that must be confirmed as having passed the key threshold before that key is registered as being in detect. The minimum value for the DI filter is 2. Settings of 0 and 1 for the DI also default to 2 because a minimum of two consecutive measurements must be confirmed. Default: 4 5.11 Address 53: FastOutDI/Max Cal/Guard Channel FO: Fast Out DI – when bit 5 is set then a key filters out with an integrator of 4. Could have a DI in of 100 but filter out with DI of 4 (global setting for all keys). MAX CAL: if this bit is clear then all keys recalibrate after a Max On Duration timeout, otherwise only the key with the incorrect timing gets recalibrated. GUARD CHANNEL: bits 0 – 3 are used to set a key as the guard channel (which gets priority filtering). Valid values are 0 – 6, with any larger value disabling the guard key feature. 5.12 Address 54: Low Power (LP) Mode Table 5-10. Detection Integrator Address b7 b6 b5 b4 b3 b2 b1 b0 46 – 52 DETECTION INTEGRATOR Table 5-11. Max Cal/Guard Channel Address b7 b6 b5 b4 b3 b2 b1 b0 53 – FO MAX CAL GUARD CHANNEL Table 5-12. LP Mode Address b7 b6 b5 b4 b3 b2 b1 b0 54 LOW POWER MODEAT42QT1070 [DATASHEET] 20 9596C–AT42–05/2013 LP MODE: this 8-bit value determines the number of 8 ms intervals between key measurements. Longer intervals between measurements yield a lower power consumption but at the expense of a slower response to touch. Default: 2 (16 ms between key acquisitions) 5.13 Address 55: Max On Duration MAX ON DURATION: this is a 8-bit value which determines how long any key can be in touch before it recalibrates itself. A value of 0 turns Max On Duration off. Default: 180 (160 ms × 180 = 28.8s) Setting Time 0 8 ms 1 8 ms 2 16 ms 3 24 ms 4 32 ms   254 2.032s 255 2.040s Table 5-13. Max Time On Address b7 b6 b5 b4 b3 b2 b1 b0 55 MAX ON DURATION Setting Time 0 Off 1 160 ms 2 320 ms 3 480 ms 4 640 ms 255 40.8sAT42QT1070 [DATASHEET] 21 9596C–AT42–05/2013 5.14 Address 56: Calibrate Writing any nonzero value into this address triggers the device to start a calibration cycle. The CALIBRATE flag in the detection status register is set when the calibration begins and clears when the calibration has finished. 5.15 Address 57: RESET Writing any nonzero value to this address triggers the device to reset. Table 5-14. Calibrate Address b7 b6 b5 b4 b3 b2 b1 b0 56 Writing a nonzero value forces a calibration Table 5-15. RESET Address b7 b6 b5 b4 b3 b2 b1 b0 57 Writing a nonzero value forces a resetAT42QT1070 [DATASHEET] 22 9596C–AT42–05/2013 6. Specifications 6.1 Absolute Maximum Specifications 6.2 Recommended Operating Conditions 6.3 DC Specifications Vdd –0.5 to +6 V Max continuous pin current, any control or drive pin ±10 mA Short circuit duration to ground, any pin infinite Short circuit duration to Vdd, any pin infinite Voltage forced onto any pin –0.5 V to (Vdd + 0.5) V CAUTION: Stresses beyond those listed under Absolute Maximum Specifications may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum specification conditions for extended periods may affect device reliability. Operating temperature –40o C to +85o C Storage temperature –55o C to +125o C Vdd +1.8 V to 5.5 V Supply ripple+noise ±25 mV Cx load capacitance per key 1 to 30 pF Vdd = 3.3 V, Cs = 10 nF, load = 5 pF, 32 ms default sleep, Ta = recommended range, unless otherwise noted Parameter Description Minimum Typical Maximum Units Notes Vil Low input logic level – – 0.2 × Vdd V Vih High input logic level 0.7 × Vdd – Vdd + 0.5 V Vol Low output voltage – – 0.6 V Voh High output voltage Vdd – 0.7V – – V Iil Input leakage current – – ±1 µAAT42QT1070 [DATASHEET] 23 9596C–AT42–05/2013 6.4 Power Consumption Measurements 6.5 Timing Specifications Cx = 5 pF, Rs = 4.7 k LP Mode Idd (µA) at Vdd = 5 V 3.3 V 1.8 V 0 (8 ms) 1744 906 442 1 (16 ms) 1375 615 305 2 (24 ms) 1263 525 261 4 (32 ms) 1168 486 234 5 (40 ms) 1119 445 221 6 (48 ms) 1089 434 211 Paramete r Description Minimum Typica l Maximum Units Notes TR Response time DI setting × 8 ms – LP mode + (DI setting × 8 ms) ms Under host control FQT Sample frequency 162 180 198 kHz Modulated spread-spectrum (chirp) TD Power-up delay to operate/calibration time – <230 – ms Can be longer if burst is very long. FI2C I 2 C clock rate – – 400 kHz – Fm Burst modulation, percentage ±8 % – RESET pulse width 5 – – µs –AT42QT1070 [DATASHEET] 24 9596C–AT42–05/2013 6.6 Mechanical Dimensions 6.7 AT42QT1070-SSU – 14-pin SOIC 42077B-MCU-10/2013 USER GUIDE Atmel OLED1 Xplained Pro Preface Atmel® OLED1 Xplained Pro is an extension board to the Atmel Xplained Pro evaluation platform. The board enables the user to experiment with user interface applications with buttons, LEDs and a display.Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 2 Table of Contents Preface .......................................................................................... 1 1. Introduction .............................................................................. 3 1.1. Features .............................................................................. 3 1.2. Kit overview ......................................................................... 3 2. Getting started ......................................................................... 4 2.1. 3 Steps to start exploring the Atmel Xplained Pro platform ............. 4 2.2. Connecting OLED1 Xplained Pro to the Xplained Pro MCU board. ................................................................................. 4 2.3. Design documentation and related links ..................................... 4 3. Xplained Pro ............................................................................ 5 3.1. Hardware identification system ................................................. 5 3.2. Standard headers and connectors ............................................ 5 3.2.1. Xplained Pro Standard Extension Header ...................... 5 4. Hardware user guide .............................................................. 7 4.1. Headers and connectors ......................................................... 7 4.1.1. OLED1 Xplained Pro extension header ......................... 7 4.2. Peripherals ........................................................................... 7 4.2.1. LEDs ...................................................................... 7 4.2.2. Push buttons ............................................................ 7 4.2.3. OLED display ........................................................... 8 5. Hardware revision history and known issues .......................... 9 5.1. Identifying product ID and revision ............................................ 9 5.2. Revision 3 ........................................................................... 9 6. Document revision history ..................................................... 10 7. Evaluation board/kit important notice .................................... 11Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 3 1. Introduction 1.1 Features ● UG-2832HSWEG04 monochrome OLED display ● 128 x 32 Pixels ● Controlled by 4-wire SPI interface, up to 100MHz ● Three LEDs ● Three Mechanical push buttons ● Xplained Pro hardware identification system 1.2 Kit overview OLED1 Xplained Pro is a basic extension board for the Xplained Pro platform with three LEDs, three push buttons and an OLED display. The OLED display is controlled via a SPI interface up to 100MHz. OLED1 Xplained Pro connects to any Xplained Pro standard extension header on any Xplained Pro MCU board. Figure 1-1. OLED1 Xplained Pro top overview.Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 4 2. Getting started 2.1 3 Steps to start exploring the Atmel Xplained Pro platform 1. Download and install Atmel Studio. 2. Launch Atmel Studio. 3. Connect OLED1 Xplained Pro to an Xplained Pro MCU board and connect a USB cable to DEBUG USB port on the Xplained Pro MCU board. 2.2 Connecting OLED1 Xplained Pro to the Xplained Pro MCU board. Atmel OLED1 Xplained Pro has been designed to be connected to the Xplained Pro header marked EXT3. However it is compatible with all Xplained Pro EXT headers. Please refer to the pin-out of your Xplained Pro evaluation kit to find out which Xplained Pro EXT headers that can be used. Once the Xplained Pro MCU board is powered the green power LED will be lit and Atmel Studio will auto detect which Xplained Pro MCU- and extension board(s) that is connected. You will be presented with relevant information like datasheets and kit documentation. You also have the option to launch Atmel Software Framework (ASF) example applications. The target device is programmed and debugged by the on-board Embedded Debugger. No external programmer or debugger tool is needed. 2.3 Design documentation and related links The following list contains links to the most relevant documents and software for OLED1 Xplained Pro. 1. Xplained Pro products 1 - Atmel Xplained Pro is a series of small-sized and easy-to-use evaluation kits for 8- and 32-bit Atmel microcontrollers. It consists of a series of low cost MCU boards for evaluation and demonstration of features and capabilities of different MCU families. 2. OLED1 Xplained Pro User Guide 2 - PDF version of this User Guide. 3. OLED1 Xplained Pro Design Documentation 3 - Package containing schematics, BOM, assembly drawings, 3D plots, layer plots etc. 4. Atmel Studio 4 - Free Atmel IDE for development of C/C++ and assembler code for Atmel microcontrollers. 1 http://www.atmel.com/XplainedPro 2 http://www.atmel.com/Images/Atmel-42077-OLED1-Xplained-Pro_User-Guide.pdf 3 http://www.atmel.com/Images/Atmel-42077-OLED1-Xplained-Pro_User-Guide.zip 4 http://www.atmel.com/atmelstudioAtmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 5 3. Xplained Pro Xplained Pro is an evaluation platform that provides the full Atmel microcontroller experience. The platform consists of a series of Microcontroller (MCU) boards and extension boards that are integrated with Atmel Studio, have Atmel Software Framework (ASF) drivers and demo code, support data streaming and more. Xplained Pro MCU boards support a wide range of Xplained Pro extension boards that are connected through a set of standardized headers and connectors. Each extension board has an identification (ID) chip to uniquely identify which boards are mounted on a Xplained Pro MCU board. This information is used to present relevant user guides, application notes, datasheets and example code through Atmel Studio. Available Xplained Pro MCU and extension boards can be purchased in the Atmel Web Store 1 . 3.1 Hardware identification system All Xplained Pro compatible extension boards have an Atmel ATSHA204 CryptoAuthentication™ chip mounted. This chip contains information that identifies the extension with its name and some extra data. When an Xplained Pro extension board is connected to an Xplained Pro MCU board the information is read and sent to Atmel Studio. The Atmel Kits extension, installed with Atmel Studio, will give relevant information, code examples and links to relevant documents. Table 3-1, “Xplained Pro ID Chip Content” on page 5 shows the data fields stored in the ID chip with example content. Table 3-1. Xplained Pro ID Chip Content Data Field Data Type Example Content Manufacturer ASCII string Atmel’\0’ Product Name ASCII string Segment LCD1 Xplained Pro’\0’ Product Revision ASCII string 02’\0’ Product Serial Number ASCII string 1774020200000010’\0’ Minimum Voltage [mV] uint16_t 3000 Maximum Voltage [mV] uint16_t 3600 Maximum Current [mA] uint16_t 30 3.2 Standard headers and connectors 3.2.1 Xplained Pro Standard Extension Header All Xplained Pro kits have one or more dual row, 20 pin, 100mil extension headers. Xplained Pro MCU boards have male headers while Xplained Pro extensions have their female counterparts. Note that all pins are not always connected. However, all the connected pins follow the defined pin-out described in Table 3-2, “Xplained Pro Extension Header” on page 5. The extension headers can be used to connect a wide variety of Xplained Pro extensions to Xplained Pro MCU boards and to access the pins of the target MCU on Xplained Pro MCU board directly. Table 3-2. Xplained Pro Extension Header Pin number Name Description 1 ID Communication line to the ID chip on extension board. 2 GND Ground. 3 ADC(+) Analog to digital converter , alternatively positive part of differential ADC. 4 ADC(-) Analog to digital converter , alternatively negative part of differential ADC. 5 GPIO1 General purpose I/O. 6 GPIO2 General purpose I/O. 7 PWM(+) Pulse width modulation , alternatively positive part of differential PWM. 8 PWM(-) Pulse width modulation , alternatively positive part of differential PWM. 1 http://store.atmel.com/Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 6 Pin number Name Description 9 IRQ/GPIO Interrupt request line and/or general purpose I/O. 10 SPI_SS_B/GPIO Slave select for SPI and/or general purpose I/O. 11 TWI_SDA Data line for two wire interface. Always implemented, bus type. 12 TWI_SCL Clock line for two wire interface. Always implemented, bus type. 13 USART_RX Receiver line of Universal Synchronous and Asynchronous serial Receiver and Transmitter. 14 USART_TX Transmitter line of Universal Synchronous and Asynchronous serial Receiver and Transmitter. 15 SPI_SS_A Slave select for SPI. Should be unique if possible. 16 SPI_MOSI Master out slave in line of Serial peripheral interface. Always implemented, bus type. 17 SPI_MISO Master in slave out line of Serial peripheral interface. Always implemented, bus type. 18 SPI_SCK Clock for Serial peripheral interface. Always implemented, bus type. 19 GND Ground. 20 VCC Power for extension board.Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 7 4. Hardware user guide 4.1 Headers and connectors 4.1.1 OLED1 Xplained Pro extension header OLED1 Xplained Pro implements one Xplained Pro Standard Extension Header on page 5 marked with EXT in silkscreen. This header makes it possible to connect the board to any Xplained Pro MCU board. The pin-out definition for the extension header can be seen in Table 4-1, “OLED1 Xplained Pro extension header” on page 7. Table 4-1. OLED1 Xplained Pro extension header Pin Number Function Description 1 ID Communication line to ID chip 2 GND Ground 3 BUTTON2 Push button 2, active low 4 BUTTON3 Push button 3, active low 5 DATA_CMD_SEL Data / command select for OLED display. High = data, low = command. 6 LED3 LED3, active low 7 LED1 LED1, active low 8 LED2 LED2, active low 9 BUTTON1 Push button 1, active low 10 DISPLAY_RESET Reset line for OLED display, active low 11 NC 12 NC 13 NC 14 NC 15 DISPLAY_SS OLED display slave select, active low 16 SPI MOSI MOSI signal SPI connected to OLED display 17 NC 18 SPI SCK Clock signal for SPI connected to OLED display 19 GND Ground 20 VCC Target supply voltage 4.2 Peripherals 4.2.1 LEDs There are three yellow LEDs available on OLED1 Xplained Pro. The LEDs can be activated by driving the connected I/O line low. Table 4-2. LED connections Pin on EXT connector Silk screen marking 7 LED1 8 LED2 6 LED3 4.2.2 Push buttons There are three push buttons available on OLED1 Xplained Pro. When a button is pushed the corresponding IO pin is connected to ground. There are no external pull-up resistors on OLED1 Xplained Pro, so internal pullup resistors have to be enabled in the target microcontroller.Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 8 Note Remember to enable internal pull-up resistors in the target device to get a defined electrical level on the IO lines connected to the buttons. Table 4-3. Push button connections Pin on EXT connector Silk screen marking 9 BUTTON1 3 BUTTON2 4 BUTTON3 4.2.3 OLED display OLED1 Xplained Pro features a 128 x 32 pixel white monochrome OLED display, UG-2832HSWEG041 from WiseChip Semiconductor Inc. The display has a SSD1306 display controller by Solomon Systech built in and is controlled via a 4-wire SPI interface + reset with the signals described in Table 4-4, “OLED display connections” on page 8. The datasheets for the display module or the display controller is not publicly available and has to be acquired from the respective manufacturers. Note Note that the OLED display does not have a SPI MISO signal. That means that data can only be written to the display, not read. Table 4-4. OLED display connections Pin on EXT connector Signal Name Description 16 SPI_MOSI SPI master out, slave in signal. Used to write data to the display 18 SPI_SCK SPI clock signal, generated by the master. 5 DATA_CMD_SEL Data/command select. Used to choose whether the communication is data to the display memory or a command to the LCD controller. 15 DISPLAY_SS SPI slave select signal, must be held low during SPI communication. 10 DISPLAY_RESET Reset signal to the OLED display, active low. Used during initialization of the display. 1 http://www.wisechip.com.tw/english/Products_02-04.aspAtmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 9 5. Hardware revision history and known issues 5.1 Identifying product ID and revision The revision and product identifier of Xplained Pro boards can be found in two ways, through Atmel Studio or by looking at the sticker on the bottom side of the PCB. By connecting a Xplained Pro MCU board to a computer with Atmel Studio running, an information window will pop up. The first 6 digits of the serial number, which is listed under kit details, contain the product identifier and revision. Information about connected Xplained Pro extension boards will also appear in the Atmel Kits window. The same information can be found on the sticker on the bottom side of the PCB. Most kits will print the identifier and revision in plain text as A09-nnnn\rr where nnnn is the identifier and rr is the revision. Boards with limited space have a sticker with only a QR-code which contains a serial number string. The serial number string has the following format: "nnnnrrssssssssss" n = product identifier r = revision s = serial number The kit identifier for OLED1 Xplained Pro is 1769. 5.2 Revision 3 Revision 3 of OLED1 Xplained Pro is the initial released version. OLED1 Xplained Pro boards with a serial number that ends with a number lower than 11148 may have a wrong revision programmed into the Xplained Pro ID chip. This will only affect the information displayed by the Atmel Kits extension in Atmel Studio. It will not affect the operation of the board.Atmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 10 6. Document revision history Document revision Date Comment 42077B 09/2013 Added errata about revision 3 of the board. 42077A 25/02/2013 First releaseAtmel OLED1 Xplained Pro [USER GUIDE] 42077B-MCU-10/2013 11 7. Evaluation board/kit important notice This evaluation board/kit is intended for use for FURTHER ENGINEERING, DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY. It is not a finished product and may not (yet) comply with some or any technical or legal requirements that are applicable to finished products, including, without limitation, directives regarding electromagnetic compatibility, recycling (WEEE), FCC, CE or UL (except as may be otherwise noted on the board/kit). Atmel supplied this board/kit "AS IS," without any warranties, with all faults, at the buyer's and further users' sole risk. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies Atmel from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user's responsibility to take any and all appropriate precautions with regard to electrostatic discharge and any other technical or legal concerns. EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER USER NOR ATMEL SHALL BE LIABLE TO EACH OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. No license is granted under any patent right or other intellectual property right of Atmel covering or relating to any machine, process, or combination in which such Atmel products or services might be or are used.Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com © 2013 Atmel Corporation. All rights reserved. / Rev.: 42077B-MCU-10/2013 Atmel®, Atmel logo and combinations thereof, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. 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Atmel-8303H-AVR-ATtiny1634-Datasheet–02/2014 Features • High Performance, Low Power AVR® 8-bit Microcontroller • Advanced RISC Architecture – 125 Powerful Instructions – Most Single Clock Cycle Execution – 32 x 8 General Purpose Working Registers – Fully Static Operation • High Endurance, Non-volatile Memory Segments – 16K Bytes of In-System, Self-Programmable Flash Program Memory • Endurance: 10,000 Write/Erase Cycles – 256 Bytes of In-System Programmable EEPROM • Endurance: 100,000 Write/Erase Cycles – 1K Byte of Internal SRAM – Data retention: 20 years at 85C / 100 years at 25C – Programming Lock for Self-Programming Flash & EEPROM Data Security • Peripheral Features – Dedicated Hardware and QTouch® Library Support for Capacitive Touch Sensing – One 8-bit and One 16-bit Timer/Counter with Two PWM Channels, Each – 12-channel, 10-bit ADC – Programmable Ultra Low Power Watchdog Timer – On-chip Analog Comparator – Two Full Duplex USARTs with Start Frame Detection – Universal Serial Interface – Slave I2 C Serial Interface • Special Microcontroller Features – debugWIRE On-chip Debug System – In-System Programmable via SPI Port – Internal and External Interrupt Sources • Pin Change Interrupt on 18 Pins – Low Power Idle, ADC Noise Reduction, Standby and Power-down Modes – Enhanced Power-on Reset Circuit – Programmable Brown-out Detection Circuit with Supply Voltage Sampling – Calibrated 8MHz Oscillator with Temperature Calibration Option – Calibrated 32kHz Ultra Low Power Oscillator – On-chip Temperature Sensor • I/O and Packages – 18 Programmable I/O Lines – 20-pad QFN/MLF, and 20-pin SOIC • Operating Voltage: – 1.8 – 5.5V • Speed Grade: – 0 – 2MHz @ 1.8 – 5.5V – 0 – 8MHz @ 2.7 – 5.5V – 0 – 12MHz @ 4.5 – 5.5V • Temperature Range: -40C to +105C • Low Power Consumption – Active Mode: 0.2mA at 1.8V and 1MHz – Idle Mode: 30µA at 1.8V and 1MHz – Power-Down Mode (WDT Enabled): 1µA at 1.8V – Power-Down Mode (WDT Disabled): 100nA at 1.8V 8-bit Atmel tinyAVR Microcontroller with 16K Bytes In-System Programmable Flash ATtiny1634ATtiny1634 [DATASHEET] 2 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 1. Pin Configurations Figure 1-1. Pinout of ATtiny1634 1 2 3 4 5 QFN/MLF 15 14 13 12 11 20 19 18 17 16 6 7 8 9 10 NOTE Bottom pad should be soldered to ground. (PCINT1/AIN0) PA1 (PCINT0/AREF) PA0 GND VCC PC5 (XTAL1/CLKI/PCINT17) PC0 (ADC9/OC0A/XCK0/PCINT12) PC1 (ADC10/ICP1/SCL/USCK/XCK1/PCINT13) PC2 (ADC11/CLKO/INT0/PCINT14) PC3 (RESET/dW/PCINT15) PC4 (XTAL2/PCINT16) PA7 (PCINT7/RXD0/ADC4) PB0 (PCINT8/TXD0/ADC5) PB1 (ADC6/DI/SDA/RXD1/PCINT9) PB2 (ADC7/DO/TXD1/PCINT10) PB3 (ADC8/OC1A/PCINT11) (PCINT6/OC1B/ADC3) PA6 (PCINT5/OC0B/ADC2) PA5 (PCINT4/T0/ADC1) PA4 (PCINT3/T1/SNS/ADC0) PA3 (PCINT2/AIN1) PA2 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 (PCINT8/TXD0/ADC5) PB0 (PCINT7/RXD0/ADC4) PA7 (PCINT6/OC1B/ADC3) PA6 (PCINT5/OC0B/ADC2) PA5 (PCINT4/T0/ADC1) PA4 (PCINT3/T1/SNS/ADC0) PA3 (PCINT2/AIN1) PA2 (PCINT1/AIN0) PA1 (PCINT0/AREF) PA0 GND PB1 (ADC6/DI/SDA/RXD1/PCINT9) PB2 (ADC7/DO/TXD1/PCINT10) PB3 (ADC8/OC1A/PCINT11) PC0 (ADC9/OC0A/XCK0/PCINT12) PC1 (ADC10/ICP1/SCL/USCK/XCK1/PCINT13) PC2 (ADC11/CLKO/INT0/PCINT14) PC3 (RESET/dW/PCINT15) PC4 (XTAL2/PCINT16) PC5 (XTAL1/CLKI/PCINT17) VCC SOICATtiny1634 [DATASHEET] 3 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 1.1 Pin Descriptions 1.1.1 VCC Supply voltage. 1.1.2 GND Ground. 1.1.3 XTAL1 Input to the inverting amplifier of the oscillator and the internal clock circuit. This is an alternative pin configuration of PC5. 1.1.4 XTAL2 Output from the inverting amplifier of the oscillator. Alternative pin configuration of PC4. 1.1.5 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running and provided the reset pin has not been disabled. The minimum pulse length is given in Table 24-5 on page 231. Shorter pulses are not guaranteed to generate a reset. The reset pin can also be used as a (weak) I/O pin. 1.1.6 Port A (PA7:PA0) This is an 8-bit, bi-directional I/O port with internal pull-up resistors (selected for each bit). Output buffers have the following drive characteristics: • PA7, PA4:PA0: Symmetrical, with standard sink and source capability • PA6, PA5: Asymmetrical, with high sink and standard source capability As inputs, port pins that are externally pulled low will source current provided that pull-up resistors are activated. Port pins are tri-stated when a reset condition becomes active, even if the clock is not running. This port has alternate pin functions to serve special features of the device. See “Alternate Functions of Port A” on page 62. 1.1.7 Port B (PB3:PB0) This is a 4-bit, bi-directional I/O port with internal pull-up resistors (selected for each bit).Output buffers have the following drive characteristics: • PB3: Asymmetrical, with high sink and standard source capability • PB2:PB0: Symmetrical, with standard sink and source capability As inputs, port pins that are externally pulled low will source current provided that pull-up resistors are activated. Port pins are tri-stated when a reset condition becomes active, even if the clock is not running. This port has alternate pin functions to serve special features of the device. See “Alternate Functions of Port B” on page 65. 1.1.8 Port C (PC5:PC0) This is a 6-bit, bi-directional I/O port with internal pull-up resistors (selected for each bit). Output buffers have the following drive characteristics:ATtiny1634 [DATASHEET] 4 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 • PC5:PC1: Symmetrical, with standard sink and source capability • PC0: Asymmetrical, with high sink and standard source capability As inputs, port pins that are externally pulled low will source current provided that pull-up resistors are activated. Port pins are tri-stated when a reset condition becomes active, even if the clock is not running. This port has alternate pin functions to serve special features of the device. See “Alternate Functions of Port C” on page 67. 2. Overview ATtiny1634 is a low-power CMOS 8-bit microcontrollers based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny1634 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. Figure 2-1. Block Diagram DEBUG INTERFACE CALIBRATED ULP OSCILLATOR WATCHDOG TIMER CALIBRATED OSCILLATOR TIMING AND CONTROL VCC RESET GND 8-BIT DATA BUS CPU CORE PROGRAM MEMORY (FLASH) DATA MEMORY (SRAM) POWER SUPERVISION: POR BOD RESET ISP INTERFACE PORT A PORT B PORT C VOLTAGE REFERENCE MULTIPLEXER ANALOG COMPARATOR ADC TEMPERATURE SENSOR TWO-WIRE INTERFACE USART0 TOUCH SENSING EEPROM ON-CHIP DEBUGGER PA[7:0] PB[3:0] PC[5:0] 8-BIT TIMER/COUNTER 16-BIT TIMER/COUNTER USI USART1ATtiny1634 [DATASHEET] 5 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 The AVR core combines a rich instruction set with 32 general purpose working registers. All 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in a single instruction, executed in one clock cycle. The resulting architecture is compact and code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. ATtiny1634 provides the following features: • 16K bytes of in-system programmable Flash • 1K bytes of SRAM data memory • 256 bytes of EEPROM data memory • 18 general purpose I/O lines • 32 general purpose working registers • An 8-bit timer/counter with two PWM channels • A16-bit timer/counter with two PWM channels • Internal and external interrupts • A 10-bit ADC with 5 internal and 12 external channels • An ultra-low power, programmable watchdog timer with internal oscillator • Two programmable USART’s with start frame detection • A slave Two-Wire Interface (TWI) • A Universal Serial Interface (USI) with start condition detector • A calibrated 8MHz oscillator • A calibrated 32kHz, ultra low power oscillator • Four software selectable power saving modes. The device includes the following modes for saving power: • Idle mode: stops the CPU while allowing the timer/counter, ADC, analog comparator, SPI, TWI, and interrupt system to continue functioning • ADC Noise Reduction mode: minimizes switching noise during ADC conversions by stopping the CPU and all I/O modules except the ADC • Power-down mode: registers keep their contents and all chip functions are disabled until the next interrupt or hardware reset • Standby mode: the oscillator is running while the rest of the device is sleeping, allowing very fast start-up combined with low power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The Flash program memory can be re-programmed in-system through a serial interface, by a conventional non-volatile memory programmer or by an on-chip boot code, running on the AVR core. The ATtiny1634 AVR is supported by a full suite of program and system development tools including: C compilers, macro assemblers, program debugger/simulators and evaluation kits.ATtiny1634 [DATASHEET] 6 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 3. General Information 3.1 Resources A comprehensive set of drivers, application notes, data sheets and descriptions on development tools are available for download at http://www.atmel.com/avr. 3.2 Code Examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. For I/O Registers located in the extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with instructions that allow access to extended I/O. Typically, this means “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”. Note that not all AVR devices include an extended I/O map. 3.3 Capacitive Touch Sensing Atmel QTouch Library provides a simple to use solution for touch sensitive interfaces on Atmel AVR microcontrollers. The QTouch Library includes support for QTouch® and QMatrix® acquisition methods. Touch sensing is easily added to any application by linking the QTouch Library and using the Application Programming Interface (API) of the library to define the touch channels and sensors. The application then calls the API to retrieve channel information and determine the state of the touch sensor. The QTouch Library is free and can be downloaded from the Atmel website. For more information and details of implementation, refer to the QTouch Library User Guide – also available from the Atmel website. 3.4 Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C. 4. CPU Core This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts.ATtiny1634 [DATASHEET] 7 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 4.1 Architectural Overview Figure 4-1. Block Diagram of the AVR Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the Program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the Program memory. This concept enables instructions to be executed in every clock cycle. The Program memory is In-System Reprogrammable Flash memory. The fast-access Register File contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash Program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, capable of directly addressing the whole address space. Most AVR instructions have a single 16-bit word format but 32-bit wide instructions also exist. The actual instruction set varies, as some devices only implement a part of the instruction set. INTERRUPT UNIT STATUS AND CONTROL PROGRAM MEMORY (FLASH) DATA MEMORY (SRAM) PROGRAM COUNTER INSTRUCTION REGISTER INSTRUCTION DECODER CONTROL LINES GENERAL PURPOSE REGISTERS X Y Z ALU DIRECT ADDRESSING INDIRECT ADDRESSING 8-BIT DATA BUSATtiny1634 [DATASHEET] 8 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. In addition, the ATtiny1634 has Extended I/O Space from 0x60 - 0xFF in SRAM where only the ST/STS/STD and LD/LDS/LDD instructions can be used. 4.2 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bitfunctions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See external document “AVR Instruction Set” and “Instruction Set Summary” on page 278 section for more information. 4.3 Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. See external document “AVR Instruction Set” and “Instruction Set Summary” on page 278 section for more information. The Status Register is neither automatically stored when entering an interrupt routine, nor restored when returning from an interrupt. This must be handled by software. 4.4 General Purpose Register File The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 4-2 below shows the structure of the 32 general purpose working registers in the CPU.ATtiny1634 [DATASHEET] 9 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 4-2. General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 4-2, each register is also assigned a Data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y- and Z-pointer registers can be set to index any register in the file. 4.4.1 The X-register, Y-register, and Z-register The registers R26..R31 have added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 4-3 below. 7 0 Addr. Special Function R0 0x00 R1 0x01 R2 0x02 R3 0x03 … ... R12 0x0C R13 0x0D R14 0x0E R15 0x0F R16 0x10 R17 0x11 … ... R26 0x1A X-register Low Byte R27 0x1B X-register High Byte R28 0x1C Y-register Low Byte R29 0x1D Y-register High Byte R30 0x1E Z-register Low Byte R31 0x1F Z-register High ByteATtiny1634 [DATASHEET] 10 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 4-3. The X-, Y-, and Z-registers In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the instruction set reference for details). 4.5 Stack Pointer The stack is mainly used for storing temporary data, local variables and return addresses after interrupts and subroutine calls. The Stack Pointer registers (SPH and SPL) always point to the top of the stack. Note that the stack grows from higher memory locations to lower memory locations. This means that the PUSH instructions decreases and the POP instruction increases the stack pointer value. The stack pointer points to the area of data memory where subroutine and interrupt stacks are located. This stack space must be defined by the program before any subroutine calls are executed or interrupts are enabled. The pointer is decremented by one when data is put on the stack with the PUSH instruction, and incremented by one when data is fetched with the POP instruction. It is decremented by two when the return address is put on the stack by a subroutine call or a jump to an interrupt service routine, and incremented by two when data is fetched by a return from subroutine (the RET instruction) or a return from interrupt service routine (the RETI instruction). The AVR stack pointer is typically implemented as two 8-bit registers in the I/O register file. The width of the stack pointer and the number of bits implemented is device dependent. In some AVR devices all data memory can be addressed using SPL, only. In this case, the SPH register is not implemented. The stack pointer must be set to point above the I/O register areas, the minimum value being the lowest address of SRAM. See Table 5-2 on page 16. 4.6 Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 4-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. 15 0 X-register 7 XH 0 7 XL 0 R27 R26 15 0 Y-register 7 YH 0 7 YL 0 R29 R28 15 0 Z-register 7 ZH 0 7 ZL 0 R31 R30ATtiny1634 [DATASHEET] 11 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 4-4. The Parallel Instruction Fetches and Instruction Executions Figure 4-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 4-5. Single Cycle ALU Operation 4.7 Reset and Interrupt Handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate Program Vector in the Program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. The lowest addresses in the Program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 47. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPU Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPUATtiny1634 [DATASHEET] 12 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence. Note: See “Code Examples” on page 6. When using the SEI instruction to enable interrupts, the instruction following SEI will be executed before any pending interrupts, as shown in the following example. Note: See “Code Examples” on page 6. 4.7.1 Interrupt Response Time The interrupt execution response for all the enabled AVR interrupts is four clock cycles minimum. After four clock cycles the Program Vector address for the actual interrupt handling routine is executed. During this four clock cycle Assembly Code Example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMPE ; start EEPROM write sbi EECR, EEPE out SREG, r16 ; restore SREG value (I-bit) C Code Example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ _CLI(); EECR |= (1< 1MHz 12 – 22 pF XTAL2 XTAL1 GND C2 C1ATtiny1634 [DATASHEET] 29 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 The ripple counter that implements the prescaler runs at the frequency of the undivided clock, which may be faster than the CPU's clock frequency. Hence, it is not possible to determine the state of the prescaler - even if it were readable, and the exact time it takes to switch from one clock division to another cannot be exactly predicted. From the time the CLKPS values are written, it takes between T1 + T2 and T1 + 2*T2 before the new clock frequency is active. In this interval, 2 active clock edges are produced. Here, T1 is the previous clock period, and T2 is the period corresponding to the new prescaler setting. 6.4 Clock Output Buffer The device can output the system clock on the CLKO pin. To enable the output, the CKOUT_IO bit has to be programmed. The CKOUT fuse determines the initial value of the CKOUT_IO bit that is loaded to the CLKSR register when the device is powered up or has been reset. The clock output can be switched at run-time by setting the CKOUT_IO bit in CLKSR as described in chapter “CLKSR – Clock Setting Register” on page 29. This mode is suitable when the chip clock is used to drive other circuits on the system. Note that the clock will not be output during reset and that the normal operation of the I/O pin will be overridden when the fuse is programmed. Any clock source, including the internal oscillators, can be selected when the clock is output on CLKO. If the System Clock Prescaler is used, it is the divided system clock that is output. 6.5 Register Description 6.5.1 CLKSR – Clock Setting Register • Bit 7 – OSCRDY: Oscillator Ready This bit is set when oscillator time-out is complete. When OSCRDY is set the oscillator is stable and the clock source can be changed safely. • Bit 6 – CSTR: Clock Select Trigger This bit triggers the clock selection. It can be used to enable the oscillator in advance and select the clock source, before the oscillator is stable. If CSTR is set at the same time as the CKSEL bits are written, the contents are directly copied to the CKSEL register and the system clock is immediately switched. If CKSEL bits are written without setting CSTR, the oscillator selected by the CKSEL bits is enabled, but the system clock is not switched yet. • Bit 5 – CKOUT_IO: Clock Output This bit enables the clock output buffer. The CKOUT fuse determines the initial value of the CKOUT_IO bit that is loaded to the CLKSR register when the device is powered up or has been reset • Bit 4 – SUT: Start-Up Time The SUT and CKSEL bits define the start-up time of the device, as shown in Table 6-2, below. The initial value of the SUT bit is determined by the SUT fuse. The SUT fuse is loaded to the SUT bit when the device is powered up or has been reset. Bit 7 6 5 4 3 2 1 0 0x32 (0x52) OSCRDY CSTR CKOUT_IO SUT CKSEL3 CKSEL2 CKSEL1 CKSEL0 CLKSR Read/Write R W R R R/W R/W R/W R/W Initial Value 0 0 0 See Bit DescriptionATtiny1634 [DATASHEET] 30 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Note: 1. Device start-up time from power-down sleep mode. 2. When BOD has been disabled by software, the wake-up time from sleep mode will be approximately 60µs to ensure the BOD is working correctly before MCU continues executing code. 3. Device start-up time after reset. 4. The device is shipped with this option selected. 5. This option is not suitable for use with crystals. 6. This option should not be used when operating close to the maximum frequency of the device, and only if frequency stability at start-up is not important for the application. 7. This option is intended for use with ceramic resonators and will ensure frequency stability at start-up. It can also be used with crystals when not operating close to the maximum frequency of the device, and if frequency stability at start-up is not important for the application. • Bits 3:0 – CKSEL[3:0]: Clock Select Bits These bits select the clock source of the system clock and can be written at run-time. The clock system ensures glitch free switching of the clock source. CKSEL fuses determine the initial value of the CKSEL bits when the device is powered up or reset. The clock alternatives are shown in Table 6-3 below. Table 6-2. Device Start-up Times SUT CKSEL Clock From Power-Down (1)(2) From Reset (3) 0 (4) 0000 External 6 CK 22 CK + 16ms 0010 (4) Internal 8MHz 6 CK 20 CK + 16ms 0100 Internal 32kHz 6 CK 22 CK + 16ms 0001 0011 0101 ... 0111 Reserved 1XX0 Ceramic resonator (5) 258 CK (6) 274 CK + 16ms 1XX1 Crystal oscillator 16K CK 16K CK + 16 ms 1 0000 ... 0111 1XX1 Reserved 1XX0 Ceramic resonator 1K CK (7) 1K CK +16ms Table 6-3. Device Clocking Options CKSEL[3:0] (1) Frequency Device Clocking Option 0000 Any External Clock (see page 26) 0010 8MHz Calibrated Internal 8MHz Oscillator (see page 27) (2) 0100 32kHz Internal 32kHz Ultra Low Power (ULP) Oscillator (see page 27) 00X1 0101 ... 0111 — Reserved 100X 0.4...0.9MHz Crystal Oscillator / Ceramic Resonator (see page 27) 101X 0.9...3MHz 110X 3...8MHz 111X > 8MHzATtiny1634 [DATASHEET] 31 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Note: 1. For all fuses “1” means unprogrammed and “0” means programmed. 2. This is the default setting. The device is shipped with this fuse combination. To avoid unintentional switching of clock source, a protected change sequence must be followed to change the CKSEL bits, as follows: 1. Write the signature for change enable of protected I/O register to register CCP. 2. Within four instruction cycles, write the CKSEL bits with the desired value. 6.5.2 CLKPR – Clock Prescale Register • Bits 7:4 – Res: Reserved Bits These bits are reserved and will always read zero. • Bits 3:0 – CLKPS[3:0]: Clock Prescaler Select Bits 3 - 0 These bits define the division factor between the selected clock source and the internal system clock. These bits can be written run-time to vary the clock frequency to suit the application requirements. As the divider divides the master clock input to the MCU, the speed of all synchronous peripherals is reduced when a division factor is used. The division factors are given in Table 6-4 on page 31. To avoid unintentional changes of clock frequency, a protected change sequence must be followed to change the CLKPS bits: 1. Write the signature for change enable of protected I/O register to register CCP. 2. Within four instruction cycles, write the desired value to CLKPS bits. Interrupts must be disabled when changing prescaler setting to make sure the write procedure is not interrupted. Bit 7 6 5 4 3 2 1 0 0x33 (0x53) – – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 CLKPR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 See Bit Description Table 6-4. Clock Prescaler Select CLKPS3 CLKPS2 CLKPS1 CLKPS0 Clock Division Factor 0 0 0 0 1 (1) 0001 2 0010 4 0 0 1 1 8 (2) 0 1 0 0 16 0 1 0 1 32 0 1 1 0 64 0 1 1 1 128 1 0 0 0 256ATtiny1634 [DATASHEET] 32 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Note: 1. This is the initial value when CKDIV8 fuse has been unprogrammed. 2. This is the initial value when CKDIV8 fuse has been programmed. The device is shipped with the CKDIV8 Fuse programmed. The initial value of clock prescaler bits is determined by the CKDIV8 fuse (see Table 22-5 on page 210). When CKDIV8 is unprogrammed, the system clock prescaler is set to one and, when programmed, to eight. Any value can be written to the CLKPS bits regardless of the CKDIV8 fuse bit setting. When CKDIV8 is programmed the initial value of CLKPS bits give a clock division factor of eight at start up. This is useful when the selected clock source has a higher frequency than allowed under present operating conditions. See “Speed” on page 229. 6.5.3 OSCCAL0 – Oscillator Calibration Register Although temperature slope and frequency are in part controlled by registers OSCTCAL0A and OSCTCAL0B it is possible to replace factory calibration by simply writing to this register alone. Optimal accuracy is achieved when OSCCAL0, OSCTAL0A and OSCTCAL0B are calibrated together. • Bits 7:0 – CAL0[7:0]: Oscillator Calibration Value The oscillator calibration register is used to trim the internal 8MHz oscillator and to remove process variations from the oscillator frequency. A pre-programmed calibration value is automatically written to this register during chip reset, giving the factory calibrated frequency specified in Table 24-2 on page 230. The application software can write this register to change the oscillator frequency. The oscillator can be calibrated to frequencies specified in Table 24-2 on page 230. Calibration outside that range is not guaranteed. The lowest oscillator frequency is reached by programming these bits to zero. Increasing the register value increases the oscillator frequency. A typical frequency response curve is shown in “Calibrated Oscillator Frequency (Nominal = 8MHz) vs. OSCCAL Value” on page 273. Note that this oscillator is used to time EEPROM and Flash write accesses, and write times will be affected accordingly. Do not calibrate to more than 8.8MHz if EEPROM or Flash is to be written. Otherwise, the EEPROM or Flash write may fail. To ensure stable operation of the MCU the calibration value should be changed in small steps. A step change in frequency of more than 2% from one cycle to the next can lead to unpredictable behavior. Also, the difference between two consecutive register values should not exceed 0x20. If these limits are exceeded the MCU must be kept in reset during changes to clock frequency. 1001 Reserved 1010 1011 1100 1101 1110 1111 Table 6-4. Clock Prescaler Select (Continued) CLKPS3 CLKPS2 CLKPS1 CLKPS0 Clock Division Factor Bit 7 6 5 4 3 2 1 0 (0x63) CAL07 CAL06 CAL05 CAL04 CAL03 CAL02 CAL01 CAL00 OSCCAL0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value Device Specific Calibration ValueATtiny1634 [DATASHEET] 33 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 6.5.4 OSCTCAL0A – Oscillator Temperature Calibration Register A This register is used for changing the temperature slope and frequency of the internal 8MHz oscillator. A pre-programmed calibration value is automatically written to this register during chip reset, giving the factory calibrated frequency specified in Table 24-2 on page 230. This register need not be updated if factory defaults in OSCCAL0 are overwritten although optimal accuracy is achieved when OSCCAL0, OSCTAL0A and OSCTCAL0B are calibrated together. • Bit 7 – Sign of Oscillator Temperature Calibration Value This is the sign bit of the calibration data. • Bits 6:0 – Oscillator Temperature Calibration Value These bits contain the numerical value of the calibration data. 6.5.5 OSCTCAL0B – Oscillator Temperature Calibration Register B A pre-programmed calibration value is automatically written to this register during chip reset, giving the factory calibrated frequency specified in Table 24-2 on page 230. This register need not be updated if factory defaults in OSCCAL0 are overwritten although optimal accuracy is achieved when OSCCAL0, OSCTAL0A and OSCTCAL0B are calibrated together. • Bit 7 – Temperature Compensation Enable When this bit is set the contents of registers OSCTCAL0A and OSCTCAL0B are used for calibration. When this bit is cleared the temperature compensation hardware is disabled and registers OSCTCAL0A and OSCTCAL0B have no effect on the frequency of the internal 8MHz oscillator. Note that temperature compensation has a large effect on oscillator frequency and, hence, when enabled or disabled the OSCCAL0 register must also be adjusted to compensate for this effect. • Bits 6:0 – Temperature Compensation Step Adjust These bits control the step size of the calibration data in OSCTCAL0A. The largest step size is achieved for 0x00 and smallest step size for 0x7F. 6.5.6 OSCCAL1 – Oscillator Calibration Register • Bits 7:2 – Res: Reserved Bits These bits are reserved and will always read zero. Bit 7 6 5 4 3 2 1 0 (0x64) Oscillator Temperature Calibration Data OSCTCAL0A Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value Device Specific Calibration Value Bit 7 6 5 4 3 2 1 0 (0x65) Oscillator Temperature Calibration Data OSCTCAL0B Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value Device Specific Calibration Value Bit 7 6 5 4 3 2 1 0 (0x66) – – – – – – CAL11 CAL10 OSCCAL1 Read/Write R R R R R R R/W R/W Initial Value Device Specific Calibration ValueATtiny1634 [DATASHEET] 34 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 • Bits 1:0 – CAL1[1:0]: Oscillator Calibration Value The oscillator calibration register is used to trim the internal 32kHz oscillator and to remove process variations from the oscillator frequency. A pre-programmed calibration value is automatically written to this register during chip reset, giving the factory calibrated frequency as specified in Table 24-3 on page 231. The application software can write this register to change the oscillator frequency. The oscillator can be calibrated to frequencies as specified in Table 24-3 on page 231. Calibration outside that range is not guaranteed. The lowest oscillator frequency is reached by programming these bits to zero. Increasing the register value increases the oscillator frequency. 7. Power Management and Sleep Modes The high performance and industry leading code efficiency makes the AVR microcontrollers an ideal choise for low power applications. In addition, sleep modes enable the application to shut down unused modules in the MCU, thereby saving power. The AVR provides various sleep modes allowing the user to tailor the power consumption to the application’s requirements. 7.1 Sleep Modes Figure 6-1 on page 25 presents the different clock systems and their distribution in ATtiny1634. The figure is helpful in selecting an appropriate sleep mode. Table 7-1 shows the different sleep modes and the sources that may be used for wake up. Note: 1. Start frame detection, only. 2. Start condition, only. 3. Address match interrupt, only. 4. For INT0 level interrupt, only. To enter a sleep mode, the SE bit in MCUCR must be set and a SLEEP instruction must be executed. The SMn bits in MCUCR select which sleep mode will be activated by the SLEEP instruction. See Table 7-2 on page 37 for a summary. If an enabled interrupt occurs while the MCU is in a sleep mode, the MCU wakes up. The MCU is then halted for four cycles in addition to the start-up time, executes the interrupt routine, and resumes execution from the instruction following SLEEP. The contents of the Register File and SRAM are unaltered when the device wakes up from sleep. If a reset occurs during sleep mode, the MCU wakes up and executes from the Reset Vector. Table 7-1. Active Clock Domains and Wake-up Sources in Different Sleep Modes Sleep Mode Oscillators Active Clock Domains Wake-up Sources Main Clock Source Enabled clkCPU clkFLASH clkIO clkADC Watchdog Interrupt INT0 and Pin Change SPM/EEPROM Ready Interrupt ADC Interrupt USART USI TWI Slave Other I/O Idle X X X X X X X X X X X ADC Noise Reduction X X X X (4) X X X (1) X (2) X (3) Standby X X X (4) X (1) X (2) X (3) Power-down X X (4) X (1) X (2) X (3)ATtiny1634 [DATASHEET] 35 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Note that if a level triggered interrupt is used for wake-up the changed level must be held for some time to wake up the MCU (and for the MCU to enter the interrupt service routine). See “External Interrupts” on page 48 for details. 7.1.1 Idle Mode This sleep mode basically halts clkCPU and clkFLASH, while allowing other clocks to run. In Idle Mode, the CPU is stopped but the following peripherals continue to operate: • Watchdog and interrupt system • Analog comparator, and ADC • USART, TWI, and timer/counters Idle mode allows the MCU to wake up from external triggered interrupts as well as internal ones, such as Timer Overflow. If wake-up from the analog comparator interrupt is not required, the analog comparator can be powered down by setting the ACD bit in ACSRA. See “ACSRA – Analog Comparator Control and Status Register” on page 182. This will reduce power consumption in Idle mode. If the ADC is enabled, a conversion starts automatically when this mode is entered. 7.1.2 ADC Noise Reduction Mode This sleep mode halts clkI/O, clkCPU, and clkFLASH, while allowing other clocks to run. In ADC Noise Reduction mode, the CPU is stopped but the following peripherals continue to operate: • Watchdog (if enabled), and external interrupts • ADC • USART start frame detector, and TWI This improves the noise environment for the ADC, enabling higher resolution measurements. If the ADC is enabled, a conversion starts automatically when this mode is entered. The following events can wake up the MCU: • Watchdog reset, external reset, and brown-out reset • External level interrupt on INT0, and pin change interrupt • ADC conversion complete interrupt, and SPM/EEPROM ready interrupt • USI start condition, USART start frame detection, and TWI address match 7.1.3 Power-Down Mode This sleep mode halts all generated clocks, allowing operation of asynchronous modules, only. In Power-down Mode the oscillator is stopped, while the following peripherals continue to operate: • Watchdog (if enabled), external interrupts The following events can wake up the MCU: • Watchdog reset, external reset, and brown-out reset • External level interrupt on INT0, and pin change interrupt • USI start condition, USART start frame detection, and TWI address matchATtiny1634 [DATASHEET] 36 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 7.1.4 Standby Mode Standby Mode is identical to power-down, with the exception that the oscillator is kept running. From Standby mode, the device wakes up in six clock cycles. 7.2 Power Reduction Register The Power Reduction Register (PRR), see “PRR – Power Reduction Register” on page 38, provides a method to reduce power consumption by stopping the clock to individual peripherals. When the clock for a peripheral is stopped then: • The current state of the peripheral is frozen. • The associated registers can not be read or written. • Resources used by the peripheral will remain occupied. The peripheral should in most cases be disabled before stopping the clock. Clearing the PRR bit wakes up the peripheral and puts it in the same state as before shutdown. Peripheral shutdown can be used in Idle mode and Active mode to significantly reduce the overall power consumption. In all other sleep modes, the clock is already stopped. 7.3 Minimizing Power Consumption There are several issues to consider when trying to minimize the power consumption in an AVR controlled system. In general, sleep modes should be used as much as possible, and the sleep mode should be selected so that as few as possible of the device’s functions are operating. All functions not needed should be disabled. In particular, the following modules may need special consideration when trying to achieve the lowest possible power consumption. 7.3.1 Analog to Digital Converter If enabled, the ADC will be enabled in all sleep modes. To save power, the ADC should be disabled before entering any sleep mode. When the ADC is turned off and on again, the next conversion will be an extended conversion. See “Analog to Digital Converter” on page 185 for details on ADC operation. 7.3.2 Analog Comparator When entering Idle mode, the Analog Comparator should be disabled if not used. When entering ADC Noise Reduction mode, the Analog Comparator should be disabled. In the other sleep modes, the Analog Comparator is automatically disabled. However, if the Analog Comparator is set up to use the Internal Voltage Reference as input, the Analog Comparator should be disabled in all sleep modes. Otherwise, the Internal Voltage Reference will be enabled, independent of sleep mode. See “Analog Comparator” on page 181 for details on how to configure the Analog Comparator. 7.3.3 Brown-out Detector If the Brown-out Detector is not needed in the application, this module should be turned off. If the Brown-out Detector is enabled by the BODPD Fuses, it will be enabled in all sleep modes, and hence, always consume power. In the deeper sleep modes, this will contribute significantly to the total current consumption. If the Brown-out Detector is needed in the application, this module can also be set to Sampled BOD mode to save power. See “Brown-Out Detection” on page 41 for details on how to configure the Brown-out Detector. 7.3.4 Internal Voltage Reference The Internal Voltage Reference will be enabled when needed by the Brown-out Detection, the Analog Comparator or the ADC. If these modules are disabled as described in the sections above, the internal voltage reference will be disabled and it will not be consuming power. When turned on again, the user must allow the reference to start upATtiny1634 [DATASHEET] 37 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 before the output is used. If the reference is kept on in sleep mode, the output can be used immediately. See Internal Bandgap Reference in Table 24-5 on page 231 for details on the start-up time. 7.3.5 Watchdog Timer If the Watchdog Timer is not needed in the application, this module should be turned off. If the Watchdog Timer is enabled, it will be enabled in all sleep modes, and hence, always consume power. In the deeper sleep modes, this will contribute to the total current consumption. See “Watchdog Timer” on page 43 for details on how to configure the Watchdog Timer. 7.3.6 Port Pins When entering a sleep mode, all port pins should be configured to use minimum power. The most important thing is then to ensure that no pins drive resistive loads. In sleep modes where both the I/O clock (clkI/O) and the ADC clock (clkADC) are stopped, the input buffers of the device will be disabled. This ensures that no power is consumed by the input logic when not needed. In some cases, the input logic is needed for detecting wake-up conditions, and it will then be enabled. See the section “Digital Input Enable and Sleep Modes” on page 58 for details on which pins are enabled. If the input buffer is enabled and the input signal is left floating or has an analog signal level close to VCC/2, the input buffer will use excessive power. For analog input pins, the digital input buffer should be disabled at all times. An analog signal level close to VCC/2 on an input pin can cause significant current even in active mode. Digital input buffers can be disabled by writing to the Digital Input Disable Register (DIDR0). See “DIDR0 – Digital Input Disable Register 0” on page 200 for details. 7.3.7 On-chip Debug System If the On-chip debug system is enabled by the DWEN Fuse and the chip enters sleep mode, the main clock source is enabled and hence always consumes power. In the deeper sleep modes, this will contribute significantly to the total current consumption. 7.4 Register Description 7.4.1 MCUCR – MCU Control Register The MCU Control Register contains control bits for power management. • Bits 7, 3:2 – Res: Reserved Bits These bits are reserved and will always read zero. • Bits 6:5 – SM[1:0]: Sleep Mode Select Bits 1 and 0 These bits select between available sleep modes, as shown in Table 7-2. Bit 7 6 5 4 3 2 1 0 0x36 (0x56) – SM1 SM0 SE – – ISC01 ISC00 MCUCR Read/Write R R/W R/W R/W R R R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 7-2. Sleep Mode Select SM1 SM0 Sleep Mode 0 0 Idle 0 1 ADC Noise Reduction 1 0 Power-down 1 1 Standby(1)ATtiny1634 [DATASHEET] 38 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Note: 1. Only recommended with external crystal or resonator selected as clock source • Bit 4 – SE: Sleep Enable The SE bit must be written to logic one to make the MCU enter the sleep mode when the SLEEP instruction is executed. To avoid the MCU entering the sleep mode unless it is the programmer’s purpose, it is recommended to write the Sleep Enable (SE) bit to one just before the execution of the SLEEP instruction and to clear it immediately after waking up. 7.4.2 PRR – Power Reduction Register The Power Reduction Register provides a method to reduce power consumption by allowing peripheral clock signals to be disabled. • Bit 7 – Res: Reserved Bit This bit is a reserved bit and will always read zero. • Bit 6 – PRTWI: Power Reduction Two-Wire Interface Writing a logic one to this bit shuts down the Two-Wire Interface module. • Bit 5 – PRTIM1: Power Reduction Timer/Counter1 Writing a logic one to this bit shuts down the Timer/Counter1 module. When the Timer/Counter1 is enabled, operation will continue like before the shutdown. • Bit 4 – PRTIM0: Power Reduction Timer/Counter0 Writing a logic one to this bit shuts down the Timer/Counter0 module. When the Timer/Counter0 is enabled, operation will continue like before the shutdown. • Bit 3 – PRUSI: Power Reduction USI Writing a logic one to this bit shuts down the USI by stopping the clock to the module. When waking up the USI again, the USI should be re initialized to ensure proper operation. • Bit 2 – PRUSART1: Power Reduction USART1 Writing a logic one to this bit shuts down the USART1 module. When the USART1 is enabled, operation will continue like before the shutdown. • Bit 1 – PRUSART0: Power Reduction USART0 Writing a logic one to this bit shuts down the USART0 module. When the USART0 is enabled, operation will continue like before the shutdown. • Bit 0 – PRADC: Power Reduction ADC Writing a logic one to this bit shuts down the ADC. The ADC must be disabled before shut down. The analog comparator cannot be used when the ADC is shut down. Bit 7 6 5 4 3 2 1 0 0x34 (0x54) – PRTWI PRTIM1 PRTIM0 PRUSI PRUSART1 PRUSART0 PRADC PRR Read/Write R R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny1634 [DATASHEET] 39 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 8. System Control and Reset 8.1 Resetting the AVR During reset, all I/O registers are set to their initial values, and the program starts execution from the Reset Vector. The instruction placed at the Reset Vector should be a JMP (two-word, direct jump) instruction to the reset handling routine, although other one- or two-word jump instructions can be used. If the program never enables an interrupt source, the interrupt vectors are not used, and regular program code can be placed at these locations. The circuit diagram in Figure 8-1 shows the reset logic. Electrical parameters of the reset circuitry are defined in section “System and Reset” on page 231. Figure 8-1. Reset Logic The I/O ports of the AVR are immediately reset to their initial state when a reset source goes active. This does not require any clock source to be running. After all reset sources have gone inactive, a delay counter is invoked, stretching the internal reset. This allows the power to reach a stable level before normal operation starts. 8.2 Reset Sources The ATtiny1634 has four sources of reset: • Power-on Reset. The MCU is reset when the supply voltage is below the Power-on Reset threshold (VPOT) • External Reset. The MCU is reset when a low level is present on the RESET pin for longer than the minimum pulse length when RESET function is enabled • Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and the Watchdog is enabled • Brown-out Reset. The MCU is reset when the supply voltage VCC is below the Brown-out Reset threshold (VBOT) and the Brown-out Detector is enabled 8.2.1 Power-on Reset A Power-on Reset (POR) pulse is generated by an on-chip detection circuit. The detection level is defined in “System and Reset” on page 231. The POR is activated whenever VCC is below the detection level. The POR circuit can be used to trigger the Start-up Reset, as well as to detect a failure in supply voltage. A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the Power-on Reset threshold voltage invokes the delay counter, which determines how long the device is kept in reset after VCC rise. The reset signal is activated again, without any delay, when VCC decreases below the detection level. DATA BUS RESET FLAG REGISTER RESET FLAG REGISTER (RSTFLR) (RSTFLR) POWER-ON POWER-ON RESET CIRCUIT RESET CIRCUIT PULL-UP PULL-UP RESISTOR RESISTOR BODLEVEL2...0 BODLEVEL2...0 VCC SPIKE FILTER RESET EXTERNAL EXTERNAL RESET CIRCUIT RESET CIRCUIT BROWN OUT BROWN OUT RESET CIRCUIT RESET CIRCUIT RSTDISBL RSTDISBL WATCHDOG WATCHDOG TIMER DELAY COUNTERS COUNTERS S R Q WATCHDOG WATCHDOG OSCILLATOR OSCILLATOR CLOCK GENERATOR GENERATOR BORF PORF EXTRF WDRF INTERNAL INTERNAL RESET CK TIMEOUT TIMEOUT COUNTER RESET COUNTER RESETATtiny1634 [DATASHEET] 40 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 8-2. MCU Start-up, RESET Tied to VCC Figure 8-3. MCU Start-up, RESET Extended Externally 8.2.2 External Reset An External Reset is generated by a low level on the RESET pin if enabled. Reset pulses longer than the minimum pulse width (see section “System and Reset” on page 231) will generate a reset, even if the clock is not running. Shorter pulses are not guaranteed to generate a reset. When the applied signal reaches the Reset Threshold Voltage – VRST – on its positive edge, the delay counter starts the MCU after the time-out period – tTOUT – has expired. External reset is ignored during Power-on start-up count. After Power-on reset the internal reset is extended only if RESET pin is low when the initial Power-on delay count is complete. See Figure 8-2 and Figure 8-3. Figure 8-4. External Reset During Operation V TIME-OUT RESET RESET TOUT INTERNAL t VPOT VRST CC V TIME-OUT TOUT TOUT INTERNAL CC t VPOT VRST > t RESET RESET CCATtiny1634 [DATASHEET] 41 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 8.2.3 Watchdog Reset When the Watchdog times out, it will generate a short reset pulse. On the falling edge of this pulse, the delay timer starts counting the time-out period tTOUT. See page 43 for details on operation of the Watchdog Timer and Table 24-5 on page 231 for details on reset time-out. Figure 8-5. Watchdog Reset During Operation 8.2.4 Brown-Out Detection The Brown-Out Detection (BOD) circuit monitors that the VCC level is kept above a configurable trigger level, VBOT. When the BOD is enabled, a BOD reset will be given when VCC falls and remains below the trigger level for the length of the detection time, tBOD. The reset is kept active until VCC again rises above the trigger level. Figure 8-6. Brown-out Detection reset. The BOD circuit will not detect a drop in VCC unless the voltage stays below the trigger level for the detection time, tBOD (see “System and Reset” on page 231). The BOD circuit has three modes of operation: • Disabled: In this mode of operation VCC is not monitored and, hence, it is recommended only for applications where the power supply remains stable. CK CC VCC TIME-OUT INTERNAL RESET VBOTVBOT+ t TOUT t BODATtiny1634 [DATASHEET] 42 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 • Enabled: In this mode the VCC level is continuously monitored. If VCC drops below VBOT for at least tBOD a brown-out reset will be generated. • Sampled: In this mode the VCC level is sampled on each negative edge of a 1kHz clock that has been derived from the 32kHz ULP oscillator. Between each sample the BOD is turned off. Compared to the mode where BOD is constantly enabled this mode of operation reduces power consumption but fails to detect drops in VCC between two positive edges of the 1kHz clock. When a brown-out is detected in this mode, the BOD circuit is set to enabled mode to ensure that the device is kept in reset until VCC has risen above VBOT . The BOD will return to sampled mode after reset has been released and the fuses have been read in. The BOD mode of operation is selected using BODACT and BODPD fuse bits. The BODACT fuse bits determine how the BOD operates in active and idle mode, as shown in Table 8-1. The BODPD fuse bits determine the mode of operation in all sleep modes except idle mode, as shown in Table 8- 2. See “Fuse Bits” on page 209. 8.3 Internal Voltage Reference ATtiny1634 features an internal bandgap reference. This reference is used for Brown-out Detection, and it can be used as an input to the Analog Comparator or the ADC. The bandgap voltage varies with supply voltage and temperature. 8.3.1 Voltage Reference Enable Signals and Start-up Time The voltage reference has a start-up time that may influence the way it should be used. The start-up time is given in “System and Reset” on page 231. To save power, the reference is not always turned on. The reference is on during the following situations: 1. When the BOD is enabled (see “Brown-Out Detection” on page 41). 2. When the internal reference is connected to the Analog Comparator (by setting the ACBG bit in ACSRA). 3. When the ADC is enabled. Thus, when the BOD is not enabled, after setting the ACBG bit or enabling the ADC, the user must always allow the reference to start up before the output from the Analog Comparator or ADC is used. To reduce power conTable 8-1. Setting BOD Mode of Operation in Active and Idle Modes BODACT1 BODACT0 Mode of Operation 0 0 Reserved 0 1 Sampled 1 0 Enabled 1 1 Disabled Table 8-2. Setting BOD Mode of Operation in Sleep Modes Other Than Idle BODPD1 BODPD0 Mode of Operation 0 0 Reserved 0 1 Sampled 1 0 Enabled 1 1 DisabledATtiny1634 [DATASHEET] 43 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 sumption in Power-down mode, the user can avoid the three conditions above to ensure that the reference is turned off before entering Power-down mode. 8.4 Watchdog Timer The Watchdog Timer is clocked from the internal 32kHz ultra low power oscillator (see page 27). By controlling the Watchdog Timer prescaler, the Watchdog Reset interval can be adjusted as shown in Table 8-5 on page 46. The WDR – Watchdog Reset – instruction resets the Watchdog Timer. The Watchdog Timer is also reset when it is disabled and when a Chip Reset occurs. Ten different clock cycle periods can be selected to determine the reset period. If the reset period expires without another Watchdog Reset, the ATtiny1634 resets and executes from the Reset Vector. For timing details on the Watchdog Reset, refer to Table 8-5 on page 46. The Wathdog Timer can also be configured to generate an interrupt instead of a reset. This can be very helpful when using the Watchdog to wake-up from Power-down. To prevent unintentional disabling of the Watchdog or unintentional change of time-out period, two different safety levels are selected by the fuse WDTON as shown in Table 8-3 See “Timed Sequences for Changing the Configuration of the Watchdog Timer” on page 43 for details. Figure 8-7. Watchdog Timer 8.4.1 Timed Sequences for Changing the Configuration of the Watchdog Timer The sequence for changing configuration differs slightly between the two safety levels. Separate procedures are described for each level. • Safety Level 1 In this mode, the Watchdog Timer is initially disabled, but can be enabled by writing the WDE bit to one without any restriction. A timed sequence is needed when disabling an enabled Watchdog Timer. To disable an enabled Watchdog Timer, the following procedure must be followed: Table 8-3. WDT Configuration as a Function of the Fuse Settings of WDTON WDTON Safety Level WDT Initial State How to Disable the WDT How to Change Timeout Unprogrammed 1 Disabled Timed sequence No limitations Programmed 2 Enabled Always enabled Timed sequence OSC/512 OSC/1K OSC/2K OSC/4K OSC/8K OSC/16K OSC/32K OSC/64K OSC/128K OSC/256K MCU RESET WATCHDOG PRESCALER 32 kHz ULP OSCILLATOR WATCHDOG RESET WDP0 WDP1 WDP2 WDP3 WDE MUXATtiny1634 [DATASHEET] 44 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 a. Write the signature for change enable of protected I/O registers to register CCP b. Within four instruction cycles, in the same operation, write WDE and WDP bits • Safety Level 2 In this mode, the Watchdog Timer is always enabled, and the WDE bit will always read as one. A timed sequence is needed when changing the Watchdog Time-out period. To change the Watchdog Time-out, the following procedure must be followed: a. Write the signature for change enable of protected I/O registers to register CCP b. Within four instruction cycles, write the WDP bit. The value written to WDE is irrelevant 8.4.2 Code Examples The following code example shows how to turn off the WDT. The example assumes that interrupts are controlled (e.g., by disabling interrupts globally) so that no interrupts will occur during execution of these functions. Note: See “Code Examples” on page 6. 8.5 Register Description 8.5.1 MCUSR – MCU Status Register The MCU Status Register provides information on which reset source caused an MCU Reset. • Bits 7:4 – Res: Reserved Bits These bits are reserved bits in the ATtiny1634 and will always read as zero. • Bit 3 – WDRF: Watchdog Reset Flag This bit is set if a Watchdog Reset occurs. The bit is reset by a Power-on Reset, or by writing a logic zero to the flag. Assembly Code Example WDT_off: wdr ; Clear WDRF in RSTFLR in r16, RSTFLR andi r16, ~(1< ; Address 0x0038 ...ATtiny1634 [DATASHEET] 49 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 The pin change interrupts trigger as follows: • Pin Change Interrupt 0 (PCI0): triggers if any enabled PCINT[7:0] pin toggles • Pin Change Interrupt 1 (PCI1): triggers if any enabled PCINT[11:8] pin toggles • Pin Change Interrupt 2 (PCI2): triggers if any enabled PCINT[17:12] pin toggles Registers PCMSK0, PCMSK1, and PCMSK2 control which pins contribute to the pin change interrupts. Pin change interrupts on PCINT[17:0] are detected asynchronously, which means that these interrupts can be used for waking the part also from sleep modes other than Idle mode. External interrupt INT0 can be triggered by a falling or rising edge, or a low level. See “MCUCR – MCU Control Register” on page 37. When INT0 is enabled and configured as level triggered, the interrupt will trigger as long as the pin is held low. Note that recognition of falling or rising edge interrupts on INT0 requires the presence of an I/O clock, as described in “Clock System” on page 24. 9.2.1 Low Level Interrupt A low level interrupt on INT0 is detected asynchronously. This means that the interrupt source can be used for waking the part also from sleep modes other than Idle (the I/O clock is halted in all sleep modes except Idle). Note that if a level triggered interrupt is used for wake-up from Power-down, the required level must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If the level disappears before the end of the Start-up Time, the MCU will still wake up, but no interrupt will be generated. The start-up time is defined by the SUT and CKSEL fuses, as described in “Clock System” on page 24. If the low level on the interrupt pin is removed before the device has woken up then program execution will not be diverted to the interrupt service routine but continue from the instruction following the SLEEP command. 9.2.2 Pin Change Interrupt Timing A timing example of a pin change interrupt is shown in Figure 9-1.ATtiny1634 [DATASHEET] 50 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 9-1. Timing of pin change interrupts clk PCINT(0) pin_lat pin_sync pcint_in_(0) pcint_syn pcint_setflag PCIF PCINT(0) pin_sync pcint_syn pin_lat D Q LE pcint_setflag PCIF clk clk PCINT(0) in PCMSK(x) pcint_in_(0) 0 xATtiny1634 [DATASHEET] 51 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 9.3 Register Description 9.3.1 MCUCR – MCU Control Register • Bits 1:0 – ISC0[1:0]: Interrupt Sense Control 0 Bit 1 and Bit 0 External Interrupt 0 is triggered by activity on pin INT0, provided that the SREG I-flag and the corresponding interrupt mask are set. The conditions required to trigger the interrupt are defined in Table 9-2. Note: 1. If low level interrupt is selected, the low level must be held until the completion of the currently executing instruction to generate an interrupt. 2. The value on the INT0 pin is sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. 9.3.2 GIMSK – General Interrupt Mask Register • Bits 7, 2:0 – Res: Reserved Bits These bits are reserved and will always read zero. • Bit 6 – INT0: External Interrupt Request 0 Enable The external interrupt for pin INT0 is enabled when this bit and the I-bit in the Status Register (SREG) are set. The trigger conditions are set with the ISC0n bits. Activity on the pin will cause an interrupt request even if INT0 has been configured as an output. • Bit 5 – PCIE2: Pin Change Interrupt Enable 2 When this bit and the I-bit of SREG are set the Pin Change Interrupt 2 is enabled. Any change on an enabled PCINT[17:12] pin will cause a PCINT2 interrupt. See Table 9-1 on page 47. Each pin can be individually enabled. See “PCMSK2 – Pin Change Mask Register 2” on page 52. • Bit 4 – PCIE1: Pin Change Interrupt Enable 1 When this bit and the I-bit of SREG are set the Pin Change Interrupt 1 is enabled. Any change on an enabled PCINT[11:8] pin will cause a PCINT1 interrupt. See Table 9-1 on page 47. Each pin can be individually enabled. See “PCMSK1 – Pin Change Mask Register 1” on page 53. Bit 7 6 5 4 3 2 1 0 0x36 (0x56) – SM1 SM0 SE – – ISC01 ISC00 MCUCR Read/Write R R/W R/W R/W R R R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 9-2. External Interrupt 0 Sense Control ISC01 ISC00 Description 0 0 The low level of INT0 generates an interrupt request (1) 0 1 Any logical change on INT0 generates an interrupt request (2) 1 0 The falling edge of INT0 generates an interrupt request (2) 1 1 The rising edge of INT0 generates an interrupt request (2) Bit 7 6 5 4 3 2 1 0 0x3C (0x5C) – INT0 PCIE2 PCIE1 PCIE0 – – – GIMSK Read/Write R R/W R/W R/W R/W R R R Initial Value 0 0 0 0 0 0 0 0ATtiny1634 [DATASHEET] 52 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 • Bit 3 – PCIE0: Pin Change Interrupt Enable 0 When this bit and the I-bit of SREG are set the Pin Change Interrupt 0 is enabled. Any change on an enabled PCINT[7:0] pin will cause a PCINT0 interrupt. See Table 9-1 on page 47. Each pin can be individually enabled. See “PCMSK0 – Pin Change Mask Register 0” on page 53. 9.3.3 GIFR – General Interrupt Flag Register • Bits 7, 2:0 – Res: Reserved Bits These bits are reserved and will always read as zero. • Bit 6 – INTF0: External Interrupt Flag 0 This bit is set when activity on INT0 has triggered an interrupt request. Provided that the I-bit in SREG and the INT0 bit in GIMSK are set, the MCU will jump to the corresponding interrupt vector. The flag is cleared when the interrupt service routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. This flag is always cleared when INT0 is configured as a level interrupt. • Bit 5 – PCIF2: Pin Change Interrupt Flag 2 This bit is set when a logic change on any PCINT[17:12] pin has triggered an interrupt request. Provided that the Ibit in SREG and the PCIE2 bit in GIMSK are set, the MCU will jump to the corresponding interrupt vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. • Bit 4 – PCIF1: Pin Change Interrupt Flag 1 This bit is set when a logic change on any PCINT[11:8] pin has triggered an interrupt request. Provided that the Ibit in SREG and the PCIE1 bit in GIMSK are set, the MCU will jump to the corresponding interrupt vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. • Bit 3 – PCIF0: Pin Change Interrupt Flag 0 This bit is set when a logic change on any PCINT[7:0] pin has triggered an interrupt request. Provided that the I-bit in SREG and the PCIE0 bit in GIMSK are set, the MCU will jump to the corresponding interrupt vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. 9.3.4 PCMSK2 – Pin Change Mask Register 2 • Bits 7:6 – Res: Reserved Bits These bits are reserved and will always read zero. Bit 7 6 5 4 3 2 1 0 0x3B (0x5B) – INTF0 PCIF2 PCIF1 PCIF0 – – – GIFR Read/Write R R/W R/W R/W R/W R R R Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x29 (0x49) – – PCINT17 PCINT16 PCINT15 PCINT14 PCINT13 PCINT12 PCMSK2 Read/Write R R R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny1634 [DATASHEET] 53 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 • Bits 5:0 – PCINT[17:12]: Pin Change Enable Mask 17:12 Each PCINTn bit selects if the pin change interrupt of the corresponding I/O pin is enabled. Pin change interrupt on a pin is enabled by setting the mask bit for the pin (PCINTn) and the corresponding group bit (PCIEn) in GIMSK. When this bit is cleared the pin change interrupt on the corresponding pin is disabled. 9.3.5 PCMSK1 – Pin Change Mask Register 1 • Bits 7:4 – Res: Reserved Bits These bits are reserved and will always read zero. • Bits 3:0 – PCINT[11:8]: Pin Change Enable Mask 11:8 Each PCINTn bit selects if the pin change interrupt of the corresponding I/O pin is enabled. Pin change interrupt on a pin is enabled by setting the mask bit for the pin (PCINTn) and the corresponding group bit (PCIEn) in GIMSK. When this bit is cleared the pin change interrupt on the corresponding pin is disabled. 9.3.6 PCMSK0 – Pin Change Mask Register 0 • Bits 7:0 – PCINT[7:0]: Pin Change Enable Mask 7:0 Each PCINTn bit selects if the pin change interrupt of the corresponding I/O pin is enabled. Pin change interrupt on a pin is enabled by setting the mask bit for the pin (PCINTn) and the corresponding group bit (PCIEn) in GIMSK. When this bit is cleared the pin change interrupt on the corresponding pin is disabled. Bit 7 6 5 4 3 2 1 0 0x28 (0x48) – – – – PCINT11 PCINT10 PCINT9 PCINT8 PCMSK1 Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x27 (0x47) PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 PCMSK0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny1634 [DATASHEET] 54 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 10. I/O Ports 10.1 Overview All AVR ports have true Read-Modify-Write functionality when used as general digital I/O ports. This means that the direction of one port pin can be changed without unintentionally changing the direction of any other pin with the SBI and CBI instructions. The same applies when changing drive value (if configured as output) or enabling/disabling of pull-up resistors (if configured as input). Most output buffers have symmetrical drive characteristics with both high sink and source capability, while some are asymmetrical and have high sink and standard source capability. The pin driver is strong enough to drive LED displays directly. All port pins have individually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O pins have protection diodes to both VCC and Ground as indicated in Figure 10-1 on page 54. See “Electrical Characteristics” on page 228 for a complete list of parameters. Figure 10-1. I/O Pin Equivalent Schematic All registers and bit references in this section are written in general form. A lower case “x” represents the numbering letter for the port, and a lower case “n” represents the bit number. However, when using the register or bit defines in a program, the precise form must be used. For example, PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O Registers and bit locations are listed in “” on page 70. Four I/O memory address locations are allocated for each port, one each for the Data Register – PORTx, Data Direction Register – DDRx, Pull-up Enable Register – PUEx, and the Port Input Pins – PINx. The Port Input Pins I/O location is read only, while the Data Register, the Data Direction Register, and the Pull-Up Enable Register are read/write. However, writing a logic one to a bit in the PINx Register, will result in a toggle in the corresponding bit in the Data Register. Using the I/O port as General Digital I/O is described in “Ports as General Digital I/O” on page 54. Most port pins are multiplexed with alternate functions for the peripheral features on the device. How each alternate function interferes with the port pin is described in “Alternate Port Functions” on page 59. Refer to the individual module sections for a full description of the alternate functions. Note that enabling the alternate function of some of the port pins does not affect the use of the other pins in the port as general digital I/O. 10.2 Ports as General Digital I/O The ports are bi-directional I/O ports with optional internal pull-ups. Figure 10-2 shows a functional description of one I/O-port pin, here generically called Pxn. Cpin Logic Rpu See Figure "General Digital I/O" for Details PxnATtiny1634 [DATASHEET] 55 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 10-2. General Digital I/O(1) Note: 1. WEx, WRx, WPx, WDx, REx, RRx, RPx, and RDx are common to all pins within the same port. clkI/O, and SLEEP are common to all ports. 10.2.1 Configuring the Pin Each port pin consists of four register bits: DDxn, PORTxn, PUExn, and PINxn. As shown in “Register Description” on page 71, the DDxn bits are accessed at the DDRx I/O address, the PORTxn bits at the PORTx I/O address, the PUExn bits at the PUEx I/O address, and the PINxn bits at the PINx I/O address. The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written logic one, Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is configured as an input pin. If PORTxn is written logic one when the pin is configured as an output pin, the port pin is driven high (one). If PORTxn is written logic zero when the pin is configured as an output pin, the port pin is driven low (zero). clk RPx RRx RDx WDx SYNCHRONIZER clkI/O: I/O CLOCK D L Q Q RESET RESET Q D Q Q Q D CLR PORTxn Q Q D CLR DDxn PINxn DATA BUS SLEEP SLEEP: SLEEP CONTROL Pxn I/O WPx 0 1 WRx WEx REx RESET Q Q D CLR PUExn WDx: WRITE DDRx WRx: WRITE PORTx RRx: READ PORTx REGISTER RPx: READ PORTx PIN RDx: READ DDRx WEx: WRITE PUEx REx: READ PUEx WPx: WRITE PINx REGISTERATtiny1634 [DATASHEET] 56 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 The pull-up resistor is activated, if the PUExn is written logic one. To switch the pull-up resistor off, PUExn has to be written logic zero. Table 10-1 summarizes the control signals for the pin value. Port pins are tri-stated when a reset condition becomes active, even when no clocks are running. 10.2.2 Toggling the Pin Writing a logic one to PINxn toggles the value of PORTxn, independent on the value of DDRxn. Note that the SBI instruction can be used to toggle one single bit in a port. 10.2.3 Break-Before-Make Switching In Break-Before-Make mode, switching the DDRxn bit from input to output introduces an immediate tri-state period lasting one system clock cycle, as indicated in Figure 10-3. For example, if the system clock is 4MHz and the DDRxn is written to make an output, an immediate tri-state period of 250 ns is introduced before the value of PORTxn is seen on the port pin. To avoid glitches it is recommended that the maximum DDRxn toggle frequency is two system clock cycles. The Break-Before-Make mode applies to the entire port and it is activated by the BBMx bit. For more details, see “PORTCR – Port Control Register” on page 71. When switching the DDRxn bit from output to input no immediate tri-state period is introduced. Table 10-1. Port Pin Configurations DDxn PORTxn PUExn I/O Pull-up Comment 0 X 0 Input No Tri-state (hi-Z) 0 X 1 Input Yes Sources current if pulled low externally 1 0 0 Output No Output low (sink) 1 0 1 Output Yes NOT RECOMMENDED. Output low (sink) and internal pull-up active. Sources current through the internal pull-up resistor and consumes power constantly 1 1 0 Output No Output high (source) 1 1 1 Output Yes Output high (source) and internal pull-up activeATtiny1634 [DATASHEET] 57 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 10-3. Switching Between Input and Output in Break-Before-Make-Mode 10.2.4 Reading the Pin Value Independent of the setting of Data Direction bit DDxn, the port pin can be read through the PINxn Register bit. As shown in Figure 10-2 on page 55, the PINxn Register bit and the preceding latch constitute a synchronizer. This is needed to avoid metastability if the physical pin changes value near the edge of the internal clock, but it also introduces a delay. Figure 10-4 shows a timing diagram of the synchronization when reading an externally applied pin value. The maximum and minimum propagation delays are denoted tpd,max and tpd,min respectively. Figure 10-4. Synchronization when Reading an Externally Applied Pin value Consider the clock period starting shortly after the first falling edge of the system clock. The latch is closed when the clock is low, and goes transparent when the clock is high, as indicated by the shaded region of the “SYNC LATCH” signal. The signal value is latched when the system clock goes low. It is clocked into the PINxn Register at the succeeding positive clock edge. As indicated by the two arrows tpd,max and tpd,min, a single signal transition on the pin will be delayed between ½ and 1½ system clock period depending upon the time of assertion. When reading back a software assigned pin value, a nop instruction must be inserted as indicated in Figure 10-5 on page 58. The out instruction sets the “SYNC LATCH” signal at the positive edge of the clock. In this case, the delay tpd through the synchronizer is one system clock period. out DDRx, r16 nop 0x02 0x01 SYSTEM CLK INSTRUCTIONS DDRx intermediate tri-state cycle out DDRx, r17 PORTx 0x55 0x01 intermediate tri-state cycle Px0 Px1 tri-state tri-state tri-state r17 0x01 r16 0x02 XXX in r17, PINx 0x00 0xFF INSTRUCTIONS SYNC LATCH PINxn r17 XXX SYSTEM CLK tpd, max tpd, minATtiny1634 [DATASHEET] 58 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 10-5. Synchronization when Reading a Software Assigned Pin Value 10.2.5 Digital Input Enable and Sleep Modes As shown in Figure 10-2 on page 55, the digital input signal can be clamped to ground at the input of the schmitttrigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep Controller in Power-down and Standby modes to avoid high power consumption if some input signals are left floating, or have an analog signal level close to VCC/2. SLEEP is overridden for port pins enabled as external interrupt pins. If the external interrupt request is not enabled, SLEEP is active also for these pins. SLEEP is also overridden by various other alternate functions as described in “Alternate Port Functions” on page 59. If a logic high level (“one”) is present on an asynchronous external interrupt pin configured as “Interrupt on Rising Edge, Falling Edge, or Any Logic Change on Pin” while the external interrupt is not enabled, the corresponding External Interrupt Flag will be set when resuming from the above mentioned Sleep mode, as the clamping in these sleep mode produces the requested logic change. 10.2.6 Unconnected Pins If some pins are unused, it is recommended to ensure that these pins have a defined level. Even though most of the digital inputs are disabled in the deep sleep modes as described above, floating inputs should be avoided to reduce current consumption in all other modes where the digital inputs are enabled (Reset, Active mode and Idle mode). The simplest method to ensure a defined level of an unused pin, is to enable the internal pull-up. In this case, the pull-up will be disabled during reset. If low power consumption during reset is important, it is recommended to use an external pull-up or pulldown. Connecting unused pins directly to VCC or GND is not recommended, since this may cause excessive currents if the pin is accidentally configured as an output. out PORTx, r16 nop in r17, PINx 0xFF 0x00 0xFF SYSTEM CLK r16 INSTRUCTIONS SYNC LATCH PINxn r17 t pdATtiny1634 [DATASHEET] 59 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 10.2.7 Program Examples The following code example shows how to set port A pins 0 and 1 high, 2 and 3 low, and define the port pins from 4 to 5 as input with a pull-up assigned to port pin 4. The resulting pin values are read back again, but as previously discussed, a nop instruction is included to be able to read back the value recently assigned to some of the pins. Note: Two temporary registers are used to minimize the time from pull-ups are set on pins 0, 1 and 4, until the direction bits are correctly set, defining bit 2 and 3 as low and redefining bits 0 and 1 as strong high drivers. Note: See “Code Examples” on page 6. 10.3 Alternate Port Functions Most port pins have alternate functions in addition to being general digital I/Os. In Figure 10-6 below is shown how the port pin control signals from the simplified Figure 10-2 on page 55 can be overridden by alternate functions. Assembly Code Example ... ; Define pull-ups and set outputs high ; Define directions for port pins ldi r16,(1<>8); UBRRnL = (unsigned char)baud; /* Enable receiver and transmitter */ UCSRnB = (1<> 1) & 0x01; return ((resh << 8) | resl); }ATtiny1634 [DATASHEET] 157 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 16.8.3 Receive Compete Flag and Interrupt The USART receiver has one flag that indicates the receiver state. The Receive Complete flag (RXCn) indicates if there are unread data present in the receive buffer. This flag is set when unread data exist in the receive buffer, and cleared when the receive buffer is empty (i.e., it does not contain any unread data). If the receiver is disabled (RXENn = 0), the receive buffer will be flushed and, consequently, the RXCn bit will become zero. When the Receive Complete Interrupt Enable (RXCIEn) is set, the USART Receive Complete interrupt will be executed as long as the RXCn flag is set (and provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDRn in order to clear the RXCn flag, otherwise a new interrupt will occur once the interrupt routine terminates. 16.8.4 Receiver Error Flags The USART Receiver has three Error Flags: Frame Error (FEn), Data OverRun (DORn) and Parity Error (UPEn). All can be accessed by reading UCSRnA. Common for the Error Flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the Error Flags, the UCSRnA must be read before the receive buffer (UDRn), since reading the UDRn I/O location changes the buffer read location. Another equality for the Error Flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRnA is written for upward compatibility of future USART implementations. None of the Error Flags can generate interrupts. The Frame Error (FEn) Flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FEn Flag is zero when the stop bit was correctly read (as one), and the FEn Flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FEn Flag is not affected by the setting of the USBSn bit in UCSRnC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. The Data OverRun (DORn) Flag indicates data loss due to a receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DORn Flag is set there was one or more serial frame lost between the frame last read from UDRn, and the next frame read from UDRn. For compatibility with future devices, always write this bit to zero when writing to UCSRnA. The DORn Flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (UPEn) Flag indicates that the next frame in the receive buffer had a Parity Error when received. If Parity Check is not enabled the UPEn bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. For more details see “Parity Bit Calculation” on page 150 and “Parity Checker” on page 157. 16.8.5 Parity Checker The parity checker is active when the high USART Parity Mode bit (UPMn1) is set. The type of parity check to be performed (odd or even) is selected by the UPMn0 bit. When enabled, the parity checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error flag (UPEn) can then be read by software to check if the frame had a parity error. If parity checking is enabled, the UPEn bit is set if the next character that can be read from the receive buffer had a parity error when received. This bit is valid until the receive buffer (UDRn) is read.ATtiny1634 [DATASHEET] 158 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 16.8.6 Disabling the Receiver Unlike the transmitter, the receiver is disabled immediately and any data from ongoing receptions will be lost. When disabled (RXENn = 0), the receiver will no longer override the normal function of the RxDn port pin and the FIFO buffer is flushed, with any remaining data in the buffer lost. 16.8.7 Flushing the Receive Buffer The receiver buffer FIFO will be flushed when the receiver is disabled, i.e., the buffer will be emptied of its contents. Unread data will be lost. To flush the buffer during normal operation, due to for instance an error condition, read the UDRn until the RXCn flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See “Code Examples” on page 6. 16.9 Asynchronous Data Reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxDn pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. 16.9.1 Asynchronous Clock Recovery The clock recovery logic synchronizes the internal clock to the incoming serial frames. Figure 16-5 illustrates the sampling process of the start bit of an incoming frame. In normal mode the sample rate is 16 times the baud rate, in double speed mode eight times. The horizontal arrows illustrate the synchronization variation due to the sampling process. Note the larger time variation when using the double speed mode of operation (U2Xn = 1). Samples denoted zero are samples done when the RxDn line is idle (i.e., no communication activity). Assembly Code Example(1) USART_Flush: sbis UCSRnA, RXCn ret in r16, UDRn rjmp USART_Flush C Code Example(1) void USART_Flush( void ) { unsigned char dummy; while ( UCSRnA & (1< max(16fSCL, 250kHz) 0 400 kHz tHD:STA Hold time (repeated) START Condition 0.6 – µs tLOW Low period of SCL clock 1.3 – µs tHIGH High period of SCL clock 0.6 – µs tSU:STA Set-up time for repeated START condition 0.6 – µs tHD:DAT Data hold time 0 0.9 µs tSU:DAT Data setup time 100 – ns tSU:STO Setup time for STOP condition 0.6 – µs tBUF Bus free time between STOP and START condition 1.3 – µs t SU:STA t LOW t HIGH t LOW t OF t HD:STA t HD:DAT t SU:DAT t SU:STO t BUF SCL SDA t RATtiny1634 [DATASHEET] 234 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 24.7 Analog to Digital Converter Table 24-9. ADC Characteristics, Single Ended Channels. T = -40C to +85C Symbol Parameter Condition Min Typ Max Units Resolution 10 Bits Absolute accuracy (Including INL, DNL, and Quantization, Gain and Offset Errors) VREF = 4V, VCC = 4V, ADC clock = 200kHz 2.0 LSB VREF = 4V, VCC = 4V, ADC clock = 1MHz 2.5 LSB VREF = 4V, VCC = 4V, ADC clock = 200kHz Noise Reduction Mode 1.5 LSB VREF = 4V, VCC = 4V, ADC clock = 1MHz Noise Reduction Mode 2.0 LSB Integral Non-Linearity (INL) (Accuracy after Offset and Gain Calibration) VREF = 4V, VCC = 4V, ADC clock = 200kHz 1.0 LSB Differential Non-linearity (DNL) VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.5 LSB Gain Error VREF = 4V, VCC = 4V, ADC clock = 200kHz 2.0 LSB Offset Error (Absolute) VREF = 4V, VCC = 4V, ADC clock = 200kHz 1.5 LSB Conversion Time Free Running Conversion 14 280 µs Clock Frequency 50 1000 kHz VIN Input Voltage GND VREF V Input Bandwidth 38.5 kHz AREF External Voltage Reference 2.0 VCC V VINT Internal Voltage Reference 1.0 1.1 1.2 V RREF Reference Input Resistance 32 k RAIN Analog Input Resistance 100 M ADC Conversion Output 0 1023 LSBATtiny1634 [DATASHEET] 235 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 24.8 Analog Comparator 24.9 Temperature Sensor Note: 1. Firmware calculates temperature based on factory calibration value. 2. Min and max values are not guaranteed. Contact your local Atmel sales office if higher accuracy is required. 24.10 Parallel Programming Figure 24-4. Parallel Programming Timing, Including some General Timing Requirements Table 24-10. Analog Comparator Characteristics, TA = -40C to +85C Symbol Parameter Condition Min Typ Max Units VAIO Input Offset Voltage VCC = 5V, VIN = VCC / 2 < 10 40 mV ILAC Input Leakage Current VCC = 5V, VIN = VCC / 2 -50 50 nA tAPD Analog Propagation Delay (from saturation to slight overdrive) VCC = 2.7V 750 ns VCC = 4.0V 500 Analog Propagation Delay (large step change) VCC = 2.7V 100 VCC = 4.0V 75 tDPD Digital Propagation Delay VCC = 1.8 - 5.5V 1 2 CLK Table 24-11. Accuracy of Temperature Sensor at Factory Calibration Symbol Parameter Condition Min Typ Max Units ATS Accuracy VCC = 4.0, TA = 25C – 85C 10 C Data & Contol (DATA, XA0/1, BS1, BS2) CLKI t XHXL t WLWH t DVXH t XLDX t PLWL t WLRH WR RDY/BSY PAGEL t PHPL t t BVPH PLBX t XLWL t WLBX tBVWL WLRLATtiny1634 [DATASHEET] 236 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 24-5. Parallel Programming Timing, Loading Sequence with Timing Requirements(1) Note: 1. The timing requirements shown in Figure 24-4 (i.e., tDVXH, tXHXL, and tXLDX) also apply to loading operation. Figure 24-6. Parallel Programming Timing, Reading Sequence (within the Same Page) with Timing Requirements(1) Note: 1. The timing requirements shown in Figure 24-4 (i.e., tDVXH, tXHXL, and tXLDX) also apply to reading operation. CLKI PAGEL t XLXH PLXH t t XLPH z DATA ADDR0 (Low Byte) DATA (Low Byte) DATA (High Byte) ADDR1 (Low Byte) BS1 XA0 XA1 LOAD ADDRESS (LOW BYTE) LOAD DATA (LOW BYTE) LOAD DATA (HIGH BYTE) LOAD DATA LOAD ADDRESS (LOW BYTE) CLKI OE DATA ADDR0 (Low Byte) DATA (Low Byte) DATA (High Byte) ADDR1 (Low Byte) BS1 XA0 XA1 LOAD ADDRESS (LOW BYTE) READ DATA (LOW BYTE) READ DATA (HIGH BYTE) LOAD ADDRESS (LOW BYTE) t BVDV t OLDV t XLOL t OHDZATtiny1634 [DATASHEET] 237 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Notes: 1. tWLRH is valid for the Write Flash, Write EEPROM, Write Fuse bits and Write Lock bits commands. 2. tWLRH_CE is valid for the Chip Erase command. Table 24-12. Parallel Programming Characteristics, TA = 25C, VCC = 5V Symbol Parameter Min Typ Max Units VPP Programming Enable Voltage 11.5 12.5 V IPP Programming Enable Current 250 A tDVXH Data and Control Valid before CLKI High 67 ns tXLXH CLKI Low to CLKI High 200 ns tXHXL CLKI Pulse Width High 150 ns tXLDX Data and Control Hold after CLKI Low 67 ns tXLWL CLKI Low to WR Low 0 ns tXLPH CLKI Low to PAGEL high 0 ns tPLXH PAGEL low to CLKI high 150 ns tBVPH BS1 Valid before PAGEL High 67 ns tPHPL PAGEL Pulse Width High 150 ns tPLBX BS1 Hold after PAGEL Low 67 ns tWLBX BS2/1 Hold after WR Low 67 ns tPLWL PAGEL Low to WR Low 67 ns tBVWL BS1 Valid to WR Low 67 ns tWLWH WR Pulse Width Low 150 ns tWLRL WR Low to RDY/BSY Low 0 1 s tWLRH WR Low to RDY/BSY High(1) 3.7 4.5 ms tWLRH_CE WR Low to RDY/BSY High for Chip Erase(2) 3.7 9 ms tXLOL CLKI Low to OE Low 0 ns tBVDV BS1 Valid to DATA valid 0 250 ns tOLDV OE Low to DATA Valid 250 ns tOHDZ OE High to DATA Tri-stated 250 nsATtiny1634 [DATASHEET] 238 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 24.11 Serial Programming Figure 24-7. Serial Programming Timing Figure 24-8. Serial Programming Waveform Table 24-13. Serial Programming Characteristics, TA = -40C to +85C Symbol Parameter Min Typ Max Units 1/tCLCL Oscillator Frequency @ VCC = 1.8V - 5.5V 0 1 MHz tCLCL Oscillator Period @ VCC = 1.8V - 5.5V 1000 ns 1/tCLCL Oscillator Frequency @ VCC = 4.5V - 5.5V 0 6 MHz tCLCL Oscillator Period @ VCC = 4.5V - 5.5V 167 ns tSHSL SCK Pulse Width High 2 tCLCL ns tSLSH SCK Pulse Width Low 2 tCLCL ns tOVSH MOSI Setup to SCK High tCLCL ns tSHOX MOSI Hold after SCK High 2 tCLCL ns MOSI MISO SCK t OVSH t SHSL t t SHOX SLSH MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUTATtiny1634 [DATASHEET] 239 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 25. Electrical Characteristics @ 105C 25.1 Absolute Maximum Ratings* 25.2 DC Characteristics Table 25-1. DC Characteristics. TA = -40 to +105C Operating Temperature . . . . . . . . . . . -55C to +125C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature . . . . . . . . . . . . . -65C to +150C Voltage on any Pin except RESET with respect to Ground. . . . . . . . . . -0.5V to VCC+0.5V Voltage on RESET with respect to Ground-0.5V to +13.0V Maximum Operating Voltage . . . . . . . . . . . . . . . . 6.0V DC Current per I/O Pin. . . . . . . . . . . . . . . . . . 40.0 mA DC Current VCC and GND Pins . . . . . . . . . . 200.0 mA Symbol Parameter Condition Min Typ (1) Max Units VIL Input Low Voltage VCC = 1.8 - 2.4V -0.5 0.2VCC (2) V VCC = 2.4 - 5.5V -0.5 0.3VCC (2) V Input Low Voltage, RESET Pin as Reset (4) VCC = 1.8 - 5.5V -0.5 0.2VCC (2) VIH Input High-voltage Except RESET pin VCC = 1.8 - 2.4V 0.7VCC(3) VCC +0.5 V VCC = 2.4 - 5.5V 0.6VCC(3) VCC +0.5 V Input High-voltage RESET pin as Reset (4) VCC = 1.8 - 5.5V 0.9VCC(3) VCC +0.5 V VOL Output Low Voltage(5) Except RESET pin(7) Standard I/O: IOL = 10 mA, VCC = 5V 0.6 V High-sink I/O: IOL = 20 mA, VCC = 5V Standard I/O: IOL = 5 mA, VCC = 3V 0.5 V High-sink I/O: IOL = 10 mA, VCC = 3V VOH Output High-voltage(6) Except RESET pin(7) IOH = -10 mA, VCC = 5V 4.3 V IOH = -5 mA, VCC = 3V 2.5 V ILIL Input Leakage Current I/O Pin VCC = 5.5V, pin low (absolute value) < 0.05 1 (8) µA ILIH Input Leakage Current I/O Pin VCC = 5.5V, pin high (absolute value) < 0.05 1 (8) µAATtiny1634 [DATASHEET] 240 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Notes: 1. Typical values at +25C. 2. “Max” means the highest value where the pin is guaranteed to be read as low. 3. “Min” means the lowest value where the pin is guaranteed to be read as high. 4. Not tested in production. 5. Although each I/O port can sink more than the test conditions (10 mA at VCC = 5V, 5 mA at VCC = 3V) under steady state conditions (non-transient), the sum of all IOL (for all ports) should not exceed 100 mA. If IOL exceeds the test conditions, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 6. Although each I/O port can source more than the test conditions (10 mA at VCC = 5V, 5 mA at VCC = 3V) under steady state conditions (non-transient), the sum of all IOH (for all ports) should not exceed 100 mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 7. The RESET pin must tolerate high voltages when entering and operating in programming modes and, as a consequence, has a weak drive strength as compared to regular I/O pins. See “Output Driver Strength” on page 259. 8. These are test limits, which account for leakage currents of the test environment. Actual device leakage currents are lower. 9. Values are with external clock using methods described in “Minimizing Power Consumption” on page 39. Power Reduction is enabled (PRR = 0xFF) and there is no I/O drive. 10. Bod Disabled. 25.3 Clock Table 25-2. Accuracy of Calibrated 8MHz Oscillator Notes: 1. See device ordering codes on page 280 for alternatives. 2. Accuracy of oscillator frequency at calibration point (fixed temperature and fixed voltage). RPU Pull-up Resistor, I/O Pin VCC = 5.5V, input low 20 50 k Pull-up Resistor, Reset Pin VCC = 5.5V, input low 30 60 k ICC Supply Current, Active Mode (9) f = 1MHz, VCC = 2V 0.23 0.4 mA f = 4MHz, VCC = 3V 1.3 1.7 mA f = 8MHz, VCC = 5V 4.3 6 mA Supply Current, Idle Mode (9) f = 1MHz, VCC = 2V 0.04 0.1 mA f = 4MHz, VCC = 3V 0.26 0.4 mA f = 8MHz, VCC = 5V 1.1 1.7 mA Supply Current, Power-Down Mode(10) WDT enabled, VCC = 3V 1.7 6 µA WDT disabled, VCC = 3V 0.1 4 µA Symbol Parameter Condition Min Typ (1) Max Units Calibration Method Target Frequency VCC Temperature Accuracy Factory Calibration 8.0MHz 2.7 – 4V 25C to +105C ±10% (1) User Calibration Within: 7.3 – 8.1MHz Within: 1.8 – 5.5V Within: -40C to +105C ±1% (2)ATtiny1634 [DATASHEET] 241 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Table 25-3. Accuracy of Calibrated 32kHz Oscillator Table 25-4. External Clock Drive 25.4 System and Reset Table 25-5. Enhanced Power-On Reset Note: 1. Values are guidelines only. 2. Threshold where device is released from reset when voltage is rising. 3. The Power-on Reset will not work unless the supply voltage has been below VPOA. Calibration Method Target Frequency VCC Temperature Accuracy Factory Calibration 32kHz 1.8 – 5.5V -40C to +105C ±30% Symbol Parameter VCC = 1.8 - 5.5V VCC = 2.7 - 5.5V VCC = 4.5 - 5.5V Min. Max. Min. Max. Min. Max. Units 1/tCLCL Clock Frequency 0 2 0 8 0 10 MHz tCLCL Clock Period 500 125 100 ns tCHCX High Time 200 40 20 ns tCLCX Low Time 200 40 20 ns tCLCH Rise Time 2.0 1.6 0.5 s tCHCL Fall Time 2.0 1.6 0.5 s tCLCL Change in period from one clock cycle to next 2 2 2 % Symbol Parameter Min(1) Typ(1) Max(1) Units VPOR Release threshold of power-on reset (2) 1.1 1.4 1.7 V VPOA Activation threshold of power-on reset (3) 0.6 1.3 1.7 V SRON Power-On Slope Rate 0.01 V/msATtiny1634 [DATASHEET] 242 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26. Typical Characteristics The data contained in this section is largely based on simulations and characterization of similar devices in the same process and design methods. Thus, the data should be treated as indications of how the part will behave. The following charts show typical behavior. These figures are not tested during manufacturing. During characterisation devices are operated at frequencies higher than test limits but they are not guaranteed to function properly at frequencies higher than the ordering code indicates. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pullups enabled. Current consumption is a function of several factors such as operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. A sine wave generator with rail-to-rail output is used as clock source but current consumption in Power-Down mode is independent of clock selection. The difference between current consumption in Power-Down mode with Watchdog Timer enabled and Power-Down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. The current drawn from pins with a capacitive load may be estimated (for one pin) as follows: where VCC = operating voltage, CL = load capacitance and fSW = average switching frequency of I/O pin. 26.1 Current Consumption in Active Mode Figure 26-1. Active Supply Current vs. Low Frequency (0.1 - 1.0 MHz) I CP VCC CL   f SW  0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 ICC[mA] Frequency [MHz] 5.5V 5.0V 4.5V 4.0V 3.3V 1.8V 2.7VATtiny1634 [DATASHEET] 243 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-2. Active Supply Current vs. Frequency (1 - 12 MHz) Figure 26-3. Active Supply Current vs. VCC (Internal Oscillator, 8 MHz) 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 ICC [mA] Frequency [MHz] 5.5V 5.0V 4.5V 4.0V 3.3V 2.0V 2.7V 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC[mA] VCC [V] INTERNAL RC OSCILLATOR, 8 MHz 105°C 85°C 25°C -40°C 125°CATtiny1634 [DATASHEET] 244 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-4. Active Supply Current vs. VCC (Internal Oscillator, 1 MHz) Figure 26-5. Active Supply Current vs. VCC (Internal Oscillator, 32kHz) 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC[mA] VCC [V] 105°C 85°C 25°C -40°C 125°C 0 5 10 15 20 25 30 35 40 45 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [µA] VCC[V] 105°C 85°C 25°C -40°C 125°CATtiny1634 [DATASHEET] 245 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.2 Current Consumption in Idle Mode Figure 26-6. Idle Supply Current vs. Low Frequency (0.1 - 1.0 MHz) Figure 26-7. Idle Supply Current vs. Frequency (1 - 12 MHz) 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 ICC[mA] Frequency [MHz] 5.5V 5.0V 4.5V 4.0V 3.3V 1.8V 2.7V 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 1 2 3 4 5 6 7 8 9 10 11 12 ICC[mA] Frequency [MHz] 5.5V 5.0V 4.5V 4.0V 3.3V 1.8V 2.7VATtiny1634 [DATASHEET] 246 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-8. Idle Supply Current vs. VCC (Internal Oscillator, 8 MHz) Figure 26-9. Idle Supply Current vs. VCC (Internal Oscillator, 1 MHz) 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 2 2.25 2.5 2.75 3 3.25 3.5 3.75 4 4.25 4.5 4.75 5 5.25 5.5 ICC [mA] VCC [V] 105°C 85°C 25°C -40°C 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC[mA] VCC [V] 105 °C 85°C 25°C -40°CATtiny1634 [DATASHEET] 247 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-10. Idle Supply Current vs. VCC (Internal Oscillator, 32kHz) 26.3 Current Consumption in Standby Mode Figure 26-11. Standby Supply Current vs. VCC (Watchdog Timer Enabled) 0 5 10 15 20 25 30 35 40 45 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [µA] VCC [V] 105°C 85°C 25°C -40°C 0 0.025 0.05 0.075 0.1 0.125 0.15 0.175 0.2 0.225 0.25 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [mA] VCC [V] 8MHz 32kHzATtiny1634 [DATASHEET] 248 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.4 Current Consumption in Power-down Mode Figure 26-12. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) Figure 26-13. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [µA] VCC [V] 105°C 85°C 25°C -40°C 0 1 2 3 4 5 6 7 8 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [µA] VCC [V] 105°C 85°C 25°C -40°CATtiny1634 [DATASHEET] 249 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.5 Current Consumption in Reset Figure 26-14. Reset Current vs. Frequency (0.1 – 1MHz, Excluding Pull-Up Current) Figure 26-15. Reset Current vs. Frequency (1 – 12MHz, Excluding Pull-Up Current) 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 ICC [mA] Frequency [MHz] 5.5V 5.0V 4.5V 4.0V 3.3V 1.8V 2.7V 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 11 12 ICC [mA] Frequency [MHz] 5.5V 5.0V 4.5V 4.0V 3.3V 1.8V 2.7VATtiny1634 [DATASHEET] 250 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-16. Reset Current vs. VCC (No Clock, excluding Reset Pull-Up Current) 26.6 Current Consumption of Peripheral Units Figure 26-17. Current Consumption of Peripherals at 4MHz 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [mA] VCC [V] 105°C 85°C 25°C -40°C 100 200 300 400 500 600 700 800 900 1000 1100 1.5 2 2.5 3 3.5 4 4.5 5 5.5 ICC [µA] VCC [V] ADC AC T/C1 T/C0ATtiny1634 [DATASHEET] 251 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-18. Watchdog Timer Current vs. VCC Figure 26-19. Brownout Detector Current vs. VCC 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 1.5 2 2.5 3 3.5 4 4.5 5 5.5 105°C 85°C 25°C -40°C ICC [µA] VCC [V] 13 14 15 16 17 18 19 20 21 22 23 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 ICC [µA] VCC [V] 105°C 85°C 25°C -40°CATtiny1634 [DATASHEET] 252 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-20. Sampled Brownout Detector Current vs. VCC Figure 26-21. AREF External Reference Pin Current (VCC = 5V) 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 1.8 2.1 2.4 2.7 3 3.3 3.6 3.9 4.2 4.5 4.8 5.1 ICC [µA] VCC [V] 105°C 85°C 25°C -40°C 40 50 60 70 80 90 100 110 120 130 140 150 1.4 1.8 2.2 2.6 3 3.4 3.8 4.2 4.6 5 AREF pin current [µA] AREF [V] 105°C 85°C 25°C -40°CATtiny1634 [DATASHEET] 253 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.7 Pull-up Resistors Figure 26-22. I/O pin Pull-up Resistor Current vs. Input Voltage (VCC = 1.8V) Figure 26-23. I/O Pin Pull-up Resistor Current vs. input Voltage (VCC = 2.7V) 0 5 10 15 20 25 30 35 40 45 50 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 IOP [µA] 105ºC 85ºC 25ºC -40ºC VOP [V] 0 10 20 30 40 50 60 70 80 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 IOP [µA] VOP [V] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 254 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-24. I/O pin Pull-up Resistor Current vs. Input Voltage (VCC = 5V) Figure 26-25. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 1.8V) 0 20 40 60 80 100 120 140 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 IOP [µA] VOP [V] 105ºC 85ºC 25ºC -40ºC 0 5 10 15 20 25 30 35 40 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 IRESET [µA] VRESET [V] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 255 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-26. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) Figure 26-27. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) 0 6 12 18 24 30 36 42 48 54 60 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 IRESET [µA] VRESET [V] 105ºC 85ºC 25ºC -40ºC 0 10 20 30 40 50 60 70 80 90 100 110 120 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 IRESET [µA] VRESET [V] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 256 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.8 Input Thresholds Figure 26-28. VIH: Input Threshold Voltage vs. VCC (I/O Pin, Read as ‘1’) Figure 26-29. VIL: Input Threshold Voltage vs. VCC (I/O Pin, Read as ‘0’) 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] 105ºC 85ºC 25ºC -40ºC Vthreshold [ V] 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] 105ºC 85ºC 25ºC -40ºC Vthreshold [ V]ATtiny1634 [DATASHEET] 257 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-30. VIH-VIL: Input Hysteresis vs. VCC (I/O Pin) Figure 26-31. VIH: Input Threshold Voltage vs. VCC (Reset Pin as I/O, Read as ‘1’) 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] 105ºC 85ºC 25ºC -40ºC Vthreshold [ V] 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] 105ºC 85ºC -40ºC 25ºC Vthreshold [ V]ATtiny1634 [DATASHEET] 258 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-32. VIL: Input Threshold Voltage vs. VCC (Reset Pin as I/O, Read as ‘0’) Figure 26-33. VIH-VIL: Input Hysteresis vs. VCC (Reset Pin as I/O) 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] Vthreshold [V] 105ºC 85ºC 25ºC -40ºC 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 259 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.9 Output Driver Strength Figure 26-34. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 1.8V) Figure 26-35. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 3V) 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VOH [V] IOH [mA] 105ºC 85ºC 25ºC -40ºC 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 0 1 2 3 4 5 6 7 8 9 10 VOH [V] IOH [mA] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 260 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-36. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 5V) Figure 26-37. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 1.8V) 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 0 2 4 6 8 10 12 14 16 18 20 VOH [V] IOH [mA] 105ºC 85ºC 25ºC -40ºC 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VOL [V] IOL [mA] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 261 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-38. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 3V) Figure 26-39. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 5V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 1 2 3 4 5 6 7 8 9 10 VOL [V] IOL [mA] 105ºC 85ºC 25ºC -40ºC 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 2 4 6 8 10 12 14 16 18 20 VOL [V] IOL [mA] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 262 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-40. VOH: Output Voltage vs. Source Current (Reset Pin as I/O, VCC = 1.8V Figure 26-41. VOH: Output Voltage vs. Source Current (Reset Pin as I/O, VCC = 3V 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 VOH [V] IOH [mA] 105ºC 85ºC 25ºC -40ºC 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 VOH [V] IOH [mA] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 263 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-42. VOH: Output Voltage vs. Source Current (Reset Pin as I/O, VCC = 5V Figure 26-43. VOL: Output Voltage vs. Sink Current (Reset Pin as I/O, VCC = 1.8V) 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 VOH [V] IOH [mA] 105ºC 85ºC 25ºC -40ºC 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 VOL [V] IOL [mA] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 264 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-44. VOL: Output Voltage vs. Sink Current (Reset Pin as I/O, VCC = 3V) Figure 26-45. VOL: Output Voltage vs. Sink Current (Reset Pin as I/O, VCC = 5V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL [V] IOL [mA] 105ºC 85ºC 25ºC -40ºC 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 VOL [V] IOL [mA] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 265 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.10 BOD Figure 26-46. BOD Threshold vs Temperature (BODLEVEL = 4.3V) Figure 26-47. BOD Threshold vs Temperature (BODLEVEL = 2.7V) 4.16 4.18 4.2 4.22 4.24 4.26 4.28 4.3 4.32 4.34 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Rising Vcc Falling Vcc Temperature [°C] VThreshold [ V] 2.62 2.64 2.66 2.68 2.7 2.72 2.74 2.76 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Rising Vcc Falling Vcc Temperature [°C] VThreshold [ V]ATtiny1634 [DATASHEET] 266 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-48. BOD Threshold vs Temperature (BODLEVEL = 1.8V) Figure 26-49. Sampled BOD Threshold vs Temperature (BODLEVEL = 4.3V) 1.75 1.76 1.77 1.78 1.79 1.8 1.81 1.82 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Rising Vcc Falling Vcc Temperature [°C] VThreshold [ V] 4.25 4.26 4.27 4.28 4.29 4.3 4.31 4.32 4.33 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Rising Vcc Falling Vcc Temperature [°C] VThreshold [ V]ATtiny1634 [DATASHEET] 267 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-50. Sampled BOD Threshold vs Temperature (BODLEVEL = 2.7V) Figure 26-51. Sampled BOD Threshold vs Temperature (BODLEVEL = 1.8V) 2.71 2.715 2.72 2.725 2.73 2.735 2.74 2.745 2.75 2.755 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Rising Vcc Falling Vcc Temperature [°C] VThreshold [ V] 1.772 1.774 1.776 1.778 1.78 1.782 1.784 1.786 1.788 1.79 1.792 1.794 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Rising Vcc Falling Vcc Temperature [°C] VThreshold [ V]ATtiny1634 [DATASHEET] 268 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.11 Bandgap Voltage Figure 26-52. Bandgap Voltage vs. Supply Voltage Figure 26-53. Bandgap Voltage vs. Temperature 1.04 1.045 1.05 1.055 1.06 1.065 1.07 1.075 1.08 1.5 2 2.5 3 3.5 4 4.5 5 5.5 Bandgap [V] 105°C 85°C 25°C -40°C VCC [V] 1.042 1.044 1.046 1.048 1.05 1.052 1.054 1.056 1.058 1.06 1.062 1.064 1.066 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Bandgap Voltage [V] 5.5V 3.3V 1.8V Temperature [°C]ATtiny1634 [DATASHEET] 269 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.12 Reset Figure 26-54. VIH: Input Threshold Voltage vs. VCC (Reset Pin, Read as ‘1’) Figure 26-55. VIL: Input Threshold Voltage vs. VCC (Reset Pin, Read as ‘0’) 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] Vthreshold [V] 105ºC 85ºC 25ºC -40ºC 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] Vthreshold [V] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 270 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-56. VIH-VIL: Input Hysteresis vs. VCC (Reset Pin ) Figure 26-57. Minimum Reset Pulse Width vs. VCC -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] VHysteresis [V] 105ºC 85ºC 25ºC -40ºC 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC [V] 105ºC 85ºC 25ºC -40ºC TRST [ns]ATtiny1634 [DATASHEET] 271 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 26.13 Analog Comparator Offset Figure 26-58. Analog Comparator Offset vs. VIN (VCC = 5V) Figure 26-59. Analog Comparator Offset vs. VCC (VIN = 1.1V) 0 10 20 30 40 50 60 70 80 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Offset [mV] VIN [V] 105°C 85°C 25°C -40°C 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 1.5 2 2.5 3 3.5 4 4.5 5 5.5 Offset [mV] VCC [V] 105°C 85°C 25°C -40°CATtiny1634 [DATASHEET] 272 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-60. Analog Comparator Hysteresis vs. VIN (VCC = 5.0V) 26.14 Internal Oscillator Speed Figure 26-61. Calibrated Oscillator Frequency (Nominal = 8MHz) vs. VCC 0 5 10 15 20 25 30 35 40 45 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Hysteresis [mV] VIN [V] 105°C 85°C 25°C -40°C 7.8 7.85 7.9 7.95 8 8.05 8.1 8.15 8.2 8.25 8.3 1.9 2.3 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 FRC [MHz] VCC [V] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 273 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-62. Calibrated Oscillator Frequency (Nominal = 8MHz) vs. Temperature Figure 26-63. Calibrated Oscillator Frequency (Nominal = 8MHz) vs. OSCCAL Value 7.92 7.94 7.96 7.98 8 8.02 8.04 8.06 8.08 8.1 8.12 8.14 8.16 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 FRC [MHz] 5.0V 3.0V Temperature [°C] 0 2 4 6 8 10 12 14 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 FRC [MHz] OSCCAL [X1] 105ºC 85ºC 25ºC -40ºCATtiny1634 [DATASHEET] 274 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-64. Calibrated Oscillator Frequency (Nominal = 1MHz) vs. VCC Figure 26-65. Calibrated Oscillator Frequency (Nominal = 1MHz) vs. Temperature 0.97 0.98 0.99 1 1.01 1.02 1.03 1.04 1.05 1.5 2 2.5 3 3.5 4 4.5 5 5.5 FRC [MHz] VCC [V] 105ºC 85ºC 25ºC -40ºC 0.975 0.98 0.985 0.99 0.995 1.00 1.005 1.01 1.015 1.02 1.025 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 FRC [MHz] 5.0V 1.8V Temperature [°C] 3.0VATtiny1634 [DATASHEET] 275 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Figure 26-66. ULP Oscillator Frequency (Nominal = 32kHz) vs. VCC Figure 26-67. ULP Oscillator Frequency (Nominal = 32kHz) vs. Temperature 28.0 28.5 29.0 29.5 30.0 30.5 31.0 31.5 32.0 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 FRC [kHz] VCC [V] 105ºC 85ºC 25ºC -40ºC 26 27 28 29 30 31 32 33 -45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 FRC [kHz] Temperature [°C]ATtiny1634 [DATASHEET] 276 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 27. Register Summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page(s) (0xFF) Reserved – – – – – – – – (0xFE) Reserved – – – – – – – – (0xFD) Reserved – – – – – – – – (0xFC) Reserved – – – – – – – – (0xFB) Reserved – – – – – – – – (0xFA) Reserved – – – – – – – – (0xF9) Reserved – – – – – – – – ... ... ... ... ... ... ... ... ... ... ... (0x85) Reserved – – – – – – – – (0x84) Reserved – – – – – – – – (0x83) Reserved – – – – – – – – (0x82) Reserved – – – – – – – – (0x81) Reserved – – – – – – – – (0x80) Reserved – – – – – – – – (0x7F) TWSCRA TWSHE – TWDIE TWASIE TWEN TWSIE TWPME TWSME 127 (0x7E) TWSCRB TWAA TWCMD[1:0] 127 (0x7D) TWSSRA TWDIF TWASIF TWCH TWRA TWC TWBE TWDIR TWAS 128 (0x7C) TWSA TWI Slave Address Register 130 (0x7B) TWSAM TWI Slave Address Mask Register 130 (0x7A) TWSD TWI Slave Data Register 130 (0x79) UCSR1A RXC1 TXC1 UDRE1 FE1 DOR1 UPE1 U2X1 MPCM1 167 (0x78) UCSR1B RXCIE1 TXCIE1 UDRIE1 RXEN1 TXEN1 UCSZ12 RXB81 TXB81 168 (0x77) UCSR1C UMSEL11 UMSEL10 UPM11 UPM01 USBS1 UCSZ11 UCSZ10 UCPOL1 169 (0x76) UCSR1D RXSIE1 RXS1 SFDE1 171 (0x75) UBRR1H USART1 Baud Rate Register High Byte 172 (0x74) UBRR1L USART1 Baud Rate Register Low Byte 172 (0x73) UDR1 USART1 I/O Data Register 167 (0x72) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 – – WGM11 WGM10 111 (0x71) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 113 (0x70) TCCR1C FOC1A FOC1B – – – – – – 114 (0x6F) TCNT1H Timer/Counter1 – Counter Register High Byte 114 (0x6E) TCNT1L Timer/Counter1 – Counter Register Low Byte 114 (0x6D) OCR1AH Timer/Counter1 – Compare Register A High Byte 114 (0x6C) OCR1AL Timer/Counter1 – Compare Register A Low Byte 114 (0x6B) OCR1BH Timer/Counter1 – Compare Register B High Byte 115 (0x6A) OCR1BL Timer/Counter1 – Compare Register B Low Byte 115 (0x69) ICR1H Timer/Counter1 – Input Capture Register High Byte 115 (0x68) ICR1L Timer/Counter1 – Input Capture Register Low Byte 115 (0x67) GTCCR TSM – – – – – – PSR10 118 (0x66) OSCCAL1 – – – – – – CAL11 CAL10 33 (0x65) OSCTCAL0B Oscillator Temperature Compensation Register B 33 (0x64) OSCTCAL0A Oscillator Temperature Compensation Register A 33 (0x63) OSCCAL0 CAL07 CAL06 CAL05 CAL04 CAL03 CAL02 CAL01 CAL00 32 (0x62) DIDR2 – – – – – ADC11D ADC10D ADC9D 200 (0x61) DIDR1 – – – – ADC8D ADC7D ADC6D ADC5D 200 (0x60) DIDR0 ADC4D ADC3D ADC2D ADC1D ADC0D AIN1D AIN0D AREFD 184, 200 0x3F (0x5F) SREG I T H S V N Z C 14 0x3E (0x5E) SPH – – – – – SP10 SP9 SP8 13 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 13 0x3C (0x5C) GIMSK – INT0 PCIE2 PCIE1 PCIE0 – – – 51 0x3B (0x5B) GIFR – INTF0 PCIF2 PCIF1 PCIF0 – – – 52 0x3A (0x5A) TIMSK TOIE1 OCIE1A OCIE1B – ICIE1 OCIE0B TOIE0 OCIE0A 88, 115 0x39 (0x59) TIFR TOV1 OCF1A OCF1B – ICF1 OCF0B TOV0 OCF0A 89, 116 0x38 (0x58) QTCSR QTouch Control and Status Register 6 0x37 (0x57) SPMCSR – – RSIG CTPB RFLB PGWRT PGERS SPMEN 207 0x36 (0x56) MCUCR – SM1 SM0 SE – – ISC01 ISC00 37, 51 0x35 (0x55) MCUSR – – – – WDRF BORF EXTRF PORF 44 0x34 (0x54) PRR – PRTWI PRTIM0 PRTIM0 PRUSI PRUSART1 PRUSART0 PRADC 38 0x33 (0x53) CLKPR – – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 31 0x32 (0x52) CLKSR OSCRDY CSTR CKOUT_IO SUT CKSEL3 CKSEL2 CKSEL1 CKSEL0 29 0x31 (0x51) Reserved – – – – – – – – 0x30 (0x50) WDTCSR WDIF WDIE WDP3 – WDE WDP2 WDP1 WDP0 45 0x2F (0x4F) CCP CPU Change Protection Register 13 0x2E (0x4E) DWDR DWDR[7:0] 202 0x2D (0x4D) USIBR USI Buffer Register 144 0x2C (0x4C) USIDR USI Data Register 143ATtiny1634 [DATASHEET] 277 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 Note: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operation the specified bit, and can therefore be used on registers containing such Status Flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only. 0x2B (0x4B) USISR USISIF USIOIF USIPF USIDC USICNT3 USICNT2 USICNT1 USICNT0 142 0x2A (0x4A) USICR USISIE USIOIE USIWM1 USIWM0 USICS1 USICS0 USICLK USITC 140 0x29 (0x49) PCMSK2 – – PCINT17 PCINT16 PCINT15 PCINT14 PCINT13 PCINT12 52 0x28 (0x48) PCMSK1 – – – – PCINT11 PCINT10 PCINT9 PCINT8 53 0x27 (0x47) PCMSK0 PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 53 0x26 (0x46) UCSR0A RXC0 TXC0 UDRE0 FE0 DOR0 UPE0 U2X0 MPCM 167 0x25 (0x45) UCSR0B RXCIE0 TXCIE0 UDRIE0 RXEN0 TXEN0 UCSZ02 RXB80 TXB80 168 0x24 (0x44) UCSR0C UMSEL01 UMSEL00 UPM01 UPM00 USBS0 UCSZ01 UCSZ00 UCPOL0 169 0x23 (0x43) UCSR0D RXCIE0 RXS0 SFDE0 – – – – – 171 0x22 (0x42) UBRR0H – – – – USART0 Baud Rate Register High Byte 172 0x21 (0x41) UBRR0L USART0 Baud Rate Register Low Byte 172 0x20 (0x40) UDR0 USART0 I/O Data Register 167 0x1F (0x3F) EEARH – – – – – – – – 0x1E (0x3E) EEARL EEAR[7:0] 22 0x1D (0x3D) EEDR EEPROM Data Register 22 0x1C (0x3C) EECR – – EEPM1 EEPM0 EERIE EEMPE EEPE EERE 22 0x1B (0x3B) TCCR0A COM0A1 COM0A0 COM0B1 COM0B0 – – WGM01 WGM00 84 0x1A (0x3A) TCCR0B FOC0A FOC0B – – WGM02 CS02 CS01 CS00 86 0x19 (0x39) TCNT0 Timer/Counter0 88 0x18 (0x38) OCR0A Timer/Counter0 – Compare Register A 88 0x17 (0x37) OCR0B Timer/Counter0 – Compare Register B 88 0x16 (0x36) GPIOR2 General Purpose Register 2 23 0x15 (0x35) GPIOR1 General Purpose Register 1 24 0x14 (0x34) GPIOR0 General Purpose Register 0 24 0x13 (0x33) PORTCR – – – – – BBMC BBMB BBMA 71 0x12 (0x32) PUEA PUEA7 PUEA6 PUEA5 PUEA4 PUEA3 PUEA2 PUEA1 PUEA0 71 0x11 (0x31) PORTA PORTA7 PORTA6 PORTA5 PORTA4 PORTA3 PORTA2 PORTA1 PORTA0 71 0x10 (0x30) DDRA DDA7 DDA6 DDA5 DDA4 DDA3 DDA2 DDA1 DDA0 71 0x0F (0x2F) PINA PINA7 PINA6 PINA5 PINA4 PINA3 PINA2 PINA1 PINA0 71 0x0E (0x2E) PUEB – – – – PUEB3 PUEB2 PUEB1 PUEB0 72 0x0D (0x2D) PORTB – – – – PORTB3 PORTB2 PORTB1 PORTB0 72 0x0C (0x2C) DDRB – – – – DDB3 DDB2 DDB1 DDB0 72 0x0B (0x2B) PINB – – – – PINB3 PINB2 PINB1 PINB0 72 0x0A (0x2A) PUEC – – PUEC5 PUEC4 PUEC3 PUEC2 PUEC1 PUEC0 72 0x09 (0x29) PORTC – – PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 72 0x08 (0x28) DDRC – – DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 72 0x07 (0x27) PINC – – PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 72 0x06 (0x26) ACSRA ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 182 0x05 (0x25) ACSRB HSEL HLEV ACLP – ACCE ACME ACIRS1 ACIRS0 183 0x04 (0x24) ADMUX REFS1 REFS0 REFEN ADC0EN MUX3 MUX2 MUX1 MUX0 196 0x03 (0x23) ADCSRA ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 197 0x02 (0x22) ADCSRB VDEN VDPD – – ADLAR ADTS2 ADTS1 ADTS0 199 0x01 (0x21) ADCH ADC Data Register High Byte 198 0x00 (0x20) ADCL ADC Data Register Low Byte 198 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page(s)ATtiny1634 [DATASHEET] 278 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 28. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd  Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd  Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl  Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd  Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd  Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd  Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd  Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl  Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd Rd  Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd  Rd K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd  Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd  Rd  Rr Z,N,V 1 COM Rd One’s Complement Rd  0xFF  Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd  0x00  Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd  Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd  Rd  (0xFF - K) Z,N,V 1 INC Rd Increment Rd  Rd + 1 Z,N,V 1 DEC Rd Decrement Rd  Rd  1 Z,N,V 1 TST Rd Test for Zero or Minus Rd  Rd  Rd Z,N,V 1 CLR Rd Clear Register Rd  Rd  Rd Z,N,V 1 SER Rd Set Register Rd  0xFF None 1 BRANCH INSTRUCTIONS JMP k Direct Jump PC  k None 3 RJMP k Relative Jump PC PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC  Z None 2 CALL k Direct Subroutine PC  k None 4 RCALL k Relative Subroutine Call PC  PC + k + 1 None 3 ICALL Indirect Call to (Z) PC  Z None 3 RET Subroutine Return PC  STACK None 4 RETI Interrupt Return PC  STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd  Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd  Rr  C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd  K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC  PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC  PC + 2 or 3 None 1/2/3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC  PC + 2 or 3 None 1/2/3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC  PC + 2 or 3 None 1/2/3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PCPC+k + 1 None 1/2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PCPC+k + 1 None 1/2 BREQ k Branch if Equal if (Z = 1) then PC  PC + k + 1 None 1/2 BRNE k Branch if Not Equal if (Z = 0) then PC  PC + k + 1 None 1/2 BRCS k Branch if Carry Set if (C = 1) then PC  PC + k + 1 None 1/2 BRCC k Branch if Carry Cleared if (C = 0) then PC  PC + k + 1 None 1/2 BRSH k Branch if Same or Higher if (C = 0) then PC  PC + k + 1 None 1/2 BRLO k Branch if Lower if (C = 1) then PC  PC + k + 1 None 1/2 BRMI k Branch if Minus if (N = 1) then PC  PC + k + 1 None 1/2 BRPL k Branch if Plus if (N = 0) then PC  PC + k + 1 None 1/2 BRGE k Branch if Greater or Equal, Signed if (N  V= 0) then PC  PC + k + 1 None 1/2 BRLT k Branch if Less Than Zero, Signed if (N  V= 1) then PC  PC + k + 1 None 1/2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC  PC + k + 1 None 1/2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC  PC + k + 1 None 1/2 BRTS k Branch if T Flag Set if (T = 1) then PC  PC + k + 1 None 1/2 BRTC k Branch if T Flag Cleared if (T = 0) then PC  PC + k + 1 None 1/2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC  PC + k + 1 None 1/2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC  PC + k + 1 None 1/2 BRIE k Branch if Interrupt Enabled if ( I = 1) then PC  PC + k + 1 None 1/2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC  PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b)  1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b)  0 None 2 LSL Rd Logical Shift Left Rd(n+1)  Rd(n), Rd(0)  0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n)  Rd(n+1), Rd(7)  0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)C,Rd(n+1) Rd(n),CRd(7) Z,C,N,V 1ATtiny1634 [DATASHEET] 279 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 ROR Rd Rotate Right Through Carry Rd(7)C,Rd(n) Rd(n+1),CRd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n)  Rd(n+1), n=0..6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3..0)Rd(7..4),Rd(7..4)Rd(3..0) None 1 BSET s Flag Set SREG(s)  1 SREG(s) 1 BCLR s Flag Clear SREG(s)  0 SREG(s) 1 BST Rr, b Bit Store from Register to T T  Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b)  T None 1 SEC Set Carry C  1 C1 CLC Clear Carry C  0 C 1 SEN Set Negative Flag N  1 N1 CLN Clear Negative Flag N  0 N 1 SEZ Set Zero Flag Z  1 Z1 CLZ Clear Zero Flag Z  0 Z 1 SEI Global Interrupt Enable I  1 I1 CLI Global Interrupt Disable I 0 I 1 SES Set Signed Test Flag S  1 S1 CLS Clear Signed Test Flag S  0 S 1 SEV Set Twos Complement Overflow. V  1 V1 CLV Clear Twos Complement Overflow V  0 V 1 SET Set T in SREG T  1 T1 CLT Clear T in SREG T  0 T 1 SEH Set Half Carry Flag in SREG H  1 H1 CLH Clear Half Carry Flag in SREG H  0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd  Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd  Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd  K None 1 LD Rd, X Load Indirect Rd  (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd  (X), X  X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X  X - 1, Rd  (X) None 2 LD Rd, Y Load Indirect Rd  (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd  (Y), Y  Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y  Y - 1, Rd  (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd  (Y + q) None 2 LD Rd, Z Load Indirect Rd  (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd  (Z), Z  Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z  Z - 1, Rd  (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd  (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd  (k) None 2 ST X, Rr Store Indirect (X) Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) Rr, X  X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X  X - 1, (X)  Rr None 2 ST Y, Rr Store Indirect (Y)  Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y)  Rr, Y  Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y  Y - 1, (Y)  Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q)  Rr None 2 ST Z, Rr Store Indirect (Z)  Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z)  Rr, Z  Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z  Z - 1, (Z)  Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q)  Rr None 2 STS k, Rr Store Direct to SRAM (k)  Rr None 2 LPM Load Program Memory R0  (Z) None 3 LPM Rd, Z Load Program Memory Rd  (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd  (Z), Z  Z+1 None 3 SPM Store Program Memory (z)  R1:R0 None IN Rd, P In Port Rd  P None 1 OUT P, Rr Out Port P  Rr None 1 PUSH Rr Push Register on Stack STACK  Rr None 2 POP Rd Pop Register from Stack Rd  STACK None 2 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/Timer) None 1 BREAK Break For On-chip Debug Only None N/A Mnemonics Operands Description Operation Flags #ClocksATtiny1634 [DATASHEET] 280 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 29. Ordering Information Notes: 1. For speed vs. supply voltage, see section 24.3 “Speed” on page 229. 2. All packages are Pb-free, halide-free and fully green, and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Denotes accuracy of the internal oscillator. See Table 24-2 on page 230. 4. Code indicators: – U: matte tin – R: tape & reel 5. Can also be supplied in wafer form. Contact your local Atmel sales office for ordering information and minimum quantities. 29.1 ATtiny1634 Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Accuracy (3) Ordering Code (4) 12 1.8 – 5.5 Industrial (-40C to +85C)(5) 20M1 ±10% ATtiny1634-MU ±2% ATtiny1634R-MU ±10% ATtiny1634-MUR ±2% ATtiny1634R-MUR 20S2 ±10% ATtiny1634-SU ±2% ATtiny1634R-SU ±10% ATtiny1634-SUR ±2% ATtiny1634R-SUR Extended (-40C to +105C)(5) 20M1 ±10% ATtiny1634-MN ±10% ATtiny1634-MNR Package Type 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No-Lead / Micro Lead Frame Package (QFN/MLF) 20S2 20-lead, 0.300" Wide Body, Plastic Gull Wing Small Outline Package (SOIC)ATtiny1634 [DATASHEET] 281 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 30. Packaging Information 30.1 20M1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. REV. 20M1, 20-pad, 4 x 4 x 0.8 mm Body, Lead Pitch 0.50 mm, 20M1 B 12/02/2014 2.6 mm Exposed Pad, Micro Lead Frame Package (MLF) A 0.70 0.75 0.80 A1 – 0.01 0.05 A2 0.20 REF b 0.18 0.23 0.30 D 4.00 BSC D2 2.45 2.60 2.75 E 4.00 BSC E2 2.45 2.60 2.75 e 0.50 BSC L 0.35 0.40 0.55 SIDE VIEW Pin 1 ID Pin #1 Notch (0.20 R) BOTTOM VIEW TOP VIEW Note: Reference JEDEC Standard MO-220, Fig. 1 (SAW Singulation) WGGD-5. COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE D E e A2 A1 A D2 E2 0.08 C L 1 2 3 b 1 2 3ATtiny1634 [DATASHEET] 282 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 30.2 20S2ATtiny1634 [DATASHEET] 283 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 31. Errata The revision letters in this section refer to the revision of the corresponding ATtiny1634 device. 31.1 ATtiny1634 31.1.1 Rev. C • Port Pin Should Not Be Used As Input When ULP Oscillator Is Disabled 1. Port Pin Should Not Be Used As Input When ULP Oscillator Is Disabled Port pin PB3 is not guaranteed to perform as a reliable input when the Ultra Low Power (ULP) oscillator is not running. In addition, the pin is pulled down internally when ULP oscillator is disabled. Problem Fix / Workaround The ULP oscillator is automatically activated when required. To use PB3 as an input, activate the watchdog timer. The watchdog timer automatically enables the ULP oscillator. 31.1.2 Rev. B • Port Pin Should Not Be Used As Input When ULP Oscillator Is Disabled 1. Port Pin Should Not Be Used As Input When ULP Oscillator Is Disabled Port pin PB3 is not guaranteed to perform as a reliable input when the Ultra Low Power (ULP) oscillator is not running. In addition, the pin is pulled down internally when ULP oscillator is disabled. Problem Fix / Workaround The ULP oscillator is automatically activated when required. To use PB3 as an input, activate the watchdog timer. The watchdog timer automatically enables the ULP oscillator. 31.1.3 Rev. A • Flash / EEPROM Can Not Be Written When Supply Voltage Is Below 2.4V • Port Pin Should Not Be Used As Input When ULP Oscillator Is Disabled 1. Flash / EEPROM Can Not Be Written When Supply Voltage Is Below 2.4V When supply voltage is below 2.4V write operations to Flash and EEPROM may fail. Problem Fix / Workaround Do not write to Flash or EEPROM when supply voltage is below 2.4V. 2. Port Pin Should Not Be Used As Input When ULP Oscillator Is Disabled Port pin PB3 is not guaranteed to perform as a reliable input when the Ultra Low Power (ULP) oscillator is not running. In addition, the pin is pulled down internally when ULP oscillator is disabled. Problem Fix / Workaround The ULP oscillator is automatically activated when required. To use PB3 as an input, activate the watchdog timer. The watchdog timer automatically enables the ULP oscillator.ATtiny1634 [DATASHEET] 284 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 32. Datasheet Revision History 32.1 Rev. 8303H – 02/2014 1. Updated: – Updated the front page. Temperature range changed to -40C to +105C – Table 19-2 on page 195. Added 375 LSB for 105C – “Electrical Characteristics @ 105°C” on page 239 – “Typical Characteristics” on page 242 @ 105C – “Ordering Information” on page 280. Ordering code: ATtiny1634-MNR added 2. Added: – “Errata” “Rev. C” on page 283. 32.2 Rev. 8303G – 11/2013 1. Removed references to Wafer Level Chip Scale Package option. 32.3 Rev. 8303F – 08/2013 1. Updated Bit 2 from the UCSR1C register from “USBSZ11” to “UCSZ11” in “Register Summary” on page 276. 32.4 Rev. 8303E – 01/2013 1. Updated: – Applied the Atmel new brand template that includes new log and new addresses. 32.5 Rev. 8303D – 06/12 1. Updated: – “Ordering Information” on page 280 2. Added: – Wafer Level Chip Scale Package “Errata” on page 283 32.6 Rev. 8303C – 03/12 1. Updated: – “Register Description” on page 167 – “Self-Programming” on page 203 32.7 Rev. 8303B – 03/12 1. Removed Preliminary status. 2. Added: – “Typical Characteristics” on page 242 – “Temperature Sensor” on page 235 – “Rev. B” on page 283 3. Updated: – “Pin Descriptions” on page 3 – “Calibrated Internal 8MHz Oscillator” on page 27 – “OSCTCAL0A – Oscillator Temperature Calibration Register A” on page 33ATtiny1634 [DATASHEET] 285 Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014 – “OSCTCAL0B – Oscillator Temperature Calibration Register B” on page 33 – “TWSCRA – TWI Slave Control Register A” on page 127 – “USART (USART0 & USART1)” on page 145 – “Temperature vs. Sensor Output Voltage (Typical)” on page 195 – “DC Characteristics” on page 228 – “Calibration Accuracy of Internal 32kHz Oscillator” on page 231 – “External Clock Drive Characteristics” on page 231 – “Reset, Brown-out, and Internal Voltage Characteristics” on page 231 – “Analog Comparator Characteristics, TA = -40°C to +85°C” on page 235 – “Parallel Programming Characteristics, TA = 25°C, VCC = 5V” on page 237 – “Serial Programming Characteristics, TA = -40°C to +85°C” on page 238 – “Ordering Information” on page 280 32.8 Rev. 8303A – 11/11 Initial revision.ATtiny1634 [DATASHEET] i Atmel-8303HS-AVR-ATtiny1634-Datasheet_02/2014 Table of Contents Features .....................................................................................................1 1 Pin Configurations ...................................................................................2 1.1 Pin Descriptions .................................................................................................3 2 Overview ...................................................................................................4 3 General Information .................................................................................6 3.1 Resources .........................................................................................................6 3.2 Code Examples .................................................................................................6 3.3 Capacitive Touch Sensing .................................................................................6 3.4 Data Retention ...................................................................................................6 4 CPU Core ...................................................................................................6 4.1 Architectural Overview .......................................................................................7 4.2 ALU – Arithmetic Logic Unit ...............................................................................8 4.3 Status Register ..................................................................................................8 4.4 General Purpose Register File ..........................................................................8 4.5 Stack Pointer ...................................................................................................10 4.6 Instruction Execution Timing ...........................................................................10 4.7 Reset and Interrupt Handling ...........................................................................11 4.8 Register Description ........................................................................................13 5 Memories .................................................................................................15 5.1 Program Memory (Flash) .................................................................................15 5.2 Data Memory (SRAM) and Register Files .......................................................16 5.3 Data Memory (EEPROM) ................................................................................17 5.4 Register Description ........................................................................................22 6 Clock System ..........................................................................................24 6.1 Clock Subsystems ...........................................................................................25 6.2 Clock Sources .................................................................................................26 6.3 System Clock Prescaler ..................................................................................28 6.4 Clock Output Buffer .........................................................................................29 6.5 Register Description ........................................................................................29 7 Power Management and Sleep Modes .................................................34 7.1 Sleep Modes ....................................................................................................34 7.2 Power Reduction Register ...............................................................................36 7.3 Minimizing Power Consumption ......................................................................36ATtiny1634 [DATASHEET] ii Atmel-8303HS-AVR-ATtiny1634-Datasheet_02/2014 7.4 Register Description ........................................................................................37 8 System Control and Reset .....................................................................39 8.1 Resetting the AVR ...........................................................................................39 8.2 Reset Sources .................................................................................................39 8.3 Internal Voltage Reference ..............................................................................42 8.4 Watchdog Timer ..............................................................................................43 8.5 Register Description ........................................................................................44 9 Interrupts .................................................................................................47 9.1 Interrupt Vectors ..............................................................................................47 9.2 External Interrupts ...........................................................................................48 9.3 Register Description ........................................................................................51 10 I/O Ports ..................................................................................................54 10.1 Overview ..........................................................................................................54 10.2 Ports as General Digital I/O .............................................................................54 10.3 Alternate Port Functions ..................................................................................59 10.4 Register Description ........................................................................................71 11 8-bit Timer/Counter0 with PWM ............................................................73 11.1 Features ..........................................................................................................73 11.2 Overview ..........................................................................................................73 11.3 Clock Sources .................................................................................................74 11.4 Counter Unit ....................................................................................................74 11.5 Output Compare Unit .......................................................................................75 11.6 Compare Match Output Unit ............................................................................77 11.7 Modes of Operation .........................................................................................78 11.8 Timer/Counter Timing Diagrams ......................................................................82 11.9 Register Description ........................................................................................84 12 16-bit Timer/Counter1 ............................................................................90 12.1 Features ..........................................................................................................90 12.2 Overview ..........................................................................................................90 12.3 Timer/Counter Clock Sources .........................................................................92 12.4 Counter Unit ....................................................................................................92 12.5 Input Capture Unit ...........................................................................................93 12.6 Output Compare Units .....................................................................................95 12.7 Compare Match Output Unit ............................................................................97 12.8 Modes of Operation .........................................................................................98ATtiny1634 [DATASHEET] iii Atmel-8303HS-AVR-ATtiny1634-Datasheet_02/2014 12.9 Timer/Counter Timing Diagrams ....................................................................106 12.10 Accessing 16-bit Registers ............................................................................107 12.11 Register Description ......................................................................................111 13 Timer/Counter Prescaler ......................................................................117 13.1 Prescaler Reset .............................................................................................117 13.2 External Clock Source ...................................................................................118 13.3 Register Description ......................................................................................118 14 I2C Compatible, Two-Wire Slave Interface .........................................119 14.1 Features ........................................................................................................119 14.2 Overview ........................................................................................................119 14.3 General TWI Bus Concepts ...........................................................................119 14.4 TWI Slave Operation .....................................................................................125 14.5 Register Description ......................................................................................127 15 USI – Universal Serial Interface ..........................................................131 15.1 Features ........................................................................................................131 15.2 Overview ........................................................................................................131 15.3 Three-wire Mode ...........................................................................................132 15.4 Two-wire Mode ..............................................................................................134 15.5 Alternative Use ..............................................................................................136 15.6 Program Examples ........................................................................................137 15.7 Register Descriptions ....................................................................................140 16 USART (USART0 & USART1) ..............................................................145 16.1 Features ........................................................................................................145 16.2 USART0 and USART1 ..................................................................................145 16.3 Overview ........................................................................................................145 16.4 Clock Generation ...........................................................................................147 16.5 Frame Formats ..............................................................................................149 16.6 USART Initialization .......................................................................................151 16.7 Data Transmission – The USART Transmitter ..............................................152 16.8 Data Reception – The USART Receiver .......................................................154 16.9 Asynchronous Data Reception ......................................................................158 16.10 Multi-processor Communication Mode ..........................................................162 16.11 Examples of Baud Rate Setting .....................................................................163 16.12 Register Description ......................................................................................167 17 USART in SPI Mode ..............................................................................173ATtiny1634 [DATASHEET] iv Atmel-8303HS-AVR-ATtiny1634-Datasheet_02/2014 17.1 Features ........................................................................................................173 17.2 Overview ........................................................................................................173 17.3 Clock Generation ...........................................................................................173 17.4 SPI Data Modes and Timing ..........................................................................173 17.5 Frame Formats ..............................................................................................174 17.6 Data Transfer .................................................................................................176 17.7 Compatibility with AVR SPI ...........................................................................178 17.8 Register Description ......................................................................................178 18 Analog Comparator ..............................................................................181 18.1 Analog Comparator Multiplexed Input ...........................................................181 18.2 Register Description ......................................................................................182 19 Analog to Digital Converter .................................................................185 19.1 Features ........................................................................................................185 19.2 Overview ........................................................................................................185 19.3 Operation .......................................................................................................186 19.4 Starting a Conversion ....................................................................................187 19.5 Prescaling and Conversion Timing ................................................................188 19.6 Changing Channel or Reference Selection ...................................................191 19.7 ADC Noise Canceler .....................................................................................192 19.8 Analog Input Circuitry ....................................................................................192 19.9 Noise Canceling Techniques .........................................................................193 19.10 ADC Accuracy Definitions .............................................................................193 19.11 ADC Conversion Result .................................................................................195 19.12 Temperature Measurement ...........................................................................195 19.13 Register Description ......................................................................................196 20 debugWIRE On-chip Debug System ...................................................201 20.1 Features ........................................................................................................201 20.2 Overview ........................................................................................................201 20.3 Physical Interface ..........................................................................................201 20.4 Software Break Points ...................................................................................202 20.5 Limitations of debugWIRE .............................................................................202 20.6 Register Description ......................................................................................202 21 Self-Programming ................................................................................203 21.1 Features ........................................................................................................203 21.2 Overview ........................................................................................................203ATtiny1634 [DATASHEET] v Atmel-8303HS-AVR-ATtiny1634-Datasheet_02/2014 21.3 Lock Bits ........................................................................................................203 21.4 Self-Programming the Flash ..........................................................................203 21.5 Preventing Flash Corruption ..........................................................................206 21.6 Programming Time for Flash when Using SPM .............................................206 21.7 Register Description ......................................................................................207 22 Lock Bits, Fuse Bits and Device Signature .......................................208 22.1 Lock Bits ........................................................................................................208 22.2 Fuse Bits ........................................................................................................209 22.3 Device Signature Imprint Table .....................................................................210 22.4 Reading Lock, Fuse and Signature Data from Software ...............................211 23 External Programming .........................................................................214 23.1 Memory Parametrics .....................................................................................214 23.2 Parallel Programming ....................................................................................214 23.3 Serial Programming .......................................................................................223 23.4 Programming Time for Flash and EEPROM ..................................................227 24 Electrical Characteristics ....................................................................228 24.1 Absolute Maximum Ratings* .........................................................................228 24.2 DC Characteristics .........................................................................................228 24.3 Speed ............................................................................................................229 24.4 Clock ..............................................................................................................230 24.5 System and Reset .........................................................................................231 24.6 Two-Wire Serial Interface ..............................................................................233 24.7 Analog to Digital Converter ............................................................................234 24.8 Analog Comparator .......................................................................................235 24.9 Temperature Sensor ......................................................................................235 24.10 Parallel Programming ....................................................................................235 24.11 Serial Programming .......................................................................................238 25 Electrical Characteristics @ 105C .....................................................239 25.1 Absolute Maximum Ratings* .........................................................................239 25.2 DC Characteristics .........................................................................................239 25.3 Clock ..............................................................................................................240 25.4 System and Reset .........................................................................................241 26 Typical Characteristics ........................................................................242 26.1 Current Consumption in Active Mode ............................................................242 26.2 Current Consumption in Idle Mode ................................................................245ATtiny1634 [DATASHEET] vi Atmel-8303HS-AVR-ATtiny1634-Datasheet_02/2014 26.3 Current Consumption in Standby Mode ........................................................247 26.4 Current Consumption in Power-down Mode ..................................................248 26.5 Current Consumption in Reset ......................................................................249 26.6 Current Consumption of Peripheral Units ......................................................250 26.7 Pull-up Resistors ...........................................................................................253 26.8 Input Thresholds ............................................................................................256 26.9 Output Driver Strength ...................................................................................259 26.10 BOD ...............................................................................................................265 26.11 Bandgap Voltage ...........................................................................................268 26.12 Reset .............................................................................................................269 26.13 Analog Comparator Offset .............................................................................271 26.14 Internal Oscillator Speed ...............................................................................272 27 Register Summary ................................................................................276 28 Instruction Set Summary .....................................................................278 29 Ordering Information ...........................................................................280 29.1 ATtiny1634 ....................................................................................................280 30 Packaging Information .........................................................................281 30.1 20M1 ..............................................................................................................281 30.2 20S2 ..............................................................................................................282 31 Errata .....................................................................................................283 31.1 ATtiny1634 ....................................................................................................283 32 Datasheet Revision History .................................................................284 32.1 Rev. 8303H – 02/2014 ...................................................................................284 32.2 Rev. 8303G – 11/2013 ..................................................................................284 32.3 Rev. 8303F – 08/2013 ...................................................................................284 32.4 Rev. 8303E – 01/2013 ...................................................................................284 32.5 Rev. 8303D – 06/12 .......................................................................................284 32.6 Rev. 8303C – 03/12 .......................................................................................284 32.7 Rev. 8303B – 03/12 .......................................................................................284 32.8 Rev. 8303A – 11/11 .......................................................................................285 Table of Contents.......................................................................................iX X X X X X Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com © 2014 Atmel Corporation. / Rev.: Atmel-8303H-AVR-ATtiny1634-Datasheet_02/2014. 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Features • High Performance, Low Power Atmel®AVR® 8-Bit Microcontroller • Advanced RISC Architecture – 130 Powerful Instructions – Most Single Clock Cycle Execution – 32 x 8 General Purpose Working Registers – Fully Static Operation – Up to 16 MIPS Throughput at 16MHz – On-Chip 2-cycle Multiplier • High Endurance Non-volatile Memory Segments – In-System Self-programmable Flash Program Memory • 32KBytes (ATmega329/ATmega3290) • 64KBytes (ATmega649/ATmega6490) – EEPROM • 1Kbytes (ATmega329/ATmega3290) • 2Kbytes (ATmega649/ATmega6490) – Internal SRAM • 2Kbytes (ATmega329/ATmega3290) • 4Kbytes (ATmega649/ATmega6490) – Write/Erase Cycles: 10,000 Flash/ 100,000 EEPROM – Data retention: 20 years at 85°C/100 years at 25°C(1) – Optional Boot Code Section with Independent Lock Bits • In-System Programming by On-chip Boot Program • True Read-While-Write Operation – Programming Lock for Software Security • JTAG (IEEE std. 1149.1 compliant) Interface – Boundary-scan Capabilities According to the JTAG Standard – Extensive On-chip Debug Support – Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface • Peripheral Features – 4 x 25 Segment LCD Driver (ATmega329/ATmega649) – 4 x 40 Segment LCD Driver (ATmega3290/ATmega6490) – Two 8-bit Timer/Counters with Separate Prescaler and Compare Mode – One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode – Real Time Counter with Separate Oscillator – Four PWM Channels – 8-channel, 10-bit ADC – Programmable Serial USART – Master/Slave SPI Serial Interface – Universal Serial Interface with Start Condition Detector – Programmable Watchdog Timer with Separate On-chip Oscillator – On-chip Analog Comparator – Interrupt and Wake-up on Pin Change • Special Microcontroller Features – Power-on Reset and Programmable Brown-out Detection – Internal Calibrated Oscillator – External and Internal Interrupt Sources – Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, and Standby • I/O and Packages – 53/68 Programmable I/O Lines – 64-lead TQFP, 64-pad QFN/MLF, and 100-lead TQFP • Speed Grade: – ATmega329V/ATmega3290V/ATmega649V/ATmega6490V: – 0 - 4MHz @ 1.8 - 5.5V, 0 - 8MHz @ 2.7 - 5.5V – ATmega329/3290/649/6490: – 0 - 8MHz @ 2.7 - 5.5V, 0 - 16MHz @ 4.5 - 5.5V • Temperature range: – -40°C to 85°C Industrial • Ultra-Low Power Consumption – Active Mode: • 1MHz, 1.8V: 350µA • 32kHz, 1.8V: 20µA (including Oscillator) • 32kHz, 1.8V: 40µA (including Oscillator and LCD) – Power-down Mode: • 100nA at 1.8V 8-bit Atmel Microcontroller with In-System Programmable Flash ATmega329/V ATmega3290/V ATmega649/V ATmega6490/V 2552K–AVR–04/112 2552K–AVR–04/11 ATmega329/3290/649/6490 1. Pin Configurations Figure 1-1. Pinout ATmega3290/6490 (OC2A/PCINT15) PB7 DNC (T1/SEG33) PG3 (T0/SEG32) PG4 RESET/PG5 VCC GND (TOSC2) XTAL2 (TOSC1) XTAL1 DNC DNC (PCINT26/SEG31) PJ2 (PCINT27/SEG30) PJ3 (PCINT28/SEG29) PJ4 (PCINT29/SEG28) PJ5 (PCINT30/SEG27) PJ6 DNC (ICP1/SEG26) PD0 (INT0/SEG25) PD1 (SEG24) PD2 (SEG23) PD3 (SEG22) PD4 (SEG21) PD5 (SEG20) PD6 (SEG19) PD7 AVCC AGND AREF PF0 (ADC0) PF1 (ADC1) PF2 (ADC2) PF3 (ADC3) PF4 (ADC4/TCK) PF5 (ADC5/TMS) PF6 (ADC6/TDO) PF7 (ADC7/TDI) DNC DNC PH7 (PCINT23/SEG36) PH6 (PCINT22/SEG37) PH5 (PCINT21/SEG38) PH4 (PCINT20/SEG39) DNC DNC GND VCC DNC PA0 (COM0) PA1 (COM1) PA2 (COM2) PA3 (COM3) PA4 (SEG0) PA5 (SEG1) PA6 (SEG2) PA7 (SEG3) PG2 (SEG4) PC7 (SEG5) PC6 (SEG6) DNC PH3 (PCINT19/SEG7) PH2 (PCINT18/SEG8) PH1 (PCINT17/SEG9) PH0 (PCINT16/SEG10) DNC DNC DNC DNC PC5 (SEG11) PC4 (SEG12) PC3 (SEG13) PC2 (SEG14) PC1 (SEG15) PC0 (SEG16) PG1 (SEG17) PG0 (SEG18) INDEX CORNER ATmega3290/6490 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 LCDCAP (RXD/PCINT0) PE0 (TXD/PCINT1) PE1 (XCK/AIN0/PCINT2) PE2 (AIN1/PCINT3) PE3 (USCK/SCL/PCINT4) PE4 (DI/SDA/PCINT5) PE5 (DO/PCINT6) PE6 (CLKO/PCINT7) PE7 VCC GND DNC (PCINT24/SEG35) PJ0 (PCINT25/SEG34) PJ1 DNC DNC DNC DNC (SS/PCINT8) PB0 (SCK/PCINT9) PB1 (MOSI/PCINT10) PB2 (MISO/PCINT11) PB3 (OC0A/PCINT12) PB4 (OC1A/PCINT13) PB5 (OC1B/PCINT14) PB6 TQFP3 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 1-2. Pinout ATmega329/649 Note: The large center pad underneath the QFN/MLF packages is made of metal and internally connected to GND. It should be soldered or glued to the board to ensure good mechanical stability. If the center pad is left unconnected, the package might loosen from the board. PC0 (SEG12) VCC A GND AREF PF0 (ADC0) PF1 (ADC1) PF2 (ADC2) PF3 (ADC3) PF4 (ADC4/TCK) PF5 (ADC5/TMS) PF6 (ADC6/TDO) PF7 (ADC7/TDI) GND VCC 17 61 60 18 59 20 58 19 21 57 22 56 23 55 24 54 25 53 26 52 27 51 28 29 50 49 30 31 32 (RXD/PCINT0) PE0 (TXD/PCINT1) PE1 LCDCAP (XCK/AIN0/PCINT2) PE2 (AIN1/PCINT3) PE3 (USCK/SCL/PCINT4) PE4 (DI/SDA/PCINT5) PE5 (DO/PCINT6) PE6 (CLKO/PCINT7) PE7 (SCK/PCINT9) PB1 (MOSI/PCINT10) PB2 (MISO/PCINT11) PB3 (OC0A/PCINT12) PB4 (OC2A/PCINT15) PB7 (T1/SEG24) PG3 (OC1B/PCINT14) PB6 (T0/SEG23) PG4 (OC1A/PCINT13) PB5 PC1 (SEG11) PG0 (SEG14) (SEG15) PD7 PC2 (SEG10) PC3 (SEG9) PC4 (SEG8) PC5 (SEG7) PC6 (SEG6) PC7 (SEG5) PA7 (SEG3) PG2 (SEG4) PA6 (SEG2) PA5 (SEG1) PA4 (SEG0) PA3 (COM3) PA0 (COM0) PA1 (COM1) PA2 (COM2) PG1 (SEG13) (SEG19) PD3 (SEG18) PD4 (SEG17) PD5 (SEG16) PD6 (SEG20) PD2 (ICP1/SEG22) PD0 (INT0/SEG21) PD1 (TOSC2) XTAL2 (TOSC1) XTAL1 RESET/PG5 V GND CC INDEX CORNER (SS/PCINT8) PB0 2 3 1 4 5 6 7 8 9 10 11 12 13 14 16 15 64 63 62 47 46 48 45 44 43 42 41 40 39 38 37 36 35 33 34 ATmega329/6494 2552K–AVR–04/11 ATmega329/3290/649/6490 2. Overview The ATmega329/3290/649/6490 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega329/3290/649/6490 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. 2.1 Block Diagram Figure 2-1. Block Diagram PROGRAM COUNTER INTERNAL OSCILLATOR WATCHDOG TIMER STACK POINTER PROGRAM FLASH MCU CONTROL REGISTER SRAM GENERAL PURPOSE REGISTERS INSTRUCTION REGISTER TIMER/ COUNTERS INSTRUCTION DECODER DATA DIR. REG. PORTB DATA DIR. REG. PORTE DATA DIR. REG. PORTA DATA DIR. REG. PORTD DATA REGISTER PORTB DATA REGISTER PORTE DATA REGISTER PORTA DATA REGISTER PORTD TIMING AND CONTROL OSCILLATOR INTERRUPT UNIT EEPROM USART SPI STATUS REGISTER Z Y X ALU PORTE DRIVERS PORTB DRIVERS PORTF DRIVERS PORTA DRIVERS PORTD DRIVERS PORTC DRIVERS PE0 - PE7 PB0 - PB7 PF0 - PF7 PA0 - PA7 GND VCC XTAL1 XTAL2 CONTROL LINES + - ANALOG COMPARATOR PC0 - PC7 8-BIT DATA BUS RESET CALIB. OSC DATA DIR. REG. PORTC DATA REGISTER PORTC ON-CHIP DEBUG JTAG TAP PROGRAMMING LOGIC BOUNDARYSCAN DATA DIR. REG. PORTF DATA REGISTER PORTF ADC PD0 - PD7 DATA DIR. REG. PORTG DATA REG. PORTG PORTG DRIVERS PG0 - PG4 AGND AREF AVCC UNIVERSAL SERIAL INTERFACE AVR CPU LCD CONTROLLER/ DRIVER PORTH DRIVERS PH0 - PH7 DATA DIR. REG. PORTH DATA REGISTER PORTH PORTJ DRIVERS PJ0 - PJ6 DATA DIR. REG. PORTJ DATA REGISTER PORTJ5 2552K–AVR–04/11 ATmega329/3290/649/6490 The Atmel® AVR® core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The Atmel ATmega329/3290/649/6490 provides the following features: 32/64K bytes of In-System Programmable Flash with Read-While-Write capabilities, 1/2K bytes EEPROM, 2/4K byte SRAM, 54/69 general purpose I/O lines, 32 general purpose working registers, a JTAG interface for Boundary-scan, On-chip Debugging support and programming, a complete On-chip LCD controller with internal contrast control, three flexible Timer/Counters with compare modes, internal and external interrupts, a serial programmable USART, Universal Serial Interface with Start Condition Detector, an 8-channel, 10-bit ADC, a programmable Watchdog Timer with internal Oscillator, an SPI serial port, and five software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue functioning. The Power-down mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next interrupt or hardware reset. In Power-save mode, the asynchronous timer and the LCD controller continues to run, allowing the user to maintain a timer base and operate the LCD display while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules except asynchronous timer, LCD controller and ADC, to minimize switching noise during ADC conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low-power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The On-chip In-System re-Programmable (ISP) Flash allows the program memory to be reprogrammed In-System through an SPI serial interface, by a conventional non-volatile memory programmer, or by an On-chip Boot program running on the AVR core. The Boot program can use any interface to download the application program in the Application Flash memory. Software in the Boot Flash section will continue to run while the Application Flash section is updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the Atmel ATmega329/3290/649/6490 is a powerful microcontroller that provides a highly flexible and cost effective solution to many embedded control applications. The Atmel ATmega329/3290/649/6490 is supported with a full suite of program and system development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit Emulators, and Evaluation kits.6 2552K–AVR–04/11 ATmega329/3290/649/6490 2.2 Comparison between ATmega329, ATmega3290, ATmega649 and ATmega6490 The ATmega329, ATmega3290, ATmega649, and ATmega6490 differs only in memory sizes, pin count and pinout. Table 2-1 on page 6 summarizes the different configurations for the four devices. 2.3 Pin Descriptions The following section describes the I/O-pin special functions. 2.3.1 VCC Digital supply voltage. 2.3.2 GND Ground. 2.3.3 Port A (PA7..PA0) Port A is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port A output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port A pins that are externally pulled low will source current if the pull-up resistors are activated. The Port A pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port A also serves the functions of various special features of the ATmega329/3290/649/6490 as listed on page 67. 2.3.4 Port B (PB7..PB0) Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port B has better driving capabilities than the other ports. Port B also serves the functions of various special features of the ATmega329/3290/649/6490 as listed on page 68. Table 2-1. Configuration Summary Device Flash EEPROM RAM LCD Segments General Purpose I/O Pins ATmega329 32Kbytes 1Kbytes 2Kbytes 4 x 25 54 ATmega3290 32Kbytes 1K bytes 2Kbytes 4 x 40 69 ATmega649 64Kbytes 2Kbytes 4Kbytes 4 x 25 54 ATmega6490 64Kbytes 2Kbytes 4Kbytes 4 x 40 697 2552K–AVR–04/11 ATmega329/3290/649/6490 2.3.5 Port C (PC7..PC0) Port C is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port C output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port C also serves the functions of special features of the ATmega329/3290/649/6490 as listed on page 71. 2.3.6 Port D (PD7..PD0) Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port D also serves the functions of various special features of the ATmega329/3290/649/6490 as listed on page 73. 2.3.7 Port E (PE7..PE0) Port E is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port E output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port E pins that are externally pulled low will source current if the pull-up resistors are activated. The Port E pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port E also serves the functions of various special features of the ATmega329/3290/649/6490 as listed on page 75. 2.3.8 Port F (PF7..PF0) Port F serves as the analog inputs to the A/D Converter. Port F also serves as an 8-bit bi-directional I/O port, if the A/D Converter is not used. Port pins can provide internal pull-up resistors (selected for each bit). The Port F output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port F pins that are externally pulled low will source current if the pull-up resistors are activated. The Port F pins are tri-stated when a reset condition becomes active, even if the clock is not running. If the JTAG interface is enabled, the pull-up resistors on pins PF7(TDI), PF5(TMS), and PF4(TCK) will be activated even if a reset occurs. Port F also serves the functions of the JTAG interface.8 2552K–AVR–04/11 ATmega329/3290/649/6490 2.3.9 Port G (PG5..PG0) Port G is a 6-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port G output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port G pins that are externally pulled low will source current if the pull-up resistors are activated. The Port G pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port G also serves the functions of various special features of the ATmega329/3290/649/6490 as listed on page 75. 2.3.10 Port H (PH7..PH0) Port H is a 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port H output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port H pins that are externally pulled low will source current if the pull-up resistors are activated. The Port H pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port H also serves the functions of various special features of the ATmega3290/6490 as listed on page 75. 2.3.11 Port J (PJ6..PJ0) Port J is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port J output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port J pins that are externally pulled low will source current if the pull-up resistors are activated. The Port J pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port J also serves the functions of various special features of the ATmega3290/6490 as listed on page 75. 2.3.12 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running. The minimum pulse length is given in “System and Reset Characteristics” on page 330. Shorter pulses are not guaranteed to generate a reset. 2.3.13 XTAL1 Input to the inverting Oscillator amplifier and input to the internal clock operating circuit. 2.3.14 XTAL2 Output from the inverting Oscillator amplifier. 2.3.15 AVCC AVCC is the supply voltage pin for Port F and the A/D Converter. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. 2.3.16 AREF This is the analog reference pin for the A/D Converter.9 2552K–AVR–04/11 ATmega329/3290/649/6490 2.3.17 LCDCAP An external capacitor (typical > 470nF) must be connected to the LCDCAP pin as shown in Figure 23-2. This capacitor acts as a reservoir for LCD power (VLCD). A large capacitance reduces ripple on VLCD but increases the time until VLCD reaches its target value. 3. Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. Note: 1. 4. Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C. 5. About Code Examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with instructions that allow access to extended I/O. Typically “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”.10 2552K–AVR–04/11 ATmega329/3290/649/6490 6. AVR CPU Core 6.1 Overview This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. 6.2 Architectural Overview Figure 6-1. Block Diagram of the AVR Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is In-System Reprogrammable Flash memory. Flash Program Memory Instruction Register Instruction Decoder Program Counter Control Lines 32 x 8 General Purpose Registrers ALU Status and Control I/O Lines EEPROM Data Bus 8-bit Data SRAM Direct Addressing Indirect Addressing Interrupt Unit SPI Unit Watchdog Timer Analog Comparator I/O Module 2 I/O Module1 I/O Module n11 2552K–AVR–04/11 ATmega329/3290/649/6490 The fast-access Register File contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every program memory address contains a 16- or 32-bit instruction. Program Flash memory space is divided in two sections, the Boot Program section and the Application Program section. Both sections have dedicated Lock bits for write and read/write protection. The SPM instruction that writes into the Application Flash memory section must reside in the Boot Program section. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O Memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. In addition, the ATmega329/3290/649/6490 has Extended I/O space from 0x60 - 0xFF in SRAM where only the ST/STS/STD and LD/LDS/LDD instructions can be used. 6.3 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See the “Instruction Set” section for a detailed description.12 2552K–AVR–04/11 ATmega329/3290/649/6490 6.4 AVR Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software. 6.4.1 SREG – AVR Status Register The AVR Status Register – SREG – is defined as: • Bit 7 – I: Global Interrupt Enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the instruction set reference. • Bit 6 – T: Bit Copy Storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half Carry Flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry Is useful in BCD arithmetic. See the “Instruction Set Description” for detailed information. • Bit 4 – S: Sign Bit, S = N ⊕ V The S-bit is always an exclusive or between the Negative Flag N and the Two’s Complement Overflow Flag V. See the “Instruction Set Description” for detailed information. • Bit 3 – V: Two’s Complement Overflow Flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See the “Instruction Set Description” for detailed information. • Bit 2 – N: Negative Flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 1 – Z: Zero Flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. Bit 7 6 5 4 3 2 1 0 0x3F (0x5F) I T H S V N Z C SREG Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 013 2552K–AVR–04/11 ATmega329/3290/649/6490 • Bit 0 – C: Carry Flag The Carry Flag C indicates a carry in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. 6.5 General Purpose Register File The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 6-2 shows the structure of the 32 general purpose working registers in the CPU. Figure 6-2. AVR CPU General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 6-2, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y- and Z-pointer registers can be set to index any register in the file. 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E Purpose R15 0x0F Working R16 0x10 Registers R17 0x11 … R26 0x1A X-register Low Byte R27 0x1B X-register High Byte R28 0x1C Y-register Low Byte R29 0x1D Y-register High Byte R30 0x1E Z-register Low Byte R31 0x1F Z-register High Byte14 2552K–AVR–04/11 ATmega329/3290/649/6490 6.5.1 The X-register, Y-register, and Z-register The registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 6-3. Figure 6-3. The X-, Y-, and Z-registers In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the instruction set reference for details). 6.6 Stack Pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x60. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when data is popped from the Stack with return from subroutine RET or return from interrupt RETI. The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. 15 XH XL 0 X-register 7 07 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 07 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 70 7 0 R31 (0x1F) R30 (0x1E) Bit 15 14 13 12 11 10 9 8 0x3E (0x5E) SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 SPH 0x3D (0x5D) SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL 76543210 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 0000000015 2552K–AVR–04/11 ATmega329/3290/649/6490 6.7 Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 6-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. Figure 6-4. The Parallel Instruction Fetches and Instruction Executions Figure 6-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 6-5. Single Cycle ALU Operation 6.8 Reset and Interrupt Handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate program vector in the program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. Depending on the Program Counter value, interrupts may be automatically disabled when Boot Lock bits BLB02 or BLB12 are programmed. This feature improves software security. See the section “Memory Programming” on page 293 for details. The lowest addresses in the program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 49. The list also determines the priority levels of the different interrupts. The lower the address the higher is the clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPU Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPU16 2552K–AVR–04/11 ATmega329/3290/649/6490 priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. The Interrupt Vectors can be moved to the start of the Boot Flash section by setting the IVSEL bit in the MCU Control Register (MCUCR). Refer to “Interrupts” on page 49 for more information. The Reset Vector can also be moved to the start of the Boot Flash section by programming the BOOTRST Fuse, see “Boot Loader Support – Read-While-Write Self-Programming” on page 278. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence. Assembly Code Example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMWE ; start EEPROM write sbi EECR, EEWE out SREG, r16 ; restore SREG value (I-bit) C Code Example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ __disable_interrupt(); EECR |= (1< xxx ; .org 0x3802/0x7802 0x3804/0x7804 jmp EXT_INT0 ; IRQ0 Handler 0x3806/0x7806 jmp PCINT0 ; PCINT0 Handler ... ... ... ; 0x1C2C jmp SPM_RDY ; Store Program Memory Ready Handler When the BOOTRST Fuse is programmed and the Boot section size set to 4K bytes, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: Address Labels Code Comments .org 0x0002 0x0002 jmp EXT_INT0 ; IRQ0 Handler 0x002 2 jmp USI_OVF ; USI Overflow Handler 0x002 4 jmp ANA_COMP ; Analog Comparator Handler 0x002 6 jmp ADC ; ADC Conversion Complete Handler 0x002 8 jmp EE_RDY ; EEPROM Ready Handler 0x002 A jmp SPM_RDY ; SPM Ready Handler 0x002 C jmp LCD_SOF ; LCD Start of Frame Handler 0x002 E jmp PCINT2 ; PCINT2 Handler 0x003 0 jmp PCINT3 ; PCINT3 Handler ; 0x003 2 RESET : ldi r16, high(RAMEND) ; Main program start 0x003 3 out SPH,r16 ; Set Stack Pointer to top of RAM 0x003 4 ldi r16, low(RAMEND) 0x003 5 out SPL,r16 0x003 6 sei ; Enable interrupts 0x003 7 xxx ... ... ...52 2552K–AVR–04/11 ATmega329/3290/649/6490 0x0004 jmp PCINT0 ; PCINT0 Handler ... ... ... ; 0x002C jmp SPM_RDY ; Store Program Memory Ready Handler ; .org 0x3800/0x7800 0x3800/0x7801RESET:ldir16,high(RAMEND); Main program start 0x3801/0x7801 out SPH,r16 ; Set Stack Pointer to top of RAM 0x3802/0x7802 ldi r16,low(RAMEND) 0x3803/0x7803 out SPL,r16 0x3804/0x7804 sei ; Enable interrupts 0x3805/0x7805 xxx When the BOOTRST Fuse is programmed, the Boot section size set to 4K bytes and the IVSEL bit in the MCUCR Register is set before any interrupts are enabled, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: Address Labels Code Comments ; .org 0x3800/0x7800 0x3800/0x7800 jmp RESET ; Reset handler 0x3802/0x7802 jmp EXT_INT0 ; IRQ0 Handler 0x3804/0x7804 jmp PCINT0 ; PCINT0 Handler ... ... ... ; 0x382C/0x782C jmp SPM_RDY ; Store Program Memory Ready Handler ; 0x382E/0x782ERESET:ldir16,high(RAMEND); Main program start 0x382F/0x782F out SPH,r16 ; Set Stack Pointer to top of RAM 0x3830/0x7830 ldi r16,low(RAMEND) 0x3831/0x7831 out SPL,r16 0x3832/0x7832 sei ; Enable interrupts 0x3833/0x7833 xxx 11.1.1 Moving Interrupts Between Application and Boot Space The MCU Control Register controls the placement of the Interrupt Vector table. 11.2 Register Description 11.2.1 MCUCR – MCU Control Register • Bit 1 – IVSEL: Interrupt Vector Select When the IVSEL bit is cleared (zero), the Interrupt Vectors are placed at the start of the Flash memory. When this bit is set (one), the Interrupt Vectors are moved to the beginning of the Boot Loader section of the Flash. The actual address of the start of the Boot Flash Section is determined by the BOOTSZ Fuses. Refer to the section “Boot Loader Support – Read-While-Write Bit 7 6 5 4 3 2 1 0 0x35 (0x55) JTD – – PUD – – IVSEL IVCE MCUCR Read/Write R/W R R R/W R R R/W R/W Initial Value 0 0 0 0 0 0 0 053 2552K–AVR–04/11 ATmega329/3290/649/6490 Self-Programming” on page 278 for details. To avoid unintentional changes of Interrupt Vector tables, a special write procedure must be followed to change the IVSEL bit: 1. Write the Interrupt Vector Change Enable (IVCE) bit to one. 2. Within four cycles, write the desired value to IVSEL while writing a zero to IVCE. Interrupts will automatically be disabled while this sequence is executed. Interrupts are disabled in the cycle IVCE is set, and they remain disabled until after the instruction following the write to IVSEL. If IVSEL is not written, interrupts remain disabled for four cycles. The I-bit in the Status Register is unaffected by the automatic disabling. Note: If Interrupt Vectors are placed in the Boot Loader section and Boot Lock bit BLB02 is programmed, interrupts are disabled while executing from the Application section. If Interrupt Vectors are placed in the Application section and Boot Lock bit BLB12 is programed, interrupts are disabled while executing from the Boot Loader section. Refer to the section “Boot Loader Support – Read-WhileWrite Self-Programming” on page 278 for details on Boot Lock bits. • Bit 0 – IVCE: Interrupt Vector Change Enable The IVCE bit must be written to logic one to enable change of the IVSEL bit. IVCE is cleared by hardware four cycles after it is written or when IVSEL is written. Setting the IVCE bit will disable interrupts, as explained in the IVSEL description above. See Code Example below. Assembly Code Example Move_interrupts: ;Get MCUCR in r16, MCUCR mov r17, r16 ; Enable change of Interrupt Vectors ori r16, (1< CSn2:0 > 1). The number of system clock cycles from when the timer is enabled to the first count occurs can be from 1 to N+1 system clock cycles, where N equals the prescaler divisor (8, 64, 256, or 1024). It is possible to use the prescaler reset for synchronizing the Timer/Counter to program execution. However, care must be taken if the other Timer/Counter that shares the same prescaler also uses prescaling. A prescaler reset will affect the prescaler period for all Timer/Counters it is connected to. 15.0.3 External Clock Source An external clock source applied to the T1/T0 pin can be used as Timer/Counter clock (clkT1/clkT0). The T1/T0 pin is sampled once every system clock cycle by the pin synchronization logic. The synchronized (sampled) signal is then passed through the edge detector. Figure 15-1 shows a functional equivalent block diagram of the T1/T0 synchronization and edge detector logic. The registers are clocked at the positive edge of the internal system clock (clkI/O). The latch is transparent in the high period of the internal system clock. The edge detector generates one clkT1/clkT0 pulse for each positive (CSn2:0 = 7) or negative (CSn2:0 = 6) edge it detects. Figure 15-1. T1/T0 Pin Sampling The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles from an edge has been applied to the T1/T0 pin to the counter is updated. Tn_sync (To Clock Select Logic) Synchronization Edge Detector D Q D Q LE Tn D Q clkI/O108 2552K–AVR–04/11 ATmega329/3290/649/6490 Enabling and disabling of the clock input must be done when T1/T0 has been stable for at least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated. Each half period of the external clock applied must be longer than one system clock cycle to ensure correct sampling. The external clock must be guaranteed to have less than half the system clock frequency (fExtClk < fclk_I/O/2) given a 50/50% duty cycle. Since the edge detector uses sampling, the maximum frequency of an external clock it can detect is half the sampling frequency (Nyquist sampling theorem). However, due to variation of the system clock frequency and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is recommended that maximum frequency of an external clock source is less than fclk_I/O/2.5. An external clock source can not be prescaled. Figure 15-2. Prescaler for Timer/Counter0 and Timer/Counter1(1) Note: 1. The synchronization logic on the input pins (T1/T0) is shown in Figure 15-1. 15.1 Register Description 15.1.1 GTCCR – General Timer/Counter Control Register • Bit 7 – TSM: Timer/Counter Synchronization Mode Writing the TSM bit to one activates the Timer/Counter Synchronization mode. In this mode, the value that is written to the PSR2 and PSR10 bits is kept, hence keeping the corresponding prescaler reset signals asserted. This ensures that the corresponding Timer/Counters are halted and can be configured to the same value without the risk of one of them advancing during configuration. When the TSM bit is written to zero, the PSR2 and PSR10 bits are cleared by hardware, and the Timer/Counters start counting simultaneously. • Bit 0 – PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0 PSR10 Clear clkT1 clkT0 T1 T0 clkI/O Synchronization Synchronization Bit 7 6 5 4 3 2 1 0 0x23 (0x43) TSM – – – – – PSR2 PSR10 GTCCR Read/Write R/W R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0109 2552K–AVR–04/11 ATmega329/3290/649/6490 When this bit is one, Timer/Counter1 and Timer/Counter0 prescaler will be Reset. This bit is normally cleared immediately by hardware, except if the TSM bit is set. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler and a reset of this prescaler will affect both timers.110 2552K–AVR–04/11 ATmega329/3290/649/6490 16. 16-bit Timer/Counter1 16.1 Features The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave generation, and signal timing measurement. The main features are: • True 16-bit Design (i.e., Allows 16-bit PWM) • Two independent Output Compare Units • Double Buffered Output Compare Registers • One Input Capture Unit • Input Capture Noise Canceler • Clear Timer on Compare Match (Auto Reload) • Glitch-free, Phase Correct Pulse Width Modulator (PWM) • Variable PWM Period • Frequency Generator • External Event Counter • Four independent interrupt Sources (TOV1, OCF1A, OCF1B, and ICF1) 16.2 Overview Most register and bit references in this section are written in general form. A lower case “n” replaces the Timer/Counter number, and a lower case “x” replaces the Output Compare unit. However, when using the register or bit defines in a program, the precise form must be used, i.e., TCNT1 for accessing Timer/Counter1 counter value and so on. A simplified block diagram of the 16-bit Timer/Counter is shown in Figure 16-1. For the actual placement of I/O pins, refer to “Pinout ATmega3290/6490” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “Register Description” on page 132. The PRTIM1 bit in “Power Reduction Register” on page 37 must be written to zero to enable the Timer/Counter1 module.111 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 16-1. 16-bit Timer/Counter Block Diagram(1) Note: 1. Refer to Figure 1-1 on page 2, Table 13-5 on page 68, and Table 13-11 on page 72 for Timer/Counter1 pin placement and description. 16.2.1 Registers The Timer/Counter (TCNT1), Output Compare Registers (OCR1A/B), and Input Capture Register (ICR1) are all 16-bit registers. Special procedures must be followed when accessing the 16- bit registers. These procedures are described in the section “Accessing 16-bit Registers” on page 113. The Timer/Counter Control Registers (TCCR1A/B) are 8-bit registers and have no CPU access restrictions. Interrupt requests (abbreviated to Int.Req. in the figure) signals are all visible in the Timer Interrupt Flag Register (TIFR1). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK1). TIFR1 and TIMSK1 are not shown in the figure. The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on the T1 pin. The Clock Select logic block controls which clock source and edge the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the Clock Select logic is referred to as the timer clock (clkT1). The double buffered Output Compare Registers (OCR1A/B) are compared with the Timer/Counter value at all time. The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pin (OC1A/B). See “OutClock Select Timer/Counter DATA BUS OCRnA OCRnB ICRn = = TCNTn Waveform Generation Waveform Generation OCnA OCnB Noise Canceler ICPn = Fixed TOP Values Edge Detector Control Logic = 0 TOP BOTTOM Count Clear Direction TOVn (Int.Req.) OCnA (Int.Req.) OCnB (Int.Req.) ICFn (Int.Req.) TCCRnA TCCRnB ( From Analog Comparator Ouput ) Tn Edge Detector ( From Prescaler ) clkTn112 2552K–AVR–04/11 ATmega329/3290/649/6490 put Compare Units” on page 119.. The compare match event will also set the Compare Match Flag (OCF1A/B) which can be used to generate an Output Compare interrupt request. The Input Capture Register can capture the Timer/Counter value at a given external (edge triggered) event on either the Input Capture pin (ICP1) or on the Analog Comparator pins (See “Analog Comparator” on page 207.) The Input Capture unit includes a digital filtering unit (Noise Canceler) for reducing the chance of capturing noise spikes. The TOP value, or maximum Timer/Counter value, can in some modes of operation be defined by either the OCR1A Register, the ICR1 Register, or by a set of fixed values. When using OCR1A as TOP value in a PWM mode, the OCR1A Register can not be used for generating a PWM output. However, the TOP value will in this case be double buffered allowing the TOP value to be changed in run time. If a fixed TOP value is required, the ICR1 Register can be used as an alternative, freeing the OCR1A to be used as PWM output. 16.2.2 Definitions The following definitions are used extensively throughout the section: 16.2.3 Compatibility The 16-bit Timer/Counter has been updated and improved from previous versions of the 16-bit AVR Timer/Counter. This 16-bit Timer/Counter is fully compatible with the earlier version regarding: • All 16-bit Timer/Counter related I/O Register address locations, including Timer Interrupt Registers. • Bit locations inside all 16-bit Timer/Counter Registers, including Timer Interrupt Registers. • Interrupt Vectors. The following control bits have changed name, but have same functionality and register location: • PWM10 is changed to WGM10. • PWM11 is changed to WGM11. • CTC1 is changed to WGM12. The following bits are added to the 16-bit Timer/Counter Control Registers: • FOC1A and FOC1B are added to TCCR1C. • WGM13 is added to TCCR1B. The 16-bit Timer/Counter has improvements that will affect the compatibility in some special cases. Table 16-1. Definitions of Timer/Counter values. BOTTOM The counter reaches the BOTTOM when it becomes 0x0000. MAX The counter reaches its MAXimum when it becomes 0xFFFF (decimal 65535). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be one of the fixed values: 0x00FF, 0x01FF, or 0x03FF, or to the value stored in the OCR1A or ICR1 Register. The assignment is dependent of the mode of operation.113 2552K–AVR–04/11 ATmega329/3290/649/6490 16.3 Accessing 16-bit Registers The TCNT1, OCR1A/B, and ICR1 are 16-bit registers that can be accessed by the AVR CPU via the 8-bit data bus. The 16-bit register must be byte accessed using two read or write operations. Each 16-bit timer has a single 8-bit register for temporary storing of the high byte of the 16-bit access. The same temporary register is shared between all 16-bit registers within each 16-bit timer. Accessing the low byte triggers the 16-bit read or write operation. When the low byte of a 16-bit register is written by the CPU, the high byte stored in the temporary register, and the low byte written are both copied into the 16-bit register in the same clock cycle. When the low byte of a 16-bit register is read by the CPU, the high byte of the 16-bit register is copied into the temporary register in the same clock cycle as the low byte is read. Not all 16-bit accesses uses the temporary register for the high byte. Reading the OCR1A/B 16- bit registers does not involve using the temporary register. To do a 16-bit write, the high byte must be written before the low byte. For a 16-bit read, the low byte must be read before the high byte. The following code examples show how to access the 16-bit Timer Registers assuming that no interrupts updates the temporary register. The same principle can be used directly for accessing the OCR1A/B and ICR1 Registers. Note that when using “C”, the compiler handles the 16-bit access. Note: 1. See “About Code Examples” on page 9. The assembly code example returns the TCNT1 value in the r17:r16 register pair. It is important to notice that accessing 16-bit registers are atomic operations. If an interrupt occurs between the two instructions accessing the 16-bit register, and the interrupt code updates the temporary register by accessing the same or any other of the 16-bit Timer Registers, then the result of the access outside the interrupt will be corrupted. Therefore, when both Assembly Code Examples(1) ... ; Set TCNT1 to 0x01FF ldi r17,0x01 ldi r16,0xFF out TCNT1H,r17 out TCNT1L,r16 ; Read TCNT1 into r17:r16 in r16,TCNT1L in r17,TCNT1H ... C Code Examples(1) unsigned int i; ... /* Set TCNT1 to 0x01FF */ TCNT1 = 0x1FF; /* Read TCNT1 into i */ i = TCNT1; ...114 2552K–AVR–04/11 ATmega329/3290/649/6490 the main code and the interrupt code update the temporary register, the main code must disable the interrupts during the 16-bit access. The following code examples show how to do an atomic read of the TCNT1 Register contents. Reading any of the OCR1A/B or ICR1 Registers can be done by using the same principle. Note: 1. See “About Code Examples” on page 9. The assembly code example returns the TCNT1 value in the r17:r16 register pair. Assembly Code Example(1) TIM16_ReadTCNT1: ; Save global interrupt flag in r18,SREG ; Disable interrupts cli ; Read TCNT1 into r17:r16 in r16,TCNT1L in r17,TCNT1H ; Restore global interrupt flag out SREG,r18 ret C Code Example(1) unsigned int TIM16_ReadTCNT1( void ) { unsigned char sreg; unsigned int i; /* Save global interrupt flag */ sreg = SREG; /* Disable interrupts */ __disable_interrupt(); /* Read TCNT1 into i */ i = TCNT1; /* Restore global interrupt flag */ SREG = sreg; return i; }115 2552K–AVR–04/11 ATmega329/3290/649/6490 The following code examples show how to do an atomic write of the TCNT1 Register contents. Writing any of the OCR1A/B or ICR1 Registers can be done by using the same principle. Note: 1. See “About Code Examples” on page 9. The assembly code example requires that the r17:r16 register pair contains the value to be written to TCNT1. 16.3.1 Reusing the Temporary High Byte Register If writing to more than one 16-bit register where the high byte is the same for all registers written, then the high byte only needs to be written once. However, note that the same rule of atomic operation described previously also applies in this case. Assembly Code Example(1) TIM16_WriteTCNT1: ; Save global interrupt flag in r18,SREG ; Disable interrupts cli ; Set TCNT1 to r17:r16 out TCNT1H,r17 out TCNT1L,r16 ; Restore global interrupt flag out SREG,r18 ret C Code Example(1) void TIM16_WriteTCNT1( unsigned int i ) { unsigned char sreg; unsigned int i; /* Save global interrupt flag */ sreg = SREG; /* Disable interrupts */ __disable_interrupt(); /* Set TCNT1 to i */ TCNT1 = i; /* Restore global interrupt flag */ SREG = sreg; }116 2552K–AVR–04/11 ATmega329/3290/649/6490 16.4 Timer/Counter Clock Sources The Timer/Counter can be clocked by an internal or an external clock source. The clock source is selected by the Clock Select logic which is controlled by the Clock Select (CS12:0) bits located in the Timer/Counter control Register B (TCCR1B). For details on clock sources and prescaler, see “Timer/Counter0 and Timer/Counter1 Prescalers” on page 107. 16.5 Counter Unit The main part of the 16-bit Timer/Counter is the programmable 16-bit bi-directional counter unit. Figure 16-2 shows a block diagram of the counter and its surroundings. Figure 16-2. Counter Unit Block Diagram Signal description (internal signals): Count Increment or decrement TCNT1 by 1. Direction Select between increment and decrement. Clear Clear TCNT1 (set all bits to zero). clkT1 Timer/Counter clock. TOP Signalize that TCNT1 has reached maximum value. BOTTOM Signalize that TCNT1 has reached minimum value (zero). The 16-bit counter is mapped into two 8-bit I/O memory locations: Counter High (TCNT1H) containing the upper eight bits of the counter, and Counter Low (TCNT1L) containing the lower eight bits. The TCNT1H Register can only be indirectly accessed by the CPU. When the CPU does an access to the TCNT1H I/O location, the CPU accesses the high byte temporary register (TEMP). The temporary register is updated with the TCNT1H value when the TCNT1L is read, and TCNT1H is updated with the temporary register value when TCNT1L is written. This allows the CPU to read or write the entire 16-bit counter value within one clock cycle via the 8-bit data bus. It is important to notice that there are special cases of writing to the TCNT1 Register when the counter is counting that will give unpredictable results. The special cases are described in the sections where they are of importance. Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT1). The clkT1 can be generated from an external or internal clock source, selected by the Clock Select bits (CS12:0). When no clock source is selected (CS12:0 = 0) the timer is stopped. However, the TCNT1 value can be accessed by the CPU, independent of TEMP (8-bit) DATA BUS (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) Control Logic Count Clear Direction TOVn (Int.Req.) Clock Select TOP BOTTOM Tn Edge Detector ( From Prescaler ) clkTn117 2552K–AVR–04/11 ATmega329/3290/649/6490 whether clkT1 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the Waveform Generation mode bits (WGM13:0) located in the Timer/Counter Control Registers A and B (TCCR1A and TCCR1B). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare outputs OC1x. For more details about advanced counting sequences and waveform generation, see “Modes of Operation” on page 123. The Timer/Counter Overflow Flag (TOV1) is set according to the mode of operation selected by the WGM13:0 bits. TOV1 can be used for generating a CPU interrupt. 16.6 Input Capture Unit The Timer/Counter incorporates an Input Capture unit that can capture external events and give them a time-stamp indicating time of occurrence. The external signal indicating an event, or multiple events, can be applied via the ICP1 pin or alternatively, via the analog-comparator unit. The time-stamps can then be used to calculate frequency, duty-cycle, and other features of the signal applied. Alternatively the time-stamps can be used for creating a log of the events. The Input Capture unit is illustrated by the block diagram shown in Figure 16-3. The elements of the block diagram that are not directly a part of the Input Capture unit are gray shaded. The small “n” in register and bit names indicates the Timer/Counter number. Figure 16-3. Input Capture Unit Block Diagram When a change of the logic level (an event) occurs on the Input Capture pin (ICP1), alternatively on the Analog Comparator output (ACO), and this change confirms to the setting of the edge detector, a capture will be triggered. When a capture is triggered, the 16-bit value of the counter (TCNT1) is written to the Input Capture Register (ICR1). The Input Capture Flag (ICF1) is set at the same system clock as the TCNT1 value is copied into ICR1 Register. If enabled (ICIE1 = 1), the Input Capture Flag generates an Input Capture interrupt. The ICF1 Flag is automatically ICFn (Int.Req.) Analog Comparator WRITE ICRn (16-bit Register) ICRnH (8-bit) Noise Canceler ICPn Edge Detector TEMP (8-bit) DATA BUS (8-bit) ICRnL (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) ACO* ACIC* ICNC ICES118 2552K–AVR–04/11 ATmega329/3290/649/6490 cleared when the interrupt is executed. Alternatively the ICF1 Flag can be cleared by software by writing a logical one to its I/O bit location. Reading the 16-bit value in the Input Capture Register (ICR1) is done by first reading the low byte (ICR1L) and then the high byte (ICR1H). When the low byte is read the high byte is copied into the high byte temporary register (TEMP). When the CPU reads the ICR1H I/O location it will access the TEMP Register. The ICR1 Register can only be written when using a Waveform Generation mode that utilizes the ICR1 Register for defining the counter’s TOP value. In these cases the Waveform Generation mode (WGM13:0) bits must be set before the TOP value can be written to the ICR1 Register. When writing the ICR1 Register the high byte must be written to the ICR1H I/O location before the low byte is written to ICR1L. For more information on how to access the 16-bit registers refer to “Accessing 16-bit Registers” on page 113. 16.6.1 Input Capture Trigger Source The main trigger source for the Input Capture unit is the Input Capture pin (ICP1). Timer/Counter1 can alternatively use the Analog Comparator output as trigger source for the Input Capture unit. The Analog Comparator is selected as trigger source by setting the Analog Comparator Input Capture (ACIC) bit in the Analog Comparator Control and Status Register (ACSR). Be aware that changing trigger source can trigger a capture. The Input Capture Flag must therefore be cleared after the change. Both the Input Capture pin (ICP1) and the Analog Comparator output (ACO) inputs are sampled using the same technique as for the T1 pin (Figure 15-1 on page 107). The edge detector is also identical. However, when the noise canceler is enabled, additional logic is inserted before the edge detector, which increases the delay by four system clock cycles. Note that the input of the noise canceler and edge detector is always enabled unless the Timer/Counter is set in a Waveform Generation mode that uses ICR1 to define TOP. An Input Capture can be triggered by software by controlling the port of the ICP1 pin. 16.6.2 Noise Canceler The noise canceler improves noise immunity by using a simple digital filtering scheme. The noise canceler input is monitored over four samples, and all four must be equal for changing the output that in turn is used by the edge detector. The noise canceler is enabled by setting the Input Capture Noise Canceler (ICNC1) bit in Timer/Counter Control Register B (TCCR1B). When enabled the noise canceler introduces additional four system clock cycles of delay from a change applied to the input, to the update of the ICR1 Register. The noise canceler uses the system clock and is therefore not affected by the prescaler. 16.6.3 Using the Input Capture Unit The main challenge when using the Input Capture unit is to assign enough processor capacity for handling the incoming events. The time between two events is critical. If the processor has not read the captured value in the ICR1 Register before the next event occurs, the ICR1 will be overwritten with a new value. In this case the result of the capture will be incorrect. When using the Input Capture interrupt, the ICR1 Register should be read as early in the interrupt handler routine as possible. Even though the Input Capture interrupt has relatively high119 2552K–AVR–04/11 ATmega329/3290/649/6490 priority, the maximum interrupt response time is dependent on the maximum number of clock cycles it takes to handle any of the other interrupt requests. Using the Input Capture unit in any mode of operation when the TOP value (resolution) is actively changed during operation, is not recommended. Measurement of an external signal’s duty cycle requires that the trigger edge is changed after each capture. Changing the edge sensing must be done as early as possible after the ICR1 Register has been read. After a change of the edge, the Input Capture Flag (ICF1) must be cleared by software (writing a logical one to the I/O bit location). For measuring frequency only, the clearing of the ICF1 Flag is not required (if an interrupt handler is used). 16.7 Output Compare Units The 16-bit comparator continuously compares TCNT1 with the Output Compare Register (OCR1x). If TCNT equals OCR1x the comparator signals a match. A match will set the Output Compare Flag (OCF1x) at the next timer clock cycle. If enabled (OCIE1x = 1), the Output Compare Flag generates an Output Compare interrupt. The OCF1x Flag is automatically cleared when the interrupt is executed. Alternatively the OCF1x Flag can be cleared by software by writing a logical one to its I/O bit location. The Waveform Generator uses the match signal to generate an output according to operating mode set by the Waveform Generation mode (WGM13:0) bits and Compare Output mode (COM1x1:0) bits. The TOP and BOTTOM signals are used by the Waveform Generator for handling the special cases of the extreme values in some modes of operation (See “Modes of Operation” on page 123.) A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (i.e., counter resolution). In addition to the counter resolution, the TOP value defines the period time for waveforms generated by the Waveform Generator. Figure 16-4 shows a block diagram of the Output Compare unit. The small “n” in the register and bit names indicates the device number (n = 1 for Timer/Counter 1), and the “x” indicates Output Compare unit (A/B). The elements of the block diagram that are not directly a part of the Output Compare unit are gray shaded.120 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 16-4. Output Compare Unit, Block Diagram The OCR1x Register is double buffered when using any of the twelve Pulse Width Modulation (PWM) modes. For the Normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR1x Compare Register to either TOP or BOTTOM of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR1x Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR1x Buffer Register, and if double buffering is disabled the CPU will access the OCR1x directly. The content of the OCR1x (Buffer or Compare) Register is only changed by a write operation (the Timer/Counter does not update this register automatically as the TCNT1 and ICR1 Register). Therefore OCR1x is not read via the high byte temporary register (TEMP). However, it is a good practice to read the low byte first as when accessing other 16-bit registers. Writing the OCR1x Registers must be done via the TEMP Register since the compare of all 16 bits is done continuously. The high byte (OCR1xH) has to be written first. When the high byte I/O location is written by the CPU, the TEMP Register will be updated by the value written. Then when the low byte (OCR1xL) is written to the lower eight bits, the high byte will be copied into the upper 8-bits of either the OCR1x buffer or OCR1x Compare Register in the same system clock cycle. For more information of how to access the 16-bit registers refer to “Accessing 16-bit Registers” on page 113. 16.7.1 Force Output Compare In non-PWM Waveform Generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC1x) bit. Forcing compare match will not set the OCF1x Flag or reload/clear the timer, but the OC1x pin will be updated as if a real compare match had occurred (the COM11:0 bits settings define whether the OC1x pin is set, cleared or toggled). OCFnx (Int.Req.) = (16-bit Comparator ) OCRnx Buffer (16-bit Register) OCRnxH Buf. (8-bit) OCnx TEMP (8-bit) DATA BUS (8-bit) OCRnxL Buf. (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) WGMn3:0 COMnx1:0 OCRnx (16-bit Register) OCRnxH (8-bit) OCRnxL (8-bit) Waveform Generator TOP BOTTOM121 2552K–AVR–04/11 ATmega329/3290/649/6490 16.7.2 Compare Match Blocking by TCNT1 Write All CPU writes to the TCNT1 Register will block any compare match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR1x to be initialized to the same value as TCNT1 without triggering an interrupt when the Timer/Counter clock is enabled. 16.7.3 Using the Output Compare Unit Since writing TCNT1 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT1 when using any of the Output Compare units, independent of whether the Timer/Counter is running or not. If the value written to TCNT1 equals the OCR1x value, the compare match will be missed, resulting in incorrect waveform generation. Do not write the TCNT1 equal to TOP in PWM modes with variable TOP values. The compare match for the TOP will be ignored and the counter will continue to 0xFFFF. Similarly, do not write the TCNT1 value equal to BOTTOM when the counter is counting down. The setup of the OC1x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC1x value is to use the Force Output Compare (FOC1x) strobe bits in Normal mode. The OC1x Register keeps its value even when changing between Waveform Generation modes. Be aware that the COM1x1:0 bits are not double buffered together with the compare value. Changing the COM1x1:0 bits will take effect immediately.122 2552K–AVR–04/11 ATmega329/3290/649/6490 16.8 Compare Match Output Unit The Compare Output mode (COM1x1:0) bits have two functions. The Waveform Generator uses the COM1x1:0 bits for defining the Output Compare (OC1x) state at the next compare match. Secondly the COM1x1:0 bits control the OC1x pin output source. Figure 16-5 shows a simplified schematic of the logic affected by the COM1x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM1x1:0 bits are shown. When referring to the OC1x state, the reference is for the internal OC1x Register, not the OC1x pin. If a system reset occur, the OC1x Register is reset to “0”. Figure 16-5. Compare Match Output Unit, Schematic The general I/O port function is overridden by the Output Compare (OC1x) from the Waveform Generator if either of the COM1x1:0 bits are set. However, the OC1x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC1x pin (DDR_OC1x) must be set as output before the OC1x value is visible on the pin. The port override function is generally independent of the Waveform Generation mode, but there are some exceptions. Refer to Table 16-2, Table 16-3 and Table 16-4 for details. The design of the Output Compare pin logic allows initialization of the OC1x state before the output is enabled. Note that some COM1x1:0 bit settings are reserved for certain modes of operation. See “Register Description” on page 132. The COM1x1:0 bits have no effect on the Input Capture unit. PORT DDR D Q D Q OCnx OCnx Pin D Q Waveform Generator COMnx1 COMnx0 0 1 DATA BUS FOCnx clkI/O123 2552K–AVR–04/11 ATmega329/3290/649/6490 16.8.1 Compare Output Mode and Waveform Generation The Waveform Generator uses the COM1x1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM1x1:0 = 0 tells the Waveform Generator that no action on the OC1x Register is to be performed on the next compare match. For compare output actions in the non-PWM modes refer to Table 16-2 on page 132. For fast PWM mode refer to Table 16-3 on page 133, and for phase correct and phase and frequency correct PWM refer to Table 16-4 on page 133. A change of the COM1x1:0 bits state will have effect at the first compare match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC1x strobe bits. 16.9 Modes of Operation The mode of operation, i.e., the behavior of the Timer/Counter and the Output Compare pins, is defined by the combination of the Waveform Generation mode (WGM13:0) and Compare Output mode (COM1x1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM1x1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM1x1:0 bits control whether the output should be set, cleared or toggle at a compare match (See “Compare Match Output Unit” on page 122.) For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 130. 16.9.1 Normal Mode The simplest mode of operation is the Normal mode (WGM13:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 16-bit value (MAX = 0xFFFF) and then restarts from the BOTTOM (0x0000). In normal operation the Timer/Counter Overflow Flag (TOV1) will be set in the same timer clock cycle as the TCNT1 becomes zero. The TOV1 Flag in this case behaves like a 17th bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV1 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Input Capture unit is easy to use in Normal mode. However, observe that the maximum interval between the external events must not exceed the resolution of the counter. If the interval between events are too long, the timer overflow interrupt or the prescaler must be used to extend the resolution for the capture unit. The Output Compare units can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 16.9.2 Clear Timer on Compare Match (CTC) Mode In Clear Timer on Compare or CTC mode (WGM13:0 = 4 or 12), the OCR1A or ICR1 Register are used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT1) matches either the OCR1A (WGM13:0 = 4) or the ICR1 (WGM13:0 = 12). The OCR1A or ICR1 define the top value for the counter, hence also its resolution. This124 2552K–AVR–04/11 ATmega329/3290/649/6490 mode allows greater control of the compare match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 16-6. The counter value (TCNT1) increases until a compare match occurs with either OCR1A or ICR1, and then counter (TCNT1) is cleared. Figure 16-6. CTC Mode, Timing Diagram An interrupt can be generated at each time the counter value reaches the TOP value by either using the OCF1A or ICF1 Flag according to the register used to define the TOP value. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR1A or ICR1 is lower than the current value of TCNT1, the counter will miss the compare match. The counter will then have to count to its maximum value (0xFFFF) and wrap around starting at 0x0000 before the compare match can occur. In many cases this feature is not desirable. An alternative will then be to use the fast PWM mode using OCR1A for defining TOP (WGM13:0 = 15) since the OCR1A then will be double buffered. For generating a waveform output in CTC mode, the OC1A output can be set to toggle its logical level on each compare match by setting the Compare Output mode bits to toggle mode (COM1A1:0 = 1). The OC1A value will not be visible on the port pin unless the data direction for the pin is set to output (DDR_OC1A = 1). The waveform generated will have a maximum frequency of fOC1A = fclk_I/O/2 when OCR1A is set to zero (0x0000). The waveform frequency is defined by the following equation: The N variable represents the prescaler factor (1, 8, 64, 256, or 1024). As for the Normal mode of operation, the TOV1 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x0000. 16.9.3 Fast PWM Mode The fast Pulse Width Modulation or fast PWM mode (WGM13:0 = 5, 6, 7, 14, or 15) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM options by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the compare match between TCNT1 and OCR1x, and set at BOTTOM. In inverting Compare TCNTn OCnA (Toggle) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 (COMnA1:0 = 1) f OCnA f clk_I/O 2 ⋅ ⋅ N ( ) 1 + OCRnA = --------------------------------------------------125 2552K–AVR–04/11 ATmega329/3290/649/6490 Output mode output is set on compare match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct and phase and frequency correct PWM modes that use dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), hence reduces total system cost. The PWM resolution for fast PWM can be fixed to 8-, 9-, or 10-bit, or defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated by using the following equation: In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGM13:0 = 5, 6, or 7), the value in ICR1 (WGM13:0 = 14), or the value in OCR1A (WGM13:0 = 15). The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 16-7. The figure shows fast PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a compare match occurs. Figure 16-7. Fast PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set each time the counter reaches TOP. In addition the OC1A or ICF1 Flag is set at the same timer clock cycle as TOV1 is set when either OCR1A or ICR1 is used for defining the TOP value. If one of the interrupts are enabled, the interrupt handler routine can be used for updating the TOP and compare values. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a compare match will never occur between the TCNT1 and the OCR1x. Note that when using fixed TOP values the unused bits are masked to zero when any of the OCR1x Registers are written. RFPWM log( ) TOP + 1 log( ) 2 = ----------------------------------- TCNTn OCRnx / TOP Update and TOVn Interrupt Flag Set and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 5 6 7 8 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)126 2552K–AVR–04/11 ATmega329/3290/649/6490 The procedure for updating ICR1 differs from updating OCR1A when used for defining the TOP value. The ICR1 Register is not double buffered. This means that if ICR1 is changed to a low value when the counter is running with none or a low prescaler value, there is a risk that the new ICR1 value written is lower than the current value of TCNT1. The result will then be that the counter will miss the compare match at the TOP value. The counter will then have to count to the MAX value (0xFFFF) and wrap around starting at 0x0000 before the compare match can occur. The OCR1A Register however, is double buffered. This feature allows the OCR1A I/O location to be written anytime. When the OCR1A I/O location is written the value written will be put into the OCR1A Buffer Register. The OCR1A Compare Register will then be updated with the value in the Buffer Register at the next timer clock cycle the TCNT1 matches TOP. The update is done at the same timer clock cycle as the TCNT1 is cleared and the TOV1 Flag is set. Using the ICR1 Register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A Register is free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed (by changing the TOP value), using the OCR1A as TOP is clearly a better choice due to its double buffer feature. In fast PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to three (see Table 16-3 on page 133). The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the compare match between OCR1x and TCNT1, and clearing (or setting) the OC1x Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represents special cases when generating a PWM waveform output in the fast PWM mode. If the OCR1x is set equal to BOTTOM (0x0000) the output will be a narrow spike for each TOP+1 timer clock cycle. Setting the OCR1x equal to TOP will result in a constant high or low output (depending on the polarity of the output set by the COM1x1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC1A to toggle its logical level on each compare match (COM1A1:0 = 1). This applies only if OCR1A is used to define the TOP value (WGM13:0 = 15). The waveform generated will have a maximum frequency of fOC1A = fclk_I/O/2 when OCR1A is set to zero (0x0000). This feature is similar to the OC1A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 16.9.4 Phase Correct PWM Mode The phase correct Pulse Width Modulation or phase correct PWM mode (WGM13:0 = 1, 2, 3, 10, or 11) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is, like the phase and frequency correct PWM mode, based on a dualslope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the compare match between TCNT1 and OCR1x while counting up, and set on the compare match while counting down. In inverting Output Compare mode, the operation is f OCnxPWM f clk_I/O N ⋅ ( ) 1 + TOP = -----------------------------------127 2552K–AVR–04/11 ATmega329/3290/649/6490 inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode can be fixed to 8-, 9-, or 10-bit, or defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated by using the following equation: In phase correct PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGM13:0 = 1, 2, or 3), the value in ICR1 (WGM13:0 = 10), or the value in OCR1A (WGM13:0 = 11). The counter has then reached the TOP and changes the count direction. The TCNT1 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 16-8. The figure shows phase correct PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a compare match occurs. Figure 16-8. Phase Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set each time the counter reaches BOTTOM. When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 Flag is set accordingly at the same timer clock cycle as the OCR1x Registers are updated with the double buffer value (at TOP). The Interrupt Flags can be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a compare match will never occur between the TCNT1 and the OCR1x. RPCPWM log( ) TOP + 1 log( ) 2 = ----------------------------------- OCRnx/TOP Update and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) 1 2 3 4 TOVn Interrupt Flag Set (Interrupt on Bottom) TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)128 2552K–AVR–04/11 ATmega329/3290/649/6490 Note that when using fixed TOP values, the unused bits are masked to zero when any of the OCR1x Registers are written. As the third period shown in Figure 16-8 illustrates, changing the TOP actively while the Timer/Counter is running in the phase correct mode can result in an unsymmetrical output. The reason for this can be found in the time of update of the OCR1x Register. Since the OCR1x update occurs at TOP, the PWM period starts and ends at TOP. This implies that the length of the falling slope is determined by the previous TOP value, while the length of the rising slope is determined by the new TOP value. When these two values differ the two slopes of the period will differ in length. The difference in length gives the unsymmetrical result on the output. It is recommended to use the phase and frequency correct mode instead of the phase correct mode when changing the TOP value while the Timer/Counter is running. When using a static TOP value there are practically no differences between the two modes of operation. In phase correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to three (See Table 1 on page 133). The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the compare match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x Register at compare match between OCR1x and TCNT1 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WGM13:0 = 11) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. 16.9.5 Phase and Frequency Correct PWM Mode The phase and frequency correct Pulse Width Modulation, or phase and frequency correct PWM mode (WGM13:0 = 8 or 9) provides a high resolution phase and frequency correct PWM waveform generation option. The phase and frequency correct PWM mode is, like the phase correct PWM mode, based on a dual-slope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the compare match between TCNT1 and OCR1x while counting up, and set on the compare match while counting down. In inverting Compare Output mode, the operation is inverted. The dual-slope operation gives a lower maximum operation frequency compared to the single-slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The main difference between the phase correct, and the phase and frequency correct PWM mode is the time the OCR1x Register is updated by the OCR1x Buffer Register, (see Figure 16- 8 and Figure 16-9). f OCnxPCPWM f clk_I/O 2 ⋅ ⋅ N TOP = ----------------------------129 2552K–AVR–04/11 ATmega329/3290/649/6490 The PWM resolution for the phase and frequency correct PWM mode can be defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated using the following equation: In phase and frequency correct PWM mode the counter is incremented until the counter value matches either the value in ICR1 (WGM13:0 = 8), or the value in OCR1A (WGM13:0 = 9). The counter has then reached the TOP and changes the count direction. The TCNT1 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct and frequency correct PWM mode is shown on Figure 16-9. The figure shows phase and frequency correct PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes noninverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a compare match occurs. Figure 16-9. Phase and Frequency Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set at the same timer clock cycle as the OCR1x Registers are updated with the double buffer value (at BOTTOM). When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 Flag set when TCNT1 has reached TOP. The Interrupt Flags can then be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a compare match will never occur between the TCNT1 and the OCR1x. As Figure 16-9 shows the output generated is, in contrast to the phase correct mode, symmetrical in all periods. Since the OCR1x Registers are updated at BOTTOM, the length of the rising and the falling slopes will always be equal. This gives symmetrical output pulses and is therefore frequency correct. RPFCPWM log( ) TOP + 1 log( ) 2 = ----------------------------------- OCRnx/TOP Updateand TOVn Interrupt Flag Set (Interrupt on Bottom) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) 1 2 3 4 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)130 2552K–AVR–04/11 ATmega329/3290/649/6490 Using the ICR1 Register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A Register is free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed by changing the TOP value, using the OCR1A as TOP is clearly a better choice due to its double buffer feature. In phase and frequency correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to three (See Table 1 on page 133). The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the compare match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x Register at compare match between OCR1x and TCNT1 when the counter decrements. The PWM frequency for the output when using phase and frequency correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represents special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be set to high for noninverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. 16.10 Timer/Counter Timing Diagrams The Timer/Counter is a synchronous design and the timer clock (clkT1) is therefore shown as a clock enable signal in the following figures. The figures include information on when Interrupt Flags are set, and when the OCR1x Register is updated with the OCR1x buffer value (only for modes utilizing double buffering). Figure 16-10 shows a timing diagram for the setting of OCF1x. Figure 16-10. Timer/Counter Timing Diagram, Setting of OCF1x, no Prescaling Figure 16-11 shows the same timing data, but with the prescaler enabled. f OCnxPFCPWM f clk_I/O 2 ⋅ ⋅ N TOP = ---------------------------- clkTn (clkI/O/1) OCFnx clkI/O OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2131 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 16-11. Timer/Counter Timing Diagram, Setting of OCF1x, with Prescaler (fclk_I/O/8) Figure 16-12 shows the count sequence close to TOP in various modes. When using phase and frequency correct PWM mode the OCR1x Register is updated at BOTTOM. The timing diagrams will be the same, but TOP should be replaced by BOTTOM, TOP-1 by BOTTOM+1 and so on. The same renaming applies for modes that set the TOV1 Flag at BOTTOM. Figure 16-12. Timer/Counter Timing Diagram, no Prescaling Figure 16-13 shows the same timing data, but with the prescaler enabled. OCFnx OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8) TOVn (FPWM) and ICFn (if used as TOP) OCRnx (Update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx Value New OCRnx Value TOP - 1 TOP BOTTOM BOTTOM + 1 clkTn (clkI/O/1) clkI/O132 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 16-13. Timer/Counter Timing Diagram, with Prescaler (fclk_I/O/8) 16.11 Register Description 16.11.1 TCCR1A – Timer/Counter1 Control Register A • Bit 7:6 – COM1A1:0: Compare Output Mode for Unit A • Bit 5:4 – COM1B1:0: Compare Output Mode for Unit B The COM1A1:0 and COM1B1:0 control the Output Compare pins (OC1A and OC1B respectively) behavior. If one or both of the COM1A1:0 bits are written to one, the OC1A output overrides the normal port functionality of the I/O pin it is connected to. If one or both of the COM1B1:0 bit are written to one, the OC1B output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC1A or OC1B pin must be set in order to enable the output driver. When the OC1A or OC1B is connected to the pin, the function of the COM1x1:0 bits is dependent of the WGM13:0 bits setting. Table 16-2 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to a Normal or a CTC mode (non-PWM). TOVn (FPWM) and ICFn (if used as TOP) OCRnx (Update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx Value New OCRnx Value TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) Bit 7 6 5 4 3 2 1 0 (0x80) COM1A1 COM1A0 COM1B1 COM1B0 – – WGM11 WGM10 TCCR1A Read/Write R/W R/W R/W R/W R R R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 16-2. Compare Output Mode, non-PWM COM1A1/COM1B1 COM1A0/COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 Toggle OC1A/OC1B on Compare Match. 1 0 Clear OC1A/OC1B on Compare Match (Set output to low level). 1 1 Set OC1A/OC1B on Compare Match (Set output to high level).133 2552K–AVR–04/11 ATmega329/3290/649/6490 Table 16-3 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the fast PWM mode. Note: 1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. In this case the compare match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on page 124. for more details. Table 16-4 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the phase correct or the phase and frequency correct, PWM mode. Note: 1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. See “Phase Correct PWM Mode” on page 126. for more details. • Bit 1:0 – WGM11:0: Waveform Generation Mode Combined with the WGM13:2 bits found in the TCCR1B Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 16-5. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare match (CTC) mode, and three types of Pulse Width Modulation (PWM) modes. (See “Modes of Operation” on page 123.). Table 16-3. Compare Output Mode, Fast PWM(1) COM1A1/COM1B1 COM1A0/COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 WGM13:0 = 14 or 15: Toggle OC1A on Compare Match, OC1B disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B disconnected. 1 0 Clear OC1A/OC1B on Compare Match, set OC1A/OC1B at BOTTOM (non-inverting mode). 1 1 Set OC1A/OC1B on Compare Match, clear OC1A/OC1B at BOTTOM (inverting mode). Table 16-4. Compare Output Mode, Phase Correct and Phase and Frequency Correct PWM(1) COM1A1/COM1B1 COM1A0/COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 WGM13:0 = 9 or 11: Toggle OC1A on Compare Match, OC1B disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B disconnected. 1 0 Clear OC1A/OC1B on Compare Match when upcounting. Set OC1A/OC1B on Compare Match when counting down. 1 1 Set OC1A/OC1B on Compare Match when upcounting. Clear OC1A/OC1B on Compare Match when counting down.134 2552K–AVR–04/11 ATmega329/3290/649/6490 Note: 1. The CTC1 and PWM11:0 bit definition names are obsolete. Use the WGM12:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer. 16.11.2 TCCR1B – Timer/Counter1 Control Register B • Bit 7 – ICNC1: Input Capture Noise Canceler Setting this bit (to one) activates the Input Capture Noise Canceler. When the noise canceler is activated, the input from the Input Capture pin (ICP1) is filtered. The filter function requires four successive equal valued samples of the ICP1 pin for changing its output. The Input Capture is therefore delayed by four Oscillator cycles when the noise canceler is enabled. • Bit 6 – ICES1: Input Capture Edge Select This bit selects which edge on the Input Capture pin (ICP1) that is used to trigger a capture event. When the ICES1 bit is written to zero, a falling (negative) edge is used as trigger, and when the ICES1 bit is written to one, a rising (positive) edge will trigger the capture. When a capture is triggered according to the ICES1 setting, the counter value is copied into the Input Capture Register (ICR1). The event will also set the Input Capture Flag (ICF1), and this can be used to cause an Input Capture Interrupt, if this interrupt is enabled. Table 16-5. Waveform Generation Mode Bit Description(1) Mode WGM13 WGM12 (CTC1) WGM11 (PWM11) WGM10 (PWM10) Timer/Counter Mode of Operation TOP Update of OCR1x at TOV1 Flag Set on 00 0 0 0 Normal 0xFFFF Immediate MAX 1 0 0 0 1 PWM, Phase Correct, 8-bit 0x00FF TOP BOTTOM 2 0 0 1 0 PWM, Phase Correct, 9-bit 0x01FF TOP BOTTOM 3 0 0 1 1 PWM, Phase Correct, 10-bit 0x03FF TOP BOTTOM 4 0 1 0 0 CTC OCR1A Immediate MAX 5 0 1 0 1 Fast PWM, 8-bit 0x00FF BOTTOM TOP 6 0 1 1 0 Fast PWM, 9-bit 0x01FF BOTTOM TOP 7 0 1 1 1 Fast PWM, 10-bit 0x03FF BOTTOM TOP 8 1 0 0 0 PWM, Phase and Frequency Correct ICR1 BOTTOM BOTTOM 9 1 0 0 1 PWM, Phase and Frequency Correct OCR1A BOTTOM BOTTOM 10 1 0 1 0 PWM, Phase Correct ICR1 TOP BOTTOM 11 1 0 1 1 PWM, Phase Correct OCR1A TOP BOTTOM 12 1 1 0 0 CTC ICR1 Immediate MAX 13 1 1 0 1 (Reserved) – – – 14 1 1 1 0 Fast PWM ICR1 BOTTOM TOP 15 1 1 1 1 Fast PWM OCR1A BOTTOM TOP Bit 7 6 5 4 3 2 1 0 (0x81) ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 TCCR1B Read/Write R/W R/W R R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0135 2552K–AVR–04/11 ATmega329/3290/649/6490 When the ICR1 is used as TOP value (see description of the WGM13:0 bits located in the TCCR1A and the TCCR1B Register), the ICP1 is disconnected and consequently the Input Capture function is disabled. • Bit 5 – Reserved Bit This bit is reserved for future use. For ensuring compatibility with future devices, this bit must be written to zero when TCCR1B is written. • Bit 4:3 – WGM13:2: Waveform Generation Mode See TCCR1A Register description. • Bit 2:0 – CS12:0: Clock Select The three Clock Select bits select the clock source to be used by the Timer/Counter, see Figure 16-10 and Figure 16-11. If external pin modes are used for the Timer/Counter1, transitions on the T1 pin will clock the counter even if the pin is configured as an output. This feature allows software control of the counting. 16.11.3 TCCR1C – Timer/Counter1 Control Register C • Bit 7 – FOC1A: Force Output Compare for Unit A • Bit 6 – FOC1B: Force Output Compare for Unit B The FOC1A/FOC1B bits are only active when the WGM13:0 bits specifies a non-PWM mode. However, for ensuring compatibility with future devices, these bits must be set to zero when TCCR1A is written when operating in a PWM mode. When writing a logical one to the FOC1A/FOC1B bit, an immediate compare match is forced on the Waveform Generation unit. The OC1A/OC1B output is changed according to its COM1x1:0 bits setting. Note that the FOC1A/FOC1B bits are implemented as strobes. Therefore it is the value present in the COM1x1:0 bits that determine the effect of the forced compare. Table 16-6. Clock Select Bit Description CS12 CS11 CS10 Description 000 No clock source (Timer/Counter stopped). 0 0 1 clkI/O/1 (No prescaling) 0 1 0 clkI/O/8 (From prescaler) 0 1 1 clkI/O/64 (From prescaler) 1 0 0 clkI/O/256 (From prescaler) 1 0 1 clkI/O/1024 (From prescaler) 1 1 0 External clock source on T1 pin. Clock on falling edge. 1 1 1 External clock source on T1 pin. Clock on rising edge. Bit 7 6 5 4 3 2 1 0 (0x82) FOC1A FOC1B – – – – – – TCCR1C Read/Write R/W R/W R R R R R R Initial Value 0 0 0 0 0 0 0 0136 2552K–AVR–04/11 ATmega329/3290/649/6490 A FOC1A/FOC1B strobe will not generate any interrupt nor will it clear the timer in Clear Timer on Compare match (CTC) mode using OCR1A as TOP. The FOC1A/FOC1B bits are always read as zero. 16.11.4 TCNT1H and TCNT1L – Timer/Counter1 The two Timer/Counter I/O locations (TCNT1H and TCNT1L, combined TCNT1) give direct access, both for read and for write operations, to the Timer/Counter unit 16-bit counter. To ensure that both the high and low bytes are read and written simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 113. Modifying the counter (TCNT1) while the counter is running introduces a risk of missing a compare match between TCNT1 and one of the OCR1x Registers. Writing to the TCNT1 Register blocks (removes) the compare match on the following timer clock for all compare units. 16.11.5 OCR1AH and OCR1AL – Output Compare Register 1 A 16.11.6 OCR1BH and OCR1BL – Output Compare Register 1 B The Output Compare Registers contain a 16-bit value that is continuously compared with the counter value (TCNT1). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC1x pin. The Output Compare Registers are 16-bit in size. To ensure that both the high and low bytes are written simultaneously when the CPU writes to these registers, the access is performed using an 8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 113. Bit 7 6 5 4 3 2 1 0 (0x85) TCNT1[15:8] TCNT1H (0x84) TCNT1[7:0] TCNT1L Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0x89) OCR1A[15:8] OCR1AH (0x88) OCR1A[7:0] OCR1AL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0x8B) OCR1B[15:8] OCR1BH (0x8A) OCR1B[7:0] OCR1BL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0137 2552K–AVR–04/11 ATmega329/3290/649/6490 16.11.7 ICR1H and ICR1L – Input Capture Register 1 The Input Capture is updated with the counter (TCNT1) value each time an event occurs on the ICP1 pin (or optionally on the Analog Comparator output for Timer/Counter1). The Input Capture can be used for defining the counter TOP value. The Input Capture Register is 16-bit in size. To ensure that both the high and low bytes are read simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 113. 16.11.8 TIMSK1 – Timer/Counter1 Interrupt Mask Register • Bit 5 – ICIE1: Timer/Counter1, Input Capture Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Input Capture interrupt is enabled. The corresponding Interrupt Vector (See “Interrupts” on page 49.) is executed when the ICF1 Flag, located in TIFR1, is set. • Bit 2 – OCIE1B: Timer/Counter1, Output Compare B Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Output Compare B Match interrupt is enabled. The corresponding Interrupt Vector (See “Interrupts” on page 49.) is executed when the OCF1B Flag, located in TIFR1, is set. • Bit 1 – OCIE1A: Timer/Counter1, Output Compare A Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Output Compare A Match interrupt is enabled. The corresponding Interrupt Vector (See “Interrupts” on page 49.) is executed when the OCF1A Flag, located in TIFR1, is set. • Bit 0 – TOIE1: Timer/Counter1, Overflow Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Overflow interrupt is enabled. The corresponding Interrupt Vector (See “Interrupts” on page 49.) is executed when the TOV1 Flag, located in TIFR1, is set. Bit 7 6 5 4 3 2 1 0 (0x87) ICR1[15:8] ICR1H (0x86) ICR1[7:0] ICR1L Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0x6F) – – ICIE1 – – OCIE1B OCIE1A TOIE1 TIMSK1 Read/Write R R R/W R R R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0138 2552K–AVR–04/11 ATmega329/3290/649/6490 16.11.9 TIFR1 – Timer/Counter1 Interrupt Flag Register • Bit 5 – ICF1: Timer/Counter1, Input Capture Flag This flag is set when a capture event occurs on the ICP1 pin. When the Input Capture Register (ICR1) is set by the WGM13:0 to be used as the TOP value, the ICF1 Flag is set when the counter reaches the TOP value. ICF1 is automatically cleared when the Input Capture Interrupt Vector is executed. Alternatively, ICF1 can be cleared by writing a logic one to its bit location. • Bit 2 – OCF1B: Timer/Counter1, Output Compare B Match Flag This flag is set in the timer clock cycle after the counter (TCNT1) value matches the Output Compare Register B (OCR1B). Note that a Forced Output Compare (FOC1B) strobe will not set the OCF1B Flag. OCF1B is automatically cleared when the Output Compare Match B Interrupt Vector is executed. Alternatively, OCF1B can be cleared by writing a logic one to its bit location. Bit 1 – OCF1A: Timer/Counter1, Output Compare A Match Flag This flag is set in the timer clock cycle after the counter (TCNT1) value matches the Output Compare Register A (OCR1A). Note that a Forced Output Compare (FOC1A) strobe will not set the OCF1A Flag. OCF1A is automatically cleared when the Output Compare Match A Interrupt Vector is executed. Alternatively, OCF1A can be cleared by writing a logic one to its bit location. • Bit 0 – TOV1: Timer/Counter1, Overflow Flag The setting of this flag is dependent of the WGM13:0 bits setting. In Normal and CTC modes, the TOV1 Flag is set when the timer overflows. Refer to Table 16-5 on page 134 for the TOV1 Flag behavior when using another WGM13:0 bit setting. TOV1 is automatically cleared when the Timer/Counter1 Overflow Interrupt Vector is executed. Alternatively, TOV1 can be cleared by writing a logic one to its bit location. Bit 7 6 5 4 3 2 1 0 0x16 (0x36) – – ICF1 – – OCF1B OCF1A TOV1 TIFR1 Read/Write R R R/W R R R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0139 2552K–AVR–04/11 ATmega329/3290/649/6490 17. 8-bit Timer/Counter2 with PWM and Asynchronous Operation 17.1 Features Timer/Counter2 is a general purpose, single compare unit, 8-bit Timer/Counter module. The main features are: • Single Compare Unit Counter • Clear Timer on Compare Match (Auto Reload) • Glitch-free, Phase Correct Pulse Width Modulator (PWM) • Frequency Generator • 10-bit Clock Prescaler • Overflow and Compare Match Interrupt Sources (TOV2 and OCF2A) • Allows Clocking from External 32kHz Watch Crystal Independent of the I/O Clock 17.2 Overview A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 17-1. For the actual placement of I/O pins, refer to “Pinout ATmega3290/6490” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “Register Description” on page 153. Figure 17-1. 8-bit Timer/Counter Block Diagram Timer/Counter DATA BUS = TCNTn Waveform Generation OCnx = 0 Control Logic = 0xFF BOTTOM TOP count clear direction TOVn (Int.Req.) OCnx (Int.Req.) Synchronization Unit OCRnx TCCRnx ASSRn Status flags clkI/O clkASY Synchronized Status flags asynchronous mode select (ASn) TOSC1 T/C Oscillator TOSC2 Prescaler clkTn clkI/O140 2552K–AVR–04/11 ATmega329/3290/649/6490 17.2.1 Registers The Timer/Counter (TCNT2) and Output Compare Register (OCR2A) are 8-bit registers. Interrupt request (shorten as Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFR2). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK2). TIFR2 and TIMSK2 are not shown in the figure. The Timer/Counter can be clocked internally, via the prescaler, or asynchronously clocked from the TOSC1/2 pins, as detailed later in this section. The asynchronous operation is controlled by the Asynchronous Status Register (ASSR). The Clock Select logic block controls which clock source the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the Clock Select logic is referred to as the timer clock (clkT2). The double buffered Output Compare Register (OCR2A) is compared with the Timer/Counter value at all times. The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pin (OC2A). See “Output Compare Unit” on page 141. for details. The compare match event will also set the Compare Flag (OCF2A) which can be used to generate an Output Compare interrupt request. 17.2.2 Definitions Many register and bit references in this document are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 2. However, when using the register or bit defines in a program, the precise form must be used, i.e., TCNT2 for accessing Timer/Counter2 counter value and so on. The definitions in Table 17-1 are also used extensively throughout the section. 17.3 Timer/Counter Clock Sources The Timer/Counter can be clocked by an internal synchronous or an external asynchronous clock source. The clock source clkT2 is by default equal to the MCU clock, clkI/O. When the AS2 bit in the ASSR Register is written to logic one, the clock source is taken from the Timer/Counter Oscillator connected to TOSC1 and TOSC2. For details on asynchronous operation, see “ASSR – Asynchronous Status Register” on page 155. For details on clock sources and prescaler, see “Timer/Counter Prescaler” on page 152. 17.4 Counter Unit The main part of the 8-bit Timer/Counter is the programmable bi-directional counter unit. Figure 17-2 shows a block diagram of the counter and its surrounding environment. Table 17-1. Definitions of Timer/Counter values. BOTTOM The counter reaches the BOTTOM when it becomes zero (0x00). MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be the fixed value 0xFF (MAX) or the value stored in the OCR2A Register. The assignment is dependent on the mode of operation.141 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 17-2. Counter Unit Block Diagram Signal description (internal signals): count Increment or decrement TCNT2 by 1. direction Selects between increment and decrement. clear Clear TCNT2 (set all bits to zero). clkT2 Timer/Counter clock. top Signalizes that TCNT2 has reached maximum value. bottom Signalizes that TCNT2 has reached minimum value (zero). Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT2). clkT2 can be generated from an external or internal clock source, selected by the Clock Select bits (CS22:0). When no clock source is selected (CS22:0 = 0) the timer is stopped. However, the TCNT2 value can be accessed by the CPU, regardless of whether clkT2 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the WGM21 and WGM20 bits located in the Timer/Counter Control Register (TCCR2A). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare output OC2A. For more details about advanced counting sequences and waveform generation, see “Modes of Operation” on page 145. The Timer/Counter Overflow Flag (TOV2) is set according to the mode of operation selected by the WGM21:0 bits. TOV2 can be used for generating a CPU interrupt. 17.5 Output Compare Unit The 8-bit comparator continuously compares TCNT2 with the Output Compare Register (OCR2A). Whenever TCNT2 equals OCR2A, the comparator signals a match. A match will set the Output Compare Flag (OCF2A) at the next timer clock cycle. If enabled (OCIE2A = 1), the Output Compare Flag generates an Output Compare interrupt. The OCF2A Flag is automatically cleared when the interrupt is executed. Alternatively, the OCF2A Flag can be cleared by software by writing a logical one to its I/O bit location. The Waveform Generator uses the match signal to generate an output according to operating mode set by the WGM21:0 bits and Compare Output mode (COM2A1:0) bits. The max and bottom signals are used by the Waveform Generator for handling the special cases of the extreme values in some modes of operation (“Modes of Operation” on page 145). Figure 17-3 shows a block diagram of the Output Compare unit. DATA BUS TCNTn Control Logic count TOVn (Int.Req.) bottom top direction clear TOSC1 T/C Oscillator TOSC2 Prescaler clkI/O clk Tn142 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 17-3. Output Compare Unit, Block Diagram The OCR2A Register is double buffered when using any of the Pulse Width Modulation (PWM) modes. For the Normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR2A Compare Register to either top or bottom of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR2A Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR2A Buffer Register, and if double buffering is disabled the CPU will access the OCR2A directly. 17.5.1 Force Output Compare In non-PWM waveform generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC2A) bit. Forcing compare match will not set the OCF2A Flag or reload/clear the timer, but the OC2A pin will be updated as if a real compare match had occurred (the COM2A1:0 bits settings define whether the OC2A pin is set, cleared or toggled). 17.5.2 Compare Match Blocking by TCNT2 Write All CPU write operations to the TCNT2 Register will block any compare match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR2A to be initialized to the same value as TCNT2 without triggering an interrupt when the Timer/Counter clock is enabled. 17.5.3 Using the Output Compare Unit Since writing TCNT2 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT2 when using the Output Compare unit, independently of whether the Timer/Counter is running or not. If the value written to TCNT2 equals the OCR2A value, the compare match will be missed, resulting in incorrect waveform generation. Similarly, do not write the TCNT2 value equal to BOTTOM when the counter is counting down. OCFnx (Int.Req.) = (8-bit Comparator ) OCRnx OCnx DATA BUS TCNTn WGMn1:0 Waveform Generator top FOCn COMnX1:0 bottom143 2552K–AVR–04/11 ATmega329/3290/649/6490 The setup of the OC2A should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC2A value is to use the Force Output Compare (FOC2A) strobe bit in Normal mode. The OC2A Register keeps its value even when changing between Waveform Generation modes. Be aware that the COM2A1:0 bits are not double buffered together with the compare value. Changing the COM2A1:0 bits will take effect immediately.144 2552K–AVR–04/11 ATmega329/3290/649/6490 17.6 Compare Match Output Unit The Compare Output mode (COM2A1:0) bits have two functions. The Waveform Generator uses the COM2A1:0 bits for defining the Output Compare (OC2A) state at the next compare match. Also, the COM2A1:0 bits control the OC2A pin output source. Figure 17-4 shows a simplified schematic of the logic affected by the COM2A1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM2A1:0 bits are shown. When referring to the OC2A state, the reference is for the internal OC2A Register, not the OC2A pin. Figure 17-4. Compare Match Output Unit, Schematic The general I/O port function is overridden by the Output Compare (OC2A) from the Waveform Generator if either of the COM2A1:0 bits are set. However, the OC2A pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC2A pin (DDR_OC2A) must be set as output before the OC2A value is visible on the pin. The port override function is independent of the Waveform Generation mode. The design of the Output Compare pin logic allows initialization of the OC2A state before the output is enabled. Note that some COM2A1:0 bit settings are reserved for certain modes of operation. See “Register Description” on page 153. 17.6.1 Compare Output Mode and Waveform Generation The Waveform Generator uses the COM2A1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM2A1:0 = 0 tells the Waveform Generator that no action on the OC2A Register is to be performed on the next compare match. For compare output actions in the non-PWM modes refer to Table 17-3 on page 154. For fast PWM mode, refer to Table 17-4 on page 154, and for phase correct PWM refer to Table 17-5 on page 154. PORT DDR D Q D Q OCnx OCnx Pin D Q Waveform Generator COMnx1 COMnx0 0 1 DATA BUS FOCnx clkI/O145 2552K–AVR–04/11 ATmega329/3290/649/6490 A change of the COM2A1:0 bits state will have effect at the first compare match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC2A strobe bits. 17.7 Modes of Operation The mode of operation, i.e., the behavior of the Timer/Counter and the Output Compare pins, is defined by the combination of the Waveform Generation mode (WGM21:0) and Compare Output mode (COM2A1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM2A1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM2A1:0 bits control whether the output should be set, cleared, or toggled at a compare match (See “Compare Match Output Unit” on page 144.). For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 149. 17.7.1 Normal Mode The simplest mode of operation is the Normal mode (WGM21:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV2) will be set in the same timer clock cycle as the TCNT2 becomes zero. The TOV2 Flag in this case behaves like a ninth bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV2 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Output Compare unit can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 17.7.2 Clear Timer on Compare Match (CTC) Mode In Clear Timer on Compare or CTC mode (WGM21:0 = 2), the OCR2A Register is used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT2) matches the OCR2A. The OCR2A defines the top value for the counter, hence also its resolution. This mode allows greater control of the compare match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 17-5. The counter value (TCNT2) increases until a compare match occurs between TCNT2 and OCR2A, and then counter (TCNT2) is cleared.146 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 17-5. CTC Mode, Timing Diagram An interrupt can be generated each time the counter value reaches the TOP value by using the OCF2A Flag. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR2A is lower than the current value of TCNT2, the counter will miss the compare match. The counter will then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the compare match can occur. For generating a waveform output in CTC mode, the OC2A output can be set to toggle its logical level on each compare match by setting the Compare Output mode bits to toggle mode (COM2A1:0 = 1). The OC2A value will not be visible on the port pin unless the data direction for the pin is set to output. The waveform generated will have a maximum frequency of fOC2A = fclk_I/O/2 when OCR2A is set to zero (0x00). The waveform frequency is defined by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). As for the Normal mode of operation, the TOV2 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x00. 17.7.3 Fast PWM Mode The fast Pulse Width Modulation or fast PWM mode (WGM21:0 = 3) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM option by its single-slope operation. The counter counts from BOTTOM to MAX then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC2A) is cleared on the compare match between TCNT2 and OCR2A, and set at BOTTOM. In inverting Compare Output mode, the output is set on compare match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct PWM mode that uses dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), and therefore reduces total system cost. In fast PWM mode, the counter is incremented until the counter value matches the MAX value. The counter is then cleared at the following timer clock cycle. The timing diagram for the fast TCNTn OCnx (Toggle) OCnx Interrupt Flag Set Period 1 2 3 4 (COMnx1:0 = 1) f OCnx f clk_I/O 2 ⋅ ⋅ N ( ) 1 + OCRnx = -------------------------------------------------147 2552K–AVR–04/11 ATmega329/3290/649/6490 PWM mode is shown in Figure 17-6. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2A and TCNT2. Figure 17-6. Fast PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches MAX. If the interrupt is enabled, the interrupt handler routine can be used for updating the compare value. In fast PWM mode, the compare unit allows generation of PWM waveforms on the OC2A pin. Setting the COM2A1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM2A1:0 to three (See Table 17-4 on page 154). The actual OC2A value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by setting (or clearing) the OC2A Register at the compare match between OCR2A and TCNT2, and clearing (or setting) the OC2A Register at the timer clock cycle the counter is cleared (changes from MAX to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2A Register represent special cases when generating a PWM waveform output in the fast PWM mode. If the OCR2A is set equal to BOTTOM, the output will be a narrow spike for each MAX+1 timer clock cycle. Setting the OCR2A equal to MAX will result in a constantly high or low output (depending on the polarity of the output set by the COM2A1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC2A to toggle its logical level on each compare match (COM2A1:0 = 1). The waveform generated will have a maximum frequency of foc2 = fclk_I/O/2 when OCR2A is set to zero. This feature is similar to the OC2A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. TCNTn OCRnx Update and TOVn Interrupt Flag Set Period 1 2 3 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx Interrupt Flag Set 4 5 6 7 f OCnxPWM f clk_I/O N ⋅ 256 = ------------------148 2552K–AVR–04/11 ATmega329/3290/649/6490 17.7.4 Phase Correct PWM Mode The phase correct PWM mode (WGM21:0 = 1) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is based on a dual-slope operation. The counter counts repeatedly from BOTTOM to MAX and then from MAX to BOTTOM. In noninverting Compare Output mode, the Output Compare (OC2A) is cleared on the compare match between TCNT2 and OCR2A while counting up, and set on the compare match while counting down. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode is fixed to eight bits. In phase correct PWM mode the counter is incremented until the counter value matches MAX. When the counter reaches MAX, it changes the count direction. The TCNT2 value will be equal to MAX for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 17-7. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2A and TCNT2. Figure 17-7. Phase Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches BOTTOM. The Interrupt Flag can be used to generate an interrupt each time the counter reaches the BOTTOM value. In phase correct PWM mode, the compare unit allows generation of PWM waveforms on the OC2A pin. Setting the COM2A1:0 bits to two will produce a non-inverted PWM. An inverted PWM output can be generated by setting the COM2A1:0 to three (See Table 17-5 on page 154). The actual OC2A value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by clearing (or setting) the OC2A Register at the compare match between OCR2A and TCNT2 when the counter increments, and setting (or clearing) the OC2A Register at compare match between OCR2A and TCNT2 when the counter TOVn Interrupt Flag Set OCnx Interrupt Flag Set 1 2 3 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx Update149 2552K–AVR–04/11 ATmega329/3290/649/6490 decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2A Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR2A is set equal to BOTTOM, the output will be continuously low and if set equal to MAX the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. At the very start of period 2 in Figure 17-7 OCn has a transition from high to low even though there is no Compare Match. The point of this transition is to guarantee symmetry around BOTTOM. There are two cases that give a transition without Compare Match. • OCR2A changes its value from MAX, like in Figure 17-7. When the OCR2A value is MAX the OCn pin value is the same as the result of a down-counting compare match. To ensure symmetry around BOTTOM the OCn value at MAX must correspond to the result of an upcounting Compare Match. • The timer starts counting from a value higher than the one in OCR2A, and for that reason misses the Compare Match and hence the OCn change that would have happened on the way up. 17.8 Timer/Counter Timing Diagrams The following figures show the Timer/Counter in synchronous mode, and the timer clock (clkT2) is therefore shown as a clock enable signal. In asynchronous mode, clkI/O should be replaced by the Timer/Counter Oscillator clock. The figures include information on when Interrupt Flags are set. Figure 17-8 contains timing data for basic Timer/Counter operation. The figure shows the count sequence close to the MAX value in all modes other than phase correct PWM mode. Figure 17-8. Timer/Counter Timing Diagram, no Prescaling Figure 17-9 shows the same timing data, but with the prescaler enabled. f OCnxPCPWM f clk_I/O N ⋅ 510 = ------------------ clkTn (clkI/O/1) TOVn clkI/O TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1150 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 17-9. Timer/Counter Timing Diagram, with Prescaler (fclk_I/O/8) Figure 17-10 shows the setting of OCF2A in all modes except CTC mode. Figure 17-10. Timer/Counter Timing Diagram, Setting of OCF2A, with Prescaler (fclk_I/O/8) Figure 17-11 shows the setting of OCF2A and the clearing of TCNT2 in CTC mode. Figure 17-11. Timer/Counter Timing Diagram, Clear Timer on Compare Match mode, with Prescaler (fclk_I/O/8) TOVn TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn (CTC) TOP TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8)151 2552K–AVR–04/11 ATmega329/3290/649/6490 17.9 Asynchronous Operation of Timer/Counter2 When Timer/Counter2 operates asynchronously, some considerations must be taken. • Warning: When switching between asynchronous and synchronous clocking of Timer/Counter2, the Timer Registers TCNT2, OCR2A, and TCCR2A might be corrupted. A safe procedure for switching clock source is: 1. Disable the Timer/Counter2 interrupts by clearing OCIE2A and TOIE2. 2. Select clock source by setting AS2 as appropriate. 3. Write new values to TCNT2, OCR2A, and TCCR2A. 4. To switch to asynchronous operation: Wait for TCN2UB, OCR2UB, and TCR2UB. 5. Clear the Timer/Counter2 Interrupt Flags. 6. Enable interrupts, if needed. • The CPU main clock frequency must be more than four times the Oscillator frequency. • When writing to one of the registers TCNT2, OCR2A, or TCCR2A, the value is transferred to a temporary register, and latched after two positive edges on TOSC1. The user should not write a new value before the contents of the temporary register have been transferred to its destination. Each of the three mentioned registers have their individual temporary register, which means that e.g. writing to TCNT2 does not disturb an OCR2A write in progress. To detect that a transfer to the destination register has taken place, the Asynchronous Status Register – ASSR has been implemented. • When entering Power-save or ADC Noise Reduction mode after having written to TCNT2, OCR2A, or TCCR2A, the user must wait until the written register has been updated if Timer/Counter2 is used to wake up the device. Otherwise, the MCU will enter sleep mode before the changes are effective. This is particularly important if the Output Compare2 interrupt is used to wake up the device, since the Output Compare function is disabled during writing to OCR2A or TCNT2. If the write cycle is not finished, and the MCU enters sleep mode before the OCR2UB bit returns to zero, the device will never receive a compare match interrupt, and the MCU will not wake up. • If Timer/Counter2 is used to wake the device up from Power-save or ADC Noise Reduction mode, precautions must be taken if the user wants to re-enter one of these modes: The interrupt logic needs one TOSC1 cycle to be reset. If the time between wake-up and reentering sleep mode is less than one TOSC1 cycle, the interrupt will not occur, and the device will fail to wake up. If the user is in doubt whether the time before re-entering Powersave or ADC Noise Reduction mode is sufficient, the following algorithm can be used to ensure that one TOSC1 cycle has elapsed: 1. Write a value to TCCR2A, TCNT2, or OCR2A. 2. Wait until the corresponding Update Busy Flag in ASSR returns to zero. 3. Enter Power-save or ADC Noise Reduction mode. • When the asynchronous operation is selected, the 32.768kHz Oscillator for Timer/Counter2 is always running, except in Power-down and Standby modes. After a Power-up Reset or wake-up from Power-down or Standby mode, the user should be aware of the fact that this Oscillator might take as long as one second to stabilize. The user is advised to wait for at least one second before using Timer/Counter2 after power-up or wake-up from Power-down or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after a wake-up from Power-down or Standby mode due to unstable clock signal upon startup, no matter whether the Oscillator is in use or a clock signal is applied to the TOSC1 pin. • Description of wake up from Power-save or ADC Noise Reduction mode when the timer is clocked asynchronously: When the interrupt condition is met, the wake up process is started on the following cycle of the timer clock, that is, the timer is always advanced by at least one before the processor can read the counter value. After wake-up, the MCU is halted for four 152 2552K–AVR–04/11 ATmega329/3290/649/6490 cycles, it executes the interrupt routine, and resumes execution from the instruction following SLEEP. • Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect result. Since TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be done through a register synchronized to the internal I/O clock domain. Synchronization takes place for every rising TOSC1 edge. When waking up from Powersave mode, and the I/O clock (clkI/O) again becomes active, TCNT2 will read as the previous value (before entering sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after waking up from Power-save mode is essentially unpredictable, as it depends on the wake-up time. The recommended procedure for reading TCNT2 is thus as follows: 1. Write any value to either of the registers OCR2A or TCCR2A. 2. Wait for the corresponding Update Busy Flag to be cleared. 3. Read TCNT2. During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous timer takes 3 processor cycles plus one timer cycle. The timer is therefore advanced by at least one before the processor can read the timer value causing the setting of the Interrupt Flag. The Output Compare pin is changed on the timer clock and is not synchronized to the processor clock. 17.10 Timer/Counter Prescaler Figure 17-12. Prescaler for Timer/Counter2 The clock source for Timer/Counter2 is named clkT2S. clkT2S is by default connected to the main system I/O clock clkIO. By setting the AS2 bit in ASSR, Timer/Counter2 is asynchronously clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real Time Counter (RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from Port C. A crystal can then be connected between the TOSC1 and TOSC2 pins to serve as an independent clock source for Timer/Counter2. The Oscillator is optimized for use with a 32.768kHz crystal. If applying an external clock on TOSC1, the EXCLK bit in ASSR must be set. 10-BIT T/C PRESCALER TIMER/COUNTER2 CLOCK SOURCE clkI/O clkT2S TOSC1 AS2 CS20 CS21 CS22 clkT2S/8 clkT2S/64 clkT2S/128 clkT2S/1024 clkT2S/256 clkT2S/32 0 PSR2 Clear clkT2153 2552K–AVR–04/11 ATmega329/3290/649/6490 For Timer/Counter2, the possible prescaled selections are: clkT2S/8, clkT2S/32, clkT2S/64, clkT2S/128, clkT2S/256, and clkT2S/1024. Additionally, clkT2S as well as 0 (stop) may be selected. Setting the PSR2 bit in GTCCR resets the prescaler. This allows the user to operate with a predictable prescaler. 17.11 Register Description 17.11.1 TCCR2A – Timer/Counter Control Register A • Bit 7 – FOC2A: Force Output Compare A The FOC2A bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2A is written when operating in PWM mode. When writing a logical one to the FOC2A bit, an immediate compare match is forced on the Waveform Generation unit. The OC2A output is changed according to its COM2A1:0 bits setting. Note that the FOC2A bit is implemented as a strobe. Therefore it is the value present in the COM2A1:0 bits that determines the effect of the forced compare. A FOC2A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2A as TOP. The FOC2A bit is always read as zero. • Bit 6, 3 – WGM21:0: Waveform Generation Mode These bits control the counting sequence of the counter, the source for the maximum (TOP) counter value, and what type of waveform generation to be used. Modes of operation supported by the Timer/Counter unit are: Normal mode, Clear Timer on Compare match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes. See Table 17-2 and “Modes of Operation” on page 145. Note: 1. The CTC2 and PWM2 bit definition names are now obsolete. Use the WGM21:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer. • Bit 5:4 – COM2A1:0: Compare Match Output Mode A These bits control the Output Compare pin (OC2A) behavior. If one or both of the COM2A1:0 bits are set, the OC2A output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to OC2A pin must be set in order to enable the output driver. Bit 7 6 5 4 3 2 1 0 (0xB0) FOC2A WGM20 COM2A1 COM2A0 WGM21 CS22 CS21 CS20 TCCR2A Read/Write W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 17-2. Waveform Generation Mode Bit Description(1) Mode WGM21 (CTC2) WGM20 (PWM2) Timer/Counter Mode of Operation TOP Update of OCR2A at TOV2 Flag Set on 00 0 Normal 0xFF Immediate MAX 1 0 1 PWM, Phase Correct 0xFF TOP BOTTOM 2 1 0 CTC OCR2A Immediate MAX 3 1 1 Fast PWM 0xFF BOTTOM MAX154 2552K–AVR–04/11 ATmega329/3290/649/6490 When OC2A is connected to the pin, the function of the COM2A1:0 bits depends on the WGM21:0 bit setting. Table 17-3 shows the COM2A1:0 bit functionality when the WGM21:0 bits are set to a normal or CTC mode (non-PWM). Table 17-4 shows the COM2A1:0 bit functionality when the WGM21:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the compare match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on page 146 for more details. Table 17-5 shows the COM21:0 bit functionality when the WGM21:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the compare match is ignored, but the set or clear is done at TOP. See “Phase Correct PWM Mode” on page 148 for more details. Table 17-3. Compare Output Mode, non-PWM Mode COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected. 0 1 Toggle OC2A on compare match. 1 0 Clear OC2A on compare match. 1 1 Set OC2A on compare match. Table 17-4. Compare Output Mode, Fast PWM Mode(1) COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected. 0 1 Reserved 1 0 Clear OC2A on compare match, set OC2A at BOTTOM, (non-inverting mode). 1 1 Set OC2A on compare match, clear OC2A at BOTTOM, (inverting mode) Table 17-5. Compare Output Mode, Phase Correct PWM Mode(1) COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected. 0 1 Reserved 1 0 Clear OC2A on compare match when up-counting. Set OC2A on compare match when counting down. 1 1 Set OC2A on compare match when up-counting. Clear OC2A on compare match when counting down.155 2552K–AVR–04/11 ATmega329/3290/649/6490 • Bit 2:0 – CS22:0: Clock Select The three Clock Select bits select the clock source to be used by the Timer/Counter, see Table 17-6. 17.11.2 TCNT2 – Timer/Counter Register The Timer/Counter Register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the compare match on the following timer clock. Modifying the counter (TCNT2) while the counter is running, introduces a risk of missing a compare match between TCNT2 and the OCR2A Register. 17.11.3 OCR2A – Output Compare Register A The Output Compare Register A contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2A pin. 17.11.4 ASSR – Asynchronous Status Register • Bit 4 – EXCLK: Enable External Clock Input When EXCLK is written to one, and asynchronous clock is selected, the external clock input buffer is enabled and an external clock can be input on Timer Oscillator 1 (TOSC1) pin instead of a 32kHz crystal. Writing to EXCLK should be done before asynchronous operation is selected. Note that the crystal Oscillator will only run when this bit is zero. Table 17-6. Clock Select Bit Description CS22 CS21 CS20 Description 000 No clock source (Timer/Counter stopped). 0 0 1 clkT2S/(No prescaling) 0 1 0 clkT2S/8 (From prescaler) 0 1 1 clkT2S/32 (From prescaler) 1 0 0 clkT2S/64 (From prescaler) 1 0 1 clkT2S/128 (From prescaler) 1 1 0 clkT2S/256 (From prescaler) 1 1 1 clkT2S/1024 (From prescaler) Bit 7 6 5 4 3 2 1 0 (0xB2) TCNT2[7:0] TCNT2 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0xB3) OCR2A[7:0] OCR2A Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0xB6) – – – EXCLK AS2 TCN2UB OCR2UB TCR2UB ASSR Read/Write R R R R/W R/W R R R Initial Value 0 0 0 0 0 0 0 0156 2552K–AVR–04/11 ATmega329/3290/649/6490 • Bit 3 – AS2: Asynchronous Timer/Counter2 When AS2 is written to zero, Timer/Counter2 is clocked from the I/O clock, clkI/O. When AS2 is written to one, Timer/Counter2 is clocked from a crystal Oscillator connected to the Timer Oscillator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of TCNT2, OCR2A, and TCCR2A might be corrupted. • Bit 2 – TCN2UB: Timer/Counter2 Update Busy When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set. When TCNT2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value. • Bit 1 – OCR2UB: Output Compare Register2 Update Busy When Timer/Counter2 operates asynchronously and OCR2A is written, this bit becomes set. When OCR2A has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2A is ready to be updated with a new value. • Bit 0 – TCR2UB: Timer/Counter Control Register2 Update Busy When Timer/Counter2 operates asynchronously and TCCR2A is written, this bit becomes set. When TCCR2A has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2A is ready to be updated with a new value. If a write is performed to any of the three Timer/Counter2 Registers while its update busy flag is set, the updated value might get corrupted and cause an unintentional interrupt to occur. The mechanisms for reading TCNT2, OCR2A, and TCCR2A are different. When reading TCNT2, the actual timer value is read. When reading OCR2A or TCCR2A, the value in the temporary storage register is read. 17.11.5 TIMSK2 – Timer/Counter2 Interrupt Mask Register • Bit 1 – OCIE2A: Timer/Counter2 Output Compare Match A Interrupt Enable When the OCIE2A bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match A interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, i.e., when the OCF2A bit is set in the Timer/Counter 2 Interrupt Flag Register – TIFR2. • Bit 0 – TOIE2: Timer/Counter2 Overflow Interrupt Enable When the TOIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter2 occurs, i.e., when the TOV2 bit is set in the Timer/Counter2 Interrupt Flag Register – TIFR2. Bit 7 6 5 4 3 2 1 0 (0x70) – – – – – – OCIE2A TOIE2 TIMSK2 Read/Write R R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0157 2552K–AVR–04/11 ATmega329/3290/649/6490 17.11.6 TIFR2 – Timer/Counter2 Interrupt Flag Register • Bit 1 – OCF2A: Output Compare Flag 2 A The OCF2A bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2A – Output Compare Register2. OCF2A is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF2A is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2A (Timer/Counter2 Compare match Interrupt Enable), and OCF2A are set (one), the Timer/Counter2 Compare match Interrupt is executed. • Bit 0 – TOV2: Timer/Counter2 Overflow Flag The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV2 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE2A (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter2 changes counting direction at 0x00. 17.11.7 GTCCR – General Timer/Counter Control Register • Bit 1 – PSR2: Prescaler Reset Timer/Counter2 When this bit is one, the Timer/Counter2 prescaler will be reset. This bit is normally cleared immediately by hardware. If the bit is written when Timer/Counter2 is operating in asynchronous mode, the bit will remain one until the prescaler has been reset. The bit will not be cleared by hardware if the TSM bit is set. Refer to the description of the “Bit 7 – TSM: Timer/Counter Synchronization Mode” on page 108 for a description of the Timer/Counter Synchronization mode. Bit 7 6 5 4 3 2 1 0 0x17 (0x37) – – – – – – OCF2A TOV2 TIFR2 Read/Write R R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x23 (0x43) TSM – – – – – PSR2 PSR10 GTCCR Read/Write R/W R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0158 2552K–AVR–04/11 ATmega329/3290/649/6490 18. SPI – Serial Peripheral Interface 18.1 Features The ATmega329/3290/649/6490 SPI includes the following features: • Full-duplex, Three-wire Synchronous Data Transfer • Master or Slave Operation • LSB First or MSB First Data Transfer • Seven Programmable Bit Rates • End of Transmission Interrupt Flag • Write Collision Flag Protection • Wake-up from Idle Mode • Double Speed (CK/2) Master SPI Mode 18.2 Overview The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the ATmega329/3290/649/6490 and peripheral devices or between several AVR devices. A simplified block diagram of the Serial Peripheral Interface is shown in Figure 18-1. The PRSPI bit in “Power Reduction Register” on page 37 must be written to zero to enable the SPI module. Figure 18-1. SPI Block Diagram(1) Note: 1. Refer to Figure 1-1 on page 2, and Table 13-6 on page 68 for SPI pin placement. SPI2X SPI2X DIVIDER /2/4/8/16/32/64/128159 2552K–AVR–04/11 ATmega329/3290/649/6490 The interconnection between Master and Slave CPUs with SPI is shown in Figure 18-2. The system consists of two shift Registers, and a Master clock generator. The SPI Master initiates the communication cycle when pulling low the Slave Select SS pin of the desired Slave. Master and Slave prepare the data to be sent in their respective shift Registers, and the Master generates the required clock pulses on the SCK line to interchange data. Data is always shifted from Master to Slave on the Master Out – Slave In, MOSI, line, and from Slave to Master on the Master In – Slave Out, MISO, line. After each data packet, the Master will synchronize the Slave by pulling high the Slave Select, SS, line. When configured as a Master, the SPI interface has no automatic control of the SS line. This must be handled by user software before communication can start. When this is done, writing a byte to the SPI Data Register starts the SPI clock generator, and the hardware shifts the eight bits into the Slave. After shifting one byte, the SPI clock generator stops, setting the end of Transmission Flag (SPIF). If the SPI Interrupt Enable bit (SPIE) in the SPCR Register is set, an interrupt is requested. The Master may continue to shift the next byte by writing it into SPDR, or signal the end of packet by pulling high the Slave Select, SS line. The last incoming byte will be kept in the Buffer Register for later use. When configured as a Slave, the SPI interface will remain sleeping with MISO tri-stated as long as the SS pin is driven high. In this state, software may update the contents of the SPI Data Register, SPDR, but the data will not be shifted out by incoming clock pulses on the SCK pin until the SS pin is driven low. As one byte has been completely shifted, the end of Transmission Flag, SPIF is set. If the SPI Interrupt Enable bit, SPIE, in the SPCR Register is set, an interrupt is requested. The Slave may continue to place new data to be sent into SPDR before reading the incoming data. The last incoming byte will be kept in the Buffer Register for later use. Figure 18-2. SPI Master-slave Interconnection The system is single buffered in the transmit direction and double buffered in the receive direction. This means that bytes to be transmitted cannot be written to the SPI Data Register before the entire shift cycle is completed. When receiving data, however, a received character must be read from the SPI Data Register before the next character has been completely shifted in. Otherwise, the first byte is lost. In SPI Slave mode, the control logic will sample the incoming signal of the SCK pin. To ensure correct sampling of the clock signal, the minimum low and high period should be: Low period: longer than 2 CPU clock cycles. High period: longer than 2 CPU clock cycles. SHIFT ENABLE160 2552K–AVR–04/11 ATmega329/3290/649/6490 When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden according to Table 18-1. For more details on automatic port overrides, refer to “Alternate Port Functions” on page 65. Note: 1. See “Alternate Functions of Port B” on page 68 for a detailed description of how to define the direction of the user defined SPI pins. Table 18-1. SPI Pin Overrides(1) Pin Direction, Master SPI Direction, Slave SPI MOSI User Defined Input MISO Input User Defined SCK User Defined Input SS User Defined Input161 2552K–AVR–04/11 ATmega329/3290/649/6490 The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. E.g. if MOSI is placed on pin PB5, replace DD_MOSI with DDB5 and DDR_SPI with DDRB. Note: 1. See “About Code Examples” on page 9. Assembly Code Example(1) SPI_MasterInit: ; Set MOSI and SCK output, all others input ldi r17,(1<>8); UBRR0L = (unsigned char)ubrr; /* Enable receiver and transmitter */ UCSR0B = (1<> 1) & 0x01; return ((resh << 8) | resl); }180 2552K–AVR–04/11 ATmega329/3290/649/6490 19.7.3 Receive Compete Flag and Interrupt The USART Receiver has one flag that indicates the Receiver state. The Receive Complete (RXCn) Flag indicates if there are unread data present in the receive buffer. This flag is one when unread data exist in the receive buffer, and zero when the receive buffer is empty (i.e., does not contain any unread data). If the Receiver is disabled (RXENn = 0), the receive buffer will be flushed and consequently the RXCn bit will become zero. When the Receive Complete Interrupt Enable (RXCIEn) in UCSRnB is set, the USART Receive Complete interrupt will be executed as long as the RXCn Flag is set (provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDRn in order to clear the RXCn Flag, otherwise a new interrupt will occur once the interrupt routine terminates. 19.7.4 Receiver Error Flags The USART Receiver has three Error Flags: Frame Error (FEn), Data OverRun (DORn) and Parity Error (UPEn). All can be accessed by reading UCSRnA. Common for the Error Flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the Error Flags, the UCSRnA must be read before the receive buffer (UDRn), since reading the UDRn I/O location changes the buffer read location. Another equality for the Error Flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRnA is written for upward compatibility of future USART implementations. None of the Error Flags can generate interrupts. The Frame Error (FEn) Flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FEn Flag is zero when the stop bit was correctly read (as one), and the FEn Flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FEn Flag is not affected by the setting of the USBSn bit in UCSRnC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. The Data OverRun (DORn) Flag indicates data loss due to a receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DORn Flag is set there was one or more serial frame lost between the frame last read from UDRn, and the next frame read from UDRn. For compatibility with future devices, always write this bit to zero when writing to UCSRnA. The DORn Flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (UPEn) Flag indicates that the next frame in the receive buffer had a Parity Error when received. If Parity Check is not enabled the UPEn bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. For more details see “Parity Bit Calculation” on page 173 and “Parity Checker” on page 180. 19.7.5 Parity Checker The Parity Checker is active when the high USART Parity mode (UPMn1) bit is set. Type of Parity Check to be performed (odd or even) is selected by the UPMn0 bit. When enabled, the Parity Checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error (UPEn) Flag can then be read by software to check if the frame had a Parity Error.181 2552K–AVR–04/11 ATmega329/3290/649/6490 The UPEn bit is set if the next character that can be read from the receive buffer had a Parity Error when received and the Parity Checking was enabled at that point (UPMn1 = 1). This bit is valid until the receive buffer (UDRn) is read. 19.7.6 Disabling the Receiver In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing receptions will therefore be lost. When disabled (i.e., the RXENn is set to zero) the Receiver will no longer override the normal function of the RxD port pin. The Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in the buffer will be lost 19.7.7 Flushing the Receive Buffer The receiver buffer FIFO will be flushed when the Receiver is disabled, i.e., the buffer will be emptied of its contents. Unread data will be lost. If the buffer has to be flushed during normal operation, due to for instance an error condition, read the UDRn I/O location until the RXCn Flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See “About Code Examples” on page 9. 19.8 Asynchronous Data Reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxD pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the Receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. 19.8.1 Asynchronous Clock Recovery The clock recovery logic synchronizes internal clock to the incoming serial frames. Figure 19-5 illustrates the sampling process of the start bit of an incoming frame. The sample rate is 16 times the baud rate for Normal mode, and eight times the baud rate for Double Speed mode. The horizontal arrows illustrate the synchronization variation due to the sampling process. Note the larger time variation when using the Double Speed mode (U2Xn = 1) of operation. Samples denoted zero are samples done when the RxD line is idle (i.e., no communication activity). Assembly Code Example(1) USART_Flush: sbis UCSR0A, RXC0 ret in r16, UDR0 rjmp USART_Flush C Code Example(1) void USART_Flush( void ) { unsigned char dummy; while ( UCSR0A & (1< 470 nF) must be connected to the LCDCAP pin as shown in Figure 23-2. This capacitor acts as a reservoir for LCD power (VLCD). A large capacitance reduces ripple on VLCD but increases the time until VLCD reaches its target value. Figure 23-2. LCDCAP Connection 23.1.8 LCD Buffer Driver Intermediate voltage levels are generated from buffers/drivers. The buffers are active the amount of time specified by LCDDC[2:0] in LCDCCR. Then LCD output pins are tri-stated and buffers are switched off. Shortening the drive time will reduce power consumption, but displays with high internal resistance or capacitance may need longer drive time to achieve sufficient contrast. 23.1.9 Display requirements When using more than one common pin, the maximum period the LCD drivers can be turned on for each voltage transition on the LCD pins is 50% of the prescaled LCD clock period, clkLCD_PS. To avoid flickering, it is recommended to keep the framerate above 30Hz, thus giving a maximum drive time of approximately 2ms when using 1/2 or 1/4 duty, and approximately 2.7ms 1 2 3 64 63 62 LCDCAP231 2552K–AVR–04/11 ATmega329/3290/649/6490 when using 1/3 duty. To achieve satisfactory contrast, all segments on the LCD display must therefore be able to be fully charged/discharged within 2 or 2.7ms, depending on the number of common pins. 23.1.10 Minimizing power consumption By keeping the percentage of the time the LCD drivers are turned on at a minimum, the power consumption of the LCD driver can be minimized. This can be achieved by using the lowest acceptable frame rate, and using low power waveform if possible. The drive time should be kept at the lowest setting that achieves satisfactory contrast for a particular display, while allowing some headroom for production variations between individual LCD drivers and displays. Note that some of the highest LCD voltage settings may result in high power consumption when VCC is below 2.0V. The recommended maximum LCD voltage is 2*(VCC - 0.2V). 23.2 Mode of Operation 23.2.1 Static Duty and Bias If all segments on a LCD have one electrode common, then each segment must have a unique terminal. This kind of display is driven with the waveform shown in Figure 23-3. SEG0 - COM0 is the voltage across a segment that is on, and SEG1 - COM0 is the voltage across a segment that is off. Figure 23-3. Driving a LCD with One Common Terminal 23.2.2 1/2 Duty and 1/2 Bias For LCD with two common terminals (1/2 duty) a more complex waveform must be used to individually control segments. Although 1/3 bias can be selected 1/2 bias is most common for these displays. Waveform is shown in Figure 23-4. SEG0 - COM0 is the voltage across a segment that is on, and SEG0 - COM1 is the voltage across a segment that is off. VLCD GND VLCD GND VLCD GND -VLCD SEG0 COM0 SEG0 - COM0 Frame Frame VLCD GND VLCD GND GND SEG1 COM0 SEG1 - COM0 Frame Frame232 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 23-4. Driving a LCD with Two Common Terminals 23.2.3 1/3 Duty and 1/3 Bias 1/3 bias is usually recommended for LCD with three common terminals (1/3 duty). Waveform is shown in Figure 23-5. SEG0 - COM0 is the voltage across a segment that is on and SEG0- COM1 is the voltage across a segment that is off. Figure 23-5. Driving a LCD with Three Common Terminals 23.2.4 1/4 Duty and 1/3 Bias 1/3 bias is optimal for LCD displays with four common terminals (1/4 duty). Waveform is shown in Figure 23-6. SEG0 - COM0 is the voltage across a segment that is on and SEG0 - COM1 is the voltage across a segment that is off. VLCD GND VLCD 1/ 2VLCD GND VLCD 1/ 2VLCD GND -1/ 2VLCD -VLCD SEG0 COM0 SEG0 - COM0 Frame Frame VLCD GND VLCD 1/ 2VLCD GND VLCD 1/ 2VLCD GND -1/ 2VLCD -VLCD SEG0 COM1 SEG0 - COM1 Frame Frame VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND -1/ 3VLCD -2/ 3VLCD -VLCD SEG0 COM0 SEG0 - COM0 Frame Frame VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND -1/ 3VLCD -2/ 3VLCD -VLCD SEG0 COM1 SEG0 - COM1 Frame Frame233 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 23-6. Driving a LCD with Four Common Terminals 23.2.5 Low Power Waveform To reduce toggle activity and hence power consumption a low power waveform can be selected by writing LCDAB to one. Low power waveform requires two subsequent frames with the same display data to obtain zero DC voltage. Consequently data latching and Interrupt Flag is only set every second frame. Default and low power waveform is shown in Figure 23-7 for 1/3 duty and 1/3 bias. For other selections of duty and bias, the effect is similar. Figure 23-7. Default and Low Power Waveform 23.2.6 Operation in Sleep Mode When synchronous LCD clock is selected (LCDCS = 0) the LCD display will operate in Idle mode and Power-save mode with any clock source. An asynchronous clock from TOSC1 can be selected as LCD clock by writing the LCDCS bit to one when Calibrated Internal RC Oscillator is selected as system clock source. The LCD will then operate in Idle mode, ADC Noise Reduction mode and Power-save mode. VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND -1/ 3VLCD -2/ 3VLCD -VLCD SEG0 COM0 SEG0 - COM0 Frame Frame VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND -1/ 3VLCD -2/ 3VLCD -VLCD SEG0 COM1 SEG0 - COM1 Frame Frame VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND -1/ 3VLCD -2/ 3VLCD -VLCD SEG0 COM0 SEG0 - COM0 Frame Frame VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND VLCD 2/ 3VLCD 1/ 3VLCD GND -1/ 3VLCD -2/ 3VLCD -VLCD SEG0 COM0 SEG0 - COM0 Frame Frame234 2552K–AVR–04/11 ATmega329/3290/649/6490 When EXCLK in ASSR Register is written to one, and asynchronous clock is selected, the external clock input buffer is enabled and an external clock can be input on Timer Oscillator 1 (TOSC1) pin instead of a 32kHz crystal. See “Asynchronous Operation of Timer/Counter2” on page 151 for further details. Before entering Power-down mode, Standby mode or ADC Noise Reduction mode with synchronous LCD clock selected, the user have to disable the LCD. Refer to “Disabling the LCD” on page 237. 23.2.7 Display Blanking When LCDBL is written to one, the LCD is blanked after completing the current frame. All segments and common pins are connected to GND, discharging the LCD. Display memory is preserved. Display blanking should be used before disabling the LCD to avoid DC voltage across segments, and a slowly fading image. 23.2.8 Port Mask For LCD with less than 25/40 segment terminals, it is possible to mask some of the unused pins and use them as ordinary port pins instead. Refer to Table 23-3 for details. Unused common pins are automatically configured as port pins.235 2552K–AVR–04/11 ATmega329/3290/649/6490 23.3 LCD Usage The following section describes how to use the LCD. 23.3.1 LCD Initialization Prior to enabling the LCD some initialization must be preformed. The initialization process normally consists of setting the frame rate, duty, bias and port mask. LCD contrast is set initially, but can also be adjusted during operation. Consider the following LCD as an example: Figure 23-8. Display: TN Positive, Reflective Number of common terminals: 3 Number of segment terminals: 21 Bias system: 1/3 Bias Drive system: 1/3 Duty Operating voltage: 3.0 ± 0.3 V 1b 1c 2a 2b 2e 2c 2f 2d 2g COM3 COM0 COM1 COM2 SEG0 SEG1 SEG2 1b,1c 2c 2f 2a 2d 2g 2b 2e .. COM2 SEG0 SEG1 SEG2 ATmega329 COM0 COM1 Connection table LCD 51 50 49 48 47 46 45236 2552K–AVR–04/11 ATmega329/3290/649/6490 Note: 1. See “About Code Examples” on page 9. Before a re-initialization is done, the LCD controller/driver should be disabled Assembly Code Example(1) LCD_Init: ; Use 32 kHz crystal oscillator ; 1/3 Bias and 1/3 duty, SEG21:SEG24 is used as port pins ldi r16, (1< 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck ≥ 12MHz High: > 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck ≥ 12MHz 27.7.2 Serial Programming Algorithm When writing serial data to the ATmega329/3290/649/6490, data is clocked on the rising edge of SCK. When reading data from the ATmega329/3290/649/6490, data is clocked on the falling edge of SCK. See Figure 27-11 for timing details. To program and verify the ATmega329/3290/649/6490 in the serial programming mode, the following sequence is recommended (See four byte instruction formats in Table 27-15): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to “0”. In some systems, the programmer can not guarantee that SCK is held low during power-up. In this case, RESET must be given a positive pulse of at least two CPU clock cycles duration after SCK has been set to “0”. 2. Wait for at least 20ms and enable serial programming by sending the Programming Enable serial instruction to pin MOSI. 3. The serial programming instructions will not work if the communication is out of synchronization. When in sync. the second byte (0x53), will echo back when issuing the third byte of the Programming Enable instruction. Whether the echo is correct or not, all four bytes of the instruction must be transmitted. If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command. 4. The Flash is programmed one page at a time. The page size is found in Table 27-10 on page 298. The memory page is loaded one byte at a time by supplying the 6/7 LSB of the address and data together with the Load Program Memory Page instruction. To ensure correct loading of the page, the data low byte must be loaded before data high byte is applied for a given address. The Program Memory Page is stored by loading the Write Program Memory Page instruction with the 8 MSB of the address. If polling is not used, the user must wait at least tWD_FLASH before issuing the next page. (See Table 27-14.) Accessing the serial programming interface before the Flash write operation completes can result in incorrect programming. 5. A: The EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. If polling (RDY/BSY) is not used, the user must wait at least tWD_EEPROM before issuing the next byte (See Table 27-14.) In a chip erased device, no 0xFFs in the data file(s) need to be programmed. B: The EEPROM array is programmed one page at a time. The Memory page is loaded one byte at a time by supplying the 2 LSB of the address and data together with the Load EEPROM Memory Page instruction. The EEPROM Memory Page is stored by loading the Write EEPROM Memory Page Instruction with the 4 MSB of the address. When using EEPROM page access only byte locations loaded with the Load EEPROM Memory Page instruction is altered. The remaining locations remain unchanged. If polling (RDY/BSY) is not used, the used must wait at least tWD_EEPROM before issuing the next page (See Table 27-11). In a chip erased device, no 0xFF in the data file(s) need to be programmed. 6. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO. 7. At the end of the programming session, RESET can be set high to commence normal operation.310 2552K–AVR–04/11 ATmega329/3290/649/6490 8. Power-off sequence (if needed): Set RESET to “1”. Turn VCC power off. Figure 27-11. Serial Programming Waveforms 27.7.3 Serial Programming Instruction set Table 27-15 and Figure 27-12 on page 312 describes the Instruction set. Table 27-14. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location Symbol Minimum Wait Delay tWD_FUSE 4.5ms tWD_FLASH 4.5ms tWD_EEPROM 9.0ms tWD_ERASE 9.0ms MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUT Table 27-15. Serial Programming Instruction Set Instruction/Operation Instruction Format Byte 1 Byte 2 Byte 3 Byte4 Programming Enable $AC $53 $00 $00 Chip Erase (Program Memory/EEPROM) $AC $80 $00 $00 Poll RDY/BSY $F0 $00 $00 data byte out Load Instructions Load Extended Address byte(1) $4D $00 Extended adr $00 Load Program Memory Page, High byte $48 $00 adr LSB high data byte in Load Program Memory Page, Low byte $40 $00 adr LSB low data byte in Load EEPROM Memory Page (page access) $C1 $00 0000 00aa / 0000 0aaa data byte in Read Instructions Read Program Memory, High byte $28 adr MSB adr LSB high data byte out Read Program Memory, Low byte $20 adr MSB adr LSB low data byte out Read EEPROM Memory $A0 0000 00aa / 0000 0aaa aaaa aaaa data byte out311 2552K–AVR–04/11 ATmega329/3290/649/6490 Note: 1. Not all instructions are applicable for all parts 2. a = address 3. Bits are programmed ‘0’, unprogrammed ‘1’. 4. To ensure future compatibility, unused Fuses and Lock bits should be unprogrammed (‘1’) . 5. Refer to the correspondig section for Fuse and Lock bits, Calibration and Signature bytes and Page size. 6. See htt://www.atmel.com/avr for Application Notes regarding programming and programmers. If the LSB in RDY/BSY data byte out is ‘1’, a programming operation is still pending. Wait until this bit returns ‘0’ before the next instruction is carried out. Within the same page, the low data byte must be loaded prior to the high data byte. After data is loaded to the page buffer, program the EEPROM page, see Figure 27-12. Read Lock bits $58 $00 $00 data byte out Read Signature Byte $30 $00 0000 000aa data byte out Read Fuse bits $50 $00 $00 data byte out Read Fuse High bits $58 $08 $00 data byte out Read Extended Fuse Bits $50 $08 $00 data byte out Read Calibration Byte $38 $00 $00 data byte out Write Instructions Write Program Memory Page $4C adr MSB adr LSB $00 Write EEPROM Memory $C0 0000 00aa / 0000 0aaa aaaa aaaa data byte in Write EEPROM Memory Page (page access) $C2 0000 00aa / 0000 0aaa aaaa aa00 / aaaa a000 $00 Write Lock bits $AC $E0 $00 data byte in Write Fuse bits $AC $A0 $00 data byte in Write Fuse High bits $AC $A8 $00 data byte in Write Extended Fuse Bits $AC $A4 $00 data byte in Table 27-15. Serial Programming Instruction Set Instruction/Operation Instruction Format Byte 1 Byte 2 Byte 3 Byte4312 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 27-12. Serial Programming Instruction example 27.7.4 SPI Serial Programming Characteristics For characteristics of the SPI module see “SPI Timing Characteristics” on page 331. Byte 1 Byte 2 Byte 3 Byte 4 Adr LSB Bit 15 B 0 Serial Programming Instruction Program Memory/ EEPROM Memory Page 0 Page 1 Page 2 Page N-1 Page Buffer Write Program Memory Page/ Write EEPROM Memory Page Load Program Memory Page (High/Low Byte)/ Load EEPROM Memory Page (page access) Byte 1 Byte 2 Byte 3 Byte 4 Bit 15 B 0 Adr MSB Page Offset Page Number Adr MSB Adr LSB313 2552K–AVR–04/11 ATmega329/3290/649/6490 27.8 Programming via the JTAG Interface Programming through the JTAG interface requires control of the four JTAG specific pins: TCK, TMS, TDI, and TDO. Control of the reset and clock pins is not required. To be able to use the JTAG interface, the JTAGEN Fuse must be programmed. The device is default shipped with the fuse programmed. In addition, the JTD bit in MCUCSR must be cleared. Alternatively, if the JTD bit is set, the external reset can be forced low. Then, the JTD bit will be cleared after two chip clocks, and the JTAG pins are available for programming. This provides a means of using the JTAG pins as normal port pins in Running mode while still allowing In-System Programming via the JTAG interface. Note that this technique can not be used when using the JTAG pins for Boundary-scan or On-chip Debug. In these cases the JTAG pins must be dedicated for this purpose. During programming the clock frequency of the TCK Input must be less than the maximum frequency of the chip. The System Clock Prescaler can not be used to divide the TCK Clock Input into a sufficiently low frequency. As a definition in this data sheet, the LSB is shifted in and out first of all Shift Registers. 27.8.1 Programming Specific JTAG Instructions The Instruction Register is 4-bit wide, supporting up to 16 instructions. The JTAG instructions useful for programming are listed below. The OPCODE for each instruction is shown behind the instruction name in hex format. The text describes which Data Register is selected as path between TDI and TDO for each instruction. The Run-Test/Idle state of the TAP controller is used to generate internal clocks. It can also be used as an idle state between JTAG sequences. The state machine sequence for changing the instruction word is shown in Figure 27-13.314 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 27-13. State Machine Sequence for Changing the Instruction Word 27.8.2 AVR_RESET (0xC) The AVR specific public JTAG instruction for setting the AVR device in the Reset mode or taking the device out from the Reset mode. The TAP controller is not reset by this instruction. The one bit Reset Register is selected as Data Register. Note that the reset will be active as long as there is a logic “one” in the Reset Chain. The output from this chain is not latched. The active states are: • Shift-DR: The Reset Register is shifted by the TCK input. 27.8.3 PROG_ENABLE (0x4) The AVR specific public JTAG instruction for enabling programming via the JTAG port. The 16- bit Programming Enable Register is selected as Data Register. The active states are the following: • Shift-DR: The programming enable signature is shifted into the Data Register. • Update-DR: The programming enable signature is compared to the correct value, and Programming mode is entered if the signature is valid. Test-Logic-Reset Run-Test/Idle Shift-DR Exit1-DR Pause-DR Exit2-DR Update-DR Select-IR Scan Capture-IR Shift-IR Exit1-IR Pause-IR Exit2-IR Update-IR Select-DR Scan Capture-DR 0 1 0 11 1 0 0 0 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 0 0 1 1315 2552K–AVR–04/11 ATmega329/3290/649/6490 27.8.4 PROG_COMMANDS (0x5) The AVR specific public JTAG instruction for entering programming commands via the JTAG port. The 15-bit Programming Command Register is selected as Data Register. The active states are the following: • Capture-DR: The result of the previous command is loaded into the Data Register. • Shift-DR: The Data Register is shifted by the TCK input, shifting out the result of the previous command and shifting in the new command. • Update-DR: The programming command is applied to the Flash inputs • Run-Test/Idle: One clock cycle is generated, executing the applied command (not always required, see Table 27-16 below). 27.8.5 PROG_PAGELOAD (0x6) The AVR specific public JTAG instruction to directly load the Flash data page via the JTAG port. An 8-bit Flash Data Byte Register is selected as the Data Register. This is physically the 8 LSBs of the Programming Command Register. The active states are the following: • Shift-DR: The Flash Data Byte Register is shifted by the TCK input. • Update-DR: The content of the Flash Data Byte Register is copied into a temporary register. A write sequence is initiated that within 11 TCK cycles loads the content of the temporary register into the Flash page buffer. The AVR automatically alternates between writing the low and the high byte for each new Update-DR state, starting with the low byte for the first Update-DR encountered after entering the PROG_PAGELOAD command. The Program Counter is pre-incremented before writing the low byte, except for the first written byte. This ensures that the first data is written to the address set up by PROG_COMMANDS, and loading the last location in the page buffer does not make the program counter increment into the next page. 27.8.6 PROG_PAGEREAD (0x7) The AVR specific public JTAG instruction to directly capture the Flash content via the JTAG port. An 8-bit Flash Data Byte Register is selected as the Data Register. This is physically the 8 LSBs of the Programming Command Register. The active states are the following: • Capture-DR: The content of the selected Flash byte is captured into the Flash Data Byte Register. The AVR automatically alternates between reading the low and the high byte for each new Capture-DR state, starting with the low byte for the first Capture-DR encountered after entering the PROG_PAGEREAD command. The Program Counter is post-incremented after reading each high byte, including the first read byte. This ensures that the first data is captured from the first address set up by PROG_COMMANDS, and reading the last location in the page makes the program counter increment into the next page. • Shift-DR: The Flash Data Byte Register is shifted by the TCK input. 27.8.7 Data Registers The Data Registers are selected by the JTAG instruction registers described in section “Programming Specific JTAG Instructions” on page 313. The Data Registers relevant for programming operations are: • Reset Register • Programming Enable Register • Programming Command Register • Flash Data Byte Register316 2552K–AVR–04/11 ATmega329/3290/649/6490 27.8.8 Reset Register The Reset Register is a Test Data Register used to reset the part during programming. It is required to reset the part before entering Programming mode. A high value in the Reset Register corresponds to pulling the external reset low. The part is reset as long as there is a high value present in the Reset Register. Depending on the Fuse settings for the clock options, the part will remain reset for a Reset Time-out period (refer to “Clock Sources” on page 27) after releasing the Reset Register. The output from this Data Register is not latched, so the reset will take place immediately, as shown in Figure 25-2 on page 253. 27.8.9 Programming Enable Register The Programming Enable Register is a 16-bit register. The contents of this register is compared to the programming enable signature, binary code 0b1010_0011_0111_0000. When the contents of the register is equal to the programming enable signature, programming via the JTAG port is enabled. The register is reset to 0 on Power-on Reset, and should always be reset when leaving Programming mode. Figure 27-14. Programming Enable Register 27.8.10 Programming Command Register The Programming Command Register is a 15-bit register. This register is used to serially shift in programming commands, and to serially shift out the result of the previous command, if any. The JTAG Programming Instruction Set is shown in Table 27-16. The state sequence when shifting in the programming commands is illustrated in Figure 27-16. TDI TDO D A T A = D Q ClockDR & PROG_ENABLE Programming Enable 0xA370317 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 27-15. Programming Command Register TDI TDO S T R O B E S A D D R E S S / D A T A Flash EEPROM Fuses Lock Bits318 2552K–AVR–04/11 ATmega329/3290/649/6490 Table 27-16. JTAG Programming Instruction Set a = address high bits, b = address low bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care Instruction TDI Sequence TDO Sequence Notes 1a. Chip Erase 0100011_10000000 0110001_10000000 0110011_10000000 0110011_10000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx 1b. Poll for Chip Erase Complete 0110011_10000000 xxxxxox_xxxxxxxx (2) 2a. Enter Flash Write 0100011_00010000 xxxxxxx_xxxxxxxx 2b. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx (9) 2c. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 2d. Load Data Low Byte 0010011_iiiiiiii xxxxxxx_xxxxxxxx 2e. Load Data High Byte 0010111_iiiiiiii xxxxxxx_xxxxxxxx 2f. Latch Data 0110111_00000000 1110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 2g. Write Flash Page 0110111_00000000 0110101_00000000 0110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 2h. Poll for Page Write Complete 0110111_00000000 xxxxxox_xxxxxxxx (2) 3a. Enter Flash Read 0100011_00000010 xxxxxxx_xxxxxxxx 3b. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx (9) 3c. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 3d. Read Data Low and High Byte 0110010_00000000 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo xxxxxxx_oooooooo Low byte High byte 4a. Enter EEPROM Write 0100011_00010001 xxxxxxx_xxxxxxxx 4b. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx (9) 4c. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 4d. Load Data Byte 0010011_iiiiiiii xxxxxxx_xxxxxxxx 4e. Latch Data 0110111_00000000 1110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 4f. Write EEPROM Page 0110011_00000000 0110001_00000000 0110011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 4g. Poll for Page Write Complete 0110011_00000000 xxxxxox_xxxxxxxx (2) 5a. Enter EEPROM Read 0100011_00000011 xxxxxxx_xxxxxxxx 5b. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx (9)319 2552K–AVR–04/11 ATmega329/3290/649/6490 5c. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 5d. Read Data Byte 0110011_bbbbbbbb 0110010_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 6a. Enter Fuse Write 0100011_01000000 xxxxxxx_xxxxxxxx 6b. Load Data Low Byte(6) 0010011_iiiiiiii xxxxxxx_xxxxxxxx (3) 6c. Write Fuse Extended Byte 0111011_00000000 0111001_00000000 0111011_00000000 0111011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 6d. Poll for Fuse Write Complete 0110111_00000000 xxxxxox_xxxxxxxx (2) 6e. Load Data Low Byte(7) 0010011_iiiiiiii xxxxxxx_xxxxxxxx (3) 6f. Write Fuse High Byte 0110111_00000000 0110101_00000000 0110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 6g. Poll for Fuse Write Complete 0110111_00000000 xxxxxox_xxxxxxxx (2) 6h. Load Data Low Byte(7) 0010011_iiiiiiii xxxxxxx_xxxxxxxx (3) 6i. Write Fuse Low Byte 0110011_00000000 0110001_00000000 0110011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 6j. Poll for Fuse Write Complete 0110011_00000000 xxxxxox_xxxxxxxx (2) 7a. Enter Lock Bit Write 0100011_00100000 xxxxxxx_xxxxxxxx 7b. Load Data Byte(9) 0010011_11iiiiii xxxxxxx_xxxxxxxx (4) 7c. Write Lock Bits 0110011_00000000 0110001_00000000 0110011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 7d. Poll for Lock Bit Write complete 0110011_00000000 xxxxxox_xxxxxxxx (2) 8a. Enter Fuse/Lock Bit Read 0100011_00000100 xxxxxxx_xxxxxxxx 8b. Read Extended Fuse Byte(6) 0111010_00000000 0111011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 8c. Read Fuse High Byte(7) 0111110_00000000 0111111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 8d. Read Fuse Low Byte(8) 0110010_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 8e. Read Lock Bits(9) 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxoooooo (5) Table 27-16. JTAG Programming Instruction Set (Continued) a = address high bits, b = address low bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care Instruction TDI Sequence TDO Sequence Notes320 2552K–AVR–04/11 ATmega329/3290/649/6490 Notes: 1. This command sequence is not required if the seven MSB are correctly set by the previous command sequence (which is normally the case). 2. Repeat until o = “1”. 3. Set bits to “0” to program the corresponding Fuse, “1” to unprogram the Fuse. 4. Set bits to “0” to program the corresponding Lock bit, “1” to leave the Lock bit unchanged. 5. “0” = programmed, “1” = unprogrammed. 6. The bit mapping for Fuses Extended byte is listed in Table 27-3 on page 294 7. The bit mapping for Fuses High byte is listed in Table 27-4 on page 295 8. The bit mapping for Fuses Low byte is listed in Table 27-5 on page 295 9. The bit mapping for Lock bits byte is listed in Table 27-1 on page 293 10. Address bits exceeding PCMSB and EEAMSB (Table 27-10 and Table 27-11) are don’t care 11. All TDI and TDO sequences are represented by binary digits (0b...). 8f. Read Fuses and Lock Bits 0111010_00000000 0111110_00000000 0110010_00000000 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo xxxxxxx_oooooooo xxxxxxx_oooooooo xxxxxxx_oooooooo (5) Fuse Ext. byte Fuse High byte Fuse Low byte Lock bits 9a. Enter Signature Byte Read 0100011_00001000 xxxxxxx_xxxxxxxx 9b. Load Address Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 9c. Read Signature Byte 0110010_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 10a. Enter Calibration Byte Read 0100011_00001000 xxxxxxx_xxxxxxxx 10b. Load Address Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 10c. Read Calibration Byte 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 11a. Load No Operation Command 0100011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx Table 27-16. JTAG Programming Instruction Set (Continued) a = address high bits, b = address low bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care Instruction TDI Sequence TDO Sequence Notes321 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 27-16. State Machine Sequence for Changing/Reading the Data Word 27.8.11 Flash Data Byte Register The Flash Data Byte Register provides an efficient way to load the entire Flash page buffer before executing Page Write, or to read out/verify the content of the Flash. A state machine sets up the control signals to the Flash and senses the strobe signals from the Flash, thus only the data words need to be shifted in/out. The Flash Data Byte Register actually consists of the 8-bit scan chain and a 8-bit temporary register. During page load, the Update-DR state copies the content of the scan chain over to the temporary register and initiates a write sequence that within 11 TCK cycles loads the content of the temporary register into the Flash page buffer. The AVR automatically alternates between writing the low and the high byte for each new Update-DR state, starting with the low byte for the first Update-DR encountered after entering the PROG_PAGELOAD command. The Program Counter is pre-incremented before writing the low byte, except for the first written byte. This ensures that the first data is written to the address set up by PROG_COMMANDS, and loading the last location in the page buffer does not make the Program Counter increment into the next page. During Page Read, the content of the selected Flash byte is captured into the Flash Data Byte Register during the Capture-DR state. The AVR automatically alternates between reading the low and the high byte for each new Capture-DR state, starting with the low byte for the first CapTest-Logic-Reset Run-Test/Idle Shift-DR Exit1-DR Pause-DR Exit2-DR Update-DR Select-IR Scan Capture-IR Shift-IR Exit1-IR Pause-IR Exit2-IR Update-IR Select-DR Scan Capture-DR 0 1 0 11 1 0 0 0 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 0 0 1 1322 2552K–AVR–04/11 ATmega329/3290/649/6490 ture-DR encountered after entering the PROG_PAGEREAD command. The Program Counter is post-incremented after reading each high byte, including the first read byte. This ensures that the first data is captured from the first address set up by PROG_COMMANDS, and reading the last location in the page makes the program counter increment into the next page. Figure 27-17. Flash Data Byte Register The state machine controlling the Flash Data Byte Register is clocked by TCK. During normal operation in which eight bits are shifted for each Flash byte, the clock cycles needed to navigate through the TAP controller automatically feeds the state machine for the Flash Data Byte Register with sufficient number of clock pulses to complete its operation transparently for the user. However, if too few bits are shifted between each Update-DR state during page load, the TAP controller should stay in the Run-Test/Idle state for some TCK cycles to ensure that there are at least 11 TCK cycles between each Update-DR state. 27.8.12 Programming Algorithm All references below of type “1a”, “1b”, and so on, refer to Table 27-16. 27.8.13 Entering Programming Mode 1. Enter JTAG instruction AVR_RESET and shift 1 in the Reset Register. 2. Enter instruction PROG_ENABLE and shift 0b1010_0011_0111_0000 in the Programming Enable Register. 27.8.14 Leaving Programming Mode 1. Enter JTAG instruction PROG_COMMANDS. 2. Disable all programming instructions by using no operation instruction 11a. 3. Enter instruction PROG_ENABLE and shift 0b0000_0000_0000_0000 in the programming Enable Register. 4. Enter JTAG instruction AVR_RESET and shift 0 in the Reset Register. TDI TDO D A T A Flash EEPROM Fuses Lock Bits STROBES ADDRESS State Machine323 2552K–AVR–04/11 ATmega329/3290/649/6490 27.8.15 Performing Chip Erase 1. Enter JTAG instruction PROG_COMMANDS. 2. Start Chip Erase using programming instruction 1a. 3. Poll for Chip Erase complete using programming instruction 1b, or wait for tWLRH_CE (refer to Table 27-12 on page 307). 27.8.16 Programming the Flash Before programming the Flash a Chip Erase must be performed, see “Performing Chip Erase” on page 323. 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash write using programming instruction 2a. 3. Load address High byte using programming instruction 2b. 4. Load address Low byte using programming instruction 2c. 5. Load data using programming instructions 2d, 2e and 2f. 6. Repeat steps 4 and 5 for all instruction words in the page. 7. Write the page using programming instruction 2g. 8. Poll for Flash write complete using programming instruction 2h, or wait for tWLRH (refer to Table 27-12 on page 307). 9. Repeat steps 3 to 7 until all data have been programmed. A more efficient data transfer can be achieved using the PROG_PAGELOAD instruction: 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash write using programming instruction 2a. 3. Load the page address using programming instructions 2b and 2c. PCWORD (refer to Table 27-10 on page 298) is used to address within one page and must be written as 0. 4. Enter JTAG instruction PROG_PAGELOAD. 5. Load the entire page by shifting in all instruction words in the page byte-by-byte, starting with the LSB of the first instruction in the page and ending with the MSB of the last instruction in the page. Use Update-DR to copy the contents of the Flash Data Byte Register into the Flash page location and to auto-increment the Program Counter before each new word. 6. Enter JTAG instruction PROG_COMMANDS. 7. Write the page using programming instruction 2g. 8. Poll for Flash write complete using programming instruction 2h, or wait for tWLRH (refer to Table 27-12 on page 307). 9. Repeat steps 3 to 8 until all data have been programmed. 27.8.17 Reading the Flash 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash read using programming instruction 3a. 3. Load address using programming instructions 3b and 3c. 4. Read data using programming instruction 3d. 5. Repeat steps 3 and 4 until all data have been read. A more efficient data transfer can be achieved using the PROG_PAGEREAD instruction: 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash read using programming instruction 3a.324 2552K–AVR–04/11 ATmega329/3290/649/6490 3. Load the page address using programming instructions 3b and 3c. PCWORD (refer to Table 27-10 on page 298) is used to address within one page and must be written as 0. 4. Enter JTAG instruction PROG_PAGEREAD. 5. Read the entire page (or Flash) by shifting out all instruction words in the page (or Flash), starting with the LSB of the first instruction in the page (Flash) and ending with the MSB of the last instruction in the page (Flash). The Capture-DR state both captures the data from the Flash, and also auto-increments the program counter after each word is read. Note that Capture-DR comes before the shift-DR state. Hence, the first byte which is shifted out contains valid data. 6. Enter JTAG instruction PROG_COMMANDS. 7. Repeat steps 3 to 6 until all data have been read. 27.8.18 Programming the EEPROM Before programming the EEPROM a Chip Erase must be performed, see “Performing Chip Erase” on page 323. 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable EEPROM write using programming instruction 4a. 3. Load address High byte using programming instruction 4b. 4. Load address Low byte using programming instruction 4c. 5. Load data using programming instructions 4d and 4e. 6. Repeat steps 4 and 5 for all data bytes in the page. 7. Write the data using programming instruction 4f. 8. Poll for EEPROM write complete using programming instruction 4g, or wait for tWLRH (refer to Table 27-12 on page 307). 9. Repeat steps 3 to 8 until all data have been programmed. Note that the PROG_PAGELOAD instruction can not be used when programming the EEPROM. 27.8.19 Reading the EEPROM 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable EEPROM read using programming instruction 5a. 3. Load address using programming instructions 5b and 5c. 4. Read data using programming instruction 5d. 5. Repeat steps 3 and 4 until all data have been read. Note that the PROG_PAGEREAD instruction can not be used when reading the EEPROM. 27.8.20 Programming the Fuses 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Fuse write using programming instruction 6a. 3. Load data high byte using programming instructions 6b. A bit value of “0” will program the corresponding fuse, a “1” will unprogram the fuse. 4. Write Fuse High byte using programming instruction 6c. 5. Poll for Fuse write complete using programming instruction 6d, or wait for tWLRH (refer to Table 27-12 on page 307). 6. Load data low byte using programming instructions 6e. A “0” will program the fuse, a “1” will unprogram the fuse. 7. Write Fuse low byte using programming instruction 6f.325 2552K–AVR–04/11 ATmega329/3290/649/6490 8. Poll for Fuse write complete using programming instruction 6g, or wait for tWLRH (refer to Table 27-12 on page 307). 27.8.21 Programming the Lock Bits 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Lock bit write using programming instruction 7a. 3. Load data using programming instructions 7b. A bit value of “0” will program the corresponding lock bit, a “1” will leave the lock bit unchanged. 4. Write Lock bits using programming instruction 7c. 5. Poll for Lock bit write complete using programming instruction 7d, or wait for tWLRH (refer to Table 27-12 on page 307). Reading the Fuses and Lock Bits 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Fuse/Lock bit read using programming instruction 8a. 3. To read all Fuses and Lock bits, use programming instruction 8e. To only read Fuse High byte, use programming instruction 8b. To only read Fuse Low byte, use programming instruction 8c. To only read Lock bits, use programming instruction 8d. Reading the Signature Bytes 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Signature byte read using programming instruction 9a. 3. Load address 0x00 using programming instruction 9b. 4. Read first signature byte using programming instruction 9c. 5. Repeat steps 3 and 4 with address 0x01 and address 0x02 to read the second and third signature bytes, respectively. Reading the Calibration Byte 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Calibration byte read using programming instruction 10a. 3. Load address 0x00 using programming instruction 10b. Read the calibration byte using programming instruction 10c.326 2552K–AVR–04/11 ATmega329/3290/649/6490 28. Electrical Characteristics 28.1 Absolute Maximum Ratings* 28.2 DC Characteristics Operating Temperature.................................. -55°C to +125°C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ................................................ 40.0mA DC Current VCC and GND Pins................................. 200.0mA Table 28-1. TA = -40°C to 85°C, VCC = 1.8V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min. Typ. Max. Units VIL Input Low Voltage, Except XTAL1 pin VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V -0.5 -0.5 0.2VCC(1) 0.3VCC(1) V VIL1 Input Low Voltage, XTAL1 pin VCC = 1.8V - 5.5V -0.5 0.1VCC(1) V VIH Input High Voltage, Except XTAL1 and RESET pins VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.7VCC(2) 0.6VCC(2) VCC + 0.5 VCC + 0.5 V VIH1 Input High Voltage, XTAL1 pin VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.8VCC(2) 0.7VCC(2) VCC + 0.5 VCC + 0.5 V VIH2 Input High Voltage, RESET pin VCC = 1.8V - 5.5V 0.85VCC(2) VCC + 0.5 V VOL Output Low Voltage(3), Port A, C, D, E, F, G, H, J IOL = 10mA, VCC = 5V IOL = 5mA, VCC = 3V 0.7 0.5 V VOL1 Output Low Voltage(3), Port B I OL = 20mA, VCC = 5V IOL = 10mA, VCC = 3V 0.7 0.5 V VOH Output High Voltage(4), Port A, C, D, E, F, G, H, J IOH = -10mA, VCC = 5V IOH = -5mA, VCC = 3V 4.2 2.3 V VOH1 Output High Voltage(4), Port B IOH = -20mA, VCC = 5V IOH = -10mA, VCC = 3V 4.2 2.3 V IIL Input Leakage Current I/O Pin VCC = 5.5V, pin low (absolute value) 1 µA IIH Input Leakage Current I/O Pin VCC = 5.5V, pin high (absolute value) 1 µA RRST Reset Pull-up Resistor 20 100 kΩ RPU I/O Pin Pull-up Resistor 20 100 kΩ327 2552K–AVR–04/11 ATmega329/3290/649/6490 Notes: 1. “Max” means the highest value where the pin is guaranteed to be read as low 2. “Min” means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V for Port B and 10mA at VCC = 5V, 5mA at VCC = 3V for all other ports) under steady state conditions (non-transient), the following must be observed: TQFP and QFN/MLF Package: 1] The sum of all IOL, for all ports, should not exceed 400 mA. 2] The sum of all IOL, for ports A0 - A7, C4 - C7, G2 should not exceed 100mA. 3] The sum of all IOL, for ports B0 - B7, E0 - E7, G3 - G5 should not exceed 100mA. 4] The sum of all IOL, for ports D0 - D7, C0 - C3, G0 - G1 should not exceed 100mA. 5] The sum of all IOL, for ports F0 - F7, should not exceed 100mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20 mA at VCC = 5V, 10 mA at VCC = 3V for Port B and 10mA at VCC = 5V, 5mA at VCC = 3V for all other ports) under steady state conditions (non-transient), the following must be observed: TQFP and QFN/MLF Package: 1] The sum of all IOL, for all ports, should not exceed 400mA. 2] The sum of all IOL, for ports A0 - A7, C4 - C7, G2 should not exceed 100mA. 3] The sum of all IOL, for ports B0 - B7, E0 - E7, G3 - G5 should not exceed 100mA. 4] The sum of all IOL, for ports D0 - D7, C0 - C3, G0 - G1 should not exceed 100mA. 5] The sum of all IOL, for ports F0 - F7, should not exceed 100 mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 5. Typical values at 25°C. ICC Power Supply Current Active 1MHz, VCC = 2V 1.5 mA Active 4MHz, VCC = 3V 3.5 mA Active 8MHz, VCC = 5V 12 mA Idle 1MHz, VCC = 2V 0.45 mA Idle 4MHz, VCC = 3V 1.5 mA Idle 8MHz, VCC = 5V 5.5 mA Power-down mode(5) WDT enabled, VCC = 3V 7 15 µA WDT disabled, VCC = 3V 0.25 2 µA VACIO Analog Comparator Input Offset Voltage VCC = 5V Vin = VCC/2 <10 40 mV IACLK Analog Comparator Input Leakage Current VCC = 5V Vin = VCC/2 -50 50 nA tACID Analog Comparator Propagation Delay VCC = 2.7V VCC = 4.0V 750 500 ns Table 28-1. TA = -40°C to 85°C, VCC = 1.8V to 5.5V (unless otherwise noted) (Continued) Symbol Parameter Condition Min. Typ. Max. Units328 2552K–AVR–04/11 ATmega329/3290/649/6490 28.3 Speed Grades Figure 28-1. Maximum Frequency vs. VCC (4 - 8MHz). Figure 28-2. Maximum Frequency vs. VCC (8 - 16MHz). 8 MHz 4 MHz 1.8V 2.7V 5.5V Safe Operating Area 16 MHz 8 MHz 2.7V 4.5V 5.5V Safe Operating Area329 2552K–AVR–04/11 ATmega329/3290/649/6490 28.4 Clock Characteristics 28.4.1 Calibrated Internal RC Oscillator Accuracy Notes: 1. Voltage range for ATmega329V/3290V/649V/6490V. 2. Voltage range for ATmega329/3290/649/6490. 28.4.2 External Clock Drive Waveforms Figure 28-3. External Clock Drive Waveforms 28.4.3 External Clock Drive Table 28-2. Calibration Accuracy of Internal RC Oscillator Frequency VCC Temperature Calibration Accuracy Factory Calibration 8.0MHz 3V 25°C ±10% User Calibration 7.3 - 8.1MHz 1.8V - 5.5V(1) 2.7V - 5.5V(2) -40°C - 85°C ±1% VIL1 VIH1 Table 28-3. External Clock Drive Symbol Parameter VCC=1.8-5.5V VCC=2.7-5.5V VCC=4.5-5.5V Min. Max. Min. Max. Min. Max. Units 1/tCLCL Oscillator Frequency 040 8 0 16 MHz tCLCL Clock Period 1000 125 62.5 ns tCHCX High Time 400 50 25 ns tCLCX Low Time 400 50 25 ns tCLCH Rise Time 2.0 1.6 0.5 μs tCHCL Fall Time 2.0 1.6 0.5 μs ΔtCLCL Change in period from one clock cycle to the next 2 2 2%330 2552K–AVR–04/11 ATmega329/3290/649/6490 28.5 System and Reset Characteristics Notes: 1. The Power-on Reset will not work unless the supply voltage has been below VPOT (falling) Notes: 1. VBOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is tested down to VCC = VBOT during the production test. This guarantees that a Brown-Out Reset will occur before VCC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. The test is performed using BODLEVEL = 10 for ATmega329/3290/649/6490V and BODLEVEL = 01 for ATmega329/3290/649/6490L. Table 28-4. Reset, Brown-out, and Internal Voltage Reference Characteristics Symbol Parameter Condition Min Typ Max Units VPOT Power-on Reset Threshold Voltage (rising) TA = -40°C to 85°C 0.7 1.0 1.4 V Power-on Reset Threshold Voltage (falling)(1) TA = -40°C to 85°C 0.05 0.9 1.3 V VPSR Power-on Slope Rate 0.01 4.5 V/ms VRST RESET Pin Threshold Voltage VCC = 3V 0.2 VCC 0.85 VCC V t RST Minimum pulse width on RESET Pin VCC = 3V 800 ns VHYST Brown-out Detector Hysteresis 50 mV tBOD Min Pulse Width on Brown-out Reset 2 µs VBG Bandgap reference voltage VCC = 2.7V, TA = 25°C 1.0 1.1 1.2 V t BG Bandgap reference start-up time VCC = 2.7V, TA = 25°C 40 70 µs I BG Bandgap reference current consumption VCC = 2.7V, TA = 25°C 15 µA Table 28-5. BODLEVEL Fuse Coding(1) BODLEVEL 1:0 Fuses Min VBOT Typ VBOT Max VBOT Units 11 BOD Disabled 10 1.7 1.8 2.0 01 2.5 2.7 2.9 V 00 4.1 4.3 4.5331 2552K–AVR–04/11 ATmega329/3290/649/6490 28.6 SPI Timing Characteristics See Figure 28-4 and Figure 28-5 for details. Note: 1. In SPI Programming mode the minimum SCK high/low period is: - 2 tCLCL for fCK < 12MHz - 3 tCLCL for fCK > 12MHz Figure 28-4. SPI Interface Timing Requirements (Master Mode) Table 28-6. SPI Timing Parameters Description Mode Min Typ Max 1 SCK period Master See Table 18-5 ns 2 SCK high/low Master 50% duty cycle 3 Rise/Fall time Master 3.6 4 Setup Master 10 5 Hold Master 10 6 Out to SCK Master 0.5 • tsck 7 SCK to out Master 10 8 SCK to out high Master 10 9 SS low to out Slave 15 10 SCK period Slave 4 • tck 11 SCK high/low(1) Slave 2 • tck 12 Rise/Fall time Slave 1.6 µs 13 Setup Slave 10 ns 14 Hold Slave tck 15 SCK to out Slave 15 16 SCK to SS high Slave 20 17 SS high to tri-state Slave 10 18 SS low to SCK Slave 20 • tck MOSI (Data Output) SCK (CPOL = 1) MISO (Data Input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 6 1 2 2 4 5 3 7 8332 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 28-5. SPI Interface Timing Requirements (Slave Mode) MISO (Data Output) SCK (CPOL = 1) MOSI (Data Input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 10 11 11 13 14 12 15 17 9 X 16333 2552K–AVR–04/11 ATmega329/3290/649/6490 28.7 ADC Characteristics Table 28-7. ADC Characteristics Symbol Parameter Condition Min Typ Max Units Resolution Single Ended Conversion 10 Bits Differential Conversion 8 Bits Absolute accuracy (Including INL, DNL, quantization error, gain and offset error) Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 2 2.5 LSB Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 1MHz 4.5 LSB Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz Noise Reduction Mode 2 LSB Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 1MHz Noise Reduction Mode 4.5 LSB Integral Non-Linearity (INL) Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.5 LSB Differential Non-Linearity (DNL) Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.25 LSB Gain Error Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 2 LSB Offset Error Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 2 LSB Conversion Time Free Running Conversion 13 260 µs Clock Frequency Single Ended Conversion 50 1000 kHz AVCC Analog Supply Voltage VCC - 0.3 VCC + 0.3 V VREF Reference Voltage Single Ended Conversion 1.0 AVCC V Differential Conversion 1.0 AVCC - 0.5 V VIN Pin Input Voltage Single Ended Channels GND VREF V Differential Channels GND AVCC V Input Range Single Ended Channels GND VREF V Differential Channels(1) -0.85VREF VREF V Input Bandwidth Single Ended Channels 38.5 kHz Differential Channels 4 kHz334 2552K–AVR–04/11 ATmega329/3290/649/6490 Note: 1. Voltage difference between channels. 28.8 LCD Controller Characteristics VINT Internal Voltage Reference 1.0 1.1 1.2 V RREF Reference Input Resistance 32 kΩ RAIN Analog Input Resistance 100 MΩ Table 28-8. LCD Controller Characteristics Symbol Parameter Condition Min. Typ Max Units ILCD LCD Driver Current Total for All COM and SEG pins 6 µA RSEG Segment Driver Output Impedance 10 kΩ RCOM Blackplane Driver Output Impedance 2 kΩ Table 28-7. ADC Characteristics (Continued) Symbol Parameter Condition Min Typ Max Units335 2552K–AVR–04/11 ATmega329/3290/649/6490 29. Typical Characteristics The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A sine wave generator with rail-to-rail output is used as clock source. All Active- and Idle current consumption measurements are done with all bits in the PRR register set and thus, the corresponding I/O modules are turned off. Also the Analog Comparator is disabled during these measurements. See “Power Reduction Register” on page 37 for details. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as CL*VCC*f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. 29.0.1 Active Supply Current Figure 29-1. Active Supply Current vs. Frequency (0.1 - 1.0MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (m A)336 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-2. Active Supply Current vs. Frequency (1 - 16MHz)) Figure 29-3. Active Supply Current vs. VCC (Internal RC Oscillator, 8MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 Frequency (MHz) ICC (mA) 0 2 4 6 8 10 12 14 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C337 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-4. Active Supply Current vs. VCC (Internal RC Oscillator, CKDIV8 Programmed, 1MHz) Figure 29-5. Active Supply Current vs. VCC (32kHz External Oscillator) 0 0.5 1 1.5 2 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 70 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)338 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.2 Idle Supply Current Figure 29-6. Idle Supply Current vs. Frequency (0.1 - 1.0MHz) Figure 29-7. Idle Supply Current vs. Frequency (1 - 16MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 0 1 2 3 4 5 6 0 2 4 6 8 10 12 14 16 Frequency (MHz) ICC (mA) 1.8 V339 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-8. Idle Supply Current vs. VCC (Internal RC Oscillator, 8MHz) Figure 29-9. Idle Supply Current vs. VCC (Internal RC Oscillator, CKDIV8 Programmed, 1 MHz) 0 1 2 3 4 5 6 7 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85 C° 25 C° -40 C°340 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-10. Idle Supply Current vs. VCC (32kHz External Oscillator) 29.0.3 Supply Current of I/O modules The tables and formulas below can be used to calculate the additional current consumption for the different I/O modules in Active and Idle mode. The enabling or disabling of the I/O modules are controlled by the Power Reduction Register. See “Power Reduction Register” on page 37 for details. It is possible to calculate the typical current consumption based on the numbers from Table 29-2 for other VCC and frequency settings than listed in Table 29-1. 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) Table 29-1. Additional Current Consumption for the different I/O modules (absolute values) PRR bit Typical numbers VCC = 2V, F = 1MHz VCC = 3V, F = 4MHz VCC = 5V, F = 8MHz PRADC 17µA 116µA 562µA PRUSART0 9µA 59µA 248µA PRSPI 10µA 62µA 257µA PRTIM1 5µA 33µA 135µA PRLCD 6µA 36µA 146µA Table 29-2. Additional Current Consumption (percentage) in Active and Idle mode PRR bit Additional Current consumption compared to Active with external clock (see Figure 29-1 and Figure 29-2) Additional Current consumption compared to Idle with external clock (see Figure 29-6 and Figure 29-7) PRADC 5.4% 16.8% PRUSART0 2.7% 8.5% PRSPI 2.9% 9.0% PRTIM1 1.5% 4.8% PRLCD 1.7% 5.2%341 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.3.1 Example Calculate the expected current consumption in idle mode with USART0, TIMER1, and SPI enabled at VCC = 3.0V and F = 1MHz. Table 29-2 shows that we need to add 8.5% for the USART0, 9% for the SPI, and 4.8% for the TIMER1 module. From Figure 29-6, we find that the idle current consumption is ~0.16mA at VCC = 3.0V and F = 1MHz. The total current consumption in idle mode with USART0, TIMER1, and SPI enabled, gives: 29.0.4 Power-down Supply Current Figure 29-11. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) Figure 29-12. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) ICCtotal ≈ ≈ 0.16mA • ( ) 1 0.0 + ++ 85 0.09 0.048 0.20mA 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 3.5 4 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 2 4 6 8 10 12 14 16 18 20 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)342 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.5 Power-save Supply Current Figure 29-13. Power-save Supply Current vs. VCC (Watchdog Timer Disabled) 29.0.6 Standby Supply Current Figure 29-14. Standby Supply Current vs. VCC (Low Power Crystal Oscillator) 0 5 10 15 20 25 30 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C 6MHz Xtal 6MHz Res. 4MHz Xtal 4MHz Res. 455kHz Res. 32kHz Xtal 2MHz Xtal 2MHz Res. 1MHz Res. 0 20 40 60 80 100 120 140 160 180 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)343 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.7 Pin Pull-up Figure 29-15. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 5V) Figure 29-16. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 2.7V) 0 20 40 60 80 100 120 140 160 012345 VIO (V) IIO (uA) 85°C 25°C -40°C 0 10 20 30 40 50 60 70 80 90 0 0.5 1 1.5 2 2.5 3 VIO (V) IIO (uA) 85°C 25°C -40°C344 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-17. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 1.8V) Figure 29-18. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) 0 10 20 30 40 50 60 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOP (V) IOP (uA) 85°C 25°C -40°C 0 20 40 60 80 100 120 012345 VRESET (V) IRESET (uA) -40°C 25°C 85°C345 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-19. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) Figure 29-20. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 1.8V) 0 10 20 30 40 50 60 70 0 0.5 1 1.5 2 2.5 3 VRESET (V) IRESET (uA) -40°C 25°C 85°C 0 5 10 15 20 25 30 35 40 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VRESET (V) IRESET (uA) -40°C 25°C 85°C346 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.8 Pin Driver Strength Figure 29-21. I/O Pin Source Current vs. Output Voltage, Ports A, C, D, E, F, G, H, J (VCC = 5V) Figure 29-22. I/O Pin Source Current vs. Output Voltage, Ports A, C, D, E, F, G, H, J (VCC = 2.7V) 0 10 20 30 40 50 60 70 0123456 VOH (V) IOH (mA) 85°C 25°C -40°C 0 5 10 15 20 25 0 0.5 1 1.5 2 2.5 3 VOH (V) IOH (mA) 85°C 25°C -40°C347 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-23. I/O Pin Source Current vs. Output Voltage, Ports A, C, D, E, F, G, H, J (VCC = 1.8V) Figure 29-24. I/O Pin Source Current vs. Output Voltage, Port B (VCC= 5V) 0 1 2 3 4 5 6 7 8 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOH (V) IOH (mA) 85°C 25°C -40°C 0 10 20 30 40 50 60 70 80 01234 VOH (V) IOH (mA) 85°C 25°C -40°C348 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-25. I/O Pin Source Current vs. Output Voltage, Port B (VCC = 2.7V) Figure 29-26. I/O Pin Source Current vs. Output Voltage, Port B (VCC = 1.8V) 0 5 10 15 20 25 30 35 0 0.5 1 1.5 2 2.5 3 VOH (V) IOH (mA) 85°C 25°C -40°C 0 1 2 3 4 5 6 7 8 9 10 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOH (V) IOH (mA) 85°C 25°C -40°C349 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-27. I/O Pin Sink Current vs. Output Voltage, Ports A, C, D, E, F, G, H, J (VCC = 5V) Figure 29-28. I/O Pin Sink Current vs. Output Voltage, Ports A, C, D, E, F, G, H, J (VCC = 2.7V) 0 5 10 15 20 25 30 35 40 45 50 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C 0 2 4 6 8 10 12 14 16 18 20 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C350 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-29. I/O Pin Sink Current vs. Output Voltage, Ports A, C, D, E, F, G, H, J (VCC = 1.8V) Figure 29-30. I/O Pin Sink Current vs. Output Voltage, Port B (VCC = 5V) 0 1 2 3 4 5 6 7 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C 0 10 20 30 40 50 60 70 80 90 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C351 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-31. I/O Pin Sink Current vs. Output Voltage, Port B (VCC = 2.7V) Figure 29-32. I/O Pin Sink Current vs. Output Voltage, Port B (VCC = 1.8V) 0 5 10 15 20 25 30 35 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C 0 2 4 6 8 10 12 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C352 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.9 Pin Thresholds and hysteresis Figure 29-33. I/O Pin Input Threshold Voltage vs. VCC (VIH, I/O Pin Read as “1”) Figure 29-34. I/O Pin Input Threshold Voltage vs. VCC (VIL, I/O Pin Read as “0”) 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C353 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-35. I/O Pin Input Hysteresis vs. VCC Figure 29-36. Reset Input Threshold Voltage vs. VCC (VIH,Reset Pin Read as “1”) 0 0.1 0.2 0.3 0.4 0.5 0.6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) 85°C 25°C -40°C Input Hysteresis (V) 0 0.5 1 1.5 2 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C354 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-37. Reset Input Threshold Voltage vs. VCC (VIL,Reset Pin Read as “0”) Figure 29-38. Reset Input Pin Hysteresis vs. VCC 0 0.5 1 1.5 2 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (V) 85°C 25°C -40°C355 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.10 BOD Thresholds and Analog Comparator Offset Figure 29-39. BOD Thresholds vs. Temperature (BOD Level is 4.3V) Figure 29-40. BOD Thresholds vs. Temperature (BOD Level is 2.7V) Rising VCC Falling VCC 4 4.1 4.2 4.3 4.4 4.5 4.6 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) Threshold (V) Rising VCC Falling VCC 2.4 2.5 2.6 2.7 2.8 2.9 3 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) Threshol d ( V)356 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-41. BOD Thresholds vs. Temperature (BOD Level is 1.8V) Figure 29-42. Bandgap Voltage vs. VCC 1.7 1.75 1.8 1.85 1.9 1.95 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) Threshold (V) Rising VCC Falling VCC 85°C 25°C -40°C 1.068 1.069 1.07 1.071 1.072 1.073 1.074 1.075 1.076 1.5 2 2.5 3 3.5 4 4.5 5 VCC (V) Bandgap Voltage (V)357 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-43. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 5V) Figure 29-44. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 2.7V) 85°C 25°C -40°C 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Common Mode Voltage (V) Comparator Offset Voltage (V) 85°C 25°C 0 -40°C 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035 0 0.5 1 1.5 2 2.5 3 Common Mode Voltage (V) Comparator Offset Voltage (V)358 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.11 Internal Oscillator Speed Figure 29-45. Watchdog Oscillator Frequency vs. VCC Figure 29-46. Calibrated 8MHz RC Oscillator Frequency vs. Temperature 85 °C 25 °C -40 °C 1000 1050 1100 1150 1200 1250 1300 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (kHz) 5.5 V 4.5 V 3.3 V 2.7 V 1.8 V 7.2 7.4 7.6 7.8 8 8.2 8.4 8.6 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) FRC (M Hz)359 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-47. Calibrated 8MHz RC Oscillator Frequency vs. VCC Figure 29-48. Calibrated 8MHz RC Oscillator Frequency vs. Osccal Value 85 °C 25 °C -40 °C 7.2 7.4 7.6 7.8 8 8.2 8.4 8.6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85 °C 25 °C -40 °C 4 6 8 10 12 14 16 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL VALUE FRC (M Hz)360 2552K–AVR–04/11 ATmega329/3290/649/6490 29.0.12 Current Consumption of Peripheral Units Figure 29-49. Brownout Detector Current vs. VCC Figure 29-50. ADC Current vs. VCC (AREF = AVCC) 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 40 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 0 50 100 150 200 250 300 350 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C -40°C361 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-51. AREF External Reference Current vs. VCC Figure 29-52. 32kHz TOSC Current vs. VCC (Watchdog Timer Disabled) 0 20 40 60 80 100 120 140 160 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) IAREF (uA) 85°C 25°C -40°C 0 5 10 15 20 25 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C362 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-53. Watchdog Timer Current vs. VCC Figure 29-54. Analog Comparator Current vs. VCC 0 2 4 6 8 10 12 14 16 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C -40°C 0 20 40 60 80 100 120 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C -40°C363 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-55. Programming Current vs. VCC 29.0.13 Current Consumption in Reset and Reset Pulsewidth Figure 29-56. Reset Supply Current vs. VCC (0.1 - 1.0MHz, Excluding Current Through The Reset Pull-up) 85 °C 25 °C -40 °C 0 2 4 6 8 10 12 14 16 18 20 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)364 2552K–AVR–04/11 ATmega329/3290/649/6490 Figure 29-57. Reset Supply Current vs. VCC (1 - 16MHz, Excluding Current Through The Reset Pull-up) Figure 29-58. Reset Pulse Width vs. VCC 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.5 1 1.5 2 2.5 3 0 2 4 6 8 10 12 14 16 Frequency (MHz) ICC (mA) 0 500 1000 1500 2000 2500 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Pulsewidth (ns) 85°C 25°C -40°C365 2552K–AVR–04/11 ATmega329/3290/649/6490 30. Register Summary Note: Registers with bold type only available in ATmega3290/6490. Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page (0xFF) LCDDR19 SEG339 SEG338 SEG337 SEG336 SEG335 SEG334 SEG333 SEG332 244 (0xFE) LCDDR18 SEG331 SEG330 SEG329 SEG328 SEG327 SEG326 SEG325 SEG324 244 (0xFD) LCDDR17 SEG323 SEG322 SEG321 SEG320 SEG319 SEG318 SEG317 SEG316 244 (0xFC) LCDDR16 SEG315 SEG314 SEG313 SEG312 SEG311 SEG310 SEG309 SEG308 244 (0xFB) LCDDR15 SEG307 SEG306 SEG305 SEG304 SEG303 SEG302 SEG301 SEG300 244 (0xFA) LCDDR14 SEG239 SEG238 SEG237 SEG236 SEG235 SEG234 SEG233 SEG232 244 (0xF9) LCDDR13 SEG231 SEG230 SEG229 SEG228 SEG227 SEG226 SEG225 SEG224 244 (0xF8) LCDDR12 SEG223 SEG222 SEG221 SEG220 SEG219 SEG218 SEG217 SEG216 244 (0xF7) LCDDR11 SEG215 SEG214 SEG213 SEG212 SEG211 SEG210 SEG209 SEG208 244 (0xF6) LCDDR10 SEG207 SEG206 SEG205 SEG204 SEG203 SEG202 SEG201 SEG200 244 (0xF5) LCDDR09 SEG139 SEG138 SEG137 SEG136 SEG135 SEG134 SEG133 SEG132 244 (0xF4) LCDDR08 SEG131 SEG130 SEG129 SEG128 SEG127 SEG126 SEG125 SEG124 244 (0xF3) LCDDR07 SEG123 SEG122 SEG121 SEG120 SEG119 SEG118 SEG117 SEG116 244 (0xF2) LCDDR06 SEG115 SEG114 SEG113 SEG112 SEG111 SEG110 SEG109 SEG108 244 (0xF1) LCDDR05 SEG107 SEG106 SEG105 SEG104 SEG103 SEG102 SEG101 SEG100 244 (0xF0) LCDDR04 SEG039 SEG038 SEG037 SEG036 SEG035 SEG034 SEG033 SEG032 244 (0xEF) LCDDR03 SEG031 SEG030 SEG029 SEG028 SEG027 SEG026 SEG025 SEG024 244 (0xEE) LCDDR02 SEG023 SEG022 SEG021 SEG020 SEG019 SEG018 SEG017 SEG016 244 (0xED) LCDDR01 SEG015 SEG014 SEG013 SEG012 SEG011 SEG010 SEG009 SEG008 244 (0xEC) LCDDR00 SEG007 SEG006 SEG005 SEG004 SEG003 SEG002 SEG001 SEG000 244 (0xEB) Reserved - - - - - - - - (0xEA) Reserved - - - - - - - - (0xE9) Reserved - - - - - - - - (0xE8) Reserved - - - - - - - - (0xE7) LCDCCR LCDDC2 LCDDC1 LCDDC0 - LCDCC3 LCDCC2 LCDCC1 LCDCC0 243 (0xE6) LCDFRR - LCDPS2 LCDPS1 LCDPS0 - LCDCD2 LCDCD1 LCDCD0 241 (0xE5) LCDCRB LCDCS LCD2B LCDMUX1 LCDMUX0 LCDPM3 LCDPM2 LCDPM1 LCDPM0 239 (0xE4) LCDCRA LCDEN LCDAB - LCDIF LCDIE - - LCDBL 239 (0xE3) Reserved - - - - - - - - (0xE2) Reserved - - - - - - - - (0xE1) Reserved - - - - - - - - (0xE0) Reserved - - - - - - - - (0xDF) Reserved - - - - - - - - (0xDE) Reserved - - - - - - - - (0xDD) PORTJ - PORTJ6 PORTJ5 PORTJ4 PORTJ3 PORTJ2 PORTJ1 PORTJ0 90 (0xDC) DDRJ - DDJ6 DDJ5 DDJ4 DDJ3 DDJ2 DDJ1 DDJ0 90 (0xDB) PINJ - PINJ6 PINJ5 PINJ4 PINJ3 PINJ2 PINJ1 PINJ0 90 (0xDA) PORTH PORTH7 PORTH6 PORTH5 PORTH4 PORTH3 PORTH2 PORTH1 PORTH0 89 (0xD9) DDRH DDH7 DDH6 DDH5 DDH4 DDH3 DDH2 DDH1 DDH0 90 (0xD8) PINH PINH7 PINH6 PINH5 PINH4 PINH3 PINH2 PINH1 PINH0 90 (0xD7) Reserved - - - - - - - - (0xD6) Reserved - - - - - - - - (0xD5) Reserved - - - - - - - - (0xD4) Reserved - - - - - - - - (0xD3) Reserved - - - - - - - - (0xD2) Reserved - - - - - - - - (0xD1) Reserved - - - - - - - - (0xD0) Reserved - - - - - - - - (0xCF) Reserved - - - - - - - - (0xCE) Reserved - - - - - - - - (0xCD) Reserved - - - - - - - - (0xCC) Reserved - - - - - - - - (0xCB) Reserved - - - - - - - - (0xCA) Reserved - - - - - - - - (0xC9) Reserved - - - - - - - - (0xC8) Reserved - - - - - - - - (0xC7) Reserved - - - - - - - - (0xC6) UDR0 USART0 Data Register 190 (0xC5) UBRR0H USART0 Baud Rate Register High 194 (0xC4) UBRR0L USART0 Baud Rate Register Low 194366 2552K–AVR–04/11 ATmega329/3290/649/6490 (0xC3) Reserved - - - - - - - - (0xC2) UCSR0C - UMSEL0 UPM01 UPM00 USBS0 UCSZ01 UCSZ00 UCPOL0 192 (0xC1) UCSR0B RXCIE0 TXCIE0 UDRIE0 RXEN0 TXEN0 UCSZ02 RXB80 TXB80 191 (0xC0) UCSR0A RXC0 TXC0 UDRE0 FE0 DOR0 UPE0 U2X0 MPCM0 190 (0xBF) Reserved - - - - - - - - (0xBE) Reserved - - - - - - - - (0xBD) Reserved - - - - - - - - (0xBC) Reserved - - - - - - - - (0xBB) Reserved - - - - - - - - (0xBA) USIDR USI Data Register 203 (0xB9) USISR USISIF USIOIF USIPF USIDC USICNT3 USICNT2 USICNT1 USICNT0 203 (0xB8) USICR USISIE USIOIE USIWM1 USIWM0 USICS1 USICS0 USICLK USITC 204 (0xB7) Reserved - - - - - - - - (0xB6) ASSR - - - EXCLK AS2 TCN2UB OCR2UB TCR2UB 155 (0xB5) Reserved - - - - - - - - (0xB4) Reserved - - - - - - - - (0xB3) OCR2A Timer/Counter 2 Output Compare Register A 155 (0xB2) TCNT2 Timer/Counter2 155 (0xB1) Reserved - - - - - - - - (0xB0) TCCR2A FOC2A WGM20 COM2A1 COM2A0 WGM21 CS22 CS21 CS20 153 (0xAF) Reserved - - - - - - - - (0xAE) Reserved - - - - - - - - (0xAD) Reserved - - - - - - - - (0xAC) Reserved - - - - - - - - (0xAB) Reserved - - - - - - - - (0xAA) Reserved - - - - - - - - (0xA9) Reserved - - - - - - - - (0xA8) Reserved - - - - - - - - (0xA7) Reserved - - - - - - - - (0xA6) Reserved - - - - - - - - (0xA5) Reserved - - - - - - - - (0xA4) Reserved - - - - - - - - (0xA3) Reserved - - - - - - - - (0xA2) Reserved - - - - - - - - (0xA1) Reserved - - - - - - - - (0xA0) Reserved - - - - - - - - (0x9F) Reserved - - - - - - - - (0x9E) Reserved - - - - - - - - (0x9D) Reserved - - - - - - - - (0x9C) Reserved - - - - - - - - (0x9B) Reserved - - - - - - - - (0x9A) Reserved - - - - - - - - (0x99) Reserved - - - - - - - - (0x98) Reserved - - - - - - - - (0x97) Reserved - - - - - - - - (0x96) Reserved - - - - - - - - (0x95) Reserved - - - - - - - - (0x94) Reserved - - - - - - - - (0x93) Reserved - - - - - - - - (0x92) Reserved - - - - - - - - (0x91) Reserved - - - - - - - - (0x90) Reserved - - - - - - - - (0x8F) Reserved - - - - - - - - (0x8E) Reserved - - - - - - - - (0x8D) Reserved - - - - - - - - (0x8C) Reserved - - - - - - - - (0x8B) OCR1BH Timer/Counter1 Output Compare Register B High 136 (0x8A) OCR1BL Timer/Counter1 Output Compare Register B Low 136 (0x89) OCR1AH Timer/Counter1 Output Compare Register A High 136 (0x88) OCR1AL Timer/Counter1 Output Compare Register A Low 136 (0x87) ICR1H Timer/Counter1 Input Capture Register High 137 (0x86) ICR1L Timer/Counter1 Input Capture Register Low 137 (0x85) TCNT1H Timer/Counter1 High 136 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page367 2552K–AVR–04/11 ATmega329/3290/649/6490 (0x84) TCNT1L Timer/Counter1 Low 136 (0x83) Reserved - - - - - - - - (0x82) TCCR1C FOC1A FOC1B - - - - - - 135 (0x81) TCCR1B ICNC1 ICES1 - WGM13 WGM12 CS12 CS11 CS10 134 (0x80) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 - - WGM11 WGM10 132 (0x7F) DIDR1 - - - - - - AIN1D AIN0D 210 (0x7E) DIDR0 ADC7D ADC6D ADC5D ADC4D ADC3D ADC2D ADC1D ADC0D 227 (0x7D) Reserved - - - - - - - - (0x7C) ADMUX REFS1 REFS0 ADLAR MUX4 MUX3 MUX2 MUX1 MUX0 223 (0x7B) ADCSRB - ACME - - - ADTS2 ADTS1 ADTS0 209/227 (0x7A) ADCSRA ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 225 (0x79) ADCH ADC Data Register High 226 (0x78) ADCL ADC Data Register Low 226 (0x77) Reserved - - - - - - - - (0x76) Reserved - - - - - - - - (0x75) Reserved - - - - - - - - (0x74) Reserved - - - - - - - - (0x73) PCMSK3 - PCINT30 PCINT29 PCINT28 PCINT27 PCINT26 PCINT25 PCINT24 57 (0x72) Reserved - - - - - - - - (0x71) Reserved - - - - - - - - (0x70) TIMSK2 - - - - - - OCIE2A TOIE2 156 (0x6F) TIMSK1 - - ICIE1 - - OCIE1B OCIE1A TOIE1 137 (0x6E) TIMSK0 - - - - - - OCIE0A TOIE0 106 (0x6D) PCMSK2 PCINT23 PCINT22 PCINT21 PCINT20 PCINT19 PCINT18 PCINT17 PCINT16 57 (0x6C) PCMSK1 PCINT15 PCINT14 PCINT13 PCINT12 PCINT11 PCINT10 PCINT9 PCINT8 58 (0x6B) PCMSK0 PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 58 (0x6A) Reserved - - - - - - - - (0x69) EICRA - - - - - - ISC01 ISC00 55 (0x68) Reserved - - - - - - - - (0x67) Reserved - - - - - - - - (0x66) OSCCAL Oscillator Calibration Register [CAL7..0] 32 (0x65) Reserved - - - - - - - - (0x64) PRR - - - PRLCD PRTIM1 PRSPI PSUSART0 PRADC 40 (0x63) Reserved - - - - - - - - (0x62) Reserved - - - - - - - - (0x61) CLKPR CLKPCE - - - CLKPS3 CLKPS2 CLKPS1 CLKPS0 33 (0x60) WDTCR - - - WDCE WDE WDP2 WDP1 WDP0 48 0x3F (0x5F) SREG I T H S V N Z C 12 0x3E (0x5E) SPH Stack Pointer High 14 0x3D (0x5D) SPL Stack Pointer Low 14 0x3C (0x5C) Reserved - - - - - - - - 0x3B (0x5B) Reserved - - - - - - - - 0x3A (0x5A) Reserved - - - - - - - - 0x39 (0x59) Reserved - - - - - - - - 0x38 (0x58) Reserved - - - - - - - - 0x37 (0x57) SPMCSR SPMIE RWWSB - RWWSRE BLBSET PGWRT PGERS SPMEN 291 0x36 (0x56) Reserved 0x35 (0x55) MCUCR JTD - - PUD - - IVSEL IVCE 52/87/254 0x34 (0x54) MCUSR - - - JTRF WDRF BORF EXTRF PORF 47 0x33 (0x53) SMCR - - - - SM2 SM1 SM0 SE 39 0x32 (0x52) Reserved - - - - - - - - 0x31 (0x51) OCDR IDRD/OCDR7 OCDR6 OCDR5 OCDR4 OCDR3 OCDR2 OCDR1 OCDR0 250 0x30 (0x50) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 209 0x2F (0x4F) Reserved - - - - - - - - 0x2E (0x4E) SPDR SPI Data Register 167 0x2D (0x4D) SPSR SPIF WCOL - - - - - SPI2X 167 0x2C (0x4C) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 165 0x2B (0x4B) GPIOR2 General Purpose I/O Register 25 0x2A (0x4A) GPIOR1 General Purpose I/O Register 25 0x29 (0x49) Reserved - - - - - - - - 0x28 (0x48) Reserved - - - - - - - - 0x27 (0x47) OCR0A Timer/Counter0 Output Compare A 105 0x26 (0x46) TCNT0 Timer/Counter0 105 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page368 2552K–AVR–04/11 ATmega329/3290/649/6490 Note: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operate on the specified bit, and can therefore be used on registers containing such Status Flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only. 4. When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing I/O Registers as data space using LD and ST instructions, 0x20 must be added to these addresses. The ATmega329/3290/649/6490 is a complex microcontroller with more peripheral units than can be supported within the 64 location reserved in Opcode for the IN and OUT instructions. For the Extended I/O space from 0x60 - 0xFF in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used. 0x25 (0x45) Reserved - - - - - - - - 0x24 (0x44) TCCR0A FOC0A WGM00 COM0A1 COM0A0 WGM01 CS02 CS01 CS00 103 0x23 (0x43) GTCCR TSM - - - - - PSR2 PSR10 108/157 0x22 (0x42) EEARH - - - - - EEPROM Address Register High 22 0x21 (0x41) EEARL EEPROM Address Register Low 22 0x20 (0x40) EEDR EEPROM Data Register 22 0x1F (0x3F) EECR - - - - EERIE EEMWE EEWE EERE 22 0x1E (0x3E) GPIOR0 General Purpose I/O Register 25 0x1D (0x3D) EIMSK PCIE3 PCIE2 PCIE1 PCIE0 - - - INT0 55 0x1C (0x3C) EIFR PCIF3 PCIF2 PCIF1 PCIF0 - - - INTF0 56 0x1B (0x3B) Reserved - - - - - - - - 0x1A (0x3A) Reserved - - - - - - - - 0x19 (0x39) Reserved - - - - - - - - 0x18 (0x38) Reserved - - - - - - - - 0x17 (0x37) TIFR2 - - - - - - OCF2A TOV2 157 0x16 (0x36) TIFR1 - - ICF1 - - OCF1B OCF1A TOV1 138 0x15 (0x35) TIFR0 - - - - - - OCF0A TOV0 106 0x14 (0x34) PORTG - - - PORTG4 PORTG3 PORTG2 PORTG1 PORTG0 89 0x13 (0x33) DDRG - - - DDG4 DDG3 DDG2 DDG1 DDG0 89 0x12 (0x32) PING - - PING5 PING4 PING3 PING2 PING1 PING0 89 0x11 (0x31) PORTF PORTF7 PORTF6 PORTF5 PORTF4 PORTF3 PORTF2 PORTF1 PORTF0 89 0x10 (0x30) DDRF DDF7 DDF6 DDF5 DDF4 DDF3 DDF2 DDF1 DDF0 89 0x0F (0x2F) PINF PINF7 PINF6 PINF5 PINF4 PINF3 PINF2 PINF1 PINF0 89 0x0E (0x2E) PORTE PORTE7 PORTE6 PORTE5 PORTE4 PORTE3 PORTE2 PORTE1 PORTE0 88 0x0D (0x2D) DDRE DDE7 DDE6 DDE5 DDE4 DDE3 DDE2 DDE1 DDE0 88 0x0C (0x2C) PINE PINE7 PINE6 PINE5 PINE4 PINE3 PINE2 PINE1 PINE0 89 0x0B (0x2B) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 88 0x0A (0x2A) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 88 0x09 (0x29) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 88 0x08 (0x28) PORTC PORTC7 PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 88 0x07 (0x27) DDRC DDC7 DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 88 0x06 (0x26) PINC PINC7 PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 88 0x05 (0x25) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 87 0x04 (0x24) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 87 0x03 (0x23) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 87 0x02 (0x22) PORTA PORTA7 PORTA6 PORTA5 PORTA4 PORTA3 PORTA2 PORTA1 PORTA0 87 0x01 (0x21) DDRA DDA7 DDA6 DDA5 DDA4 DDA3 DDA2 DDA1 DDA0 87 0x00 (0x20) PINA PINA7 PINA6 PINA5 PINA4 PINA3 PINA2 PINA1 PINA0 87 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page369 2552K–AVR–04/11 ATmega329/3290/649/6490 31. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd ← Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd ← Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl ← Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd ← Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd ← Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd ← Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd ← Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl ← Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd ← Rd • Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd ← Rd • K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd ← Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd ← Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd ← Rd ⊕ Rr Z,N,V 1 COM Rd One’s Complement Rd ← 0xFF − Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd ← 0x00 − Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd ← Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd ← Rd • (0xFF - K) Z,N,V 1 INC Rd Increment Rd ← Rd + 1 Z,N,V 1 DEC Rd Decrement Rd ← Rd − 1 Z,N,V 1 TST Rd Test for Zero or Minus Rd ← Rd • Rd Z,N,V 1 CLR Rd Clear Register Rd ← Rd ⊕ Rd Z,N,V 1 SER Rd Set Register Rd ← 0xFF None 1 MUL Rd, Rr Multiply Unsigned R1:R0 ← Rd x Rr Z,C 2 MULS Rd, Rr Multiply Signed R1:R0 ← Rd x Rr Z,C 2 MULSU Rd, Rr Multiply Signed with Unsigned R1:R0 ← Rd x Rr Z,C 2 FMUL Rd, Rr Fractional Multiply Unsigned R1:R0 ← (Rd x Rr) << 1 Z,C 2 FMULS Rd, Rr Fractional Multiply Signed R1:R0 ← (Rd x Rr) << 1 Z,C 2 FMULSU Rd, Rr Fractional Multiply Signed with Unsigned R1:R0 ← (Rd x Rr) << 1 Z,C 2 BRANCH INSTRUCTIONS RJMP k Relative Jump PC ← PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC ← Z None 2 JMP k Direct Jump PC ← k None 3 RCALL k Relative Subroutine Call PC ← PC + k + 1 None 3 ICALL Indirect Call to (Z) PC ← Z None 3 CALL k Direct Subroutine Call PC ← k None 4 RET Subroutine Return PC ← STACK None 4 RETI Interrupt Return PC ← STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC ← PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd − Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd − Rr − C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd − K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC ← PC + 2 or 3 None 1/2/3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC ← PC + 2 or 3 None 1/2/3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PC←PC+k + 1 None 1/2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PC←PC+k + 1 None 1/2 BREQ k Branch if Equal if (Z = 1) then PC ← PC + k + 1 None 1/2 BRNE k Branch if Not Equal if (Z = 0) then PC ← PC + k + 1 None 1/2 BRCS k Branch if Carry Set if (C = 1) then PC ← PC + k + 1 None 1/2 BRCC k Branch if Carry Cleared if (C = 0) then PC ← PC + k + 1 None 1/2 BRSH k Branch if Same or Higher if (C = 0) then PC ← PC + k + 1 None 1/2 BRLO k Branch if Lower if (C = 1) then PC ← PC + k + 1 None 1/2 BRMI k Branch if Minus if (N = 1) then PC ← PC + k + 1 None 1/2 BRPL k Branch if Plus if (N = 0) then PC ← PC + k + 1 None 1/2 BRGE k Branch if Greater or Equal, Signed if (N ⊕ V= 0) then PC ← PC + k + 1 None 1/2 BRLT k Branch if Less Than Zero, Signed if (N ⊕ V= 1) then PC ← PC + k + 1 None 1/2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC ← PC + k + 1 None 1/2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC ← PC + k + 1 None 1/2 BRTS k Branch if T Flag Set if (T = 1) then PC ← PC + k + 1 None 1/2370 2552K–AVR–04/11 ATmega329/3290/649/6490 BRTC k Branch if T Flag Cleared if (T = 0) then PC ← PC + k + 1 None 1/2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC ← PC + k + 1 None 1/2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC ← PC + k + 1 None 1/2 BRIE k Branch if Interrupt Enabled if ( I = 1) then PC ← PC + k + 1 None 1/2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC ← PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b) ← 1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b) ← 0 None 2 LSL Rd Logical Shift Left Rd(n+1) ← Rd(n), Rd(0) ← 0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n) ← Rd(n+1), Rd(7) ← 0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)←C,Rd(n+1)← Rd(n),C←Rd(7) Z,C,N,V 1 ROR Rd Rotate Right Through Carry Rd(7)←C,Rd(n)← Rd(n+1),C←Rd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n) ← Rd(n+1), n=0..6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3..0)←Rd(7..4),Rd(7..4)←Rd(3..0) None 1 BSET s Flag Set SREG(s) ← 1 SREG(s) 1 BCLR s Flag Clear SREG(s) ← 0 SREG(s) 1 BST Rr, b Bit Store from Register to T T ← Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b) ← T None 1 SEC Set Carry C ← 1 C1 CLC Clear Carry C ← 0 C 1 SEN Set Negative Flag N ← 1 N 1 CLN Clear Negative Flag N ← 0 N 1 SEZ Set Zero Flag Z ← 1 Z1 CLZ Clear Zero Flag Z ← 0 Z 1 SEI Global Interrupt Enable I ← 1 I1 CLI Global Interrupt Disable I ← 0 I 1 SES Set Signed Test Flag S ← 1 S1 CLS Clear Signed Test Flag S ← 0 S 1 SEV Set Twos Complement Overflow. V ← 1 V1 CLV Clear Twos Complement Overflow V ← 0 V 1 SET Set T in SREG T ← 1 T1 CLT Clear T in SREG T ← 0 T 1 SEH Set Half Carry Flag in SREG H ← 1 H1 CLH Clear Half Carry Flag in SREG H ← 0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd ← Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd ← Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd ← K None 1 LD Rd, X Load Indirect Rd ← (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd ← (X), X ← X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X ← X - 1, Rd ← (X) None 2 LD Rd, Y Load Indirect Rd ← (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd ← (Y), Y ← Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y ← Y - 1, Rd ← (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd ← (Y + q) None 2 LD Rd, Z Load Indirect Rd ← (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd ← (Z), Z ← Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z ← Z - 1, Rd ← (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd ← (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd ← (k) None 2 ST X, Rr Store Indirect (X) ← Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) ← Rr, X ← X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X ← X - 1, (X) ← Rr None 2 ST Y, Rr Store Indirect (Y) ← Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y) ← Rr, Y ← Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y ← Y - 1, (Y) ← Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q) ← Rr None 2 ST Z, Rr Store Indirect (Z) ← Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z) ← Rr, Z ← Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z ← Z - 1, (Z) ← Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q) ← Rr None 2 STS k, Rr Store Direct to SRAM (k) ← Rr None 2 LPM Load Program Memory R0 ← (Z) None 3 LPM Rd, Z Load Program Memory Rd ← (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd ← (Z), Z ← Z+1 None 3 SPM Store Program Memory (Z) ← R1:R0 None - Mnemonics Operands Description Operation Flags #Clocks371 2552K–AVR–04/11 ATmega329/3290/649/6490 IN Rd, P In Port Rd ← P None 1 OUT P, Rr Out Port P ← Rr None 1 PUSH Rr Push Register on Stack STACK ← Rr None 2 POP Rd Pop Register from Stack Rd ← STACK None 2 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/timer) None 1 BREAK Break For On-chip Debug Only None N/A Mnemonics Operands Description Operation Flags #Clocks372 2552K–AVR–04/11 ATmega329/3290/649/6490 32. Ordering Information Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging alternative, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. For Speed vs. VCC see Figure 28-1 on page 328 and Figure 28-2 on page 328. 4. Tape & Reel 32.1 ATmega329 Speed (MHz)(3) Power Supply Ordering Code(2) Package Type(1) Operational Range 8 1.8 - 5.5V ATmega329V-8AU ATmega329V-8AUR(4) ATmega329V-8MU ATmega329V-8MUR(4) 64A 64A 64M1 64M1 Industrial (-40°C to 85°C) 16 2.7 - 5.5V ATmega329-16AU ATmega329-16AUR(4) ATmega329-16MU ATmega329-16MUR(4) 64A 64A 64M1 64M1 Industrial (-40°C to 85°C) Package Type 64A 64-lead, 14 x 14 x 1.0 mm, Thin Profile Plastic Quad Flat Package (TQFP) 64M1 64-pad, 9 x 9 x 1.0 mm, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF) 100A 100-lead, 14 x 14 x 1.0 mm, 0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP)373 2552K–AVR–04/11 ATmega329/3290/649/6490 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging alternative, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. For Speed vs. VCC see Figure 28-1 on page 328 and Figure 28-2 on page 328. 4. Tape & Reel 32.2 ATmega3290 Speed (MHz)(3) Power Supply Ordering Code(2) Package Type(1) Operational Range 8 1.8 - 5.5V ATmega3290V-8AU ATmega3290V-8AUR(4) 100A 100A Industrial (-40°C to 85°C) 16 2.7 - 5.5V ATmega3290-16AU ATmega3290-16AUR(4) 100A 100A Industrial (-40°C to 85°C) Package Type 64A 64-lead, 14 x 14 x 1.0 mm, Thin Profile Plastic Quad Flat Package (TQFP) 64M1 64-pad, 9 x 9 x 1.0 mm, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF) 100A 100-lead, 14 x 14 x 1.0 mm, 0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP)374 2552K–AVR–04/11 ATmega329/3290/649/6490 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging alternative, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. For Speed vs. VCC see Figure 28-1 on page 328 and Figure 28-2 on page 328. 4. Tape & Reel 32.3 ATmega649 Speed (MHz)(3) Power Supply Ordering Code(2) Package Type(1) Operational Range 8 1.8 - 5.5V ATmega649V-8AU ATmega649V-8AUR(4) ATmega649V-8MU ATmega649V-8MUR(4) 64A 64A 64M1 64M1 Industrial (-40°C to 85°C) 16 2.7 - 5.5V ATmega649-16AU ATmega649-16AUR(4) ATmega649-16MU ATmega649-16MUR(4) 64A 64A 64M1 64M1 Industrial (-40°C to 85°C) Package Type 64A 64-lead, 14 x 14 x 1.0 mm, Thin Profile Plastic Quad Flat Package (TQFP) 64M1 64-pad, 9 x 9 x 1.0 mm, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF) 100A 100-lead, 14 x 14 x 1.0 mm, 0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP)375 2552K–AVR–04/11 ATmega329/3290/649/6490 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging alternative, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. For Speed Grades see Figure 28-1 on page 328 and Figure 28-2 on page 328. 4. Tape & Reel 32.4 ATmega6490 Speed (MHz)(3) Power Supply Ordering Code(2) Package Type(1) Operational Range 8 1.8 - 5.5V ATmega6490V-8AU ATmega6490V-8AUR(4) 100A 100A Industrial (-40°C to 85°C) 16 2.7 - 5.5V ATmega6490-16AU ATmega6490-16AUR(4) 100A 100A Industrial (-40°C to 85°C) Package Type 64A 64-lead, 14 x 14 x 1.0 mm, Thin Profile Plastic Quad Flat Package (TQFP) 64M1 64-pad, 9 x 9 x 1.0 mm, Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF) 100A 100-lead, 14 x 14 x 1.0 mm, 0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP)376 2552K–AVR–04/11 ATmega329/3290/649/6490 33. Packaging Information 33.1 64A 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 64A, 64-lead, 14 x 14 mm Body Size, 1.0 mm Body Thickness, 0.8 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP) 64A C 2010-10-20 PIN 1 IDENTIFIER 0°~7° PIN 1 L C A1 A2 A D1 D e E1 E B COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE Notes: 1.This package conforms to JEDEC reference MS-026, Variation AEB. 2. Dimensions D1 and E1 do not include mold protrusion. Allowable protrusion is 0.25 mm per side. Dimensions D1 and E1 are maximum plastic body size dimensions including mold mismatch. 3. Lead coplanarity is 0.10 mm maximum. A – – 1.20 A1 0.05 – 0.15 A2 0.95 1.00 1.05 D 15.75 16.00 16.25 D1 13.90 14.00 14.10 Note 2 E 15.75 16.00 16.25 E1 13.90 14.00 14.10 Note 2 B 0.30 – 0.45 C 0.09 – 0.20 L 0.45 – 0.75 e 0.80 TYP377 2552K–AVR–04/11 ATmega329/3290/649/6490 33.2 64M1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 64M1, 64-pad, 9 x 9 x 1.0 mm Body, Lead Pitch 0.50 mm, 64M1 H 2010-10-19 COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A 0.80 0.90 1.00 A1 – 0.02 0.05 b 0.18 0.25 0.30 D D2 5.20 5.40 5.60 8.90 9.00 9.10 E 8.90 9.00 9.10 E2 5.20 5.40 5.60 e 0.50 BSC L 0.35 0.40 0.45 Notes: 1. JEDEC Standard MO-220, (SAW Singulation) Fig. 1, VMMD. 2. Dimension and tolerance conform to ASMEY14.5M-1994. TOP VIEW SIDE VIEW BOTTOM VIEW D E Marked Pin# 1 ID SEATING PLANE A1 C A 0.08 C 1 2 3 K 1.25 1.40 1.55 E2 D2 b e Pin #1 Corner L Pin #1 Triangle Pin #1 Chamfer (C 0.30) Option A Option B Pin #1 Notch (0.20 R) Option C K K 5.40 mm Exposed Pad, Micro Lead Frame Package (MLF) 378 2552K–AVR–04/11 ATmega329/3290/649/6490 33.3 100A 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 100A, 100-lead, 14 x 14 mm Body Size, 1.0 mm Body Thickness, 0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP) 100A D 2010-10-20 PIN 1 IDENTIFIER 0°~7° PIN 1 L C A1 A2 A D1 D e E1 E B A – – 1.20 A1 0.05 – 0.15 A2 0.95 1.00 1.05 D 15.75 16.00 16.25 D1 13.90 14.00 14.10 Note 2 E 15.75 16.00 16.25 E1 13.90 14.00 14.10 Note 2 B 0.17 – 0.27 C 0.09 – 0.20 L 0.45 – 0.75 e 0.50 TYP Notes: 1. This package conforms to JEDEC reference MS-026, Variation AED. 2. Dimensions D1 and E1 do not include mold protrusion. Allowable protrusion is 0.25 mm per side. Dimensions D1 and E1 are maximum plastic body size dimensions including mold mismatch. 3. Lead coplanarity is 0.08 mm maximum. COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE379 2552K–AVR–04/11 ATmega329/3290/649/6490 34. Errata 34.1 ATmega329 34.1.1 ATmega329 rev. C • Interrupts may be lost when writing the timer registers in the asynchronous timer 1. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix/Wortkaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx). 34.1.2 ATmega329 rev. B Not sampled. 34.1.3 ATmega329 rev. A • LCD contrast voltage too high • Interrupts may be lost when writing the timer registers in the asynchronous timer 1. LCD contrast voltage too high When the LCD is active and using low power waveform, the LCD contrast voltage can be too high. This occurs when VCC is higher than VLCD, and when using low LCD drivetime. Problem Fix/Workaround There are several possible workarounds: - Use normal waveform instead of low power waveform - Use drivetime of 375 µs or longer 2. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix/Wortkaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).380 2552K–AVR–04/11 ATmega329/3290/649/6490 34.2 ATmega3290 34.2.1 ATmega3290 rev. C • Interrupts may be lost when writing the timer registers in the asynchronous timer 1. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix/Wortkaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx). 34.2.2 ATmega3290 rev. B Not sampled. 34.2.3 ATmega3290 rev. A • LCD contrast voltage too high • Interrupts may be lost when writing the timer registers in the asynchronous timer 1. LCD contrast voltage too high When the LCD is active and using low power waveform, the LCD contrast voltage can be too high. This occurs when VCC is higher than VLCD, and when using low LCD drivetime. Problem Fix/Workaround There are several possible workarounds: - Use normal waveform instead of low power waveform - Use drivetime of 375 µs or longer 2. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix/Wortkaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).381 2552K–AVR–04/11 ATmega329/3290/649/6490 34.3 ATmega649 34.3.1 ATmega649 rev. A • Interrupts may be lost when writing the timer registers in the asynchronous timer 1. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix/Wortkaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx). 34.4 ATmega6490 34.4.1 ATmega6490 rev. A • Interrupts may be lost when writing the timer registers in the asynchronous timer 1. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix/Wortkaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).382 2552K–AVR–04/11 ATmega329/3290/649/6490 35. Datasheet Revision History Please note that the referring page numbers in this section are referring to this document.The referring revision in this section are referring to the document revision. 35.1 Rev. 2552K – 04/11 35.2 Rev. 2552J – 08/07 35.3 Rev. 2552I – 04/07 35.4 Rev. 2552H – 11/06 1. Removed “Preliminary” from the front page. 2. Removed “Disclaimer Section” from the datasheet. 3. Updated Table 28-5 on page 330 “BODLEVEL Fuse Coding(1)” . 4. Updated Table 28-8 on page 334 “LCD Controller Characteristics” . 5. Updated “Ordering Information” on page 372 to include “Tape & Reel” devices. The “AI” and “MI” devices removed. 6. Updated “Errata” on page 379. 7. Updated the datasheet according to the Atmel new brand style guide, including the last page. 1. Updated “Features” on page 1. 2. Added “Data Retention” on page 9. 3. Updated “Serial Programming Algorithm” on page 309. 4. Updated “Speed Grades” on page 328. 5. Updated “System and Reset Characteristics” on page 330. 6. Moved Register Descriptions to the end of each chapter. 1. Updated date in backpage 2. Updated column in Table 28-5 on page 330. 1. Updated Table 28-7 on page 333. 2. Updated note in Table 28-7 on page 333 and Table 28-2 on page 329.383 2552K–AVR–04/11 ATmega329/3290/649/6490 35.5 Rev. 2552G – 07/06 35.6 Rev. 2552F – 06/06 35.7 Rev. 2552E – 04/06 35.8 Rev. 2552D – 03/06 35.9 Rev. 2552C – 03/06 1. Updated Table 14-2 on page 104, Table 14-4 on page 104, Table 16-3 on page 133, Table 16-5 on page 134, Table 16-5 on page 134, Table 17-2 on page 153 and Table 17-4 on page 154. 2. Updated “Fast PWM Mode” on page 124. 3. Updated Features in “USI – Universal Serial Interface” on page 195. 4. Added “Clock speed considerations.” on page 202. 5. “Errata” on page 379. 1. Updated “Calibrated Internal RC Oscillator” on page 29. 2. Updated “OSCCAL – Oscillator Calibration Register” on page 32 3. Added Table 28-2 on page 329. 1. Updated “Calibrated Internal RC Oscillator” on page 29. 1. Updated “Errata” on page 379. 1. Added “Resources” on page 9. 2. Added Addresses in Registers. 3. Updated number of General Purpose I/O pins. 4. Updated code example in “Bit 0 – IVCE: Interrupt Vector Change Enable” on page 53. 5. Updated Introduction in “I/O-Ports” on page 59. 6. Updated “SPI – Serial Peripheral Interface” on page 158. 7. Updated “Bit 6 – ACBG: Analog Comparator Bandgap Select” on page 209. 8. Updated Features in “Analog to Digital Converter” on page 211. 9. Updated “Prescaling and Conversion Timing” on page 214. 10. Updated features in “LCD Controller” on page 228. 11. Updated “ATmega329/3290/649/6490 Boot Loader Parameters” on page 290. 12. Updated “DC Characteristics” on page 310. 13. Updated “” on page 334.384 2552K–AVR–04/11 ATmega329/3290/649/6490 35.10 Rev. 2552B – 05/05 35.11 Rev. 2552A –11/04 1. MLF-package alternative changed to “Quad Flat No-Lead/Micro Lead Frame Package QFN/MLF”. 2. Added “Pin Change Interrupt Timing” on page 54. 3. Updated Table 23-6 on page 242, Table 23-7 on page 243 and Table 27-15 on page 310. 4. Added Figure 27-12 on page 312. 5. Updated Figure 22-9 on page 219 and Figure 27-5 on page 304. 6. Updated algorithm “Enter Programming Mode” on page 299. 7. Added “Supply Current of I/O modules” on page 340. 8. Updated “Ordering Information” on page 372. 1. Initial version.i 2552K–AVR–04/11 ATmega329/3290/649/6490 Table of Contents Features ..................................................................................................... 1 1 Pin Configurations ................................................................................... 2 2 Overview ................................................................................................... 4 2.1 Block Diagram ...................................................................................................4 2.2 Comparison between ATmega329, ATmega3290, ATmega649 and ATmega6490 6 2.3 Pin Descriptions .................................................................................................6 3 Resources ................................................................................................. 9 4 Data Retention .......................................................................................... 9 5 About Code Examples ............................................................................. 9 6 AVR CPU Core ........................................................................................ 10 6.1 Overview ..........................................................................................................10 6.2 Architectural Overview .....................................................................................10 6.3 ALU – Arithmetic Logic Unit .............................................................................11 6.4 AVR Status Register ........................................................................................12 6.5 General Purpose Register File ........................................................................13 6.6 Stack Pointer ...................................................................................................14 6.7 Instruction Execution Timing ...........................................................................15 6.8 Reset and Interrupt Handling ...........................................................................15 7 AVR ATmega329/3290/649/6490 Memories ......................................... 18 7.1 In-System Reprogrammable Flash Program Memory .....................................18 7.2 SRAM Data Memory ........................................................................................19 7.3 EEPROM Data Memory ..................................................................................20 7.4 I/O Memory ......................................................................................................21 7.5 Register Description ........................................................................................22 8 System Clock and Clock Options ......................................................... 26 8.1 Clock Systems and their Distribution ...............................................................26 8.2 Clock Sources .................................................................................................27 8.3 Crystal Oscillator .............................................................................................28 8.4 Low-frequency Crystal Oscillator .....................................................................29 8.5 Calibrated Internal RC Oscillator .....................................................................29 8.6 External Clock .................................................................................................31ii 2552K–AVR–04/11 ATmega329/3290/649/6490 8.7 Clock Output Buffer .........................................................................................31 8.8 Timer/Counter Oscillator ..................................................................................32 8.9 System Clock Prescaler ..................................................................................32 8.10 Register Description ........................................................................................32 9 Power Management and Sleep Modes ................................................. 35 9.1 Idle Mode .........................................................................................................36 9.2 ADC Noise Reduction Mode ............................................................................36 9.3 Power-down Mode ...........................................................................................36 9.4 Power-save Mode ............................................................................................36 9.5 Standby Mode .................................................................................................37 9.6 Power Reduction Register ...............................................................................37 9.7 Minimizing Power Consumption ......................................................................37 9.8 Register Description ........................................................................................39 10 System Control and Reset .................................................................... 41 10.1 Resetting the AVR ...........................................................................................41 10.2 Reset Sources .................................................................................................41 10.3 Power-on Reset ...............................................................................................42 10.4 External Reset .................................................................................................43 10.5 Brown-out Detection ........................................................................................43 10.6 Watchdog Reset ..............................................................................................44 10.7 Internal Voltage Reference ..............................................................................44 10.8 Watchdog Timer ..............................................................................................45 10.9 Timed Sequences for Changing the Configuration of the Watchdog Timer ....47 10.10 Register Description ........................................................................................47 11 Interrupts ................................................................................................ 49 11.1 Interrupt Vectors in ATmega329/3290/649/6490 .............................................49 11.2 Register Description ........................................................................................52 12 External Interrupts ................................................................................. 54 12.1 Pin Change Interrupt Timing ............................................................................54 12.2 Register Description ........................................................................................55 13 I/O-Ports .................................................................................................. 59 13.1 Introduction ......................................................................................................59 13.2 Ports as General Digital I/O .............................................................................60 13.3 Alternate Port Functions ..................................................................................65iii 2552K–AVR–04/11 ATmega329/3290/649/6490 13.4 Register Description ........................................................................................87 14 8-bit Timer/Counter0 with PWM ............................................................ 91 14.1 Features ..........................................................................................................91 14.2 Overview ..........................................................................................................91 14.3 Timer/Counter Clock Sources .........................................................................92 14.4 Counter Unit ....................................................................................................93 14.5 Output Compare Unit .......................................................................................93 14.6 Compare Match Output Unit ............................................................................95 14.7 Modes of Operation .........................................................................................97 14.8 Timer/Counter Timing Diagrams ...................................................................101 14.9 Register Description ......................................................................................103 15 Timer/Counter0 and Timer/Counter1 Prescalers .............................. 107 15.1 Register Description ......................................................................................108 16 16-bit Timer/Counter1 .......................................................................... 110 16.1 Features ........................................................................................................110 16.2 Overview ........................................................................................................110 16.3 Accessing 16-bit Registers ............................................................................113 16.4 Timer/Counter Clock Sources .......................................................................116 16.5 Counter Unit ..................................................................................................116 16.6 Input Capture Unit .........................................................................................117 16.7 Output Compare Units ...................................................................................119 16.8 Compare Match Output Unit ..........................................................................122 16.9 Modes of Operation .......................................................................................123 16.10 Timer/Counter Timing Diagrams ...................................................................130 16.11 Register Description ......................................................................................132 17 8-bit Timer/Counter2 with PWM and Asynchronous Operation ...... 139 17.1 Features ........................................................................................................139 17.2 Overview ........................................................................................................139 17.3 Timer/Counter Clock Sources .......................................................................140 17.4 Counter Unit ..................................................................................................140 17.5 Output Compare Unit .....................................................................................141 17.6 Compare Match Output Unit ..........................................................................144 17.7 Modes of Operation .......................................................................................145 17.8 Timer/Counter Timing Diagrams ...................................................................149 17.9 Asynchronous Operation of Timer/Counter2 .................................................151iv 2552K–AVR–04/11 ATmega329/3290/649/6490 17.10 Timer/Counter Prescaler ...............................................................................152 17.11 Register Description ......................................................................................153 18 SPI – Serial Peripheral Interface ......................................................... 158 18.1 Features ........................................................................................................158 18.2 Overview ........................................................................................................158 18.3 SS Pin Functionality ......................................................................................163 18.4 Data Modes ...................................................................................................164 18.5 Register Description ......................................................................................165 19 USART0 ................................................................................................. 168 19.1 Features ........................................................................................................168 19.2 Overview ........................................................................................................168 19.3 Clock Generation ...........................................................................................169 19.4 Frame Formats ..............................................................................................172 19.5 USART Initialization .......................................................................................173 19.6 Data Transmission – The USART Transmitter ..............................................175 19.7 Data Reception – The USART Receiver .......................................................177 19.8 Asynchronous Data Reception ......................................................................181 19.9 Multi-processor Communication Mode ..........................................................185 19.10 Examples of Baud Rate Setting .....................................................................186 19.11 Register Description ......................................................................................190 20 USI – Universal Serial Interface .......................................................... 195 20.1 Features ........................................................................................................195 20.2 Overview ........................................................................................................195 20.3 Functional Descriptions .................................................................................196 20.4 Alternative USI Usage ...................................................................................202 20.5 Register Descriptions ....................................................................................203 21 Analog Comparator ............................................................................. 207 21.1 Overview ........................................................................................................207 21.2 Analog Comparator Multiplexed Input ...........................................................208 21.3 Register Description ......................................................................................209 22 Analog to Digital Converter ................................................................ 211 22.1 Features ........................................................................................................211 22.2 Operation .......................................................................................................212 22.3 Starting a Conversion ....................................................................................213v 2552K–AVR–04/11 ATmega329/3290/649/6490 22.4 Prescaling and Conversion Timing ................................................................214 22.5 Changing Channel or Reference Selection ...................................................216 22.6 ADC Conversion Result .................................................................................221 22.7 Register Description ......................................................................................223 23 LCD Controller ..................................................................................... 228 23.1 Features ........................................................................................................228 23.2 Mode of Operation .........................................................................................231 23.3 LCD Usage ....................................................................................................235 23.4 Register Description ......................................................................................239 24 JTAG Interface and On-chip Debug System ..................................... 245 24.1 Features ........................................................................................................245 24.2 Overview ........................................................................................................245 24.3 Test Access Port – TAP ................................................................................245 24.4 TAP Controller ...............................................................................................247 24.5 Using the Boundary-scan Chain ....................................................................248 24.6 Using the On-chip Debug System .................................................................248 24.7 On-chip Debug Specific JTAG Instructions ...................................................249 24.8 Using the JTAG Programming Capabilities ...................................................250 24.9 Bibliography ...................................................................................................250 24.10 Register Description ......................................................................................250 25 IEEE 1149.1 (JTAG) Boundary-scan ................................................... 251 25.1 Features ........................................................................................................251 25.2 System Overview ...........................................................................................251 25.3 Data Registers ...............................................................................................251 25.4 Boundary-scan Specific JTAG Instructions ...................................................253 25.5 Boundary-scan Related Register in I/O Memory ...........................................254 25.6 Boundary-scan Chain ....................................................................................255 25.7 ATmega329/3290/649/6490 Boundary-scan Order .......................................264 25.8 Boundary-scan Description Language Files ..................................................277 26 Boot Loader Support – Read-While-Write Self-Programming ......... 278 26.1 Features ........................................................................................................278 26.2 Application and Boot Loader Flash Sections .................................................278 26.3 Read-While-Write and No Read-While-Write Flash Sections ........................278 26.4 Boot Loader Lock Bits ...................................................................................281 26.5 Entering the Boot Loader Program ................................................................282vi 2552K–AVR–04/11 ATmega329/3290/649/6490 26.6 Addressing the Flash During Self-Programming ...........................................283 26.7 Self-Programming the Flash ..........................................................................283 26.8 Register Description ......................................................................................291 27 Memory Programming ......................................................................... 293 27.1 Program And Data Memory Lock Bits ...........................................................293 27.2 Fuse Bits ........................................................................................................294 27.3 Signature Bytes .............................................................................................296 27.4 Calibration Byte .............................................................................................296 27.5 Parallel Programming Parameters, Pin Mapping, and Commands ...............296 27.6 Parallel Programming ....................................................................................299 27.7 Serial Downloading ........................................................................................308 27.8 Programming via the JTAG Interface ............................................................313 28 Electrical Characteristics .................................................................... 326 28.1 Absolute Maximum Ratings* .........................................................................326 28.2 DC Characteristics .........................................................................................326 28.3 Speed Grades ...............................................................................................328 28.4 Clock Characteristics .....................................................................................329 28.5 System and Reset Characteristics ................................................................330 28.6 SPI Timing Characteristics ............................................................................331 28.7 ADC Characteristics ......................................................................................333 28.8 LCD Controller Characteristics ......................................................................334 29 Typical Characteristics ........................................................................ 335 30 Register Summary ............................................................................... 365 31 Instruction Set Summary .................................................................... 369 32 Ordering Information ........................................................................... 372 32.1 ATmega329 ...................................................................................................372 32.2 ATmega3290 .................................................................................................373 32.3 ATmega649 ...................................................................................................374 32.4 ATmega6490 .................................................................................................375 33 Packaging Information ........................................................................ 376 33.1 64A ................................................................................................................376 33.2 64M1 ..............................................................................................................377 33.3 100A ..............................................................................................................378vii 2552K–AVR–04/11 ATmega329/3290/649/6490 34 Errata ..................................................................................................... 379 34.1 ATmega329 ...................................................................................................379 34.2 ATmega3290 .................................................................................................380 34.3 ATmega649 ...................................................................................................381 34.4 ATmega6490 .................................................................................................381 35 Datasheet Revision History ................................................................ 382 35.1 Rev. 2552K – 04/11 .......................................................................................382 35.2 Rev. 2552J – 08/07 .......................................................................................382 35.3 Rev. 2552I – 04/07 ........................................................................................382 35.4 Rev. 2552H – 11/06 .......................................................................................382 35.5 Rev. 2552G – 07/06 ......................................................................................383 35.6 Rev. 2552F – 06/06 .......................................................................................383 35.7 Rev. 2552E – 04/06 .......................................................................................383 35.8 Rev. 2552D – 03/06 .......................................................................................383 35.9 Rev. 2552C – 03/06 .......................................................................................383 35.10 Rev. 2552B – 05/05 .......................................................................................384 35.11 Rev. 2552A –11/04 ........................................................................................384 Table of Contents....................................................................................... i2552K–AVR–04/11 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: (+1)(408) 441-0311 Fax: (+1)(408) 487-2600 www.atmel.com Atmel Asia Limited Unit 1-5 & 16, 19/F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 JAPAN Tel: (+81)(3) 3523-3551 Fax: (+81)(3) 3523-7581 © 2011 Atmel Corporation. All rights reserved. Atmel®, Atmel logo and combinations thereof, AVR® and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. 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Features • High Performance, Low Power AVR® 8-Bit Microcontroller • Advanced RISC Architecture – 120 Powerful Instructions – Most Single Clock Cycle Execution – 32 x 8 General Purpose Working Registers – Fully Static Operation – Up to 20 MIPS Throughput at 20 MHz • Data and Non-volatile Program and Data Memories – 2/4K Bytes of In-System Self Programmable Flash • Endurance 10,000 Write/Erase Cycles – 128/256 Bytes In-System Programmable EEPROM • Endurance: 100,000 Write/Erase Cycles – 128/256 Bytes Internal SRAM – Programming Lock for Flash Program and EEPROM Data Security • Peripheral Features – One 8-bit Timer/Counter with Separate Prescaler and Compare Mode – One 16-bit Timer/Counter with Separate Prescaler, Compare and Capture Modes – Four PWM Channels – On-chip Analog Comparator – Programmable Watchdog Timer with On-chip Oscillator – USI – Universal Serial Interface – Full Duplex USART • Special Microcontroller Features – debugWIRE On-chip Debugging – In-System Programmable via SPI Port – External and Internal Interrupt Sources – Low-power Idle, Power-down, and Standby Modes – Enhanced Power-on Reset Circuit – Programmable Brown-out Detection Circuit – Internal Calibrated Oscillator • I/O and Packages – 18 Programmable I/O Lines – 20-pin PDIP, 20-pin SOIC, 20-pad MLF/VQFN • Operating Voltage – 1.8 – 5.5V • Speed Grades – 0 – 4 MHz @ 1.8 – 5.5V – 0 – 10 MHz @ 2.7 – 5.5V – 0 – 20 MHz @ 4.5 – 5.5V • Industrial Temperature Range: -40°C to +85°C • Low Power Consumption – Active Mode • 190 µA at 1.8V and 1MHz – Idle Mode • 24 µA at 1.8V and 1MHz – Power-down Mode • 0.1 µA at 1.8V and +25°C 8-bit Microcontroller with 2/4K Bytes In-System Programmable Flash ATtiny2313A ATtiny4313 Rev. 8246B–AVR–09/112 8246B–AVR–09/11 ATtiny2313A/4313 1. Pin Configurations Figure 1-1. Pinout ATtiny2313A/4313 (PCINT10/RESET/dW) PA2 (PCINT11/RXD) PD0 (PCINT12/TXD) PD1 (PCINT9/XTAL2) PA1 (PCINT8/CLKI/XTAL1) PA0 (PCINT13/CKOUT/XCK/INT0) PD2 (PCINT14/INT1) PD3 (PCINT15/T0) PD4 (PCINT16/OC0B/T1) PD5 GND 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 VCC PB7 (USCK/SCL/SCK/PCINT7) PB6 (MISO/DO/PCINT6) PB5 (MOSI/DI/SDA/PCINT5) PB4 (OC1B/PCINT4) PB3 (OC1A/PCINT3) PB2 (OC0A/PCINT2) PB1 (AIN1/PCINT1) PB0 (AIN0/PCINT0) PD6 (ICPI/PCINT17) PDIP/SOIC 1 2 3 4 5 MLF/VQFN 15 14 13 12 11 20 19 18 17 16 6 7 8 9 10 (PCINT12/TXD) PD1 (PCINT9/XTAL2) PA1 (PCINT8/CLKI/XTAL1) PA0 (PCINT13/CKOUT/XCK/INT0) PD2 (PCINT14/INT1) PD3 (PCINT15/T0) PD4 (PCINT16/OC0B/T1) PD5 GND (PCINT17/ICPI) PD6 (AIN0/PCINT0) PB0 PB5 (MOSI/DI/SDA/PCINT5) PB4 (OC1B/PCINT4) PB3 (OC1A/PCINT3) PB2 (OC0A/PCINT2) PB1 (AIN1/PCINT1) PD0 (RXD/PCINT11) PA2 (RESET/dW/PCINT10) VCC PB7 (USCK/SCL/SCK/PCINT7) PB6 (MISO/DO/PCINT6) NOTE: Bottom pad should be soldered to ground.3 8246B–AVR–09/11 ATtiny2313A/4313 1.1 Pin Descriptions 1.1.1 VCC Digital supply voltage. 1.1.2 GND Ground. 1.1.3 Port A (PA2..PA0) Port A is a 3-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port A output buffers have symmetrical drive characteristics with both high sink and source capability, except PA2 which has the RESET capability. To use pin PA2 as I/O pin, instead of RESET pin, program (“0”) RSTDISBL fuse. As inputs, Port A pins that are externally pulled low will source current if the pull-up resistors are activated. The Port A pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port A also serves the functions of various special features of the ATtiny2313A/4313 as listed on page 62. 1.1.4 Port B (PB7..PB0) Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port B also serves the functions of various special features of the ATtiny2313A/4313 as listed on page 63. 1.1.5 Port D (PD6..PD0) Port D is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port D also serves the functions of various special features of the ATtiny2313A/4313 as listed on page 67. 1.1.6 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running and provided that the reset pin has not been disabled. The minimum pulse length is given in Table 22-3 on page 201. Shorter pulses are not guaranteed to generate a reset. The Reset Input is an alternate function for PA2 and dW. The reset pin can also be used as a (weak) I/O pin. 1.1.7 XTAL1 Input to the inverting Oscillator amplifier and input to the internal clock operating circuit. XTAL1 is an alternate function for PA0.4 8246B–AVR–09/11 ATtiny2313A/4313 1.1.8 XTAL2 Output from the inverting Oscillator amplifier. XTAL2 is an alternate function for PA1.5 8246B–AVR–09/11 ATtiny2313A/4313 2. Overview The ATtiny2313A/4313 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny2313A/4313 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. 2.1 Block Diagram Figure 2-1. Block Diagram PROGRAM COUNTER PROGRAM FLASH INSTRUCTION REGISTER GND VCC INSTRUCTION DECODER CONTROL LINES STACK POINTER SRAM GENERAL PURPOSE REGISTER ALU STATUS REGISTER PROGRAMMING LOGIC SPI 8-BIT DATA BUS XTAL1 XTAL2 RESET INTERNAL OSCILLATOR OSCILLATOR WATCHDOG TIMER TIMING AND CONTROL MCU CONTROL REGISTER MCU STATUS REGISTER TIMER/ COUNTERS INTERRUPT UNIT EEPROM USI USART ANALOG COMPARATOR DATA REGISTER PORTB DATA DIR. REG. PORTB DATA REGISTER PORTA DATA DIR. REG. PORTA PORTB DRIVERS PB0 - PB7 PORTA DRIVERS PA0 - PA2 DATA REGISTER PORTD DATA DIR. REG. PORTD PORTD DRIVERS PD0 - PD6 ON-CHIP DEBUGGER INTERNAL CALIBRATED OSCILLATOR6 8246B–AVR–09/11 ATtiny2313A/4313 The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The ATtiny2313A/4313 provides the following features: 2/4K bytes of In-System Programmable Flash, 128/256 bytes EEPROM, 128/256 bytes SRAM, 18 general purpose I/O lines, 32 general purpose working registers, a single-wire Interface for On-chip Debugging, two flexible Timer/Counters with compare modes, internal and external interrupts, a serial programmable USART, Universal Serial Interface with Start Condition Detector, a programmable Watchdog Timer with internal Oscillator, and three software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, and interrupt system to continue functioning. The Power-down mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next interrupt or hardware reset. In Standby mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low-power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The On-chip ISP Flash allows the program memory to be reprogrammed In-System through an SPI serial interface, or by a conventional non-volatile memory programmer. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the Atmel ATtiny2313A/4313 is a powerful microcontroller that provides a highly flexible and cost effective solution to many embedded control applications. The ATtiny2313A/4313 AVR is supported with a full suite of program and system development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit Emulators, and Evaluation kits. 2.2 Comparison Between ATtiny2313A and ATtiny4313 The ATtiny2313A and ATtiny4313 differ only in memory sizes. Table 2-1 summarizes the different memory sizes for the two devices. Table 2-1. Memory Size Summary Device Flash EEPROM RAM ATtiny2313A 2K Bytes 128 Bytes 128 Bytes ATtiny4313 4K Bytes 256 Bytes 256 Bytes7 8246B–AVR–09/11 ATtiny2313A/4313 3. About 3.1 Resources A comprehensive set of drivers, application notes, data sheets and descriptions on development tools are available for download at http://www.atmel.com/avr. 3.2 Code Examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. For I/O Registers located in the extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with instructions that allow access to extended I/O. Typically, this means “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”. Note that not all AVR devices include an extended I/O map. 3.3 Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C.8 8246B–AVR–09/11 ATtiny2313A/4313 4. CPU Core This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. 4.1 Architectural Overview Figure 4-1. Block Diagram of the AVR Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is In-System Reprogrammable Flash memory. The fast-access Register File contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Flash Program Memory Instruction Register Instruction Decoder Program Counter Control Lines 32 x 8 General Purpose Registrers ALU Status and Control I/O Lines EEPROM Data Bus 8-bit Data SRAM Direct Addressing Indirect Addressing Interrupt Unit SPI Unit Watchdog Timer Analog Comparator I/O Module 2 I/O Module1 I/O Module n9 8246B–AVR–09/11 ATtiny2313A/4313 Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every program memory address contains a 16- or 32-bit instruction. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, and other I/O functions. The I/O Memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. 4.2 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See the “Instruction Set” section for a detailed description. 4.3 Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software.10 8246B–AVR–09/11 ATtiny2313A/4313 The AVR Status Register – SREG – is defined as: • Bit 7 – I: Global Interrupt Enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the instruction set reference. • Bit 6 – T: Bit Copy Storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half Carry Flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry Is useful in BCD arithmetic. See the “Instruction Set Description” for detailed information. • Bit 4 – S: Sign Bit, S = N ⊕ V The S-bit is always an exclusive or between the negative flag N and the Two’s Complement Overflow Flag V. See the “Instruction Set Description” for detailed information. • Bit 3 – V: Two’s Complement Overflow Flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See the “Instruction Set Description” for detailed information. • Bit 2 – N: Negative Flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 1 – Z: Zero Flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 0 – C: Carry Flag The Carry Flag C indicates a carry in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. Bit 7 6 5 4 3 2 1 0 0x3F (0x5F) I T H S V N Z C SREG Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 011 8246B–AVR–09/11 ATtiny2313A/4313 4.4 General Purpose Register File The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 4-2 shows the structure of the 32 general purpose working registers in the CPU. Figure 4-2. AVR CPU General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 4-2, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y- and Z-pointer registers can be set to index any register in the file. 4.4.1 The X-register, Y-register, and Z-register The registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 4-3. 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E Purpose R15 0x0F Working R16 0x10 Registers R17 0x11 … R26 0x1A X-register Low Byte R27 0x1B X-register High Byte R28 0x1C Y-register Low Byte R29 0x1D Y-register High Byte R30 0x1E Z-register Low Byte R31 0x1F Z-register High Byte12 8246B–AVR–09/11 ATtiny2313A/4313 Figure 4-3. The X-, Y-, and Z-registers In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the instruction set reference for details). 4.5 Stack Pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x60. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when data is popped from the Stack with return from subroutine RET or return from interrupt RETI. The Stack Pointer is implemented as one 8-bit register in the I/O space. 4.6 Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 4-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. 15 XH XL 0 X-register 7 07 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 07 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 70 7 0 R31 (0x1F) R30 (0x1E) Bit 7 6 5 4 3 2 1 0 0x3D (0x5D) SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND13 8246B–AVR–09/11 ATtiny2313A/4313 Figure 4-4. The Parallel Instruction Fetches and Instruction Executions Figure 4-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 4-5. Single Cycle ALU Operation 4.7 Reset and Interrupt Handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate program vector in the program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. The lowest addresses in the program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 48. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. Refer to “Interrupts” on page 48 for more information. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the interrupt flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding interrupt flag. Interrupt flags can also be cleared by writing a logic one to the flag bit position(s) to be clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPU Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPU14 8246B–AVR–09/11 ATtiny2313A/4313 cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the interrupt flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding interrupt flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have interrupt flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence.. When using the SEI instruction to enable interrupts, the instruction following SEI will be executed before any pending interrupts, as shown in this example. Assembly Code Example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMPE ; start EEPROM write sbi EECR, EEPE out SREG, r16 ; restore SREG value (I-bit) C Code Example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ __disable_interrupt(); EECR |= (1< xxx ... ... ... ... 9.2 External Interrupts External Interrupts are triggered by the INT0 or INT1 pin or any of the PCINT17..0 pins. Observe that, if enabled, the interrupts will trigger even if the INT0, INT1 or PCINT17..0 pins are configured as outputs. This feature provides a way of generating a software interrupt. Pin change 0 interrupts PCI0 will trigger if any enabled PCINT7..0 pin toggles. Pin change 1 interrupts PCI1 will trigger if any enabled PCINT10..8 pin toggles. Pin change 2 interrupts PCI2 will trigger, if any enabled PCINT17..11 pin toggles. The PCMSK0, PCMSK1, and PCMSK2 Registers control which pins contribute to the pin change interrupts. Pin change interrupts on PCINT17..0 are detected asynchronously, which means that these interrupts can be used for waking the part also from sleep modes other than Idle mode. The INT0 and INT1 interrupts can be triggered by a falling or rising edge or a low level. This is set up as shown in “MCUCR – MCU Control Register” on page 51. When the INT0 or INT1 interrupt is enabled and configured as level triggered, the interrupt will trigger as long as the pin is held low. Note that recognition of falling or rising edge interrupts on INT0 or INT1 requires the presence of an I/O clock, as described in “Clock Sources” on page 27.50 8246B–AVR–09/11 ATtiny2313A/4313 9.2.1 Low Level Interrupt A low level interrupt on INT0 or INT1 is detected asynchronously. This means that the interrupt source can be used for waking the part also from sleep modes other than Idle (the I/O clock is halted in all sleep modes except Idle). Note that if a level triggered interrupt is used for wake-up from Power-down, the required level must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If the level disappears before the end of the Start-up Time, the MCU will still wake up, but no interrupt will be generated. The start-up time is defined by the SUT and CKSEL fuses, as described in “Clock System” on page 26. If the low level on the interrupt pin is removed before the device has woken up then program execution will not be diverted to the interrupt service routine but continue from the instruction following the SLEEP command. 9.2.2 Pin Change Interrupt Timing A timing example of a pin change interrupt is shown in Figure 9-1. Figure 9-1. Timing of pin change interrupts clk PCINT(0) pin_lat pin_sync pcint_in_(0) pcint_syn pcint_setflag PCIF PCINT(0) pin_sync pcint_syn pin_lat D Q LE pcint_setflag PCIF clk clk PCINT(0) in PCMSK(x) pcint_in_(0) 0 x51 8246B–AVR–09/11 ATtiny2313A/4313 9.3 Register Description 9.3.1 MCUCR – MCU Control Register The External Interrupt Control Register contains control bits for interrupt sense control. • Bit 3, 2 – ISC11, ISC10: Interrupt Sense Control 1 Bit 1 and Bit 0 The External Interrupt 1 is activated by the external pin INT1 if the SREG I-flag and the corresponding interrupt mask are set. The level and edges on the external INT1 pin that activate the interrupt are defined in Table 9-2. The value on the INT1 pin is sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. If low level interrupt is selected, the low level must be held until the completion of the currently executing instruction to generate an interrupt • Bits 1, 0 – ISC01, ISC00: Interrupt Sense Control 0 Bit 1 and Bit 0 The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set. The level and edges on the external INT0 pin that activate the interrupt are defined in Table 9-3. The value on the INT0 pin is sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. If low level interrupt is selected, the low level must be held until the completion of the currently executing instruction to generate an interrupt. Bit 7 6 5 4 3 2 1 0 0x35 (0x55) PUD SM1 SE SM0 ISC11 ISC10 ISC01 ISC00 MCUCR Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 9-2. Interrupt 1 Sense Control ISC11 ISC10 Description 0 0 The low level of INT1 generates an interrupt request. 0 1 Any logical change on INT1 generates an interrupt request. 1 0 The falling edge of INT1 generates an interrupt request. 1 1 The rising edge of INT1 generates an interrupt request. Table 9-3. Interrupt 0 Sense Control ISC01 ISC00 Description 0 0 The low level of INT0 generates an interrupt request. 0 1 Any logical change on INT0 generates an interrupt request. 1 0 The falling edge of INT0 generates an interrupt request. 1 1 The rising edge of INT0 generates an interrupt request.52 8246B–AVR–09/11 ATtiny2313A/4313 9.3.2 GIMSK – General Interrupt Mask Register • Bits 2..0 – Res: Reserved Bits These bits are reserved and will always read as zero. • Bit 7 – INT1: External Interrupt Request 1 Enable When the INT1 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is enabled. The Interrupt Sense Control bits (ISC11 and ISC10) in the External Interrupt Control Register A (EICRA) define whether the external interrupt is activated on rising and/or falling edge of the INT1 pin or level sensed. Activity on the pin will cause an interrupt request even if INT1 is configured as an output. The corresponding interrupt of External Interrupt Request 1 is executed from the INT1 Interrupt Vector. • Bit 6 – INT0: External Interrupt Request 0 Enable When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is enabled. The Interrupt Sense Control bits (ISC01 and ISC00) in the External Interrupt Control Register A (EICRA) define whether the external interrupt is activated on rising and/or falling edge of the INT0 pin or level sensed. Activity on the pin will cause an interrupt request even if INT0 is configured as an output. The corresponding interrupt of External Interrupt Request 0 is executed from the INT0 Interrupt Vector. • Bit 5 – PCIE0: Pin Change Interrupt Enable 0 When the PCIE0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin change interrupt 0 is enabled. Any change on any enabled PCINT7..0 pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI0 Interrupt Vector. PCINT7..0 pins are enabled individually by the PCMSK0 Register. • Bit 4 – PCIE2: Pin Change Interrupt Enable 2 When the PCIE2 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin change interrupt 2 is enabled. Any change on any enabled PCINT17..11 pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI2 Interrupt Vector. PCINT17..11 pins are enabled individually by the PCMSK2 Register. • Bit 3 – PCIE1: Pin Change Interrupt Enable 1 When the PCIE1 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin change interrupt 1 is enabled. Any change on any enabled PCINT10..8 pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI1 Interrupt Vector. PCINT10..8 pins are enabled individually by the PCMSK1 Register. Bit 7 6 5 4 3 2 1 0 0x3B (0x5B) INT1 INT0 PCIE0 PCIE2 PCIE1 – – – GIMSK Read/Write R/W R/W R/W R/W R/W R R R Initial Value 0 0 0 0 0 0 0 053 8246B–AVR–09/11 ATtiny2313A/4313 9.3.3 GIFR – General Interrupt Flag Register • Bits 2..0 – Res: Reserved Bits These bits are reserved and will always read as zero. • Bit 7 – INTF1: External Interrupt Flag 1 When an edge or logic change on the INT1 pin triggers an interrupt request, INTF1 becomes set (one). If the I-bit in SREG and the INT1 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. This flag is always cleared when INT1 is configured as a level interrupt. • Bit 6 – INTF0: External Interrupt Flag 0 When an edge or logic change on the INT0 pin triggers an interrupt request, INTF0 becomes set (one). If the I-bit in SREG and the INT0 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. This flag is always cleared when INT0 is configured as a level interrupt. • Bit 5 – PCIF0: Pin Change Interrupt Flag 0 When a logic change on any PCINT7..0 pin triggers an interrupt request, PCIF becomes set (one). If the I-bit in SREG and the PCIE0 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. • Bit 4 – PCIF2: Pin Change Interrupt Flag 2 When a logic change on any PCINT17..11 pin triggers an interrupt request, PCIF2 becomes set (one). If the I-bit in SREG and the PCIE2 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. • Bit 3 – PCIF1: Pin Change Interrupt Flag 1 When a logic change on any PCINT10..8 pin triggers an interrupt request, PCIF1 becomes set (one). If the I-bit in SREG and the PCIE1 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. 9.3.4 PCMSK2 – Pin Change Mask Register 2 • Bit 7 – Res: Reserved Bit These bits are reserved and will always read as zero. Bit 7 6 5 4 3 2 1 0 0x3A (0x5A) INTF1 INTF0 PCIF0 PCIF2 PCIF1 – – – GIFR Read/Write R/W R/W R/W R/W R/W R R R Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x05 (0x25) – PCINT17 PCINT16 PCINT15 PCINT14 PCINT13 PCINT12 PCINT11 PCMSK2 Read/Write R R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 054 8246B–AVR–09/11 ATtiny2313A/4313 • Bits 6..0 – PCINT17..11: Pin Change Enable Mask 17..11 Each PCINT17..11 bit selects whether pin change interrupt is enabled on the corresponding I/O pin. If PCINT17..11 is set and the PCIE1 bit in GIMSK is set, pin change interrupt is enabled on the corresponding I/O pin. If PCINT17..11 is cleared, pin change interrupt on the corresponding I/O pin is disabled. 9.3.5 PCMSK1 – Pin Change Mask Register 1 • Bits 7:3 – Res: Reserved Bits These bits are reserved and will always read as zero. • Bits 2..0 – PCINT10..8: Pin Change Enable Mask 10..8 Each PCINT10..8 bit selects whether pin change interrupt is enabled on the corresponding I/O pin. If PCINT10..8 is set and the PCIE1 bit in GIMSK is set, pin change interrupt is enabled on the corresponding I/O pin. If PCINT10..8 is cleared, pin change interrupt on the corresponding I/O pin is disabled. 9.3.6 PCMSK0 – Pin Change Mask Register 0 • Bits 7..0 – PCINT7..0: Pin Change Enable Mask 7..0 Each PCINT7..0 bit selects whether pin change interrupt is enabled on the corresponding I/O pin. If PCINT7..0 is set and the PCIE0 bit in GIMSK is set, pin change interrupt is enabled on the corresponding I/O pin. If PCINT7..0 is cleared, pin change interrupt on the corresponding I/O pin is disabled. Bit 7 6 5 4 3 2 1 0 0x04 (0x24) – – – – – PCINT10 PCINT9 PCINT8 PCMSK1 Read/Write R R R R R R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x20 (0x40) PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 PCMSK0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 055 8246B–AVR–09/11 ATtiny2313A/4313 10. I/O-Ports All AVR ports have true Read-Modify-Write functionality when used as general digital I/O ports. This means that the direction of one port pin can be changed without unintentionally changing the direction of any other pin with the SBI and CBI instructions. The same applies when changing drive value (if configured as output) or enabling/disabling of pull-up resistors (if configured as input). Each output buffer has symmetrical drive characteristics with both high sink and source capability. The pin driver is strong enough to drive LED displays directly. All port pins have individually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O pins have protection diodes to both VCC and Ground as indicated in Figure 10-1 on page 55. See “Electrical Characteristics” on page 198 for a complete list of parameters. Figure 10-1. I/O Pin Equivalent Schematic All registers and bit references in this section are written in general form. A lower case “x” represents the numbering letter for the port, and a lower case “n” represents the bit number. However, when using the register or bit defines in a program, the precise form must be used. For example, PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O Registers and bit locations are listed in “Register Description” on page 69. Three I/O memory address locations are allocated for each port, one each for the Data Register – PORTx, Data Direction Register – DDRx, and the Port Input Pins – PINx. The Port Input Pins I/O location is read only, while the Data Register and the Data Direction Register are read/write. However, writing a logic one to a bit in the PINx Register, will result in a toggle in the corresponding bit in the Data Register. In addition, the Pull-up Disable – PUD bit in MCUCR disables the pull-up function for all pins in all ports when set. Using the I/O port as General Digital I/O is described in “Ports as General Digital I/O” on page 56. Most port pins are multiplexed with alternate functions for the peripheral features on the device. How each alternate function interferes with the port pin is described in “Alternate Port Functions” on page 60. Refer to the individual module sections for a full description of the alternate functions. Note that enabling the alternate function of some of the port pins does not affect the use of the other pins in the port as general digital I/O. Cpin Logic Rpu See Figure "General Digital I/O" for Details Pxn56 8246B–AVR–09/11 ATtiny2313A/4313 10.1 Ports as General Digital I/O The ports are bi-directional I/O ports with optional internal pull-ups. Figure 10-2 shows a functional description of one I/O-port pin, here generically called Pxn. Figure 10-2. General Digital I/O(1) Note: 1. WRx, WPx, WDx, RRx, RPx, and RDx are common to all pins within the same port. clkI/O, SLEEP, and PUD are common to all ports. 10.1.1 Configuring the Pin Each port pin consists of three register bits: DDxn, PORTxn, and PINxn. As shown in “Register Description” on page 69, the DDxn bits are accessed at the DDRx I/O address, the PORTxn bits at the PORTx I/O address, and the PINxn bits at the PINx I/O address. The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written logic one, Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is configured as an input pin. If PORTxn is written logic one when the pin is configured as an input pin, the pull-up resistor is activated. To switch the pull-up resistor off, PORTxn has to be written logic zero or the pin has to be configured as an output pin. The port pins are tri-stated when reset condition becomes active, even if no clocks are running. If PORTxn is written logic one when the pin is configured as an output pin, the port pin is driven high (one). If PORTxn is written logic zero when the pin is configured as an output pin, the port pin is driven low (zero). clk RPx RRx RDx WDx PUD SYNCHRONIZER WDx: WRITE DDRx WRx: WRITE PORTx RRx: READ PORTx REGISTER RPx: READ PORTx PIN PUD: PULLUP DISABLE clkI/O: I/O CLOCK RDx: READ DDRx D L Q Q RESET RESET Q D Q Q Q D CLR PORTxn Q Q D CLR DDxn PINxn DATA BUS SLEEP SLEEP: SLEEP CONTROL Pxn I/O WPx 0 1 WRx WPx: WRITE PINx REGISTER57 8246B–AVR–09/11 ATtiny2313A/4313 10.1.2 Toggling the Pin Writing a logic one to PINxn toggles the value of PORTxn, independent on the value of DDRxn. Note that the SBI instruction can be used to toggle one single bit in a port. 10.1.3 Switching Between Input and Output When switching between tri-state ({DDxn, PORTxn} = 0b00) and output high ({DDxn, PORTxn} = 0b11), an intermediate state with either pull-up enabled {DDxn, PORTxn} = 0b01) or output low ({DDxn, PORTxn} = 0b10) must occur. Normally, the pull-up enabled state is fully acceptable, as a high-impedant environment will not notice the difference between a strong high driver and a pull-up. If this is not the case, the PUD bit in the MCUCR Register can be set to disable all pull-ups in all ports. Switching between input with pull-up and output low generates the same problem. The user must use either the tri-state ({DDxn, PORTxn} = 0b00) or the output high state ({DDxn, PORTxn} = 0b10) as an intermediate step. Table 10-1 summarizes the control signals for the pin value. 10.1.4 Reading the Pin Value Independent of the setting of Data Direction bit DDxn, the port pin can be read through the PINxn Register bit. As shown in Figure 10-2 on page 56, the PINxn Register bit and the preceding latch constitute a synchronizer. This is needed to avoid metastability if the physical pin changes value near the edge of the internal clock, but it also introduces a delay. Figure 10-3 shows a timing diagram of the synchronization when reading an externally applied pin value. The maximum and minimum propagation delays are denoted tpd,max and tpd,min respectively. Figure 10-3. Synchronization when Reading an Externally Applied Pin value Table 10-1. Port Pin Configurations DDxn PORTxn PUD (in MCUCR) I/O Pull-up Comment 0 0 X Input No Tri-state (Hi-Z) 0 1 0 Input Yes Pxn will source current if ext. pulled low 0 1 1 Input No Tri-state (Hi-Z) 1 0 X Output No Output Low (Sink) 1 1 X Output No Output High (Source) XXX in r17, PINx 0x00 0xFF INSTRUCTIONS SYNC LATCH PINxn r17 XXX SYSTEM CLK tpd, max tpd, min58 8246B–AVR–09/11 ATtiny2313A/4313 Consider the clock period starting shortly after the first falling edge of the system clock. The latch is closed when the clock is low, and goes transparent when the clock is high, as indicated by the shaded region of the “SYNC LATCH” signal. The signal value is latched when the system clock goes low. It is clocked into the PINxn Register at the succeeding positive clock edge. As indicated by the two arrows tpd,max and tpd,min, a single signal transition on the pin will be delayed between ½ and 1½ system clock period depending upon the time of assertion. When reading back a software assigned pin value, a nop instruction must be inserted as indicated in Figure 10-4 on page 58. The out instruction sets the “SYNC LATCH” signal at the positive edge of the clock. In this case, the delay tpd through the synchronizer is one system clock period. Figure 10-4. Synchronization when Reading a Software Assigned Pin Value 10.1.5 Digital Input Enable and Sleep Modes As shown in Figure 10-2 on page 56, the digital input signal can be clamped to ground at the input of the schmitt-trigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep Controller in Power-down and Standby modes to avoid high power consumption if some input signals are left floating, or have an analog signal level close to VCC/2. SLEEP is overridden for port pins enabled as external interrupt pins. If the external interrupt request is not enabled, SLEEP is active also for these pins. SLEEP is also overridden by various other alternate functions as described in “Alternate Port Functions” on page 60. If a logic high level (“one”) is present on an asynchronous external interrupt pin configured as “Interrupt on Rising Edge, Falling Edge, or Any Logic Change on Pin” while the external interrupt is not enabled, the corresponding External Interrupt Flag will be set when resuming from the above mentioned Sleep mode, as the clamping in these sleep mode produces the requested logic change. 10.1.6 Unconnected Pins If some pins are unused, it is recommended to ensure that these pins have a defined level. Even though most of the digital inputs are disabled in the deep sleep modes as described above, floating inputs should be avoided to reduce current consumption in all other modes where the digital inputs are enabled (Reset, Active mode and Idle mode). The simplest method to ensure a defined level of an unused pin, is to enable the internal pull-up. In this case, the pull-up will be disabled during reset. If low power consumption during reset is out PORTx, r16 nop in r17, PINx 0xFF 0x00 0xFF SYSTEM CLK r16 INSTRUCTIONS SYNC LATCH PINxn r17 t pd59 8246B–AVR–09/11 ATtiny2313A/4313 important, it is recommended to use an external pull-up or pulldown. Connecting unused pins directly to VCC or GND is not recommended, since this may cause excessive currents if the pin is accidentally configured as an output. 10.1.7 Program Examples The following code example shows how to set port A pins 0 and 1 high, 2 and 3 low, and define the port pins from 4 to 7 as input with a pull-up assigned to port pin 4. The resulting pin values are read back again, but as previously discussed, a nop instruction is included to be able to read back the value recently assigned to some of the pins. Note: Two temporary registers are used to minimize the time from pull-ups are set on pins 0, 1 and 4, until the direction bits are correctly set, defining bit 2 and 3 as low and redefining bits 0 and 1 as strong high drivers. Note: 1. See “Code Examples” on page 7. Assembly Code Example ... ; Define pull-ups and set outputs high ; Define directions for port pins ldi r16,(1< CSn2:0 > 1). The number of system clock cycles from when the timer is enabled to the first count occurs can be from 1 to N+1 system clock cycles, where N equals the prescaler divisor (8, 64, 256, or 1024). It is possible to use the prescaler reset for synchronizing the Timer/Counter to program execution. However, care must be taken if the other Timer/Counter that shares the same prescaler also uses prescaling. A prescaler reset will affect the prescaler period for all Timer/Counters it is connected to. 13.3 External Clock Source An external clock source applied to the T1/T0 pin can be used as Timer/Counter clock (clkT1/clkT0). The T1/T0 pin is sampled once every system clock cycle by the pin synchronization logic. The synchronized (sampled) signal is then passed through the edge detector. Figure 13-1 shows a functional equivalent block diagram of the T1/T0 synchronization and edge detector logic. The registers are clocked at the positive edge of the internal system clock (clkI/O). The latch is transparent in the high period of the internal system clock. The edge detector generates one clkT1/clkT0 pulse for each positive (CSn2:0 = 7) or negative (CSn2:0 = 6) edge it detects. Figure 13-1. T1/T0 Pin Sampling The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles from an edge has been applied to the T1/T0 pin to the counter is updated. Tn_sync (To Clock Select Logic) Synchronization Edge Detector D Q D Q LE Tn D Q clkI/O119 8246B–AVR–09/11 ATtiny2313A/4313 Enabling and disabling of the clock input must be done when T1/T0 has been stable for at least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated. Each half period of the external clock applied must be longer than one system clock cycle to ensure correct sampling. The external clock must be guaranteed to have less than half the system clock frequency (fExtClk < fclk_I/O/2) given a 50/50% duty cycle. Since the edge detector uses sampling, the maximum frequency of an external clock it can detect is half the sampling frequency (Nyquist sampling theorem). However, due to variation of the system clock frequency and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is recommended that maximum frequency of an external clock source is less than fclk_I/O/2.5. An external clock source can not be prescaled. Figure 13-2. Prescaler for Timer/Counter0 and Timer/Counter1(1) Note: 1. The synchronization logic on the input pins (T1/T0) is shown in Figure 13-1 on page 118. 13.4 Register Description 13.4.1 GTCCR – General Timer/Counter Control Register • Bits 7..1 – Res: Reserved Bits These bits are reserved bits in the ATtiny2313A/4313 and will always read as zero. • Bit 0 – PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0 When this bit is one, Timer/Counter1 and Timer/Counter0 prescaler will be Reset. This bit is normally cleared immediately by hardware. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler and a reset of this prescaler will affect both timers. PSR10 Clear clkT1 clkT0 T1 T0 clkI/O Synchronization Synchronization Bit 7 6 5 4 3 2 1 0 0x23 (0x43) — — — — — — — PSR10 GTCCR Read/Write R R R R R R R R/W Initial Value 0 0 0 0 0 0 0 0120 8246B–AVR–09/11 ATtiny2313A/4313 14. USART 14.1 Features • Full Duplex Operation (Independent Serial Receive and Transmit Registers) • Asynchronous or Synchronous Operation • Master or Slave Clocked Synchronous Operation • High Resolution Baud Rate Generator • Supports Serial Frames with 5, 6, 7, 8, or 9 Data Bits and 1 or 2 Stop Bits • Odd or Even Parity Generation and Parity Check Supported by Hardware • Data OverRun Detection • Framing Error Detection • Noise Filtering Includes False Start Bit Detection and Digital Low Pass Filter • Three Separate Interrupts on TX Complete, TX Data Register Empty and RX Complete • Multi-processor Communication Mode • Double Speed Asynchronous Communication Mode 14.2 Overview The Universal Synchronous and Asynchronous serial Receiver and Transmitter (USART) is a highly flexible serial communication device. A simplified block diagram of the USART Transmitter is shown in Figure 14-1. CPU accessible I/O Registers and I/O pins are shown in bold. Figure 14-1. USART Block Diagram(1) Note: 1. Refer to Figure 1-1 on page 2, Table 10-9 on page 68, and Table 10-6 on page 66 for USART pin placement. PARITY GENERATOR UBRR[H:L] UDR (Transmit) UCSRA UCSRB UCSRC BAUD RATE GENERATOR TRANSMIT SHIFT REGISTER RECEIVE SHIFT REGISTER RxD TxD PIN CONTROL UDR (Receive) PIN CONTROL XCK DATA RECOVERY CLOCK RECOVERY PIN CONTROL TX CONTROL RX CONTROL PARITY CHECKER DATA BUS OSC SYNC LOGIC Clock Generator Transmitter Receiver121 8246B–AVR–09/11 ATtiny2313A/4313 The dashed boxes in the block diagram separate the three main parts of the USART (listed from the top): Clock Generator, Transmitter and Receiver. Control registers are shared by all units. The Clock Generation logic consists of synchronization logic for external clock input used by synchronous slave operation, and the baud rate generator. The XCK (Transfer Clock) pin is only used by synchronous transfer mode. The Transmitter consists of a single write buffer, a serial Shift Register, Parity Generator and Control logic for handling different serial frame formats. The write buffer allows a continuous transfer of data without any delay between frames. The Receiver is the most complex part of the USART module due to its clock and data recovery units. The recovery units are used for asynchronous data reception. In addition to the recovery units, the Receiver includes a Parity Checker, Control logic, a Shift Register and a two level receive buffer (UDR). The Receiver supports the same frame formats as the Transmitter, and can detect Frame Error, Data OverRun and Parity Errors. 14.2.1 AVR USART vs. AVR UART – Compatibility The USART is fully compatible with the AVR UART regarding: • Bit locations inside all USART Registers. • Baud Rate Generation. • Transmitter Operation. • Transmit Buffer Functionality. • Receiver Operation. However, the receive buffering has two improvements that will affect the compatibility in some special cases: • A second Buffer Register has been added. The two Buffer Registers operate as a circular FIFO buffer. Therefore the UDR must only be read once for each incoming data! More important is the fact that the error flags (FE and DOR) and the ninth data bit (RXB8) are buffered with the data in the receive buffer. Therefore the status bits must always be read before the UDR Register is read. Otherwise the error status will be lost since the buffer state is lost. • The Receiver Shift Register can now act as a third buffer level. This is done by allowing the received data to remain in the serial Shift Register (see Figure 14-1) if the Buffer Registers are full, until a new start bit is detected. The USART is therefore more resistant to Data OverRun (DOR) error conditions. The following control bits have changed name, but have same functionality and register location: • CHR9 is changed to UCSZ2. • OR is changed to DOR. 14.3 Clock Generation The Clock Generation logic generates the base clock for the Transmitter and Receiver. The USART supports four modes of clock operation: Normal asynchronous, Double Speed asynchronous, Master synchronous and Slave synchronous mode. The UMSEL bit in USART Control and Status Register C (UCSRC) selects between asynchronous and synchronous operation. Double Speed (asynchronous mode only) is controlled by the U2X found in the UCSRA Register. When using synchronous mode (UMSEL = 1), the Data Direction Register for the XCK122 8246B–AVR–09/11 ATtiny2313A/4313 pin (DDR_XCK) controls whether the clock source is internal (Master mode) or external (Slave mode). The XCK pin is only active when using synchronous mode. Figure 14-2 shows a block diagram of the clock generation logic. Figure 14-2. Clock Generation Logic, Block Diagram Signal description: txclk Transmitter clock (Internal Signal). rxclk Receiver base clock (Internal Signal). xcki Input from XCK pin (internal Signal). Used for synchronous slave operation. xcko Clock output to XCK pin (Internal Signal). Used for synchronous master operation. fosc XTAL pin frequency (System Clock). 14.3.1 Internal Clock Generation – The Baud Rate Generator Internal clock generation is used for the asynchronous and the synchronous master modes of operation. The description in this section refers to Figure 14-2. The USART Baud Rate Register (UBRR) and the down-counter connected to it function as a programmable prescaler or baud rate generator. The down-counter, running at system clock (fosc), is loaded with the UBRR value each time the counter has counted down to zero or when the UBRRL Register is written. A clock is generated each time the counter reaches zero. This clock is the baud rate generator clock output (= fosc/(UBRR+1)). The Transmitter divides the baud rate generator clock output by 2, 8 or 16 depending on mode. The baud rate generator output is used directly by the Receiver’s clock and data recovery units. However, the recovery units use a state machine that uses 2, 8 or 16 states depending on mode set by the state of the UMSEL, U2X and DDR_XCK bits. Table 14-1 contains equations for calculating the baud rate (in bits per second) and for calculating the UBRR value for each mode of operation using an internally generated clock source. Prescaling Down-Counter /2 UBRR /4 /2 fosc UBRR+1 Sync Register OSC XCK Pin txclk U2X UMSEL DDR_XCK 0 1 0 1 xcki xcko DDR_XCK rxclk 0 1 1 0 Edge Detector UCPOL123 8246B–AVR–09/11 ATtiny2313A/4313 Note: 1. The baud rate is defined to be the transfer rate in bit per second (bps) BAUD Baud rate (in bits per second, bps) fOSC System Oscillator clock frequency UBRR Contents of the UBRRH and UBRRL Registers, (0-4095) Some examples of UBRR values for some system clock frequencies are found in Table 14-9 (see page 142). 14.3.2 Double Speed Operation (U2X) The transfer rate can be doubled by setting the U2X bit in UCSRA. Setting this bit only has effect for the asynchronous operation. Set this bit to zero when using synchronous operation. Setting this bit will reduce the divisor of the baud rate divider from 16 to 8, effectively doubling the transfer rate for asynchronous communication. Note however that the Receiver will in this case only use half the number of samples (reduced from 16 to 8) for data sampling and clock recovery, and therefore a more accurate baud rate setting and system clock are required when this mode is used. For the Transmitter, there are no downsides. 14.3.3 External Clock External clocking is used by the synchronous slave modes of operation. The description in this section refers to Figure 14-2 for details. External clock input from the XCK pin is sampled by a synchronization register to minimize the chance of meta-stability. The output from the synchronization register must then pass through an edge detector before it can be used by the Transmitter and Receiver. This process introduces a two CPU clock period delay and therefore the maximum external XCK clock frequency is limited by the following equation: Note that fosc depends on the stability of the system clock source. It is therefore recommended to add some margin to avoid possible loss of data due to frequency variations. Table 14-1. Equations for Calculating Baud Rate Register Setting Operating Mode Equation for Calculating Baud Rate(1) Equation for Calculating UBRR Value Asynchronous Normal mode (U2X = 0) Asynchronous Double Speed mode (U2X = 1) Synchronous Master mode BAUD f OSC 16( ) UBRR + 1 = -------------------------------------- UBRR f OSC 16BAUD = ------------------------ – 1 BAUD f OSC 8( ) UBRR + 1 = ----------------------------------- UBRR f OSC 8BAUD = -------------------- – 1 BAUD f OSC 2( ) UBRR + 1 = ----------------------------------- UBRR f OSC 2BAUD = -------------------- – 1 f XCK f OSC 4 < -----------124 8246B–AVR–09/11 ATtiny2313A/4313 14.3.4 Synchronous Clock Operation When synchronous mode is used (UMSEL = 1), the XCK pin will be used as either clock input (Slave) or clock output (Master). The dependency between the clock edges and data sampling or data change is the same. The basic principle is that data input (on RxD) is sampled at the opposite XCK clock edge of the edge the data output (TxD) is changed. Figure 14-3. Synchronous Mode XCK Timing. The UCPOL bit UCRSC selects which XCK clock edge is used for data sampling and which is used for data change. As Figure 14-3 shows, when UCPOL is zero the data will be changed at rising XCK edge and sampled at falling XCK edge. If UCPOL is set, the data will be changed at falling XCK edge and sampled at rising XCK edge. 14.4 Frame Formats A serial frame is defined to be one character of data bits with synchronization bits (start and stop bits), and optionally a parity bit for error checking. The USART accepts all 30 combinations of the following as valid frame formats: • 1 start bit • 5, 6, 7, 8, or 9 data bits • no, even or odd parity bit • 1 or 2 stop bits A frame starts with the start bit followed by the least significant data bit. Then the next data bits, up to a total of nine, are succeeding, ending with the most significant bit. If enabled, the parity bit is inserted after the data bits, before the stop bits. When a complete frame is transmitted, it can be directly followed by a new frame, or the communication line can be set to an idle (high) state. Figure 14-4 illustrates the possible combinations of the frame formats. Bits inside brackets are optional. Figure 14-4. Frame Formats RxD / TxD XCK RxD / TxD UCPOL = 0 XCK UCPOL = 1 Sample Sample (IDLE) St Sp1 [Sp2] 0 2 3 4 [5] [6] [7] [8] [P] 1 (St / IDLE) FRAME125 8246B–AVR–09/11 ATtiny2313A/4313 St Start bit, always low. (n) Data bits (0 to 8). P Parity bit. Can be odd or even. Sp Stop bit, always high. IDLE No transfers on the communication line (RxD or TxD). An IDLE line must be high. The frame format used by the USART is set by the UCSZ2:0, UPM1:0 and USBS bits in UCSRB and UCSRC. The Receiver and Transmitter use the same setting. Note that changing the setting of any of these bits will corrupt all ongoing communication for both the Receiver and Transmitter. The USART Character SiZe (UCSZ2:0) bits select the number of data bits in the frame. The USART Parity mode (UPM1:0) bits enable and set the type of parity bit. The selection between one or two stop bits is done by the USART Stop Bit Select (USBS) bit. The Receiver ignores the second stop bit. An FE (Frame Error) will therefore only be detected in the cases where the first stop bit is zero. 14.4.1 Parity Bit Calculation The parity bit is calculated by doing an exclusive-or of all the data bits. If odd parity is used, the result of the exclusive or is inverted. The relation between the parity bit and data bits is as follows: Peven Parity bit using even parity Podd Parity bit using odd parity dn Data bit n of the character If used, the parity bit is located between the last data bit and first stop bit of a serial frame. 14.5 USART Initialization The USART has to be initialized before any communication can take place. The initialization process normally consists of setting the baud rate, setting frame format and enabling the Transmitter or the Receiver depending on the usage. For interrupt driven USART operation, the Global Interrupt Flag should be cleared (and interrupts globally disabled) when doing the initialization. Before doing a re-initialization with changed baud rate or frame format, be sure that there are no ongoing transmissions during the period the registers are changed. The TXC flag can be used to check that the Transmitter has completed all transfers, and the RXC flag can be used to check that there are no unread data in the receive buffer. Note that the TXC flag must be cleared before each transmission (before UDR is written) if it is used for this purpose. Peven dn – 1 … d3 d2 d1 d0 0 Podd ⊕⊕⊕⊕⊕⊕ dn – 1 … d3 d2 d1 d0 ⊕⊕⊕⊕⊕⊕ 1 = =126 8246B–AVR–09/11 ATtiny2313A/4313 The following simple USART initialization code examples show one assembly and one C function that are equal in functionality. The examples assume asynchronous operation using polling (no interrupts enabled) and a fixed frame format. The baud rate is given as a function parameter. For the assembly code, the baud rate parameter is assumed to be stored in the r17:r16 Registers. Note: 1. See “Code Examples” on page 7. More advanced initialization routines can be made that include frame format as parameters, disable interrupts and so on. However, many applications use a fixed setting of the baud and control registers, and for these types of applications the initialization code can be placed directly in the main routine, or be combined with initialization code for other I/O modules. 14.6 Data Transmission – The USART Transmitter The USART Transmitter is enabled by setting the Transmit Enable (TXEN) bit in the UCSRB Register. When the Transmitter is enabled, the normal port operation of the TxD pin is overridden by the USART and given the function as the Transmitter’s serial output. The baud rate, mode of operation and frame format must be set up once before doing any transmissions. If synchronous operation is used, the clock on the XCK pin will be overridden and used as transmission clock. Assembly Code Example(1) USART_Init: ; Set baud rate out UBRRH, r17 out UBRRL, r16 ; Enable receiver and transmitter ldi r16, (1<>8); UBRRL = (unsigned char)baud; /* Enable receiver and transmitter */ UCSRB = (1<> 1) & 0x01; return ((resh << 8) | resl); }132 8246B–AVR–09/11 ATtiny2313A/4313 The receive function example reads all the I/O Registers into the Register File before any computation is done. This gives an optimal receive buffer utilization since the buffer location read will be free to accept new data as early as possible. 14.7.3 Receive Compete Flag and Interrupt The USART Receiver has one flag that indicates the Receiver state. The Receive Complete (RXC) flag indicates if there are unread data present in the receive buffer. This flag is one when unread data exist in the receive buffer, and zero when the receive buffer is empty (i.e., does not contain any unread data). If the Receiver is disabled (RXEN = 0), the receive buffer will be flushed and consequently the RXC bit will become zero. When the Receive Complete Interrupt Enable (RXCIE) in UCSRB is set, the USART Receive Complete interrupt will be executed as long as the RXC flag is set (provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDR in order to clear the RXC flag, otherwise a new interrupt will occur once the interrupt routine terminates. 14.7.4 Receiver Error Flags The USART Receiver has three error flags: Frame Error (FE), Data OverRun (DOR) and Parity Error (UPE). All can be accessed by reading UCSRA. Common for the error flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the error flags, the UCSRA must be read before the receive buffer (UDR), since reading the UDR I/O location changes the buffer read location. Another equality for the error flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRA is written for upward compatibility of future USART implementations. None of the error flags can generate interrupts. The Frame Error (FE) flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FE flag is zero when the stop bit was correctly read (as one), and the FE flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FE flag is not affected by the setting of the USBS bit in UCSRC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRA. The Data OverRun (DOR) flag indicates data loss due to a receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DOR flag is set there was one or more serial frame lost between the frame last read from UDR, and the next frame read from UDR. For compatibility with future devices, always write this bit to zero when writing to UCSRA. The DOR flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (UPE) Flag indicates that the next frame in the receive buffer had a Parity Error when received. If Parity Check is not enabled the UPE bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRA. For more details see “Parity Bit Calculation” on page 125 and “Parity Checker” on page 132. 14.7.5 Parity Checker The Parity Checker is active when the high USART Parity mode (UPM1) bit is set. Type of Parity Check to be performed (odd or even) is selected by the UPM0 bit. When enabled, the Parity133 8246B–AVR–09/11 ATtiny2313A/4313 Checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error (UPE) flag can then be read by software to check if the frame had a Parity Error. The UPE bit is set if the next character that can be read from the receive buffer had a Parity Error when received and the Parity Checking was enabled at that point (UPM1 = 1). This bit is valid until the receive buffer (UDR) is read. 14.7.6 Disabling the Receiver In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing receptions will therefore be lost. When disabled (i.e., the RXEN is set to zero) the Receiver will no longer override the normal function of the RxD port pin. The Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in the buffer will be lost 14.7.7 Flushing the Receive Buffer The receiver buffer FIFO will be flushed when the Receiver is disabled, i.e., the buffer will be emptied of its contents. Unread data will be lost. If the buffer has to be flushed during normal operation, due to for instance an error condition, read the UDR I/O location until the RXC flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See “Code Examples” on page 7. 14.8 Asynchronous Data Reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxD pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the Receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. 14.8.1 Asynchronous Clock Recovery The clock recovery logic synchronizes internal clock to the incoming serial frames. Figure 14-5 illustrates the sampling process of the start bit of an incoming frame. The sample rate is 16 times Assembly Code Example(1) USART_Flush: sbis UCSRA, RXC ret in r16, UDR rjmp USART_Flush C Code Example(1) void USART_Flush( void ) { unsigned char dummy; while ( UCSRA & (1< MSB MSB 6 5 4 3 2 1 LSB 1 2 3 4 5 6 7 8 6 5 4 3 2 1 LSB USCK USCK DO DI A B C D E CYCLE ( Reference )159 8246B–AVR–09/11 ATtiny2313A/4313 SPITransfer_loop: out USICR,r17 in r16, USISR sbrs r16, USIOIF rjmp SPITransfer_loop in r16,USIDR ret The code is size optimized using only eight instructions (plus return). The code example assumes that the DO and USCK pins have been enabled as outputs in DDRA. The value stored in register r16 prior to the function is called is transferred to the slave device, and when the transfer is completed the data received from the slave is stored back into the register r16. The second and third instructions clear the USI Counter Overflow Flag and the USI counter value. The fourth and fifth instructions set three-wire mode, positive edge clock, count at USITC strobe, and toggle USCK. The loop is repeated 16 times. The following code demonstrates how to use the USI as an SPI master with maximum speed (fSCK = fCK/2): SPITransfer_Fast: out USIDR,r16 ldi r16,(1< 2 CPU clock cycles – When fck >= 12MHz: 3 CPU clock cycles • Minimum high period of serial clock: – When fck < 12MHz: > 2 CPU clock cycles – When fck >= 12MHz: 3 CPU clock cycles VCC GND XTAL1 SCK MISO MOSI RESET +1.8 - 5.5V195 8246B–AVR–09/11 ATtiny2313A/4313 21.3.1 Pin Mapping The pin mapping is listed in Table 21-7. Note that not all parts use the SPI pins dedicated for the internal SPI interface. 21.3.2 Programming Algorithm When writing serial data to the ATtiny2313A/4313, data is clocked on the rising edge of SCK. When reading data from the ATtiny2313A/4313, data is clocked on the falling edge of SCK. See Figure 22-6 on page 205 and Figure 22-7 on page 205 for timing details. To program and verify the ATtiny2313A/4313 in the serial programming mode, the following sequence is recommended (See Table 21-8, “Serial Programming Instruction Set,” on page 196): 1. Power-up sequence: apply power between VCC and GND while RESET and SCK are set to “0” – In some systems, the programmer can not guarantee that SCK is held low during power-up. In this case, RESET must be given a positive pulse after SCK has been set to '0'. The duration of the pulse must be at least tRST plus two CPU clock cycles. See Table 22-3 on page 201 for definition of minimum pulse width on RESET pin, tRST 2. Wait for at least 20 ms and then enable serial programming by sending the Programming Enable serial instruction to the MOSI pin 3. The serial programming instructions will not work if the communication is out of synchronization. When in sync, the second byte (0x53) will echo back when issuing the third byte of the Programming Enable instruction – Regardless if the echo is correct or not, all four bytes of the instruction must be transmitted – If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command 4. The Flash is programmed one page at a time. The memory page is loaded one byte at a time by supplying the 4 LSB of the address and data together with the Load Program Memory Page instruction. – To ensure correct loading of the page, the data low byte must be loaded before data high byte is applied for a given address – The Program Memory Page is stored by loading the Write Program Memory Page instruction with the 6 MSB of the address – If polling (RDY/BSY) is not used, the user must wait at least tWD_FLASH before issuing the next page. (See Table 21-9 on page 197). Accessing the serial programming interface before the Flash write operation completes can result in incorrect programming. 5. The EEPROM can be programmed one byte or one page at a time. Table 21-7. Pin Mapping Serial Programming Symbol Pins I/O Description MOSI PB5 I Serial Data in MISO PB6 O Serial Data out SCK PB7 I Serial Clock196 8246B–AVR–09/11 ATtiny2313A/4313 – A: Byte programming. The EEPROM array is programmed one byte at a time by supplying the address and data together with the Write instruction. EEPROM memory locations are automatically erased before new data is written. If polling (RDY/BSY) is not used, the user must wait at least tWD_EEPROM before issuing the next byte (See Table 21-9). In a chip erased device, no 0xFFs in the data file(s) need to be programmed – B: Page programming (the EEPROM array is programmed one page at a time). The memory page is loaded one byte at a time by supplying the 6 LSB of the address and data together with the Load EEPROM Memory Page instruction. The EEPROM memory page is stored by loading the Write EEPROM Memory Page Instruction with the 7 MSB of the address. When using EEPROM page access only byte locations loaded with the Load EEPROM Memory Page instruction are altered and the remaining locations remain unchanged. If polling (RDY/BSY) is not used, the user must wait at least tWD_EEPROM before issuing the next byte (See Table 21-9). In a chip erased device, no 0xFF in the data file(s) need to be programmed 6. Any memory location can be verified by using the Read instruction, which returns the content at the selected address at the serial output pin (MISO) 7. At the end of the programming session, RESET can be set high to commence normal operation 8. Power-off sequence (if required): set RESET to “1”, and turn VCC power off 21.3.3 Programming Instruction Set The instruction set for serial programming is described in Table 21-8. Table 21-8. Serial Programming Instruction Set Instruction Instruction Format Byte 1 Byte 2 Byte 3 Byte4 Operation Programming Enable 1010 1100 0101 0011 xxxx xxxx xxxx xxxx Enable Serial Programming after RESET goes low. Chip Erase 1010 1100 100x xxxx xxxx xxxx xxxx xxxx Chip Erase EEPROM and Flash. Read Program Memory 0010 H000 0000 00aa bbbb bbbb oooo oooo Read H (high or low) data o from Program memory at word address a:b. Load Program Memory Page 0100 H000 000x xxxx xxxx bbbb iiii iiii Write H (high or low) data i to Program Memory page at word address b. Data low byte must be loaded before Data high byte is applied within the same address. Write Program Memory Page 0100 1100 0000 00aa bbbb xxxx xxxx xxxx Write Program Memory Page at address a:b. Read EEPROM Memory 1010 0000 000x xxxx xbbb bbbb oooo oooo Read data o from EEPROM memory at address b. Write EEPROM Memory 1100 0000 000x xxxx xbbb bbbb iiii iiii Write data i to EEPROM memory at address b. Load EEPROM Memory Page (page access) 1100 0001 0000 0000 0000 00bb iiii iiii Load data i to EEPROM memory page buffer. After data is loaded, program EEPROM page.197 8246B–AVR–09/11 ATtiny2313A/4313 Note: a = address high bits, b = address low bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care If the LSB of RDY/BSY data byte out is ‘1’, a programming operation is still pending. Wait until this bit returns ‘0’ before the next instruction is carried out. Within the same page, the low data byte must be loaded prior to the high data byte. After data is loaded to the page buffer, program the EEPROM page. 21.4 Programming Time for Flash and EEPROM Flash and EEPROM wait times are listed in Table 21-9. Write EEPROM Memory Page (page access) 1100 0010 00xx xxxx xbbb bb00 xxxx xxxx Write EEPROM page at address b. Read Lock bits 0101 1000 0000 0000 xxxx xxxx xxoo oooo Read Lock bits. “0” = programmed, “1” = unprogrammed. See Table 20-1 on page 178 for details. Write Lock bits 1010 1100 111x xxxx xxxx xxxx 11ii iiii Write Lock bits. Set bits = “0” to program Lock bits. See Table 20-1 on page 178 for details. Read Signature Byte 0011 0000 000x xxxx xxxx xxbb oooo oooo Read Signature Byte o at address b. Write Fuse bits 1010 1100 1010 0000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. Write Fuse High bits 1010 1100 1010 1000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. Write Extended Fuse Bits 1010 1100 1010 0100 xxxx xxxx xxxx xxxi Set bits = “0” to program, “1” to unprogram. Read Fuse bits 0101 0000 0000 0000 xxxx xxxx oooo oooo Read Fuse bits. “0” = programmed, “1” = unprogrammed. Read Fuse High bits 0101 1000 0000 1000 xxxx xxxx oooo oooo Read Fuse High bits. “0” = programmed, “1” = unprogrammed. Read Extended Fuse Bits 0101 0000 0000 1000 xxxx xxxx oooo oooo Read Extended Fuse bits. “0” = programmed, “1” = unprogrammed. Read Calibration Byte 0011 1000 000x xxxx 0000 000b oooo oooo Read Calibration Byte at address b. Poll RDY/BSY 1111 0000 0000 0000 xxxx xxxx xxxx xxxo If o = “1”, a programming operation is still busy. Wait until this bit returns to “0” before applying another command. Table 21-8. Serial Programming Instruction Set Instruction Instruction Format Byte 1 Byte 2 Byte 3 Byte4 Operation Table 21-9. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location Symbol Minimum Wait Delay tWD_FLASH 4.5 ms tWD_EEPROM 4.0 ms tWD_ERASE 9.0 ms tWD_FUSE 4.5 ms198 8246B–AVR–09/11 ATtiny2313A/4313 22. Electrical Characteristics 22.1 Absolute Maximum Ratings* 22.2 DC Characteristics Operating Temperature.................................. -55°C to +125°C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ............................................... 40.0 mA DC Current VCC and GND Pins................................ 200.0 mA TA = -40°C to 85°C, VCC = 1.8V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min. Typ. Max. Units VIL Input Low Voltage except XTAL1 and RESET pin VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V -0.5 0.2VCC 0.3VCC V VIH Input High-voltage except XTAL1 and RESET pins VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.7VCC (1) 0.6VCC (1) VCC +0.5 (2) V VIL1 Input Low Voltage XTAL1 pin VCC = 1.8V - 5.5V -0.5 0.1VCC V VIH1 Input High-voltage XTAL1 pin VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.8VCC (1) 0.7VCC (1) VCC +0.5 (2) V VIL2 Input Low Voltage RESET pin VCC = 1.8V - 5.5V -0.5 0.2VCC V VIH2 Input High-voltage RESET pin VCC = 1.8V - 5.5V 0.9VCC (1) VCC +0.5 (2) V VIL3 Input Low Voltage RESET pin as I/O VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V -0.5 0.2VCC 0.3VCC V VIH3 Input High-voltage RESET pin as I/O VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.7VCC (1) 0.6VCC (1) VCC +0.5 (2) V VOL Output Low Voltage(3) (Except Reset Pin)(5) IOL = 20 mA, VCC = 5V IOL = 10mA, VCC = 3V 0.8 0.6 V V VOH Output High-voltage(4) (Except Reset Pin)(5) IOH = -20 mA, VCC = 5V IOH = -10 mA, VCC = 3V 4.2 2.4 V V I IL Input Leakage Current I/O Pin VCC = 5.5V, pin low (absolute value) 1(6) µA IIH Input Leakage Current I/O Pin VCC = 5.5V, pin high (absolute value) 1(6) µA RRST Reset Pull-up Resistor 30 60 kΩ Rpu I/O Pin Pull-up Resistor 20 50 kΩ199 8246B–AVR–09/11 ATtiny2313A/4313 Notes: 1. “Min” means the lowest value where the pin is guaranteed to be read as high. 2. “Max” means the highest value where the pin is guaranteed to be read as low. 3. Although each I/O port can sink more than the test conditions (20 mA at VCC = 5V, 10 mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed: 1] The sum of all IOL, for all ports, should not exceed 60 mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20 mA at VCC = 5V, 10 mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed: 1] The sum of all IOH, for all ports, should not exceed 60 mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 5. The RESET pin must tolerate high voltages when entering and operating in programming modes and, as a consequence, has a weak drive strength as compared to regular I/O pins. See Figure 23-29 and Figure 23-30. 6. These are test limits, which account for leakage currents of the test environment. Actual device leakage currents are lower. 7. Values using methods described in “Minimizing Power Consumption” on page 36. Power Reduction is enabled (PRR = 0xFF), the external clock is selected (CKSEL = 0000), and there is no I/O drive. 8. BOD Disabled. I CC Power Supply Current Active 1MHz, VCC = 2V(7) 0.2 0.55 mA Active 4MHz, VCC = 3V(7) 1.3 2.5 mA Active 8MHz, VCC = 5V(7) 3.9 7 mA Idle 1MHz, VCC = 2V(7) 0.03 0.15 mA Idle 4MHz, VCC = 3V(7) 0.25 0.6 mA Idle 8MHz, VCC = 5V(7) 1 2 mA Power-down mode WDT enabled, VCC = 3V(8) 4 10 µA WDT disabled, VCC = 3V(8) < 0.15 2 µA TA = -40°C to 85°C, VCC = 1.8V to 5.5V (unless otherwise noted) (Continued) Symbol Parameter Condition Min. Typ. Max. Units200 8246B–AVR–09/11 ATtiny2313A/4313 22.3 Speed The maximum operating frequency of the device is dependent on supply voltage, VCC . The relationship between supply voltage and maximum operating frequency is piecewise linear, as shown in Figure 22-1. Figure 22-1. Maximum Frequency vs. VCC 22.4 Clock Characteristics 22.4.1 Calibrated Internal RC Oscillator Accuracy It is possible to manually calibrate the internal oscillator to be more accurate than default factory calibration. Note that the oscillator frequency depends on temperature and voltage. Voltage and temperature characteristics can be found in Figure 23-46 on page 229, and Figure 23-47 on page 230. Notes: 1. Accuracy of oscillator frequency at calibration point (fixed temperature and fixed voltage). 4 MHz 1.8V 5.5V 4.5V 20 MHz 2.7V 10 MHz Table 22-1. Calibration Accuracy of Internal RC Oscillator Calibration Method Target Frequency VCC Temperature Accuracy at given Voltage & Temperature(1) Factory Calibration 4.0 / 8.0MHz 3V 25°C ±10% User Calibration Fixed frequency within: 3.1 – 4.7 MHz / 7.3 – 9.1MHz Fixed voltage within: 1.8V – 5.5V Fixed temperature within: -40°C – 85°C ±2%201 8246B–AVR–09/11 ATtiny2313A/4313 22.4.2 External Clock Drive Figure 22-2. External Clock Drive Waveform 22.5 System and Reset Characteristics Notes: 1. When RESET pin used as reset (not as I/O). 2. Not tested in production. VIL1 VIH1 Table 22-2. External Clock Drive Symbol Parameter VCC = 1.8 - 5.5V VCC = 2.7 - 5.5V VCC = 4.5 - 5.5V Min. Max. Min. Max. Min. Max. Units 1/tCLCL Clock Frequency 0 4 0 10 0 20 MHz tCLCL Clock Period 250 100 50 ns tCHCX High Time 100 40 20 ns tCLCX Low Time 100 40 20 ns tCLCH Rise Time 2.0 1.6 0.5 µs tCHCL Fall Time 2.0 1.6 0.5 µs ΔtCLCL Change in period from one clock cycle to the next 2 2 2 % Table 22-3. Reset, Brown-out, and Internal Voltage Characteristics Symbol Parameter Condition Min Typ Max Units VRST RESET Pin Threshold Voltage 0.2 VCC 0.8VCC V t RST Minimum pulse width on RESET Pin (1)(2) VCC = 1.8 - 5.5V 2.5 µs VHYST Brown-out Detector Hysteresis (2) 50 mV tBOD Min Pulse Width on Brown-out Reset (2) 2 µs VBG Internal bandgap reference voltage VCC = 2.7V TA = 25°C 1.0 1.1 1.2 V tBG Internal bandgap reference start-up time (2) VCC = 2.7V TA = 25°C 40 70 µs IBG Internal bandgap reference current consumption (2) VCC = 2.7V TA = 25°C 15 µA202 8246B–AVR–09/11 ATtiny2313A/4313 22.5.1 Enhanced Power-On Reset Notes: 1. Values are guidelines, only. 2. Threshold where device is released from reset when voltage is rising. 3. The Power-on Reset will not work unless the supply voltage has been below VPOA. 22.5.2 Brown-Out Detection Note: 1. VBOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is tested down to VCC = VBOT during the production test. This guarantees that a Brown-out Reset will occur before VCC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. 22.6 Analog Comparator Characteristics Note: All parameters are based on simulation results and they are not tested in production Table 22-4. Characteristics of Enhanced Power-On Reset. TA = -40 – 85°C Symbol Parameter Min(1) Typ(1) Max(1) Units VPOR Release threshold of power-on reset (2) 1.1 1.4 1.6 V VPOA Activation threshold of power-on reset (3) 0.6 1.3 1.6 V SRON Power-On Slope Rate 0.01 V/ms Table 22-5. VBOT vs. BODLEVEL Fuse Coding BODLEVEL [1:0] Fuses Min(1) Typ(1) Max(1) Units 11 BOD Disabled 10 1.7 1.8 2.0 01 2.5 2.7 2.9 V 00 4.1 4.3 4.5 Table 22-6. Analog Comparator Characteristics, TA = -40°C - 85°C Symbol Parameter Condition Min Typ Max Units VACIO Input Offset Voltage VCC = 5V, VIN = VCC / 2 < 10 40 mV IACLK Input Leakage Current VCC = 5V, VIN = VCC / 2 -50 50 nA tACPD Analog Propagation Delay (from saturation to slight overdrive) VCC = 2.7V 750 ns VCC = 4.0V 500 Analog Propagation Delay (large step change) VCC = 2.7V 100 VCC = 4.0V 75 tDPD Digital Propagation Delay VCC = 1.8V - 5.5 1 2 CLK203 8246B–AVR–09/11 ATtiny2313A/4313 22.7 Parallel Programming Characteristics Notes: 1. tWLRH is valid for the Write Flash, Write EEPROM, Write Fuse bits and Write Lock bits commands. 2. tWLRH_CE is valid for the Chip Erase command. Table 22-7. Parallel Programming Characteristics, VCC = 5V ± 10% Symbol Parameter Min Typ Max Units VPP Programming Enable Voltage 11.5 12.5 V I PP Programming Enable Current 250 μA t DVXH Data and Control Valid before XTAL1 High 67 ns tXLXH XTAL1 Low to XTAL1 High 200 ns tXHXL XTAL1 Pulse Width High 150 ns tXLDX Data and Control Hold after XTAL1 Low 67 ns tXLWL XTAL1 Low to WR Low 0 ns tXLPH XTAL1 Low to PAGEL high 0 ns tPLXH PAGEL low to XTAL1 high 150 ns tBVPH BS1 Valid before PAGEL High 67 ns tPHPL PAGEL Pulse Width High 150 ns tPLBX BS1 Hold after PAGEL Low 67 ns tWLBX BS2/1 Hold after WR Low 67 ns tPLWL PAGEL Low to WR Low 67 ns tBVWL BS1 Valid to WR Low 67 ns tWLWH WR Pulse Width Low 150 ns tWLRL WR Low to RDY/BSY Low 0 1 μs t WLRH WR Low to RDY/BSY High(1) 3.7 4.5 ms tWLRH_CE WR Low to RDY/BSY High for Chip Erase(2) 7.5 9 ms tXLOL XTAL1 Low to OE Low 0 ns tBVDV BS1 Valid to DATA valid 0 1000 ns tOLDV OE Low to DATA Valid 1000 ns t OHDZ OE High to DATA Tri-stated 1000 ns204 8246B–AVR–09/11 ATtiny2313A/4313 Figure 22-3. Parallel Programming Timing, Including some General Timing Requirements Figure 22-4. Parallel Programming Timing, Loading Sequence with Timing Requirements(1) Note: 1. The timing requirements shown in Figure 22-3 (i.e., tDVXH, tXHXL, and tXLDX) also apply to loading operation. Figure 22-5. Parallel Programming Timing, Reading Sequence (within the Same Page) with Timing Requirements(1) Note: 1. The timing requirements shown in Figure 22-3 (i.e., tDVXH, tXHXL, and tXLDX) also apply to reading operation. Data & Contol (DATA, XA0/1, BS1, BS2) XTAL1 t XHXL t WLWH t DVXH t XLDX t PLWL t WLRH WR RDY/BSY PAGEL t PHPL t PLBX t BVPH t XLWL t WLBX tBVWL WLRL XTAL1 PAGEL t XLXH PLXH t t XLPH DATA ADDR0 (Low Byte) DATA (Low Byte) DATA (High Byte) ADDR1 (Low Byte) BS1 XA0 XA1 LOAD ADDRESS (LOW BYTE) LOAD DATA (LOW BYTE) LOAD DATA (HIGH BYTE) LOAD DATA LOAD ADDRESS (LOW BYTE) XTAL1 OE DATA ADDR0 (Low Byte) DATA (Low Byte) DATA (High Byte) ADDR1 (Low Byte) BS1 XA0 XA1 LOAD ADDRESS (LOW BYTE) READ DATA (LOW BYTE) READ DATA (HIGH BYTE) LOAD ADDRESS (LOW BYTE) t BVDV t OLDV t XLOL t OHDZ205 8246B–AVR–09/11 ATtiny2313A/4313 22.8 Serial Programming Characteristics Figure 22-6. Serial Programming Timing Note: 2 tCLCL for fck < 12 MHz, 3 tCLCL for fck >= 12 MHz Figure 22-7. Serial Programming Waveform Table 22-8. Serial Programming Characteristics, TA = -40°C to 85°C, VCC = 1.8 - 5.5V (Unless Otherwise Noted) Symbol Parameter Min Typ Max Units 1/tCLCL Oscillator Frequency (ATtiny2313A/4313) 0 4 MHz tCLCL Oscillator Period (ATtiny2313A/4313) 250 ns 1/tCLCL Oscillator Frequency (ATtiny2313A/4313, VCC = 4.5V - 5.5V) 0 20 MHz t CLCL Oscillator Period (ATtiny2313A/4313, VCC = 4.5V - 5.5V) 50 ns tSHSL SCK Pulse Width High 2 tCLCL* ns tSLSH SCK Pulse Width Low 2 tCLCL* ns tOVSH MOSI Setup to SCK High tCLCL ns t SHOX MOSI Hold after SCK High 2 tCLCL ns tSLIV SCK Low to MISO Valid 100 ns MOSI MISO SCK t OVSH t SHSL t t SHOX SLSH MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUT206 8246B–AVR–09/11 ATtiny2313A/4313 23. Typical Characteristics The data contained in this section is largely based on simulations and characterization of similar devices in the same process and design methods. Thus, the data should be treated as indications of how the part will behave. The following charts show typical behavior. These figures are not tested during manufacturing. During characterisation devices are operated at frequencies higher than test limits but they are not guaranteed to function properly at frequencies higher than the ordering code indicates. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. Current consumption is a function of several factors such as operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. A sine wave generator with rail-to-rail output is used as clock source but current consumption in Power-Down mode is independent of clock selection. The difference between current consumption in Power-Down mode with Watchdog Timer enabled and Power-Down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. The current drawn from pins with a capacitive load may be estimated (for one pin) as follows: where VCC = operating voltage, CL = load capacitance and fSW = average switching frequency of I/O pin. 23.1 Effect of Power Reduction Peripheral modules are enabled and disabled via control bits in the Power Reduction Register. See “Power Reduction Register” on page 35 for details. I CP VCC CL × × f SW ≈ Table 23-1. Additional Current Consumption (Absolute) for Peripherals of ATtiny2313A/4313 PRR bit Typical numbers VCC = 2V, f = 1MHz VCC = 3V, f = 4MHz VCC = 5V, f = 8MHz PRTIM0 2 µA 11 µA 50 µA PRTIM1 5 µA 30 µA 120 µA PRUSI 2 µA 11 µA 50 µA PRUSART 4 µA 22 µA 95 µA207 8246B–AVR–09/11 ATtiny2313A/4313 23.2 ATtiny2313A 23.2.1 Current Consumption in Active Mode Figure 23-1. Active Supply Current vs. Low Frequency (0.1 - 1.0 MHz) Figure 23-2. Active Supply Current vs. Frequency (1 - 20 MHz) ACTIVE SUPPLY CURRENT vs. LOW FREQUENCY (ATtiny2313A) (PRR=0xFF) 5.5 V 5.0 V 4.5 V 3.3 V 2.7 V 1.8 V 0 0,2 0,4 0,6 0,8 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) ACTIVE SUPPLY CURRENT vs. FREQUENCY (ATtiny2313A) (PRR=0xFF) 0 2 4 6 8 10 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 1.8V 2.7V 3.3V 4.5V 5.0V 5.5V208 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-3. Active Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) Figure 23-4. Active Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) ACTIVE SUPPLY CURRENT vs. VCC (ATtiny2313A) INTERNAL RC OSCILLATOR, 8 MHz 85 °C 25 °C -40 °C 0 1 2 3 4 5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) ACTIVE SUPPLY CURRENT vs. VCC (ATtiny2313A) INTERNAL RC OSCILLATOR, 1 MHz 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)209 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-5. Active Supply Current vs. VCC (Internal RC Oscillator, 128 KHz) 23.2.2 Current Consumption in Idle Mode Figure 23-6. Idle Supply Current vs. Low Frequency (0.1 - 1.0 MHz) ACTIVE SUPPLY CURRENT vs. VCC (ATtiny2313A) INTERNAL RC OSCILLATOR, 128 KHz 85 °C 25 °C -40 °C 0 0,02 0,04 0,06 0,08 0,1 0,12 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) IDLE SUPPLY CURRENT vs. LOW FREQUENCY (ATtiny2313A) (PRR=0xFF) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0,16 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA)210 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-7. Idle Supply Current vs. Frequency (1 - 20 MHz) Figure 23-8. Idle Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) IDLE SUPPLY CURRENT vs. FREQUENCY (ATtiny2313A) (PRR=0xFF) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,5 1 1,5 2 2,5 3 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) IDLE SUPPLY CURRENT vs. VCC (ATtiny2313A) INTERNAL RC OSCILLATOR, 8 MHz 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)211 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-9. Idle Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) Figure 23-10. Idle Supply Current vs. VCC (Internal RC Oscillator, 128 KHz) IDLE SUPPLY CURRENT vs. VCC (ATtiny2313A) INTERNAL RC OSCILLATOR, 1 MHz 85 °C 25 °C -40 °C 0 0,05 0,1 0,15 0,2 0,25 0,3 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) IDLE SUPPLY CURRENT vs. VCC (ATtiny2313A) INTERNAL RC OSCILLATOR, 128 KHz 85 °C 25 °C -40 °C 0 0,005 0,01 0,015 0,02 0,025 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)212 8246B–AVR–09/11 ATtiny2313A/4313 23.2.3 Current Consumption in Power-down Mode Figure 23-11. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) Figure 23-12. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) POWER-DOWN SUPPLY CURRENT vs. VCC (ATtiny2313A) WATCHDOG TIMER DISABLED 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) POWER-DOWN SUPPLY CURRENT vs. VCC (ATtiny2313A) WATCHDOG TIMER ENABLED 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 7 8 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)213 8246B–AVR–09/11 ATtiny2313A/4313 23.2.4 Current Consumption in Reset Figure 23-13. Reset Supply Current vs. VCC (0.1 - 1.0 MHz, Excluding Current Through The Reset Pull-up) Figure 23-14. Reset Supply Current vs. VCC (1 - 20 MHz, Excluding Current Through The Reset Pull-up) RESET SUPPLY CURRENT vs. VCC (ATtiny2313A) EXCLUDING CURRENT THROUGH THE RESET PULLUP 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V RESET SUPPLY CURRENT vs. VCC (ATtiny2313A) EXCLUDING CURRENT THROUGH THE RESET PULLUP 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 2,2 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA)214 8246B–AVR–09/11 ATtiny2313A/4313 23.2.5 Current Consumption of Peripheral Units Figure 23-15. Brownout Detector Current vs. VCC Figure 23-16. Programming Current vs. VCC (ATtiny2313A) Note: Above programming current based on simulation and characterisation of similar device (ATtiny24A). BROWNOUT DETECTOR CURRENT vs. VCC (ATtiny2313A) BOD level = 1.8V 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) PROGRAMMING CURRENT vs. VCC 85 °C 25 °C -40 °C 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)215 8246B–AVR–09/11 ATtiny2313A/4313 23.2.6 Pull-up Resistors Figure 23-17. Pull-up Resistor Current vs. Input Voltage (I/O Pin, VCC = 1.8V) Figure 23-18. Pull-up Resistor Current vs. Input Voltage (I/O Pin, VCC = 2.7V) I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE (ATtiny2313A) 0 10 20 30 40 50 60 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VOP (V) IOP (uA) 85 °C 25 °C -40 °C 85 °C 25 °C -40 °C I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE (ATtiny2313A) 0 10 20 30 40 50 60 70 80 90 0 0,5 1 1,5 2 2,5 3 VOP (V) IOP (uA)216 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-19. Pull-up Resistor Current vs. Input Voltage (I/O Pin, VCC = 5V) Figure 23-20. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 1.8V) 85 °C 25 °C -40 °C I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE (ATtiny2313A) 0 20 40 60 80 100 120 140 160 0 1 2 3 4 5 6 VOP (V) IOP (uA) RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE (ATtiny2313A) -40 °C 25 °C 85 °C 0 5 10 15 20 25 30 35 40 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VRESET (V) IRESET (uA)217 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-21. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) Figure 23-22. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) -40 °C 25 °C 85 °C RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE (ATtiny2313A) 0 10 20 30 40 50 60 0 0,5 1 1,5 2 2,5 3 VRESET (V) IRESET (uA) -40 °C 25 °C 85 °C RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE (ATtiny2313A) 0 20 40 60 80 100 120 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 VRESET (V) IRESET (uA)218 8246B–AVR–09/11 ATtiny2313A/4313 23.2.7 Output Driver Strength Figure 23-23. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 1.8V) Figure 23-24. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 3V) I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny2313A) Vcc = 1.8V 85 °C 25 °C -40 °C 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 IOL (mA) VOL (V) I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny2313A) Vcc = 3V 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0 2 4 6 8 10 IOL (mA) VOL (V)219 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-25. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 5V) Figure 23-26. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 1.8V) I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny2313A) Vcc = 5V 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0 2 4 6 8 10 12 14 16 18 20 IOL (mA) VOL (V) I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny2313A) Vcc = 1.8V 85 °C 25 °C -40 °C 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 IOH (mA) VOH (V)220 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-27. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 3V) Figure 23-28. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 5V) I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny2313A) Vcc = 3V 85 °C 25 °C -40 °C 2,5 2,6 2,7 2,8 2,9 3 3,1 0 2 4 6 8 10 IOH (mA) VOH (V) I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny2313A) Vcc = 5V 85 °C 25 °C -40 °C 4,3 4,5 4,7 4,9 5,1 0 5 10 15 20 IOH (mA) VOH (V)221 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-29. VOL: Output Voltage vs. Sink Current (Reset Pin as I/O, T = 25°C) Figure 23-30. VOH: Output Voltage vs. Source Current (Reset Pin as I/O, T = 25°C) RESET AS I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny2313A) 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 1 2 3 4 IOL (mA) VOL (V) 5.0 V 1.8 V 3.0 V RESET AS I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny2313A) 5.0 V 3.0 V 1.8 V 0 1 2 3 4 5 0 0,2 0,4 0,6 0,8 1 IOH (mA) VOH (V)222 8246B–AVR–09/11 ATtiny2313A/4313 23.2.8 Input Thresholds and Hysteresis (for I/O Ports) Figure 23-31. VIH: Input Threshold Voltage vs. VCC (I/O Pin Read as ‘1’) Figure 23-32. VIL: Input Threshold Voltage vs. VCC (I/O Pin, Read as ‘0’) I/O PIN INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny2313A) VIH, IO PIN READ AS '1' 0 0,5 1 1,5 2 2,5 3 3,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C I/O PIN INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny2313A) VIL, IO PIN READ AS '0' 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C223 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-33. VIH-VIL: Input Hysteresis vs. VCC (I/O Pin) Figure 23-34. VIH: Input Threshold Voltage vs. VCC (Reset Pin as I/O, Read as ‘1’) I/O PIN INPUT HYSTERESIS vs. VCC (ATtiny2313A) 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) RESET PIN AS I/O THRESHOLD VOLTAGE vs. VCC (ATtiny2313A) VIH, RESET READ AS '1' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)224 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-35. VIL: Input Threshold Voltage vs. VCC (Reset Pin as I/O, Read as ‘0’) Figure 23-36. VIH-VIL: Input Hysteresis vs. VCC (Reset Pin as I/O) RESET PIN AS I/O THRESHOLD VOLTAGE vs. VCC (ATtiny2313A) VIL, RESET READ AS '0' 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C RESET PIN AS IO, INPUT HYSTERESIS vs. VCC (ATtiny2313A) VIL, IO PIN READ AS "0" 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V)225 8246B–AVR–09/11 ATtiny2313A/4313 23.2.9 BOD, Bandgap and Reset Figure 23-37. BOD Thresholds vs. Temperature (BOD Level is 4.3V) Figure 23-38. BOD Thresholds vs. Temperature (BOD Level is 2.7V) BOD THRESHOLDS vs. TEMPERATURE (BOD Level set to 4.3V) (ATtiny2313A) BODLEVEL = 4.3V 4,22 4,24 4,26 4,28 4,3 4,32 4,34 4,36 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (C) Threshold (V) VCC RISING VCC FALLING BOD THRESHOLDS vs. TEMPERATURE (BOD Level set to 2.7V) (ATtiny2313A) BODLEVEL = 2.7V 2,66 2,68 2,7 2,72 2,74 2,76 2,78 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) VCC RISING VCC FALLING226 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-39. BOD Thresholds vs. Temperature (BOD Level is 1.8V) Figure 23-40. Bandgap Voltage vs. Supply Voltage BOD THRESHOLDS vs. TEMPERATURE (BOD Level set to 1.8V) (ATtiny2313A) BODLEVEL = 1.8V 1,78 1,79 1,8 1,81 1,82 1,83 1,84 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) VCC RISING VCC FALLING BANDGAP VOLTAGE vs. VCC (ATtiny2313A) CALIBRATED 0,95 1 1,05 1,1 1,15 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 Vcc (V) Bandgap Voltage (V)227 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-41. Bandgap Voltage vs. Temperature Figure 23-42. VIH: Input Threshold Voltage vs. VCC (Reset Pin, Read as ‘1’) BANDGAP VOLTAGE vs. TEMP (ATtiny2313A) (Vcc=5V) CALIBRATED 1 1,02 1,04 1,06 1,08 1,1 1,12 1,14 1,16 -40 -20 0 20 40 60 80 100 Temperature Bandgap Voltage (V) RESET INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny2313A) VIH, IO PIN READ AS '1' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)228 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-43. VIL: Input Threshold Voltage vs. VCC (Reset Pin, Read as ‘0’) Figure 23-44. VIH-VIL: Input Hysteresis vs. VCC (Reset Pin) RESET INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny2313A) VIL, IO PIN READ AS '0' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) RESET PIN INPUT HYSTERESIS vs. VCC (ATtiny2313A) 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) 85 °C 25 °C -40 °C229 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-45. Minimum Reset Pulse Width vs. VCC 23.2.10 Internal Oscillator Speed Figure 23-46. Calibrated 8 MHz RC Oscillator Frequency vs. VCC MINIMUM RESET PULSE WIDTH vs. VCC (ATtiny2313A) 85 °C 25 °C -40 °C 0 200 400 600 800 1000 1200 1400 1600 1800 2000 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Pulsewidth (ns) CALIBRATED 8.0MHz RC OSCILLATOR FREQUENCY vs. OPERATING VOLTAGE (ATtiny2313A) 7 7,2 7,4 7,6 7,8 8 8,2 8,4 8,6 8,8 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) FRC (MHz) 85 °C 25 °C -40 °C230 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-47. Calibrated 8 MHz RC Oscillator Frequency vs. Temperature Figure 23-48. Calibrated 8 MHz RC Oscillator Frequency vs. Osccal Value CALIBRATED 8.0MHz RC OSCILLATOR FREQUENCY vs. TEMPERATURE (ATtiny2313A) 5.0 V 3.0 V 1.8 V 7 7,5 8 8,5 9 -40 -20 0 20 40 60 80 100 Temperature FRC (MHz) CALIBRATED 8.0MHz RC OSCILLATOR FREQUENCY vs. OSCCAL VALUE (ATtiny2313A) (Vcc=3V) 85 °C 25 °C -40 °C 0 2 4 6 8 10 12 14 0 16 32 48 64 80 96 112 OSCCAL (X1) FRC (MHz)231 8246B–AVR–09/11 ATtiny2313A/4313 23.3 ATtiny4313 23.3.1 Current Consumption in Active Mode Figure 23-49. Active Supply Current vs. Low Frequency (0.1 - 1.0 MHz) Figure 23-50. Active Supply Current vs. Frequency (1 - 20 MHz) ACTIVE SUPPLY CURRENT vs. LOW FREQUENCY (ATtiny4313) (PRR=0xFF) 5.5 V 5.0 V 4.5 V 3.3 V 2.7 V 1.8 V 0 0,2 0,4 0,6 0,8 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) ACTIVE SUPPLY CURRENT vs. FREQUENCY (ATtiny4313) (PRR=0xFF) 0 2 4 6 8 10 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 1.8V 2.7V 3.3V 4.5V 5.0V 5.5V232 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-51. Active Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) Figure 23-52. Active Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) ACTIVE SUPPLY CURRENT vs. VCC (ATtiny4313) INTERNAL RC OSCILLATOR, 8 MHz 85 °C 25 °C -40 °C 0 1 2 3 4 5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) ACTIVE SUPPLY CURRENT vs. VCC (ATtiny4313) INTERNAL RC OSCILLATOR, 1 MHz 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)233 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-53. Active Supply Current vs. VCC (Internal RC Oscillator, 128 KHz) 23.3.2 Current Consumption in Idle Mode Figure 23-54. Idle Supply Current vs. Low Frequency (0.1 - 1.0 MHz) ACTIVE SUPPLY CURRENT vs. VCC (ATtiny4313) INTERNAL RC OSCILLATOR, 128 KHz 85 °C 25 °C -40 °C 0 0,02 0,04 0,06 0,08 0,1 0,12 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) IDLE SUPPLY CURRENT vs. LOW FREQUENCY (ATtiny4313) (PRR=0xFF) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0,16 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA)234 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-55. Idle Supply Current vs. Frequency (1 - 20 MHz) Figure 23-56. Idle Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) IDLE SUPPLY CURRENT vs. FREQUENCY (ATtiny4313) (PRR=0xFF) 0 0,5 1 1,5 2 2,5 3 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V IDLE SUPPLY CURRENT vs. VCC (ATtiny4313) INTERNAL RC OSCILLATOR, 8 MHz 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)235 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-57. Idle Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) Figure 23-58. Idle Supply Current vs. VCC (Internal RC Oscillator, 128 KHz) IDLE SUPPLY CURRENT vs. VCC (ATtiny4313) INTERNAL RC OSCILLATOR, 1 MHz 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) IDLE SUPPLY CURRENT vs. VCC (ATtiny4313) INTERNAL RC OSCILLATOR, 128 KHz 85 °C 25 °C -40 °C 0 0,005 0,01 0,015 0,02 0,025 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)236 8246B–AVR–09/11 ATtiny2313A/4313 23.3.3 Current Consumption in Power-down Mode Figure 23-59. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) Figure 23-60. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) POWER-DOWN SUPPLY CURRENT vs. VCC (ATtiny4313) WATCHDOG TIMER DISABLED 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) POWER-DOWN SUPPLY CURRENT vs. VCC (ATtiny4313) WATCHDOG TIMER ENABLED 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 7 8 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)237 8246B–AVR–09/11 ATtiny2313A/4313 23.3.4 Current Consumption in Reset Figure 23-61. Reset Supply Current vs. VCC (0.1 - 1.0 MHz, Excluding Current Through The Reset Pull-up) Figure 23-62. Reset Supply Current vs. VCC (1 - 20 MHz, Excluding Current Through The Reset Pull-up) RESET SUPPLY CURRENT vs. VCC (ATtiny4313) EXCLUDING CURRENT THROUGH THE RESET PULLUP 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) RESET SUPPLY CURRENT vs. VCC (ATtiny4313) EXCLUDING CURRENT THROUGH THE RESET PULLUP 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 2,2 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V238 8246B–AVR–09/11 ATtiny2313A/4313 23.3.5 Current Consumption of Peripheral Units Figure 23-63. Brownout Detector Current vs. VCC Figure 23-64. Programming Current vs. VCC (ATtiny4313) Note: Above programming current based on simulation and characterisation of similar device (ATtiny44A). BROWNOUT DETECTOR CURRENT vs. VCC (ATtiny4313) BOD level = 1.8V 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) PROGRAMMING CURRENT vs. VCC 85 °C 25 °C -40 °C 0 2000 4000 6000 8000 10000 12000 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)239 8246B–AVR–09/11 ATtiny2313A/4313 23.3.6 Pull-up Resistors Figure 23-65. Pull-up Resistor Current vs. Input Voltage (I/O Pin, VCC = 1.8V) Figure 23-66. Pull-up Resistor Current vs. Input Voltage (I/O Pin, VCC = 2.7V) I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE (ATtiny4313) 0 10 20 30 40 50 60 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VOP (V) IOP (uA) 85 °C 25 °C -40 °C I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE (ATtiny4313) 0 10 20 30 40 50 60 70 80 0 0,5 1 1,5 2 2,5 3 VOP (V) IOP (uA) 85 °C 25 °C -40 °C240 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-67. Pull-up Resistor Current vs. Input Voltage (I/O Pin, VCC = 5V) Figure 23-68. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 1.8V) I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE (ATtiny4313) 0 20 40 60 80 100 120 140 160 0 1 2 3 4 5 6 VOP (V) IOP (uA) 85 °C 25 °C -40 °C RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE (ATtiny4313) 0 5 10 15 20 25 30 35 40 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C241 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-69. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) Figure 23-70. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE (ATtiny4313) 0 10 20 30 40 50 60 0 0,5 1 1,5 2 2,5 3 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE (ATtiny4313) 0 20 40 60 80 100 120 0 1 2 3 4 5 6 VRESET (V) IRESET (uA)242 8246B–AVR–09/11 ATtiny2313A/4313 23.3.7 Output Driver Strength Figure 23-71. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 1.8V) Figure 23-72. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 3V) I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny4313) 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 IOL (mA) VOL (V) VCC = 1.8V 85 °C 25 °C -40 °C I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny4313) 0 0,1 0,2 0,3 0,4 0,5 0,6 0 2 4 6 8 10 IOL (mA) VOL (V) VCC = 3V 85 °C 25 °C -40 °C243 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-73. VOL: Output Voltage vs. Sink Current (I/O Pin, VCC = 5V) Figure 23-74. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 1.8V) I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny4313) 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0 2 4 6 8 10 12 14 16 18 20 IOL (mA) VOL (V) VCC = 5V I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny4313) 1 1,2 1,4 1,6 1,8 2 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 IOH (mA) VOH (V) VCC = 1.8V 85 °C 25 °C -40 °C244 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-75. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 3V) Figure 23-76. VOH: Output Voltage vs. Source Current (I/O Pin, VCC = 5V) I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny4313) 2,5 2,6 2,7 2,8 2,9 3 3,1 0 2 4 6 8 10 IOH (mA) VOH (V) VCC = 3V 85 °C 25 °C -40 °C I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny4313) 85 °C 25 °C -40 °C 4,3 4,5 4,7 4,9 5,1 0 5 10 15 20 IOH (mA) VOH (V) VCC = 5V245 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-77. VOL: Output Voltage vs. Sink Current (Reset Pin as I/O, T = 25°C) Figure 23-78. VOH: Output Voltage vs. Source Current (Reset Pin as I/O, T = 25°C) RESET AS I/O PIN OUTPUT VOLTAGE vs. SINK CURRENT (ATtiny4313) 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 1 2 3 4 IOL (mA) VOL (V) 5.0 V 1.8 V 3.0 V RESET AS I/O PIN OUTPUT VOLTAGE vs. SOURCE CURRENT (ATtiny4313) 0 1 2 3 4 5 0 0,2 0,4 0,6 0,8 1 IOH (mA) VOH (V) 5.0V 3.0V 1.8V246 8246B–AVR–09/11 ATtiny2313A/4313 23.3.8 Input Thresholds and Hysteresis (for I/O Ports) Figure 23-79. VIH: Input Threshold Voltage vs. VCC (I/O Pin Read as ‘1’) Figure 23-80. VIL: Input Threshold Voltage vs. VCC (I/O Pin, Read as ‘0’) I/O PIN INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny4313) VIH, IO PIN READ AS '1' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 3,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) I/O PIN INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny4313) VIL, IO PIN READ AS '0' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)247 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-81. VIH-VIL: Input Hysteresis vs. VCC (I/O Pin) Figure 23-82. VIH: Input Threshold Voltage vs. VCC (Reset Pin as I/O, Read as ‘1’) I/O PIN INPUT HYSTERESIS vs. VCC (ATtiny4313) 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) RESET PIN AS I/O THRESHOLD VOLTAGE vs. VCC (ATtiny4313) VIH, RESET READ AS '1' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)248 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-83. VIL: Input Threshold Voltage vs. VCC (Reset Pin as I/O, Read as ‘0’) Figure 23-84. VIH-VIL: Input Hysteresis vs. VCC (Reset Pin as I/O) RESET PIN AS I/O THRESHOLD VOLTAGE vs. VCC (ATtiny4313) VIL, RESET READ AS '0' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) RESET PIN AS IO, INPUT HYSTERESIS vs. VCC (ATtiny4313) VIL, IO PIN READ AS "0" 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V)249 8246B–AVR–09/11 ATtiny2313A/4313 23.3.9 BOD, Bandgap and Reset Figure 23-85. BOD Thresholds vs. Temperature (BOD Level is 4.3V) Figure 23-86. BOD Thresholds vs. Temperature (BOD Level is 2.7V) BOD THRESHOLDS vs. TEMPERATURE (BOD Level set to 4.3V) (ATtiny4313) BOD Level = 4.3V 4,16 4,18 4,2 4,22 4,24 4,26 4,28 4,3 4,32 4,34 4,36 4,38 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (C) Threshold (V) VCC RISING VCC FALLING BOD THRESHOLDS vs. TEMPERATURE (BOD Level set to 2.7V) (ATtiny4313) BOD Level = 2.7V 2,62 2,64 2,66 2,68 2,7 2,72 2,74 2,76 2,78 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) VCC RISING VCC FALLING250 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-87. BOD Thresholds vs. Temperature (BOD Level is 1.8V) Figure 23-88. Bandgap Voltage vs. Supply Voltage 1,76 1,77 1,78 1,79 1,8 1,81 1,82 1,83 1,84 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) BOD THRESHOLDS vs. TEMPERATURE (BOD Level set to 1.8V) (ATtiny4313) BOD Level = 1.8V VCC RISING VCC FALLING BANDGAP VOLTAGE vs. VCC (ATtiny4313) CALIBRATED 0,95 1 1,05 1,1 1,15 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Bandgap Voltage (V)251 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-89. Bandgap Voltage vs. Temperature Figure 23-90. VIH: Input Threshold Voltage vs. VCC (Reset Pin, Read as ‘1’) BANDGAP VOLTAGE vs. TEMP (ATtiny4313) (Vcc=5V) CALIBRATED 1 1,02 1,04 1,06 1,08 1,1 1,12 1,14 -40 -20 0 20 40 60 80 100 Temperature Bandgap Voltage (V) RESET INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny4313) VIH, IO PIN READ AS '1' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)252 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-91. VIL: Input Threshold Voltage vs. VCC (Reset Pin, Read as ‘0’) Figure 23-92. VIH-VIL: Input Hysteresis vs. VCC (Reset Pin) RESET INPUT THRESHOLD VOLTAGE vs. VCC (ATtiny4313) VIL, IO PIN READ AS '0' 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) RESET PIN INPUT HYSTERESIS vs. VCC (ATtiny4313) 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V)253 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-93. Minimum Reset Pulse Width vs. VCC 23.3.10 Internal Oscillator Speed Figure 23-94. Calibrated 8 MHz RC Oscillator Frequency vs. VCC MINIMUM RESET PULSE WIDTH vs. VCC (ATtiny4313) 85 °C 25 °C -40 °C 0 200 400 600 800 1000 1200 1400 1600 1800 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Pulsewidth (ns) CALIBRATED 8.0MHz RC OSCILLATOR FREQUENCY vs. OPERATING VOLTAGE (ATtiny4313) 7,2 7,4 7,6 7,8 8 8,2 8,4 8,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) FRC (MHz) 85 °C 25 °C -40 °C254 8246B–AVR–09/11 ATtiny2313A/4313 Figure 23-95. Calibrated 8 MHz RC Oscillator Frequency vs. Temperature Figure 23-96. Calibrated 8 MHz RC Oscillator Frequency vs. Osccal Value CALIBRATED 8.0MHz RC OSCILLATOR FREQUENCY vs. TEMPERATURE (ATtiny4313) 5.0 V 3.0 V 1.8 V 7,4 7,6 7,8 8 8,2 8,4 8,6 -40 -20 0 20 40 60 80 100 Temperature FRC (MHz) CALIBRATED 8.0MHz RC OSCILLATOR FREQUENCY vs. OSCCAL VALUE (ATtiny4313) (Vcc=3V) 85 °C 25 °C -40 °C 0 2 4 6 8 10 12 14 0 16 32 48 64 80 96 112 OSCCAL (X1) FRC (MHz)255 8246B–AVR–09/11 ATtiny2313A/4313 24. Register Summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page 0x3F (0x5F) SREG I T H S V N Z C 9 0x3E (0x5E) Reserved – – – – – – – – 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 12 0x3C (0x5C) OCR0B Timer/Counter0 – Compare Register B 86 0x3B (0x5B) GIMSK INT1 INT0 PCIE0 PCIE2 PCIE1 – – – 52 0x3A (0x5A) GIFR INTF1 INTF0 PCIF0 PCIF2 PCIF1 – – – 53 0x39 (0x59) TIMSK TOIE1 OCIE1A OCIE1B – ICIE1 OCIE0B TOIE0 OCIE0A 87, 116 0x38 (0x58) TIFR TOV1 OCF1A OCF1B – ICF1 OCF0B TOV0 OCF0A 87, 117 0x37 (0x57) SPMCSR – – RSIG CTPB RFLB PGWRT PGERS SPMEN 176 0x36 (0x56) OCR0A Timer/Counter0 – Compare Register A 86 0x35 (0x55) MCUCR PUD SM1 SE SM0 ISC11 ISC10 ISC01 ISC00 37, 51, 69 0x34 (0x54) MCUSR – – – – WDRF BORF EXTRF PORF 45 0x33 (0x53) TCCR0B FOC0A FOC0B – – WGM02 CS02 CS01 CS00 85 0x32 (0x52) TCNT0 Timer/Counter0 (8-bit) 86 0x31 (0x51) OSCCAL – CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0 32 0x30 (0x50) TCCR0A COM0A1 COM0A0 COM0B1 COM0B0 – – WGM01 WGM00 82 0x2F (0x4F) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 – – WGM11 WGM10 111 0x2E (0x4E) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 113 0x2D (0x4D) TCNT1H Timer/Counter1 – Counter Register High Byte 115 0x2C (0x4C) TCNT1L Timer/Counter1 – Counter Register Low Byte 115 0x2B (0x4B) OCR1AH Timer/Counter1 – Compare Register A High Byte 115 0x2A (0x4A) OCR1AL Timer/Counter1 – Compare Register A Low Byte 115 0x29 (0x49) OCR1BH Timer/Counter1 – Compare Register B High Byte 115 0x28 (0x48) OCR1BL Timer/Counter1 – Compare Register B Low Byte 115 0x27 (0x47) Reserved – – – – – – – – 0x26 (0x46) CLKPR CLKPCE – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 32 0x25 (0x45) ICR1H Timer/Counter1 - Input Capture Register High Byte 116 0x24 (0x44) ICR1L Timer/Counter1 - Input Capture Register Low Byte 116 0x23 (0x43) GTCCR – – – – – – – PSR10 119 0x22 (ox42) TCCR1C FOC1A FOC1B – – – – – – 114 0x21 (0x41) WDTCSR WDIF WDIE WDP3 WDCE WDE WDP2 WDP1 WDP0 45 0x20 (0x40) PCMSK0 PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 54 0x1F (0x3F) Reserved – – – – – – – – 0x1E (0x3E) EEAR – EEPROM Address Register 24 0x1D (0x3D) EEDR EEPROM Data Register 23 0x1C (0x3C) EECR – – EEPM1 EEPM0 EERIE EEMPE EEPE EERE 24 0x1B (0x3B) PORTA – – – – – PORTA2 PORTA1 PORTA0 69 0x1A (0x3A) DDRA – – – – – DDA2 DDA1 DDA0 69 0x19 (0x39) PINA – – – – – PINA2 PINA1 PINA0 70 0x18 (0x38) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 70 0x17 (0x37) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 70 0x16 (0x36) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 70 0x15 (0x35) GPIOR2 General Purpose I/O Register 2 25 0x14 (0x34) GPIOR1 General Purpose I/O Register 1 25 0x13 (0x33) GPIOR0 General Purpose I/O Register 0 25 0x12 (0x32) PORTD – PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 70 0x11 (0x31) DDRD – DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 70 0x10 (0x30) PIND – PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 70 0x0F (0x2F) USIDR USI Data Register 166 0x0E (0x2E) USISR USISIF USIOIF USIPF USIDC USICNT3 USICNT2 USICNT1 USICNT0 165 0x0D (0x2D) USICR USISIE USIOIE USIWM1 USIWM0 USICS1 USICS0 USICLK USITC 163 0x0C (0x2C) UDR UART Data Register (8-bit) 137 0x0B (0x2B) UCSRA RXC TXC UDRE FE DOR UPE U2X MPCM 138 0x0A (0x2A) UCSRB RXCIE TXCIE UDRIE RXEN TXEN UCSZ2 RXB8 TXB8 139 0x09 (0x29) UBRRL UBRRH[7:0] 141 0x08 (0x28) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 168 0x07 (0x27) BODCR – – – – – – BODS BODSE 38 0x06 (0x26) PRR – – – – PRTIM1 PRTIM0 PRUSI PRUSART 37 0x05 (0x25) PCMSK2 – PCINT17 PCINT16 PCINT15 PCINT14 PCINT13 PCINT12 PCINT11 53 0x04 (0x24) PCMSK1 – – – – – PCINT10 PCINT9 PCINT8 54 0x03 (0x23) UCSRC UMSEL1 UMSEL0 UPM1 UPM0 USBS UCSZ1 UCSZ0 UCPOL 140 0x02 (0x22) UBRRH – – – – UBRRH[11:8] 141 0x01 (0x21) DIDR – – – – – – AIN1D AIN0D 169 0x00 (0x20) USIBR USI Buffer Register 167256 8246B–AVR–09/11 ATtiny2313A/4313 Notes: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the status flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operate on the specified bit, and can therefore be used on registers containing such status flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only. 4. When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing I/O Registers as data space using LD and ST instructions, 0x20 must be added to these addresses. 257 8246B–AVR–09/11 ATtiny2313A/4313 25. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd ← Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd ← Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl ← Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd ← Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd ← Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd ← Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd ← Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl ← Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd ← Rd • Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd ← Rd • K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd ← Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd ← Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd ← Rd ⊕ Rr Z,N,V 1 COM Rd One’s Complement Rd ← 0xFF − Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd ← 0x00 − Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd ← Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd ← Rd • (0xFF - K) Z,N,V 1 INC Rd Increment Rd ← Rd + 1 Z,N,V 1 DEC Rd Decrement Rd ← Rd − 1 Z,N,V 1 TST Rd Test for Zero or Minus Rd ← Rd • Rd Z,N,V 1 CLR Rd Clear Register Rd ← Rd ⊕ Rd Z,N,V 1 SER Rd Set Register Rd ← 0xFF None 1 BRANCH INSTRUCTIONS RJMP k Relative Jump PC ← PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC ← Z None 2 RCALL k Relative Subroutine Call PC ← PC + k + 1 None 3 ICALL Indirect Call to (Z) PC ← Z None 3 RET Subroutine Return PC ← STACK None 4 RETI Interrupt Return PC ← STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC ← PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd − Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd − Rr − C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd − K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC ← PC + 2 or 3 None 1/2/3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC ← PC + 2 or 3 None 1/2/3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PC←PC+k + 1 None 1/2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PC←PC+k + 1 None 1/2 BREQ k Branch if Equal if (Z = 1) then PC ← PC + k + 1 None 1/2 BRNE k Branch if Not Equal if (Z = 0) then PC ← PC + k + 1 None 1/2 BRCS k Branch if Carry Set if (C = 1) then PC ← PC + k + 1 None 1/2 BRCC k Branch if Carry Cleared if (C = 0) then PC ← PC + k + 1 None 1/2 BRSH k Branch if Same or Higher if (C = 0) then PC ← PC + k + 1 None 1/2 BRLO k Branch if Lower if (C = 1) then PC ← PC + k + 1 None 1/2 BRMI k Branch if Minus if (N = 1) then PC ← PC + k + 1 None 1/2 BRPL k Branch if Plus if (N = 0) then PC ← PC + k + 1 None 1/2 BRGE k Branch if Greater or Equal, Signed if (N ⊕ V= 0) then PC ← PC + k + 1 None 1/2 BRLT k Branch if Less Than Zero, Signed if (N ⊕ V= 1) then PC ← PC + k + 1 None 1/2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC ← PC + k + 1 None 1/2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC ← PC + k + 1 None 1/2 BRTS k Branch if T Flag Set if (T = 1) then PC ← PC + k + 1 None 1/2 BRTC k Branch if T Flag Cleared if (T = 0) then PC ← PC + k + 1 None 1/2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC ← PC + k + 1 None 1/2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC ← PC + k + 1 None 1/2 BRIE k Branch if Interrupt Enabled if ( I = 1) then PC ← PC + k + 1 None 1/2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC ← PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b) ← 1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b) ← 0 None 2 LSL Rd Logical Shift Left Rd(n+1) ← Rd(n), Rd(0) ← 0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n) ← Rd(n+1), Rd(7) ← 0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)←C,Rd(n+1)← Rd(n),C←Rd(7) Z,C,N,V 1258 8246B–AVR–09/11 ATtiny2313A/4313 ROR Rd Rotate Right Through Carry Rd(7)←C,Rd(n)← Rd(n+1),C←Rd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n) ← Rd(n+1), n=0..6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3..0)←Rd(7..4),Rd(7..4)←Rd(3..0) None 1 BSET s Flag Set SREG(s) ← 1 SREG(s) 1 BCLR s Flag Clear SREG(s) ← 0 SREG(s) 1 BST Rr, b Bit Store from Register to T T ← Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b) ← T None 1 SEC Set Carry C ← 1 C1 CLC Clear Carry C ← 0 C 1 SEN Set Negative Flag N ← 1 N1 CLN Clear Negative Flag N ← 0 N 1 SEZ Set Zero Flag Z ← 1 Z1 CLZ Clear Zero Flag Z ← 0 Z 1 SEI Global Interrupt Enable I ← 1 I1 CLI Global Interrupt Disable I ← 0 I 1 SES Set Signed Test Flag S ← 1 S1 CLS Clear Signed Test Flag S ← 0 S 1 SEV Set Twos Complement Overflow. V ← 1 V1 CLV Clear Twos Complement Overflow V ← 0 V 1 SET Set T in SREG T ← 1 T1 CLT Clear T in SREG T ← 0 T 1 SEH Set Half Carry Flag in SREG H ← 1 H1 CLH Clear Half Carry Flag in SREG H ← 0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd ← Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd ← Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd ← K None 1 LD Rd, X Load Indirect Rd ← (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd ← (X), X ← X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X ← X - 1, Rd ← (X) None 2 LD Rd, Y Load Indirect Rd ← (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd ← (Y), Y ← Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y ← Y - 1, Rd ← (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd ← (Y + q) None 2 LD Rd, Z Load Indirect Rd ← (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd ← (Z), Z ← Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z ← Z - 1, Rd ← (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd ← (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd ← (k) None 2 ST X, Rr Store Indirect (X) ← Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) ← Rr, X ← X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X ← X - 1, (X) ← Rr None 2 ST Y, Rr Store Indirect (Y) ← Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y) ← Rr, Y ← Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y ← Y - 1, (Y) ← Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q) ← Rr None 2 ST Z, Rr Store Indirect (Z) ← Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z) ← Rr, Z ← Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z ← Z - 1, (Z) ← Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q) ← Rr None 2 STS k, Rr Store Direct to SRAM (k) ← Rr None 2 LPM Load Program Memory R0 ← (Z) None 3 LPM Rd, Z Load Program Memory Rd ← (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd ← (Z), Z ← Z+1 None 3 SPM Store Program Memory (Z) ← R1:R0 None - IN Rd, P In Port Rd ← P None 1 OUT P, Rr Out Port P ← Rr None 1 PUSH Rr Push Register on Stack STACK ← Rr None 2 POP Rd Pop Register from Stack Rd ← STACK None 2 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/timer) None 1 BREAK Break For On-chip Debug Only None N/A Mnemonics Operands Description Operation Flags #Clocks259 8246B–AVR–09/11 ATtiny2313A/4313 26. Ordering Information Notes: 1. For speed vs. supply voltage, see section 22.3 “Speed” on page 200. 2. All packages are Pb-free, halide-free and fully green, and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: – H: NiPdAu lead finish – U or N: matte tin – R: tape & reel 4. Can also be supplied in wafer form. Contact your local Atmel sales office for ordering information and minimum quantities. 5. NiPdAu finish 6. Topside markings : – 1st Line: T2313 – 2nd Line: Axx – 3rd Line: xxx 26.1 ATtiny2313A Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 20 1.8 – 5.5 Industrial (-40°C to +85°C) (4) 20P3 ATtiny2313A-PU 20S ATtiny2313A-SU ATtiny2313A-SUR 20M1 ATtiny2313A-MU ATtiny2313A-MUR 20M2 (5)(6) ATtiny2313A-MMH ATtiny2313A-MMHR Package Type 20P3 20-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 20S 20-lead, 0.300" Wide, Plastic Gull Wing Small Outline Package (SOIC) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No-Lead / Micro Lead Frame Package (MLF) 20M2 20-pad, 3 x 3 x 0.85 mm Body, Very Thin Quad Flat No Lead Package (VQFN)260 8246B–AVR–09/11 ATtiny2313A/4313 Notes: 1. For speed vs. supply voltage, see section 22.3 “Speed” on page 200. 2. All packages are Pb-free, halide-free and fully green, and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: – H: NiPdAu lead finish – U or N: matte tin – R: tape & reel 4. Can also be supplied in wafer form. Contact your local Atmel sales office for ordering information and minimum quantities. 5. NiPdAu finish 6. Topside markings: – 1st Line: T4313 – 2nd Line: Axx – 3rd Line: xxx 26.2 ATtiny4313 Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 20 1.8 – 5.5 Industrial (-40°C to +85°C) (4) 20P3 ATtiny4313-PU 20S ATtiny4313-SU ATtiny4313-SUR 20M1 ATtiny4313-MU ATtiny4313-MUR 20M2 (5)(6) ATtiny4313-MMH ATtiny4313-MMHR Package Type 20P3 20-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 20S 20-lead, 0.300" Wide, Plastic Gull Wing Small Outline Package (SOIC) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No-Lead/Micro Lead Frame Package (MLF) 20M2 20-pad, 3 x 3 x 0.85 mm Body, Very Thin Quad Flat No Lead Package (VQFN)261 8246B–AVR–09/11 ATtiny2313A/4313 27. Packaging Information 27.1 20P3 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 20P3, 20-lead (0.300"/7.62 mm Wide) Plastic Dual Inline Package (PDIP) 20P3 D 2010-10-19 PIN 1 E1 A1 B E B1 C L SEATING PLANE A D e eB eC COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A – – 5.334 A1 0.381 – – D 25.493 – 25.984 Note 2 E 7.620 – 8.255 E1 6.096 – 7.112 Note 2 B 0.356 – 0.559 B1 1.270 – 1.551 L 2.921 – 3.810 C 0.203 – 0.356 eB – – 10.922 eC 0.000 – 1.524 e 2.540 TYP Notes: 1. This package conforms to JEDEC reference MS-001, Variation AD. 2. Dimensions D and E1 do not include mold Flash or Protrusion. Mold Flash or Protrusion shall not exceed 0.25 mm (0.010"). 262 8246B–AVR–09/11 ATtiny2313A/4313 27.2 20S263 8246B–AVR–09/11 ATtiny2313A/4313 27.3 20M1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 20M1, 20-pad, 4 x 4 x 0.8 mm Body, Lead Pitch 0.50 mm, 20M1 A 10/27/04 2.6 mm Exposed Pad, Micro Lead Frame Package (MLF) A 0.70 0.75 0.80 A1 – 0.01 0.05 A2 0.20 REF b 0.18 0.23 0.30 D 4.00 BSC D2 2.45 2.60 2.75 E 4.00 BSC E2 2.45 2.60 2.75 e 0.50 BSC L 0.35 0.40 0.55 SIDE VIEW Pin 1 ID Pin #1 Notch (0.20 R) BOTTOM VIEW TOP VIEW Note: Reference JEDEC Standard MO-220, Fig. 1 (SAW Singulation) WGGD-5. COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE D E e A2 A1 A D2 E2 0.08 C L 1 2 3 b 1 2 3264 8246B–AVR–09/11 ATtiny2313A/4313 27.4 20M2 TITLE GPC DRAWING NO. REV. Package Drawing Contact: packagedrawings@atmel.com ZFC B 20M2 20M2, 20-pad, 3 x 3 x 0.85 mm Body, Lead Pitch 0.45 mm, 1.55 x 1.55 mm Exposed Pad, Thermally Enhanced Plastic Very Thin Quad Flat No Lead Package (VQFN) 10/24/08 15 14 13 12 11 1 2 3 4 5 16 17 18 19 20 10 9 8 7 6 D2 E2 e b L K Pin #1 Chamfer (C 0.3) D E SIDE VIEW A1 y Pin 1 ID BOTTOM VIEW TOP VIEW A C C0.18 (8X) 0.3 Ref (4x) COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A 0.75 0.80 0.85 A1 0.00 0.02 0.05 b 0.17 0.22 0.27 C 0.152 D 2.90 3.00 3.10 D2 1.40 1.55 1.70 E 2.90 3.00 3.10 E2 1.40 1.55 1.70 e – 0.45 – L 0.35 0.40 0.45 K 0.20 – – y 0.00 – 0.08 265 8246B–AVR–09/11 ATtiny2313A/4313 28. Errata The revision letters in this section refer to the revision of the corresponding ATtiny2313A/4313 device. 28.1 ATtiny2313A 28.1.1 Rev. D No known errata. 28.1.2 Rev. A – C These device revisions were referred to as ATtiny2313/ATtiny2313V. 28.2 ATtiny4313 28.2.1 Rev. A No known errata.266 8246B–AVR–09/11 ATtiny2313A/4313 29. Datasheet Revision History 29.1 Rev. 8246B – 10/11 1. Updated device status from Preliminary to Final. 2. Updated document template. 3. Added order codes for tape&reel devices, on page 259 and page 260 4. Updated figures: – Figure 23-33 on page 223 – Figure 23-44 on page 228 – Figure 23-81 on page 247 – Figure 23-92 on page 252 5. Updated sections: – Section 5. “Memories” on page 16 – Section 19. “Self-Programming” on page 173 – Section 20. “Lock Bits, Fuse Bits and Device Signature” on page 178 – Section 21. “External Programming” on page 184 – Section 26. “Ordering Information” on page 259 29.2 Rev. 8246A – 11/09 1. Initial revision. Created from document 2543_t2313. 2. Updated datasheet template. 3. Added VQFN in the Pinout Figure 1-1 on page 2. 4. Added Section 7.2 “Software BOD Disable” on page 35. 5. Added Section 7.3 “Power Reduction Register” on page 35. 6. Updated Table 7-2, “Sleep Mode Select,” on page 37. 7. Added Section 7.5.3 “BODCR – Brown-Out Detector Control Register” on page 38. 8. Added reset disable function in Figure 8-1 on page 39. 9. Added pin change interrupts PCINT1 and PCINT2 in Table 9-1 on page 48. 10. Added PCINT17..8 and PCMSK2..1 in Section 9.2 “External Interrupts” on page 49. 11. Added Section 9.3.4 “PCMSK2 – Pin Change Mask Register 2” on page 53. 12. Added Section 9.3.5 “PCMSK1 – Pin Change Mask Register 1” on page 54. 13. Updated Section 10.2.1 “Alternate Functions of Port A” on page 62. 14. Updated Section 10.2.2 “Alternate Functions of Port B” on page 63. 15. Updated Section 10.2.3 “Alternate Functions of Port D” on page 67. 16. Added UMSEL1 and UMSEL0 in Section 14.10.4 “UCSRC – USART Control and Status Register C” on page 140. 17. Added Section 15. “USART in SPI Mode” on page 146. 18. Added USI Buffer Register (USIBR) in Section 16.2 “Overview” on page 156 and in Figure 16-1 on page 156. 19. Added Section 16.5.4 “USIBR – USI Buffer Register” on page 167. 20. Updated Section 19.6.3 “Reading Device Signature Imprint Table from Firmware” on page 175.267 8246B–AVR–09/11 ATtiny2313A/4313 21. Updated Section 19.7.1 “SPMCSR – Store Program Memory Control and Status Register” on page 176. 22. Added Section 20.3 “Device Signature Imprint Table” on page 180. 23. Updated Section 20.3.1 “Calibration Byte” on page 181. 24. Changed BS to BS1 in Section 20.6.13 “Reading the Signature Bytes” on page 189. 25. Updated Section 22.2 “DC Characteristics” on page 198. 26. Added Section 23.1 “Effect of Power Reduction” on page 206. 27. Updated characteristic plots in Section 23. “Typical Characteristics” for ATtiny2313A (pages 207 - 230), and added plots for ATtiny4313 (pages 231 - 254). 28. Updated Section 24. “Register Summary” on page 255 . 29. Updated Section 26. “Ordering Information” on page 259, added the package type 20M2 and the ordering code -MMH (VQFN), and added the topside marking note.268 8246B–AVR–09/11 ATtiny2313A/4313i 8246B–AVR–09/11 ATtiny2313A/4313 Table of Contents Features ..................................................................................................... 1 1 Pin Configurations ................................................................................... 2 1.1 Pin Descriptions .................................................................................................3 2 Overview ................................................................................................... 5 2.1 Block Diagram ...................................................................................................5 2.2 Comparison Between ATtiny2313A and ATtiny4313 ........................................6 3 About ......................................................................................................... 7 3.1 Resources .........................................................................................................7 3.2 Code Examples .................................................................................................7 3.3 Data Retention ...................................................................................................7 4 CPU Core .................................................................................................. 8 4.1 Architectural Overview .......................................................................................8 4.2 ALU – Arithmetic Logic Unit ...............................................................................9 4.3 Status Register ..................................................................................................9 4.4 General Purpose Register File ........................................................................10 4.5 Stack Pointer ...................................................................................................12 4.6 Instruction Execution Timing ...........................................................................12 4.7 Reset and Interrupt Handling ...........................................................................13 5 Memories ................................................................................................ 15 5.1 Program Memory (Flash) .................................................................................15 5.2 Data Memory (SRAM) and Register Files .......................................................16 5.3 Data Memory (EEPROM) ................................................................................17 5.4 Register Description ........................................................................................22 6 Clock System ......................................................................................... 25 6.1 Clock Subsystems ...........................................................................................25 6.2 Clock Sources .................................................................................................26 6.3 System Clock Prescaler ..................................................................................30 6.4 Clock Output Buffer .........................................................................................31 6.5 Register Description ........................................................................................31 7 Power Management and Sleep Modes ................................................. 33 7.1 Sleep Modes ....................................................................................................33 7.2 Software BOD Disable .....................................................................................34ii 8246B–AVR–09/11 ATtiny2313A/4313 7.3 Power Reduction Register ...............................................................................34 7.4 Minimizing Power Consumption ......................................................................35 7.5 Register Description ........................................................................................36 8 System Control and Reset .................................................................... 38 8.1 Resetting the AVR ...........................................................................................38 8.2 Reset Sources .................................................................................................39 8.3 Internal Voltage Reference ..............................................................................41 8.4 Watchdog Timer ..............................................................................................41 8.5 Register Description ........................................................................................44 9 Interrupts ................................................................................................ 47 9.1 Interrupt Vectors ..............................................................................................47 9.2 External Interrupts ...........................................................................................48 9.3 Register Description ........................................................................................50 10 I/O-Ports .................................................................................................. 54 10.1 Ports as General Digital I/O .............................................................................55 10.2 Alternate Port Functions ..................................................................................59 10.3 Register Description ........................................................................................68 11 8-bit Timer/Counter0 with PWM ............................................................ 70 11.1 Features ..........................................................................................................70 11.2 Overview ..........................................................................................................70 11.3 Clock Sources .................................................................................................71 11.4 Counter Unit ....................................................................................................71 11.5 Output Compare Unit .......................................................................................72 11.6 Compare Match Output Unit ............................................................................74 11.7 Modes of Operation .........................................................................................75 11.8 Timer/Counter Timing Diagrams .....................................................................79 11.9 Register Description ........................................................................................81 12 16-bit Timer/Counter1 ............................................................................ 88 12.1 Features ..........................................................................................................88 12.2 Overview ..........................................................................................................88 12.3 Timer/Counter Clock Sources .........................................................................90 12.4 Counter Unit ....................................................................................................90 12.5 Input Capture Unit ...........................................................................................91 12.6 Output Compare Units .....................................................................................93iii 8246B–AVR–09/11 ATtiny2313A/4313 12.7 Compare Match Output Unit ............................................................................95 12.8 Modes of Operation .........................................................................................96 12.9 Timer/Counter Timing Diagrams ...................................................................104 12.10 Accessing 16-bit Registers ............................................................................106 12.11 Register Description ......................................................................................110 13 Timer/Counter0 and Timer/Counter1 Prescalers .............................. 117 13.1 Internal Clock Source ....................................................................................117 13.2 Prescaler Reset .............................................................................................117 13.3 External Clock Source ...................................................................................117 13.4 Register Description ......................................................................................118 14 USART ................................................................................................... 119 14.1 Features ........................................................................................................119 14.2 Overview ........................................................................................................119 14.3 Clock Generation ...........................................................................................120 14.4 Frame Formats ..............................................................................................123 14.5 USART Initialization .......................................................................................124 14.6 Data Transmission – The USART Transmitter ..............................................125 14.7 Data Reception – The USART Receiver .......................................................129 14.8 Asynchronous Data Reception ......................................................................132 14.9 Multi-processor Communication Mode ..........................................................135 14.10 Register Description ......................................................................................136 14.11 Examples of Baud Rate Setting .....................................................................141 15 USART in SPI Mode ............................................................................. 145 15.1 Features ........................................................................................................145 15.2 Overview ........................................................................................................145 15.3 Clock Generation ...........................................................................................145 15.4 SPI Data Modes and Timing ..........................................................................146 15.5 Frame Formats ..............................................................................................147 15.6 Data Transfer .................................................................................................149 15.7 AVR USART MSPIM vs. AVR SPI ................................................................151 15.8 Register Description ......................................................................................152 16 USI – Universal Serial Interface .......................................................... 155 16.1 Features ........................................................................................................155 16.2 Overview ........................................................................................................155 16.3 Functional Descriptions .................................................................................156iv 8246B–AVR–09/11 ATtiny2313A/4313 16.4 Alternative USI Usage ...................................................................................162 16.5 Register Description ......................................................................................162 17 Analog Comparator ............................................................................. 167 17.1 Register Description ......................................................................................167 18 debugWIRE On-chip Debug System .................................................. 169 18.1 Features ........................................................................................................169 18.2 Overview ........................................................................................................169 18.3 Physical Interface ..........................................................................................169 18.4 Software Break Points ...................................................................................170 18.5 Limitations of debugWIRE .............................................................................170 18.6 Register Description ......................................................................................171 19 Self-Programming ................................................................................ 172 19.1 Features ........................................................................................................172 19.2 Overview ........................................................................................................172 19.3 Lock Bits ........................................................................................................172 19.4 Self-Programming the Flash ..........................................................................172 19.5 Preventing Flash Corruption ..........................................................................175 19.6 Programming Time for Flash when Using SPM ............................................175 19.7 Register Description ......................................................................................175 20 Lock Bits, Fuse Bits and Device Signature ....................................... 177 20.1 Lock Bits ........................................................................................................177 20.2 Fuse Bits ........................................................................................................178 20.3 Device Signature Imprint Table .....................................................................179 20.4 Reading Lock Bits, Fuse Bits and Signature Data from Software .................180 21 External Programming ........................................................................ 183 21.1 Memory Parametrics .....................................................................................183 21.2 Parallel Programming ....................................................................................183 21.3 Serial Programming .......................................................................................192 21.4 Programming Time for Flash and EEPROM .................................................196 22 Electrical Characteristics .................................................................... 198 22.1 Absolute Maximum Ratings* .........................................................................198 22.2 DC Characteristics .........................................................................................198 22.3 Speed ............................................................................................................199 22.4 Clock Characteristics .....................................................................................200v 8246B–AVR–09/11 ATtiny2313A/4313 22.5 System and Reset Characteristics ................................................................201 22.6 Analog Comparator Characteristics ...............................................................202 22.7 Parallel Programming Characteristics ...........................................................203 22.8 Serial Programming Characteristics ..............................................................205 23 Typical Characteristics ........................................................................ 206 23.1 Effect of Power Reduction .............................................................................206 23.2 ATtiny2313A ..................................................................................................207 23.3 ATtiny4313 ....................................................................................................231 24 Register Summary ............................................................................... 255 25 Instruction Set Summary .................................................................... 257 26 Ordering Information ........................................................................... 259 26.1 ATtiny2313A ..................................................................................................259 26.2 ATtiny4313 ....................................................................................................260 27 Packaging Information ........................................................................ 261 27.1 20P3 ..............................................................................................................261 27.2 20S ................................................................................................................262 27.3 20M1 ..............................................................................................................263 27.4 20M2 ..............................................................................................................264 28 Errata ..................................................................................................... 265 28.1 ATtiny2313A ..................................................................................................265 28.2 ATtiny4313 ....................................................................................................265 29 Datasheet Revision History ................................................................ 266 29.1 Rev. 8246B – 10/11 .......................................................................................266 29.2 Rev. 8246A – 11/09 .......................................................................................2668246B–AVR–09/11 Headquarters International Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Atmel Asia Limited Unit 01-5 & 16, 19/F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (852) 2245-6100 Fax: (852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 JAPAN Tel: (81) 3-3523-3551 Fax: (81) 3-3523-7581 Product Contact Web Site www.atmel.com Technical Support avr@atmel.com Sales Contact www.atmel.com/contacts Literature Requests www.atmel.com/literature Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDITIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 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Atmel®, logo and combinations thereof, AVR® and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Features • High Performance, Low Power AVR® 8-bit Microcontroller • Advanced RISC Architecture – 120 Powerful Instructions – Most Single Clock Cycle Execution – 32 x 8 General Purpose Working Registers – Fully Static Operation • High Endurance, Non-volatile Memory Segments – 2K/4K/8K Bytes of In-System, Self-programmable Flash Program Memory • Endurance: 10,000 Write/Erase Cycles – 128/256/512 Bytes of In-System Programmable EEPROM • Endurance: 100,000 Write/Erase Cycles – 128/256/512 Bytes of Internal SRAM – Data Retention: 20 years at 85°C / 100 years at 25°C – Programming Lock for Self-programming Flash & EEPROM Data Security • Peripheral Features – One 8-bit and One 16-bit Timer/Counter with Two PWM Channels, Each – 10-bit ADC • 8 Single-ended Channels • 12 Differential ADC Channel Pairs with Programmable Gain (1x / 20x) – Programmable Watchdog Timer with Separate On-chip Oscillator – On-chip Analog Comparator – Universal Serial Interface • Special Microcontroller Features – debugWIRE On-chip Debug System – In-System Programmable via SPI Port – Internal and External Interrupt Sources • Pin Change Interrupt on 12 Pins – Low Power Idle, ADC Noise Reduction, Standby and Power-down Modes – Enhanced Power-on Reset Circuit – Programmable Brown-out Detection Circuit with Software Disable Function – Internal Calibrated Oscillator – On-chip Temperature Sensor • I/O and Packages – Available in 20-pin QFN/MLF/VQFN, 14-pin SOIC, 14-pin PDIP and 15-ball UFBGA – Twelve Programmable I/O Lines • Operating Voltage: – 1.8 – 5.5V • Speed Grade: – 0 – 4 MHz @ 1.8 – 5.5V – 0 – 10 MHz @ 2.7 – 5.5V – 0 – 20 MHz @ 4.5 – 5.5V • Industrial Temperature Range: -40°C to +85°C • Low Power Consumption – Active Mode: • 210 µA at 1.8V and 1 MHz – Idle Mode: • 33 µA at 1.8V and 1 MHz – Power-down Mode: • 0.1 µA at 1.8V and 25°C 8-bit Microcontroller with 2K/4K/8K Bytes In-System Programmable Flash ATtiny24A ATtiny44A ATtiny84A Rev. 8183F–AVR–06/122 8183F–AVR–06/12 ATtiny24A/44A/84A 1. Pin Configurations Figure 1-1. Pinout of ATtiny24A/44A/84A Table 1-1. UFBGA - Pinout ATtiny24A/44A/84A (top view) 1234 A PA5 PA6 PB2 B PA4 PA7 PB1 PB3 C PA3 PA2 PA1 PB0 D PA0 GND GND VCC 1 2 3 4 5 6 7 14 13 12 11 10 9 8 VCC (PCINT8/XTAL1/CLKI) PB0 (PCINT9/XTAL2) PB1 (PCINT11/RESET/dW) PB3 (PCINT10/INT0/OC0A/CKOUT) PB2 (PCINT7/ICP/OC0B/ADC7) PA7 (PCINT6/OC1A/SDA/MOSI/DI/ADC6) PA6 GND PA0 (ADC0/AREF/PCINT0) PA1 (ADC1/AIN0/PCINT1) PA2 (ADC2/AIN1/PCINT2) PA3 (ADC3/T0/PCINT3) PA4 (ADC4/USCK/SCL/T1/PCINT4) PA5 (ADC5/DO/MISO/OC1B/PCINT5) PDIP/SOIC 1 2 3 4 5 QFN/MLF/VQFN 15 14 13 12 11 20 19 18 17 16 6 7 8 9 10 NOTE Bottom pad should be soldered to ground. DNC: Do Not Connect DNC DNC GND VCC DNC PA7 (PCINT7/ICP/OC0B/ADC7) PB2 (PCINT10/INT0/OC0A/CKOUT) PB3 (PCINT11/RESET/dW) PB1 (PCINT9/XTAL2) PB0 (PCINT8/XTAL1/CLKI) PA5 DNC DNC DNC PA6 Pin 16: PA6 (PCINT6/OC1A/SDA/MOSI/DI/ADC6) Pin 20: PA5 (ADC5/DO/MISO/OC1B/PCINT5) (ADC4/USCK/SCL/T1/PCINT4) PA4 (ADC3/T0/PCINT3) PA3 (ADC2/AIN1/PCINT2) PA2 (ADC1/AIN0/PCINT1) PA1 (ADC0/AREF/PCINT0) PA03 8183F–AVR–06/12 ATtiny24A/44A/84A 1.1 Pin Descriptions 1.1.1 VCC Supply voltage. 1.1.2 GND Ground. 1.1.3 Port B (PB3:PB0) Port B is a 4-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability except PB3 which has the RESET capability. To use pin PB3 as an I/O pin, instead of RESET pin, program (‘0’) RSTDISBL fuse. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port B also serves the functions of various special features of the ATtiny24A/44A/84A as listed in Section 10.2 “Alternate Port Functions” on page 58. 1.1.4 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running and provided the reset pin has not been disabled. The minimum pulse length is given in Table 20-4 on page 176. Shorter pulses are not guaranteed to generate a reset. The reset pin can also be used as a (weak) I/O pin. 1.1.5 Port A (PA7:PA0) Port A is a 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port A output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port A pins that are externally pulled low will source current if the pull-up resistors are activated. The Port A pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port A has alternate functions as analog inputs for the ADC, analog comparator, timer/counter, SPI and pin change interrupt as described in “Alternate Port Functions” on page 58.4 8183F–AVR–06/12 ATtiny24A/44A/84A 2. Overview ATtiny24A/44A/84A are low-power CMOS 8-bit microcontrollers based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny24A/44A/84A achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. Figure 2-1. Block Diagram The AVR core combines a rich instruction set with 32 general purpose working registers. All 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. WATCHDOG TIMER MCU CONTROL REGISTER TIMER/ COUNTER0 DATA DIR. REG.PORT A DATA REGISTER PORT A PROGRAMMING LOGIC TIMING AND CONTROL MCU STATUS REGISTER PORT A DRIVERS PA[7:0] VCC GND + _ ANALOG COMPARATOR 8-BIT DATABUS ADC ISP INTERFACE INTERRUPT UNIT EEPROM INTERNAL OSCILLATOR OSCILLATORS CALIBRATED OSCILLATOR INTERNAL DATA DIR. REG.PORT B DATA REGISTER PORT B PORT B DRIVERS PB[3:0] PROGRAM COUNTER STACK POINTER PROGRAM FLASH SRAM GENERAL PURPOSE REGISTERS INSTRUCTION REGISTER INSTRUCTION DECODER STATUS REGISTER Z Y X ALU CONTROL LINES TIMER/ COUNTER15 8183F–AVR–06/12 ATtiny24A/44A/84A The ATtiny24A/44A/84A provides the following features: 2K/4K/8K byte of In-System Programmable Flash, 128/256/512 bytes EEPROM, 128/256/512 bytes SRAM, 12 general purpose I/O lines, 32 general purpose working registers, an 8-bit Timer/Counter with two PWM channels, a 16-bit timer/counter with two PWM channels, Internal and External Interrupts, a 8-channel 10-bit ADC, programmable gain stage (1x, 20x) for 12 differential ADC channel pairs, a programmable Watchdog Timer with internal oscillator, internal calibrated oscillator, and four software selectable power saving modes. Idle mode stops the CPU while allowing the SRAM, Timer/Counter, ADC, Analog Comparator, and Interrupt system to continue functioning. ADC Noise Reduction mode minimizes switching noise during ADC conversions by stopping the CPU and all I/O modules except the ADC. In Power-down mode registers keep their contents and all chip functions are disbaled until the next interrupt or hardware reset. In Standby mode, the crystal/resonator oscillator is running while the rest of the device is sleeping, allowing very fast start-up combined with low power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The onchip ISP Flash allows the Program memory to be re-programmed in-system through an SPI serial interface, by a conventional non-volatile memory programmer or by an on-chip boot code running on the AVR core. The ATtiny24A/44A/84A AVR is supported with a full suite of program and system development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators and Evaluation kits.6 8183F–AVR–06/12 ATtiny24A/44A/84A 3. General Information 3.1 Resources A comprehensive set of drivers, application notes, data sheets and descriptions on development tools are available for download at http://www.atmel.com/avr. 3.2 Code Examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. For I/O Registers located in the extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with instructions that allow access to extended I/O. Typically, this means “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”. Note that not all AVR devices include an extended I/O map. 3.3 Capacitive Touch Sensing Atmel QTouch Library provides a simple to use solution for touch sensitive interfaces on Atmel AVR microcontrollers. The QTouch Library includes support for QTouch® and QMatrix® acquisition methods. Touch sensing is easily added to any application by linking the QTouch Library and using the Application Programming Interface (API) of the library to define the touch channels and sensors. The application then calls the API to retrieve channel information and determine the state of the touch sensor. The QTouch Library is free and can be downloaded from the Atmel website. For more information and details of implementation, refer to the QTouch Library User Guide – also available from the Atmel website. 3.4 Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C. 3.5 Disclaimer Typical values contained in this datasheet are based on simulations and characterization of other AVR microcontrollers manufactured on the same process technology. Min and Max values will be available after the device has been characterized.7 8183F–AVR–06/12 ATtiny24A/44A/84A 4. CPU Core This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. 4.1 Architectural Overview Figure 4-1. Block Diagram of the AVR Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the Program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the Program memory. This concept enables instructions to be executed in every clock cycle. The Program memory is In-System Reprogrammable Flash memory. Flash Program Memory Instruction Register Instruction Decoder Program Counter Control Lines 32 x 8 General Purpose Registrers ALU Status and Control I/O Lines EEPROM Data Bus 8-bit Data SRAM Direct Addressing Indirect Addressing Interrupt Unit Watchdog Timer Analog Comparator Timer/Counter 0 Timer/Counter 1 Universal Serial Interface ADC8 8183F–AVR–06/12 ATtiny24A/44A/84A The fast-access Register File contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash Program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, capable of directly addressing the whole address space. Most AVR instructions have a single 16-bit word format but 32-bit wide instructions also exist. The actual instruction set varies, as some devices only implement a part of the instruction set. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. 4.2 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See the “Instruction Set” section for a detailed description. 4.3 Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code.9 8183F–AVR–06/12 ATtiny24A/44A/84A The Status Register is neither automatically stored when entering an interrupt routine, nor restored when returning from an interrupt. This must be handled by software. 4.4 General Purpose Register File The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 4-2 below shows the structure of the 32 general purpose working registers in the CPU. Figure 4-2. AVR CPU General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 4-2, each register is also assigned a Data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y- and Z-pointer registers can be set to index any register in the file. 4.4.1 The X-register, Y-register, and Z-register The registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 4-3 below. Figure 4-3. The X-, Y-, and Z-registers 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E Purpose R15 0x0F Working R16 0x10 Registers R17 0x11 … R26 0x1A X-register Low Byte R27 0x1B X-register High Byte R28 0x1C Y-register Low Byte R29 0x1D Y-register High Byte R30 0x1E Z-register Low Byte R31 0x1F Z-register High Byte 15 XH XL 010 8183F–AVR–06/12 ATtiny24A/44A/84A In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the instruction set reference for details). 4.5 Stack Pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x60. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when data is popped from the Stack with return from subroutine RET or return from interrupt RETI. The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. 4.6 Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 4-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. X-register 7 0 7 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 0 7 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 7 0 7 0 R31 (0x1F) R30 (0x1E)11 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 4-4. The Parallel Instruction Fetches and Instruction Executions Figure 4-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 4-5. Single Cycle ALU Operation 4.7 Reset and Interrupt Handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate Program Vector in the Program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. The lowest addresses in the Program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 47. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPU Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPU12 8183F–AVR–06/12 ATtiny24A/44A/84A to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence. Note: See “Code Examples” on page 6. Assembly Code Example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMPE ; start EEPROM write sbi EECR, EEPE out SREG, r16 ; restore SREG value (I-bit) C Code Example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ _CLI(); EECR |= (1< ... ... 9.2 External Interrupts External Interrupts are triggered by the INT0 pin or any of the PCINT[11:0] pins. Observe that, if enabled, the interrupts will trigger even if the INT0 or PCINT[11:0] pins are configured as outputs. This feature provides a way of generating a software interrupt. Pin change 0 interrupts PCI0 will trigger if any enabled PCINT[7:0] pin toggles. Pin change 1 interrupts PCI1 will trigger if any enabled PCINT[11:8] pin toggles. The PCMSK0 and PCMSK1 Registers control which pins contribute to the pin change interrupts. Pin change interrupts on PCINT[11:0] are detected asynchronously, which means that these interrupts can be used for waking the part also from sleep modes other than Idle mode. The INT0 interrupt can be triggered by a falling or rising edge or a low level. This is set up as shown in “MCUCR – MCU Control Register” on page 50. When the INT0 interrupt is enabled and configured as level triggered, the interrupt will trigger as long as the pin is held low. Note that recognition of falling or rising edge interrupts on INT0 requires the presence of an I/O clock, as described in “Clock Sources” on page 25. 9.2.1 Low Level Interrupt A low level interrupt on INT0 is detected asynchronously. This means that the interrupt source can be used for waking the part also from sleep modes other than Idle (the I/O clock is halted in all sleep modes except Idle).49 8183F–AVR–06/12 ATtiny24A/44A/84A Note that if a level triggered interrupt is used for wake-up from Power-down, the required level must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If the level disappears before the end of the Start-up Time, the MCU will still wake up, but no interrupt will be generated. The start-up time is defined by the SUT and CKSEL fuses, as described in “Clock System” on page 24. If the low level on the interrupt pin is removed before the device has woken up then program execution will not be diverted to the interrupt service routine but continue from the instruction following the SLEEP command. 9.2.2 Pin Change Interrupt Timing A timing example of a pin change interrupt is shown in Figure 9-1. Figure 9-1. Timing of pin change interrupts clk PCINT(0) pin_lat pin_sync pcint_in_(0) pcint_syn pcint_setflag PCIF PCINT(0) pin_sync pcint_syn pin_lat D Q LE pcint_setflag PCIF clk clk PCINT(0) in PCMSK(x) pcint_in_(0) 0 x50 8183F–AVR–06/12 ATtiny24A/44A/84A 9.3 Register Description 9.3.1 MCUCR – MCU Control Register The External Interrupt Control Register A contains control bits for interrupt sense control. • Bits 1:0 – ISC0[1:0]: Interrupt Sense Control 0 Bit 1 and Bit 0 The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set. The level and edges on the external INT0 pin that activate the interrupt are defined in Table 9-2. The value on the INT0 pin is sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. If low level interrupt is selected, the low level must be held until the completion of the currently executing instruction to generate an interrupt. 9.3.2 GIMSK – General Interrupt Mask Register • Bits 7, 3:0 – Res: Reserved Bits These bits are reserved in the ATtiny24A/44A and will always read as zero. • Bit 6 – INT0: External Interrupt Request 0 Enable When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is enabled. The Interrupt Sense Control bits (ISC01 and ISC00) in the External Interrupt Control Register A (EICRA) define whether the external interrupt is activated on rising and/or falling edge of the INT0 pin or level sensed. Activity on the pin will cause an interrupt request even if INT0 is configured as an output. The corresponding interrupt of External Interrupt Request 0 is executed from the INT0 Interrupt Vector. • Bit 5 – PCIE1: Pin Change Interrupt Enable 1 When the PCIE1 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin change interrupt 1 is enabled. Any change on any enabled PCINT[11:8] pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI1 Interrupt Vector. PCINT[11:8] pins are enabled individually by the PCMSK1 Register. Bit 7 6 5 4 3 2 1 0 0x35 (0x55) BODS PUD SE SM1 SM0 BODSE ISC01 ISC00 MCUCR Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 9-2. Interrupt 0 Sense Control ISC01 ISC00 Description 0 0 The low level of INT0 generates an interrupt request. 0 1 Any logical change on INT0 generates an interrupt request. 1 0 The falling edge of INT0 generates an interrupt request. 1 1 The rising edge of INT0 generates an interrupt request. Bit 7 6 5 4 3 2 1 0 0x3B (0x5B) – INT0 PCIE1 PCIE0 – – – – GIMSK Read/Write R R/W R/W R/W1 R R R R Initial Value 0 0 0 0 0 0 0 051 8183F–AVR–06/12 ATtiny24A/44A/84A • Bit 4 – PCIE0: Pin Change Interrupt Enable 0 When the PCIE0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin change interrupt 0 is enabled. Any change on any enabled PCINT[7:0] pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI0 Interrupt Vector. PCINT[7:0] pins are enabled individually by the PCMSK0 Register. 9.3.3 GIFR – General Interrupt Flag Register • Bits 7, 3:0 – Res: Reserved Bits These bits are reserved in the ATtiny24A/44A and will always read as zero. • Bit 6 – INTF0: External Interrupt Flag 0 When an edge or logic change on the INT0 pin triggers an interrupt request, INTF0 becomes set (one). If the I-bit in SREG and the INT0 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. This flag is always cleared when INT0 is configured as a level interrupt. • Bit 5 – PCIF1: Pin Change Interrupt Flag 1 When a logic change on any PCINT[11:8] pin triggers an interrupt request, PCIF1 becomes set (one). If the I-bit in SREG and the PCIE1 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. • Bit 4 – PCIF0: Pin Change Interrupt Flag 0 When a logic change on any PCINT[7:0] pin triggers an interrupt request, PCIF becomes set (one). If the I-bit in SREG and the PCIE0 bit in GIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. 9.3.4 PCMSK1 – Pin Change Mask Register 1 • Bits 7:4 – Res: Reserved Bits These bits are reserved in the ATtiny24A/44A and will always read as zero. • Bits 3:0 – PCINT[11:8]: Pin Change Enable Mask 11:8 Each PCINT[11:8] bit selects whether pin change interrupt is enabled on the corresponding I/O pin. If PCINT[11:8] is set and the PCIE1 bit in GIMSK is set, pin change interrupt is enabled on the corresponding I/O pin. If PCINT[11:8] is cleared, pin change interrupt on the corresponding I/O pin is disabled. Bit 7 6 5 4 3 2 1 0 0x3A (0x5A) – INTF0 PCIF1 PCIF0 – – – – GIFR Read/Write R R/W R/W R/W R R R R Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x20 (0x40) – – – – PCINT11 PCINT10 PCINT9 PCINT8 PCMSK1 Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 052 8183F–AVR–06/12 ATtiny24A/44A/84A 9.3.5 PCMSK0 – Pin Change Mask Register 0 • Bits 7:0 – PCINT[7:0]: Pin Change Enable Mask 7:0 Each PCINT[7:0] bit selects whether pin change interrupt is enabled on the corresponding I/O pin. If PCINT[7:0] is set and the PCIE0 bit in GIMSK is set, pin change interrupt is enabled on the corresponding I/O pin. If PCINT[7:0] is cleared, pin change interrupt on the corresponding I/O pin is disabled. Bit 7 6 5 4 3 2 1 0 0x12 (0x32) PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 PCMSK0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 053 8183F–AVR–06/12 ATtiny24A/44A/84A 10. I/O Ports All AVR ports have true Read-Modify-Write functionality when used as general digital I/O ports. This means that the direction of one port pin can be changed without unintentionally changing the direction of any other pin with the SBI and CBI instructions. The same applies when changing drive value (if configured as output) or enabling/disabling of pull-up resistors (if configured as input). Each output buffer has symmetrical drive characteristics with both high sink and source capability. The pin driver is strong enough to drive LED displays directly. All port pins have individually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O pins have protection diodes to both VCC and Ground as indicated in Figure 10-1 on page 53. See “Electrical Characteristics” on page 173 for a complete list of parameters. Figure 10-1. I/O Pin Equivalent Schematic All registers and bit references in this section are written in general form. A lower case “x” represents the numbering letter for the port, and a lower case “n” represents the bit number. However, when using the register or bit defines in a program, the precise form must be used. For example, PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O Registers and bit locations are listed in “Register Description” on page 66. Three I/O memory address locations are allocated for each port, one each for the Data Register – PORTx, Data Direction Register – DDRx, and the Port Input Pins – PINx. The Port Input Pins I/O location is read only, while the Data Register and the Data Direction Register are read/write. However, writing a logic one to a bit in the PINx Register, will result in a toggle in the corresponding bit in the Data Register. In addition, the Pull-up Disable – PUD bit in MCUCR disables the pull-up function for all pins in all ports when set. Using the I/O port as General Digital I/O is described in “Ports as General Digital I/O” on page 54. Most port pins are multiplexed with alternate functions for the peripheral features on the device. How each alternate function interferes with the port pin is described in “Alternate Port Functions” on page 58. Refer to the individual module sections for a full description of the alternate functions. Note that enabling the alternate function of some of the port pins does not affect the use of the other pins in the port as general digital I/O. Cpin Logic Rpu See Figure "General Digital I/O" for Details Pxn54 8183F–AVR–06/12 ATtiny24A/44A/84A 10.1 Ports as General Digital I/O The ports are bi-directional I/O ports with optional internal pull-ups. Figure 10-2 shows a functional description of one I/O-port pin, here generically called Pxn. Figure 10-2. General Digital I/O(1) Note: 1. WRx, WPx, WDx, RRx, RPx, and RDx are common to all pins within the same port. clkI/O, SLEEP, and PUD are common to all ports. 10.1.1 Configuring the Pin Each port pin consists of three register bits: DDxn, PORTxn, and PINxn. As shown in “Register Description” on page 66, the DDxn bits are accessed at the DDRx I/O address, the PORTxn bits at the PORTx I/O address, and the PINxn bits at the PINx I/O address. The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written logic one, Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is configured as an input pin. If PORTxn is written logic one when the pin is configured as an input pin, the pull-up resistor is activated. To switch the pull-up resistor off, PORTxn has to be written logic zero or the pin has to be configured as an output pin. The port pins are tri-stated when reset condition becomes active, even if no clocks are running. If PORTxn is written logic one when the pin is configured as an output pin, the port pin is driven high (one). If PORTxn is written logic zero when the pin is configured as an output pin, the port pin is driven low (zero). clk RPx RRx RDx WDx PUD SYNCHRONIZER WDx: WRITE DDRx WRx: WRITE PORTx RRx: READ PORTx REGISTER RPx: READ PORTx PIN PUD: PULLUP DISABLE clkI/O: I/O CLOCK RDx: READ DDRx D L Q Q RESET RESET Q D Q Q Q D CLR PORTxn Q Q D CLR DDxn PINxn DATA BU S SLEEP SLEEP: SLEEP CONTROL Pxn I/O WPx 0 1 WRx WPx: WRITE PINx REGISTER55 8183F–AVR–06/12 ATtiny24A/44A/84A 10.1.2 Toggling the Pin Writing a logic one to PINxn toggles the value of PORTxn, independent on the value of DDRxn. Note that the SBI instruction can be used to toggle one single bit in a port. 10.1.3 Switching Between Input and Output When switching between tri-state ({DDxn, PORTxn} = 0b00) and output high ({DDxn, PORTxn} = 0b11), an intermediate state with either pull-up enabled {DDxn, PORTxn} = 0b01) or output low ({DDxn, PORTxn} = 0b10) must occur. Normally, the pull-up enabled state is fully acceptable, as a high-impedant environment will not notice the difference between a strong high driver and a pull-up. If this is not the case, the PUD bit in the MCUCR Register can be set to disable all pull-ups in all ports. Switching between input with pull-up and output low generates the same problem. The user must use either the tri-state ({DDxn, PORTxn} = 0b00) or the output high state ({DDxn, PORTxn} = 0b10) as an intermediate step. Table 10-1 summarizes the control signals for the pin value. 10.1.4 Reading the Pin Value Independent of the setting of Data Direction bit DDxn, the port pin can be read through the PINxn Register bit. As shown in Figure 10-2 on page 54, the PINxn Register bit and the preceding latch constitute a synchronizer. This is needed to avoid metastability if the physical pin changes value near the edge of the internal clock, but it also introduces a delay. Figure 10-3 shows a timing diagram of the synchronization when reading an externally applied pin value. The maximum and minimum propagation delays are denoted tpd,max and tpd,min respectively. Figure 10-3. Synchronization when Reading an Externally Applied Pin value Table 10-1. Port Pin Configurations DDxn PORTxn PUD (in MCUCR) I/O Pull-up Comment 0 0 X Input No Tri-state (Hi-Z) 0 1 0 Input Yes Pxn will source current if ext. pulled low 0 1 1 Input No Tri-state (Hi-Z) 1 0 X Output No Output Low (Sink) 1 1 X Output No Output High (Source) XXX in r17, PINx 0x00 0xFF INSTRUCTIONS SYNC LATCH PINxn r17 XXX SYSTEM CLK tpd, max tpd, min56 8183F–AVR–06/12 ATtiny24A/44A/84A Consider the clock period starting shortly after the first falling edge of the system clock. The latch is closed when the clock is low, and goes transparent when the clock is high, as indicated by the shaded region of the “SYNC LATCH” signal. The signal value is latched when the system clock goes low. It is clocked into the PINxn Register at the succeeding positive clock edge. As indicated by the two arrows tpd,max and tpd,min, a single signal transition on the pin will be delayed between ½ and 1½ system clock period depending upon the time of assertion. When reading back a software assigned pin value, a nop instruction must be inserted as indicated in Figure 10-4 on page 56. The out instruction sets the “SYNC LATCH” signal at the positive edge of the clock. In this case, the delay tpd through the synchronizer is one system clock period. Figure 10-4. Synchronization when Reading a Software Assigned Pin Value 10.1.5 Digital Input Enable and Sleep Modes As shown in Figure 10-2 on page 54, the digital input signal can be clamped to ground at the input of the schmitt-trigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep Controller in Power-down and Standby modes to avoid high power consumption if some input signals are left floating, or have an analog signal level close to VCC/2. SLEEP is overridden for port pins enabled as external interrupt pins. If the external interrupt request is not enabled, SLEEP is active also for these pins. SLEEP is also overridden by various other alternate functions as described in “Alternate Port Functions” on page 58. If a logic high level (“one”) is present on an asynchronous external interrupt pin configured as “Interrupt on Rising Edge, Falling Edge, or Any Logic Change on Pin” while the external interrupt is not enabled, the corresponding External Interrupt Flag will be set when resuming from the above mentioned Sleep mode, as the clamping in these sleep mode produces the requested logic change. 10.1.6 Unconnected Pins If some pins are unused, it is recommended to ensure that these pins have a defined level. Even though most of the digital inputs are disabled in the deep sleep modes as described above, floating inputs should be avoided to reduce current consumption in all other modes where the digital inputs are enabled (Reset, Active mode and Idle mode). The simplest method to ensure a defined level of an unused pin, is to enable the internal pull-up. In this case, the pull-up will be disabled during reset. If low power consumption during reset is out PORTx, r16 nop in r17, PINx 0xFF 0x00 0xFF SYSTEM CLK r16 INSTRUCTIONS SYNC LATCH PINxn r17 t pd57 8183F–AVR–06/12 ATtiny24A/44A/84A important, it is recommended to use an external pull-up or pulldown. Connecting unused pins directly to VCC or GND is not recommended, since this may cause excessive currents if the pin is accidentally configured as an output. 10.1.7 Program Examples The following code example shows how to set port A pins 0 and 1 high, 2 and 3 low, and define the port pins from 4 to 5 as input with a pull-up assigned to port pin 4. The resulting pin values are read back again, but as previously discussed, a nop instruction is included to be able to read back the value recently assigned to some of the pins. Note: Two temporary registers are used to minimize the time from pull-ups are set on pins 0, 1 and 4, until the direction bits are correctly set, defining bit 2 and 3 as low and redefining bits 0 and 1 as strong high drivers. Note: See “Code Examples” on page 6. Assembly Code Example ... ; Define pull-ups and set outputs high ; Define directions for port pins ldi r16,(1< MSB MSB 6 5 4 3 2 1 LSB 1 2 3 4 5 6 7 8 6 5 4 3 2 1 LSB USCK USCK DO DI A B C D E CYCLE ( Reference )119 8183F–AVR–06/12 ATtiny24A/44A/84A SPITransfer_loop: out USICR,r17 in r16, USISR sbrs r16, USIOIF rjmp SPITransfer_loop in r16,USIDR ret The code is size optimized using only eight instructions (plus return). The code example assumes that the DO and USCK pins have been enabled as outputs in DDRA. The value stored in register r16 prior to the function is called is transferred to the slave device, and when the transfer is completed the data received from the slave is stored back into the register r16. The second and third instructions clear the USI Counter Overflow Flag and the USI counter value. The fourth and fifth instructions set three-wire mode, positive edge clock, count at USITC strobe, and toggle USCK. The loop is repeated 16 times. The following code demonstrates how to use the USI as an SPI master with maximum speed (fSCK = fCK/2): SPITransfer_Fast: out USIDR,r16 ldi r16,(1< 2 CPU clock cycles for fck < 12 MHz, 3 CPU clock cycles for fck >= 12 MHz • High:> 2 CPU clock cycles for fck < 12 MHz, 3 CPU clock cycles for fck >= 12 MHz 19.5.1 Serial Programming Algorithm When writing serial data to the ATtiny24A/44A/84A, data is clocked on the rising edge of SCK. When reading, data is clocked on the falling edge of SCK. See Figure 20-3 and Figure 20-4 for timing details. To program and verify the ATtiny24A/44A/84A in the Serial Programming mode, the following sequence is recommended (see four byte instruction formats in Table 19-12): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to “0”. In some systems, the programmer can not guarantee that SCK is held low during power-up. In this case, RESET must be given a positive pulse after SCK has been set to '0'. The duration of the pulse must be at least tRST (the minimum pulse width on RESET pin, see Table 20-4 on page 176) plus two CPU clock cycles. 2. Wait for at least 20 ms and enable serial programming by sending the Programming Enable serial instruction to pin MOSI. 3. The serial programming instructions will not work if the communication is out of synchronization. When in sync. the second byte (0x53), will echo back when issuing the third byte of the Programming Enable instruction. Whether the echo is correct or not, all four bytes of the instruction must be transmitted. If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command. 4. The Flash is programmed one page at a time. The memory page is loaded one byte at a time by supplying the 5 LSB of the address and data together with the Load Program memory Page instruction. To ensure correct loading of the page, the data low byte must be loaded before data high byte is applied for a given address. The Program memory Page is stored by loading the Write Program memory Page instruction with the 3 MSB of the address. If polling (RDY/BSY) is not used, the user must wait at least tWD_FLASH before issuing the next page. (See Table 19-11 on page 164.) Accessing the serial programming interface before the Flash write operation completes can result in incorrect programming. 5. A: The EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. If polling (RDY/BSY) is not used, the user must wait at least tWD_EEPROM before issuing the next byte. (See Table 19-11 on page 164.) In a chip erased device, no 0xFFs in the data file(s) need to be programmed. B: The EEPROM array is programmed one page at a time. The Memory page is loaded one byte at a time by supplying the 2 LSB of the address and data together with the Load EEPROM Memory Page instruction. The EEPROM Memory Page is stored by loading the Write EEPROM Memory Page Instruction with the 4 MSB of the address. When using EEPROM page access only byte locations loaded with the Load EEPROM Memory Page instruction is altered. The remaining locations remain unchanged. If polling (RDY/BSY) is not used, the used must wait at least tWD_EEPROM before issuing the next page (See Table 19-11 on page 164). In a chip erased device, no 0xFF in the data file(s) need to be programmed. 6. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO.164 8183F–AVR–06/12 ATtiny24A/44A/84A 7. At the end of the programming session, RESET can be set high to commence normal operation. 8. Power-off sequence (if needed): Set RESET to “1”. Turn VCC power off. 19.5.2 Serial Programming Instruction set The instruction set is described in Table 19-12 and Figure 19-2 on page 165. Table 19-11. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location Symbol Minimum Wait Delay tWD_FLASH 4.5 ms tWD_EEPROM 4.0 ms tWD_ERASE 9.0 ms tWD_FUSE 4.5 ms Table 19-12. Serial Programming Instruction Set Instruction/Operation(1) Instruction Format Byte 1 Byte 2 Byte 3 Byte4 Programming Enable $AC $53 $00 $00 Chip Erase (Program Memory/EEPROM) $AC $80 $00 $00 Poll RDY/BSY $F0 $00 $00 data byte out Load Instructions Load Extended Address byte $4D $00 Extended adr $00 Load Program Memory Page, High byte $48 adr MSB adr LSB high data byte in Load Program Memory Page, Low byte $40 adr MSB adr LSB low data byte in Load EEPROM Memory Page (page access) $C1 $00 adr LSB data byte in Read Instructions Read Program Memory, High byte $28 adr MSB adr LSB high data byte out Read Program Memory, Low byte $20 adr MSB adr LSB low data byte out Read EEPROM Memory $A0 $00 adr LSB data byte out Read Lock bits $58 $00 $00 data byte out Read Signature Byte $30 $00 adr LSB data byte out Read Fuse bits $50 $00 $00 data byte out Read Fuse High bits $58 $08 $00 data byte out Read Extended Fuse Bits $50 $08 $00 data byte out Read Calibration Byte $38 $00 $00 data byte out Write Instructions(6) Write Program Memory Page $4C adr MSB adr LSB $00 Write EEPROM Memory $C0 $00 adr LSB data byte in Write EEPROM Memory Page (page access) $C2 $00 adr LSB $00165 8183F–AVR–06/12 ATtiny24A/44A/84A Notes: 1. Not all instructions are applicable for all parts. 2. a = address 3. Bits are programmed ‘0’, unprogrammed ‘1’. 4. To ensure future compatibility, unused Fuses and Lock bits should be unprogrammed (‘1’) . 5. Refer to the correspondig section for Fuse and Lock bits, Calibration and Signature bytes and Page size. 6. Instructions accessing program memory use a word address. This address may be random within the page range. 7. See http://www.atmel.com/avr for Application Notes regarding programming and programmers. Figure 19-2. Serial Programming Instruction example If the LSB in RDY/BSY data byte out is ‘1’, a programming operation is still pending. Wait until this bit returns ‘0’ before the next instruction is carried out. Within the same page, the low data byte must be loaded prior to the high data byte. Write Lock bits $AC $E0 $00 data byte in Write Fuse bits $AC $A0 $00 data byte in Write Fuse High bits $AC $A8 $00 data byte in Write Extended Fuse Bits $AC $A4 $00 data byte in Table 19-12. Serial Programming Instruction Set (Continued) Instruction/Operation(1) Instruction Format Byte 1 Byte 2 Byte 3 Byte4 Byte 1 Byte 2 Byte 3 Byte 4 Adr MSB Adr LSB Bit 15 B 0 Serial Programming Instruction Program Memory/ EEPROM Memory Page 0 Page 1 Page 2 Page N-1 Page Buffer Write Program Memory Page/ Write EEPROM Memory Page Load Program Memory Page (High/Low Byte)/ Load EEPROM Memory Page (page access) Byte 1 Byte 2 Byte 3 Byte 4 Bit 15 B 0 Adr MSB Adr LSB Page Offset Page Number Adr MSB Adr LSB166 8183F–AVR–06/12 ATtiny24A/44A/84A After data is loaded to the page buffer, program the EEPROM page, see Figure 19-2 on page 165. 19.6 High-voltage Serial Programming This section describes how to program and verify Flash Program memory, EEPROM Data memory, Lock bits and Fuse bits in the ATtiny24A/44A/84A. Figure 19-3. High-voltage Serial Programming The minimum period for the Serial Clock Input (SCI) during High-voltage Serial Programming is 220 ns. 19.7 High-Voltage Serial Programming Algorithm To program and verify the ATtiny24A/44A/84A in the High-voltage Serial Programming mode, the following sequence is recommended (See instruction formats in Table 19-16 on page 170): Table 19-13. Pin Name Mapping Signal Name in High-voltage Serial Programming Mode Pin Name I/O Function SDI PA6 I Serial Data Input SII PA5 I Serial Instruction Input SDO PA4 O Serial Data Output SCI PB0 I Serial Clock Input (min. 220ns period) Table 19-14. Pin Values Used to Enter Programming Mode Pin Symbol Value PA0 Prog_enable[0] 0 PA1 Prog_enable[1] 0 PA2 Prog_enable[2] 0 VCC GND SDO SII SDI (RESET) +4.5 - 5.5V PA6 PA5 PA4 PB3 +11.5 - 12.5V SCI PB0 PA2:0167 8183F–AVR–06/12 ATtiny24A/44A/84A 19.7.1 Enter High-voltage Serial Programming Mode The following algorithm puts the device in High-voltage Serial Programming mode: 1. Set Prog_enable pins listed in Table 19-14 on page 166 to “000”, RESET pin and VCC to 0V. 2. Apply 4.5 - 5.5V between VCC and GND. Ensure that VCC reaches at least 1.8V within the next 20 µs. 3. Wait 20 - 60 µs, and apply 11.5 - 12.5V to RESET. 4. Keep the Prog_enable pins unchanged for at least 10 µs after the High-voltage has been applied to ensure the Prog_enable Signature has been latched. 5. Release the Prog_enable[2] pin after tHVRST has elapsed. 6. Wait at least 300 µs before giving any serial instructions on SDI/SII. 7. Exit Programming mode by power the device down or by bringing RESET pin to 0V. If the rise time of the VCC is unable to fulfill the requirements listed above, the following alternative algorithm can be used: 1. Set Prog_enable pins listed in Table 19-14 on page 166 to “000”, RESET pin and VCC to 0V. 2. Apply 4.5 - 5.5V between VCC and GND. 3. Monitor VCC, and as soon as VCC reaches 0.9 - 1.1V, apply 11.5 - 12.5V to RESET. 4. Keep the Prog_enable pins unchanged for at least 10 µs after the High-voltage has been applied to ensure the Prog_enable Signature has been latched. 5. Release the Prog_enable[2] pin to avoid drive contention on the Prog_enable[2]/SDO pin. 6. Wait until VCC actually reaches 4.5 - 5.5V before giving any serial instructions on SDI/SII. 7. Exit Programming mode by power the device down or by bringing RESET pin to 0V. Table 19-15. High-voltage Reset Characteristics Supply Voltage RESET Pin High-voltage Threshold Minimum High-voltage Period for Latching Prog_enable VCC VHVRST tHVRST 4.5V 11.5V 100 ns 5.5V 11.5V 100 ns168 8183F–AVR–06/12 ATtiny24A/44A/84A 19.7.2 Considerations for Efficient Programming The loaded command and address are retained in the device during programming. For efficient programming, the following should be considered. • The command needs only be loaded once when writing or reading multiple memory locations. • Skip writing the data value 0xFF that is the contents of the entire EEPROM (unless the EESAVE Fuse is programmed) and Flash after a Chip Erase. • Address High byte needs only be loaded before programming or reading a new 256 word window in Flash or 256 byte EEPROM. This consideration also applies to Signature bytes reading. 19.7.3 Chip Erase The Chip Erase will erase the Flash and EEPROM(1) memories plus Lock bits. The Lock bits are not reset until the Program memory has been completely erased. The Fuse bits are not changed. A Chip Erase must be performed before the Flash and/or EEPROM are reprogrammed. 1. Load command “Chip Erase” (see Table 19-16 on page 170). 2. Wait after Instr. 3 until SDO goes high for the “Chip Erase” cycle to finish. 3. Load Command “No Operation”. Note: 1. The EEPROM memory is preserved during Chip Erase if the EESAVE Fuse is programmed. 19.7.4 Programming the Flash The Flash is organized in pages, see “Page Size” on page 161. When programming the Flash, the program data is latched into a page buffer. This allows one page of program data to be programmed simultaneously. The following procedure describes how to program the entire Flash memory: 1. Load Command “Write Flash” (see Table 19-16 on page 170). 2. Load Flash Page Buffer. 3. Load Flash High Address and Program Page. Wait after Instr. 3 until SDO goes high for the “Page Programming” cycle to finish. 4. Repeat 2 through 3 until the entire Flash is programmed or until all data has been programmed. 5. End Page Programming by Loading Command “No Operation”. When writing or reading serial data to the ATtiny24A/44A/84A, data is clocked on the rising edge of the serial clock, see Figure 20-5 on page 181, Figure 19-3 on page 166 and Table 20-12 on page 181 for details.169 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 19-4. Addressing the Flash which is Organized in Pages Figure 19-5. High-voltage Serial Programming Waveforms 19.7.5 Programming the EEPROM The EEPROM is organized in pages, see Table 20-11 on page 180. When programming the EEPROM, the data is latched into a page buffer. This allows one page of data to be programmed simultaneously. The programming algorithm for the EEPROM Data memory is as follows (refer to Table 19-16 on page 170): 1. Load Command “Write EEPROM”. 2. Load EEPROM Page Buffer. 3. Program EEPROM Page. Wait after Instr. 2 until SDO goes high for the “Page Programming” cycle to finish. 4. Repeat 2 through 3 until the entire EEPROM is programmed or until all data has been programmed. 5. End Page Programming by Loading Command “No Operation”. PROGRAM MEMORY WORD ADDRESS WITHIN A PAGE PAGE ADDRESS WITHIN THE FLASH INSTRUCTION WORD PAGE PCWORD[PAGEMSB:0]: 00 01 02 PAGEEND PAGE PCPAGE PCWORD PCMSB PAGEMSB PROGRAM COUNTER MSB MSB MSB LSB LSB LSB 0 1 2 3 4 5 6 7 8 9 10 SDI PA6 SII PA5 SDO PA4 SCI PB0170 8183F–AVR–06/12 ATtiny24A/44A/84A 19.7.6 Reading the Flash The algorithm for reading the Flash memory is as follows (refer to Table 19-16 on page 170): 1. Load Command "Read Flash". 2. Read Flash Low and High Bytes. The contents at the selected address are available at serial output SDO. 19.7.7 Reading the EEPROM The algorithm for reading the EEPROM memory is as follows (refer to Table 19-16 on page 170): 1. Load Command “Read EEPROM”. 2. Read EEPROM Byte. The contents at the selected address are available at serial output SDO. 19.7.8 Programming and Reading the Fuse and Lock Bits The algorithms for programming and reading the Fuse Low/High bits and Lock bits are shown in Table 19-16 on page 170. 19.7.9 Reading the Signature Bytes and Calibration Byte The algorithms for reading the Signature bytes and Calibration byte are shown in Table 19-16 on page 170. 19.7.10 Power-off sequence Set SCI to “0”. Set RESET to “1”. Turn VCC power off. Table 19-16. High-voltage Serial Programming Instruction Set for ATtiny24A/44A/84A Instruction Instruction Format Instr.1/5 Instr.2/6 Instr.3/7 Instr.4 Operation Remarks Chip Erase SDI SII SDO 0_1000_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Wait after Instr.3 until SDO goes high for the Chip Erase cycle to finish. Load “Write Flash” Command SDI SII SDO 0_0001_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx Enter Flash Programming code. Load Flash Page Buffer SDI SII SDO 0_ bbbb_bbbb _00 0_0000_1100_00 x_xxxx_xxxx_xx 0_eeee_eeee_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1101_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Repeat after Instr. 1 - 7until the entire page buffer is filled or until all data within the page is filled.(2) SDI SII SDO 0_dddd_dddd_00 0_0011_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1101_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1100_00 x_xxxx_xxxx_xx Instr 5-7. Load Flash High Address and Program Page SDI SII SDO 0_0000_000a_00 0_0001_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Wait after Instr 3 until SDO goes high. Repeat Instr. 2 - 3 for each loaded Flash Page until the entire Flash or all data is programmed. Repeat Instr. 1 for a new 256 byte page.(2)171 8183F–AVR–06/12 ATtiny24A/44A/84A Load “Read Flash” Command SDI SII SDO 0_0000_0010_00 0_0100_1100_00 x_xxxx_xxxx_xx Enter Flash Read mode. Read Flash Low and High Bytes SDI SII SDO 0_bbbb_bbbb_00 0_0000_1100_00 x_xxxx_xxxx_xx 0_0000_000a_00 0_0001_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 q_qqqq_qqqx_xx Repeat Instr. 1, 3 - 6 for each new address. Repeat Instr. 2 for a new 256 byte page. SDI SII SDO 0_0000_0000_00 0_0111_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1100_00 p_pppp_pppx_xx Instr 5 - 6. Load “Write EEPROM” Command SDI SII SDO 0_0001_0001_00 0_0100_1100_00 x_xxxx_xxxx_xx Enter EEPROM Programming mode. Load EEPROM Page Buffer SDI SII SDO 0_bbbb_bbbb_00 0_0000_1100_00 x_xxxx_xxxx_xx 0_aaaa_aaaa_00 0_0001_1100_00 x_xxxx_xxxx_xx 0_eeee_eeee_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1101_00 x_xxxx_xxxx_xx Repeat Instr. 1 - 5 until the entire page buffer is filled or until all data within the page is filled.(3) SDI SII SDO 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Program EEPROM Page SDI SII SDO 0_0000_0000_00 0_0110_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Wait after Instr. 2 until SDO goes high. Repeat Instr. 1 - 2 for each loaded EEPROM page until the entire EEPROM or all data is programmed. Write EEPROM Byte SDI SII SDO 0_bbbb_bbbb_00 0_0000_1100_00 x_xxxx_xxxx_xx 0_aaaa_aaaa_00 0_0001_1100_00 x_xxxx_xxxx_xx 0_eeee_eeee_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1101_00 x_xxxx_xxxx_xx Repeat Instr. 1 - 6 for each new address. Wait after Instr. 6 until SDO goes high.(4) SDI SII SDO 0_0000_0000_00 0_0110_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Instr. 5-6 Load “Read EEPROM” Command SDI SII SDO 0_0000_0011_00 0_0100_1100_00 x_xxxx_xxxx_xx Enter EEPROM Read mode. Read EEPROM Byte SDI SII SDO 0_bbbb_bbbb_00 0_0000_1100_00 x_xxxx_xxxx_xx 0_aaaa_aaaa_00 0_0001_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 q_qqqq_qqq0_00 Repeat Instr. 1, 3 - 4 for each new address. Repeat Instr. 2 for a new 256 byte page. Write Fuse Low Bits SDI SII SDO 0_0100_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_A987_6543_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Wait after Instr. 4 until SDO goes high. Write A - 3 = “0” to program the Fuse bit. Write Fuse High Bits SDI SII SDO 0_0100_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_IHGF_EDCB_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1100_00 x_xxxx_xxxx_xx Wait after Instr. 4 until SDO goes high. Write F - B = “0” to program the Fuse bit. Write Fuse Extended Bits SDI SII SDO 0_0100_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_000J_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_0110_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1110_00 x_xxxx_xxxx_xx Wait after Instr. 4 until SDO goes high. Write J = “0” to program the Fuse bit. Table 19-16. High-voltage Serial Programming Instruction Set for ATtiny24A/44A/84A (Continued) Instruction Instruction Format Instr.1/5 Instr.2/6 Instr.3/7 Instr.4 Operation Remarks172 8183F–AVR–06/12 ATtiny24A/44A/84A Notes: 1. a = address high bits, b = address low bits, d = data in high bits, e = data in low bits, p = data out high bits, q = data out low bits, x = don’t care, 1 = Lock Bit1, 2 = Lock Bit2, 3 = CKSEL0 Fuse, 4 = CKSEL1 Fuse, 5 = CKSEL2 Fuse, 6 = CKSEL3 Fuse, 7 = SUT0 Fuse, 8 = SUT1 Fuse, 9 = CKOUT Fuse, A = CKDIV8 Fuse, B = BODLEVEL0 Fuse, C = BODLEVEL1 Fuse, D= BODLEVEL2 Fuse, E = EESAVE Fuse, F = WDTON Fuse, G = SPIEN Fuse, H = DWEN Fuse, I = RSTDISBL Fuse, J = SELFPRGEN Fuse 2. For page sizes less than 256 words, parts of the address (bbbb_bbbb) will be parts of the page address. 3. For page sizes less than 256 bytes, parts of the address (bbbb_bbbb) will be parts of the page address. 4. The EEPROM is written page-wise. But only the bytes that are loaded into the page are actually written to the EEPROM. Page-wise EEPROM access is more efficient when multiple bytes are to be written to the same page. Note that auto-erase of EEPROM is not available in High-voltage Serial Programming, only in SPI Programming. Write Lock Bits SDI SII SDO 0_0010_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0021_00 0_0010_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_0100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_xxxx_xx Wait after Instr. 4 until SDO goes high. Write 2 - 1 = “0” to program the Lock Bit. Read Fuse Low Bits SDI SII SDO 0_0000_0100_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 A_9876_543x_xx Reading A - 3 = “0” means the Fuse bit is programmed. Read Fuse High Bits SDI SII SDO 0_0000_0100_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1010_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1100_00 I_HGFE_DCBx_xx Reading F - B = “0” means the Fuse bit is programmed. Read Fuse Extended Bits SDI SII SDO 0_0000_0100_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1010_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1110_00 x_xxxx_xxJx_xx Reading J = “0” means the Fuse bit is programmed. Read Lock Bits SDI SII SDO 0_0000_0100_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 x_xxxx_x21x_xx Reading 2, 1 = “0” means the Lock bit is programmed. Read Signature Bytes SDI SII SDO 0_0000_1000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_00bb_00 0_0000_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0110_1100_00 q_qqqq_qqqx_xx Repeats Instr 2 4 for each signature byte address. Read Calibration Byte SDI SII SDO 0_0000_1000_00 0_0100_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0000_1100_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1000_00 x_xxxx_xxxx_xx 0_0000_0000_00 0_0111_1100_00 p_pppp_pppx_xx Load “No Operation” Command SDI SII SDO 0_0000_0000_00 0_0100_1100_00 x_xxxx_xxxx_xx Table 19-16. High-voltage Serial Programming Instruction Set for ATtiny24A/44A/84A (Continued) Instruction Instruction Format Instr.1/5 Instr.2/6 Instr.3/7 Instr.4 Operation Remarks173 8183F–AVR–06/12 ATtiny24A/44A/84A 20. Electrical Characteristics 20.1 Absolute Maximum Ratings* 20.2 DC Characteristics Operating Temperature.................................. -55°C to +125°C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ............................................... 40.0 mA DC Current VCC and GND Pins ................................ 200.0 mA Table 20-1. DC Characteristics. TA = -40°C to +85°C Symbol Parameter Condition Min Typ(1) Max Units VIL Input Low Voltage VCC = 1.8V - 2.4V -0.5 0.2VCC(3) V VCC = 2.4V - 5.5V -0.5 0.3VCC(3) V Input Low Voltage, RESET Pin as Reset (4) VCC = 1.8V - 5.5 -0.5 0.2VCC(3) VIH Input High-voltage Except RESET pin VCC = 1.8V - 2.4V 0.7VCC(2) VCC +0.5 V VCC = 2.4V - 5.5V 0.6VCC(2) VCC +0.5 V Input High-voltage RESET pin as Reset (4) VCC = 1.8V to 5.5V 0.9VCC(2) VCC +0.5 V VOL Output Low Voltage (5) Except RESET pin (7) IOL = 10 mA, VCC = 5V 0.6 V IOL = 5 mA, VCC = 3V 0.5 V VOH Output High-voltage (6) Except RESET pin (7) IOH = -10 mA, VCC = 5V 4.3 V IOH = -5 mA, VCC = 3V 2.5 V ILIL Input Leakage Current I/O Pin VCC = 5.5V, pin low (absolute value) < 0.05 1(8) µA ILIH Input Leakage Current I/O Pin VCC = 5.5V, pin high (absolute value) < 0.05 1(8) µA RPU Pull-up Resistor, I/O Pin VCC = 5.5V, input low 20 50 kΩ Pull-up Resistor, Reset Pin VCC = 5.5V, input low 30 60 kΩ174 8183F–AVR–06/12 ATtiny24A/44A/84A Notes: 1. Typical values at 25°C. 2. “Min” means the lowest value where the pin is guaranteed to be read as high. 3. “Max” means the highest value where the pin is guaranteed to be read as low. 4. Not tested in production. 5. Although each I/O port can sink more than the test conditions (10 mA at VCC = 5V, 5 mA at VCC = 3V) under steady state conditions (non-transient), the sum of all IOL (for all ports) should not exceed 60 mA. If IOL exceeds the test conditions, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 6. Although each I/O port can source more than the test conditions (10 mA at VCC = 5V, 5 mA at VCC = 3V) under steady state conditions (non-transient), the sum of all IOH (for all ports) should not exceed 60 mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 7. The RESET pin must tolerate high voltages when entering and operating in programming modes and, as a consequence, has a weak drive strength as compared to regular I/O pins. See Figure 21-87, Figure 21-88, Figure 21-89, and Figure 21-90 (starting on page 226). 8. These are test limits, which account for leakage currents of the test environment. Actual device leakage currents are lower. 9. Values are with external clock using methods described in “Minimizing Power Consumption” on page 35. Power Reduction is enabled (PRR = 0xFF) and there is no I/O drive. 10. BOD Disabled. 20.3 Speed The maximum operating frequency of the device depends on VCC. As shown in Figure 20-1, the relationship between maximum frequency and VCC is linear in the region 1.8V < VCC < 4.5V. Figure 20-1. Maximum Frequency vs. VCC ICC Supply Current, Active Mode (9) f = 1 MHz, VCC = 2V 0.25 0.5 mA f = 4 MHz, VCC = 3V 1.2 2 mA f = 8 MHz, VCC = 5V 4.4 7 mA Supply Current, Idle Mode (9) f = 1 MHz, VCC = 2V 0.04 0.2 mA f = 4 MHz, VCC = 3V 0.25 0.6 mA f = 8 MHz, VCC = 5V 1.3 2 mA Supply Current, Power-Down Mode (10) WDT enabled, VCC = 3V 4 10 µA WDT disabled, VCC = 3V 0.13 2 µA Table 20-1. DC Characteristics. TA = -40°C to +85°C (Continued) Symbol Parameter Condition Min Typ(1) Max Units 4 MHz 1.8V 5.5V 4.5V 20 MHz175 8183F–AVR–06/12 ATtiny24A/44A/84A 20.4 Clock Characteristics 20.4.1 Accuracy of Calibrated Internal Oscillator It is possible to manually calibrate the internal oscillator to be more accurate than default factory calibration. Note that the oscillator frequency depends on temperature and voltage. Voltage and temperature characteristics can be found in Figure 21-109 on page 237 and Figure 21-110 on page 238. Notes: 1. Accuracy of oscillator frequency at calibration point (fixed temperature and fixed voltage). 20.4.2 External Clock Drive Figure 20-2. External Clock Drive Waveform Table 20-2. Calibration Accuracy of Internal RC Oscillator Calibration Method Target Frequency VCC Temperature Accuracy at given voltage & temperature (1) Factory Calibration 8.0 MHz 3V 25°C ±10% User Calibration Fixed frequency within: 7.3 – 8.1 MHz Fixed voltage within: 1.8V – 5.5V Fixed temperature within: -40°C to +85°C ±1% VIL1 VIH1 Table 20-3. External Clock Drive Characteristics Symbol Parameter VCC = 1.8 - 5.5V VCC = 2.7 - 5.5V VCC = 4.5 - 5.5V Min. Max. Min. Max. Min. Max. Units 1/tCLCL Clock Frequency 0 4 0 10 0 20 MHz tCLCL Clock Period 250 100 50 ns tCHCX High Time 100 40 20 ns tCLCX Low Time 100 40 20 ns tCLCH Rise Time 2.0 1.6 0.5 µs tCHCL Fall Time 2.0 1.6 0.5 µs ΔtCLCL Change in period from one clock cycle to the next 2 2 2 %176 8183F–AVR–06/12 ATtiny24A/44A/84A 20.5 System and Reset Characteristics Note: 1. Values are guidelines, only 20.5.1 Power-On Reset Note: 1. Values are guidelines, only 2. Threshold where device is released from reset when voltage is rising 3. The Power-on Reset will not work unless the supply voltage has been below VPOA 20.5.2 Brown-Out Detection Note: 1. VBOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is tested down to VCC = VBOT during the production test. This guarantees that a Brown-out Reset will occur before VCC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. Table 20-4. Reset, Brown-out, and Internal Voltage Characteristics Symbol Parameter Condition Min(1) Typ(1) Max(1) Units VRST RESET pin threshold voltage 0.2 VCC 0.9VCC V tRST Minimum pulse width on RESET pin VCC = 1.8V VCC = 3V VCC = 5V 2000 700 400 ns VHYST Brown-out Detector hysteresis 50 mV tBOD Minimum pulse width on Brown-out Reset 2 µs VBG Internal bandgap reference voltage VCC = 5V TA = 25°C 1.0 1.1 1.2 V tBG Internal bandgap reference start-up time VCC = 5V TA = 25°C 40 70 µs IBG Internal bandgap reference current consumption VCC = 5V TA = 25°C 15 µA Table 20-5. Characteristics of Enhanced Power-On Reset. TA = = -40°C to +85°C Symbol Parameter Min(1) Typ(1) Max(1) Units VPOR Release threshold of power-on reset (2) 1.1 1.4 1.6 V VPOA Activation threshold of power-on reset (3) 0.6 1.3 1.6 V SRON Power-On Slope Rate 0.01 V/ms Table 20-6. VBOT vs. BODLEVEL Fuse Coding BODLEVEL[2:0] Fuses Min(1) Typ(1) Max(1) Units 111 BOD Disabled 110 1.7 1.8 2.0 101 2.5 2.7 2.9 V 100 4.1 4.3 4.5 0XX Reserved177 8183F–AVR–06/12 ATtiny24A/44A/84A 20.6 ADC Characteristics Table 20-7. ADC Characteristics, Single Ended Channels. T = -40°C to +85°C Symbol Parameter Condition Min Typ Max Units Resolution 10 Bits Absolute accuracy (Including INL, DNL, and Quantization, Gain and Offset Errors) VREF = 4V, VCC = 4V, ADC clock = 200 kHz 2.0 LSB VREF = 4V, VCC = 4V, ADC clock = 1 MHz 2.5 LSB VREF = 4V, VCC = 4V, ADC clock = 200 kHz Noise Reduction Mode 1.5 LSB VREF = 4V, VCC = 4V, ADC clock = 1 MHz Noise Reduction Mode 2.0 LSB Integral Non-Linearity (INL) (Accuracy after Offset and Gain Calibration) VREF = 4V, VCC = 4V, ADC clock = 200 kHz 1.0 LSB Differential Non-linearity (DNL) VREF = 4V, VCC = 4V, ADC clock = 200 kHz 0.5 LSB Gain Error VREF = 4V, VCC = 4V, ADC clock = 200 kHz 2.0 LSB Offset Error (Absolute) VREF = 4V, VCC = 4V, ADC clock = 200 kHz 1.5 LSB Conversion Time Free Running Conversion 14 280 µs Clock Frequency 50 1000 kHz VIN Input Voltage GND VREF V Input Bandwidth 38.5 kHz AREF External Voltage Reference 2.0 VCC V VINT Internal Voltage Reference 1.0 1.1 1.2 V RREF Reference Input Resistance 32 kΩ RAIN Analog Input Resistance 100 MΩ ADC Conversion Output 0 1023 LSB178 8183F–AVR–06/12 ATtiny24A/44A/84A Table 20-8. ADC Characteristics, Differential Channels (Unipolar Mode), TA = -40°C to +85°C Symbol Parameter Condition Min Typ Max Units Resolution Gain = 1x 10 Bits Gain = 20x 10 Bits Absolute accuracy (Including INL, DNL, and Quantization, Gain and Offset Errors) Gain = 1x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 10 LSB Gain = 20x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 15 LSB Integral Non-Linearity (INL) (Accuracy after Offset and Gain Calibration) Gain = 1x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 4 LSB Gain = 20x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 10 LSB Gain Error Gain = 1x 10 LSB Gain = 20x 15 LSB Offset Error Gain = 1x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 3 LSB Gain = 20x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 4 LSB Conversion Time Free Running Conversion 70 280 µs Clock Frequency 50 200 kHz VIN Input Voltage GND VCC V VDIFF Input Differential Voltage VREF/Gain V Input Bandwidth 4 kHz AREF External Reference Voltage 2.0 VCC - 1.0 V VINT Internal Voltage Reference 1.0 1.1 1.2 V RREF Reference Input Resistance 32 kΩ RAIN Analog Input Resistance 100 MΩ ADC Conversion Output 0 1023 LSB179 8183F–AVR–06/12 ATtiny24A/44A/84A Table 20-9. ADC Characteristics, Differential Channels (Bipolar Mode), TA = -40°C to +85°C Symbol Parameter Condition Min Typ Max Units Resolution Gain = 1x 10 Bits Gain = 20x 10 Bits Absolute accuracy (Including INL, DNL, and Quantization, Gain and Offset Errors) Gain = 1x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 8 LSB Gain = 20x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 8 LSB Integral Non-Linearity (INL) (Accuracy after Offset and Gain Calibration) Gain = 1x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 4 LSB Gain = 20x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 5 LSB Gain Error Gain = 1x 4 LSB Gain = 20x 5 LSB Offset Error Gain = 1x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 3 LSB Gain = 20x VREF = 4V, VCC = 5V ADC clock = 50 - 200 kHz 4 LSB Conversion Time Free Running Conversion 70 280 µs Clock Frequency 50 200 kHz VIN Input Voltage GND VCC V VDIFF Input Differential Voltage VREF/Gain V Input Bandwidth 4 kHz AREF External Reference Voltage 2.0 VCC - 1.0 V VINT Internal Voltage Reference 1.0 1.1 1.2 V RREF Reference Input Resistance 32 kΩ RAIN Analog Input Resistance 100 MΩ ADC Conversion Output -512 511 LSB180 8183F–AVR–06/12 ATtiny24A/44A/84A 20.7 Analog Comparator Characteristics Note: All parameters are based on simulation results and are not tested in production 20.8 Serial Programming Characteristics Figure 20-3. Serial Programming Timing Figure 20-4. Serial Programming Waveform Table 20-10. Analog Comparator Characteristics, TA = -40°C to +85°C Symbol Parameter Condition Min Typ Max Units VAIO Input Offset Voltage VCC = 5V, VIN = VCC / 2 < 10 40 mV ILAC Input Leakage Current VCC = 5V, VIN = VCC / 2 -50 50 nA tAPD Analog Propagation Delay (from saturation to slight overdrive) VCC = 2.7V 750 ns VCC = 4.0V 500 Analog Propagation Delay (large step change) VCC = 2.7V 100 VCC = 4.0V 75 tDPD Digital Propagation Delay VCC = 1.8V - 5.5 1 2 CLK Table 20-11. Serial Programming Characteristics, TA = -40°C to +85°C, VCC = 1.8 - 5.5V (Unless Otherwise Noted) Symbol Parameter Min Typ Max Units 1/tCLCL Oscillator Frequency 0 4 MHz tCLCL Oscillator Period 250 ns 1/tCLCL Oscillator Freq. (VCC = 4.5V - 5.5V) 0 20 MHz MOSI MISO SCK t OVSH t SHSL t t SHOX SLSH MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUT181 8183F–AVR–06/12 ATtiny24A/44A/84A Note: 1. 2 tCLCL for fck < 12 MHz, 3 tCLCL for fck >= 12 MHz 20.9 High-Voltage Serial Programming Characteristics Figure 20-5. High-voltage Serial Programming Timing tCLCL Oscillator Period (VCC = 4.5V - 5.5V) 50 ns tSHSL SCK Pulse Width High 2 tCLCL(1) ns tSLSH SCK Pulse Width Low 2 tCLCL(1) ns tOVSH MOSI Setup to SCK High tCLCL ns tSHOX MOSI Hold after SCK High 2 tCLCL ns Table 20-11. Serial Programming Characteristics, TA = -40°C to +85°C, VCC = 1.8 - 5.5V (Unless Otherwise Noted) Symbol Parameter Min Typ Max Units Table 20-12. High-voltage Serial Programming Characteristics TA = 25°C, VCC = 5V (Unless otherwise noted) Symbol Parameter Min Typ Max Units tSHSL SCI (PB0) Pulse Width High 125 ns tSLSH SCI (PB0) Pulse Width Low 125 ns tIVSH SDI (PA6), SII (PB1) Valid to SCI (PB0) High 50 ns tSHIX SDI (PA6), SII (PB1) Hold after SCI (PB0) High 50 ns tSHOV SCI (PB0) High to SDO (PA4) Valid 16 ns tWLWH_PFB Wait after Instr. 3 for Write Fuse Bits 2.5 ms SDI (PA6), SII (PA5) SDO (PA4) SCI (PB0) t IVSH t SHSL t t SHIX SLSH t SHOV182 8183F–AVR–06/12 ATtiny24A/44A/84A 21. Typical Characteristics The data contained in this section is largely based on simulations and characterization of similar devices in the same process and design methods. Thus, the data should be treated as indications of how the part will behave. The following charts show typical behavior. These figures are not tested during manufacturing. During characterisation devices are operated at frequencies higher than test limits but they are not guaranteed to function properly at frequencies higher than the ordering code indicates. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. Current consumption is a function of several factors such as operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. A sine wave generator with rail-to-rail output is used as clock source but current consumption in Power-Down mode is independent of clock selection. The difference between current consumption in Power-Down mode with Watchdog Timer enabled and Power-Down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. The current drawn from pins with a capacitive load may be estimated (for one pin) as follows: where VCC = operating voltage, CL = load capacitance and fSW = average switching frequency of I/O pin. 21.1 Supply Current of I/O Modules The tables and formulas below can be used to calculate the additional current consumption for the different I/O modules in Active and Idle mode. The enabling or disabling of the I/O modules is controlled by the Power Reduction Register. See “Power Reduction Register” on page 35 for details. Table 21-2 below can be used for calculating typical current consumption for other supply voltages and frequencies than those mentioned in the Table 21-1 above. I CP VCC CL × × f SW ≈ Table 21-1. Additional Current Consumption for the different I/O modules (absolute values) PRR bit Typical numbers VCC = 2V, f = 1 MHz VCC = 3V, f = 4 MHz VCC = 5V, f = 8 MHz PRTIM1 1.6 µA 11 µA 48 µA PRTIM0 4.4 µA 29 µA 120 µA PRUSI 1.6 µA 11 µA 48 µA PRADC 8.0 µA 55 µA 240 µA183 8183F–AVR–06/12 ATtiny24A/44A/84A 21.1.1 Example Calculate the expected current consumption in idle mode with USI, TIMER0, and ADC enabled at VCC = 2.0V and f = 1 MHz. From Table 21-2 on page 183, third column, we see that we need to add 5% for the USI, 10% for TIMER0, and 20% for the ADC. Reading from Figure 21-61 on page 213, we find that current consumption in idle mode at 2V and 1 MHz is about 0.04 mA. The total current consumption in idle mode with USI, TIMER0, and ADC enabled is therefore: 21.2 ATtiny24A 21.2.1 Current Consumption in Active Mode Figure 21-1. Active Supply Current vs. Low Frequency 0.1 - 1.0 MHz, PRR = 0xFF Table 21-2. Additional Current Consumption (percentage) in Active and Idle mode PRR bit Current consumption additional to active mode with external clock (see Figure 21-56 and Figure 21-57) Current consumption additional to idle mode with external clock (see Figure 21-61 and Figure 21-62) PRTIM1 1 % 5 % PRTIM0 3 % 10 % PRUSI 1 % 5 % PRADC 5 % 20 % ICCTOT ≈ ≈ 0,05mA × ( ) 1 0,05 0,10 0,20 +++ 0,06mA 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,2 0,4 0,6 0,8 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA)184 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-2. Active Supply Current vs. Frequency 1 - 20 MHz, PRR = 0xFF Figure 21-3. Active Supply Current vs. VCC Internal RC Oscillator, 8 MHz 0 2 4 6 8 10 12 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)185 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-4. Active Supply Current vs. VCC Internal RC Oscillator, 1 MHz Figure 21-5. Active Supply Current vs. VCC Internal RC Oscillator, 128 kHz 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)186 8183F–AVR–06/12 ATtiny24A/44A/84A 21.2.2 Current Consumption in Idle Mode Figure 21-6. Idle Supply Current vs. Low Frequency 0.1 - 1.0 MHz, PRR = 0xFF Figure 21-7. Idle Supply Current vs. Frequency 1 - 20 MHz, PRR = 0xFF 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) 0 0,5 1 1,5 2 2,5 3 3,5 4 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V187 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-8. Idle Supply Current vs. VCC Internal RC Oscillator, 8 MHz Figure 21-9. Idle Supply Current vs. VCC Internal RC Oscillator, 1 MHz 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)188 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-10. Idle Supply Current vs. VCC Internal RC Oscillator, 128 kHz 21.2.3 Current Consumption in Power-down Mode Figure 21-11. Power-down Supply Current vs. VCC Watchdog Timer Disabled 85 °C 25 °C -40 °C 0 0,005 0,01 0,015 0,02 0,025 0,03 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)189 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-12. Power-down Supply Current vs. VCC Watchdog Timer Enabled 21.2.4 Current Consumption in Reset Figure 21-13. Reset Supply Current vs. VCC 0.1 - 1.0 MHz, Excluding Current through Reset Pull-up 85 °C 25 °C -40 °C 0 2 4 6 8 10 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0,16 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA)190 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-14. Reset Supply Current vs. VCC 1 - 20 MHz, Excluding Current through Reset Pull-up 21.2.5 Current Consumption of Peripheral Units Figure 21-15. ADC Current vs. VCC 4 MHz Frequency 0 0,5 1 1,5 2 2,5 3 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 100 200 300 400 500 600 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)191 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-16. AREF Pin Current vs. Pin Voltage Figure 21-17. Analog Comparator Current vs. VCC 4 MHz Frequency 0 20 40 60 80 100 120 140 160 180 200 1,5 2 2,5 3 3,5 4 4,5 5 5,5 AREF (V) AREF pin current (uA) 0 20 40 60 80 100 120 140 160 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)192 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-18. Programming Current vs. VCC Figure 21-19. Brownout Detector Current vs. VCC BOD Level = 1.8V 85 °C 25 °C -40 °C 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 1,5 2,5 3,5 4,5 5,5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 40 45 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)193 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-20. Watchdog Timer Current vs. VCC 21.2.6 Pull-up Resistors Figure 21-21. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 1.8V 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 7 8 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 85 °C -40 °C 25 °C 0 10 20 30 40 50 60 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VOP (V) IOP (uA)194 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-22. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 2.7V Figure 21-23. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 5V 0 10 20 30 40 50 60 70 80 0 0,5 1 1,5 2 2,5 3 VOP (V) IOP (uA) 85 °C -40 °C 25 °C 0 20 40 60 80 100 120 140 160 0 1 2 3 4 5 6 VOP (V) IOP (uA) 85 °C -40 °C 25 °C195 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-24. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 1.8V Figure 21-25. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 2.7V 0 5 10 15 20 25 30 35 40 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VRESET (V) IRESET (uA) 85 °C -40 °C 25 °C 0 10 20 30 40 50 60 0 0,5 1 1,5 2 2,5 3 VRESET (V) IRESET (uA) 85 °C -40 °C 25 °C196 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-26. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 5V 21.2.7 Output Driver Strength Figure 21-27. VOL: Output Voltage vs. Sink Current I/O Pin, VCC = 3V 0 20 40 60 80 100 120 0 1 2 3 4 5 6 VRESET (V) IRESET (uA) 85 °C -40 °C 25 °C 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 0 5 10 15 20 IOL (mA) VOL (V)197 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-28. VOL: Output Voltage vs. Sink Current I/O Pin, VCC = 5V Figure 21-29. VOH: Output Voltage vs. Source Current I/O Pin, VCC = 3V 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0 5 10 15 20 IOL (mA) VOL (V) 85 °C 25 °C -40 °C 1,8 2 2,2 2,4 2,6 2,8 3 3,2 0 5 10 15 20 IOH (mA) VOH (V)198 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-30. VOH: Output Voltage vs. Source Current I/O Pin, VCC = 5V Figure 21-31. VOL: Output Voltage vs. Sink Current Reset Pin as I/O, VCC = 3V 85 °C 25 °C -40 °C 4,2 4,4 4,6 4,8 5 5,2 0 5 10 15 20 IOH (mA) VOH (V) 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,4 0 0,5 1 1,5 2 2,5 3 IOL (mA) VOL (V)199 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-32. VOL: Output Voltage vs. Sink Current Reset Pin as I/O, VCC = 5V Figure 21-33. VOH: Output Voltage vs. Source Current Reset Pin as I/O, VCC = 3V 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 IOL (mA) VOL (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 IOH (mA) VOH (V)200 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-34. VOH: Output Voltage vs. Source Current Reset Pin as I/O, VCC = 5V 21.2.8 Input Threshold and Hysteresis (for I/O Ports) Figure 21-35. VIH: Input Threshold Voltage vs. VCC I/O Pin, Read as ‘1’ 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 IOH (mA) VOH (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 3,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)201 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-36. VIL: Input Threshold Voltage vs. VCC I/O Pin, Read as ‘0’ Figure 21-37. VIH-VIL: Input Hysteresis vs. VCC I/O Pin 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V)202 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-38. VIH: Input Threshold Voltage vs. VCC Reset Pin as I/O, Read as ‘1’ Figure 21-39. VIL: Input Threshold Voltage vs. VCC Reset Pin as I/O, Read as ‘0’ 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)203 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-40. VIH-VIL: Input Hysteresis vs. VCC Reset Pin as I/O 21.2.9 BOD, Bandgap and Reset Figure 21-41. BOD Threshold vs. Temperature BODLEVEL is 4.3V 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (V) RISING VCC FALLING VCC 4,26 4,28 4,3 4,32 4,34 4,36 4,38 4,4 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (C) Threshold (V)204 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-42. BOD Threshold vs. Temperature BODLEVEL is 2.7V Figure 21-43. BOD Threshold vs. Temperature BODLEVEL is 1.8V 2,68 2,7 2,72 2,74 2,76 2,78 2,8 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (C) Threshold (V) RISING VCC FALLING VCC RISING VCC FALLING VCC 1,77 1,78 1,79 1,8 1,81 1,82 1,83 1,84 1,85 1,86 1,87 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (C) Threshold (V)205 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-44. Bandgap Voltage vs. Supply Voltage Figure 21-45. Bandgap Voltage vs. Temperature 1 1,02 1,04 1,06 1,08 1,1 1,12 1,14 1,16 1,18 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 Vcc (V) Bandgap Voltage (V) 1 1,02 1,04 1,06 1,08 1,1 1,12 1,14 1,16 1,18 1,2 -40 -20 0 20 40 60 80 100 Temperature (C) Bandgap Voltage (V)206 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-46. VIH: Input Threshold Voltage vs. VCC Reset Pin, Read as ‘1’ Figure 21-47. VIL: Input Threshold Voltage vs. VCC Reset Pin, Read as ‘0’ 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)207 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-48. VIH-VIL: Input Hysteresis vs. VCC Reset Pin Figure 21-49. Minimum Reset Pulse Width vs. VCC 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) 85 °C 25 °C -40 °C 0 200 400 600 800 1000 1200 1400 1600 1800 2000 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Pulsewidth (ns)208 8183F–AVR–06/12 ATtiny24A/44A/84A 21.2.10 Analog Comparator Offset Figure 21-50. Analog Comparator Offset VCC = 5V 21.2.11 Internal Oscillator Speed Figure 21-51. Watchdog Oscillator Frequency vs. VCC 85 25 -40 -0.008 -0.006 -0.004 -0.002 0 0.002 0.004 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VIN (V) Offset (V) 85 °C 25 °C -40 °C 112 114 116 118 120 122 124 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) FRC (kHz)209 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-52. Watchdog Oscillator Frequency vs. Temperature Figure 21-53. Calibrated 8 MHz RC Oscillator Frequency vs. VCC 5.5 V 3.0 V 1.8 V 112 114 116 118 120 122 124 -40 -20 0 20 40 60 80 100 Temperature (C) FRC (kHz) 85 °C 25 °C -40 °C 7,4 7,6 7,8 8 8,2 8,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) FRC (MHz)210 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-54. Calibrated 8 MHz RC Oscillator Frequency vs. Temperature Figure 21-55. Calibrated 8 MHz RC Oscillator Frequency vs. OSCCAL Value VCC = 3V 5.5 V 3.0 V 1.8 V 7,5 7,6 7,7 7,8 7,9 8 8,1 8,2 8,3 8,4 -40 -20 0 20 40 60 80 100 Temperature (C) FRC (MHz) 85 °C 25 °C -40 °C 0 4 8 12 16 20 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL (X1) FRC (MHz)211 8183F–AVR–06/12 ATtiny24A/44A/84A 21.3 ATtiny44A 21.3.1 Current Consumption in Active Mode Figure 21-56. Active Supply Current vs. Low Frequency 0.1 - 1.0 MHz, PRR = 0xFF Figure 21-57. Active Supply Current vs. frequency 1 - 20 MHz, PRR = 0xFF 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 2 4 6 8 10 12 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA)212 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-58. Active Supply Current vs. VCC Internal RC Oscillator, 8 MHz Figure 21-59. Active Supply Current vs. VCC Internal RC Oscillator, 1 MHz 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA)213 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-60. Active Supply Current vs. VCC Internal RC Oscillator, 128 kHz 21.3.2 Current Consumption in Idle Mode Figure 21-61. Idle Supply Current vs. Low Frequency 0.1 - 1.0 MHz, PRR = 0xFF 85 °C 25 °C -40 °C 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)214 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-62. Idle Supply Current vs. Frequency 1 - 20 MHz, PRR = 0xFF Figure 21-63. Idle Supply Current vs. VCC Internal RC Oscillator, 8 MHz 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.5 1 1.5 2 2.5 3 3.5 4 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA)215 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-64. Idle Supply Current vs. VCC Internal RC Oscillator, 1 MHz Figure 21-65. Idle Supply Current vs. VCC Internal RC Oscillator, 128 kHz 85 °C 25 °C -40 °C 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0.005 0.01 0.015 0.02 0.025 0.03 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA)216 8183F–AVR–06/12 ATtiny24A/44A/84A 21.3.3 Standby Supply Current Figure 21-66. Standby Supply Current vs. VCC 4 MHz External Crystal, 22 pF External Capacitors, Watchdog Timer Disabled 21.3.4 Current Consumption in Power-down Mode Figure 21-67. Power-down Supply Current vs. VCC Watchdog Timer Disabled 85 °C 25 °C -40 °C 0 0.02 0.04 0.06 0.08 0.1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (uA)217 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-68. Power-down Supply Current vs. VCC Watchdog Timer Enabled 21.3.5 Current Consumption in Reset Figure 21-69. Reset Supply Current vs. VCC 0.1 - 1.0 MHz, Excluding Current through Reset Pull-up 85 °C 25 °C -40 °C 0 2 4 6 8 10 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (uA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)218 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-70. Reset Supply Current vs. VCC 1 - 20 MHz, Excluding Current Through Reset Pull-up 21.3.6 Current Consumption of Peripheral Units Figure 21-71. ADC Current vs. VCC 4 MHz Frequency 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0.5 1 1.5 2 2.5 3 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 0 100 200 300 400 500 600 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (uA)219 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-72. AREF Pin Current vs. Pin Voltage Figure 21-73. Analog Comparator Current vs. VCC 4 MHz Frequency 0 20 40 60 80 100 120 140 160 180 1.5 2 2.5 3 3.5 4 4.5 5 5.5 AREF (V) AREF pin current (uA) 0 20 40 60 80 100 120 140 160 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (uA)220 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-74. Programming Current vs. VCC Figure 21-75. Brownout Detector Current vs. VCC BOD Level = 1.8V 85 °C 25 °C -40 °C 0 2000 4000 6000 8000 10000 12000 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (uA) 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (uA)221 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-76. Watchdog Timer Current vs. VCC 21.3.7 Pull-up Resistors Figure 21-77. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 1.8V 85 °C 25 °C -40 °C 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) ICC (mA) 85 °C 25 °C -40 °C 0 10 20 30 40 50 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOP (V) IOP (uA)222 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-78. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 2.7V Figure 21-79. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 5V 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 70 80 0 0.5 1 1.5 2 2.5 3 VOP (V) IOP (uA) 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 140 160 012345 VOP (V) IOP (uA)223 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-80. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 1.8V Figure 21-81. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 2.7V 0 5 10 15 20 25 30 35 40 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C 85 °C 25 °C 0 -40 °C 10 20 30 40 50 60 0 0.5 1 1.5 2 2.5 3 VRESET (V) IRESET (uA)224 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-82. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 5V 21.3.8 Output Driver Strength Figure 21-83. VOL: Output Voltage vs. Sink Current I/O Pin, VCC = 3V 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 012345 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 0 5 10 15 20 IOL (mA) VOL (V)225 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-84. VOL: Output Voltage vs. Sink Current I/O Pin, VCC = 5V Figure 21-85. VOH: Output Voltage vs. Source Current I/O Pin, VCC = 3V 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 5 10 15 20 IOL (mA) VOL (V) 85 °C 25 °C -40 °C 1.8 2 2.2 2.4 2.6 2.8 3 3.2 0 5 10 15 20 IOH (mA) VOH (V)226 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-86. VOH: Output Voltage vs. Source Current I/O Pin, VCC = 5V Figure 21-87. VOL: Output Voltage vs. Sink Current Reset Pin as I/O, VCC = 3V 85 °C 25 °C -40 °C 4.2 4.4 4.6 4.8 5 5.2 0 5 10 15 20 IOH (mA) VOH (V) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0 0.5 1 1.5 2 2.5 3 IOL (mA) VOL (V)227 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-88. VOL: Output Voltage vs. Sink Current Reset Pin as I/O, VCC = 5V Figure 21-89. VOH: Output Voltage vs. Source Current Reset Pin as I/O, VCC = 3V 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 012345678 IOL (mA) VOL (V) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 IOH (mA) VOH (V)228 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-90. VOH: Output Voltage vs. Source Current Reset Pin as I/O, VCC = 5V 21.3.9 Input Threshold and Hysteresis (for I/O Ports) Figure 21-91. VIH: Input Threshold Voltage vs. VCC IO Pin, Read as ‘1’ 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 IOH (mA) VOH (V) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 3.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Threshold (V)229 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-92. VIL: Input Threshold Voltage vs. VCC I/O Pin, Read as ‘0’ Figure 21-93. VIH-VIL: Input Hysteresis vs. VCC I/O Pin 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Input Hysteresis (V)230 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-94. VIH: Input Threshold Voltage vs. VCC Reset Pin as I/O, Read as ‘1’ Figure 21-95. VIL: Input Threshold Voltage vs. VCC Reset Pin as I/O, Read as ‘0’ 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Threshold (V)231 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-96. VIH-VIL: Input Hysteresis vs. VCC Reset Pin as I/O 21.3.10 BOD, Bandgap and Reset Figure 21-97. BOD Threshold vs. Temperature BODLEVEL is 4.3V 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Input Hysteresis (V) 4.2 4.22 4.24 4.26 4.28 4.3 4.32 4.34 4.36 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) RISING VCC FALLING VCC232 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-98. BOD Threshold vs. Temperature BODLEVEL is 2.7V Figure 21-99. BOD Threshold vs. Temperature BODLEVEL is 1.8V 2.64 2.66 2.68 2.7 2.72 2.74 2.76 2.78 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) RISING VCC FALLING VCC RISING VCC FALLING VCC 1.77 1.78 1.79 1.8 1.81 1.82 1.83 1.84 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V)233 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-100. Bandgap Voltage vs. Supply Voltage Figure 21-101. Bandgap Voltage vs. Temperature 1 1.02 1.04 1.06 1.08 1.1 1.12 1.14 1.16 1.18 1.2 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Bandgap Voltage (V) 1 1.02 1.04 1.06 1.08 1.1 1.12 1.14 1.16 1.18 1.2 -40 -20 0 20 40 60 80 100 Temperature (C) Bandgap Voltage (V)234 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-102. VIH: Input Threshold Voltage vs. VCC Reset Pin, Read as ‘1’ Figure 21-103. VIL: Input Threshold Voltage vs. VCC Reset Pin, Read as ‘0’ 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V)235 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-104. VIH-VIL: Input Hysteresis vs. VCC Reset Pin Figure 21-105. Minimum Reset Pulse Width vs. VCC 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Input Hysteresis (V) 85 °C 25 °C -40 °C 0 200 400 600 800 1000 1200 1400 1600 1800 2000 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Pulsewidth (ns)236 8183F–AVR–06/12 ATtiny24A/44A/84A 21.3.11 Analog Comparator Offset Figure 21-106. Analog Comparator Offset VCC = 5V 21.3.12 Internal Oscillator Speed Figure 21-107. Watchdog Oscillator Frequency vs. VCC 85 25 -40 -0.007 -0.006 -0.005 -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003 0.004 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VIN (V) Offset (V) 85 °C 25 °C -40 °C 0.108 0.11 0.112 0.114 0.116 0.118 0.12 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Frequency (MHz)237 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-108. Watchdog Oscillator Frequency vs. Temperature Figure 21-109. Calibrated 8 MHz RC Oscillator Frequency vs. VCC 5.5 V 3.0 V 1.8 V 0.106 0.108 0.11 0.112 0.114 0.116 0.118 0.12 -40 -20 0 20 40 60 80 100 Temperature (C) Frequency (MHz) 7.4 7.6 7.8 8 8.2 8.4 1.5 2 2.5 3 3.5 4 4.5 5 5.5 V CC (V) Frequency (MHz) 85 °C 25 °C -40 °C238 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-110. Calibrated 8 MHz RC oscillator Frequency vs. Temperature Figure 21-111. Calibrated 8 MHz RC Oscillator Frequency vs. OSCCAL Value VCC = 3V 5.0 V 3.0 V 1.8 V 7.5 7.6 7.7 7.8 7.9 8 8.1 8.2 -40 -20 0 20 40 60 80 100 Temperature (C) Frequency (MHz) 85 °C 25 °C -40 °C 0 2 4 6 8 10 12 14 16 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL (X1) Frequency (MHz)239 8183F–AVR–06/12 ATtiny24A/44A/84A 21.4 ATtiny84A 21.4.1 Current Consumption in Active Mode Figure 21-112. Active Supply Current vs. Low Frequency 0.1 - 1.0 MHz, PRR = 0xFF Figure 21-113. Active Supply Current vs. Frequency 1 - 20 MHz, PRR = 0xFF 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,2 0,4 0,6 0,8 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 2 4 6 8 10 12 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA)240 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-114. Active Supply Current vs. VCC Internal RC Oscillator, 8 MHz Figure 21-115. Active Supply Current vs. VCC Internal RC Oscillator, 1 MHz 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA)241 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-116. Active Supply Current vs. VCC Internal RC Oscillator, 128 kHz 21.4.2 Current Consumption in Idle Mode Figure 21-117. Idle Supply Current vs. Low Frequency 0.1 - 1.0 MHz, PRR = 0xFF 85 °C 25 °C -40 °C 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA)242 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-118. Idle Supply Current vs. Frequency 1 - 20 MHz, PRR = 0xFF Figure 21-119. Idle Supply Current vs. VCC Internal RC Oscillator, 8 MHz 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,5 1 1,5 2 2,5 3 3,5 4 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C243 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-120. Idle Supply Current vs. VCC Internal RC Oscillator, 1 MHz Figure 21-121. Idle Supply Current vs. VCC Internal RC Oscillator, 128 kHz 85 °C 25 °C -40 °C 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 0 0,005 0,01 0,015 0,02 0,025 0,03 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C244 8183F–AVR–06/12 ATtiny24A/44A/84A 21.4.3 Current Consumption in Power-down Mode Figure 21-122. Power-down Supply Current vs. VCC Watchdog Timer Disabled Figure 21-123. Power-down Supply Current vs. VCC Watchdog Timer Enabled 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 2 4 6 8 10 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C245 8183F–AVR–06/12 ATtiny24A/44A/84A 21.4.4 Current Consumption in Reset Figure 21-124. Reset Supply Current vs. VCC 0.1 - 1.0 MHz, Excluding Current through Reset Pull-up Figure 21-125. Reset Supply Current vs. VCC 1 - 20 MHz, Excluding Current through Reset Pull-up 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0,16 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.3 V 2.7 V 1.8 V 0 0,5 1 1,5 2 2,5 3 0 2 4 6 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA)246 8183F–AVR–06/12 ATtiny24A/44A/84A 21.4.5 Current Consumption of Peripheral Units Figure 21-126. ADC Current vs. VCC 4 MHz Frequency Figure 21-127. AREF Pin Current vs. Pin Voltage 0 100 200 300 400 500 600 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 0 20 40 60 80 100 120 140 160 1,5 2 2,5 3 3,5 4 4,5 5 5,5 AREF (V) AREF pin current (uA)247 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-128. Analog Comparator Current vs. VCC 4 MHz Frequency Figure 21-129. Programming Current vs. VCC 0 20 40 60 80 100 120 140 160 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 1000 2000 3000 4000 5000 6000 7000 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA)248 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-130. Brownout Detector Current vs. VCC BOD Level = 1.8V 21.4.6 Pull-up Resistors Figure 21-131. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 1.8V 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 40 45 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VOP (V) IOP (uA)249 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-132. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 2.7V Figure 21-133. Pull-up Resistor Current vs. Input Voltage I/O Pin, VCC = 5V 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 70 80 0 0,5 1 1,5 2 2,5 3 VOP (V) IOP (uA) 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 140 160 0 1 2 3 4 5 6 VOP (V) IOP (uA)250 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-134. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 1.8V Figure 21-135. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 2.7V 85 °C 25 °C -40 °C 0 5 10 15 20 25 30 35 40 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 0 0,5 1 1,5 2 2,5 3 VRESET (V) IRESET (uA)251 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-136. Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 5V 21.4.7 Output Driver Strength Figure 21-137. VOL: Output Voltage vs. Sink Current I/O Pin, VCC = 3V 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 0 2 4 6 8 10 12 14 16 18 20 IOL (mA) VOL (V)252 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-138. VOL: Output Voltage vs. Sink Current I/O Pin, VCC = 5V Figure 21-139. VOH: Output Voltage vs. Source Current I/O Pin, VCC = 3V 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0 2 4 6 8 10 12 14 16 18 20 IOL (mA) VOL (V) 85 °C 25 °C -40 °C 1,8 2 2,2 2,4 2,6 2,8 3 3,2 0 2 4 6 8 10 12 14 16 18 20 IOH (mA) VOH (V)253 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-140. VOH: Output Voltage vs. Source Current I/O Pin, VCC = 5V Figure 21-141. VOL: Output Voltage vs. Sink Current Reset Pin as I/O, VCC = 3V 85 °C 25 °C -40 °C 4,2 4,4 4,6 4,8 5 5,2 0 2 4 6 8 10 12 14 16 18 20 IOH (mA) VOH (V) 0 0,2 0,4 0,6 0,8 1 1,2 1,4 0 0,5 1 1,5 2 2,5 3 IOL (mA) VOL (V) 85 °C 25 °C -40 °C254 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-142. VOL: Output Voltage vs. Sink Current Reset Pin as I/O, VCC = 5V Figure 21-143. VOH: Output Voltage vs. Source Current Reset Pin as I/O, VCC = 3V 85 °C 25 °C -40 °C 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 012345678 IOL (mA) VOL (V) 0 0,5 1 1,5 2 2,5 3 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 IOH (mA) VOH (V) 85 °C 25 °C -40 °C255 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-144. VOH: Output Voltage vs. Source Current Reset Pin as I/O, VCC = 5V 21.4.8 Input Threshold and Hysteresis (for I/O Ports) Figure 21-145. VIH: Input Threshold Voltage vs. VCC I/O Pin, Read as ‘1’ 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 IOH (mA) VOH (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 3 3,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C256 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-146. VIL: Input Threshold Voltage vs. VCC I/O Pin, Read as ‘0’ Figure 21-147. VIH-VIL: Input Hysteresis vs. VCC I/O Pin 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 0 0,1 0,2 0,3 0,4 0,5 0,6 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) 85 °C 25 °C -40 °C257 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-148. VIH: Input Threshold Voltage vs. VCC Reset Pin as I/O, Read as ‘1’ Figure 21-149. VIL: Input Threshold Voltage vs. VCC Reset Pin as I/O, Read as ‘0’ 0 0,5 1 1,5 2 2,5 3 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C258 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-150. VIH-VIL: Input Hysteresis vs. VCC Reset Pin as I/O 21.4.9 BOD, Bandgap and Reset Figure 21-151. BOD Threshold vs. Temperature BODLEVEL is 4.3V 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) 4,24 4,26 4,28 4,3 4,32 4,34 4,36 4,38 4,4 4,42 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) RISING VCC FALLING VCC259 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-152. BOD Threshold vs. Temperature BODLEVEL is 2.7V Figure 21-153. Bandgap Voltage vs. Supply Voltage 2,66 2,68 2,7 2,72 2,74 2,76 2,78 2,8 2,82 -40 -20 0 20 40 60 80 100 Temperature (C) Threshold (V) RISING VCC FALLING VCC 1 1,02 1,04 1,06 1,08 1,1 1,12 1,14 1,16 1,18 1,2 1,5 2 2,5 3 3,5 4 4,5 5 5,5 Vcc (V) Bandgap Voltage (V)260 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-154. Bandgap Voltage vs. Temperature Figure 21-155. VIH: Input Threshold Voltage vs. VCC Reset Pin, Read as ‘1’ 1 1,02 1,04 1,06 1,08 1,1 1,12 1,14 1,16 1,18 1,2 -40 -20 0 20 40 60 80 100 Temperature (C) Bandgap Voltage (V) 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C261 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-156. VIL: Input Threshold Voltage vs. VCC Reset Pin, Read as ‘0’ Figure 21-157. VIH-VIL: Input Hysteresis vs. VCC Reset Pin 0 0,5 1 1,5 2 2,5 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Threshold (V) 85 °C 25 °C -40 °C 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Input Hysteresis (V) 85 °C 25 °C -40 °C262 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-158. Minimum Reset Pulse Width vs. VCC 21.4.10 Analog Comparator Offset Figure 21-159. Analog Comparator Offset VCC = 5V 0 200 400 600 800 1000 1200 1400 1600 1800 2000 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) Pulsewidth (ns) 85 °C 25 °C -40 °C 85 25 -40 -0.012 -0.01 -0.008 -0.006 -0.004 -0.002 0 0.002 0.004 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Vin (V) Offset (V)263 8183F–AVR–06/12 ATtiny24A/44A/84A 21.4.11 Internal Oscillator Speed Figure 21-160. Watchdog Oscillator Frequency vs. VCC Figure 21-161. Watchdog Oscillator Frequency vs. Temperature 108 110 112 114 116 118 120 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) FRC (kHz) 85 °C 25 °C -40 °C 5.5 V 3.0 V 1.8 V 106 108 110 112 114 116 118 120 -40 -20 0 20 40 60 80 100 Temperature (C) FRC (kHz)264 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-162. Calibrated 8 MHz RC Oscillator Frequency vs. VCC Figure 21-163. Calibrated 8 MHz RC Oscillator Frequency vs. Temperature 7,4 7,5 7,6 7,7 7,8 7,9 8 8,1 8,2 8,3 8,4 1,5 2 2,5 3 3,5 4 4,5 5 5,5 VCC (V) FRC (MHz) 85 °C 25 °C -40 °C 5.0 V 3.0 V 1.8 V 7,5 7,6 7,7 7,8 7,9 8 8,1 8,2 8,3 8,4 -40 -20 0 20 40 60 80 100 Temperature (C) FRC (MHz)265 8183F–AVR–06/12 ATtiny24A/44A/84A Figure 21-164. Calibrated 8 MHz RC Oscillator Frequency vs. OSCCAL Value VCC = 3V 0 2 4 6 8 10 12 14 16 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL (X1) FRC (MHz) 85 °C 25 °C -40 °C266 8183F–AVR–06/12 ATtiny24A/44A/84A 22. Register Summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page 0x3F (0x5F) SREG I T H S V N Z C Page 14 0x3E (0x5E) SPH – – – – – – SP9 SP8 Page 13 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 Page 13 0x3C (0x5C) OCR0B Timer/Counter0 – Output Compare Register B Page 83 0x3B (0x5B) GIMSK – INT0 PCIE1 PCIE0 – – – – Page 50 0x3A (0x5A) GIFR – INTF0 PCIF1 PCIF0 – – – – Page 51 0x39 (0x59) TIMSK0 – – – – – OCIE0B OCIE0A TOIE0 Page 83 0x38 (0x58) TIFR0 – – – – – OCF0B OCF0A TOV0 Page 84 0x37 (0x57) SPMCSR – – RSIG CTPB RFLB PGWRT PGERS SPMEN Page 156 0x36 (0x56) OCR0A Timer/Counter0 – Output Compare Register A Page 83 0x35 (0x55) MCUCR BODS PUD SE SM1 SM0 BODSE ISC01 ISC00 Pages 36, 50, 66 0x34 (0x54) MCUSR – – – – WDRF BORF EXTRF PORF Page 44 0x33 (0x53) TCCR0B FOC0A FOC0B – – WGM02 CS02 CS01 CS00 Page 82 0x32 (0x52) TCNT0 Timer/Counter0 Page 83 0x31 (0x51) OSCCAL CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0 Page 31 0x30 (0x50) TCCR0A COM0A1 COM0A0 COM0B1 COM0B0 – – WGM01 WGM00 Page 79 0x2F (0x4F) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 – – WGM11 WGM10 Page 106 0x2E (0x4E) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 Page 108 0x2D (0x4D) TCNT1H Timer/Counter1 – Counter Register High Byte Page 110 0x2C (0x4C) TCNT1L Timer/Counter1 – Counter Register Low Byte Page 110 0x2B (0x4B) OCR1AH Timer/Counter1 – Compare Register A High Byte Page 110 0x2A (0x4A) OCR1AL Timer/Counter1 – Compare Register A Low Byte Page 110 0x29 (0x49) OCR1BH Timer/Counter1 – Compare Register B High Byte Page 110 0x28 (0x48) OCR1BL Timer/Counter1 – Compare Register B Low Byte Page 110 0x27 (0x47) DWDR DWDR[7:0] Page 151 0x26 (0x46) CLKPR CLKPCE – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 Page 31 0x25 (0x45) ICR1H Timer/Counter1 - Input Capture Register High Byte Page 111 0x24 (0x44) ICR1L Timer/Counter1 - Input Capture Register Low Byte Page 111 0x23 (0x43) GTCCR TSM – – – – – – PSR10 Page 114 0x22 (0x42) TCCR1C FOC1A FOC1B – – – – – – Page 109 0x21 (0x41) WDTCSR WDIF WDIE WDP3 WDCE WDE WDP2 WDP1 WDP0 Page 44 0x20 (0x40) PCMSK1 – – – – PCINT11 PCINT10 PCINT9 PCINT8 Page 51 0x1F (0x3F) EEARH – – – – – – – EEAR8 Page 20 0x1E (0x3E) EEARL EEAR7 EEAR6 EEAR5 EEAR4 EEAR3 EEAR2 EEAR1 EEAR0 Page 21 0x1D (0x3D) EEDR EEPROM Data Register Page 21 0x1C (0x3C) EECR – – EEPM1 EEPM0 EERIE EEMPE EEPE EERE Page 23 0x1B (0x3B) PORTA PORTA7 PORTA6 PORTA5 PORTA4 PORTA3 PORTA2 PORTA1 PORTA0 Page 66 0x1A (0x3A) DDRA DDA7 DDA6 DDA5 DDA4 DDA3 DDA2 DDA1 DDA0 Page 66 0x19 (0x39) PINA PINA7 PINA6 PINA5 PINA4 PINA3 PINA2 PINA1 PINA0 Page 67 0x18 (0x38) PORTB – – – – PORTB3 PORTB2 PORTB1 PORTB0 Page 67 0x17 (0x37) DDRB – – – – DDB3 DDB2 DDB1 DDB0 Page 67 0x16 (0x36) PINB – – – – PINB3 PINB2 PINB1 PINB0 Page 67 0x15 (0x35) GPIOR2 General Purpose I/O Register 2 Page 22 0x14 (0x34) GPIOR1 General Purpose I/O Register 1 Page 23 0x13 (0x33) GPIOR0 General Purpose I/O Register 0 Page 23 0x12 (0x32) PCMSK0 PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 Page 52 0x11 (0x31)) Reserved – 0x10 (0x30) USIBR USI Buffer Register Page 127 0x0F (0x2F) USIDR USI Data Register Page 126 0x0E (0x2E) USISR USISIF USIOIF USIPF USIDC USICNT3 USICNT2 USICNT1 USICNT0 Page 125 0x0D (0x2D) USICR USISIE USIOIE USIWM1 USIWM0 USICS1 USICS0 USICLK USITC Page 123 0x0C (0x2C) TIMSK1 – – ICIE1 – – OCIE1B OCIE1A TOIE1 Page 111 0x0B (0x2B) TIFR1 – – ICF1 – – OCF1B OCF1A TOV1 Page 112 0x0A (0x2A) Reserved – 0x09 (0x29) Reserved – 0x08 (0x28) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 Page 129 0x07 (0x27) ADMUX REFS1 REFS0 MUX5 MUX4 MUX3 MUX2 MUX1 MUX0 Page 144 0x06 (0x26) ADCSRA ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 Page 146 0x05 (0x25) ADCH ADC Data Register High Byte Page 148 0x04 (0x24) ADCL ADC Data Register Low Byte Page 148 0x03 (0x23) ADCSRB BIN ACME – ADLAR – ADTS2 ADTS1 ADTS0 Pages 130, 148 0x02 (0x22) Reserved – 0x01 (0x21) DIDR0 ADC7D ADC6D ADC5D ADC4D ADC3D ADC2D ADC1D ADC0D Pages 131, 149 0x00 (0x20) PRR – – – – PRTIM1 PRTIM0 PRUSI PRADC Page 37267 8183F–AVR–06/12 ATtiny24A/44A/84A Note: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operation the specified bit, and can therefore be used on registers containing such Status Flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only.268 8183F–AVR–06/12 ATtiny24A/44A/84A 23. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd ← Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd ← Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl ← Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd ← Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd ← Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd ← Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd ← Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl ← Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd ← Rd • Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd ← Rd • K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd ← Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd ← Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd ← Rd ⊕ Rr Z,N,V 1 COM Rd One’s Complement Rd ← 0xFF − Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd ← 0x00 − Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd ← Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd ← Rd • (0xFF - K) Z,N,V 1 INC Rd Increment Rd ← Rd + 1 Z,N,V 1 DEC Rd Decrement Rd ← Rd − 1 Z,N,V 1 TST Rd Test for Zero or Minus Rd ← Rd • Rd Z,N,V 1 CLR Rd Clear Register Rd ← Rd ⊕ Rd Z,N,V 1 SER Rd Set Register Rd ← 0xFF None 1 BRANCH INSTRUCTIONS RJMP k Relative Jump PC ← PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC ← Z None 2 RCALL k Relative Subroutine Call PC ← PC + k + 1 None 3 ICALL Indirect Call to (Z) PC ← Z None 3 RET Subroutine Return PC ← STACK None 4 RETI Interrupt Return PC ← STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC ← PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd − Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd − Rr − C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd − K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC ← PC + 2 or 3 None 1/2/3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC ← PC + 2 or 3 None 1/2/3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PC←PC+k + 1 None 1/2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PC←PC+k + 1 None 1/2 BREQ k Branch if Equal if (Z = 1) then PC ← PC + k + 1 None 1/2 BRNE k Branch if Not Equal if (Z = 0) then PC ← PC + k + 1 None 1/2 BRCS k Branch if Carry Set if (C = 1) then PC ← PC + k + 1 None 1/2 BRCC k Branch if Carry Cleared if (C = 0) then PC ← PC + k + 1 None 1/2 BRSH k Branch if Same or Higher if (C = 0) then PC ← PC + k + 1 None 1/2 BRLO k Branch if Lower if (C = 1) then PC ← PC + k + 1 None 1/2 BRMI k Branch if Minus if (N = 1) then PC ← PC + k + 1 None 1/2 BRPL k Branch if Plus if (N = 0) then PC ← PC + k + 1 None 1/2 BRGE k Branch if Greater or Equal, Signed if (N ⊕ V= 0) then PC ← PC + k + 1 None 1/2 BRLT k Branch if Less Than Zero, Signed if (N ⊕ V= 1) then PC ← PC + k + 1 None 1/2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC ← PC + k + 1 None 1/2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC ← PC + k + 1 None 1/2 BRTS k Branch if T Flag Set if (T = 1) then PC ← PC + k + 1 None 1/2 BRTC k Branch if T Flag Cleared if (T = 0) then PC ← PC + k + 1 None 1/2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC ← PC + k + 1 None 1/2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC ← PC + k + 1 None 1/2 BRIE k Branch if Interrupt Enabled if ( I = 1) then PC ← PC + k + 1 None 1/2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC ← PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b) ← 1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b) ← 0 None 2 LSL Rd Logical Shift Left Rd(n+1) ← Rd(n), Rd(0) ← 0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n) ← Rd(n+1), Rd(7) ← 0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)←C,Rd(n+1)← Rd(n),C←Rd(7) Z,C,N,V 1269 8183F–AVR–06/12 ATtiny24A/44A/84A ROR Rd Rotate Right Through Carry Rd(7)←C,Rd(n)← Rd(n+1),C←Rd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n) ← Rd(n+1), n=0..6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3..0)←Rd(7..4),Rd(7..4)←Rd(3..0) None 1 BSET s Flag Set SREG(s) ← 1 SREG(s) 1 BCLR s Flag Clear SREG(s) ← 0 SREG(s) 1 BST Rr, b Bit Store from Register to T T ← Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b) ← T None 1 SEC Set Carry C ← 1 C1 CLC Clear Carry C ← 0 C 1 SEN Set Negative Flag N ← 1 N1 CLN Clear Negative Flag N ← 0 N 1 SEZ Set Zero Flag Z ← 1 Z1 CLZ Clear Zero Flag Z ← 0 Z 1 SEI Global Interrupt Enable I ← 1 I1 CLI Global Interrupt Disable I ← 0 I 1 SES Set Signed Test Flag S ← 1 S1 CLS Clear Signed Test Flag S ← 0 S 1 SEV Set Twos Complement Overflow. V ← 1 V1 CLV Clear Twos Complement Overflow V ← 0 V 1 SET Set T in SREG T ← 1 T1 CLT Clear T in SREG T ← 0 T 1 SEH Set Half Carry Flag in SREG H ← 1 H1 CLH Clear Half Carry Flag in SREG H ← 0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd ← Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd ← Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd ← K None 1 LD Rd, X Load Indirect Rd ← (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd ← (X), X ← X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X ← X - 1, Rd ← (X) None 2 LD Rd, Y Load Indirect Rd ← (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd ← (Y), Y ← Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y ← Y - 1, Rd ← (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd ← (Y + q) None 2 LD Rd, Z Load Indirect Rd ← (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd ← (Z), Z ← Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z ← Z - 1, Rd ← (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd ← (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd ← (k) None 2 ST X, Rr Store Indirect (X) ← Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) ← Rr, X ← X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X ← X - 1, (X) ← Rr None 2 ST Y, Rr Store Indirect (Y) ← Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y) ← Rr, Y ← Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y ← Y - 1, (Y) ← Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q) ← Rr None 2 ST Z, Rr Store Indirect (Z) ← Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z) ← Rr, Z ← Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z ← Z - 1, (Z) ← Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q) ← Rr None 2 STS k, Rr Store Direct to SRAM (k) ← Rr None 2 LPM Load Program Memory R0 ← (Z) None 3 LPM Rd, Z Load Program Memory Rd ← (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd ← (Z), Z ← Z+1 None 3 SPM Store Program Memory (z) ← R1:R0 None IN Rd, P In Port Rd ← P None 1 OUT P, Rr Out Port P ← Rr None 1 PUSH Rr Push Register on Stack STACK ← Rr None 2 POP Rd Pop Register from Stack Rd ← STACK None 2 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/Timer) None 1 BREAK Break For On-chip Debug Only None N/A Mnemonics Operands Description Operation Flags #Clocks270 8183F–AVR–06/12 ATtiny24A/44A/84A 24. Ordering Information Notes: 1. For speed vs. supply voltage, see section 20.3 “Speed” on page 174. 2. All packages are Pb-free, halide-free and fully green and they comply with the European directive for Restriction of Hazardous Substances (RoHS) 3. Code indicators: – H: NiPdAu lead finish – F, N, U: matte tin – R: tape & reel 4. Topside marking for ATtiny24A: T24 / Axx / manufacturing data 5. Also supplied in wafer form. Contact your local Atmel sales office for ordering information and minimum quantities. 6. For typical and electrical characteristics, see “Appendix A – ATtiny24A/44A Specification at 105°C”. 7. For typical and electrical characteristics, see “Appendix B – ATtiny24A/44A/84A Specification at 125°C”. 24.1 ATtiny24A Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 20 1.8 – 5.5V Industrial (-40°C to +85°C) (5) 14S1 ATtiny24A-SSU ATtiny24A-SSUR 14P3 ATtiny24A-PU 15CC1 ATtiny24A-CCU ATtiny24A-CCUR 20M1 ATtiny24A-MU ATtiny24A-MUR 20M2 ATtiny24A-MMH (4) ATtiny24A-MMHR (4) Industrial (-40°C to +105°C) (6) 14S1 ATtiny24A-SSN ATtiny24A-SSNR Industrial (-40°C to +125°C) (7) 14S1 ATtiny24A-SSF ATtiny24A-SSFR 20M1 ATtiny24A-MF ATtiny24A-MFR 20M2 ATtiny24A-MM8 ATtiny24A-MM8R Package Type 14S1 14-lead, 0.150" Wide Body, Plastic Gull Wing Small Outline Package (SOIC) 14P3 14-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 15CC1 15-ball (4 x 4 Array), 0.65 mm Pitch, 3.0 x 3.0 x 0.6 mm, Ultra Thin, Fine-Pitch Ball Grid Array Package (UFBGA) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No Lead / Micro Lead Frame Package (QFN/MLF) 20M2 20-pad, 3 x 3 x 0.85 mm Body, Very Thin Quad Flat No Lead Package (VQFN)271 8183F–AVR–06/12 ATtiny24A/44A/84A Notes: 1. For speed vs. supply voltage, see section 20.3 “Speed” on page 174. 2. All packages are Pb-free, halide-free and fully green and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: – H: NiPdAu lead finish – F, N, U: matte tin – R: tape & reel 4. Topside marking for ATtiny44A: – 1st Line: T44 – 2nd Line: Axx – 3rd Line: manufacturing data 5. These devices can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 6. For typical and electrical characteristics, see “Appendix A – ATtiny24A/44A Specification at 105°C”. 7. For typical and electrical characteristics, see “Appendix B – ATtiny24A/44A/84A Specification at 125°C”. 24.2 ATtiny44A Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 20 1.8 – 5.5V Industrial (-40°C to +85°C) (5) 14S1 ATtiny44A-SSU ATtiny44A-SSUR 14P3 ATtiny44A-PU 15CC1 ATtiny44A-CCU ATtiny44A-CCUR 20M1 ATtiny44A-MU ATtiny44A-MUR 20M2 ATtiny44A-MMH (4) ATtiny44A-MMHR (4) Industrial (-40°C to +105°C) (6) 14S1 ATtiny44A-SSN ATtiny44A-SSNR Industrial (-40°C to +125°C) (7) 14S1 ATtiny44A-SSF ATtiny44A-SSFR 20M1 ATtiny44A-MF ATtiny44A-MFR Package Type 14S1 14-lead, 0.150" Wide Body, Plastic Gull Wing Small Outline Package (SOIC) 14P3 14-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 15CC1 15-ball (4 x 4 Array), 0.65 mm Pitch, 3.0 x 3.0 x 0.6 mm, Ultra Thin, Fine-Pitch Ball Grid Array Package (UFBGA) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No Lead / Micro Lead Frame Package (QFN/MLF) 20M2 20-pad, 3 x 3 x 0.85 mm Body, Very Thin Quad Flat No Lead Package (VQFN)272 8183F–AVR–06/12 ATtiny24A/44A/84A Notes: 1. For speed vs. supply voltage, see section 20.3 “Speed” on page 174. 2. All packages are Pb-free, halide-free and fully green and they comply with the European directive for Restriction of Hazardous Substances (RoHS). 3. Code indicators: – H: NiPdAu lead finish – F, N, U: matte tin – R: tape & reel 4. Topside marking for ATtiny84A: – 1st Line: T84 – 2nd Line: Axx – 3rd Line: manufacturing data 5. These devices can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 6. For typical and electrical characteristics, see “Appendix A – ATtiny24A/44A Specification at 105°C”. 7. For typical and electrical characteristics, see “Appendix B – ATtiny24A/44A/84A Specification at 125°C”. 24.3 ATtiny84A Speed (MHz) (1) Supply Voltage (V) Temperature Range Package (2) Ordering Code (3) 20 1.8 – 5.5V Industrial (-40°C to +85°C) (5) 14S1 ATtiny84A-SSU ATtiny84A-SSUR 14P3 ATtiny84A-PU 15CC1 ATtiny84A-CCU ATtiny84A-CCUR 20M1 ATtiny84A-MU ATtiny84A-MUR 20M2 ATtiny84A-MMH (4) ATtiny84A-MMHR (4) Industrial (-40°C to +125°C) (7) 14S1 ATtiny84A-SSF ATtiny84A-SSFR Package Type 14S1 14-lead, 0.150" Wide Body, Plastic Gull Wing Small Outline Package (SOIC) 14P3 14-lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 15CC1 15-ball (4 x 4 Array), 0.65 mm Pitch, 3.0 x 3.0 x 0.6 mm, Ultra Thin, Fine-Pitch Ball Grid Array Package (UFBGA) 20M1 20-pad, 4 x 4 x 0.8 mm Body, Quad Flat No Lead / Micro Lead Frame Package (QFN/MLF) 20M2 20-pad, 3 x 3 x 0.85 mm Body, Very Thin Quad Flat No Lead Package (VQFN)273 8183F–AVR–06/12 ATtiny24A/44A/84A 25. Packaging Information 25.1 14S1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 14S1, 14-lead, 0.150" Wide Body, Plastic Gull Wing Small Outline Package (SOIC) 2/5/02 14S1 A A1 E L Side View Top View End View E H b N 1 e A D COMMON DIMENSIONS (Unit of Measure = mm/inches) SYMBOL MIN NOM MAX NOTE Notes: 1. This drawing is for general information only; refer to JEDEC Drawing MS-012, Variation AB for additional information. 2. Dimension D does not include mold Flash, protrusions or gate burrs. Mold Flash, protrusion and gate burrs shall not exceed 0.15 mm (0.006") per side. 3. Dimension E does not include inter-lead Flash or protrusion. Inter-lead flash and protrusions shall not exceed 0.25 mm (0.010") per side. 4. L is the length of the terminal for soldering to a substrate. 5. The lead width B, as measured 0.36 mm (0.014") or greater above the seating plane, shall not exceed a maximum value of 0.61 mm (0.024") per side. A 1.35/0.0532 – 1.75/0.0688 A1 0.1/.0040 – 0.25/0.0098 b 0.33/0.0130 – 0.5/0.02005 D 8.55/0.3367 – 8.74/0.3444 2 E 3.8/0.1497 – 3.99/0.1574 3 H 5.8/0.2284 – 6.19/0.2440 L 0.41/0.0160 – 1.27/0.0500 4 e 1.27/0.050 BSC274 8183F–AVR–06/12 ATtiny24A/44A/84A 25.2 14P3 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 14P3, 14-lead (0.300"/7.62 mm Wide) Plastic Dual Inline Package (PDIP) 14P3 B 2010-10-20 PIN 1 E1 A1 B E B1 C L SEATING PLANE A D e eB eC COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A – – 5.334 A1 0.381 – – D 18.669 – 19.685 Note 2 E 7.620 – 8.255 E1 6.096 – 7.112 Note 2 B 0.356 – 0.559 B1 1.143 – 1.778 L 2.921 – 3.810 C 0.203 – 0.356 eB – – 10.922 eC 0.000 – 1.524 e 2.540 TYP Notes: 1. This package conforms to JEDEC reference MS-001, Variation AA. 2. Dimensions D and E1 do not include mold Flash or Protrusion. Mold Flash or Protrusion shall not exceed 0.25 mm (0.010"). 275 8183F–AVR–06/12 ATtiny24A/44A/84A 25.3 15CC1 TITLE GPC DRAWING NO. REV. Package Drawing Contact: R packagedrawings@atmel.com CBC C 15CC1, 15-ball (4 x 4 Array), 3.0 x 3.0 x 0.6 mm package, ball pitch 0.65 mm, Ultra thin, Fine-Pitch Ball Grid Array Package (UFBGA) 15CC1 07/06/10 A – – 0.60 A1 0.12 – – A2 0.38 REF b 0.25 0.30 0.35 1 b1 0.25 – – 2 D 2.90 3.00 3.10 D1 1.95 BSC E 2.90 3.00 3.10 E1 1.95 BSC e 0.65 BSC COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE TOP VIEW 123 4 A B C D E D 15-Øb D C B A Pin#1 ID 0.08 A1 A D1 E1 A2 A1 BALL CORNER e 123 4 SIDE VIEW b1 BOTTOM VIEW e Note1: Dimension “b” is measured at the maximum ball dia. in a plane parallel to the seating plane. Note2: Dimension “b1” is the solderable surface defined by the opening of the solder resist layer.276 8183F–AVR–06/12 ATtiny24A/44A/84A 25.4 20M1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 20M1, 20-pad, 4 x 4 x 0.8 mm Body, Lead Pitch 0.50 mm, 20M1 B 10/27/04 2.6 mm Exposed Pad, Micro Lead Frame Package (MLF) A 0.70 0.75 0.80 A1 – 0.01 0.05 A2 0.20 REF b 0.18 0.23 0.30 D 4.00 BSC D2 2.45 2.60 2.75 E 4.00 BSC E2 2.45 2.60 2.75 e 0.50 BSC L 0.35 0.40 0.55 SIDE VIEW Pin 1 ID Pin #1 Notch (0.20 R) BOTTOM VIEW TOP VIEW Note: Reference JEDEC Standard MO-220, Fig. 1 (SAW Singulation) WGGD-5. COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE D E e A2 A1 A D2 E2 0.08 C L 1 2 3 b 1 2 3277 8183F–AVR–06/12 ATtiny24A/44A/84A 25.5 20M2 TITLE GPC DRAWING NO. REV. Package Drawing Contact: packagedrawings@atmel.com ZFC B 20M2 20M2, 20-pad, 3 x 3 x 0.85 mm Body, Lead Pitch 0.45 mm, 1.55 x 1.55 mm Exposed Pad, Thermally Enhanced Plastic Very Thin Quad Flat No Lead Package (VQFN) 10/24/08 15 14 13 12 11 1 2 3 4 5 16 17 18 19 20 10 9 8 7 6 D2 E2 e b L K Pin #1 Chamfer (C 0.3) D E SIDE VIEW A1 y Pin 1 ID BOTTOM VIEW TOP VIEW A C C0.18 (8X) 0.3 Ref (4x) COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A 0.75 0.80 0.85 A1 0.00 0.02 0.05 b 0.17 0.22 0.27 C 0.152 D 2.90 3.00 3.10 D2 1.40 1.55 1.70 E 2.90 3.00 3.10 E2 1.40 1.55 1.70 e – 0.45 – L 0.35 0.40 0.45 K 0.20 – – y 0.00 – 0.08 278 8183F–AVR–06/12 ATtiny24A/44A/84A 26. Errata The revision letters in this section refer to the revision of the corresponding ATtiny24A/44A/84A device. 26.1 ATtiny24A 26.1.1 Rev. H No known errata. 26.1.2 Rev. G Not sampled. 26.1.3 Rev. F Not sampled. 26.2 ATtiny44A 26.2.1 Rev. G No known errata. Yield improvement. 26.2.2 Rev. F No known errata. 26.2.3 Rev. E Not sampled. 26.3 ATtiny84A 26.3.1 Rev. C No known errata.279 8183F–AVR–06/12 ATtiny24A/44A/84A 27. Datasheet Revision History 27.1 Rev. 8183F – 06/12 1. Updated: – Table 16-1 on page 138 – Figure 16-7 on page 137 – “Ordering Information” on page 270 27.2 Rev. 8183E – 01/12 1. Updated: – Production status for ATtiny24A and ATtiny84A – “Start Condition Detector” on page 122 – “Ordering Information” on page 270, 271, and 272 27.3 Rev. 8183D – 04/11 1. Added errata for ATtiny44A rev. G in Section 26. “Errata” on page 278 27.4 Rev. 8183C – 03/11 1. Added: – ATtiny84A, including typical characteristics plots – Section 3.3 “Capacitive Touch Sensing” on page 6 – Table 6-8, “Capacitance of Low-Frequency Crystal Oscillator,” on page 28 – Analog Comparator Offset plots for ATtiny24A (Figure 21.2.10 on page 208) and ATtiny44A (Figure 21.3.11 on page 236) – Extended temperature part numbers in Section 24. “Ordering Information” on page 270 2. Updated: – Bit syntax throughout the datasheet, e.g. from CS02:0 to CS0[2:0] – Section 6.4 “Clock Output Buffer” on page 30, changed CLKO to CKOUT – Table 16-4, “Single-Ended Input channel Selections,” on page 145, added note for Internal 1.1V Reference – Table 19-16, “High-voltage Serial Programming Instruction Set for ATtiny24A/44A/84A,” on page 170, adjusted notes – Table 20-1, “DC Characteristics. TA = -40°C to +85°C,” on page 173, adjusted notes 27.5 Rev. 8183B – 03/10 1. Updated template. 2. Added UFBGA package (15CC1) in: “Features” on page 1, “Pin Configurations” on page 2, Section 24. “Ordering Information” on page 270, and Section 25.3 “15CC1” on page 275. 3. Separated typical characteristic plots, added Section 21.2 “ATtiny24A” on page 183. 4. Updated sections: – Section 14.5.4 “USIBR – USI Buffer Register” on page 127, header updated280 8183F–AVR–06/12 ATtiny24A/44A/84A – Section 24. “Ordering Information” on page 270, added tape & reel and topside marking, updated notes 5. Updated Figures: – Figure 4-1 “Block Diagram of the AVR Architecture” on page 7 – Figure 8-1 “Reset Logic” on page 38 – Figure 14-1 “Universal Serial Interface, Block Diagram” on page 116, USIDB -> USIBR – Figure 19-5 “High-voltage Serial Programming Waveforms” on page 169 6. Updated Tables: – Table 19-11, “Minimum Wait Delay Before Writing the Next Flash or EEPROM Location,” on page 164, updated value for tWD_ERASE 27.6 Rev. 8183A – 12/08 1. Initial revision. Created from document 8006H. 2. Updated "Ordering Information" on page 278 and page 278. Pb-plated packages are no longer offered and there are no separate ordering codes for commercial operation range, the only available option now is industrial. Also, updated some order codes to reflect changes in leadframe composition and added VQFN package option. 3. Updated data sheet template. 4. Removed all references to 8K device. 5. Updated characteristic plots of section “Typical Characteristics”, starting on page 182. 6. Added characteristic plots: – “Bandgap Voltage vs. Supply Voltage” on page 233 – “Bandgap Voltage vs. Temperature” on page 233 7. Updated sections: – “Features” on page 1 – “Power Reduction Register” on page 35 – “Analog Comparator” on page 128 – “Features” on page 132 – “Operation” on page 133 – “Starting a Conversion” on page 134 – “ADC Voltage Reference” on page 139 – “Speed” on page 174 8. Updated Figures: – “Program Memory Map” on page 15 – “Data Memory Map” on page 16 9. Update Tables: – “Device Signature Bytes” on page 161 – “DC Characteristics. TA = -40°C to +85°C” on page 173 – “Additional Current Consumption for the different I/O modules (absolute values)” on page 182 – “Additional Current Consumption (percentage) in Active and Idle mode” on page 183i 8183F–AVR–06/12 ATtiny24A/44A/84A Table of Contents Features ..................................................................................................... 1 1 Pin Configurations ................................................................................... 2 1.1 Pin Descriptions .................................................................................................3 2 Overview ................................................................................................... 4 3 General Information ................................................................................. 6 3.1 Resources .........................................................................................................6 3.2 Code Examples .................................................................................................6 3.3 Capacitive Touch Sensing .................................................................................6 3.4 Data Retention ...................................................................................................6 3.5 Disclaimer ..........................................................................................................6 4 CPU Core .................................................................................................. 7 4.1 Architectural Overview .......................................................................................7 4.2 ALU – Arithmetic Logic Unit ...............................................................................8 4.3 Status Register ..................................................................................................8 4.4 General Purpose Register File ..........................................................................9 4.5 Stack Pointer ...................................................................................................10 4.6 Instruction Execution Timing ...........................................................................10 4.7 Reset and Interrupt Handling ...........................................................................11 4.8 Register Description ........................................................................................13 5 Memories ................................................................................................ 15 5.1 In-System Re-programmable Flash Program Memory ....................................15 5.2 SRAM Data Memory ........................................................................................15 5.3 EEPROM Data Memory ..................................................................................16 5.4 I/O Memory ......................................................................................................20 5.5 Register Description ........................................................................................20 6 Clock System ......................................................................................... 24 6.1 Clock Subsystems ...........................................................................................24 6.2 Clock Sources .................................................................................................25 6.3 System Clock Prescaler ..................................................................................30 6.4 Clock Output Buffer .........................................................................................30 6.5 Register Description ........................................................................................31 7 Power Management and Sleep Modes ................................................. 33ii 8183F–AVR–06/12 ATtiny24A/44A/84A 7.1 Sleep Modes ....................................................................................................33 7.2 Software BOD Disable .....................................................................................34 7.3 Power Reduction Register ...............................................................................35 7.4 Minimizing Power Consumption ......................................................................35 7.5 Register Description ........................................................................................36 8 System Control and Reset .................................................................... 38 8.1 Resetting the AVR ...........................................................................................38 8.2 Reset Sources .................................................................................................39 8.3 Internal Voltage Reference ..............................................................................41 8.4 Watchdog Timer ..............................................................................................41 8.5 Register Description ........................................................................................44 9 Interrupts ................................................................................................ 47 9.1 Interrupt Vectors ..............................................................................................47 9.2 External Interrupts ...........................................................................................48 9.3 Register Description ........................................................................................50 10 I/O Ports .................................................................................................. 53 10.1 Ports as General Digital I/O .............................................................................54 10.2 Alternate Port Functions ..................................................................................58 10.3 Register Description ........................................................................................66 11 8-bit Timer/Counter0 with PWM ............................................................ 68 11.1 Features ..........................................................................................................68 11.2 Overview ..........................................................................................................68 11.3 Clock Sources .................................................................................................69 11.4 Counter Unit ....................................................................................................69 11.5 Output Compare Unit .......................................................................................70 11.6 Compare Match Output Unit ............................................................................72 11.7 Modes of Operation .........................................................................................73 11.8 Timer/Counter Timing Diagrams .....................................................................77 11.9 Register Description ........................................................................................79 12 16-bit Timer/Counter1 ............................................................................ 85 12.1 Features ..........................................................................................................85 12.2 Overview ..........................................................................................................85 12.3 Timer/Counter Clock Sources .........................................................................87 12.4 Counter Unit ....................................................................................................87iii 8183F–AVR–06/12 ATtiny24A/44A/84A 12.5 Input Capture Unit ...........................................................................................88 12.6 Output Compare Units .....................................................................................90 12.7 Compare Match Output Unit ............................................................................92 12.8 Modes of Operation .........................................................................................94 12.9 Timer/Counter Timing Diagrams ...................................................................101 12.10 Accessing 16-bit Registers ............................................................................103 12.11 Register Description ......................................................................................106 13 Timer/Counter Prescaler ..................................................................... 113 13.1 Prescaler Reset .............................................................................................113 13.2 External Clock Source ...................................................................................113 13.3 Register Description ......................................................................................114 14 USI – Universal Serial Interface .......................................................... 116 14.1 Features ........................................................................................................116 14.2 Overview ........................................................................................................116 14.3 Functional Descriptions .................................................................................117 14.4 Alternative USI Usage ...................................................................................123 14.5 Register Descriptions ....................................................................................123 15 Analog Comparator ............................................................................. 128 15.1 Analog Comparator Multiplexed Input ...........................................................128 15.2 Register Description ......................................................................................129 16 Analog to Digital Converter ................................................................ 132 16.1 Features ........................................................................................................132 16.2 Overview ........................................................................................................132 16.3 Operation .......................................................................................................133 16.4 Starting a Conversion ....................................................................................134 16.5 Prescaling and Conversion Timing ................................................................135 16.6 Changing Channel or Reference Selection ...................................................138 16.7 ADC Noise Canceler .....................................................................................139 16.8 Analog Input Circuitry ....................................................................................139 16.9 Noise Canceling Techniques .........................................................................140 16.10 ADC Accuracy Definitions .............................................................................140 16.11 ADC Conversion Result .................................................................................142 16.12 Temperature Measurement ...........................................................................143 16.13 Register Description ......................................................................................144iv 8183F–AVR–06/12 ATtiny24A/44A/84A 17 debugWIRE On-chip Debug System .................................................. 150 17.1 Features ........................................................................................................150 17.2 Overview ........................................................................................................150 17.3 Physical Interface ..........................................................................................150 17.4 Software Break Points ...................................................................................151 17.5 Limitations of debugWIRE .............................................................................151 17.6 Register Description ......................................................................................151 18 Self-Programming the Flash ............................................................... 152 18.1 Performing Page Erase by SPM ....................................................................152 18.2 Filling the Temporary Buffer (Page Loading) .................................................152 18.3 Performing a Page Write ...............................................................................153 18.4 Addressing the Flash During Self-Programming ...........................................153 18.5 EEPROM Write Prevents Writing to SPMCSR ..............................................154 18.6 Reading Lock, Fuse and Signature Data from Software ...............................154 18.7 Preventing Flash Corruption ..........................................................................156 18.8 Programming Time for Flash when Using SPM ............................................156 18.9 Register Description ......................................................................................156 19 Memory Programming ......................................................................... 158 19.1 Program And Data Memory Lock Bits ...........................................................158 19.2 Fuse Bytes .....................................................................................................159 19.3 Device Signature Imprint Table .....................................................................160 19.4 Page Size ......................................................................................................161 19.5 Serial Programming .......................................................................................162 19.6 High-voltage Serial Programming ..................................................................166 19.7 High-Voltage Serial Programming Algorithm .................................................166 20 Electrical Characteristics .................................................................... 173 20.1 Absolute Maximum Ratings* .........................................................................173 20.2 DC Characteristics .........................................................................................173 20.3 Speed ............................................................................................................174 20.4 Clock Characteristics .....................................................................................175 20.5 System and Reset Characteristics ................................................................176 20.6 ADC Characteristics ......................................................................................177 20.7 Analog Comparator Characteristics ...............................................................180 20.8 Serial Programming Characteristics ..............................................................180 20.9 High-Voltage Serial Programming Characteristics ........................................181v 8183F–AVR–06/12 ATtiny24A/44A/84A 21 Typical Characteristics ........................................................................ 182 21.1 Supply Current of I/O Modules ......................................................................182 21.2 ATtiny24A ......................................................................................................183 21.3 ATtiny44A ......................................................................................................211 21.4 ATtiny84A ......................................................................................................239 22 Register Summary ............................................................................... 266 23 Instruction Set Summary .................................................................... 268 24 Ordering Information ........................................................................... 270 24.1 ATtiny24A ......................................................................................................270 24.2 ATtiny44A ......................................................................................................271 24.3 ATtiny84A ......................................................................................................272 25 Packaging Information ........................................................................ 273 25.1 14S1 ..............................................................................................................273 25.2 14P3 ..............................................................................................................274 25.3 15CC1 ...........................................................................................................275 25.4 20M1 ..............................................................................................................276 25.5 20M2 ..............................................................................................................277 26 Errata ..................................................................................................... 278 26.1 ATtiny24A ......................................................................................................278 26.2 ATtiny44A ......................................................................................................278 26.3 ATtiny84A ......................................................................................................278 27 Datasheet Revision History ................................................................ 279 27.1 Rev. 8183F – 06/12 .......................................................................................279 27.2 Rev. 8183E – 01/12 .......................................................................................279 27.3 Rev. 8183D – 04/11 .......................................................................................279 27.4 Rev. 8183C – 03/11 .......................................................................................279 27.5 Rev. 8183B – 03/10 .......................................................................................279 27.6 Rev. 8183A – 12/08 .......................................................................................2808183F–AVR–06/12 Headquarters International Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: (+1)(408) 441-0311 Fax: (+1)(408) 487-2600 Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 JAPAN Tel: (+81)(3) 3523-3551 Fax: (+81)(3) 3523-7581 Product Contact Web Site www.atmel.com Technical Support avr@atmel.com Sales Contact www.atmel.com/contacts Literature Requests www.atmel.com/literature Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDITIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. © 2012 Atmel Corporation. All rights reserved. Atmel®, logo and combinations thereof, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Atmel Xplained Pro Atmel® Xplained Pro kits provide a complete and easy to use low-cost development platform for evaluating and prototyping your Atmel Flash-based microcontrollers (MCUs) designs. The Xplained Pro kits offer expansion ports that allow you to connect extension boards to provide more system functionality including OLED LCD displays, buttons, sensors and more, for fast application prototyping. You can purchase add-on boards from Atmel, or build your own. The new kits are part of Atmel’s complete MCU tools ecosystem, working seamlessly with Atmel Studio 6 IDP that includes over 1600 example projects from Atmel Software Framework. 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Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T : (+1)(408) 441. 0311 F : (+1)(408) 436. 4200 | www.atmel.com Evaluation Kit Contents SAP Code Price SAM4L Xplained Pro Evaluation Kit SAM4L MCU Board ATSAM4L-XPRO $39 SAM4S Xplained Pro Evaluation Kit SAM4S MCU Board ATSAM4S-XPRO $39 ATmega256RFR2 Xplained Pro Evaluation Kit ATmega256RFR2 MCU Board ATMEGA256RFR2-XPRO $39 SAM4L Xplained Pro Starter Kit SAM4L MCU Board 4 Extension Boards: Segment LCD, OLED Display, I/O, Prototyping ATSAM4L-XSTK $109 SAM4S Xplained Pro Starter Kit SAM4S MCU Board 3 Extension Boards: OLED Display, I/O, Prototyping ATSAM4S-XSTK $99 RFR2 Xplained Pro Starter Kit 3 Extension Boards: OLED Display, I/O, Prototyping ATMEGA256RFR2-XSTK $99 OLED Xplained Pro Extension Extension board with 128x32 OLED Display, 3 Buttons and 3 LEDs ATOLED1-XPRO $22 Segment LCD Xplained Pro Extension Extension Board with LCD Segment Display ATSLCD1-XPRO $22 I/O Xplained Pro Extension Extension Board with Light Sensor, Temperature Sensor, Micro SD Card, UART Loopback ATIO1-XPRO $27 Prototyping Xplained Pro Extension Prototyping Extension Board with Bread-boarding Area ATPROTO1-XPRO $18 Not recommended for new designs - Use XMEGA A1U series 8067O–AVR–06/2013 Features  High-performance, low-power Atmel® AVR® XMEGA® 8/16-bit Microcontroller  Nonvolatile program and data memories  64K - 128KBytes of in-system self-programmable flash  4K - 8KBytes boot section  2 KBBytes EEPROM  4 KB - 8 KBBytes internal SRAM  External bus interface for up to 16Mbytes SRAM  External bus interface for up to 128Mbit SDRAM  Peripheral features  Four-channel DMA controller  Eight-channel event system  Eight 16-bit timer/counters  Four timer/counters with 4 output compare or input capture channels  Four timer/counters with 2 output compare or input capture channels  High resolution extension on all timer/counters  Advanced waveform extension (AWeX) on two timer/counters  Eight USARTs with IrDA support for one USART  Four two-wire interfaces with dual address match (I2 C and SMBus compatible)  Four serial peripheral interfaces (SPIs)  AES and DES crypto engine  16-bit real time counter (RTC) with separate oscillator  Two sixteen channel, 12-bit, 2msps Analog to Digital Converters  Two two-channel, 12-bit, 1msps Digital to Analog Converters  Four Analog Comparators (ACs) with window compare function, and current sources  External interrupts on all general purpose I/O pins  Programmable watchdog timer with separate on-chip ultra low power oscillator  QTouch® library support  Capacitive touch buttons, sliders and wheels  Special microcontroller features  Power-on reset and programmable brown-out detection  Internal and external clock options with PLL and prescaler  Programmable multilevel interrupt controller  Five sleep modes  Programming and debug interfaces  JTAG (IEEE 1149.1 compliant) interface, including boundary scan  PDI (Program and Debug Interface)  I/O and packages  78 Programmable I/O pins  100 lead TQFP  100 ball BGA  100 ball VFBGA  Operating voltage  1.6 – 3.6V  Operating frequency  0 – 12MHz from 1.6V  0 – 32MHz from 2.7V 8/16-bit XMEGA A1 Microcontroller ATxmega128A1 / ATxmega64A1 Preliminary 8067O–AVR–06/2013 Not recommended for new designs - Use XMEGA A1U series[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 2 8067O–AVR–06/2013 ‘ 1. Ordering Information Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information. 2. Pb-free packaging, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. For packaging information, see “Packaging information” on page 70. Typical Applications Ordering Code Flash (B) E2 SRAM Speed (MHz) Power Supply Package(1)(2)(3) Temp ATxmega128A1-AU 128K + 8K 2 KB 8 KB 32 1.6 - 3.6V 100A -40C - 85C ATxmega128A1-AUR ATxmega64A1-AU 64K + 4K 2 KB 4 KB ATxmega64A1-AUR ATxmega128A1-CU 128K + 8K 2 KB 8 KB 100C1 ATxmega128A1CUR ATxmega64A1-CU 64K + 4K 2 KB 4 KB ATxmega64A1-CUR ATxmega128A1-C7U 128K + 8K 2 KB 8 KB 100C2 ATxmega128A1-C7UR ATxmega64A1-C7U 64K + 4K 2 KB 4 KB ATxmega64A1-C7UR Package Type 100A 100-lead, 14 x 14 x 1.0mm, 0.5mm lead pitch, thin profile plastic quad flat package (TQFP) 100C1 100-ball, 9 x 9 x 1.2mm body, ball pitch 0.88mm, chip ball grid array (CBGA) 100C2 100-ball, 7 x 7 x 1.0mm body, ball pitch 0.65mm, very thin fine-pitch ball grid array (VFBGA) Industrial control Climate control Low power battery applications Factory automation RF and ZigBee® Power tools Building control Sensor control HVAC Board control Optical Utility metering White goods Medical applications[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 3 8067O–AVR–06/2013 2. Pinout/Block Diagram Figure 2-1. Block diagram and pinout Notes: 1. For full details on pinout and pin functions refer to “Pinout and Pin Functions” on page 55. 2. VCC/GND on pin 83/84 are swapped compared to other VCC/GND to allow easier routing of GND to 32kHz crystal. INDEX CORNER PA6 PA7 GND AVCC PB0 PB1 PB2 PB3 PB4 PB5 PB6 PB7 GND VCC PC0 PC1 PC2 PC3 PC4 PC5 PC6 PC7 GND VCC PD0 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 PD1 PD2 PD3 PD4 PD5 PD6 PD7 GND VCC PE0 PE1 PE2 PE3 PE4 PE5 PE6 PE7 GND VCC PF0 PF1 PF2 PF3 PF4 PF5 PK0 VCC GND PJ7 PJ6 PJ5 PJ4 PJ3 PJ2 PJ1 PJ0 VCC GND PH7 PH6 PH5 PH4 PH3 PH2 PH1 PH0 VCC GND PF7 PF6 PA5 PA4 PA3 PA2 PA1 PA0 AVCC GND PR1 PR0 RESET/PDI PDI PQ3 PQ2 PQ1 PQ0 GND VCC PK7 PK6 PK5 PK4 PK3 PK2 PK1 FLASH RAM E 2PROM DMA Interrupt Controlle r OCD External Bus Interface ADC A ADC B DAC B DAC A AC A0 AC A1 AC B0 AC B1 Port A Port B Event System ctrl Port K Port J Port H Port R Port Q Power Contro l Reset Contro l Watchdog OSC/CLK Contro l BOD POR RTC EVENT ROUTING NETWORK DATA BU S DATA BU S VREF TEMP Port C CPU T/C0:1 USART0:1 TWI SPI Port D Port E Port F T/C0:1 USART0/1 TWI SPI T/C0:1 USART0:1 TWI SPI T/C0:1 USART0:1 TWI SPI[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 4 8067O–AVR–06/2013 Figure 2-2. CBGA-pinout Table 2-1. CBGA-pinout. 1 2 3 4 5 6 7 8 9 10 A PK0 VCC GND PJ3 VCC GND PH1 GND VCC PF7 B PK3 PK2 PK1 PJ4 PH7 PH4 PH2 PH0 PF6 PF5 C VCC PK5 PK4 PJ5 PJ0 PH5 PH3 PF2 PF3 VCC D GND PK6 PK7 PJ6 PJ1 PH6 PF0 PF1 PF4 GND E PQ0 PQ1 PQ2 PJ7 PJ2 PE7 PE6 PE5 PE4 PE3 F PR1 PR0 RESET/ PDI PDI PQ3 PC2 PE2 PE1 PE0 VCC G GND PA1 PA4 PB3 PB4 PC1 PC6 PD7 PD6 GND H AVCC PA2 PA5 PB2 PB5 PC0 PC5 PD5 PD4 PD3 J PA0 PA3 PB0 PB1 PB6 PC3 PC4 PC7 PD2 PD1 K PA6 PA7 GND AVCC PB7 VCC GND VCC GND PD0 A B C D E F G H J K 1 2 3 4 5 6 7 8 9 10 A B C D E F G H J K 10 9 8 7 6 5 4 3 2 1 Top view Bottom view[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 5 8067O–AVR–06/2013 3. Overview The Atmel AVR XMEGA is a family of low power, high performance, and peripheral rich 8/16-bit microcontrollers based on the AVR enhanced RISC architecture. By executing instructions in a single clock cycle, the AVR XMEGA devices achieve CPU throughput approaching one million instructions per second (MIPS) per megahertz, allowing the system designer to optimize power consumption versus processing speed. The Atmel AVR CPU combines a rich instruction set with 32 general purpose working registers. All 32 registers are directly connected to the arithmetic logic unit (ALU), allowing two independent registers to be accessed in a single instruction, executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs many times faster than conventional single-accumulator or CISC based microcontrollers. The AVR XMEGA A1 devices provide the following features: in-system programmable flash with read-while-write capabilities; internal EEPROM and SRAM; four-channel DMA controller, eight-channel event system and programmable multilevel interrupt controller, 78 general purpose I/O lines, 16-bit real-time counter (RTC); eight flexible, 16-bit timer/counters with compare and PWM channels, eight USARTs; four two-wire serial interfaces (TWIs); four serial peripheral interfaces (SPIs); AES and DES cryptographic engine; two 16-channel, 12-bit ADCs with programmable gain; two 2-channel, 12-bit DACs; four Analog Comparators (ACs) with window mode; programmable watchdog timer with separate internal oscillator; accurate internal oscillators with PLL and prescaler; and programmable brown-out detection. The program and debug interface (PDI), a fast, two-pin interface for programming and debugging, is available. The devices also have an IEEE std. 1149.1 compliant JTAG interface, and this can also be used for boundary scan, on-chip debug and programming. The XMEGA A1 devices have five software selectable power saving modes. The idle mode stops the CPU while allowing the SRAM, DMA controller, event system, interrupt controller, and all peripherals to continue functioning. The powerdown mode saves the SRAM and register contents, but stops the oscillators, disabling all other functions until the next TWI or pin-change interrupt, or reset. In power-save mode, the asynchronous real-time counter continues to run, allowing the application to maintain a timer base while the rest of the device is sleeping. In standby mode, the external crystal oscillator keeps running while the rest of the device is sleeping. This allows very fast startup from the external crystal, combined with low power consumption. In extended standby mode, both the main oscillator and the asynchronous timer continue to run. To further reduce power consumption, the peripheral clock to each individual peripheral can optionally be stopped in active mode and idle sleep mode. Atmel offers a free QTouch library for embedding capacitive touch buttons, sliders and wheels functionality into AVR microcontrollers. The device are manufactured using Atmel high-density, nonvolatile memory technology. The program flash memory can be reprogrammed in-system through the PDI or JTAG interfaces. A boot loader running in the device can use any interface to download the application program to the flash memory. The boot loader software in the boot flash section will continue to run while the application flash section is updated, providing true read-while-write operation. By combining an 8/16-bit RISC CPU with in-system, self-programmable flash, the AVR XMEGA is a powerful microcontroller family that provides a highly flexible and cost effective solution for many embedded applications. All Atmel AVR XMEGA devices are supported with a full suite of program and system development tools, including C compilers, macro assemblers, program debugger/simulators, programmers, and evaluation kits.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 6 8067O–AVR–06/2013 3.1 Block Diagram Figure 3-1. XMEGA A1 Block Diagram VBAT Power Supervision Battery Backup Controller Real Time Counter 32.768 kHz XOSC Power Supervision POR/BOD & RESET PORT A (8) PORT B (8) EVENT ROUTING NETWORK DMA Controller BUS Matrix SRAM EBI ADCA DACA ACA DACB ADCB ACB OCD PORT K (8) PORT J (8) PORT H (8) PDI Watchdog Timer Watchdog Oscillator Interrupt Controller DATA BUS Prog/Debug Controller PORT R (2) Oscillator Circuits/ Clock Generation Oscillator Control Real Time Counter Event System Controller JTAG Sleep Controller DES IRCOM PORT G (8) PORT L (8) PORT Q (8) PORT M (8) PORT C (8) TCC0:1 USARTC0:1 SPIC TWIC PORT D (8) TCD0:1 USARTD0:1 SPID TWID TCF0:1 USARTF0:1 SPIF TWIF TCE0:1 USARTE0:1 SPIE TWIE PORT E (8) PORT F (8) EVENT ROUTING NETWORK AES AREFA AREFB PORT N (8) PORT P (8) CPU NVM Controller Flash EEPROM DATA BUS Int. Refs. Tempref Digital function Analog function Bus masters / Programming / Debug Oscillator / Crystal / Clock General Purpose I/O EBI[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 7 8067O–AVR–06/2013 4. Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. 4.1 Recommended reading  XMEGA A Manual  XMEGA A Application Notes This device data sheet only contains part specific information and a short description of each peripheral and module. The XMEGA A Manual describes the modules and peripherals in depth. The XMEGA A application notes contain example code and show applied use of the modules and peripherals. The XMEGA A Manual and Application Notes are available from http://www.atmel.com/avr. 5. Capacitive touch sensing The Atmel QTouch library provides a simple to use solution to realize touch sensitive interfaces on most Atmel AVR microcontrollers. The patented charge-transfer signal acquisition offers robust sensing and includes fully debounced reporting of touch keys and includes Adjacent Key Suppression® (AKS®) technology for unambiguous detection of key events. The QTouch library includes support for the QTouch and QMatrix acquisition methods. Touch sensing can be added to any application by linking the appropriate Atmel QTouch library for the AVR microcontroller. This is done by using a simple set of APIs to define the touch channels and sensors, and then calling the touch sensing API’s to retrieve the channel information and determine the touch sensor states. The QTouch library is FREE and downloadable from the Atmel website at the following location: www.atmel.com/qtouchlibrary. For implementation details and other information, refer to the QTouch library user guide - also available for download from the Atmel website. 6. Disclaimer For devices that are not available yet, typical values contained in this datasheet are based on simulations and characterization of other AVR XMEGA microcontrollers manufactured on the same process technology. Min. and Max values will be available after the device is characterized.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 8 8067O–AVR–06/2013 7. AVR CPU 7.1 Features  8/16-bit high performance AVR RISC Architecture  138 instructions  Hardware multiplier  32x8-bit registers directly connected to the ALU  Stack in SRAM  Stack Pointer accessible in I/O memory space  Direct addressing of up to 16M Bytes of program and data memory  True 16/24-bit access to 16/24-bit I/O registers  Support for 8-, 16- and 32-bit Arithmetic  Configuration Change Protection of system critical features 7.2 Overview All Atmel AVR XMEGA devices use the 8/16-bit AVR CPU. The main function of the CPU is to execute the code and perform all calculations. The CPU is able to access memories, perform calculations, control peripherals, and execute the program in the flash memory. Interrupt handling is described in a separate section, refer to “Interrupts and Programmable Multilevel Interrupt Controller” on page 29. 7.3 Architectural Overview In order to maximize performance and parallelism, the AVR CPU uses a Harvard architecture with separate memories and buses for program and data. Instructions in the program memory are executed with single-level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This enables instructions to be executed on every clock cycle. For details of all AVR instructions, refer to http://www.atmel.com/avr.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 9 8067O–AVR–06/2013 Figure 7-1. Block diagram of the AVR CPU architecture. The arithmetic logic unit (ALU) supports arithmetic and logic operations between registers or between a constant and a register. Single-register operations can also be executed in the ALU. After an arithmetic operation, the status register is updated to reflect information about the result of the operation. The ALU is directly connected to the fast-access register file. The 32 x 8-bit general purpose working registers all have single clock cycle access time allowing single-cycle arithmetic logic unit (ALU) operation between registers or between a register and an immediate. Six of the 32 registers can be used as three 16-bit address pointers for program and data space addressing, enabling efficient address calculations. The memory spaces are linear. The data memory space and the program memory space are two different memory spaces. The data memory space is divided into I/O registers, SRAM, and external RAM. In addition, the EEPROM can be memory mapped in the data memory. All I/O status and control registers reside in the lowest 4KB addresses of the data memory. This is referred to as the I/O memory space. The lowest 64 addresses can be accessed directly, or as the data space locations from 0x00 to 0x3F. The rest is the extended I/O memory space, ranging from 0x0040 to 0x0FFF. I/O registers here must be accessed as data space locations using load (LD/LDS/LDD) and store (ST/STS/STD) instructions. The SRAM holds data. Code execution from SRAM is not supported. It can easily be accessed through the five different addressing modes supported in the AVR architecture. The first SRAM address is 0x2000. Data addresses 0x1000 to 0x1FFF are reserved for memory mapping of EEPROM. The program memory is divided in two sections, the application program section and the boot program section. Both sections have dedicated lock bits for write and read/write protection. The SPM instruction that is used for selfprogramming of the application flash memory must reside in the boot program section. The application section contains an application table section with separate lock bits for write and read/write protection. The application table section can be used for safe storing of nonvolatile data in the program memory.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 10 8067O–AVR–06/2013 7.4 ALU - Arithmetic Logic Unit The arithmetic logic unit (ALU) supports arithmetic and logic operations between registers or between a constant and a register. Single-register operations can also be executed. The ALU operates in direct connection with all 32 general purpose registers. In a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed and the result is stored in the register file. After an arithmetic or logic operation, the status register is updated to reflect information about the result of the operation. ALU operations are divided into three main categories – arithmetic, logical, and bit functions. Both 8- and 16-bit arithmetic is supported, and the instruction set allows for efficient implementation of 32-bit aritmetic. The hardware multiplier supports signed and unsigned multiplication and fractional format. 7.4.1 Hardware Multiplier The multiplier is capable of multiplying two 8-bit numbers into a 16-bit result. The hardware multiplier supports different variations of signed and unsigned integer and fractional numbers:  Multiplication of unsigned integers  Multiplication of signed integers  Multiplication of a signed integer with an unsigned integer  Multiplication of unsigned fractional numbers  Multiplication of signed fractional numbers  Multiplication of a signed fractional number with an unsigned one A multiplication takes two CPU clock cycles. 7.5 Program Flow After reset, the CPU starts to execute instructions from the lowest address in the flash program memory ‘0.’ The program counter (PC) addresses the next instruction to be fetched. Program flow is provided by conditional and unconditional jump and call instructions capable of addressing the whole address space directly. Most AVR instructions use a 16-bit word format, while a limited number use a 32-bit format. During interrupts and subroutine calls, the return address PC is stored on the stack. The stack is allocated in the general data SRAM, and consequently the stack size is only limited by the total SRAM size and the usage of the SRAM. After reset, the stack pointer (SP) points to the highest address in the internal SRAM. The SP is read/write accessible in the I/O memory space, enabling easy implementation of multiple stacks or stack areas. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR CPU. 7.6 Status Register The status register (SREG) contains information about the result of the most recently executed arithmetic or logic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the status register is updated after all ALU operations, as specified in the instruction set reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The status register is not automatically stored when entering an interrupt routine nor restored when returning from an interrupt. This must be handled by software. The status register is accessible in the I/O memory space. 7.6.1 Stack and Stack Pointer The stack is used for storing return addresses after interrupts and subroutine calls. It can also be used for storing temporary data. The stack pointer (SP) register always points to the top of the stack. It is implemented as two 8-bit registers that are accessible in the I/O memory space. Data are pushed and popped from the stack using the PUSH and POP instructions. The stack grows from a higher memory location to a lower memory location. This implies that pushing data onto the stack decreases the SP, and popping data off the stack increases the SP. The SP is automatically loaded [Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 11 8067O–AVR–06/2013 after reset, and the initial value is the highest address of the internal SRAM. If the SP is changed, it must be set to point above address 0x2000, and it must be defined before any subroutine calls are executed or before interrupts are enabled. During interrupts or subroutine calls, the return address is automatically pushed on the stack. The return address can be two or three bytes, depending on program memory size of the device. For devices with 128KB or less of program memory, the return address is two bytes, and hence the stack pointer is decremented/incremented by two. For devices with more than 128KB of program memory, the return address is three bytes, and hence the SP is decremented/incremented by three. The return address is popped off the stack when returning from interrupts using the RETI instruction, and from subroutine calls using the RET instruction. The SP is decremented by one when data are pushed on the stack with the PUSH instruction, and incremented by one when data is popped off the stack using the POP instruction. To prevent corruption when updating the stack pointer from software, a write to SPL will automatically disable interrupts for up to four instructions or until the next I/O memory write. After reset the stack pointer is initialized to the highest address of the SRAM. See Table 8-2 on page 15. 7.7 Register File The register file consists of 32 x 8-bit general purpose working registers with single clock cycle access time. The register file supports the following input/output schemes:  One 8-bit output operand and one 8-bit result input  Two 8-bit output operands and one 8-bit result input  Two 8-bit output operands and one 16-bit result input  One 16-bit output operand and one 16-bit result input Six of the 32 registers can be used as three 16-bit address register pointers for data space addressing, enabling efficient address calculations. One of these address pointers can also be used as an address pointer for lookup tables in flash program memory.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 12 8067O–AVR–06/2013 8. Memories 8.1 Features  Flash Program Memory  One linear address space  In-System Programmable  Self-Programming and Bootloader support  Application Section for application code  Application Table Section for application code or data storage  Boot Section for application code or bootloader code  Separate lock bits and protection for all sections  Built in fast CRC check of a selectable flash program memory section  Data Memory  One linear address space  Single cycle access from CPU  SRAM  EEPROM  Byte and page accessible  Optional memory mapping for direct load and store  I/O Memory  Configuration and Status registers for all peripherals and modules  16 bit-accessible General Purpose Register for global variables or flags  External Memory support  SRAM  SDRAM  Memory mapped external hardware  Bus arbitration  Safe and deterministic handling of CPU and DMA Controller priority  Separate buses for SRAM, EEPROM, I/O Memory and External Memory access  Simultaneous bus access for CPU and DMA Controller  Production Signature Row Memory for factory programmed data  Device ID for each microcontroller device type  Serial number for each device  Oscillator calibration bytes  ADC, DAC and temperature sensor calibration data  User Signature Row  One flash page in size  Can be read and written from software  Content is kept after chip erase 8.2 Overview The Atmel AVR architecture has two main memory spaces, the program memory and the data memory. Executable code can reside only in the program memory, while data can be stored in the program memory and the data memory. The data memory includes the internal SRAM, and EEPROM for nonvolatile data storage. All memory spaces are linear and require no memory bank switching. Nonvolatile memory (NVM) spaces can be locked for further write and read/write operations. This prevents unrestricted access to the application software. A separate memory section contains the fuse bytes. These are used for configuring important system functions, and can only be written by an external programmer.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 13 8067O–AVR–06/2013 The available memory size configurations are shown in “Ordering Information” on page 2. In addition each device has a flash memory signature rows for calibration data, device identification, serial number etc. 8.3 In-System Programmable Flash Program Memory he Atmel AVR XMEGA devices contain on-chip, in-system reprogrammable flash memory for program storage. The flash memory can be accessed for read and write from an external programmer through the PDI or from application software running in the device. All AVR CPU instructions are 16 or 32 bits wide, and each flash location is 16 bits wide. The flash memory is organized in two main sections, the application section and the boot loader section. The sizes of the different sections are fixed, but device-dependent. These two sections have separate lock bits, and can have different levels of protection. The store program memory (SPM) instruction, which is used to write to the flash from the application software, will only operate when executed from the boot loader section. The application section contains an application table section with separate lock settings. This enables safe storage of nonvolatile data in the program memory. Figure 8-1. Flash Program Memory (Hexadecimal address) 8.3.1 Application Section The Application section is the section of the flash that is used for storing the executable application code. The protection level for the application section can be selected by the boot lock bits for this section. The application section can not store any boot loader code since the SPM instruction cannot be executed from the application section. 8.3.2 Application Table Section The application table section is a part of the application section of the flash memory that can be used for storing data. The size is identical to the boot loader section. The protection level for the application table section can be selected by the boot lock bits for this section. The possibilities for different protection levels on the application section and the application table section enable safe parameter storage in the program memory. If this section is not used for data, application code can reside here. 8.3.3 Boot Loader Section While the application section is used for storing the application code, the boot loader software must be located in the boot loader section because the SPM instruction can only initiate programming when executing from this section. The SPM instruction can access the entire flash, including the boot loader section itself. The protection level for the boot loader section can be selected by the boot loader lock bits. If this section is not used for boot loader software, application code can be stored here. Word Address ATxega128A1 ATxmega64A1 0 0 Application Section (Bytes) (128K/64K) ... EFFF / 77FF F000 / 7800 Application Table Section (Bytes) FFFF / 7FFF (8K/4K) 10000 / 8000 Boot Section (Bytes) 10FFF / 87FF (8K/4K)[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 14 8067O–AVR–06/2013 8.3.4 Production Signature Row The production signature row is a separate memory section for factory programmed data. It contains calibration data for functions such as oscillators and analog modules. Some of the calibration values will be automatically loaded to the corresponding module or peripheral unit during reset. Other values must be loaded from the signature row and written to the corresponding peripheral registers from software. For details on calibration conditions, refer to “Electrical Characteristics” on page 76. The production signature row also contains an ID that identifies each microcontroller device type and a serial number for each manufactured device. The serial number consists of the production lot number, wafer number, and wafer coordinates for the device. The device ID for the available devices is shown in Table 8-1. The production signature row cannot be written or erased, but it can be read from application software and external programmers. Table 8-1. Device ID bytes. 8.3.5 User Signature Row The user signature row is a separate memory section that is fully accessible (read and write) from application software and external programmers. It is one flash page in size, and is meant for static user parameter storage, such as calibration data, custom serial number, identification numbers, random number seeds, etc. This section is not erased by chip erase commands that erase the flash, and requires a dedicated erase command. This ensures parameter storage during multiple program/erase operations and on-chip debug sessions. 8.4 Fuses and Lock bits The fuses are used to configure important system functions, and can only be written from an external programmer. The application software can read the fuses. The fuses are used to configure reset sources such as brownout detector and watchdog, startup configuration, JTAG enable, and JTAG user ID. The lock bits are used to set protection levels for the different flash sections (that is, if read and/or write access should be blocked). Lock bits can be written by external programmers and application software, but only to stricter protection levels. Chip erase is the only way to erase the lock bits. To ensure that flash contents are protected even during chip erase, the lock bits are erased after the rest of the flash memory has been erased. An unprogrammed fuse or lock bit will have the value one, while a programmed fuse or lock bit will have the value zero. Both fuses and lock bits are reprogrammable like the flash program memory. 8.5 Data Memory The data memory contains the I/O memory, internal SRAM, optionally memory mapped EEPROM, and external memory if available. The data memory is organized as one continuous memory section, see Figure 8-2 on page 15. To simplify development, I/O Memory, EEPROM and SRAM will always have the same start addresses for all Atmel AVR XMEGA devices. The address space for External Memory will always start at the end of Internal SRAM and end at address 0xFFFFFF. Device Device ID bytes Byte 2 Byte 1 Byte 0 ATxmega64A1 4E 96 1E ATxmega128A1 4C 97 1E[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 15 8067O–AVR–06/2013 Figure 8-2. Data Memory Map (Hexadecimal address) 8.6 EEPROM XMEGA AU devices have EEPROM for nonvolatile data storage. It is either addressable in a separate data space (default) or memory mapped and accessed in normal data space. The EEPROM supports both byte and page access. Memory mapped EEPROM allows highly efficient EEPROM reading and EEPROM buffer loading. When doing this, EEPROM is accessible using load and store instructions. Memory mapped EEPROM will always start at hexadecimal address 0x1000. 8.7 I/O Memory The status and configuration registers for peripherals and modules, including the CPU, are addressable through I/O memory locations. All I/O locations can be accessed by the load (LD/LDS/LDD) and store (ST/STS/STD) instructions, which is used to transfer data between the 32 registers in the register file and the I/O memory. The IN and OUT instructions can address I/O memory locations in the range 0x00 - 0x3F directly. In the address range 0x00 - 0x1F, single- cycle instructions for manipulation and checking of individual bits are available. The I/O memory address for all peripherals and modules in XMEGA A1U is shown in the “Peripheral Module Address Map” on page 62. 8.7.1 General Purpose I/O Registers The lowest 16 I/O memory addresses are reserved as general purpose I/O registers. These registers can be used for storing global variables and flags, as they are directly bit-accessible using the SBI, CBI, SBIS, and SBIC instructions. 8.8 External Memory Four ports can be used for external memory, supporting external SRAM, SDRAM, and memory mapped peripherals such as LCD displays. Refer to “EBI – External Bus Interface” on page 47. The external memory address space will always start at the end of internal SRAM. 8.9 Data Memory and Bus Arbitration Since the data memory is organized as four separate sets of memories, the different bus masters (CPU, DMA controller read and DMA controller write, etc.) can access different memory sections at the same time. Byte Address ATxmega128A1 Byte Address ATxmega64A1 0 I/O Registers (4 KB) 0 I/O Registers FFF FFF (4 KB) 1000 EEPROM (2 KB) 1000 EEPROM 17FF 17FF (2 KB) RESERVED RESERVED 2000 Internal SRAM (8 KB) 2000 Internal SRAM 3FFF 2FFF (4 KB) 4000 External Memory (0 to 16 MB) 3000 External Memory FFFFFF FFFFFF (0 to 16 MB)[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 16 8067O–AVR–06/2013 8.10 Memory Timing Read and write access to the I/O memory takes one CPU clock cycle. A write to SRAM takes one cycle, and a read from SRAM takes two cycles. For burst read (DMA), new data are available every cycle. EEPROM page load (write) takes one cycle, and three cycles are required for read. For burst read, new data are available every second cycle. External memory has multi-cycle read and write. The number of cycles depends on the type of memory and configuration of the external bus interface. Refer to the instruction summary for more details on instructions and instruction timing. 8.11 Device ID and Revision Each device has a three-byte device ID. This ID identifies Atmel as the manufacturer of the device and the device type. A separate register contains the revision number of the device. 8.12 I/O Memory Protection Some features in the device are regarded as critical for safety in some applications. Due to this, it is possible to lock the I/O register related to the clock system, the event system, and the advanced waveform extensions. As long as the lock is enabled, all related I/O registers are locked and they can not be written from the application software. The lock registers themselves are protected by the configuration change protection mechanism. 8.13 JTAG Disable It is possible to disable the JTAG interface from the application software. This will prevent all external JTAG access to the device until the next device reset or until JTAG is enabled again from the application software. As long as JTAG is disabled, the I/O pins required for JTAG can be used as normal I/O pins. 8.14 Flash and EEPROM Page Size The flash program memory and EEPROM data memory are organized in pages. The pages are word accessible for the flash and byte accessible for the EEPROM. Table 8-2 shows the Flash Program Memory organization. Flash write and erase operations are performed on one page at a time, while reading the Flash is done one byte at a time. For Flash access the Z-pointer (Z[m:n]) is used for addressing. The most significant bits in the address (FPAGE) gives the page number and the least significant address bits (FWORD) gives the word in the page. Table 8-2. Number of words and Pages in the Flash. Table 8-3 shows EEPROM memory organization for the Atmel AVR XMEGA A1U devices. EEPROM write and erase operations can be performed one page or one byte at a time, while reading the EEPROM is done one byte at a time. For EEPROM access the NVM Address Register (ADDR[m:n]) is used for addressing. The most significant bits in the address (E2PAGE) give the page number and the least significant address bits (E2BYTE) give the byte in the page. Device PC size Flash Page Size FWORD FPAGE Application Boot bits bytes words Size No of pages Size No of pages ATxmega64A1 16 64K + 4K 128 Z[7:1] Z[16:8] 64K 256 4K 16 ATxmega128A1 17 128K+ 8K 256 Z[8:1] Z[17:9] 128K 256 8K 16[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 17 8067O–AVR–06/2013 Table 8-3. Number of Bytes and Pages in the EEPROM. 8.14.1 I/O Memory All peripherals and modules are addressable through I/O memory locations in the data memory space. All I/O memory locations can be accessed by the Load (LD/LDS/LDD) and Store (ST/STS/STD) instructions, transferring data between the 32 general purpose registers in the CPU and the I/O Memory. The IN and OUT instructions can address I/O memory locations in the range 0x00 - 0x3F directly. I/O registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. The value of single bits can be checked by using the SBIS and SBIC instructions on these registers. The I/O memory address for all peripherals and modules in XMEGA A1 is shown in the “Peripheral Module Address Map” on page 62. Device EEPROM Page Size E2BYTE E2PAGE No of pages Size bytes ATxmega64A1 2 KB 32 ADDR[4:0] ADDR[10:5] 64 ATxmega128A1 2 KB 32 ADDR[4:0 ADDR[10:5] 64[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 18 8067O–AVR–06/2013 9. DMAC - Direct Memory Access Controller 9.1 Features  Allows High-speed data transfer  From memory to peripheral  From memory to memory  From peripheral to memory  From peripheral to peripheral  4 Channels  From 1 byte and up to 16M bytes transfers in a single transaction  Multiple addressing modes for source and destination address  Increment  Decrement  Static  1, 2, 4, or 8 byte Burst Transfers  Programmable priority between channels 9.2 Overview The four-channel direct memory access (DMA) controller can transfer data between memories and peripherals, and thus offload these tasks from the CPU. It enables high data transfer rates with minimum CPU intervention, and frees up CPU time. The four DMA channels enable up to four independent and parallel transfers. The DMA controller can move data between SRAM and peripherals, between SRAM locations and directly between peripheral registers. With access to all peripherals, the DMA controller can handle automatic transfer of data to/from communication modules. The DMA controller can also read from memory mapped EEPROM. Data transfers are done in continuous bursts of 1, 2, 4, or 8 bytes. They build block transfers of configurable size from 1 byte to 64KB. A repeat counter can be used to repeat each block transfer for single transactions up to 16MB. Source and destination addressing can be static, incremental or decremental. Automatic reload of source and/or destination addresses can be done after each burst or block transfer, or when a transaction is complete. Application software, peripherals, and events can trigger DMA transfers. The four DMA channels have individual configuration and control settings. This include source, destination, transfer triggers, and transaction sizes. They have individual interrupt settings. Interrupt requests can be generated when a transaction is complete or when the DMA controller detects an error on a DMA channel. To allow for continuous transfers, two channels can be interlinked so that the second takes over the transfer when the first is finished, and vice versa.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 19 8067O–AVR–06/2013 10. Event System 10.1 Features  Inter-peripheral communication and signalling with minimum latency  CPU and DMA independent operation  8 Event Channels allows for up to 8 signals to be routed at the same time  Events can be generated by  Timer/Counters (TCxn)  Real Time Counter (RTC)  Analog to Digital Converters (ADCx)  Analog Comparators (ACx)  Ports (PORTx)  System Clock (ClkSYS)  Software (CPU)  Events can be used by  Timer/Counters (TCxn)  Analog to Digital Converters (ADCx)  Digital to Analog Converters (DACx)  Ports (PORTx)  DMA Controller (DMAC)  IR Communication Module (IRCOM)  The same event can be used by multiple peripherals for synchronized timing  Advanced Features  Manual Event Generation from software (CPU)  Quadrature Decoding  Digital Filtering  Functions in Active and Idle mode 10.2 Overview The Event System is a set of features for inter-peripheral communication. It enables the possibility for a change of state in one peripheral to automatically trigger actions in one or more peripherals. These changes in a peripheral that will trigger actions in other peripherals are configurable by software. It is a simple, but powerful system as it allows for autonomous control of peripherals without any use of interrupts, CPU or DMA resources. The indication of a change in a peripheral is referred to as an event, and is usually the same as the interrupt conditions for that peripheral. Events are passed between peripherals using a dedicated routing network called the Event Routing Network. Figure 10-1 on page 20 shows a basic block diagram of the Event System with the Event Routing Network and the peripherals to which it is connected. This highly flexible system can be used for simple routing of signals, pin functions or for sequencing of events. The maximum latency is two CPU clock cycles from when an event is generated in one peripheral, until the actions are triggered in one or more other peripherals. The Event System is functional in both Active and Idle modes.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 20 8067O–AVR–06/2013 Figure 10-1. Event system block diagram. he event routing network consists of eight software-configurable multiplexers that control how events are routed and used. These are called event channels, and allow for up to eight parallel event routing configurations. The maximum routing latency is two peripheral clock cycles. The event system works in both active mode and idle sleep mode. DAC Timer / Counters ADC Real Time Counter Port pins CPU / Software DMA Controller IRCOM Event Routing Network Event System Controller clkPER Prescaler AC[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 21 8067O–AVR–06/2013 11. System Clock and Clock options 11.1 Features  Fast start-up time  Safe run-time clock switching  Internal Oscillators:  32 MHz run-time calibrated RC oscillator  2 MHz run-time calibrated RC oscillator  32.768 kHz calibrated RC oscillator  32 kHz Ultra Low Power (ULP) oscillator with 1 kHz ouput  External clock options  0.4 - 16 MHz Crystal Oscillator  32 kHz Crystal Oscillator  External clock  PLL with internal and external clock options with 1 to 31x multiplication  Clock Prescalers with 1x to 2048x division  Fast peripheral clock running at two and four times the CPU clock speed  Automatic Run-Time Calibration of internal oscillators  Crystal Oscillator failure detection 11.2 Overview Atmel AVR XMEGA devices have a flexible clock system supporting a large number of clock sources. It incorporates both accurate internal oscillators and external crystal oscillator and resonator support. A high-frequency phase locked loop (PLL) and clock prescalers can be used to generate a wide range of clock frequencies. An oscillator failure monitor can be enabled to issue a non-maskable interrupt and switch to the internal oscillator if the external oscillator or PLL fails. When a reset occurs, all clock sources except the 32kHz ultra low power oscillator are disabled. After reset, the device will always start up running from the 2MHz internal oscillator. During normal operation, the system clock source and prescalers can be changed from software at any time. Figure 11-1 on page 22 presents the principal clock system in the XMEGA A1U family devices. Not all of the clocks need to be active at a given time. The clocks for the CPU and peripherals can be stopped using sleep modes and power reduction registers as described in “Power Management and Sleep Modes” on page 24.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 22 8067O–AVR–06/2013 Figure 11-1. The clock system, clock sources and clock distribution 11.3 Clock Options The clock sources are divided in two main groups: internal oscillators and external clock sources. Most of the clock sources can be directly enabled and disabled from software, while others are automatically enabled or disabled, depending on peripheral settings. After reset, the device starts up running from the 2MHz internal oscillator. The other clock sources and PLL are turned off by default. The internal oscillators do not require any external components to run. For details on characteristics and accuracy of the internal oscillators, refer to the device datasheet. 11.3.1 32 kHz Ultra Low Power Internal Oscillator This oscillator provides an approximate 32kHz clock. The 32kHz ultra low power (ULP) internal oscillator is a very low power clock source, and it is not designed for high accuracy. The oscillator employs a built-in prescaler that provides a 1kHz output. The oscillator is automatically enabled/disabled when it is used as clock source for any part of the device. This oscillator can be selected as the clock source for the RTC. Real Time Counter Peripherals RAM AVR CPU Non-Volatile Memory Watchdog Timer Brown-out Detector System Clock Prescalers System Clock Multiplexer (SCLKSEL) PLLSRC RTCSRC DIV32 32 kHz Int. ULP 32.768 kHz Int. OSC 32.768 kHz TOSC 2 MHz Int. Osc 32 MHz Int. Osc 0.4 – 16 MHz XTAL DIV32 DIV32 DIV4 XOSCSEL PLL TOSC1 TOSC2 XTAL1 XTAL2 clkSYS clkRTC clkPER2 clkPER clkCPU clkPER4[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 23 8067O–AVR–06/2013 11.3.2 32.768 kHz Calibrated Internal Oscillator This oscillator provides an approximate 32.768kHz clock. It is calibrated during production to provide a default frequency close to its nominal frequency. The calibration register can also be written from software for run-time calibration of the oscillator frequency. The oscillator employs a built-in prescaler, which provides both a 32.768kHz output and a 1.024kHz output. 11.3.3 32.768 kHz Crystal Oscillator A 32.768kHz crystal oscillator can be connected between the 1 and 2 pins and enables a dedicated low frequency oscillator input circuit. A low power mode with reduced voltage swing on 2 is available. This oscillator can be used as a clock source for the system clock and RTC. 11.3.4 0.4 - 16 MHz Crystal Oscillator This oscillator can operate in four different modes optimized for different frequency ranges, all within 0.4 - 16MHz. 11.3.5 2 MHz Run-time Calibrated Internal Oscillator The 2MHz Run-time Calibrated Internal Oscillator is a high frequency oscillator. It is calibrated during production to provide a default frequency which is close to its nominal frequency. The oscillator can use the 32kHz Calibrated Internal Oscillator or the 32kHz Crystal Oscillator as a source for calibrating the frequency run-time to compensate for temperature and voltage drift hereby optimizing the accuracy of the oscillator. 11.3.6 32 MHz Run-time Calibrated Internal Oscillator The 32MHz Run-time Calibrated Internal Oscillator is a high frequency oscillator. It is calibrated during production to provide a default frequency which is close to its nominal frequency. The oscillator can use the 32kHz Calibrated Internal Oscillator or the 32kHz Crystal Oscillator as a source for calibrating the frequency run-time to compensate for temperature and voltage drift hereby optimizing the accuracy of the oscillator. 11.3.7 External Clock input The XTAL1 and XTAL2 pins can be used to drive an external oscillator, either a quartz crystal or a ceramic resonator. XTAL1 can be used as input for an external clock signal. The 1 and 2 pins is dedicated to driving a 32.768kHz crystal oscillator. 11.3.8 PLL with Multiplication factor 1 - 31x The built-in phase locked loop (PLL) can be used to generate a high-frequency system clock. The PLL has a userselectable multiplication factor of from 1 to 31. In combination with the prescalers, this gives a wide range of output frequencies from all clock sources.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 24 8067O–AVR–06/2013 12. Power Management and Sleep Modes 12.1 Features  Power management for adjusting power consumption and functions  5 sleep modes  Idle  Power-down  Power-save  Standby  Extended standby  Power reduction register to disable clock and turn off unused peripherals in active and idle modes 12.2 Overview Various sleep modes and clock gating are provided in order to tailor power consumption to application requirements. This enables the Atmel AVR XMEGA microcontroller to stop unused modules to save power. All sleep modes are available and can be entered from active mode. In active mode, the CPU is executing application code. When the device enters sleep mode, program execution is stopped and interrupts or a reset is used to wake the device again. The application code decides which sleep mode to enter and when. Interrupts from enabled peripherals and all enabled reset sources can restore the microcontroller from sleep to active mode. In addition, power reduction registers provide a method to stop the clock to individual peripherals from software. When this is done, the current state of the peripheral is frozen, and there is no power consumption from that peripheral. This reduces the power consumption in active mode and idle sleep modes and enables much more fine-tuned power management than sleep modes alone. 12.3 Sleep Modes Sleep modes are used to shut down modules and clock domains in the microcontroller in order to save power. XMEGA microcontrollers have five different sleep modes tuned to match the typical functional stages during application execution. A dedicated sleep instruction (SLEEP) is available to enter sleep mode. Interrupts are used to wake the device from sleep, and the available interrupt wake-up sources are dependent on the configured sleep mode. When an enabled interrupt occurs, the device will wake up and execute the interrupt service routine before continuing normal program execution from the first instruction after the SLEEP instruction. If other, higher priority interrupts are pending when the wake-up occurs, their interrupt service routines will be executed according to their priority before the interrupt service routine for the wake-up interrupt is executed. After wake-up, the CPU is halted for four cycles before execution starts. The content of the register file, SRAM and registers are kept during sleep. If a reset occurs during sleep, the device will reset, start up, and execute from the reset vector. 12.3.1 Idle Mode In idle mode the CPU and nonvolatile memory are stopped (note that any ongoing programming will be completed), but all peripherals, including the interrupt controller, event system and DMA controller are kept running. Any enabled interrupt will wake the device. 12.3.2 Power-down Mode In power-down mode, all clocks, including the real-time counter clock source, are stopped. This allows operation only of asynchronous modules that do not require a running clock. The only interrupts that can wake up the MCU are the twowire interface address match interrupt and asynchronous port interrupts, e.g pin change.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 25 8067O–AVR–06/2013 12.3.3 Power-save Mode Power-save mode is identical to power down, with one exception. If the real-time counter (RTC) is enabled, it will keep running during sleep, and the device can also wake up from either an RTC overflow or compare match interrupt. 12.3.4 Standby Mode Standby mode is identical to power down, with the exception that the enabled system clock sources are kept running while the CPU, peripheral, and RTC clocks are stopped. This reduces the wake-up time. 12.3.5 Extended Standby Mode Extended standby mode is identical to power-save mode, with the exception that the enabled system clock sources are kept running while the CPU and peripheral clocks are stopped. This reduces the wake-up time.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 26 8067O–AVR–06/2013 13. System Control and Reset 13.1 Features  Multiple reset sources for safe operation and device reset  Power-On Reset  External Reset  Watchdog Reset  Brown-Out Reset  PDI reset  Software reset  Asynchronous reset  No running clock in the device is required for reset  Reset status register 13.2 Overview The reset system issues a microcontroller reset and sets the device to its initial state. This is for situations where operation should not start or continue, such as when the microcontroller operates below its power supply rating. If a reset source goes active, the device enters and is kept in reset until all reset sources have released their reset. The I/O pins are immediately tri-stated. The program counter is set to the reset vector location, and all I/O registers are set to their initial values. The SRAM content is kept. However, if the device accesses the SRAM when a reset occurs, the content of the accessed location can not be guaranteed. After reset is released from all reset sources, the default oscillator is started and calibrated before the device starts running from the reset vector address. By default, this is the lowest program memory address, 0, but it is possible to move the reset vector to the lowest address in the boot section. The reset functionality is asynchronous, and so no running system clock is required to reset the device. The software reset feature makes it possible to issue a controlled system reset from the user software. The reset status register has individual status flags for each reset source. It is cleared at power-on reset, and shows which sources have issued a reset since the last power-on. 13.3 Reset Sequence A reset request from any reset source will immediately reset the device and keep it in reset as long as the request is active. When all reset requests are released, the device will go through three stages before the device starts running again:  Reset counter delay  Oscillator startup  Oscillator calibration If another reset requests occurs during this process, the reset sequence will start over again. 13.4 Reset Sources 13.4.1 Power-On Reset TA power-on reset (POR) is generated by an on-chip detection circuit. The POR is activated when the VCC rises and reaches the POR threshold voltage (VPOT), and this will start the reset sequence. The POR is also activated to power down the device properly when the VCC falls and drops below the VPOT level. The VPOT level is higher for falling VCC than for rising VCC. Consult the datasheet for POR characteristics data.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 27 8067O–AVR–06/2013 13.4.2 Brownout Detection The on-chip brownout detection (BOD) circuit monitors the VCC level during operation by comparing it to a fixed, programmable level that is selected by the BODLEVEL fuses. If disabled, BOD is forced on at the lowest level during chip erase and when the PDI is enabled. 13.4.3 External Reset The external reset circuit is connected to the external RESET pin. The external reset will trigger when the RESET pin is driven below the RESET pin threshold voltage, VRST, for longer than the minimum pulse period, tEXT. The reset will be held as long as the pin is kept low. The RESET pin includes an internal pull-up resistor. 13.4.4 Watchdog Reset The watchdog timer (WDT) is a system function for monitoring correct program operation. If the WDT is not reset from the software within a programmable timeout period, a watchdog reset will be given. The watchdog reset is active for one to two clock cycles of the 2MHz internal oscillator. For more details see “WDT - Watchdog Timer” on page 28. 13.4.5 Software reset The software reset makes it possible to issue a system reset from software by writing to the software reset bit in the reset control register.The reset will be issued within two CPU clock cycles after writing the bit. It is not possible to execute any instruction from when a software reset is requested until it is issued. 13.4.6 Program and Debug Interface Reset The program and debug interface reset contains a separate reset source that is used to reset the device during external programming and debugging. This reset source is accessible only from external debuggers and programmers.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 28 8067O–AVR–06/2013 13.5 WDT - Watchdog Timer 13.5.1 Features  Issues a device reset if the timer is not reset before its timeout period  Asynchronous operation from dedicated oscillator  1kHz output of the 32kHz ultra low power oscillator  11 selectable timeout periods, from 8ms to 8s  Two operation modes:  Normal mode  Window mode  Configuration lock to prevent unwanted changes 13.6 Overview The watchdog timer (WDT) is a system function for monitoring correct program operation. It makes it possible to recover from error situations such as runaway or deadlocked code. The WDT is a timer, configured to a predefined timeout period, and is constantly running when enabled. If the WDT is not reset within the timeout period, it will issue a microcontroller reset. The WDT is reset by executing the WDR (watchdog timer reset) instruction from the application code. The window mode makes it possible to define a time slot or window inside the total timeout period during which WDT must be reset. If the WDT is reset outside this window, either too early or too late, a system reset will be issued. Compared to the normal mode, this can also catch situations where a code error causes constant WDR execution. The WDT will run in active mode and all sleep modes, if enabled. It is asynchronous, runs from a CPU-independent clock source, and will continue to operate to issue a system reset even if the main clocks fail. The configuration change protection mechanism ensures that the WDT settings cannot be changed by accident. For increased safety, a fuse for locking the WDT settings is also available.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 29 8067O–AVR–06/2013 14. Interrupts and Programmable Multilevel Interrupt Controller 14.1 Features  Short and predictable interrupt response time  Separate interrupt configuration and vector address for each interrupt  Programmable multilevel interrupt controller  Interrupt prioritizing according to level and vector address  Three selectable interrupt levels for all interrupts: low, medium and high  Selectable, round-robin priority scheme within low-level interrupts  Non-maskable interrupts for critical functions  Interrupt vectors optionally placed in the application section or the boot loader section 14.2 Overview Interrupts signal a change of state in peripherals, and this can be used to alter program execution. Peripherals can have one or more interrupts, and all are individually enabled and configured. When an interrupt is enabled and configured, it will generate an interrupt request when the interrupt condition is present. The programmable multilevel interrupt controller (PMIC) controls the handling and prioritizing of interrupt requests. When an interrupt request is acknowledged by the PMIC, the program counter is set to point to the interrupt vector, and the interrupt handler can be executed. All peripherals can select between three different priority levels for their interrupts: low, medium, and high. Interrupts are prioritized according to their level and their interrupt vector address. Medium-level interrupts will interrupt low-level interrupt handlers. High-level interrupts will interrupt both medium- and low-level interrupt handlers. Within each level, the interrupt priority is decided from the interrupt vector address, where the lowest interrupt vector address has the highest interrupt priority. Low-level interrupts have an optional round-robin scheduling scheme to ensure that all interrupts are serviced within a certain amount of time. Non-maskable interrupts (NMI) are also supported, and can be used for system critical functions. 14.3 Interrupt vectors The interrupt vector is the sum of the peripheral’s base interrupt address and the offset address for specific interrupts in each peripheral. The base addresses for the Atmel AVR XMEGA A1U devices are shown in Table 14-1. Offset addresses for each interrupt available in the peripheral are described for each peripheral in the XMEGA AU manual. For peripherals or modules that have only one interrupt, the interrupt vector is shown in Table 14-1. The program address is the word address. Table 14-1. Reset and Interrupt vectors Program Address (Base Address) Source Interrupt Description 0x000 RESET 0x002 OSCF_INT_vect Crystal Oscillator Failure Interrupt vector (NMI) 0x004 PORTC_INT_base Port C Interrupt base 0x008 PORTR_INT_base Port R Interrupt base 0x00C DMA_INT_base DMA Controller Interrupt base 0x014 RTC_INT_base Real Time Counter Interrupt base 0x018 TWIC_INT_base Two-Wire Interface on Port C Interrupt base[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 30 8067O–AVR–06/2013 0x01C TCC0_INT_base Timer/Counter 0 on port C Interrupt base 0x028 TCC1_INT_base Timer/Counter 1 on port C Interrupt base 0x030 SPIC_INT_vect SPI on port C Interrupt vector 0x032 USARTC0_INT_base USART 0 on port C Interrupt base 0x038 USARTC1_INT_base USART 1 on port C Interrupt base 0x03E AES_INT_vect AES Interrupt vector 0x040 NVM_INT_base Non-Volatile Memory Interrupt base 0x044 PORTB_INT_base Port B Interrupt base 0x048 ACB_INT_base Analog Comparator on Port B Interrupt base 0x04E ADCB_INT_base Analog to Digital Converter on Port B Interrupt base 0x056 PORTE_INT_base Port E Interrupt base 0x05A TWIE_INT_base Two-Wire Interface on Port E Interrupt base 0x05E TCE0_INT_base Timer/Counter 0 on port E Interrupt base 0x06A TCE1_INT_base Timer/Counter 1 on port E Interrupt base 0x072 SPIE_INT_vect SPI on port E Interrupt vector 0x074 USARTE0_INT_base USART 0 on port E Interrupt base 0x07A USARTE1_INT_base USART 1 on port E Interrupt base 0x080 PORTD_INT_base Port D Interrupt base 0x084 PORTA_INT_base Port A Interrupt base 0x088 ACA_INT_base Analog Comparator on Port A Interrupt base 0x08E ADCA_INT_base Analog to Digital Converter on Port A Interrupt base 0x096 TWID_INT_base Two-Wire Interface on Port D Interrupt base 0x09A TCD0_INT_base Timer/Counter 0 on port D Interrupt base 0x0A6 TCD1_INT_base Timer/Counter 1 on port D Interrupt base 0x0AE SPID_INT_vector SPI on port D Interrupt vector 0x0B0 USARTD0_INT_base USART 0 on port D Interrupt base 0x0B6 USARTD1_INT_base USART 1 on port D Interrupt base 0x0BC PORTQ_INT_base Port Q INT base 0x0C0 PORTH_INT_base Port H INT base 0x0C4 PORTJ_INT_base Port J INT base 0x0C8 PORTK_INT_base Port K INT base 0x0D0 PORTF_INT_base Port F INT base 0x0D4 TWIF_INT_base Two-Wire Interface on Port F INT base Program Address (Base Address) Source Interrupt Description[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 31 8067O–AVR–06/2013 0x0D8 TCF0_INT_base Timer/Counter 0 on port F Interrupt base 0x0E4 TCF1_INT_base Timer/Counter 1 on port F Interrupt base 0x0EC SPIF_INT_vector SPI ion port F Interrupt base 0x0EE USARTF0_INT_base USART 0 on port F Interrupt base 0x0F4 USARTF1_INT_base USART 1 on port F Interrupt base Program Address (Base Address) Source Interrupt Description[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 32 8067O–AVR–06/2013 15. I/O Ports 15.1 Features  78 General purpose input and output pins with individual configuration  Output driver with configurable driver and pull settings:  Totem-pole  Wired-AND  Wired-OR  Bus-keeper  Inverted I/O  Input with synchronous and/or asynchronous sensing with interrupts and events  Sense both edges  Sense rising edges  Sense falling edges  Sense low level  Optional pull-up and pull-down resistor on input and Wired-OR/AND configurations  Optional slew rate control  Asynchronous pin change sensing that can wake the device from all sleep modes  Two port interrupts with pin masking per I/O port  Efficient and safe access to port pins  Hardware read-modify-write through dedicated toggle/clear/set registers  Configuration of multiple pins in a single operation  Mapping of port registers into bit-accessible I/O memory space  Peripheral clocks output on port pin  Real-time counter clock output to port pin  Event channels can be output on port pin  Remapping of digital peripheral pin functions  Selectable USART, SPI, and timer/counter input/output pin locations 15.2 Overview One port consists of up to eight port pins: pin 0 to 7. Each port pin can be configured as input or output with configurable driver and pull settings. They also implement synchronous and asynchronous input sensing with interrupts and events for selectable pin change conditions. Asynchronous pin-change sensing means that a pin change can wake the device from all sleep modes, included the modes where no clocks are running. All functions are individual and configurable per pin, but several pins can be configured in a single operation. The pins have hardware read-modify-write (RMW) functionality for safe and correct change of drive value and/or pull resistor configuration. The direction of one port pin can be changed without unintentionally changing the direction of any other pin. The port pin configuration also controls input and output selection of other device functions. It is possible to have both the peripheral clock and the real-time clock output to a port pin, and available for external use. The same applies to events from the event system that can be used to synchronize and control external functions. Other digital peripherals, such as USART, SPI, and timer/counters, can be remapped to selectable pin locations in order to optimize pin-out versus application needs. The notation of these ports are PORTA, PORTB, PORTC, PORTD, PORTE, PORTF, PORTH, PORTJ, PORTK, PORTQ and PORTR.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 33 8067O–AVR–06/2013 15.3 Output Driver All port pins (Pn) have programmable output configuration. The port pins also have configurable slew rate limitation to reduce electromagnetic emission. 15.3.1 Push-pull Figure 15-1. I/O configuration - Totem-pole 15.3.2 Pull-down Figure 15-2. I/O configuration - Totem-pole with pull-down (on input) 15.3.3 Pull-up Figure 15-3. I/O configuration - Totem-pole with pull-up (on input) INn OUTn DIRn Pn INn OUTn DIRn Pn INn OUTn DIRn Pn[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 34 8067O–AVR–06/2013 15.3.4 Bus-keeper The bus-keeper’s weak output produces the same logical level as the last output level. It acts as a pull-up if the last level was ‘1’, and pull-down if the last level was ‘0’. Figure 15-4. I/O configuration - Totem-pole with bus-keeper 15.3.5 Others Figure 15-5. Output configuration - Wired-OR with optional pull-down Figure 15-6. I/O configuration - Wired-AND with optional pull-up INn OUTn DIRn Pn INn OUTn Pn INn OUTn Pn[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 35 8067O–AVR–06/2013 15.4 Input sensing Input sensing is synchronous or asynchronous depending on the enabled clock for the ports, and the configuration is shown in Figure 15-7 on page 35. Figure 15-7. Input sensing system overview When a pin is configured with inverted I/O the pin value is inverted before the input sensing. 15.5 Port Interrupt Each ports have two interrupts with seperate priority and interrupt vector. All pins on the port can be individually selected as source for each of the interrupts. The interrupts are then triggered according to the input sense configuration for each pin configured as source for the interrupt. 15.6 Alternate Port Functions In addition to the input/output functions on all port pins, most pins have alternate functions. This means that other modules or peripherals connected to the port can use the port pins for their functions, such as communication or pulsewidth modulation. “Pinout and Pin Functions” on page 55 shows which modules on peripherals that enables alternate functions on a pin, and what alternate functions that is available on a pin. INVERTED I/O Interrupt Control IREQ Event Pn D Q R D Q R Synchronizer INn EDGE DETECT Asynchronous sensing Synchronous sensing EDGE DETECT[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 36 8067O–AVR–06/2013 16. T/C - 16-bit Timer/Counter 16.1 Features  Eight 16-bit Timer/Counters  Four Timer/Counters of type 0  Four Timer/Counters of type 1  Four Compare or Capture (CC) Channels in Timer/Counter 0  Two Compare or Capture (CC) Channels in Timer/Counter 1  Double Buffered Timer Period Setting  Double Buffered Compare or Capture Channels  Waveform Generation:  Single Slope Pulse Width Modulation  Dual Slope Pulse Width Modulation  Frequency Generation  Input Capture:  Input Capture with Noise Cancelling  Frequency capture  Pulse width capture  32-bit input capture  Event Counter with Direction Control  Timer Overflow and Timer Error Interrupts and Events  One Compare Match or Capture Interrupt and Event per CC Channel  Supports DMA Operation  Hi-Resolution Extension (Hi-Res)  Advanced Waveform Extension (AWEX) 16.2 Overview Atmel AVR XMEGA devices have a set of eight flexible 16-bit timer/counters (TC). Their capabilities include accurate program execution timing, frequency and waveform generation, and input capture with time and frequency measurement of digital signals. Two timer/counters can be cascaded to create a 32-bit timer/counter with optional 32-bit capture. A timer/counter consists of a base counter and a set of compare or capture (CC) channels. The base counter can be used to count clock cycles or events. It has direction control and period setting that can be used for timing. The CC channels can be used together with the base counter to do compare match control, frequency generation, and pulse width waveform modulation, as well as various input capture operations. A timer/counter can be configured for either capture or compare functions, but cannot perform both at the same time. A timer/counter can be clocked and timed from the peripheral clock with optional prescaling or from the event system. The event system can also be used for direction control and capture trigger or to synchronize operations. There are two differences between timer/counter type 0 and type 1. Timer/counter 0 has four CC channels, and timer/counter 1 has two CC channels. All information related to CC channels 3 and 4 is valid only for timer/counter 0. Only Timer/Counter 0 has the split mode feature that split it into 2 8-bit Timer/Counters with four compare channels each. Some timer/counters have extensions to enable more specialized waveform and frequency generation. The advanced waveform extension (AWeX) is intended for motor control and other power control applications. It enables low- and highside output with dead-time insertion, as well as fault protection for disabling and shutting down external drivers. It can also generate a synchronized bit pattern across the port pins. The advanced waveform extension can be enabled to provide extra and more advanced features for the Timer/Counter. This is only available for Timer/Counter 0. See “AWeX - Advanced Waveform Extension” on page 38 for more details.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 37 8067O–AVR–06/2013 The high-resolution (hi-res) extension can be used to increase the waveform output resolution by four or eight times by using an internal clock source running up to four times faster than the peripheral clock. See “Hi-Res - High Resolution Extension” on page 39 for more details. Figure 16-1. Overview of a Timer/Counter and closely related peripherals PORTC, PORTD, PORTE and PORTF each has one Timer/Counter 0 and one Timer/Counter1. Notation of these Timer/Counters are TCC0 (Time/Counter C0), TCC1, TCD0, TCD1, TCE0, TCE1, TCF0, and TCF1, respectively. AWeX Compare/Capture Channel D Compare/Capture Channel C Compare/Capture Channel B Compare/Capture Channel A Waveform Generation Buffer Comparator Hi-Res Fault Protection Capture Control Base Counter Counter Control Logic Timer Period Prescaler DTI Dead-Time Insertion Pattern Generation clkPER4 PORT Event System clkPER Timer/Counter[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 38 8067O–AVR–06/2013 17. AWeX - Advanced Waveform Extension 17.1 Features  Output with complementary output from each Capture channel  Four Dead Time Insertion (DTI) Units, one for each Capture channel  8-bit DTI Resolution  Separate High and Low Side Dead-Time Setting  Double Buffered Dead-Time  Event Controlled Fault Protection  Single Channel Multiple Output Operation (for BLDC motor control)  Double Buffered Pattern Generation 17.2 Overview The advanced waveform extension (AWeX) provides extra functions to the timer/counter in waveform generation (WG) modes. It is primarily intended for use with different types of motor control and other power control applications. It enables low- and high side output with dead-time insertion and fault protection for disabling and shutting down external drivers. It can also generate a synchronized bit pattern across the port pins. Each of the waveform generator outputs from the Timer/Counter 0 are split into a complimentary pair of outputs when any AWeX features are enabled. These output pairs go through a dead-time insertion (DTI) unit that generates the noninverted low side (LS) and inverted high side (HS) of the WG output with dead-time insertion between LS and HS switching. The DTI output will override the normal port value according to the port override setting. The pattern generation unit can be used to generate a synchronized bit pattern on the port it is connected to. In addition, the WG output from compare channel A can be distributed to and override all the port pins. When the pattern generator unit is enabled, the DTI unit is bypassed. The fault protection unit is connected to the event system, enabling any event to trigger a fault condition that will disable the AWeX output. The event system ensures predictable and instant fault reaction, and gives great flexibility in the selection of fault triggers. The AWeX is available for TCC0 and TCE0. The notation of these are AWEXC and AWEXE.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 39 8067O–AVR–06/2013 18. Hi-Res - High Resolution Extension 18.1 Features  Increases Waveform Generator resolution by 2-bits (4x)  Supports Frequency, single- and dual-slope PWM operation  Supports the AWeX when this is enabled and used for the same Timer/Counter 18.2 Overview TThe high-resolution (hi-res) extension can be used to increase the resolution of the waveform generation output from a timer/counter by four or eight. It can be used for a timer/counter doing frequency, single-slope PWM, or dual-slope PWM generation. It can also be used with the AWeX if this is used for the same timer/counter. The hi-res extension uses the peripheral 4x clock (ClkPER4). The system clock prescalers must be configured so the peripheral 4x clock frequency is four times higher than the peripheral and CPU clock frequency when the hi-res extension is enabled. There are four hi-res extensions that each can be enabled for each timer/counters pair on PORTC, PORTD, PORTE and PORTF. The notation of these peripherals are HIRESC, HIRESD, HIRESE and HIRESF, respectively.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 40 8067O–AVR–06/2013 19. RTC - 16-bit Real-Time Counter 19.1 Features  16-bit resolution  Selectable clock source  32.768kHz external crystal  External clock  32.768kHz internal oscillator  32kHz internal ULP oscillator  Programmable 10-bit clock prescaling  One compare register  One period register  Clear counter on period overflow  Optional interrupt/event on overflow and compare match 19.2 Overview The 16-bit real-time counter (RTC) is a counter that typically runs continuously, including in low-power sleep modes, to keep track of time. It can wake up the device from sleep modes and/or interrupt the device at regular intervals. The reference clock is typically the 1.024kHz output from a high-accuracy crystal of 32.768kHz, and this is the configuration most optimized for low power consumption. The faster 32.768kHz output can be selected if the RTC needs a resolution higher than 1ms. The RTC can also be clocked from an external clock signal, the 32.768kHz internal oscillator or the 32kHz internal ULP oscillator. The RTC includes a 10-bit programmable prescaler that can scale down the reference clock before it reaches the counter. A wide range of resolutions and time-out periods can be configured. With a 32.768kHz clock source, the maximum resolution is 30.5µs, and time-out periods can range up to 2000 seconds. With a resolution of 1s, the maximum timeout period is more than18 hours (65536 seconds). The RTC can give a compare interrupt and/or event when the counter equals the compare register value, and an overflow interrupt and/or event when it equals the period register value. Figure 19-1. Real Time Counter overview 32.768kHz Crystal Osc 32.768kHz Int. Osc TOSC1 TOSC2 External Clock DIV32 DIV32 32kHz int ULP (DIV32) RTCSRC 10-bit prescaler clkRTC CNT PER COMP = = ”match”/ Compare TOP/ Overflow[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 41 8067O–AVR–06/2013 20. TWI - Two-Wire Interface 20.1 Features  Four identical two-wire interface peripherals  Bidirectional two-wire communication interface  Phillips I2C compatible  System Management Bus (SMBus) compatible  Bus master and slave operation supported  Slave operation  Single bus master operation  Bus master in multi-master bus environment  Multi-master arbitration  Flexible slave address match functions  7-bit and general call address recognition in hardware  10-bit addressing supported  Address mask register for dual address match or address range masking  Optional software address recognition for unlimited number of addresses  Slave can operate in all sleep modes, including power-down  Slave address match can wake device from all sleep modes, including power-down  100kHz and 400kHz bus frequency support  Slew-rate limited output drivers  Input filter for bus noise and spike suppression  Support arbitration between start repeated start and data bit (SMBus)  Slave arbitration allows support for address resolve protocol (ARP) (SMBus) 20.2 Overview The two-wire interface (TWI) is a bidirectional, two-wire communication interface. It is I2C and System Management Bus (SMBus) compatible. The only external hardware needed to implement the bus is one pull-up resistor on each bus line. A device connected to the bus must act as a master or a slave. The master initiates a data transaction by addressing a slave on the bus and telling whether it wants to transmit or receive data. One bus can have many slaves and one or several masters that can take control of the bus. An arbitration process handles priority if more than one master tries to transmit data at the same time. Mechanisms for resolving bus contention are inherent in the protocol. The TWI module supports master and slave functionality. The master and slave functionality are separated from each other, and can be enabled and configured separately. The master module supports multi-master bus operation and arbitration. It contains the baud rate generator. Both 100kHz and 400kHz bus frequency is supported. Quick command and smart mode can be enabled to auto-trigger operations and reduce software complexity. The slave module implements 7-bit address match and general address call recognition in hardware. 10-bit addressing is also supported. A dedicated address mask register can act as a second address match register or as a register for address range masking. The slave continues to operate in all sleep modes, including power-down mode. This enables the slave to wake up the device from all sleep modes on TWI address match. It is possible to disable the address matching to let this be handled in software instead. The TWI module will detect START and STOP conditions, bus collisions, and bus errors. Arbitration lost, errors, collision, and clock hold on the bus are also detected and indicated in separate status flags available in both master and slave modes. [Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 42 8067O–AVR–06/2013 It is possible to disable the TWI drivers in the device, and enable a four-wire digital interface for connecting to an external TWI bus driver. This can be used for applications where the device operates from a different VCC voltage than used by the TWI bus. PORTC, PORTD, PORTE, and PORTF each has one TWI. Notation of these peripherals are TWIC, TWID, TWIE, and TWIF.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 43 8067O–AVR–06/2013 21. SPI - Serial Peripheral Interface 21.1 Features  Four identical SPI peripherals  Full-duplex, three-wire synchronous data transfer  Master or slave operation  Lsb first or msb first data transfer  Eight programmable bit rates  Interrupt flag at the end of transmission  Write collision flag to indicate data collision  Wake up from idle sleep mode  Double speed master mode 21.2 Overview The Serial Peripheral Interface (SPI) is a high-speed synchronous data transfer interface using three or four pins. It allows fast communication between an Atmel AVR XMEGA device and peripheral devices or between several microcontrollers. The SPI supports full-duplex communication. A device connected to the bus must act as a master or slave. The master initiates and controls all data transactions. PORTC, PORTD, PORTE, and PORTF each has one SPI. Notation of these peripherals are SPIC, SPID, SPIE, and SPIF.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 44 8067O–AVR–06/2013 22. USART 22.1 Features  Eight identical USART peripherals  Full-duplex operation  Asynchronous or synchronous operation  Synchronous clock rates up to 1/2 of the device clock frequency  Asynchronous clock rates up to 1/8 of the device clock frequency  Supports serial frames with 5, 6, 7, 8, or 9 data bits and 1 or 2 stop bits  Fractional baud rate generator  Can generate desired baud rate from any system clock frequency  No need for external oscillator with certain frequencies  Built-in error detection and correction schemes  Odd or even parity generation and parity check  Data overrun and framing error detection  Noise filtering includes false start bit detection and digital low-pass filter  Separate interrupts for  Transmit complete  Transmit data register empty  Receive complete  Multiprocessor communication mode  Addressing scheme to address a specific devices on a multidevice bus  Enable unaddressed devices to automatically ignore all frames  Master SPI mode  Double buffered operation  Operation up to 1/2 of the peripheral clock frequency  IRCOM module for IrDA compliant pulse modulation/demodulation 22.2 Overview The universal synchronous and asynchronous serial receiver and transmitter (USART) is a fast and flexible serial communication module. The USART supports full-duplex communication and asynchronous and synchronous operation. The USART can be configured to operate in SPI master mode and used for SPI communication. Communication is frame based, and the frame format can be customized to support a wide range of standards. The USART is buffered in both directions, enabling continued data transmission without any delay between frames. Separate interrupts for receive and transmit complete enable fully interrupt driven communication. Frame error and buffer overflow are detected in hardware and indicated with separate status flags. Even or odd parity generation and parity check can also be enabled. The clock generator includes a fractional baud rate generator that is able to generate a wide range of USART baud rates from any system clock frequencies. This removes the need to use an external crystal oscillator with a specific frequency to achieve a required baud rate. It also supports external clock input in synchronous slave operation. When the USART is set in master SPI mode, all USART-specific logic is disabled, leaving the transmit and receive buffers, shift registers, and baud rate generator enabled. Pin control and interrupt generation are identical in both modes. The registers are used in both modes, but their functionality differs for some control settings. An IRCOM module can be enabled for one USART to support IrDA 1.4 physical compliant pulse modulation and demodulation for baud rates up to 115.2Kbps. PORTC, PORTD, PORTE, and PORTF each has two USARTs. Notation of these peripherals are USARTC0, USARTC1, USARTD0, USARTD1, USARTE0, USARTE1, USARTF0 and USARTF1.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 45 8067O–AVR–06/2013 23. IRCOM - IR Communication Module 23.1 Features  Pulse modulation/demodulation for infrared communication  IrDA compatible for baud rates up to 115.2Kbps  Selectable pulse modulation scheme  3/16 of the baud rate period  Fixed pulse period, 8-bit programmable  Pulse modulation disabled  Built-in filtering  Can be connected to and used by any USART 23.2 Overview Atmel AVR XMEGA devices contain an infrared communication module (IRCOM) that is IrDA compatible for baud rates up to 115.2Kbps. It can be connected to any USART to enable infrared pulse encoding/decoding for that USART.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 46 8067O–AVR–06/2013 24. AES and DES Crypto Engine 24.1 Features  Data Encryption Standard (DES) CPU instruction  Advanced Encryption Standard (AES) crypto module  DES Instruction  Encryption and decryption  DES supported  Encryption/decryption in 16 CPU clock cycles per 8-byte block  AES crypto module  Encryption and decryption  Supports 128-bit keys  Supports XOR data load mode to the state memory  Encryption/decryption in 375 clock cycles per 16-byte block 24.2 Overview The Advanced Encryption Standard (AES) and Data Encryption Standard (DES) are two commonly used standards for cryptography. These are supported through an AES peripheral module and a DES CPU instruction, and the communication interfaces and the CPU can use these for fast, encrypted communication and secure data storage. DES is supported by an instruction in the AVR CPU. The 8-byte key and 8-byte data blocks must be loaded into the register file, and then the DES instruction must be executed 16 times to encrypt/decrypt the data block. The AES crypto module encrypts and decrypts 128-bit data blocks with the use of a 128-bit key. The key and data must be loaded into the key and state memory in the module before encryption/decryption is started. It takes 375 peripheral clock cycles before the encryption/decryption is done. The encrypted/encrypted data can then be read out, and an optional interrupt can be generated. The AES crypto module also has DMA support with transfer triggers when encryption/decryption is done and optional auto-start of encryption/decryption when the state memory is fully loaded.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 47 8067O–AVR–06/2013 25. EBI – External Bus Interface 25.1 Features  Supports SRAM up to:  512KB using 3-port EBI configuration  16MB using 3-port EBI configuration  Supports SDRAM up to:  128Mb using 3-port EBI configuration  Four software configurable chip selects  Software configurable wait state insertion  Can run from the 2x peripheral clock frequency for fast access 25.2 Overview The External Bus Interface (EBI) is used to connect external peripherals and memory for access through the data memory space. When the EBI is enabled, data address space outside the internal SRAM becomes available using dedicated EBI pins. The EBI can interface external SRAM, SDRAM, and peripherals, such as LCD displays and other memory mapped devices. The address space for the external memory is selectable from 256 bytes (8-bit) up to 16MB (24-bit). Various multiplexing modes for address and data lines can be selected for optimal use of pins when more or fewer pins are available for the EBI. The complete memory will be mapped into one linear data address space continuing from the end of the internal SRAM. The EBI has four chip selects, each with separate configuration. Each can be configured for SRAM, SRAM low pin count (LPC), or SDRAM. The EBI is clocked from the fast, 2x peripheral clock, running up to two times faster than the CPU. Four-bit and eight-bit SDRAM are supported, and SDRAM configurations, such as CAS latency and refresh rate, are configurable in software.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 48 8067O–AVR–06/2013 26. ADC - 12-bit Analog to Digital Converter 26.1 Features  Two ADCs with 12-bit resolution  2Msps sample rate for each ADC  Signed and unsigned conversions  4 result registers with individual input channel control for each ADC  8 single ended inputs for each ADC  8x4 differential inputs for each ADC  4 internal inputs:  Integrated Temperature Sensor  DAC Output  VCC voltage divided by 10  Bandgap voltage  Software selectable gain of 2, 4, 8, 16, 32 or 64  Software selectable resolution of 8- or 12-bit.  Internal or External Reference selection  Event triggered conversion for accurate timing  DMA transfer of conversion results  Interrupt/Event on compare result 26.2 Overview XMEGA A1 devices have two Analog to Digital Converters (ADC), see Figure 26-1 on page 49. The two ADC modules can be operated simultaneously, individually or synchronized. The ADC converts analog voltages to digital values. The ADC has 12-bit resolution and is capable of converting up to 2 million samples per second. The input selection is flexible, and both single-ended and differential measurements can be done. For differential measurements an optional gain stage is available to increase the dynamic range. In addition several internal signal inputs are available. The ADC can provide both signed and unsigned results. This is a pipeline ADC. A pipeline ADC consists of several consecutive stages, where each stage convert one part of the result. The pipeline design enables high sample rate at low clock speeds, and remove limitations on samples speed versus propagation delay. This also means that a new analog voltage can be sampled and a new ADC measurement started while other ADC measurements are ongoing. ADC measurements can either be started by application software or an incoming event from another peripheral in the device. Four different result registers with individual input selection (MUX selection) are provided to make it easier for the application to keep track of the data. Each result register and MUX selection pair is referred to as an ADC Channel. It is possible to use DMA to move ADC results directly to memory or peripherals when conversions are done. Both internal and external analog reference voltages can be used. An accurate internal 1.0V reference is available. An integrated temperature sensor is available and the output from this can be measured with the ADC. The output from the DAC, VCC/10 and the Bandgap voltage can also be measured by the ADC.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 49 8067O–AVR–06/2013 Figure 26-1. ADC overview Each ADC has four MUX selection registers with a corresponding result register. This means that four channels can be sampled within 1.5 µs without any intervention by the application other than starting the conversion. The results will be available in the result registers. The ADC may be configured for 8- or 12-bit result, reducing the minimum conversion time (propagation delay) from 3.5 µs for 12-bit to 2.5 µs for 8-bit result. ADC conversion results are provided left- or right adjusted with optional ‘1’ or ‘0’ padding. This eases calculation when the result is represented as a signed integer (signed 16-bit number). PORTA and PORTB each has one ADC. Notation of these peripherals are ADCA and ADCB, respectively. CH1 Result CH0 Result CH2 Result Compare < > Threshold (Int Req) Internal 1.00V Internal VCC/1.6V AREFA AREFB VINP VINN Internal signals Internal signals CH3 Result ADC0 ADC7 ADC4 ADC7 ADC0 ADC3 • • • Int. signals Int. signals Reference Voltage 1x - 64x • • • • • • ADC0 ADC7 • • •[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 50 8067O–AVR–06/2013 27. DAC - 12-bit Digital to Analog Converter 27.1 Features  12-bit resolution  Two independent, continuous-drive output channels  Up to one million samples per second conversion rate  Built-in calibration that removes:  Offset error  Gain error  Multiple conversion trigger sources  On new available data  Events from the event system  High drive capabilities and support for  Resistive loads  Capacitive loads  Combined resistive and capacitive loads  Internal and external reference options  DAC output available as input to analog comparator and ADC  Low-power mode, with reduced drive strength  Optional DMA transfer of data 27.2 Overview The XMEGA A1 devices features two 12-bit, 1 Msps DACs with built-in offset and gain calibration, see Figure 27-1 on page 50. A DAC converts a digital value into an analog signal. The DAC may use an internal 1.0 voltage as the upper limit for conversion, but it is also possible to use the supply voltage or any applied voltage in-between. The external reference input is shared with the ADC reference input. Figure 27-1. DAC overview CH1DATA CH0DATA Trigger Internal 1.00V AREFA AREFB AVCC D A T A DAC CTRL DAC CH0 REFSEL Enable 12 12 ADC DAC DAC CH1 Output Control and Driver[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 51 8067O–AVR–06/2013 Each DAC has one continuous output with high drive capabilities for both resistive and capacitive loads. It is also possible to split the continuous time channel into two Sample and Hold (S/H) channels, each with separate data conversion registers. A DAC conversion may be started from the application software by writing the data conversion registers. The DAC can also be configured to do conversions triggered by the Event System to have regular timing, independent of the application software. DMA may be used for transferring data from memory locations to DAC data registers. The DAC has a built-in calibration system to reduce offset and gain error when loading with a calibration value from software. PORTA and PORTB each has one DAC. Notation of these peripherals are DACA and DACB. respectively.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 52 8067O–AVR–06/2013 28. AC - Analog Comparator 28.1 Features  Four Analog Comparators  Selectable propagation delay versus current consumption  Selectable hysteresis  No  Small  Large  Analog comparator output available on pin  Flexible input selection  All pins on the port  Output from the DAC  Bandgap reference voltage  A 64-level programmable voltage scaler of the internal VCC voltage  Interrupt and event generation on:  Rising edge  Falling edge  Toggle  Window function interrupt and event generation on:  Signal above window  Signal inside window  Signal below window  Constant current source with configurable output pin selection 28.2 Overview The analog comparator (AC) compares the voltage levels on two inputs and gives a digital output based on this comparison. The analog comparator may be configured to generate interrupt requests and/or events upon several different combinations of input change. Two important properties of the analog comparator’s dynamic behavior are: hysteresis and propagation delay. Both of these parameters may be adjusted in order to achieve the optimal operation for each application. The input selection includes analog port pins, several internal signals, and a 64-level programmable voltage scaler. The analog comparator output state can also be output on a pin for use by external devices. A constant current source can be enabled and output on a selectable pin. This can be used to replace, for example, external resistors used to charge capacitors in capacitive touch sensing applications. The analog comparators are always grouped in pairs on each port. These are called analog comparator 0 (AC0) and analog comparator 1 (AC1). They have identical behavior, but separate control registers. Used as pair, they can be set in window mode to compare a signal to a voltage range instead of a voltage level. PORTA and PORTB each has one AC pair. Notations are ACA and ACB, respectively.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 53 8067O–AVR–06/2013 Figure 28-1. Analog comparator overview The window function is realized by connecting the external inputs of the two analog comparators in a pair as shown in Figure 28-2. Figure 28-2. Analog comparator window function ACnMUXCTRL ACnCTRL Interrupt Mode Enable Enable Hysteresis Hysteresis AC1OUT WINCTRL Interrupt Sensititivity Control & Window Function Events Interrupts AC0OUT Pin Input Pin Input Pin Input Pin Input Voltage Scaler DAC Bandgap + - + - AC0 + - AC1 + - Input signal Upper limit of window Lower limit of window Interrupt sensitivity control Interrupts Events[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 54 8067O–AVR–06/2013 29. Programming and Debugging 29.1 Features  Programming  External programming through PDI or JTAG interfaces  Minimal protocol overhead for fast operation  Built-in error detection and handling for reliable operation  Boot loader support for programming through any communication interface  Debugging  Nonintrusive, real-time, on-chip debug system  No software or hardware resources required from device except pin connection  Program flow control  Go, Stop, Reset, Step Into, Step Over, Step Out, Run-to-Cursor  Unlimited number of user program breakpoints  Unlimited number of user data breakpoints, break on:  Data location read, write, or both read and write  Data location content equal or not equal to a value  Data location content is greater or smaller than a value  Data location content is within or outside a range  No limitation on device clock frequency  Program and Debug Interface (PDI)  Two-pin interface for external programming and debugging  Uses the Reset pin and a dedicated pin  No I/O pins required during programming or debugging  JTAG interface  Four-pin, IEEE Std. 1149.1 compliant interface for programming and debugging  Boundary scan capabilities according to IEEE Std. 1149.1 (JTAG) 29.2 Overview The Program and Debug Interface (PDI) is an Atmel proprietary interface for external programming and on-chip debugging of a device. The PDI supports fast programming of nonvolatile memory (NVM) spaces; flash, EEPOM, fuses, lock bits, and the user signature row. Debug is supported through an on-chip debug system that offers nonintrusive, real-time debug. It does not require any software or hardware resources except for the device pin connection. Using the Atmel tool chain, it offers complete program flow control and support for an unlimited number of program and complex data breakpoints. Application debug can be done from a C or other high-level language source code level, as well as from an assembler and disassembler level. Programming and debugging can be done through two physical interfaces. The primary one is the PDI physical layer, which is available on all devices. This is a two-pin interface that uses the Reset pin for the clock input (PDI_CLK) and one other dedicated pin for data input and output (PDI_DATA). A JTAG interface is also available on most devices, and this can be used for programming and debugging through the four-pin JTAG interface. The JTAG interface is IEEE Std. 1149.1 compliant, and supports boundary scan. Any external programmer or on-chip debugger/emulator can be directly connected to either of these interfaces. Unless otherwise stated, all references to the PDI assume access through the PDI physical layer.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 55 8067O–AVR–06/2013 30. Pinout and Pin Functions The pinout of XMEGA A1 is shown in “Pinout/Block Diagram” on page 3. In addition to general I/O functionality, each pin may have several functions. This will depend on which peripheral is enabled and connected to the actual pin. Only one of the alternate pin functions can be used at time. 30.1 Alternate Pin Function Description The tables below shows the notation for all pin functions available and describes its function. 30.1.1 Operation/Power Supply 30.1.2 Port Interrupt functions 30.1.3 Analog functions 30.1.4 EBI functions VCC Digital supply voltage AVCC Analog supply voltage GND Ground SYNC Port pin with full synchronous and limited asynchronous interrupt function ASYNC Port pin with full synchronous and full asynchronous interrupt function ACn Analog Comparator input pin n AC0OUT Analog Comparator 0 Output ADCn Analog to Digital Converter input pin n DACn Digital to Analog Converter output pin n AREF Analog Reference input pin An Address line n Dn Data line n CSn Chip Select n ALEn Address Latch Enable pin n (SRAM) RE Read Enable (SRAM) WE External Data Memory Write (SRAM /SDRAM) BAn Bank Address (SDRAM) CAS Column Access Strobe (SDRAM) CKE SDRAM Clock Enable (SDRAM)[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 56 8067O–AVR–06/2013 30.1.5 Timer/Counter and AWEX functions 30.1.6 Communication functions 30.1.7 Oscillators, Clock and Event CLK SDRAM Clock (SDRAM) DQM Data Mask Signal/Output Enable (SDRAM) RAS Row Access Strobe (SDRAM) 2P 2 Port Interface 3P 3 Port Interface OCnx Output Compare Channel x for Timer/Counter n OCnx Inverted Output Compare Channel x for Timer/Counter n OCnxLS Output Compare Channel x Low Side for Timer/Counter n OCnxHS Output Compare Channel x High Side for Timer/Counter n SCL Serial Clock for TWI SDA Serial Data for TWI SCLIN Serial Clock In for TWI when external driver interface is enabled SCLOUT Serial Clock Out for TWI when external driver interface is enabled SDAIN Serial Data In for TWI when external driver interface is enabled SDAOUT Serial Data Out for TWI when external driver interface is enabled XCKn Transfer Clock for USART n RXDn Receiver Data for USART n TXDn Transmitter Data for USART n SS Slave Select for SPI MOSI Master Out Slave In for SPI MISO Master In Slave Out for SPI SCK Serial Clock for SPI n Timer Oscillator pin n XTALn Input/Output for inverting Oscillator pin n CLKOUT Peripheral Clock Output EVOUT Event Channel 0 Output[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 57 8067O–AVR–06/2013 30.1.8 Debug/System functions RESET Reset pin PDI_CLK Program and Debug Interface Clock pin PDI_DATA Program and Debug Interface Data pin TCK JTAG Test Clock TDI JTAG Test Data In TDO JTAG Test Data Out TMS JTAG Test Mode Select[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 58 8067O–AVR–06/2013 30.2 Alternate Pin Functions The tables below show the primary/default function for each pin on a port in the first column, the pin number in the second column, and then all alternate pin functions in the remaining columns. The head row shows what peripheral that enable and use the alternate pin functions. Table 30-1. Port A - Alternate functions. Table 30-2. Port B - Alternate functions. Table 30-3. Port C - Alternate functions. PORT A PIN # INTERRUPT ADCA POS ADCA NEG ADCA GAINPOS ADCA GAINNEG ACA POS ACA NEG ACA OUT DACA REFA GND 93 AVCC 94 PA0 95 SYNC ADC0 ADC0 ADC0 AC0 AC0 AREF PA1 96 SYNC ADC1 ADC1 ADC1 AC1 AC1 PA2 97 SYNC/ASYNC ADC2 ADC2 ADC2 AC2 DAC0 PA3 98 SYNC ADC3 ADC3 ADC3 AC3 AC3 DAC1 PA4 99 SYNC ADC4 ADC4 ADC4 AC4 PA5 100 SYNC ADC5 ADC5 ADC5 AC5 AC5 PA6 1 SYNC ADC6 ADC6 ADC6 AC6 PA7 2 SYNC ADC7 ADC7 ADC7 AC7 AC0OUT PORT B PIN # INTERRUPT ADCB POS ADCB NEG ADCB GAINPOS ADCB GAINNEG ACB POS ACB NEG ACB OUT DACB REFB JTAG GND 3 AVCC 4 PB0 5 SYNC ADC0 ADC0 ADC0 AC0 AC0 AREF PB1 6 SYNC ADC1 ADC1 ADC1 AC1 AC1 PB2 7 SYNC/ASYNC ADC2 ADC2 ADC2 AC2 DAC0 PB3 8 SYNC ADC3 ADC3 ADC3 AC3 AC3 DAC1 PB4 9 SYNC ADC4 ADC4 ADC4 AC4 TMS PB5 10 SYNC ADC5 ADC5 ADC5 AC5 AC5 TDI PB6 11 SYNC ADC6 ADC6 ADC6 AC6 TCK PB7 12 SYNC ADC7 ADC7 ADC7 AC7 AC0OUT TDO PORT C PIN # INTERRUPT TCC0 AWEXC TCC1 USARTC0 USARTC1 SPIC TWIC CLOCKOUT EVENTOUT GND 13 VCC 14 PC0 15 SYNC OC0A OC0ALS SDA PC1 16 SYNC OC0B OC0AHS XCK0 SCL PC2 17 SYNC/ASYNC OC0C OC0BLS RXD0[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 59 8067O–AVR–06/2013 Table 30-4. Port D - Alternate functions. Table 30-5. Port E - Alternate functions. Table 30-6. Port F - Alternate functions. PC3 18 SYNC OC0D OC0BHS TXD0 PC4 19 SYNC OC0CLS OC1A SS PC5 20 SYNC OC0CHS OC1B XCK1 MOSI PC6 21 SYNC OC0DLS RXD1 MISO PC7 22 SYNC OC0DHS TXD1 SCK CLKOUT EVOUT PORT D PIN # INTERRUPT TCD0 TCD1 USARTD0 USARTD1 SPID TWID CLOCKOUT EVENTOUT GND 23 VCC 24 PD0 25 SYNC OC0A SDA PD1 26 SYNC OC0B XCK0 SCL PD2 27 SYNC/ASYNC OC0C RXD0 PD3 28 SYNC OC0D TXD0 PD4 29 SYNC OC1A SS PD5 30 SYNC OC1B XCK1 MOSI PD6 31 SYNC RXD1 MISO PD7 32 SYNC TXD1 SCK CLKOUT EVOUT PORT E PIN # INTERRUPT TCE0 AWEXE TCE1 USARTE0 USARTE1 SPIE TWIE CLOCKOUT EVENTOUT GND 33 VCC 34 PE0 35 SYNC OC0A OC0ALS SDA PE1 36 SYNC OC0B OC0AHS XCK0 SCL PE2 37 SYNC/ASYNC OC0C OC0BLS RXD0 PE3 38 SYNC OC0D OC0BHS TXD0 PE4 39 SYNC OC0CLS OC1A SS PE5 40 SYNC OC0CHS OC1B XCK1 MOSI PE6 41 SYNC OC0DLS RXD1 MISO PE7 42 SYNC OC0DHS TXD1 SCK CLKOUT EVOUT PORT F PIN # INTERRUPT TCF0 TCF1 USARTF0 USARTF1 SPIF TWIF GND 43 VCC 44 PF0 45 SYNC OC0A SDA PORT C PIN # INTERRUPT TCC0 AWEXC TCC1 USARTC0 USARTC1 SPIC TWIC CLOCKOUT EVENTOUT[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 60 8067O–AVR–06/2013 Table 30-7. Port H - Alternate functions. Table 30-8. Port J - Alternate functions. PF1 46 SYNC OC0B XCK0 SCL PF2 47 SYNC/ASYNC OC0C RXD0 PF3 48 SYNC OC0D TXD0 PF4 49 SYNC OC1A SS PF5 50 SYNC OC1B XCK1 MOSI PF6 51 SYNC RXD1 MISO PF7 52 SYNC TXD1 SCK PORT H PIN # INTERRUPT SDRAM 3P SRAM ALE1 3P SRAM ALE12 3P LPC ALE1 3P LPC ALE1 2P LPC ALE12 2P GND 53 VCC 54 PH0 55 SYNC WE WE WE WE WE WE PH1 56 SYNC CAS RE RE RE RE RE PH2 57 SYNC/ASYNC RAS ALE1 ALE1 ALE1 ALE1 ALE1 PH3 58 SYNC DQM ALE2 ALE2 PH4 59 SYNC BA0 CS0/A16 CS0 CS0/A16 CS0 CS0/A16 PH5 60 SYNC BA1 CS1/A17 CS1 CS1/A17 CS1 CS1/A17 PH6 61 SYNC CKE CS2/A18 CS2 CS2/A18 CS2 CS2/A18 PH7 62 SYNC CLK CS3/A19 CS3 CS3/A19 CS3 CS3/A19 PORT J PIN # INTERRUPT SDRAM 3P SRAM ALE1 3P SRAM ALE12 3P LPC ALE1 3P LPC ALE1 2P LPC ALE12 2P GND 63 VCC 64 PJ0 65 SYNC D0 D0 D0 D0/A0 D0/A0 D0/A0/A8 PJ1 66 SYNC D1 D1 D1 D1/A1 D1/A1 D1/A1/A9 PJ2 67 SYNC/ASYNC D2 D2 D2 D2/A2 D2/A2 D2/A2/A10 PJ3 68 SYNC D3 D3 D3 D3/A3 D3/A3 D3/A3/A11 PJ4 69 SYNC A8 D4 D4 D4/A4 D4/A4 D4/A4/A12 PJ5 70 SYNC A9 D5 D5 D5/A5 D5/A5 D5/A5/A13 PJ6 71 SYNC A10 D6 D6 D6/A6 D6/A6 D6/A6/A14 PJ7 72 SYNC A11 D7 D7 D7/A7 D7/A7 D7/A7/A15 PORT F PIN # INTERRUPT TCF0 TCF1 USARTF0 USARTF1 SPIF TWIF[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 61 8067O–AVR–06/2013 Table 30-9. Port K - Alternate functions. Table 30-10. Port Q - Alternate functions. Table 30-11. Port R - Alternate functions. PORT K PIN # INTERRUPT SDRAM 3P SRAM ALE1 3P SRAM ALE12 3P LPC ALE1 3P LPC ALE1 2P LPC ALE12 2P GND 73 VCC 74 PK0 75 SYNC A0 A0/A8 A0/A8/A16 A8 PK1 76 SYNC A1 A1/A9 A1/A9/A17 A9 PK2 77 SYNC/ASYNC A2 A2/A10 A2/A10/A18 A10 PK3 78 SYNC A3 A3/A11 A3/A11/A19 A11 PK4 79 SYNC A4 A4/A12 A4/A12/A20 A12 PK5 80 SYNC A5 A5/A13 A5/A13/A21 A13 PK6 81 SYNC A6 A6/A14 A6/A14/A22 A14 PK7 82 SYNC A7 A7/A15 A7/A15/A23 A15 PORT Q PIN # INTERRUPT VCC 83 GND 84 PQ0 85 SYNC TOSC1 (Input) PQ1 86 SYNC TOSC2 (Output) PQ2 87 SYNC/ASYNC PQ3 88 SYNC PORT R PIN # INTERRUPT PDI XTAL PDI 89 PDI_DATA RESET 90 PDI_CLOCK PRO 91 SYNC XTAL2 PR1 92 SYNC XTAL1[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 62 8067O–AVR–06/2013 31. Peripheral Module Address Map The address maps show the base address for each peripheral and module in XMEGA A1. For complete register description and summary for each peripheral module, refer to the XMEGA A Manual. Table 31-1. Peripheral Module Address Map Base Address Name Description 0x0000 GPIO General Purpose IO Registers 0x0010 VPORT0 Virtual Port 0 0x0014 VPORT1 Virtual Port 1 0x0018 VPORT2 Virtual Port 2 0x001C VPORT3 Virtual Port 3 0x0030 CPU CPU 0x0040 CLK Clock Control 0x0048 SLEEP Sleep Controller 0x0050 OSC Oscillator Control 0x0060 DFLLRC32M DFLL for the 32 MHz Internal RC Oscillator 0x0068 DFLLRC2M DFLL for the 2 MHz RC Oscillator 0x0070 PR Power Reduction 0x0078 RST Reset Controller 0x0080 WDT Watch-Dog Timer 0x0090 MCU MCU Control 0x00A0 PMIC Programmable Multilevel Interrupt Controller 0x00B0 PORTCFG Port Configuration 0x00C0 AES AES Module 0x0100 DMA DMA Controller 0x0180 EVSYS Event System 0x01C0 NVM Non Volatile Memory (NVM) Controller 0x0200 ADCA Analog to Digital Converter on port A 0x0240 ADCB Analog to Digital Converter on port B 0x0300 DACA Digital to Analog Converter on port A 0x0320 DACB Digital to Analog Converter on port B 0x0380 ACA Analog Comparator pair on port A 0x0390 ACB Analog Comparator pair on port B 0x0400 RTC Real Time Counter 0x0440 EBI External Bus Interface 0x0480 TWIC Two Wire Interface on port C 0x0490 TWID Two Wire Interface on port D[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 63 8067O–AVR–06/2013 0x04A0 TWIE Two Wire Interface on port E 0x04B0 TWIF Two Wire Interface on port F 0x0600 PORTA Port A 0x0620 PORTB Port B 0x0640 PORTC Port C 0x0660 PORTD Port D 0x0680 PORTE Port E 0x06A0 PORTF Port F 0x06E0 PORTH Port H 0x0700 PORTJ Port J 0x0720 PORTK Port K 0x07C0 PORTQ Port Q 0x07E0 PORTR Port R 0x0800 TCC0 Timer/Counter 0 on port C 0x0840 TCC1 Timer/Counter 1 on port C 0x0880 AWEXC Advanced Waveform Extension on port C 0x0890 HIRESC High Resolution Extension on port C 0x08A0 USARTC0 USART 0 on port C 0x08B0 USARTC1 USART 1 on port C 0x08C0 SPIC Serial Peripheral Interface on port C 0x08F8 IRCOM Infrared Communication Module 0x0900 TCD0 Timer/Counter 0 on port D 0x0940 TCD1 Timer/Counter 1 on port D 0x0990 HIRESD High Resolution Extension on port D 0x09A0 USARTD0 USART 0 on port D 0x09B0 USARTD1 USART 1 on port D 0x09C0 SPID Serial Peripheral Interface on port D 0x0A00 TCE0 Timer/Counter 0 on port E 0x0A40 TCE1 Timer/Counter 1 on port E 0x0A80 AWEXE Advanced Waveform Extension on port E 0x0A90 HIRESE High Resolution Extension on port E 0x0AA0 USARTE0 USART 0 on port E 0x0AB0 USARTE1 USART 1 on port E 0x0AC0 SPIE Serial Peripheral Interface on port E 0x0B00 TCF0 Timer/Counter 0 on port F Base Address Name Description[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 64 8067O–AVR–06/2013 0x0B40 TCF1 Timer/Counter 1 on port F 0x0B90 HIRESF High Resolution Extension on port F 0x0BA0 USARTF0 USART 0 on port F 0x0BB0 USARTF1 USART 1 on port F 0x0BC0 SPIF Serial Peripheral Interface on port F Base Address Name Description[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 65 8067O–AVR–06/2013 32. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks Arithmetic and Logic Instructions ADD Rd, Rr Add without Carry Rd  Rd + Rr Z,C,N,V,S,H 1 ADC Rd, Rr Add with Carry Rd  Rd + Rr + C Z,C,N,V,S,H 1 ADIW Rd, K Add Immediate to Word Rd  Rd + 1:Rd + K Z,C,N,V,S 2 SUB Rd, Rr Subtract without Carry Rd  Rd - Rr Z,C,N,V,S,H 1 SUBI Rd, K Subtract Immediate Rd  Rd - K Z,C,N,V,S,H 1 SBC Rd, Rr Subtract with Carry Rd  Rd - Rr - C Z,C,N,V,S,H 1 SBCI Rd, K Subtract Immediate with Carry Rd  Rd - K - C Z,C,N,V,S,H 1 SBIW Rd, K Subtract Immediate from Word Rd + 1:Rd  Rd + 1:Rd - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Rd  Rd  Rr Z,N,V,S 1 ANDI Rd, K Logical AND with Immediate Rd  Rd  K Z,N,V,S 1 OR Rd, Rr Logical OR Rd  Rd v Rr Z,N,V,S 1 ORI Rd, K Logical OR with Immediate Rd  Rd v K Z,N,V,S 1 EOR Rd, Rr Exclusive OR Rd  Rd  Rr Z,N,V,S 1 COM Rd One’s Complement Rd  $FF - Rd Z,C,N,V,S 1 NEG Rd Two’s Complement Rd  $00 - Rd Z,C,N,V,S,H 1 SBR Rd,K Set Bit(s) in Register Rd  Rd v K Z,N,V,S 1 CBR Rd,K Clear Bit(s) in Register Rd  Rd  ($FFh - K) Z,N,V,S 1 INC Rd Increment Rd  Rd + 1 Z,N,V,S 1 DEC Rd Decrement Rd  Rd - 1 Z,N,V,S 1 TST Rd Test for Zero or Minus Rd  Rd  Rd Z,N,V,S 1 CLR Rd Clear Register Rd  Rd  Rd Z,N,V,S 1 SER Rd Set Register Rd  $FF None 1 MUL Rd,Rr Multiply Unsigned R1:R0  Rd x Rr (UU) Z,C 2 MULS Rd,Rr Multiply Signed R1:R0  Rd x Rr (SS) Z,C 2 MULSU Rd,Rr Multiply Signed with Unsigned R1:R0  Rd x Rr (SU) Z,C 2 FMUL Rd,Rr Fractional Multiply Unsigned R1:R0  Rd x Rr<<1 (UU) Z,C 2 FMULS Rd,Rr Fractional Multiply Signed R1:R0  Rd x Rr<<1 (SS) Z,C 2 FMULSU Rd,Rr Fractional Multiply Signed with Unsigned R1:R0  Rd x Rr<<1 (SU) Z,C 2 DES K Data Encryption if (H = 0) then R15:R0 else if (H = 1) then R15:R0   Encrypt(R15:R0, K) Decrypt(R15:R0, K) 1/2 Branch Instructions RJMP k Relative Jump PC  PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC(15:0) PC(21:16)   Z, 0 None 2 EIJMP Extended Indirect Jump to (Z) PC(15:0) PC(21:16)   Z, EIND None 2 JMP k Jump PC  k None 3[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 66 8067O–AVR–06/2013 RCALL k Relative Call Subroutine PC  PC + k + 1 None 2 / 3(1) ICALL Indirect Call to (Z) PC(15:0) PC(21:16)   Z, 0 None 2 / 3(1) EICALL Extended Indirect Call to (Z) PC(15:0) PC(21:16)   Z, EIND None 3(1) CALL k call Subroutine PC  k None 3 / 4(1) RET Subroutine Return PC  STACK None 4 / 5(1) RETI Interrupt Return PC  STACK I 4 / 5(1) CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC  PC + 2 or 3 None 1 / 2 / 3 CP Rd,Rr Compare Rd - Rr Z,C,N,V,S,H 1 CPC Rd,Rr Compare with Carry Rd - Rr - C Z,C,N,V,S,H 1 CPI Rd,K Compare with Immediate Rd - K Z,C,N,V,S,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b) = 0) PC  PC + 2 or 3 None 1 / 2 / 3 SBRS Rr, b Skip if Bit in Register Set if (Rr(b) = 1) PC  PC + 2 or 3 None 1 / 2 / 3 SBIC A, b Skip if Bit in I/O Register Cleared if (I/O(A,b) = 0) PC  PC + 2 or 3 None 2 / 3 / 4 SBIS A, b Skip if Bit in I/O Register Set If (I/O(A,b) =1) PC  PC + 2 or 3 None 2 / 3 / 4 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PC  PC + k + 1 None 1 / 2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PC  PC + k + 1 None 1 / 2 BREQ k Branch if Equal if (Z = 1) then PC  PC + k + 1 None 1 / 2 BRNE k Branch if Not Equal if (Z = 0) then PC  PC + k + 1 None 1 / 2 BRCS k Branch if Carry Set if (C = 1) then PC  PC + k + 1 None 1 / 2 BRCC k Branch if Carry Cleared if (C = 0) then PC  PC + k + 1 None 1 / 2 BRSH k Branch if Same or Higher if (C = 0) then PC  PC + k + 1 None 1 / 2 BRLO k Branch if Lower if (C = 1) then PC  PC + k + 1 None 1 / 2 BRMI k Branch if Minus if (N = 1) then PC  PC + k + 1 None 1 / 2 BRPL k Branch if Plus if (N = 0) then PC  PC + k + 1 None 1 / 2 BRGE k Branch if Greater or Equal, Signed if (N  V= 0) then PC  PC + k + 1 None 1 / 2 BRLT k Branch if Less Than, Signed if (N  V= 1) then PC  PC + k + 1 None 1 / 2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC  PC + k + 1 None 1 / 2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC  PC + k + 1 None 1 / 2 BRTS k Branch if T Flag Set if (T = 1) then PC  PC + k + 1 None 1 / 2 BRTC k Branch if T Flag Cleared if (T = 0) then PC  PC + k + 1 None 1 / 2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC  PC + k + 1 None 1 / 2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC  PC + k + 1 None 1 / 2 BRIE k Branch if Interrupt Enabled if (I = 1) then PC  PC + k + 1 None 1 / 2 BRID k Branch if Interrupt Disabled if (I = 0) then PC  PC + k + 1 None 1 / 2 Data Transfer Instructions MOV Rd, Rr Copy Register Rd  Rr None 1 MOVW Rd, Rr Copy Register Pair Rd+1:Rd  Rr+1:Rr None 1 Mnemonics Operands Description Operation Flags #Clocks[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 67 8067O–AVR–06/2013 LDI Rd, K Load Immediate Rd  K None 1 LDS Rd, k Load Direct from data space Rd  (k) None 2(1)(2) LD Rd, X Load Indirect Rd  (X) None 1(1)(2) LD Rd, X+ Load Indirect and Post-Increment Rd X   (X) X + 1 None 1(1)(2) LD Rd, -X Load Indirect and Pre-Decrement X  X - 1, Rd  (X)   X - 1 (X) None 2(1)(2) LD Rd, Y Load Indirect Rd  (Y)  (Y) None 1(1)(2) LD Rd, Y+ Load Indirect and Post-Increment Rd Y   (Y) Y + 1 None 1(1)(2) LD Rd, -Y Load Indirect and Pre-Decrement Y Rd   Y - 1 (Y) None 2(1)(2) LDD Rd, Y+q Load Indirect with Displacement Rd  (Y + q) None 2(1)(2) LD Rd, Z Load Indirect Rd  (Z) None 1(1)(2) LD Rd, Z+ Load Indirect and Post-Increment Rd Z   (Z), Z+1 None 1(1)(2) LD Rd, -Z Load Indirect and Pre-Decrement Z Rd   Z - 1, (Z) None 2(1)(2) LDD Rd, Z+q Load Indirect with Displacement Rd  (Z + q) None 2(1)(2) STS k, Rr Store Direct to Data Space (k)  Rd None 2(1) ST X, Rr Store Indirect (X)  Rr None 1(1) ST X+, Rr Store Indirect and Post-Increment (X) X   Rr, X + 1 None 1(1) ST -X, Rr Store Indirect and Pre-Decrement X (X)   X - 1, Rr None 2(1) ST Y, Rr Store Indirect (Y)  Rr None 1(1) ST Y+, Rr Store Indirect and Post-Increment (Y) Y   Rr, Y + 1 None 1(1) ST -Y, Rr Store Indirect and Pre-Decrement Y (Y)   Y - 1, Rr None 2(1) STD Y+q, Rr Store Indirect with Displacement (Y + q)  Rr None 2(1) ST Z, Rr Store Indirect (Z)  Rr None 1(1) ST Z+, Rr Store Indirect and Post-Increment (Z) Z   Rr Z + 1 None 1(1) ST -Z, Rr Store Indirect and Pre-Decrement Z  Z - 1 None 2(1) STD Z+q,Rr Store Indirect with Displacement (Z + q)  Rr None 2(1) LPM Load Program Memory R0  (Z) None 3 LPM Rd, Z Load Program Memory Rd  (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Increment Rd Z   (Z), Z + 1 None 3 ELPM Extended Load Program Memory R0  (RAMPZ:Z) None 3 ELPM Rd, Z Extended Load Program Memory Rd  (RAMPZ:Z) None 3 ELPM Rd, Z+ Extended Load Program Memory and PostIncrement Rd Z   (RAMPZ:Z), Z + 1 None 3 SPM Store Program Memory (RAMPZ:Z)  R1:R0 None - Mnemonics Operands Description Operation Flags #Clocks[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 68 8067O–AVR–06/2013 SPM Z+ Store Program Memory and Post-Increment by 2 (RAMPZ:Z) Z   R1:R0, Z + 2 None - IN Rd, A In From I/O Location Rd  I/O(A) None 1 OUT A, Rr Out To I/O Location I/O(A)  Rr None 1 PUSH Rr Push Register on Stack STACK  Rr None 1(1) POP Rd Pop Register from Stack Rd  STACK None 2(1) Bit and Bit-test Instructions LSL Rd Logical Shift Left Rd(n+1) Rd(0) C    Rd(n), 0, Rd(7) Z,C,N,V,H 1 LSR Rd Logical Shift Right Rd(n) Rd(7) C    Rd(n+1), 0, Rd(0) Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0) Rd(n+1) C    C, Rd(n), Rd(7) Z,C,N,V,H 1 ROR Rd Rotate Right Through Carry Rd(7) Rd(n) C    C, Rd(n+1), Rd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n)  Rd(n+1), n=0..6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3..0)  Rd(7..4) None 1 BSET s Flag Set SREG(s)  1 SREG(s) 1 BCLR s Flag Clear SREG(s)  0 SREG(s) 1 SBI A, b Set Bit in I/O Register I/O(A, b)  1 None 1 CBI A, b Clear Bit in I/O Register I/O(A, b)  0 None 1 BST Rr, b Bit Store from Register to T T  Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b)  T None 1 SEC Set Carry C  1 C 1 CLC Clear Carry C  0 C 1 SEN Set Negative Flag N  1 N 1 CLN Clear Negative Flag N  0 N 1 SEZ Set Zero Flag Z  1 Z 1 CLZ Clear Zero Flag Z  0 Z 1 SEI Global Interrupt Enable I  1 I 1 CLI Global Interrupt Disable I  0 I 1 SES Set Signed Test Flag S  1 S 1 CLS Clear Signed Test Flag S  0 S 1 SEV Set Two’s Complement Overflow V  1 V 1 CLV Clear Two’s Complement Overflow V  0 V 1 SET Set T in SREG T  1 T 1 CLT Clear T in SREG T  0 T 1 SEH Set Half Carry Flag in SREG H  1 H 1 CLH Clear Half Carry Flag in SREG H  0 H 1 Mnemonics Operands Description Operation Flags #Clocks[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 69 8067O–AVR–06/2013 Notes: 1. Cycle times for Data memory accesses assume internal memory accesses, and are not valid for accesses via the external RAM interface. 2. One extra cycle must be added when accessing Internal SRAM. MCU Control Instructions BREAK Break (See specific descr. for BREAK) None 1 NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep) None 1 WDR Watchdog Reset (see specific descr. for WDR) None 1 Mnemonics Operands Description Operation Flags #Clocks[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 70 8067O–AVR–06/2013 33. Packaging information 33.1 100A 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 100A, 100-lead, 14 x 14 mm Body Size, 1.0 mm Body Thickness, 0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP) 100A D 2010-10-20 PIN 1 IDENTIFIER 0°~7° PIN 1 L C A1 A2 A D1 D e E1 E B A – – 1.20 A1 0.05 – 0.15 A2 0.95 1.00 1.05 D 15.75 16.00 16.25 D1 13.90 14.00 14.10 Note 2 E 15.75 16.00 16.25 E1 13.90 14.00 14.10 Note 2 B 0.17 – 0.27 C 0.09 – 0.20 L 0.45 – 0.75 e 0.50 TYP Notes: 1. This package conforms to JEDEC reference MS-026, Variation AED. 2. Dimensions D1 and E1 do not include mold protrusion. Allowable protrusion is 0.25 mm per side. Dimensions D1 and E1 are maximum plastic body size dimensions including mold mismatch. 3. Lead coplanarity is 0.08 mm maximum. COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 71 8067O–AVR–06/2013 33.2 100C1 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 100C1, 100-ball, 9 x 9 x 1.2 mm Body, Ball Pitch 0.80 mm Chip Array BGA Package (CBGA) 100C1 A 5/25/06 TOP VIEW SIDE VIEW BOTTOM VIEW COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A 1.10 – 1.20 A1 0.30 0.35 0.40 D 8.90 9.00 9.10 E 8.90 9.00 9.10 D1 7.10 7.20 7.30 E1 7.10 7.20 7.30 Øb 0.35 0.40 0.45 e 0.80 TYP Marked A1 Identifier 8 7 6 5 4 3 2 1 A B C D E 9 F G H I J 10 0.90 TYP 0.90 TYP A1 Corner 0.12 Z E D e e Øb A A1 E1 D1[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 72 8067O–AVR–06/2013 33.3 100C2 TITLE GPC DRAWING NO. REV. Package Drawing Contact: packagedrawings@atmel.com CIF A 100C2 100C2, 100-ball (10 x 10 Array), 0.65 mm Pitch, 7.0 x 7.0 x 1.0 mm, Very Thin, Fine-Pitch Ball Grid Array Package (VFBGA) 12/23/08 COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A – – 1.00 A1 0.20 – – A2 0.65 – – D 6.90 7.00 7.10 D1 5.85 BSC E 6.90 7.00 7.10 E1 5.85 BSC b 0.30 0.35 0.40 e 0.65 BSC TOP VIEW SIDE VIEW A1 BALL ID J I H G F E D C B A 12 3 4 5 6 7 8 9 10 A A1 A2 D E 0.10 E1 D1 100 - Ø0.35 ± 0.05 e A1 BALL CORNER BOTTOM VIEW b e[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 73 8067O–AVR–06/2013 34. Electrical Characteristics 34.1 Absolute Maximum Ratings* 34.2 DC Characteristics Table 34-1. Current consumption. Operating Temperature . . . . . . . . . . . -55C to +125C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature . . . . . . . . . . . . . -65C to +150°C Voltage on any Pin with respect to Ground-0.5V to VCC+0.5V Maximum Operating Voltage . . . . . . . . . . . . . . . . 3.6V DC Current per I/O Pin. . . . . . . . . . . . . . . . . . 20.0 mA DC Current VCC and GND Pins . . . . . . . . . . 200.0 mA Symbol Parameter Condition Min Typ Max Units ICC Active mode(1) 1 MHz, Ext. Clk VCC = 1.8V 365 µA VCC = 3.0V 790 2 MHz, Ext. Clk VCC = 1.8V 690 800 VCC = 3.0V 1400 1600 32 MHz, Ext. Clk VCC = 3.0V 18.35 20 mA Idle mode(1) 1 MHz, Ext. Clk VCC = 1.8V 135 µA VCC = 3.0V 255 2 MHz, Ext. Clk VCC = 1.8V 270 380 VCC = 3.0V 510 650 32 MHz, Ext. Clk VCC = 3.0V 8.15 9.2 mA Power-down mode All Functions Disabled VCC = 3.0V 0.1 µA All Functions Disabled, T = 85°C VCC = 3.0V 2 5 ULP, WDT, Sampled BOD VCC = 1.8V 0.5 VCC = 3.0V 0.6 ULP, WDT, Sampled BOD, T=85°C VCC = 3.0V 3 10 Power-save mode RTC 1 kHz from Low Power 32 kHz VCC = 1.8V 0.52 VCC = 3.0V 0.55 µA RTC from Low Power 32 kHz VCC = 3.0V 1.16[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 74 8067O–AVR–06/2013 Note: 1. All Power Reduction Registers set. Typical numbers measured at T = 25°C if nothing else is specified. 2. with no prescaling Module current consumption(2) ICC RC32M 395 µA RC32M w/DFLL Internal 32.768 kHz oscillator as DFLL source TBD RC2M 120 RC2M w/DFLL Internal 32.768 kHz oscillator as DFLL source 155 RC32K 30 PLL Multiplication factor = 10x 195 Watchdog normal mode TBD BOD Continuous mode 120 BOD Sampled mode 1 Internal 1.00 V ref 85 Temperature reference 80 RTC with int. 32 kHz RC as source No prescaling 30 RTC with ULP as source No prescaling 1 ADC 250 kS/s - Int. 1V Ref 3.6 DAC Normal Mode 1000 kS/s, Single channel, Int. 1V Ref 1.8 mA DAC Low-Power Mode 1000 KS/s, Single channel, Int. 1V Ref 1 AC High-speed 220 µA AC Low-power 110 USART Rx and Tx enabled, 9600 BAUD 7.5 DMA 180 Timer/Counter Prescaler DIV1 18 AES 195 Flash/EEPROM Programming Vcc = 2V 20 mA Vcc = 3V 30 Symbol Parameter Condition Min Typ Max Units[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 75 8067O–AVR–06/2013 34.3 Speed Table 34-2. Operating voltage and frequency. The maximum CPU clock frequency of the XMEGA A1 devices is depending on VCC. As shown in Figure 34-1 on page 75 the Frequency vs. VCC curve is linear between 1.8V < VCC < 2.7V. Figure 34-1. Maximum Frequency vs. Vcc Symbol Parameter Condition Min Typ Max Units ClkCPU CPU clock frequency VCC = 1.6V 0 12 MHz VCC = 1.8V 0 12 VCC = 2.7V 0 32 VCC = 3.6V 0 32 1.8 12 32 MHz 1.6 2.7 3.6 V Safe Operating Area[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 76 8067O–AVR–06/2013 34.4 Flash and EEPROM Memory Characteristics Table 34-3. Endurance and data retention. Table 34-4. Programming time. Notes: 1. Programming is timed from the internal 2 MHz oscillator. 2. EEPROM is not erased if the EESAVE fuse is programmed. 34.5 ADC Characteristics Table 34-5. ADC characteristics Symbol Parameter Condition Min Typ Max Units Flash Write/Erase cycles 25°C 10K Cycle 85°C 10K Data retention 25°C 100 Year 55°C 25 EEPROM Write/Erase cycles 25°C 80K Cycle 85°C 30K Data retention 25°C 100 Year 55°C 25 Symbol Parameter Condition Min Typ(1) Max Units Chip Erase Flash, EEPROM(2) and SRAM Erase 40 ms Flash Page Erase 4 Page Write 6 Page WriteAutomatic Page Erase and Write 12 EEPROM Page Erase 4 Page Write 6 Page Write Automatic Page Erase and Write 12 Symbol Parameter Condition Min Typ Max Units RES Resolution Programmable: 8/12 8 12 12 Bits INL Integral Non-Linearity 500 kS/s -5 <±1 5 LSB DNL Differential Non-Linearity 500 kS/s < ±0.75 LSB Gain Error ±10 mV Offset Error ±2 mV ADCclk ADC Clock frequency Max is 1/4 of Peripheral Clock VCC2.0V 2000 kHz VCC<2.0V 500[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 77 8067O–AVR–06/2013 Table 34-6. ADC gain stage characteristics. Conversion rate VCC2.0V 2000 ksps VCC<2.0V 500 Conversion time (propagation delay) (RES+2)/2+GAIN RES = 8 or 12, GAIN = 0 or 1 5 7 8 ADCclk cycles Sampling Time 1/2 ADCclk cycle 0.25 µS Conversion range 0 VREF V AVCC Analog Supply Voltage Vcc-0.3 Vcc+0.3 V VREF Reference voltage 1.0 Vcc-0.6 V Input bandwidth VCC2.0V 2000 kHz VCC<2.0V 500 INT1V Internal 1.00V reference 1.00 V INTVCC Internal VCC/1.6 VCC/1.6 V SCALEDVCC Scaled internal VCC/10 input VCC/10 V RAREF Reference input resistance >10 M Start-up time 12 24 ADCclk cycles Internal input sampling speed Temp. sensor, VCC/10, Bandgap 100 ksps Symbol Parameter Condition Min Typ Max Units Gain error 1 to 64 gain < ±1 % Offset error < ±1 mV Vrms Noise level at input 64x gain VREF = Int. 1V 0.12 mV VREF = Ext. 2V 0.06 Clock rate Same as ADC 1000 kHz Symbol Parameter Condition Min Typ Max Units[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 78 8067O–AVR–06/2013 34.6 DAC Characteristics Table 34-7. DAC characteristics. 34.7 Analog Comparator Characteristics Table 34-8. Analog Comparator characteristics. 34.8 Bandgap Characteristics Table 34-9. Bandgap voltage characteristics. Symbol Parameter Condition Min Typ Max Units INL Integral Non-Linearity VCC = 1.6-3.6V VREF = Ext. ref 5 LSB DNL Differential Non-Linearity VCC = 1.6-3.6V VREF = Ext. ref 0.6 <±1 LSB VREF= AVCC 0.6 Fclk Conversion rate 1000 ksps AREF External reference voltage 1.1 AVCC-0.6 V Reference input impedance >10 M Max output voltage Rload=100k AVCC*0.98 V Min output voltage Rload=100k 0.01 V Symbol Parameter Condition Min Typ Max Units Voff Input Offset Voltage VCC = 1.6 - 3.6V <±5 mV Ilk Input Leakage Current VCC = 1.6 - 3.6V < 1000 pA Vhys1 Hysteresis, No VCC = 1.6 - 3.6V 0 mV Vhys2 Hysteresis, Small VCC = 1.6 - 3.6V mode = HS 25 mV Vhys3 Hysteresis, Large VCC = 1.6 - 3.6V mode = HS 50 mV tdelay Propagation delay VCC = 3.0V, T= 85°C mode = HS 100 V ns CC = 1.6 - 3.6V mode = HS 70 VCC = 1.6 - 3.6V mode = LP 140 Symbol Parameter Condition Min Typ Max Units Bandgap startup time As reference for ADC or DAC 1 Clk_PER + 2.5µs µs Bandgap voltage 1.1 V[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 79 8067O–AVR–06/2013 34.9 Brownout Detection Characteristics Table 34-10. Brownout Detection characteristics. Note: 1. BOD is calibrated to BOD level 0 at 85°C, and BOD level 0 is the default level. 34.10 PAD Characteristics Table 34-11. PAD characteristics. ADC/DAC ref T= 85°C, After calibration 0.99 1.01 V 1 Variation over voltage and temperature VCC = 1.6 - 3.6V, T = -40C to 85C ±5 % Symbol Parameter Condition Min Typ Max Units Symbol Parameter Condition Min Typ Max Units BOD level 0 falling Vcc 1.6 V BOD level 1 falling Vcc 1.9 BOD level 2 falling Vcc 2.1 BOD level 3 falling Vcc 2.4 BOD level 4 falling Vcc 2.6 BOD level 5 falling Vcc 2.9 BOD level 6 falling Vcc 3.2 BOD level 7 falling Vcc 3.4 Hysteresis BOD level 0-5 2 % Symbol Parameter Condition Min Typ Max Units VIH Input High Voltage VCC = 2.4 - 3.6V 0.7*VCC VCC+0.5 V VCC = 1.6 - 2.4V 0.8*VCC VCC+0.5 VIL Input Low Voltage VCC = 2.4 - 3.6V -0.5 0.3*VCC V VCC = 1.6 - 2.4V -0.5 0.2*VCC VOL Output Low Voltage GPIO IOL = 15 mA, VCC = 3.3V 0.45 0.76 IOL = 10 mA, VCC = 3.0V 0.3 0.64 V IOL= 5 mA, VCC = 1.8V 0.2 0.46[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 80 8067O–AVR–06/2013 34.11 POR Characteristics Table 34-12. Power-on Reset characteristics. 34.12 Reset Characteristics Table 34-13. Reset characteristics. 34.13 Oscillator Characteristics Table 34-14. Internal 32.768kHz oscillator characteristics. VOH Output High Voltage GPIO IOH = -8 mA, VCC = 3.3V 2.6 3 IOH = -6 mA, VCC = 3.0V 2.1 2.2 V IOH = -2 mA, VCC = 1.8V 1.4 1.6 IIL Input Leakage Current I/O pin <0.001 1 µA IIH Input Leakage Current I/O pin <0.001 1 µA RP I/O pin Pull/Buss keeper Resistor 20 k RRST Reset pin Pull-up Resistor 20 k Input hysteresis 0.5 V Symbol Parameter Condition Min Typ Max Units Symbol Parameter Condition Min Typ Max Units VPOT- POR threshold voltage falling Vcc 1 V VPOT+ POR threshold voltage rising Vcc 1.4 V Symbol Parameter Condition Min Typ Max Units Minimum reset pulse width 90 ns Reset threshold voltage VCC = 2.7 - 3.6V 0.45*VCC V VCC = 1.6 - 2.7V 0.42*VCC Symbol Parameter Condition Min Typ Max Units Accuracy T = 85C, VCC = 3V, After production calibration -0.5 0.5 %[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 81 8067O–AVR–06/2013 Table 34-15. Internal 2MHz oscillator characteristics. Table 34-16. Internal 32MHz oscillator characteristics. Table 34-17. Internal 32kHz, ULP oscillator characteristics. Table 34-18. Maximum load capacitance (CL) and ESR recommendation for 32.768kHz crystal. Table 34-19. Device wake-up time from sleep. Notes: 1. Non-prescaled System Clock source. 2. Time from pin change on external interrupt pin to first available clock cycle. Additional interrupt response time is minimum 5 system clock source cycles. Symbol Parameter Condition Min Typ Max Units Accuracy T = 85C, VCC = 3V, After production calibration -1.5 1.5 % DFLL Calibration step size T = 25C, VCC = 3V 0.175 % Symbol Parameter Condition Min Typ Max Units Accuracy T = 85C, VCC = 3V, After production calibration -1.5 1.5 % DFLL Calibration stepsize T = 25C, VCC = 3V 0.2 % Symbol Parameter Condition Min Typ Max Units Output frequency 32 kHz ULP OSC T = 85C, VCC = 3.0V 26 kHz Crystal CL [pF] Max ESR [k] 6.5 60 9 35 Symbol Parameter Condition(1) Min Typ(2) Max Units Idle Sleep, Standby and Extended Standby sleep mode Int. 32.768 kHz RC 130 µS Int. 2 MHz RC 2 Ext. 2 MHz Clock 2 Int. 32 MHz RC 0.17 Power-save and Power-down Sleep mode Int. 32.768 kHz RC 320 Int. 2 MHz RC 10.3 Ext. 2 MHz Clock 4.5 Int. 32 MHz RC 5.8[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 82 8067O–AVR–06/2013 35. Typical Characteristics 35.1 Active Supply Current Figure 35-1. Active Supply Current vs. Frequency fSYS = 1 - 32 MHz, T = 25°C Figure 35-2. Active Supply Current vs. VCC fSYS = 1.0 MHz 3.3V 3.0V 2.7V 0 5 10 15 20 25 0 4 8 12 16 20 24 28 32 Frequency [MHz] Icc [mA] 1.8V 2.2V 85°C 25°C -40°C 0 200 400 600 800 1000 1200 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Icc [uA][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 83 8067O–AVR–06/2013 35.2 Idle Supply Current Figure 35-3. Idle Supply Current vs. Frequency fSYS = 1 - 32 MHz, T = 25°C Figure 35-4. Active Supply Current vs. VCC fSYS = 1.0 MHz , 3.3V 3.0V 2.7V 0 1 2 3 4 5 6 7 8 9 10 0 4 8 12 16 20 24 28 32 Frequency [MHz] Icc [mA] 1.8V 2.2V 85°C 25°C -40°C 0 50 100 150 200 250 300 350 400 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Icc [uA][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 84 8067O–AVR–06/2013 35.3 Power-down Supply Current Figure 35-5. Power-down Supply Current vs. Temperature 35.4 Power-save Supply Current Figure 35-6. Power-save Supply Current vs. Temperature Sampled BOD, WDT, RTC from ULP enabled 3.3V 3.0V 2.7V 2.2V 1.8V 0 0.5 1 1.5 2 2.5 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature [°C] Icc [uA] 3.3V 2.7V 2.2V 1.8V 0 0.5 1 1.5 2 2.5 3 3.5 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature [°C] Icc [uA][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 85 8067O–AVR–06/2013 35.5 Pin Pull-up Figure 35-7. I/O Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 1.8V Figure 35-8. I/O Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 3.0V 85 °C 25 °C -40 °C 0 20 40 60 80 100 0 0.2 0.4 0.6 0.8 1 1.2 1.4 vreset [V] Ireset [uA] 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 140 160 180 0 0.5 1 1.5 2 2.5 vreset [V] Ireset [uA][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 86 8067O–AVR–06/2013 Figure 35-9. I/O Reset Pull-up Resistor Current vs. Reset Pin Voltage VCC = 3.3V 35.6 Pin Thresholds and Hysteresis Figure 35-10.I/O Pin Input Threshold Voltage vs. VCC VIH - I/O Pin Read as “1” 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 140 160 180 0 0.5 1 1.5 2 2.5 3 vreset [V] Ireset [uA] 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Vthreshold [V][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 87 8067O–AVR–06/2013 Figure 35-11.I/O Pin Input Threshold Voltage vs. VCC VIL - I/O Pin Read as “0” Figure 35-12.I/O Pin Input Hysteresis vs. VCC. 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Vthreshold [V] 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Vthreshold [V][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 88 8067O–AVR–06/2013 Figure 35-13.Reset Input Threshold Voltage vs. VCC VIH - I/O Pin Read as “1” Figure 35-14.Reset Input Threshold Voltage vs. VCC VIL - I/O Pin Read as “0” 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Vthreshold [V] 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Vthreshold [V][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 89 8067O–AVR–06/2013 35.7 Bod Thresholds Figure 35-15.BOD Thresholds vs. Temperature BOD Level = 1.6V Figure 35-16.BOD Thresholds vs. Temperature BOD Level = 2.9V Rising Vcc Falling Vcc 1.602 1.608 1.614 1.62 1.626 1.632 1.638 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature [°C] VBOT [V] Rising Vcc Falling Vcc 2.905 2.92 2.935 2.95 2.965 2.98 2.995 3.01 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature [°C] VBOT [V][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 90 8067O–AVR–06/2013 35.8 Bandgap Figure 35-17.Internal 1.00V Reference vs. Temperature. 35.9 Analog Comparator Figure 35-18.Analog Comparator Hysteresis vs. VCC High-speed, Small hysteresis 3.0V 1.8V 0.999 0.9995 1 1.0005 1.001 1.0015 1.002 1.0025 1.003 1.0035 1.004 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature [°C] VREF [V] 25°C 0 5 10 15 20 25 30 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Hysteresis [mV][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 91 8067O–AVR–06/2013 Figure 35-19.Analog Comparator Hysteresis vs. VCC, High-speed Large hysteresis Figure 35-20.Analog Comparator Propagation Delay vs. VCC High-speed 25°C 0 10 20 30 40 50 60 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Hysteresis [mV] 25°C 0 20 40 60 80 100 120 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Vcc [V] Propagation Delay [ns][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 92 8067O–AVR–06/2013 35.10 Oscillators and Wake-up Time Figure 35-21.Internal 32.768 kHz Oscillator Frequency vs. Temperature 1.024 kHz output Figure 35-22.Ultra Low-Power (ULP) Oscillator Frequency vs. Temperature 1 kHz output p 3.0 V 1.8 V 0.99 0.995 1 1.005 1.01 1.015 1.02 1.025 1.03 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 T [°C] f [kHz] p 3.0 V 1.8 V 0.87 0.88 0.89 0.9 0.91 0.92 0.93 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 T [°C] f1kHz output [kHz][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 93 8067O–AVR–06/2013 Figure 35-23.Internal 2 MHz Oscillator CalA Calibration Step Size T = -40 to 85C, VCC = 3V Figure 35-24.Internal 2 MHz Oscillator CalB Calibration Step Size T = -40 to 85C, VCC = 3V 0 0.001 0.002 0.003 0.004 0.005 0.006 0 20 40 60 80 100 120 140 CALA [LSB] Step size: f [MHz] 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0 10 20 30 40 50 60 70 CALB [LSB] Step size: f [MHz][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 94 8067O–AVR–06/2013 Figure 35-25.Internal 32 MHz Oscillator CalA Calibration Step Size T = -40 to 85C, VCC = 3V Figure 35-26.Internal 32 MHz Oscillator CalB Calibration Step Size T = -40 to 85C, VCC = 3V 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0 20 40 60 80 100 120 140 CALA Step size: f [MHz] 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 10 20 30 40 50 60 70 CALB Step size: f [MHz][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 95 8067O–AVR–06/2013 35.11 PDI Speed Figure 35-27.PDI Speed vs. VCC 25 °C 0 5 10 15 20 25 30 35 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 VCC [V] fMAX [MHz][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 96 8067O–AVR–06/2013 36. Errata 36.1 ATxmega64A1and ATxmega128A1 rev. H  Bandgap voltage input for the ACs can not be changed when used for both ACs simultaneously  VCC voltage scaler for AC is non-linear  The ADC has up to ±2 LSB inaccuracy  ADC gain stage output range is limited to 2.4 V  Sampling speed limited to 500 ksps for supply voltage below 2.0V  ADC Event on compare match non-functional  Bandgap measurement with the ADC is non-functional when VCC is below 2.7V  Accuracy lost on first three samples after switching input to ADC gain stage  The input difference between two succeeding ADC samples is limited by VREF  Increased noise when using internal 1.0V reference at low temperature  Configuration of PGM and CWCM not as described in XMEGA A Manual  PWM is not restarted properly after a fault in cycle-by-cycle mode  BOD will be enabled at any reset  BODACT fuse location is not correct  Sampled BOD in Active mode will cause noise when bandgap is used as reference  DAC has up to ±10 LSB noise in Sampled Mode  DAC is nonlinear and inaccurate when reference is above 2.4V or VCC - 0.6V  DAC refresh may be blocked in S/H mode  Conversion lost on DAC channel B in event triggered mode  Both DFLLs and both oscillators have to be enabled for one to work  Access error when multiple bus masters are accessing SDRAM  EEPROM page buffer always written when NVM DATA0 is written  Pending full asynchronous pin change interrupts will not wake the device  Pin configuration does not affect Analog Comparator Output  Low level interrupt triggered when pin input is disabled  JTAG enable does not override Analog Comparator B output  NMI Flag for Crystal Oscillator Failure automatically cleared  Flash Power Reduction Mode can not be enabled when entering sleep  Some NVM Commands are non-functional  Crystal start-up time required after power-save even if crystal is source for RTC  Setting PRHIRES bit makes PWM output unavailable  Accessing EBI address space with PREBI set will lock Bus Master  RTC Counter value not correctly read after sleep  Pending asynchronous RTC-interrupts will not wake up device  TWI, the minimum I2C SCL low time could be violated in Master Read mode  TWI address-mask feature is non-functional  TWI, a general address call will match independent of the R/W-bit value  TWI Transmit collision flag not cleared on repeated start  Clearing TWI Stop Interrupt Flag may lock the bus[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 97 8067O–AVR–06/2013  TWI START condition at bus timeout will cause transaction to be dropped  TWI Data Interrupt Flag erroneously read as set  WDR instruction inside closed window will not issue reset 1. Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously If the Bandgap voltage is selected as input for one Analog Comparator (AC) and then selected/deselected as input for another AC, the first comparator will be affected for up to 1 µs and could potentially give a wrong comparison result. Problem fix/Workaround If the Bandgap is required for both ACs simultaneously, configure the input selection for both ACs before enabling any of them. 2. VCC voltage scaler for AC is non-linear The 6-bit VCC voltage scaler in the Analog Comparators is non-linear. Figure 36-1. Analog Comparator Voltage Scaler vs. Scalefac T = 25°C Problem fix/Workaround Use external voltage input for the analog comparator if accurate voltage levels are needed 3. The ADC has up to ±2 LSB inaccuracy The ADC will have up to ±2 LSB inaccuracy, visible as a saw-tooth pattern on the input voltage/ output value transfer function of the ADC. The inaccuracy increases with increasing voltage reference reaching ±2 LSB with 3V reference. 3.3 V 2.7 V 1.8 V 0 0.5 1 1.5 2 2.5 3 3.5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 SCALEFAC VSCALE [V][Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 98 8067O–AVR–06/2013 Problem fix/Workaround None, the actual ADC resolution will be reduced with up to ±2 LSB. 4. ADC gain stage output range is limited to 2.4 V The amplified output of the ADC gain stage will never go above 2.4 V, hence the differential input will only give correct output when below 2.4 V/gain. For the available gain settings, this gives a differential input range of: Problem fix/Workaround Keep the amplified voltage output from the ADC gain stage below 2.4 V in order to get a correct result, or keep ADC voltage reference below 2.4 V. 5. Sampling speed limited to 500 ksps for supply voltage below 2.0V The sampling frequency is limited to 500 ksps for supply voltage below 2.0V. At higher sampling rate the INL error will be several hundred LSB. Problem fix/Workaround None. 6. ADC Event on compare match non-functional ADC signalling event will be given at every conversion complete even if Interrupt mode (INTMODE) is set to BELOW or ABOVE. Problem fix/Workaround Enable and use interrupt on compare match when using the compare function. 7. Bandgap measurement with the ADC is non-functional when VCC is below 2.7V The ADC can not be used to do bandgap measurements when VCC is below 2.7V. Problem fix/Workaround – 1x gain: 2.4 V – 2x gain: 1.2 V – 4x gain: 0.6 V – 8x gain: 300 mV – 16x gain: 150 mV – 32x gain: 75 mV – 64x gain: 38 mV[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 99 8067O–AVR–06/2013 None. 8. Accuracy lost on first three samples after switching input to ADC gain stage Due to memory effect in the ADC gain stage, the first three samples after changing input channel must be disregarded to achieve 12-bit accuracy. Problem fix/Workaround Run three ADC conversions and discard these results after changing input channels to ADC gain stage. 9. The input difference between two succeeding ADC samples is limited by VREF If the difference in input between two samples changes more than the size of the reference, the ADC will not be able to convert the data correctly. Two conversions will be required before the conversion is correct. Problem fix/Workaround Discard the first conversion if input is changed more than VREF, or ensure that the input never changes more then VREF. 10. Increased noise when using internal 1.0V reference at low temperature When operating at below 0C and using internal 1.0V reference the RMS noise will be up 4 LSB, Peak-to-peak noise up to 25 LSB. Problem fix/Workaround Use averaging to remove noise. 11. Configuration of PGM and CWCM not as described in XMEGA A Manual Enabling Common Waveform Channel Mode will enable Pattern generation mode (PGM), but not Common Waveform Channel Mode. Enabling Pattern Generation Mode (PGM) and not Common Waveform Channel Mode (CWCM) will enable both Pattern Generation Mode and Common Waveform Channel Mode. Problem fix/Workaround 12 PWM is not restarted properly after a fault in cycle-by-cycle mode When the AWeX fault restore mode is set to cycle-by-cycle, the waveform output will not return to normal operation at first update after fault condition is no longer present. PGM CWCM Description 0 0 PGM and CWCM disabled 0 1 PGM enabled 1 0 PGM and CWCM enabled 1 1 PGM enabled[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 100 8067O–AVR–06/2013 Problem fix/Workaround Do a write to any AWeX I/O register to re-enable the output. 13. BOD will be enabled after any reset If any reset source goes active, the BOD will be enabled and keep the device in reset if the VCC voltage is below the programmed BOD level. During Power-On Reset, reset will not be released until VCC is above the programmed BOD level even if the BOD is disabled. Problem fix/Workaround Do not set the BOD level higher than VCC even if the BOD is not used. 14. BODACT fuse location is not correct The fuses for enabling BOD in active mode (BODACT) are located at FUSEBYTE2, bit 2 and 3 and not in FUSEBYTE 5 as described in the XMEGA A Manual. Problem fix/Workaround Access the fuses in FUSEBYTE2. 15. Sampled BOD in Active mode will cause noise when bandgap is used as reference Using the BOD in sampled mode when the device is running in Active or Idle mode will add noise on the bandgap reference for ADC, DAC and Analog Comparator. Problem fix/Workaround If the bandgap is used as reference for either the ADC, DAC or Analog Comparator, the BOD must not be set in sampled mode. 16. DAC has up to ±10 LSB noise in Sampled Mode The DAC has noise of up to ±10 LSB in Sampled Mode for entire operation range. Problem fix/Workaround Use the DAC in continuous mode. 17. DAC is nonlinear and inaccurate when reference is above 2.4V or VCC - 0.6V Using the DAC with a reference voltage above 2.4V or VCC - 0.6V will give inaccurate output when converting codes that give below 0.75V output:  ±10 LSB for continuous mode  ±200 LSB for Sample and Hold mode Problem fix/Workaround None.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 101 8067O–AVR–06/2013 18. DAC has up to ±10 LSB noise in Sampled Mode If the DAC is running in Sample and Hold (S/H) mode and conversion for one channel is done at maximum rate (i.e. the DAC is always busy doing conversion for this channel), this will block refresh signals to the second channel. Problem fix/Workaround When using the DAC in S/H mode, ensure that none of the channels is running at maximum conversion rate, or ensure that the conversion rate of both channels is high enough to not require refresh. 19. Conversion lost on DAC channel B in event triggered mode If during dual channel operation channel 1 is set in auto trigged conversion mode, channel 1 conversions are occasionally lost. This means that not all data-values written to the Channel 1 data register are converted. Problem fix/Workaround Keep the DAC conversion interval in the range 000-001 (1 and 3 CLK), and limit the Peripheral clock frequency so the conversion internal never is shorter than 1.5 µs. 20. Both DFLLs and both oscillators have to be enabled for one to work In order to use the automatic runtime calibration for the 2 MHz or the 32 MHz internal oscillators, the DFLL for both oscillators and both oscillators have to be enabled for one to work. Problem fix/Workaround Enable both DFLLs and both oscillators when using automatic runtime calibration for either of the internal oscillators. 21. Access error when multiple bus masters are accessing SDRAM If one bus master (CPU and DMA channels) is using the EBI to access an SDRAM in burst mode and another bus master is accessing the same row number in a different BANK of the SDRAM in the cycle directly after the burst access is complete, the access for the second bus master will fail. Problem fix/Workaround Do not put stack pointer in SDRAM and use DMA Controller in 1 byte burst mode if CPU and DMA Controller are required to access SDRAM at the same time. 22. EEPROM page buffer always written when NVM DATA0 is written If the EEPROM is memory mapped, writing to NVM DATA0 will corrupt data in the EEPROM page buffer. Problem fix/Workaround Before writing to NVM DATA0, for example when doing software CRC or flash page buffer write, check if EEPROM page buffer active loading flag (EELOAD) is set. Do not write NVM DATA0 when EELOAD is set. 23. Pending full asynchronous pin change interrupts will not wake the device[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 102 8067O–AVR–06/2013 Any full asynchronous pin-change Interrupt from pin 2, on any port, that is pending when the sleep instruction is executed, will be ignored until the device is woken from another source or the source triggers again. This applies when entering all sleep modes where the System Clock is stopped. Problem fix/Workaround None. 24. Pin configuration does not affect Analog Comparator Output The Output/Pull and inverted pin configuration does not affect the Analog Comparator output function. Problem fix/Workaround None for Output/Pull configuration. For inverted I/O, configure the Analog Comparator to give an inverted result (i.e. connect positive input to the negative AC input and vice versa), or use and external inverter to change polarity of Analog Comparator output. 25. Low level interrupt triggered when pin input is disabled If a pin input is disabled, but pin is configured to trigger on low level, interrupt request will be sent. Problem fix/Workaround Ensure that Interrupt mask for the disabled pin is cleared. 26. JTAG enable does not override Analog Comparator B output When JTAG is enabled this will not override the Analog Comparator B (ACB) output, AC0OUT on pin 7 if this is enabled. Problem fix/Workaround Use Analog Comparator output for ACA when JTAG is used, or use the PDI as debug interface. 27. NMI Flag for Crystal Oscillator Failure automatically cleared NMI flag for Crystal Oscillator Failure (XOSCFDIF) will be automatically cleared when executing the NMI interrupt handler. Problem fix/Workaround This device revision has only one NMI interrupt source, so checking the interrupt source in software is not required. 28. Flash Power Reduction Mode can not be enabled when entering sleep If Flash Power Reduction Mode is enabled when entering Power-save or Extended Standby sleep mode, the device will only wake up on every fourth wake-up request. If Flash Power Reduction Mode is enabled when entering Idle sleep mode, the wake-up time will vary with up to 16 CPU clock cycles.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 103 8067O–AVR–06/2013 Problem fix/Workaround Disable Flash Power Reduction mode before entering sleep mode. 29. Some NVM Commands are non-functional The following NVM commands are non-functional: Problem fix/Workaround None for Flash Range CRC Use separate programming commands for accessing application and boot section. 30. Crystal start-up time required after power-save even if crystal is source for RTC Even if 32.768 kHz crystal is used for RTC during sleep, the clock from the crystal will not be ready for the system before the specified start-up time. See "XOSCSEL[3:0]: Crystal Oscillator Selection" in XMEGA A Manual. If BOD is used in active mode, the BOD will be on during this period (0.5s). Problem fix/Workaround If faster start-up is required, go to sleep with internal oscillator as system clock. 31. Setting PRHIRES bit makes PWM output unavailable Setting the HIRES Power Reduction (PR) bit for PORTx will make any Frequency or PWM output for the corresponding Timer/Counters (TCx0 and TCx1) unavailable on the pin even if the Hi-Res is not used. Problem fix/Workaround Do not write the HIRES PR bit on PORTx when frequency or PWM output from TCx0/1 is used. – 0x2B Erase Flash Page – 0x2E Write Flash Page – 0x2F Erase & Write Flash Page – 0x3A Flash Range CRC – 0x22 Erase Application Section Page – 0x24 Write Application Section Page – 0x25 Erase & Write Application Section Page – 0x2A Erase Boot Loader Section Page – 0x2C Write Boot Loader Section Page – 0x2D Erase & Write Boot Loader Section Page[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 104 8067O–AVR–06/2013 32. Accessing EBI address space with PREBI set will lock Bus Master If EBI Power Reduction Bit is set while EBI is enabled, accessing external memory could result in bus hang-up, blocking all further access to all data memory. Problem fix/Workaround Ensure that EBI is disabled before setting EBI Power Reduction bit. 33. RTC Counter value not correctly read after sleep If the RTC is set to wake up the device on RTC Overflow and bit 0 of RTC CNT is identical to bit 0 of RTC PER as the device is entering sleep, the value in the RTC count register can not be read correctly within the first prescaled RTC clock cycle after wakeup. The value read will be the same as the value in the register when entering sleep. The same applies if RTC Compare Match is used as wake-up source. Problem fix/Workaround Wait at least one prescaled RTC clock cycle before reading the RTC CNT value. 34. Pending asynchronous RTC-interrupts will not wake up device Asynchronous Interrupts from the Real-Time-Counter that is pending when the sleep instruction is executed, will be ignored until the device is woken from another source or the source triggers again. Problem fix/Workaround None. 35. TWI, the minimum I2 C SCL low time could be violated in Master Read mode If the TWI is in Master Read mode and issues a Repeated Start on the bus, this will immediately release the SCL line even if one complete SCL low period has not passed. This means that the minimum SCL low time in the I2C specification could be violated. Problem fix/Workaround If this is a problem in the application, ensure in software that the Repeated Start is never issued before one SCL low time has passed. 36. TWI address-mask feature is non-functional The address-mask feature is non-functional, so the TWI can not perform hardware address match on more than one address. Problem fix/Workaround If the TWI must respond to multiple addresses, enable Promiscuous Mode for the TWI to respond to all address and implement the address-mask function in software.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 105 8067O–AVR–06/2013 37. TWI, a general address call will match independent of the R/W-bit value When the TWI is in Slave mode and a general address call is issued on the bus, the TWI Slave will get an address match regardless of the received R/W bit. Problem fix/Workaround Use software to check the R/W-bit on general call address match. 38. TWI Transmit collision flag not cleared on repeated start The TWI transmit collision flag should be automatically cleared on start and repeated start, but is only cleared on start. Problem fix/Workaround Clear the flag in software after address interrupt. 39. Clearing TWI Stop Interrupt Flag may lock the bus If software clears the STOP Interrupt Flag (APIF) on the same Peripheral Clock cycle as the hardware sets this flag due to a new address received, CLKHOLD is not cleared and the SCL line is not released. This will lock the bus. Problem fix/Workaround Check if the bus state is IDLE. If this is the case, it is safe to clear APIF. If the bus state is not IDLE, wait for the SCL pin to be low before clearing APIF. Code: /* Only clear the interrupt flag if within a "safe zone". */ while ( /* Bus not IDLE: */ ((COMMS_TWI.MASTER.STATUS & TWI_MASTER_BUSSTATE_gm) != TWI_MASTER_BUSSTATE_IDLE_gc)) && /* SCL not held by slave: */ !(COMMS_TWI.SLAVE.STATUS & TWI_SLAVE_CLKHOLD_bm) ) { /* Ensure that the SCL line is low */ if ( !(COMMS_PORT.IN & PIN1_bm) ) if ( !(COMMS_PORT.IN & PIN1_bm) ) break; } /* Check for an pending address match interrupt */ if ( !(COMMS_TWI.SLAVE.STATUS & TWI_SLAVE_CLKHOLD_bm) ) { /* Safely clear interrupt flag */ COMMS_TWI.SLAVE.STATUS |= (uint8_t)TWI_SLAVE_APIF_bm; }[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 106 8067O–AVR–06/2013 40. TWI START condition at bus timeout will cause transaction to be dropped If Bus Timeout is enabled and a timeout occurs on the same Peripheral Clock cycle as a START is detected, the transaction will be dropped. Problem fix/Workaround None. 41. TWI Data Interrupt Flag erroneously read as set When issuing the TWI slave response command CMD=0b11, it takes 1 Peripheral Clock cycle to clear the data interrupt flag (DIF). A read of DIF directly after issuing the command will show the DIF still set. Problem fix/Workaround Add one NOP instruction before checking DIF. 42. WDR instruction inside closed window will not issue reset When a WDR instruction is execute within one ULP clock cycle after updating the window control register, the counter can be cleared without giving a system reset. Problem fix/Workaround Wait at least one ULP clock cycle before executing a WDR instruction.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 107 8067O–AVR–06/2013 36.2 ATxmega64A1 and ATxmega128A1 rev. G  Bootloader Section in Flash is non-functional  Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously  DAC is nonlinear and inaccurate when reference is above 2.4V  ADC gain stage output range is limited to 2.4 V  The ADC has up to ±2 LSB inaccuracy  TWI, a general address call will match independent of the R/W-bit value  TWI, the minimum I2 C SCL low time could be violated in Master Read mode  Setting HIRES PR bit makes PWM output unavailable  EEPROM erase and write does not work with all System Clock sources  BOD will be enabled after any reset  Propagation delay analog Comparator increasing to 2 ms at -40C  Sampled BOD in Active mode will cause noise when bandgap is used as reference  Default setting for SDRAM refresh period too low  Flash Power Reduction Mode can not be enabled when entering sleep mode  Enabling Analog Comparator B output will cause JTAG failure  JTAG enable does not override Analog Comparator B output  Bandgap measurement with the ADC is non-functional when VCC is below 2.7V  DAC refresh may be blocked in S/H mode  Inverted I/O enable does not affect Analog Comparator Output  Both DFLLs and both oscillators has to be enabled for one to work 1. Bootloader Section in Flash is non-functional The Bootloader Section is non-functional, and bootloader or application code cannot reside in this part of the Flash. Problem fix/Workaround None, do not use the Bootloader Section. 2. Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously If the Bandgap voltage is selected as input for one Analog Comparator (AC) and then selected/deselected as input for the another AC, the first comparator will be affected for up to 1 us and could potentially give a wrong comparison result. Problem fix/Workaround If the Bandgap is required for both ACs simultaneously, configure the input selection for both ACs before enabling any of them. 3. DAC is nonlinear and inaccurate when reference is above 2.4V Using the DAC with a reference voltage above 2.4V give inaccurate output when converting codes that give below 0.75V output:  ±20 LSB for continuous mode[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 108 8067O–AVR–06/2013  ±200 LSB for Sample and Hold mode Problem fix/Workaround None, avoid using a voltage reference above 2.4V. 4. ADC gain stage output range is limited to 2.4 V The amplified output of the ADC gain stage will never go above 2.4 V, hence the differential input will only give correct output when below 2.4 V/gain. For the available gain settings, this gives a differential input range of: Problem fix/Workaround Keep the amplified voltage output from the ADC gain stage below 2.4 V in order to get a correct result, or keep ADC voltage reference below 2.4 V. 5. The ADC has up to ±2 LSB inaccuracy The ADC will have up to ±2 LSB inaccuracy, visible as a saw-tooth pattern on the input voltage/ output value transfer function of the ADC. The inaccuracy increases with increasing voltage reference reaching ±2 LSB with 3V reference. Problem fix/Workaround None, the actual ADC resolution will be reduced with up to ±2 LSB. 6. TWI, a general address call will match independent of the R/W-bit value When the TWI is in Slave mode and a general address call is issued on the bus, the TWI Slave will get an address match regardless of the R/W-bit (ADDR[0] bit) value in the Slave Address Register. Problem fix/Workaround Use software to check the R/W-bit on general call address match. – 1x gain: 2.4 V – 2x gain: 1.2 V – 4x gain: 0.6 V – 8x gain: 300 mV – 16x gain: 150 mV – 32x gain: 75 mV – 64x gain: 38 mV[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 109 8067O–AVR–06/2013 7. TWI, the minimum I2 C SCL low time could be violated in Master Read mode When the TWI is in Master Read mode and issuing a Repeated Start on the bus, this will immediately release the SCL line even if one complete SCL low period has not passed. This means that the minimum SCL low time in the I 2 C specification could be violated. Problem fix/Workaround If this causes a potential problem in the application, software must ensure that the Repeated Start is never issued before one SCL low time has passed. 8. Setting HIRES PR bit makes PWM output unavailable Setting the HIRES Power Reduction (PR) bit for PORTx will make any Frequency or PWM output for the corresponding Timer/Counters (TCx0 and TCx1) unavailable on the pin. Problem fix/Workaround Do not write the HIRES PR bit on PORTx when frequency or PWM output from TCx0/1 is used. 9. EEPROM erase and write does not work with all System Clock sources When doing EEPROM erase or Write operations with other clock sources than the 2 MHz RCOSC, Flash will be read wrongly for one or two clock cycles at the end of the EEPROM operation. Problem fix/Workaround Alt 1: Use the internal 2 MHz RCOSC when doing erase or write operations on EEPROM. Alt 2: Ensure to be in sleep mode while completing erase or write on EEPROM. After starting erase or write operations on EEPROM, other interrupts should be disabled and the device put to sleep. 10. BOD will be enabled after any reset If any reset source goes active, the BOD will be enabled and keep the device in reset if the VCC voltage is below the programmed BOD level. During Power-On Reset, reset will not be released until VCC is above the programmed BOD level even if the BOD is disabled. Problem fix/Workaround Do not set the BOD level higher than VCC even if the BOD is not used. 11. Propagation delay analog Comparator increasing to 2 ms at -40 °C When the analog comparator is used at temperatures reaching down to -40 °C, the propagation delay will increase to ~2 ms. Problem fix/Workaround None[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 110 8067O–AVR–06/2013 12. Sampled BOD in Active mode will cause noise when bandgap is used as reference Using the BOD in sampled mode when the device is running in Active or Idle mode will add noise on the bandgap reference for ADC and DAC. Problem fix/Workaround If the bandgap is used as reference for either the ADC or the DAC, the BOD must not be set in sampled mode. 13. Default setting for SDRAM refresh period too low If the SDRAM refresh period is set to a value less then 0x20, the SDRAM content may be corrupted when accessing through On-Chip Debug sessions. Problem fix/Workaround The SDRAM refresh period (REFRESHH/L) should not be set to a value less then 0x20. 14. Flash Power Reduction Mode can not be enabled when entering sleep mode If Flash Power Reduction Mode is enabled when entering Power-save or Extended Standby sleep mode, the device will only wake up on every fourth wake-up request. If Flash Power Reduction Mode is enabled when entering Idle sleep mode, the wake-up time will vary with up to 16 CPU clock cycles. Problem fix/Workaround Disable Flash Power Reduction mode before entering sleep mode. 15. JTAG enable does not override Analog Comparator B output When JTAG is enabled this will not override the Anlog Comparator B (ACB)ouput, AC0OUT on pin 7 if this is enabled. Problem fix/Workaround AC0OUT for ACB should not be enabled when JTAG is used. Use only analog comparator output for ACA when JTAG is used, or use the PDI as debug interface. 16. Bandgap measurement with the ADC is non-functional when VCC is below 2.7V The ADC cannot be used to do bandgap measurements when VCC is below 2.7V. Problem fix/Workaround If internal voltages must be measured when VCC is below 2.7V, measure the internal 1.00V reference instead of the bandgap.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 111 8067O–AVR–06/2013 17. DAC refresh may be blocked in S/H mode If the DAC is running in Sample and Hold (S/H) mode and conversion for one channel is done at maximum rate (i.e. the DAC is always busy doing conversion for this channel), this will block refresh signals to the second channel. Problem fix/Workarund When using the DAC in S/H mode, ensure that none of the channels is running at maximum conversion rate, or ensure that the conversion rate of both channels is high enough to not require refresh. 18. Inverted I/O enable does not affect Analog Comparator Output The inverted I/O pin function does not affect the Analog Comparator output function. Problem fix/Workarund Configure the analog comparator setup to give a inverted result (i.e. connect positive input to the negative AC input and vice versa), or use and externel inverter to change polarity of Analog Comparator Output. 19. Both DFLLs and both oscillators has to be enabled for one to work In order to use the automatic runtime calibration for the 2 MHz or the 32 MHz internal oscilla-tors, the DFLL for both oscillators and both oscillators has to be enabled for one to work. Problem fix/Workarund Enabled both DFLLs and oscillators when using automatic runtime calibration for one of the internal oscillators. [Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 112 8067O–AVR–06/2013 37. Datasheet Revision History Please note that the referring page numbers in this section are referred to this document. The referring revision in this section are referring to the document revision. 37.1 8067O – 06/2013 37.2 8067N – 03/2013 37.3 8067M – 09/2010 37.4 8067L – 08/2010 1. Not recommended for new designs - Use XMEGA A1U series. 1. Removed all references to ATxmega192A1, ATxmega256A1 and ATxmega384A1. 2. Updated module description. Based on the XMEGA A1U device datasheet. 3. Updated analog comparator (AC) overview, Figure 28-1 on page 53. 4. Updated “ADC Characteristics” on page 76. 5 Updated page erase time in “Flash and EEPROM Memory Characteristics” on page 76. 6 Updated Output low voltage conditions from IOH to IOL in “PAD Characteristics” on page 79. 7. Removed TBDs from: “DC Characteristics” on page 73. “DAC Characteristics” on page 78. “Bandgap Characteristics” on page 78. 8. Updated “Errata” on page 96 to be valid for both ATxmega64A1 and ATxmega128A1. 9. Removed Boundary Scan Order table. 1. Updated Errata “ATxmega64A1and ATxmega128A1 rev. H” on page 96 1. Removed Footnote 3 of Figure 2-1 on page 3 2. Updated “Features” on page 32. Event Channel 0 output on port pin 7 3. Updated “DC Characteristics” on page 73, by adding ICC for Flash/EEPROM Programming. 4. Added AVCC in “ADC Characteristics” on page 76. 5. Updated Start up time in “ADC Characteristics” on page 76. [Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 113 8067O–AVR–06/2013 37.5 8067K – 02/2010 37.6 8067J – 02/2010 37.7 8067I – 04/2009 37.8 8067H – 04/2009 6. Updated “DAC Characteristics” on page 78. Removed DC output impedance. 7. Fixed typo in “Packaging information” section. 8. Fixed typo in “Errata” section. 1. Added “PDI Speed vs. VCC” on page 95. 1. Removed JTAG Reset from the datasheet. 2. Updated “Timer/Counter and AWEX functions” on page 56. 3. Updated “Alternate Pin Functions” on page 58. 3. Updated all “Electrical Characteristics” on page 73. 4. Updated “PAD Characteristics” on page 79. 5. Changed Internal Oscillator Speed to “Oscillators and Wake-up Time” on page 92. 6. Updated “Errata” on page 96 1. Updated “Ordering Information” on page 2. 2. Updated “PAD Characteristics” on page 79. 1. Editorial updates. 2. Updated “Overview” on page 54. 3. Updated Table 29-9 on page 54. 4. Updated “Peripheral Module Address Map” on page 62. IRCOM has address map: 0x08F8. 5. Updated “Electrical Characteristics” on page 73. 6. Updated “PAD Characteristics” on page 79. 7. Updated “Typical Characteristics” on page 82.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 114 8067O–AVR–06/2013 37.9 8067G – 11/2008 37.10 8067F – 09/2008 37.11 8067E – 08/2008 37.12 8067D – 07/2008 1. Updated “Block Diagram” on page 6. 2. Updated feature list in “Memories” on page 12. 3. Updated “Programming and Debugging” on page 54. 4. Updated “Peripheral Module Address Map” on page 62. IRCOM has address 0x8F0. 5. Added “Electrical Characteristics” on page 73. 6. Added “Typical Characteristics” on page 82. 7. Added “ATxmega64A1and ATxmega128A1 rev. H” on page 96. 8. Updated “ATxmega64A1 and ATxmega128A1 rev. G” on page 107. 1. Updated “Features” on page 1 2. Updated “Ordering Information” on page 2 3. Updated Figure 7-1 on page 11 and Figure 7-2 on page 11. 4. Updated Table 7-2 on page 15. 5. Updated “Features” on page 48 and “Overview” on page 48. 6. Removed “Interrupt Vector Summary” section from datasheet. 1. Changed Figure 2-1’s title to “Block diagram and pinout” on page 3. 2. Updated Figure 2-2 on page 4. 3. Updated Table 29-2 on page 51 and Table 29-3 on page 52. 1. Updated “Ordering Information” on page 2. 2. Updated “Peripheral Module Address Map” on page 62. 3. Inserted “Interrupt Vector Summary” on page 56.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 115 8067O–AVR–06/2013 37.13 8067C – 06/2008 37.14 8067B – 05/2008 37.15 8067A – 02/2008 1. Updated the Front page and “Features” on page 1. 2. Updated the “DC Characteristics” on page 73. 3. Updated Figure 3-1 on page 6. 4. Added “Flash and EEPROM Page Size” on page 15. 5. Updated Table 33-6 on page 72 with new data: Gain Error, Offset Error and Signal -to-Noise Ratio (SNR). 6. Updated Errata “ATxmega64A1 and ATxmega128A1 rev. G” on page 107. 1. Updated “Pinout/Block Diagram” on page 3 and “Pinout and Pin Functions” on page 55. 2. Added XMEGA A1 Block Diagram, Figure 3-1 on page 6. 3. Updated “Overview” on page 5 included the XMEGA A1 explanation text on page 6. 4. Updated AVR CPU “Features” on page 8. 5. Updated Event System block diagram, Figure 10-1 on page 20. 6. Updated “Interrupts and Programmable Multilevel Interrupt Controller” on page 29. 7. Updated “AC - Analog Comparator” on page 52. 8. Updated “Alternate Pin Function Description” on page 55. 9. Updated “Alternate Pin Functions” on page 58. 10. Updated “Typical Characteristics” on page 82. 11. Updated “Ordering Information” on page 2. 12. Updated “Overview” on page 5. 13. Updated Figure 6-1 on page 8. 14. Inserted a new Figure 16-1 on page 37. 15. Updated Speed grades in “Speed” on page 75. 16. Added a new ATxmega384A1 device in “Features” on page 1, updated “Ordering Information” on page 2 and “Memories” on page 12. 17. Replaced the Figure 3-1 on page 6 by a new XMEGA A1 detailed block diagram. 18. Inserted Errata “ATxmega64A1 and ATxmega128A1 rev. G” on page 107. 1. Initial revision.[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 116 8067O–AVR–06/2013[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 1 8067O–AVR–06/2013 Table of Contents Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Pinout/Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1 Recommended reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Capacitive touch sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6. Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. AVR CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7.3 Architectural Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7.4 ALU - Arithmetic Logic Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.5 Program Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.6 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.7 Register File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8. Memories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.3 In-System Programmable Flash Program Memory. . . . . . . . . . . . . . . . . . . . . 13 8.4 Fuses and Lock bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 8.5 Data Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 8.6 EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.7 I/O Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.8 External Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.9 Data Memory and Bus Arbitration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.10 Memory Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8.11 Device ID and Revision. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8.12 I/O Memory Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8.13 JTAG Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8.14 Flash and EEPROM Page Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 9. DMAC - Direct Memory Access Controller . . . . . . . . . . . . . . . . . . . . 18 9.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 9.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 10. Event System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 11. System Clock and Clock options . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 11.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 11.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 2 8067O–AVR–06/2013 11.3 Clock Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 12. Power Management and Sleep Modes . . . . . . . . . . . . . . . . . . . . . . 24 12.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 12.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 12.3 Sleep Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 13. System Control and Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 13.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 13.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 13.3 Reset Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 13.4 Reset Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 13.5 WDT - Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 13.6 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 14. Interrupts and Programmable Multilevel Interrupt Controller . . . . . . 29 14.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 14.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 14.3 Interrupt vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 15. I/O Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 15.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 15.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 15.3 Output Driver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 15.4 Input sensing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 15.5 Port Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 15.6 Alternate Port Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 16. T/C - 16-bit Timer/Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 16.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 16.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 17. AWeX - Advanced Waveform Extension . . . . . . . . . . . . . . . . . . . . . 38 17.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 17.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 18. Hi-Res - High Resolution Extension . . . . . . . . . . . . . . . . . . . . . . . . . 39 18.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 18.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 19. RTC - 16-bit Real-Time Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 19.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 19.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 20. TWI - Two-Wire Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 20.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 20.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 21. SPI - Serial Peripheral Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 21.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 21.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 22. USART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 3 8067O–AVR–06/2013 22.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 22.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 23. IRCOM - IR Communication Module . . . . . . . . . . . . . . . . . . . . . . . . 45 23.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 23.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 24. AES and DES Crypto Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 24.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 24.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 25. EBI – External Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 25.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 25.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 26. ADC - 12-bit Analog to Digital Converter . . . . . . . . . . . . . . . . . . . . . 48 26.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 26.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 27. DAC - 12-bit Digital to Analog Converter . . . . . . . . . . . . . . . . . . . . . 50 27.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 27.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 28. AC - Analog Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 28.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 28.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 29. Programming and Debugging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 29.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 29.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 30. Pinout and Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 30.1 Alternate Pin Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 30.2 Alternate Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 31. Peripheral Module Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 32. Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 33. Packaging information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 33.1 100A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 33.2 100C1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 33.3 100C2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 34. Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 34.1 Absolute Maximum Ratings*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 34.2 DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 34.3 Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 34.4 Flash and EEPROM Memory Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . 76 34.5 ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 34.6 DAC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 34.7 Analog Comparator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 34.8 Bandgap Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 34.9 Brownout Detection Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 4 8067O–AVR–06/2013 34.10 PAD Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 34.11 POR Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 34.12 Reset Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 34.13 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 35. Typical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 35.1 Active Supply Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 35.2 Idle Supply Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 35.3 Power-down Supply Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 35.4 Power-save Supply Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 35.5 Pin Pull-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 35.6 Pin Thresholds and Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 35.7 Bod Thresholds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 35.8 Bandgap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 35.9 Analog Comparator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 35.10 Oscillators and Wake-up Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 35.11 PDI Speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 36. Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 36.1 ATxmega64A1and ATxmega128A1 rev. H. . . . . . . . . . . . . . . . . . . . . . . . . . . 96 36.2 ATxmega64A1 and ATxmega128A1 rev. G . . . . . . . . . . . . . . . . . . . . . . . . . 107 37. Datasheet Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 37.1 8067O – 06/2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 37.2 8067N – 03/2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 37.3 8067M – 09/2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 37.4 8067L – 08/2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 37.5 8067K – 02/2010. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 37.6 8067J – 02/2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 37.7 8067I – 04/2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 37.8 8067H – 04/2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 37.9 8067G – 11/2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 37.10 8067F – 09/2008. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 37.11 8067E – 08/2008. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 37.12 8067D – 07/2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 37.13 8067C – 06/2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 37.14 8067B – 05/2008. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 37.15 8067A – 02/2008. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET] 5 8067O–AVR–06/2013Atmel Corporation 1600 Technology Drive San Jose, CA 95110 USA Tel: (+1) (408) 441-0311 Fax: (+1) (408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Roa Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan G.K. 16F Shin-Osaki Kangyo Bldg 1-6-4 Osaki, Shinagawa-ku Tokyo 141-0032 JAPAN Tel: (+81) (3) 6417-0300 Fax: (+81) (3) 6417-0370 © 2013 Atmel Corporation. All rights reserved. / Rev.: 8067O–AVR–06/2013 Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. Atmel®, Atmel logo and combinations thereof, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 USER GUIDE Atmel SAM4S Xplained Pro Preface The Atmel® SAM4S Xplained Pro evaluation kit is a hardware platform to evaluate the ATSAM4SD32C microcontroller. Supported by the Atmel Studio integrated development platform, the kit provides easy access to the features of the Atmel ATSAM4SD32C and explains how to integrate the device in a custom design. The Xplained Pro MCU series evaluation kits include an on-board Embedded Debugger, and no external tools are necessary to program or debug the ATSAM4SD32C. The Xplained Pro extension series evaluation kits offers additional peripherals to extend the features of the board and ease the development of custom designs.Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 2 Table of Contents Preface .......................................................................................... 1 1. Introduction .............................................................................. 3 1.1. Features .............................................................................. 3 1.2. Kit overview ......................................................................... 3 2. Getting started ......................................................................... 5 2.1. Quick-start ........................................................................... 5 2.2. Connecting the kit ................................................................. 5 2.3. Design documentation and related links ..................................... 5 3. Xplained Pro ............................................................................ 6 3.1. Embedded Debugger ............................................................. 6 3.2. Hardware identification system ................................................. 6 3.3. Power supply ....................................................................... 7 3.3.1. Measuring SAM4S power consumption ......................... 7 3.4. Standard headers and connectors ............................................ 7 3.4.1. Xplained Pro extension header .................................... 7 3.4.2. Xplained Pro LCD connector ....................................... 8 3.4.3. Power header ......................................................... 10 4. Hardware user guide ............................................................ 11 4.1. Connectors ......................................................................... 11 4.1.1. I/O extension headers .............................................. 11 4.1.2. LCD extension connector .......................................... 12 4.1.3. Other headers ........................................................ 14 4.2. Peripherals ......................................................................... 14 4.2.1. NAND Flash ........................................................... 14 4.2.2. SD Card connector .................................................. 15 4.2.3. Crystals ................................................................. 15 4.2.4. Mechanical buttons .................................................. 16 4.2.5. LED ...................................................................... 16 4.2.6. Analog reference ..................................................... 16 4.3. Embedded Debugger implementation ...................................... 16 4.3.1. Serial Wire Debug ................................................... 16 4.3.2. Virtual COM port ..................................................... 16 4.3.3. Atmel Data Gateway Interface ................................... 17 5. Hardware revision history and known issues ........................ 18 5.1. Identifying product ID and revision .......................................... 18 5.2. Revision 5 .......................................................................... 18 5.3. Revision 4 .......................................................................... 18 6. Document revision history ..................................................... 19 7. Evaluation board/kit important notice .................................... 20Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 3 1. Introduction 1.1 Features ● Atmel ATSAM4SD32C microcontroller ● Embedded debugger (EDBG) ● USB interface ● Programming and debugging (target) through Serial Wire Debug (SWD) ● Virtual COM-port interface to target via UART ● Atmel Data Gateway Interface (DGI) to target via synchronous SPI or TWI ● Four GPIOs connected to target for code instrumentation ● Digital I/O ● Two mechanical buttons (user and reset button) ● One user LED ● Three extension headers ● LCD display header ● USB interface for host and device function (target) ● 2Gb NAND Flash for non-volatile storage ● SD card connector ● Adjustable analog reference ● Three possible power sources ● External power ● Embedded debugger USB ● Target USB ● 12MHz crystal ● 32kHz crystal 1.2 Kit overview The Atmel SAM4S Xplained Pro evaluation kit is a hardware platform to evaluate the Atmel ATSAM4SD32C. The kit offers a set of features that enables the ATSAM4SD32C user to get started using the ATSAM4SD32C peripherals right away and to get an understanding of how to integrate the device in their own design.Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 4 Figure 1.1. SAM4S Xplained Pro evaluation kit overviewAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 5 2. Getting started 2.1 Quick-start 3 Steps to start exploring the Atmel Xplained Pro Platform ● Download and install Atmel Studio1 . ● Launch Atmel Studio. ● Connect an USB cable to the DEBUG USB port. 2.2 Connecting the kit When connecting Atmel SAM4S Xplained Pro to your computer for the first time, the operating system will do a driver software installation. The driver file supports both 32-bit and 64-bit versions of Microsoft® Windows® XP and Windows 7. Once connected the green power LED will be lit and Atmel Studio will autodetect which Xplained Pro evaluation- and extension kit(s) that's connected. You'll be presented with relevant information like datasheets and kit documentation. You also have the option to launch Atmel Software Framework (ASF) example applications. The target device is programmed and debugged by the on-board Embedded Debugger and no external programmer or debugger tool is needed. Please refer to the Atmel Studio user guide2 for information regarding how to compile and program the kit. 2.3 Design documentation and related links The following list contains links to the most relevant documents and software for SAM4S Xplained Pro. 1. Xplained Pro products 3 - Atmel Xplained Pro is a series of small-sized and easy-to-use evaluation kits for 8- and 32-bit Atmel microcontrollers. It consists of a series of low cost MCU boards for evaluation and demonstration of features and capabilities of different MCU families. 2. SAM4S Xplained Pro User Guide 4 - PDF version of this User Guide. 3. SAM4S Xplained Pro Design Documentation 5 - Package containing schematics, BOM, assembly drawings, 3D plots, layer plots etc. 4. Atmel Studio 6 - Free Atmel IDE for development of C/C++ and assembler code for Atmel microcontrollers. 5. IAR Embedded Workbench® 7 for ARM®. This is a commercial C/C++ compiler that is available for ARM. There is a 30 day evaluation version as well as a code size limited kick-start version available from their website. The code size limit is 16K for devices with M0, M0+ and M1 cores and 32K for devices with other cores. 6. Atmel sample store 8 - Atmel sample store where you can order samples of devices. 1 http://www.atmel.com/atmelstudio 2 http://www.atmel.com/atmelstudio 3 http://www.atmel.com/XplainedPro 4 http://www.atmel.com/Images/Atmel-42075-SAM4S-Xplained-Pro_User-Guide.pdf 5 http://www.atmel.com/Images/Atmel-42075-SAM4S-Xplained-Pro_User-Guide.zip 6 http://www.atmel.com/atmelstudio 7 http://www.iar.com/en/Products/IAR-Embedded-Workbench/ARM/ 8 http://www.atmel.com/system/samplesstoreAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 6 3. Xplained Pro Xplained Pro is an evaluation platform that provides the full Atmel microcontroller experience. The platform consists of a series of Microcontroller (MCU) boards and extension boards that are integrated with Atmel Studio, have Atmel Software Framework (ASF) drivers and demo code, support data streaming and more. Xplained Pro MCU boards support a wide range of Xplained Pro extension boards that are connected through a set of standardized headers and connectors. Each extension board has an identification (ID) chip to uniquely identify which boards are mounted on a Xplained Pro MCU board. This information is used to present relevant user guides, application notes, datasheets and example code through Atmel Studio. Available Xplained Pro MCU and extension boards can be purchased in the Atmel Web Store 1 . 3.1 Embedded Debugger The SAM4S Xplained Pro contains the Atmel® Embedded Debugger (EDBG) for on-board debugging. The EDBG is a composite USB device of 3 interfaces; a debugger, Virtual COM Port and Data Gateway Interface (DGI). In conjunction with Atmel Studio, the EDBG debugger interface can program and debug the ATSAM4SD32C. On the SAM4S Xplained Pro, the SWD interface is connected between the EDBG and the ATSAM4SD32C. The Virtual COM Port is connected to a UART port on the ATSAM4SD32C (see section “Embedded Debugger implementation” on page 16 for pinout), and provides an easy way to communicate with the target application through a simple terminal software. It offers variable baud rate, parity and stop bit settings. Note that the settings on the target device UART must match the settings given in the terminal software. The DGI consists of several physical data interfaces for communication with the host computer. Please, see section “Embedded Debugger implementation” on page 16 for available interfaces and pinout. Communication over the interfaces are bidirectional. It can be used to send events and values from the ATSAM4SD32C, or as a generic printf-style data channel. Traffic over the interfaces can be timestamped on the EDBG for more accurate tracing of events. Note that timestamping imposes an overhead that reduces maximal throughput. The DGI uses a proprietary protocol, and is thus only compatible with Atmel Studio. The EDBG controls two LEDs on SAM4S Xplained Pro, a power LED and a status LED. Table 3.1, “EDBG LED control” shows how the LEDs are controlled in different operation modes. Table 3.1. EDBG LED control Operation mode Power LED Status LED Normal operation Power LED is lit when power is applied to the board. Activity indicator, LED flashes every time something happens on the EDBG. Bootloader mode (idle) The power LED and the status LED blinks simultaneously. Bootloader mode (firmware upgrade) The power LED and the status LED blinks in an alternating pattern. For further documentation on the EDBG, see the EDBG User Guide. 3.2 Hardware identification system All Xplained Pro compatible extension boards have an Atmel ATSHA204 crypto authentication chip mounted. This chip contains information that identifies the extension with its name and some extra data. When an Xplained Pro extension board is connected to an Xplained Pro MCU board the information is read and sent to Atmel Studio. The Atmel Kits extension, installed with Atmel Studio, will give relevant information, code examples and links to relevant documents. Table 3.2, “Xplained Pro ID chip content” shows the data fields stored in the ID chip with example content. Table 3.2. Xplained Pro ID chip content Data Field Data Type Example Content Manufacturer ASCII string Atmel’\0’ Product Name ASCII string Segment LCD1 Xplained Pro’\0’ Product Revision ASCII string 02’\0’ Product Serial Number ASCII string 1774020200000010’\0’ Minimum Voltage [mV] uint16_t 3000 1 http://store.atmel.com/CBC.aspx?q=c:100113Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 7 Data Field Data Type Example Content Maximum Voltage [mV] uint16_t 3600 Maximum Current [mA] uint16_t 30 3.3 Power supply The SAM4S Xplained Pro kit can be powered either by USB or by an external power source through the 4- pin power header, marked PWR. This connector is described in “Power header” on page 10. The available power sources and specifications are listed in Table 3.3, “Power sources for SAM4S Xplained Pro”. Table 3.3. Power sources for SAM4S Xplained Pro Power input Voltage requirements Current requirements Connector marking External power 5 V +/- 2 % (+/- 100 mV) for USB host operation. 4.3 V to 5.5 V if USB host operation is not required Recommended minimum is 1A to be able to provide enough current for connected USB devices and the board itself. Recommended maximum is 2A due to the input protection maximum current specification. PWR Embedded debugger USB 4.4V to 5.25V (according to USB spec) 500 mA (according to USB spec) DEBUG USB Target USB 4.4V to 5.25V (according to USB spec) 500 mA (according to USB spec) TARGET USB The kit will automatically detect which power sources are available and choose which one to use according to the following priority: 1. External power 2. Embedded debugger USB 3. Target USB Note External power is required when the 500mA through the USB connector is not enough to power a connected USB device in a USB host application. 3.3.1 Measuring SAM4S power consumption As part of an evaluation of the SAM4S it can be of interest to measure its power consumption. Because the device has a separate power plane (VCC_MCU_P3V3) on this board it is possible to measure the current consumption by measuring the current that is flowing into this plane. The VCC_MCU_P3V3 plane is connected via a jumper to the main power plane (VCC_TARGET_P3V3) and by replacing the jumper with an ampere meter it is possible to determine the current consumption. To locate the current measurement header, please refer to Figure 1.1, “SAM4S Xplained Pro evaluation kit overview”. Warning Do not power the board without having the jumper or an ampere meter mounted. This can cause the SAM4S to be powered through its I/O pins and cause undefined operation of the device. 3.4 Standard headers and connectors 3.4.1 Xplained Pro extension header All Xplained Pro kits have one or more dual row, 20 pin, 100mil extension headers. Xplained Pro MCU boards have male headers while Xplained Pro extensions have their female counterparts. Note that all pins are not always connected. However, all the connected pins follow the defined pin-out described in Table 3.4, “Xplained Pro extension header”. The extension headers can be used to connect a wide variety of Xplained ProAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 8 extensions to Xplained Pro MCU boards and to access the pins of the target MCU on Xplained Pro MCU board directly. Table 3.4. Xplained Pro extension header Pin number Name Description 1 ID Communication line to the ID chip on extension board. 2 GND Ground 3 ADC(+) Analog to digital converter , alternatively positive part of differential ADC 4 ADC(-) Analog to digital converter , alternatively negative part of differential ADC 5 GPIO1 General purpose IO 6 GPIO2 General purpose IO 7 PWM(+) Pulse width modulation , alternatively positive part of differential PWM 8 PWM(-) Pulse width modulation , alternatively positive part of differential PWM 9 IRQ/GPIO Interrupt request line and/or general purpose IO. 10 SPI_SS_B/GPIO Slave select for SPI and/or general purpose IO. 11 TWI_SDA Data line for two wire interface. Always implemented, bus type. 12 TWI_SCL Clock line for two wire interface. Always implemented, bus type. 13 USART_RX Receiver line of Universal Synchronous and Asynchronous serial Receiver and Transmitter 14 USART_TX Transmitter line of Universal Synchronous and Asynchronous serial Receiver and Transmitter 15 SPI_SS_A Slave select for SPI. Should be unique if possible. 16 SPI_MOSI Master out slave in line of Serial peripheral interface. Always implemented, bus type 17 SPI_MISO Master in slave out line of Serial peripheral interface. Always implemented, bus type 18 SPI_SCK Clock for Serial peripheral interface. Always implemented, bus type 19 GND Ground 20 VCC Power for extension board 3.4.2 Xplained Pro LCD connector The LCD connector provides the ability to connect to display extensions that have a parallel interface. The connector implements signals for a MCU parallel bus interface and a LCD controller interface as well as signals for a touchcontroller. The connector pin-out definition is shown in Table 3.5, “Xplained Pro LCD connector”. Note that usually only one display interface is implemented, either LCD controller or the MCU bus interface. A FPC/FFC connector with 50 pins and 0.5mm pitch is used for the LCD connector. The connector (XF2M-5015-1A) from Omron is used on several designs and can be used as a reference. Table 3.5. Xplained Pro LCD connector Pin number Name RGB interface description MCU interface description 1 ID Communication line to ID chip on extension board. 2 GND Ground 3 D0 Data line 4 D1 Data line 5 D2 Data line 6 D3 Data lineAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 9 Pin number Name RGB interface description MCU interface description 7 GND Ground 8 D4 Data line 9 D5 Data line 10 D6 Data line 11 D7 Data line 12 GND Ground 13 D8 Data line 14 D9 Data line 15 D10 Data line 16 D11 Data line 17 GND Ground 18 D12 Data line 19 D12 Data line 20 D14 Data line 21 D15 Data line 22 GND Ground 23 D16 Data line 24 D17 Data line 25 D18 Data line 26 D19 Data line 27 GND Ground 28 D20 Data line 29 D21 Data line 30 D22 Data line 31 D23 Data line 32 GND Ground 33 PCLK / CMD_DATA_SEL Pixel clock Command and data select. One address line of the MCU for displays where it is possible to select either the register or the data interface. 34 VSYNC / CS Vertical synchronization Chip select 35 HSYNC / WE Horizontal synchronization Write enable signal 36 DATA ENABLE / RE Data enable signal Read enable signal 37 SPI SCK Clock for Serial peripheral interface 38 SPI MOSI Master out slave in line of Serial peripheral interface 39 SPI MISO Master in slave out line of Serial peripheral interface 40 SPI SS Slave select for SPI. Should be unique if possible 41 ENABLE Display enable signal 42 TWI SDA I2C data line (maxTouch) 43 TWI SCL I2C clock line (maxTouch) 44 IRQ1 maxTouch interrupt lineAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 10 Pin number Name RGB interface description MCU interface description 45 IRQ2 Interrupt line for other I2C devices 46 PWM Backlight control 47 RESET Reset for both display and maxTouch 48 VCC 3.3V power supply for extension board 49 VCC 3.3V power supply for extension board 50 GND Ground 3.4.3 Power header The power header can be used to connect external power to the SAM4S Xplained Pro kit. The kit will automatically detect and switch to the external power if supplied. The power header can also be used as supply for external peripherals or extension boards. Care must be taken not to exceed the total current limitation of the on-board regulator for the 3.3V regulated output. To locate the current measurement header, please refer to Figure 1.1, “SAM4S Xplained Pro evaluation kit overview” Table 3.6. Power header PWR Pin number PWR header Pin name Description 1 VEXT_P5V0 External 5V input 2 GND Ground 3 VCC_P5V0 Unregulated 5V (output, derived from one of the input sources) 4 VCC_P3V3 Regulated 3.3V (output, used as main power for the kit) Note If the board is powered from a battery source it is recommended to use the PWR header. If there is a power source connected to EDBG USB, the EDBG is activated and it will consume more power.Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 11 4. Hardware user guide 4.1 Connectors This chapter describes the implementation of the relevant connectors and headers on SAM4S Xplained Pro and their connection to the ATSAM4SD32C. The tables of connections in this chapter also describes which signals are shared between the headers and on-board functionality. 4.1.1 I/O extension headers The SAM4S Xplained Pro headers EXT1, EXT2 and EXT3 offers access to the I/O of the microcontroller in order to expand the board e.g. by connecting extensions to the board. These headers all comply with the standard extension header specified in Xplained Pro Standard Extension Header. All headers have a pitch of 2.54 mm. Table 4.1. Extension header EXT1 Pin on EXT1 SAM4S pin Function Shared functionality 1 - - Communication line to ID chip on extension board. 2 - - GND 3 PA17 AD[0] 4 PA18 AD[1] 5 PA24 GPIO PIOD Interface Header 6 PA25 GPIO PIOD Interface Header 7 PA23 PWMH0 PIOD Interface Header 8 PA19 PWML0 9 PA1 WKUP1/GPIO 10 PA6 GPIO DGI_GPIO0 on EDBG 11 PA3 TWD0 EXT2 and EDBG 12 PA4 TWCK0 EXT2 and EDBG 13 PA21 USART1/RXD1 EXT2 14 PA22 USART1/TXD1 EXT2 15 PA11 SPI/NPCS[0] 16 PA13 SPI/MOSI EXT2, EXT3, LCD connector (EXT4) and EDBG 17 PA12 SPI/MISO EXT2, EXT3, LCD connector (EXT4) and EDBG 18 PA14 SPI/SPCK EXT2, EXT3, LCD connector (EXT4) and EDBG 19 - - GND 20 - - VCC Table 4.2. Extension header EXT2 Pin on EXT2 SAM4S pin Function Shared functionality 1 - - Communication line to ID chip on extension board. 2 - - GND 3 PB0 AD[4] 4 PB1 AD[5] 5 PC24 GPIO DGI_GPIO2 on EDBG 6 PC25 GPIO DGI_GPIO3 on EDBG 7 PC19 PWMH1Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 12 Pin on EXT2 SAM4S pin Function Shared functionality 8 PA20 PWML1 9 PC26 GPIO 10 PC27 GPIO 11 PA3 TWD0 EXT1 and EDBG 12 PA4 TWCK0 EXT1 and EDBG 13 PA21 USART1/RXD1 EXT1 14 PA22 USART1/TXD1 EXT1 15 PA9 SPI/NPCS[1] LCD connector (EXT4) 16 PA13 SPI/MOSI EXT1, EXT3, LCD connector (EXT4) and EDBG 17 PA12 SPI/MISO EXT1, EXT3, LCD connector (EXT4) and EDBG 18 PA14 SPI/SPCK EXT1, EXT3, LCD connector (EXT4) and EDBG 19 - - GND 20 - - VCC Table 4.3. Extension header EXT3 Pin on EXT3 SAM4S pin Function Shared functionality 1 - - Communication line to ID chip on extension board. 2 - - GND 3 PC29 AD[13] 4 PC30 AD[14] 5 PC21 GPIO 6 PC22 GPIO DGI_GPIO1 on EDBG 7 PC20 PWMH2 8 PA16 PWML2 PIOD Header 9 PA0 WKUP0/GPIO LCD connector (EXT4) 10 PC31 GPIO 11 PB4 TWD1 LCD connector (EXT4) 12 PB5 TWCK1 LCD connector (EXT4) 13 PB2 USART1/RXD1 CDC UART 14 PB3 USART1/TXD1 CDC UART 15 PA10 SPI/NPCS[2] LCD connector (EXT4) 16 PA13 SPI/MOSI EXT1, EXT2, LCD connector (EXT4) and EDBG 17 PA12 SPI/MISO EXT1, EXT2, LCD connector (EXT4) and EDBG 18 PA14 SPI/SPCK EXT1, EXT2, LCD connector (EXT4) and EDBG 19 - - GND 20 - - VCC 4.1.2 LCD extension connector Extension connector EXT4 is a special connector for LCD displays. The physical connector is an Omron Electronics XF2M-5015-1A FPC connector.Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 13 Table 4.4. LCD display connector EXT4 Pin on EXT4 SAM4S pin Function Shared functionality 1 - - Communication line to ID chip on extension board. 2 - - GND 3 PC0 D0 NAND Flash 4 PC1 D1 NAND Flash 5 PC2 D2 NAND Flash 6 PC3 D3 NAND Flash 7 - - GND 8 PC4 D4 NAND Flash 9 PC5 D5 NAND Flash 10 PC6 D6 NAND Flash 11 PC7 D7 NAND Flash 12 - - GND 13 - - 14 - - 15 - - 16 - - 17 - - GND 18 - - 19 - - 20 - - 21 - - 22 - - GND 23 - - 24 - - 25 - - 26 - - 27 - - GND 28 - - 29 - - 30 - - 31 - - 32 - - GND 33 PC18 A0 34 PC15 NPCS[1] 35 PC8 NWE 36 PC11 NRD 37 38 39 40 41 PB14 GPIO 42 PB4 TWD1/SDA EXT3Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 14 Pin on EXT4 SAM4S pin Function Shared functionality 43 PB5 TWCK1/SCL EXT3 44 PA0 WKUP0 EXT3 45 - - 46 PA15 PWML3 PIOD Interface header 47 PC28 GPIO 48 - VCC_P3V3 49 - VCC_P3V3 EXT2 50 - GND 4.1.3 Other headers In addition to the “I/O extension headers” on page 11, SAM4S Xplained Pro has two additional headers with spare signals that offers access to the I/O of the microcontroller which are otherwise not easily available elsewhere or might be favourable to have collected toghether. All headers have a pitch of 2.54mm. Table 4.5. SPARE SIGNALS header Pin on header SAM4S pin Function Shared functionality 1 PA2 DATRG User button, SW0 2 PA9 PWMF10 EXT2 3 PA26 TI0A2 SD Card and PIOD Interface header 4 PA27 TI0B2 SD Card and PIOD Interface header 5 PA28 TCLK1 SD Card and PIOD Interface header 6 PA29 TCLK2 SD Card and PIOD Interface header 7 PA31 PCK2 SD Card and PIOD Interface header 8 PB0 RTCOUT0 EXT2 9 PB1 RTCOUT1 EXT2 10 PB13 DAC0 11 PB14 DAC1 12 - - GND Table 4.6. PIOD INTERFACE header Pin on header SAM4S pin Function Shared functionality 1 PA15 PIODCEN1 LCD connector 2 PA16 PIODCEN2 EXT3 3 PA23 PIODCCLK EXT1 4 PA24 PIODC0 EXT1 5 PA25 PIODC1 EXT1 6 PA26 PIODC2 SD Card and SPARE Signals header 7 PA27 PIODC3 SD Card and SPARE Signals header 8 PA28 PIODC4 SD Card and SPARE Signals header 9 PA29 PIODC5 SD Card and SPARE Signals header 10 PA30 PIODC6 SD Card 11 PA31 PIODC7 SD Card and SPARE Signals header 12 - - GND 4.2 Peripherals 4.2.1 NAND Flash The SAM4S Xplained Pro kit has one 2Gb NAND Flash connected to the external bus interface of the SAM4S.Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 15 Table 4.7. NAND Flash connections SAM4S pin Function NAND Flash function Shared functionality PC0 D0 IO0 LCD connector PC1 D1 IO1 LCD connector PC2 D2 IO2 LCD connector PC3 D3 IO3 LCD connector PC4 D4 IO4 LCD connector PC5 D5 IO5 LCD connector PC6 D6 IO6 LCD connector PC7 D7 IO7 LCD connector PC9 NANDOE RE (active low) PC10 NANDWE WE (active low) PC13 GPIO R (active high)/ B (active low) PC14 NCS[0] CE (active low) PC16 NANDALE ALE (active low) PC17 NANDCLE CLE 4.2.2 SD Card connector The SAM4S Xplained Pro kit has one SD card connector which is connected to High Speed Multimedia Card Interface (HSMCI) of the SAM4S Table 4.8. SD Card connections SAM4S pin Function SD Card function Shared functionality PA26 MCDA2 DAT2 SPARE Signal and PIOD Interface headers PA27 MCDA3 DAT3 SPARE Signal and PIOD Interface headers PA28 MCCDA CMD SPARE Signal and PIOD Interface headers PA29 MCCK CLK SPARE Signal and PIOD Interface headers PA30 MCDA0 DAT0 PIOD Interface header PA31 MCDA1 DAT1 SPARE Signal and PIOD Interface headers PC12 GPIO Card Detect 4.2.3 Crystals The SAM4S Xplained Pro kit contains two crystals that can be used as clock sources for the SAM4S device. Each crystal has a cut-strap next to it that can be used to measure the oscillator safety factor. This is done by cutting the strap and adding a resistor across the strap. More information about oscillator allowance and safety factor can be found in appnote AVR4100 1 . Table 4.9. External 32.768kHz crystals Pin on SAM4S Function PA49 XIN32 PA48 XOUT32 1 http://www.atmel.com/images/doc8333.pdfAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 16 Table 4.10. External 12MHz crystals Pin on SAM4S Function PB9 XIN0 PB8 XOUT0 4.2.4 Mechanical buttons SAM4S Xplained Pro contains two mechanical buttons. One button is the RESET button connected to the SAM4S reset line and the other is a generic user configurable button. When a button is pressed it will drive the I/O line to GND. Table 4.11. Mechanical buttons Pin on SAM4S Silkscreen text NRST RESET PC24 SW0 4.2.5 LED There is one yellow LED available on the SAM4S Xplained Pro board that can be turned on and off. The LED can be activated by driving the connected I/O line to GND. Table 4.12. LED connections Pin on SAM4S LED PC23 Yellow LED0 4.2.6 Analog reference An adjustable voltage reference is implemented on the kit to have a reference for the ADC or DAC. The reference can be adjusted with the on-board multiturn trimmer potentiometer. Next to the potentiometer, a 2-pin header is available to measure the reference voltage for the AREF pin of the SAM4S. The voltage output range for the reference is 0V - 3.36V. 4.3 Embedded Debugger implementation SAM4S Xplained Pro contains an Embedded Debugger (EDBG) that can be used to program and debug the ATSAM4SD32C using Serial Wire Debug (SWD). The Embedded Debugger also include a Virtual Com port interface over UART, an Atmel Data Gateway Interface over SPI and TWI and it monitors four of the SAM4S GPIOs. Atmel Studio can be used as a front end for the Embedded Debugger. 4.3.1 Serial Wire Debug The Serial Wire Debug (SWD) use two pins to communicate with the target. For further information on how to use the programming and debugging capabilities of the EDBG, see “Embedded Debugger” on page 6. Table 4.13. SWD connections Pin on SAM4S Function PB7 SWD clock PB6 SWD data PB5 SWD trace output PB12 Erase 4.3.2 Virtual COM port The Embedded Debugger act as a Virtual Com Port gateway by using one of the ATSAM4SD32C UARTs. For further information on how to use the Virtual COM port see “Embedded Debugger” on page 6. Table 4.14. Virtual COM port connections Pin on SAM4S Function PB3 UART TXD (SAM4S TX line)Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 17 Pin on SAM4S Function PB2 UART RXD (SAM4S RX line) 4.3.3 Atmel Data Gateway Interface The Embedded Debugger features an Atmel Data Gateway Interface (DGI) by using either a SPI or TWI port. The DGI can be used to send a variety of data from the SAM4S to the host PC. For further information on how to use the DGI interface see “Embedded Debugger” on page 6. Table 4.15. DGI interface connections when using SPI Pin on SAM4S Function PA5 Slave select (SAM4S is Master) PA12 SPI MISO (Master In, Slave Out) PA13 SPI MOSI (Master Out, Slave in) PA14 SPI SCK (Clock Out) Table 4.16. DGI interface connections when using TWI Pin on SAM4S Function PA3 SDA (Data line) PA4 SCL (Clock line) Four GPIO lines are connected to the Embedded Debugger. The EDBG can monitor these lines and time stamp pin value changes. This makes it possible to accurately time stamp events in the SAM4S application code. For further information on how to configure and use the GPIO monitoring features see “Embedded Debugger” on page 6. Table 4.17. GPIO lines connected to the EDBG Pin on SAM4S Function PA6 GPIO0 PA22 GPIO1 PA24 GPIO2 PA25 GPIO3Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 18 5. Hardware revision history and known issues 5.1 Identifying product ID and revision The revision and product identifier of Xplained Pro boards can be found in two ways, through Atmel Studio or by looking at the sticker on the bottom side of the PCB. By connecting a Xplained Pro MCU board to a computer with Atmel Studio running, an information window will pop up. The first 6 digits of the serial number, which is listed under kit details, contain the product identifier and revision. Information about connected Xplained Pro extension boards will also appear in the Atmel Kits window. The same information can be found on the sticker on the bottom side of the PCB. Most kits will print the identifier and revision in plain text as A09-nnnn\rr where nnnn is the identifier and rr is the revision. Boards with limited space have a sticker with only a QR-code which contains a serial number string. The serial number string has the following format: "nnnnrrssssssssss" n = product identifier r = revision s = serial number The kit identifier for SAM4S Xplained Pro is 1803. 5.2 Revision 5 On this revision, the SPI clock net is improved to reduce any issues that might be caused by reflections. The SPI has been removed from the LCD (EXT4 connector) to reduce load on the clock net. The remaining clock lines have been divided into four terminated nets for each SPI source (EXT1, EXT2, EXT3, and EDBG) and routed in a star like layout. A series terminator resistor of 43ohm is placed on each clock net, close to the SPI clock pin. This reduces any issues that might be caused by reflections comming back from unterminated/ unused clock lines. It also reduces the rise/fall time of the clock edges and that will also help to reduce any reflection issues. 5.3 Revision 4 Known issues ● SAM4S has an on-die series termination of the SPI CLK which makes this signal not usable for a multi drop clock distribution because all devices along the line will see a fraction of VCC until the signal is reflected from the end of the transmission line. On the SAM4S Xplained Pro revision 4 this signal is routed to each extension connector with EXT1 at the end of the line. That means extensions that are connected along the transission line e.g. EXT3 header is likely to fail due to a non-monotinic edge caused by relections and the fraction of VCC that is present for a short time until the reflection comes back from the end of the line. Workaround: ● By slowing down the clock rise time with a capacitor, and thus effectively increasing the line length at which point it becomes a transmission line, it is possible to remove the clock issue. A 56pF capacitor has been mounted on the bottom side of the board between the SPI clock and GND. This however reduces the maximum SPI clock speed and it is recommended to not run this faster than 30MHz (this also depends on how much additional capacitance is added by connected extensions and needs to be checked case by case). The capacitor was added on revision 4 on the bottom side of the EXT3 header.Atmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 19 6. Document revision history Doc. Rev. Date Comment B 15/03/2013 Added information about changes done on rev 5 A 11/02/2013 First releaseAtmel SAM4S Xplained Pro [USER GUIDE] Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 20 7. Evaluation board/kit important notice This evaluation board/kit is intended for use for FURTHER ENGINEERING, DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY. It is not a finished product and may not (yet) comply with some or any technical or legal requirements that are applicable to finished products, including, without limitation, directives regarding electromagnetic compatibility, recycling (WEEE), FCC, CE or UL (except as may be otherwise noted on the board/kit). Atmel supplied this board/kit "AS IS," without any warranties, with all faults, at the buyer's and further users' sole risk. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies Atmel from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user's responsibility to take any and all appropriate precautions with regard to electrostatic discharge and any other technical or legal concerns. EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER USER NOR ATMEL SHALL BE LIABLE TO EACH OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. No license is granted under any patent right or other intellectual property right of Atmel covering or relating to any machine, process, or combination in which such Atmel products or services might be or are used. Mailing Address: Atmel Corporation 1600 Technology Drive San Jose, CA 95110 USAAtmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com © 2013 Atmel Corporation. All rights reserved. / Rev.: Atmel-42075B-MCU-Atmel SAM4S Xplained Pro-USER GUIDE-03/2013 Atmel®, Atmel logo and combinations thereof, AVR®, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Windows® is a registered trademark of Microsoft Corporation in U.S. and or other countries. ARM® is a registered trademark of ARM Ltd. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. APPLICATION NOTE Atmel AVR600: STK600 Expansion, Routing and Socket Boards Atmel Microcontrollers Introduction This application note describes the process of developing new routing, socket and expansion cards for the Atmel STK® 600. It also describes the physical parameters for creating such cards. The STK600 starter kit from Atmel has a sandwich design to match a specific part package and pin out to the generic pin headers. It also features an expansion area where most part pins are available. While the variety of IC packages is relatively limited, the number of possible pinouts increases rapidly with the number of pins. I.e. a 6-pin IC can have 720 (6!) different pinouts! The routing / socket card design provides a lowcost solution to support upcoming devices as the socket is the cost driving factor. STK600 users might also want to create their own routing cards to include specialized hardware to prototype their own design. Figure 1. STK600 router and socket card. 8170C−AVR−03/2013Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 2 Table of Contents 1. Routing Cards ...................................................................................... 3 1.1 Connector footprints .......................................................................................... 3 1.2 Physical dimensions and component placement .............................................. 4 1.3 Atmel STK600 socket connectors pinout .......................................................... 5 1.3.1 Signal descriptions .............................................................................. 8 2. Socket Cards ..................................................................................... 10 2.1 Power design issues ....................................................................................... 10 2.2 Connector MPN ............................................................................................... 10 2.3 Physical dimensions and component placement ............................................ 10 3. Expansion Cards ................................................................................ 11 3.1 Connector MPN ............................................................................................... 11 3.2 Physical dimensions and component placement ............................................ 12 3.3 Atmel STK600 expansion connectors pinout .................................................. 13 4. ID System .......................................................................................... 17 4.1 Signal usage ................................................................................................... 17 4.2 ID functions ..................................................................................................... 18 4.3 Examples ........................................................................................................ 19 5. Design Example ................................................................................. 20 6. Revision History ................................................................................. 22Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 3 1. Routing Cards The routing cards sit between the generic socket card and the Atmel STK600. It has one pair of electric pads underneath to mate with the STK600 spring loaded connector, and one pair of pads on top where the socket card connector connects. A part specific card with the target IC soldered on can be viewed as a routing card without the top pads. 1.1 Connector footprints A routing card should have pads to mate with the following spring loaded connectors: Table 1-1. Router card connectors. Manufacturer and MPN Quantity Comment SAMTEC, FSI-140-03-G-D-AD 2 80-pins to socket card (top) SAMTEC, FSI-150-03-G-D-AD 2 100-pins to STK600 (bottom) Figure 1-1. PCB land pattern for mating to FSI connectors. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 4 1.2 Physical dimensions and component placement Figure 1-2. Routing card connector pad placement and dimensions. Figure 1-3. Clip hole dimensions. The board thickness should be 1.6mm to be compatible with the clips. Note: Components on the main board might conflict with through hole mounted or secondary side mounted components. Areas with such components are highlighted in Figure 1-4. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 5 Figure 1-4. Height restricted areas due to main board components. 1.3 Atmel STK600 socket connectors pinout Figure 1-5 shows the pinout for the STK600 headers. This corresponds to the routing card connectors J1 and J2. Figure 1-5. STK600 socket connectors’ pinout. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 6 Table 1-2. Atmel STK600 J201 left, routing card connector J1 pinout. Signal name Pin number Signal name VTG 2 1 GND PA1 4 3 PA0 PA3 6 5 PA2 PA5 8 7 PA4 PA7 10 9 PA6 VTG 12 11 GND PB1 14 13 PB0 PB3 16 15 PB2 PB5 18 17 PB4 PB7 20 19 PB6 VTG 22 21 GND PC1 24 23 PC0 PC3 26 25 PC2 PC5 28 27 PC4 PC7 30 29 PC6 VTG 32 31 GND PD1 34 33 PD0 PD3 36 35 PD2 PD5 38 37 PD4 PD7 40 39 PD6 VTG 42 41 GND PE1 44 43 PE0 PE3 46 45 PE2 PE5 48 47 PE4 PE7 50 49 PE6 VTG 52 51 GND PF1 54 53 PF0 PF3 56 55 PF2 PF5 58 57 PF4 PF7 60 59 PF6 VTG 62 61 GND PG1 64 63 PG0 PG3 66 65 PG2 PG5 68 67 PG4 PG7 70 69 PG6 VTG 72 71 GND PH1 74 73 PH0 PH3 76 75 PH2 PH5 78 77 PH4 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 7 PH7 80 79 PH6 VTG 82 81 GND AREF0 84 83 XTAL1 AREF1 86 85 XTAL2 TGT_MOSI 88 87 GND TGT_MISO 90 89 TOSC1 TGT_SCK 92 91 TOSC2 TDI 94 93 TGT_RESET TDO 96 95 GND TMS 98 97 Vext TCK 100 99 Vcc Table 1-3. Atmel STK600 J202 right, routing card connector J2 pinout. Signal name Pin number Signal name VTG 2 1 GND PJ1 4 3 PJ0 PJ3 6 5 PJ2 PJ5 8 7 PJ4 PJ7 10 9 PJ6 VTG 12 11 GND PK1 14 13 PK0 PK3 16 15 PK2 PK5 18 17 PK4 PK7 20 19 PK6 VTG 22 21 GND PL1 24 23 PL0 PL3 26 25 PL2 PL5 28 27 PL4 PL7 30 29 PL6 VTG 32 31 GND PM1 34 33 PM0 PM3 36 35 PM2 PM5 38 37 PM4 PM7 40 39 PM6 VTG 42 41 GND PN1 44 43 PN0 PN3 46 45 PN2 PN5 48 47 PN4 PN7 50 49 PN6 VTG 52 51 GND PP1 54 53 PP0 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 8 PP3 56 55 PP2 PP5 58 57 PP4 PP7 60 59 PP6 VTG 62 61 GND PQ1 64 63 PQ0 PQ3 66 65 PQ2 PQ5 68 67 PQ4 PQ7 70 69 PQ6 VBUST 72 71 DP UVCON 74 73 DN Vcc 76 75 UID Vext 78 77 GND TGT_PDATA1 80 79 TGT_PDATA0 TGT_PDATA3 82 81 TGT_PDATA2 TGT_PDATA5 84 83 TGT_PDATA4 TGT_PDATA7 86 85 TGT_PDATA6 TGT_PCTRL1 88 87 TGT_PCTRL0 TGT_PCTRL3 90 89 TGT_PCTRL2 TGT_PCTRL5 92 91 TGT_PCTRL4 TGT_PCTRL7 94 93 TGT_PCTRL6 BOARD_ID1 96 95 BOARD_ID0 BOARD_ID3 98 97 BOARD_ID2 BOARD_ID5 100 99 BOARD_ID4 1.3.1 Signal descriptions Table 1-4. Socket card connector pin description. Atmel STK600 signal name MCU Comment PAx, PBx etc PAx, PBx etc 1-to-1 MCU pin mapping VTG Vcc Target supply rail controlled by Atmel AVR Studio® / STK600 GND GND AREFx AREF Analog reference voltage, controlled by AVR Studio / STK600 XTALx XTALx Clock pins connected to oscillator on STK600 TGT_SCK, TGT_MISO, TGT_MOSI ISP pins ISP programming interface TGT_TDI, TGT_TDO, TGT_TMS, TGT_TCK JTAG pins JTAG programming interface VBUST VBUS VBUS (sense) for USB UID UID ID pin for USB OTG UVCON UVCON USB VBUS generation control for USB OTG. A low level on this signal enables VBUS generation DP, DN DP, DN USB differential pair TGT_PDATA(0-7) (HV) data pins Data pins for high voltage (PP/HVSP) programming Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 9 TGT_CTRL0 (HV) BS2 Control signals for High voltage Parallel Programming / Serial Programming. Refer to AVR datasheet for further information. On AVRs with common XA1/BS2, XA1 is used. On AVRs with common BS1/PAGEL, BS1 is used. TGT_CTRL1 (HV) Ready/Busy TGT_CTRL2 (HV) /OE TGT_CTRL3 (HV) /WR TGT_CTRL4 (HV) BS1 TGT_CTRL5 (HV) XA0 TGT_CTRL6 (HV) XA1 TGT_CTRL7 (HV) PAGEL BOARD_IDn none ID system for router / socket / expansion cards, see Chapter 4 - ID System Notes: 1. Not all AVR will have every pin (ex. two aref pins, tosc or usb). 2. A MCU pin will fan-out to both Pnx pin and to the programming interface(s) located at that pin. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 10 2. Socket Cards Socket cards route each pin from the IC socket to separate pins on the spring loaded connectors on the bottom side, facing the routing card. 2.1 Power design issues As all routing is handled by the routing card, even power lines and power decoupling is ignored at the socket card. This produces less than ideal power design, which may lead to unwanted noise, ground bounce, and other effects. It should therefore be expected that heavily loaded designs cannot run at full speed on the Atmel STK600. Likewise, such power design is not recommended for custom designs. 2.2 Connector MPN Table 2-1. Socket card connector. Manufacturer and MPN Quantity Comment SAMTEC, FSI-140-03-G-D-AD 2 Spring loaded 80-pin connector 2.3 Physical dimensions and component placement Figure 2-1. Socket card connector placement and dimensions. ST1 J1 J2 45° Note! 105mm 94mm 66mm 7mm The board thickness should be 1.6mm to be compatible with the clips. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 11 3. Expansion Cards The Atmel STK600 features an expansion area where cards for custom peripherals like memory expansion, LCD etc can be placed. STK600 routes all part pins and power to the expansion card connectors. 3.1 Connector MPN Table 3-1. Expansion card connector. Manufacturer and MPN Quantity Comment FCI, 61082-101402LF 2 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 12 3.2 Physical dimensions and component placement Figure 3-1. Expansion card connector placement and dimensions. There is no requirement to board thickness. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 13 3.3 Atmel STK600 expansion connectors pinout Figure 3-2. Pinout for expansion connectors. Table 3-2. STK600 J301 “expand0” connector pinout. Signal name Pin number Signal name VTG 2 1 GND PA1 4 3 PA0 PA3 6 5 PA2 PA5 8 7 PA4 PA7 10 9 PA6 VTG 12 11 GND PB1 14 13 PB0 PB3 16 15 PB2 PB5 18 17 PB4 PB7 20 19 PB6 VTG 22 21 GND PC1 24 23 PC0 PC3 26 25 PC2 PC5 28 27 PC4 PC7 30 29 PC6 VTG 32 31 GND PD1 34 33 PD0 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 14 PD3 36 35 PD2 PD5 38 37 PD4 PD7 40 39 PD6 VTG 42 41 GND PE1 44 43 PE0 PE3 46 45 PE2 PE5 48 47 PE4 PE7 50 49 PE6 VTG 52 51 GND PF1 54 53 PF0 PF3 56 55 PF2 PF5 58 57 PF4 PF7 60 59 PF6 VTG 62 61 GND PG1 64 63 PG0 PG3 66 65 PG2 PG5 68 67 PG4 PG7 70 69 PG6 VTG 72 71 GND PH1 74 73 PH0 PH3 76 75 PH2 PH5 78 77 PH4 PH7 80 79 PH6 VTG 82 81 GND AREF0 84 83 XTAL1 AREF1 86 85 XTAL2 TGT_MOSI 88 87 GND TGT_MISO 90 89 TOSC1 TGT_SCK 92 91 TOSC2 TDI 94 93 TGT_RESET TDO 96 95 Vcc6 TMS 98 97 GND TCK 100 99 Vcc6 Table 3-3. Atmel STK600 J302 “expand1” connector pinout. Signal name Pin number Signal name VTG 2 1 GND PJ1 4 3 PJ0 PJ3 6 5 PJ2 PJ5 8 7 PJ4 PJ7 10 9 PJ6 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 15 VTG 12 11 GND PK1 14 13 PK0 PK3 16 15 PK2 PK5 18 17 PK4 PK7 20 19 PK6 VTG 22 21 GND PL1 24 23 PL0 PL3 26 25 PL2 PL5 28 27 PL4 PL7 30 29 PL6 VTG 32 31 GND PM1 34 33 PM0 PM3 36 35 PM2 PM5 38 37 PM4 PM7 40 39 PM6 VTG 42 41 GND PN1 44 43 PN0 PN3 46 45 PN2 PN5 48 47 PN4 PN7 50 49 PN6 VTG 52 51 GND PP1 54 53 PP0 PP3 56 55 PP2 PP5 58 57 PP4 PP7 60 59 PP6 VTG 62 61 GND PQ1 64 63 PQ0 PQ3 66 65 PQ2 PQ5 68 67 PQ4 PQ7 70 69 PQ6 Vext 72 71 GND Vext 74 73 GND GND 76 75 Vcc GND 78 77 Vcc TGT_PDATA1 80 79 TGT_PDATA0 TGT_PDATA3 82 81 TGT_PDATA2 TGT_PDATA5 84 83 TGT_PDATA4 TGT_PDATA7 86 85 TGT_PDATA6 TGT_PCTRL1 88 87 TGT_PCTRL0 TGT_PCTRL3 90 89 TGT_PCTRL2 TGT_PCTRL5 92 91 TGT_PCTRL4 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 16 TGT_PCTRL7 94 93 TGT_PCTRL6 Vcc3 96 95 GND BOARD_ID1 98 97 BOARD_ID0 BOARD_ID7 100 99 BOARD_ID6 Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 17 4. ID System The Atmel STK600 features an ID system to identify which routing, socket and expansion card is attached. The STK600 can impose voltage limitations based on the IDs, and Atmel AVR Studio will notify the user if the combination is incorrect. The ID system consists of two common output and two board unique input signals. Each input is one of sixteen possible values based in the input signals – giving a total ID space of 256. Three IDs are reserved for custom use and can be implemented without use of ICs. Table 4-1. IDs reserved for custom use. Type ID Board limited to 1.8V 0xCA Board limited to 3.3V 0xCC No limit on voltage 0xCF The ID 0xff indicates no board present. 4.1 Signal usage Table 4-2. ID system signal usage. Name Direction Function BOARD_ID0 Output (A) Common output to functions BOARD_ID1 Output (B) Common output to functions BOARD_ID2 Input Input from routing card BOARD_ID3 Input Input from routing card BOARD_ID4 Input Input from socket card BOARD_ID5 Input Input from socket card BOARD_ID6 Input Input from expansion card BOARD_ID7 Input Input from expansion card Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 18 4.2 ID functions The functions and their output according to input A and B: B A 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 1 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 Functions as logic expressions: Function Expression ID 0 0 0x0 1 A + B 0x1 2 AB 0x2 3 B 0x3 4 AB 0x4 5 A 0x5 6 ⊕ BA 0x6 7 AB 0x7 8 AB 0x8 9 ⊕ BA 0x9 10 A 0xA 11 B + AB 0xB 12 B 0xC 13 B A⋅+ B 0xD 14 A + B 0xE 15 1 0xF Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 19 4.3 Examples For a socket card to report the ID 0xCA: Route BOARD_ID1 to BOARD_ID4 and BOARD_ID0 to BOARD_ID5 Figure 4-1. Socket card ID example. For an expansion card to report the ID 0xCF: Route BOARD_ID0 to BOARD_ID6 and VCC to BOARD_ID7 Figure 4-2. Expansion card ID example. For a router card to report the ID 0xCC: Route BOARD_ID1 to both BOARD_ID2 and BOARD_ID3. Figure 4-3. Routing card ID example. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 20 5. Design Example To support a new package type one would typically start with designing the socket card. The pinout between the socket card and routing card is not defined and left to the designer. An example is given in Figure 5-1. Next is the design of the routing card (Figure 5-3). The routing card’s role is to connect each pin from the socket card to the corresponding pin on the Atmel STK600. In addition to decoupling etc, the routing card should also fan-out the correct signals to programming headers. Each card in the stack has its own board_id pins; the routing card is responsible for passing on the signal to the socket card. Figure 5-1. Schema capture of socket card. Both the socket and routing card must also include the clip holes: Figure 5-2. Clip holes included in schematic. Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 21 Figure 5-3. Schema capture of routing card. Copyright © 2008, Atmel Corporation Atmel AVR600: STK600 Expansion, Routing and Socket Boards [APPLICATION NOTE] 8170C−AVR−03/2013 22 6. Revision History Doc. Rev. Date Comments 8170C 03/2013 Example schematics for the ID system are updated 8170B 12/2010 8170A 10/2008 Initial document release Atmel Corporation 1600 Technology Drive San Jose, CA 95110 USA Tel: (+1)(408) 441-0311 Fax: (+1)(408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan G.K. 16F Shin-Osaki Kangyo Building 1-6-4 Osaki, Shinagawa-ku Tokyo 141-0032 JAPAN Tel: (+81)(3) 6417-0300 Fax: (+81)(3) 6417-0370 © 2013 Atmel Corporation. All rights reserved. / Rev.: 8170C−AVR−03/2013 Atmel®, Atmel logo and combinations thereof, AVR®, AVR Studio®, Enabling Unlimited Possibilities®, STK®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. 8159E–AVR–02/2013 Features • High-performance, Low-power Atmel®AVR® 8-bit Microcontroller • Advanced RISC Architecture – 130 Powerful Instructions – Most Single-clock Cycle Execution – 32 x 8 General Purpose Working Registers – Fully Static Operation – Up to 16MIPS Throughput at 16MHz – On-chip 2-cycle Multiplier • High Endurance Non-volatile Memory segments – 8KBytes of In-System Self-programmable Flash program memory – 512Bytes EEPROM – 1KByte Internal SRAM – Write/Erase Cycles: 10,000 Flash/100,000 EEPROM – Data retention: 20 years at 85C/100 years at 25C(1) – Optional Boot Code Section with Independent Lock Bits • In-System Programming by On-chip Boot Program • True Read-While-Write Operation – Programming Lock for Software Security • Atmel QTouch® library support – Capacitive touch buttons, sliders and wheels – Atmel QTouch and QMatrix acquisition – Up to 64 sense channels • Peripheral Features – Two 8-bit Timer/Counters with Separate Prescaler, one Compare Mode – One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode – Real Time Counter with Separate Oscillator – Three PWM Channels – 8-channel ADC in TQFP and QFN/MLF package • Eight Channels 10-bit Accuracy – 6-channel ADC in PDIP package • Six Channels 10-bit Accuracy – Byte-oriented Two-wire Serial Interface – Programmable Serial USART – Master/Slave SPI Serial Interface – Programmable Watchdog Timer with Separate On-chip Oscillator – On-chip Analog Comparator • Special Microcontroller Features – Power-on Reset and Programmable Brown-out Detection – Internal Calibrated RC Oscillator – External and Internal Interrupt Sources – Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, and Standby • I/O and Packages – 23 Programmable I/O Lines – 28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF • Operating Voltages – 2.7 - 5.5V – 0 - 16MHz • Power Consumption at 4MHz, 3V, 25C – Active: 3.6mA – Idle Mode: 1.0mA – Power-down Mode: 0.5µA 8-bit Atmel Microcontroller with 8KB In-System Programmable Flash ATmega8AATmega8A [DATASHEET] 2 8159E–AVR–02/2013 1. Pin Configurations Figure 1-1. Pinout ATmega8A 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 (INT1) PD3 (XCK/T0) PD4 GND VCC GND VCC (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 PC1 (ADC1) PC0 (ADC0) ADC7 GND AREF ADC6 AVCC PB5 (SCK) 32 31 30 29 28 27 26 25 9 10 11 12 13 14 15 16 (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 (OC1A) PB1 (SS/OC1B) PB2 (MOSI/OC2) PB3 (MISO) PB4 PD2 (INT0) PD1 (TXD) PD0 (RXD) PC6 (RESET) PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) TQFP Top View 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 (RESET) PC6 (RXD) PD0 (TXD) PD1 (INT0) PD2 (INT1) PD3 (XCK/T0) PD4 VCC GND (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) PC1 (ADC1) PC0 (ADC0) GND AREF AVCC PB5 (SCK) PB4 (MISO) PB3 (MOSI/OC2) PB2 (SS/OC1B) PB1 (OC1A) PDIP 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 32 31 30 29 28 27 26 25 9 10 11 12 13 14 15 16 MLF Top View (INT1) PD3 (XCK/T0) PD4 GND VCC GND VCC (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 PC1 (ADC1) PC0 (ADC0) ADC7 GND AREF ADC6 AVCC PB5 (SCK) (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 (OC1A) PB1 (SS/OC1B) PB2 (MOSI/OC2) PB3 (MISO) PB4 PD2 (INT0) PD1 (TXD) PD0 (RXD) PC6 (RESET) PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) NOTE: The large center pad underneath the MLF packages is made of metal and internally connected to GND. It should be soldered or glued to the PCB to ensure good mechanical stability. If the center pad is left unconneted, the package might loosen from the PCB.ATmega8A [DATASHEET] 3 8159E–AVR–02/2013 2. Overview The Atmel®AVR® ATmega8A is a low-power CMOS 8-bit microcontroller based on the AVR RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega8A achieves throughputs approaching 1 MIPS per MHz, allowing the system designer to optimize power consumption versus processing speed. 2.1 Block Diagram Figure 2-1. Block Diagram INTERNAL OSCILLATOR OSCILLATOR WATCHDOG TIMER MCU CTRL. & TIMING OSCILLATOR TIMERS/ COUNTERS INTERRUPT UNIT STACK POINTER EEPROM SRAM STATUS REGISTER USART PROGRAM COUNTER PROGRAM FLASH INSTRUCTION REGISTER INSTRUCTION DECODER PROGRAMMING LOGIC SPI ADC INTERFACE COMP. INTERFACE PORTC DRIVERS/BUFFERS PORTC DIGITAL INTERFACE GENERAL PURPOSE REGISTERS X Y Z ALU + - PORTB DRIVERS/BUFFERS PORTB DIGITAL INTERFACE PORTD DIGITAL INTERFACE PORTD DRIVERS/BUFFERS XTAL1 XTAL2 CONTROL LINES VCC GND MUX & ADC AGND AREF PC0 - PC6 PB0 - PB7 PD0 - PD7 AVR CPU TWI RESETATmega8A [DATASHEET] 4 8159E–AVR–02/2013 The Atmel®AVR® AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The ATmega8A provides the following features: 8K bytes of In-System Programmable Flash with Read-WhileWrite capabilities, 512 bytes of EEPROM, 1K byte of SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with compare modes, internal and external interrupts, a serial programmable USART, a byte oriented Two-wire Serial Interface, a 6-channel ADC (eight channels in TQFP and QFN/MLF packages) with 10-bit accuracy, a programmable Watchdog Timer with Internal Oscillator, an SPI serial port, and five software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue functioning. The Power-down mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next Interrupt or Hardware Reset. In Power-save mode, the asynchronous timer continues to run, allowing the user to maintain a timer base while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules except asynchronous timer and ADC, to minimize switching noise during ADC conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low-power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The Flash Program memory can be reprogrammed In-System through an SPI serial interface, by a conventional non-volatile memory programmer, or by an On-chip boot program running on the AVR core. The boot program can use any interface to download the application program in the Application Flash memory. Software in the Boot Flash Section will continue to run while the Application Flash Section is updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the Atmel ATmega8A is a powerful microcontroller that provides a highly-flexible and cost-effective solution to many embedded control applications. The Atmel AVR ATmega8A is supported with a full suite of program and system development tools, including C compilers, macro assemblers, program simulators and evaluation kits. 2.2 Pin Descriptions 2.2.1 VCC Digital supply voltage. 2.2.2 GND Ground. 2.2.3 Port B (PB7:PB0) – XTAL1/XTAL2/TOSC1/TOSC2 Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Depending on the clock selection fuse settings, PB6 can be used as input to the inverting Oscillator amplifier and input to the internal clock operating circuit. Depending on the clock selection fuse settings, PB7 can be used as output from the inverting Oscillator amplifier. If the Internal Calibrated RC Oscillator is used as chip clock source, PB7:6 is used as TOSC2:1 input for the Asynchronous Timer/Counter2 if the AS2 bit in ASSR is set.ATmega8A [DATASHEET] 5 8159E–AVR–02/2013 The various special features of Port B are elaborated in “Alternate Functions of Port B” on page 56 and “System Clock and Clock Options” on page 24. 2.2.4 Port C (PC5:PC0) Port C is an 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port C output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running. 2.2.5 PC6/RESET If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical characteristics of PC6 differ from those of the other pins of Port C. If the RSTDISBL Fuse is unprogrammed, PC6 is used as a Reset input. A low level on this pin for longer than the minimum pulse length will generate a Reset, even if the clock is not running. The minimum pulse length is given in Table 26-3 on page 228. Shorter pulses are not guaranteed to generate a Reset. The various special features of Port C are elaborated on page 59. 2.2.6 Port D (PD7:PD0) Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port D also serves the functions of various special features of the ATmega8A as listed on page 61. 2.2.7 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running. The minimum pulse length is given in Table 26-3 on page 228. Shorter pulses are not guaranteed to generate a reset. 2.2.8 AVCC AVCC is the supply voltage pin for the A/D Converter, Port C (3:0), and ADC (7:6). It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. Note that Port C (5:4) use digital supply voltage, VCC. 2.2.9 AREF AREF is the analog reference pin for the A/D Converter. 2.2.10 ADC7:6 (TQFP and QFN/MLF Package Only) In the TQFP and QFN/MLF package, ADC7:6 serve as analog inputs to the A/D converter. These pins are powered from the analog supply and serve as 10-bit ADC channels.ATmega8A [DATASHEET] 6 8159E–AVR–02/2013 3. Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. Note: 1. 4. Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C. 5. About Code Examples This datasheet contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. 6. Capacitive touch sensing The Atmel® QTouch® Library provides a simple to use solution to realize touch sensitive interfaces on most Atmel AVR® microcontrollers. The QTouch Library includes support for the QTouch and QMatrix® acquisition methods. Touch sensing can be added to any application by linking the appropriate Atmel QTouch Library for the AVR Microcontroller. This is done by using a simple set of APIs to define the touch channels and sensors, and then calling the touch sensing API’s to retrieve the channel information and determine the touch sensor states. The QTouch Library is FREE and downloadable from the Atmel website at the following location: www.atmel.com/qtouchlibrary. For implementation details and other information, refer to the Atmel QTouch Library User Guide - also available for download from the Atmel website.ATmega8A [DATASHEET] 7 8159E–AVR–02/2013 7. AVR CPU Core 7.1 Overview This section discusses the Atmel®AVR® core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. Figure 7-1. Block Diagram of the AVR MCU Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the Program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the Program memory. This concept enables instructions to be executed in every clock cycle. The Program memory is In-System Reprogrammable Flash memory. The fast-access Register File contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash Program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. Flash Program Memory Instruction Register Instruction Decoder Program Counter Control Lines 32 x 8 General Purpose Registrers ALU Status and Control I/O Lines EEPROM Data Bus 8-bit Data SRAM Direct Addressing Indirect Addressing Interrupt Unit SPI Unit Watchdog Timer Analog Comparator i/O Module 2 i/O Module1 i/O Module nATmega8A [DATASHEET] 8 8159E–AVR–02/2013 The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. The Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every Program memory address contains a 16- or 32-bit instruction. Program Flash memory space is divided in two sections, the Boot program section and the Application program section. Both sections have dedicated Lock Bits for write and read/write protection. The SPM instruction that writes into the Application Flash memory section must reside in the Boot program section. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the reset routine (before subroutines or interrupts are executed). The Stack Pointer SP is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional global interrupt enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O Memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. 7.2 Arithmetic Logic Unit – ALU The high-performance Atmel®AVR® ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See the “Instruction Set” section for a detailed description. 7.3 Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software. 7.3.1 SREG – The AVR Status Register Bit 7 6 5 4 3 2 1 0 I T H S V N Z C SREG Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 9 8159E–AVR–02/2013 • Bit 7 – I: Global Interrupt Enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the Instruction Set Reference. • Bit 6 – T: Bit Copy Storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half Carry Flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry is useful in BCD arithmetic. See the “Instruction Set Description” for detailed information. • Bit 4 – S: Sign Bit, S = N V The S-bit is always an exclusive or between the Negative Flag N and the Two’s Complement Overflow Flag V. See the “Instruction Set Description” for detailed information. • Bit 3 – V: Two’s Complement Overflow Flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See the “Instruction Set Description” for detailed information. • Bit 2 – N: Negative Flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 1 – Z: Zero Flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 0 – C: Carry Flag The Carry Flag C indicates a Carry in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. 7.4 General Purpose Register File The Register File is optimized for the Atmel®AVR® Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input. • Two 8-bit output operands and one 8-bit result input. • Two 8-bit output operands and one 16-bit result input. • One 16-bit output operand and one 16-bit result input. Figure 7-2 shows the structure of the 32 general purpose working registers in the CPU.ATmega8A [DATASHEET] 10 8159E–AVR–02/2013 Figure 7-2. AVR CPU General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 7-2, each register is also assigned a Data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y-, and Z-pointer Registers can be set to index any register in the file. 7.4.1 The X-register, Y-register and Z-register The registers R26:R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the Data Space. The three indirect address registers X, Y and Z are defined as described in Figure 7-3. Figure 7-3. The X-, Y- and Z-Registers In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the Instruction Set Reference for details). 7.5 Stack Pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. Note that the Stack is implemented as growing from higher to lower memory 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E Purpose R15 0x0F Working R16 0x10 Registers R17 0x11 … R26 0x1A X-register Low Byte R27 0x1B X-register High Byte R28 0x1C Y-register Low Byte R29 0x1D Y-register High Byte R30 0x1E Z-register Low Byte R31 0x1F Z-register High Byte 15 XH XL 0 X-register 7 0 7 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 0 7 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 7 0 7 0 R31 (0x1F) R30 (0x1E)ATmega8A [DATASHEET] 11 8159E–AVR–02/2013 locations. The Stack Pointer Register always points to the top of the Stack. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. A Stack PUSH command will decrease the Stack Pointer. The Stack in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. Initial Stack Pointer value equals the last address of the internal SRAM and the Stack Pointer must be set to point above start of the SRAM, see Figure 8-2 on page 16. See Table 7-1 for Stack Pointer details. The Atmel®AVR® Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. 7.5.1 SPH and SPL – Stack Pointer High and Low Register 7.6 Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The Atmel®AVR®CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 7-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. Table 7-1. Stack Pointer instructions Instruction Stack pointer Description PUSH Decremented by 1 Data is pushed onto the stack CALL ICALL RCALL Decremented by 2 Return address is pushed onto the stack with a subroutine call or interrupt POP Incremented by 1 Data is popped from the stack RET RETI Incremented by 2 Return address is popped from the stack with return from subroutine or return from interrupt Bit 15 14 13 12 11 10 9 8 SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 SPH SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL 76543210 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 00000000ATmega8A [DATASHEET] 12 8159E–AVR–02/2013 Figure 7-4. The Parallel Instruction Fetches and Instruction Executions Figure 7-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 7-5. Single Cycle ALU Operation 7.7 Reset and Interrupt Handling The Atmel®AVR® provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate Program Vector in the Program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. Depending on the Program Counter value, interrupts may be automatically disabled when Boot Lock Bits BLB02 or BLB12 are programmed. This feature improves software security. See the section “Memory Programming” on page 207 for details. The lowest addresses in the Program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of Vectors is shown in “Interrupts” on page 44. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. The Interrupt Vectors can be moved to the start of the boot Flash section by setting the Interrupt Vector Select (IVSEL) bit in the General Interrupt Control Register (GICR). Refer to “Interrupts” on page 44 for more information. The Reset Vector can also be moved to the start of the boot Flash section by programming the BOOTRST Fuse, see “Boot Loader Support – Read-While-Write Self-Programming” on page 194. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPU Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPUATmega8A [DATASHEET] 13 8159E–AVR–02/2013 handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the global interrupt enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the global interrupt enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence. When using the SEI instruction to enable interrupts, the instruction following SEI will be executed before any pending interrupts, as shown in the following example. Assembly Code Example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMWE ; start EEPROM write sbi EECR, EEWE out SREG, r16 ; restore SREG value (I-bit) C Code Example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ _CLI(); EECR |= (1< xxx :. :. :. Table 12-2. Reset and Interrupt Vectors Placement BOOTRST(1) IVSEL Reset Address Interrupt Vectors Start Address 1 0 0x000 0x001 1 1 0x000 Boot Reset Address + 0x001 0 0 Boot Reset Address 0x001 0 1 Boot Reset Address Boot Reset Address + 0x001ATmega8A [DATASHEET] 46 8159E–AVR–02/2013 When the BOOTRST Fuse is unprogrammed, the boot section size set to 2K bytes and the IVSEL bit in the GICR Register is set before any interrupts are enabled, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: AddressLabels Code Comments $000 rjmp RESET ; Reset handler ; $001 RESET:ldi r16,high(RAMEND); Main program start $002 out SPH,r16 ; Set Stack Pointer to top of RAM $003 ldi r16,low(RAMEND) $004 out SPL,r16 $005 sei ; Enable interrupts $006 xxx ; .org $c01 $c01 rjmp EXT_INT0 ; IRQ0 Handler $c02 rjmp EXT_INT1 ; IRQ1 Handler :. :. :. ; $c12 rjmp SPM_RDY ; Store Program Memory Ready Handler When the BOOTRST Fuse is programmed and the boot section size set to 2K bytes, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: AddressLabels Code Comments .org $001 $001 rjmp EXT_INT0 ; IRQ0 Handler $002 rjmp EXT_INT1 ; IRQ1 Handler :. :. :. ; $012 rjmp SPM_RDY ; Store Program Memory Ready Handler ; .org $c00 $c00 rjmp RESET ; Reset handler ; $c01 RESET:ldi r16,high(RAMEND); Main program start $c02 out SPH,r16 ; Set Stack Pointer to top of RAM $c03 ldi r16,low(RAMEND) $c04 out SPL,r16 $c05 sei ; Enable interrupts $c06 xxxATmega8A [DATASHEET] 47 8159E–AVR–02/2013 When the BOOTRST Fuse is programmed, the boot section size set to 2K bytes, and the IVSEL bit in the GICR Register is set before any interrupts are enabled, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: AddressLabels Code Comments ; .org $c00 $c00 rjmp RESET ; Reset handler $c01 rjmp EXT_INT0 ; IRQ0 Handler $c02 rjmp EXT_INT1 ; IRQ1 Handler :. :. :. ; $c12 rjmp SPM_RDY ; Store Program Memory Ready Handler $c13 RESET: ldi r16,high(RAMEND); Main program start $c14 out SPH,r16 ; Set Stack Pointer to top of RAM $c15 ldi r16,low(RAMEND) $c16 out SPL,r16 $c17 sei ; Enable interrupts $c18 xxx 12.1.1 Moving Interrupts Between Application and Boot Space The General Interrupt Control Register controls the placement of the Interrupt Vector table. 12.2 Register Description 12.2.1 GICR – General Interrupt Control Register • Bit 1 – IVSEL: Interrupt Vector Select When the IVSEL bit is cleared (zero), the Interrupt Vectors are placed at the start of the Flash memory. When this bit is set (one), the Interrupt Vectors are moved to the beginning of the Boot Loader section of the Flash. The actual address of the start of the boot Flash section is determined by the BOOTSZ Fuses. Refer to the section “Boot Loader Support – Read-While-Write Self-Programming” on page 194 for details. To avoid unintentional changes of Interrupt Vector tables, a special write procedure must be followed to change the IVSEL bit: 1. Write the Interrupt Vector Change Enable (IVCE) bit to one. 2. Within four cycles, write the desired value to IVSEL while writing a zero to IVCE. Interrupts will automatically be disabled while this sequence is executed. Interrupts are disabled in the cycle IVCE is set, and they remain disabled until after the instruction following the write to IVSEL. If IVSEL is not written, interrupts remain disabled for four cycles. The I-bit in the Status Register is unaffected by the automatic disabling. Note: If Interrupt Vectors are placed in the Boot Loader section and Boot Lock bit BLB02 is programmed, interrupts are disabled while executing from the Application section. If Interrupt Vectors are placed in the Application section and Boot Lock bit BLB12 is programed, interrupts are disabled while executing from the Boot Loader section. Refer to the section “Boot Loader Support – Read-While-Write Self-Programming” on page 194 for details on Boot Lock Bits. Bit 7 6 5 4 3 2 1 0 INT1 INT0 – – – – IVSEL IVCE GICR Read/Write R/W R/W R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 48 8159E–AVR–02/2013 • Bit 0 – IVCE: Interrupt Vector Change Enable The IVCE bit must be written to logic one to enable change of the IVSEL bit. IVCE is cleared by hardware four cycles after it is written or when IVSEL is written. Setting the IVCE bit will disable interrupts, as explained in the IVSEL description above. See Code Example below. Assembly Code Example Move_interrupts: ; Enable change of Interrupt Vectors ldi r16, (1< CSn2:0 > 1). The number of system clock cycles from when the timer is enabled to the first count occurs can be from 1 to N+1 system clock cycles, where N equals the prescaler divisor (8, 64, 256, or 1024). It is possible to use the prescaler reset for synchronizing the Timer/Counter to program execution. However, care must be taken if the other Timer/Counter that shares the same prescaler also uses prescaling. A prescaler reset will affect the prescaler period for all Timer/Counters it is connected to. 16.4 External Clock Source An external clock source applied to the T1/T0 pin can be used as Timer/Counter clock (clkT1/clkT0). The T1/T0 pin is sampled once every system clock cycle by the pin synchronization logic. The synchronized (sampled) signal is then passed through the edge detector. Figure 16-1 shows a functional equivalent block diagram of the T1/T0 synchronization and edge detector logic. The registers are clocked at the positive edge of the internal system clock (clkI/O). The latch is transparent in the high period of the internal system clock. The edge detector generates one clkT1/clkT0 pulse for each positive (CSn2:0 = 7) or negative (CSn2:0 = 6) edge it detects. Figure 16-1. T1/T0 Pin Sampling The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles from an edge has been applied to the T1/T0 pin to the counter is updated. Tn_sync (To Clock Select Logic) Synchronization Edge Detector D Q D Q LE Tn D Q clkI/OATmega8A [DATASHEET] 72 8159E–AVR–02/2013 Enabling and disabling of the clock input must be done when T1/T0 has been stable for at least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated. Each half period of the external clock applied must be longer than one system clock cycle to ensure correct sampling. The external clock must be guaranteed to have less than half the system clock frequency (fExtClk < fclk_I/O/2) given a 50/50% duty cycle. Since the edge detector uses sampling, the maximum frequency of an external clock it can detect is half the sampling frequency (Nyquist sampling theorem). However, due to variation of the system clock frequency and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is recommended that maximum frequency of an external clock source is less than fclk_I/O/2.5. An external clock source can not be prescaled. Figure 16-2. Prescaler for Timer/Counter0 and Timer/Counter1(1) Note: 1. The synchronization logic on the input pins (T1/T0) is shown in Figure 16-1. 16.5 Register Description 16.5.1 SFIOR – Special Function IO Register • Bit 0 – PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0 When this bit is written to one, the Timer/Counter1 and Timer/Counter0 prescaler will be reset. The bit will be cleared by hardware after the operation is performed. Writing a zero to this bit will have no effect. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler and a reset of this prescaler will affect both timers. This bit will always be read as zero. PSR10 Clear clkT1 clkT0 T1 T0 clkI/O Synchronization Synchronization Bit 7 6 5 4 3 2 1 0 – – – – ACME PUD PSR2 PSR10 SFIOR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 73 8159E–AVR–02/2013 17. 16-bit Timer/Counter1 17.1 Features • True 16-bit Design (i.e., allows 16-bit PWM) • Two Independent Output Compare Units • Double Buffered Output Compare Registers • One Input Capture Unit • Input Capture Noise Canceler • Clear Timer on Compare Match (Auto Reload) • Glitch-free, Phase Correct Pulse Width Modulator (PWM) • Variable PWM Period • Frequency Generator • External Event Counter • Four Independent Interrupt Sources (TOV1, OCF1A, OCF1B, and ICF1) 17.2 Overview The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave generation, and signal timing measurement. Most register and bit references in this section are written in general form. A lower case “n” replaces the Timer/Counter number, and a lower case “x” replaces the Output Compare unit channel. However, when using the register or bit defines in a program, the precise form must be used i.e., TCNT1 for accessing Timer/Counter1 counter value and so on. A simplified block diagram of the 16-bit Timer/Counter is shown in Figure 17-1. For the actual placement of I/O pins, refer to “Pin Configurations” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “Register Description” on page 92.ATmega8A [DATASHEET] 74 8159E–AVR–02/2013 Figure 17-1. 16-bit Timer/Counter Block Diagram(1) Note: 1. Refer to “Pin Configurations” on page 2, Table 13-2 on page 56, and Table 13-8 on page 61 for Timer/Counter1 pin placement and description. 17.2.1 Registers The Timer/Counter (TCNT1), Output Compare Registers (OCR1A/B), and Input Capture Register (ICR1) are all 16-bit registers. Special procedures must be followed when accessing the 16-bit registers. These procedures are described in the section “Accessing 16-bit Registers” on page 75. The Timer/Counter Control Registers (TCCR1A/B) are 8-bit registers and have no CPU access restrictions. Interrupt requests (abbreviated to Int.Req. in the figure) signals are all visible in the Timer Interrupt Flag Register (TIFR). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK). TIFR and TIMSK are not shown in the figure since these registers are shared by other timer units. The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on the T1 pin. The Clock Select logic block controls which clock source and edge the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the clock select logic is referred to as the timer clock (clkT1). The double buffered Output Compare Registers (OCR1A/B) are compared with the Timer/Counter value at all time. The result of the compare can be used by the waveform generator to generate a PWM or variable frequency output on the Output Compare Pin (OC1A/B). See “Output Compare Units” on page 81. The Compare Match event will also set the Compare Match Flag (OCF1A/B) which can be used to generate an Output Compare interrupt request. Clock Select Timer/Counter DATA BUS OCRnA OCRnB ICRn = = TCNTn Waveform Generation Waveform Generation OCnA OCnB Noise Canceler ICPn = Fixed TOP Values Edge Detector Control Logic = 0 TOP BOTTOM Count Clear Direction TOVn (Int. Req.) OCFnA (Int. Req.) OCFnB (Int.Req.) ICFn (Int.Req.) TCCRnA TCCRnB ( From Analog Comparator Ouput ) Tn Edge Detector ( From Prescaler ) clkTnATmega8A [DATASHEET] 75 8159E–AVR–02/2013 The Input Capture Register can capture the Timer/Counter value at a given external (edge triggered) event on either the Input Capture Pin (ICP1) or on the Analog Comparator pins (see “Analog Comparator” on page 179). The Input Capture unit includes a digital filtering unit (Noise Canceler) for reducing the chance of capturing noise spikes. The TOP value, or maximum Timer/Counter value, can in some modes of operation be defined by either the OCR1A Register, the ICR1 Register, or by a set of fixed values. When using OCR1A as TOP value in a PWM mode, the OCR1A Register can not be used for generating a PWM output. However, the TOP value will in this case be double buffered allowing the TOP value to be changed in run time. If a fixed TOP value is required, the ICR1 Register can be used as an alternative, freeing the OCR1A to be used as PWM output. 17.2.2 Definitions The following definitions are used extensively throughout the document: 17.2.3 Compatibility The 16-bit Timer/Counter has been updated and improved from previous versions of the 16-bit AVR Timer/Counter. This 16-bit Timer/Counter is fully compatible with the earlier version regarding: • All 16-bit Timer/Counter related I/O Register address locations, including Timer Interrupt Registers. • Bit locations inside all 16-bit Timer/Counter Registers, including Timer Interrupt Registers. • Interrupt Vectors. • The following control bits have changed name, but have same functionality and register location: • PWM10 is changed to WGM10. • PWM11 is changed to WGM11. • CTC1 is changed to WGM12. The following bits are added to the 16-bit Timer/Counter Control Registers: • FOC1A and FOC1B are added to TCCR1A. • WGM13 is added to TCCR1B. The 16-bit Timer/Counter has improvements that will affect the compatibility in some special cases. 17.3 Accessing 16-bit Registers The TCNT1, OCR1A/B, and ICR1 are 16-bit registers that can be accessed by the AVR CPU via the 8-bit data bus. The 16-bit register must be byte accessed using two read or write operations. The 16-bit timer has a single 8-bit register for temporary storing of the High byte of the 16-bit access. The same temporary register is shared between all 16-bit registers within the 16-bit timer. Accessing the Low byte triggers the 16-bit read or write operation. When the Low byte of a 16-bit register is written by the CPU, the High byte stored in the temporary register, and the Low byte written are both copied into the 16-bit register in the same clock cycle. When the Low byte of a 16-bit register is read by the CPU, the High byte of the 16-bit register is copied into the temporary register in the same clock cycle as the Low byte is read. Table 17-1. Definitions BOTTOM The counter reaches the BOTTOM when it becomes 0x0000. MAX The counter reaches its MAXimum when it becomes 0xFFFF (decimal 65535). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be one of the fixed values: 0x00FF, 0x01FF, or 0x03FF, or to the value stored in the OCR1A or ICR1 Register. The assignment is dependent of the mode of operation.ATmega8A [DATASHEET] 76 8159E–AVR–02/2013 Not all 16-bit accesses uses the temporary register for the High byte. Reading the OCR1A/B 16-bit registers does not involve using the temporary register. To do a 16-bit write, the High byte must be written before the Low byte. For a 16-bit read, the Low byte must be read before the High byte. The following code examples show how to access the 16-bit Timer Registers assuming that no interrupts updates the temporary register. The same principle can be used directly for accessing the OCR1A/B and ICR1 Registers. Note that when using “C”, the compiler handles the 16-bit access. Note: 1. See “About Code Examples” on page 6. The assembly code example returns the TCNT1 value in the r17:r16 Register pair. It is important to notice that accessing 16-bit registers are atomic operations. If an interrupt occurs between the two instructions accessing the 16-bit register, and the interrupt code updates the temporary register by accessing the same or any other of the 16-bit Timer Registers, then the result of the access outside the interrupt will be corrupted. Therefore, when both the main code and the interrupt code update the temporary register, the main code must disable the interrupts during the 16-bit access. Assembly Code Example(1) :. ; Set TCNT1 to 0x01FF ldi r17,0x01 ldi r16,0xFF out TCNT1H,r17 out TCNT1L,r16 ; Read TCNT1 into r17:r16 in r16,TCNT1L in r17,TCNT1H :. C Code Example(1) unsigned int i; :. /* Set TCNT1 to 0x01FF */ TCNT1 = 0x1FF; /* Read TCNT1 into i */ i = TCNT1; :.ATmega8A [DATASHEET] 77 8159E–AVR–02/2013 The following code examples show how to do an atomic read of the TCNT1 Register contents. Reading any of the OCR1A/B or ICR1 Registers can be done by using the same principle. Note: 1. See “About Code Examples” on page 6. The assembly code example returns the TCNT1 value in the r17:r16 Register pair. Assembly Code Example(1) TIM16_ReadTCNT1: ; Save Global Interrupt Flag in r18,SREG ; Disable interrupts cli ; Read TCNT1 into r17:r16 in r16,TCNT1L in r17,TCNT1H ; Restore Global Interrupt Flag out SREG,r18 ret C Code Example(1) unsigned int TIM16_ReadTCNT1( void ) { unsigned char sreg; unsigned int i; /* Save Global Interrupt Flag */ sreg = SREG; /* Disable interrupts */ _CLI(); /* Read TCNT1 into i */ i = TCNT1; /* Restore Global Interrupt Flag */ SREG = sreg; return i; }ATmega8A [DATASHEET] 78 8159E–AVR–02/2013 The following code examples show how to do an atomic write of the TCNT1 Register contents. Writing any of the OCR1A/B or ICR1 Registers can be done by using the same principle. Note: 1. See “About Code Examples” on page 6. The assembly code example requires that the r17:r16 Register pair contains the value to be written to TCNT1. 17.3.1 Reusing the Temporary High Byte Register If writing to more than one 16-bit register where the High byte is the same for all registers written, then the High byte only needs to be written once. However, note that the same rule of atomic operation described previously also applies in this case. 17.4 Timer/Counter Clock Sources The Timer/Counter can be clocked by an internal or an external clock source. The clock source is selected by the clock select logic which is controlled by the clock select (CS12:0) bits located in the Timer/Counter Control Register B (TCCR1B). For details on clock sources and prescaler, see “Timer/Counter0 and Timer/Counter1 Prescalers” on page 71. 17.5 Counter Unit The main part of the 16-bit Timer/Counter is the programmable 16-bit bi-directional counter unit. Figure 17-2 shows a block diagram of the counter and its surroundings. Assembly Code Example(1) TIM16_WriteTCNT1: ; Save Global Interrupt Flag in r18,SREG ; Disable interrupts cli ; Set TCNT1 to r17:r16 out TCNT1H,r17 out TCNT1L,r16 ; Restore Global Interrupt Flag out SREG,r18 ret C Code Example(1) void TIM16_WriteTCNT1( unsigned int i ) { unsigned char sreg; unsigned int i; /* Save Global Interrupt Flag */ sreg = SREG; /* Disable interrupts */ _CLI(); /* Set TCNT1 to i */ TCNT1 = i; /* Restore Global Interrupt Flag */ SREG = sreg; }ATmega8A [DATASHEET] 79 8159E–AVR–02/2013 Figure 17-2. Counter Unit Block Diagram Signal description (internal signals): count Increment or decrement TCNT1 by 1. direction Select between increment and decrement. clear Clear TCNT1 (set all bits to zero). clkT1 Timer/Counter clock. TOP Signalize that TCNT1 has reached maximum value. BOTTOM Signalize that TCNT1 has reached minimum value (zero). The 16-bit counter is mapped into two 8-bit I/O memory locations: counter high (TCNT1H) containing the upper eight bits of the counter, and Counter Low (TCNT1L) containing the lower eight bits. The TCNT1H Register can only be indirectly accessed by the CPU. When the CPU does an access to the TCNT1H I/O location, the CPU accesses the High byte temporary register (TEMP). The temporary register is updated with the TCNT1H value when the TCNT1L is read, and TCNT1H is updated with the temporary register value when TCNT1L is written. This allows the CPU to read or write the entire 16-bit counter value within one clock cycle via the 8-bit data bus. It is important to notice that there are special cases of writing to the TCNT1 Register when the counter is counting that will give unpredictable results. The special cases are described in the sections where they are of importance. Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT1). The clkT1 can be generated from an external or internal clock source, selected by the clock select bits (CS12:0). When no clock source is selected (CS12:0 = 0) the timer is stopped. However, the TCNT1 value can be accessed by the CPU, independent of whether clkT1 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the Waveform Generation mode bits (WGM13:0) located in the Timer/Counter Control Registers A and B (TCCR1A and TCCR1B). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare Outputs OC1x. For more details about advanced counting sequences and waveform generation, see “Modes of Operation” on page 84. The Timer/Counter Overflow (TOV1) fLag is set according to the mode of operation selected by the WGM13:0 bits. TOV1 can be used for generating a CPU interrupt. 17.6 Input Capture Unit The Timer/Counter incorporates an Input Capture unit that can capture external events and give them a timestamp indicating time of occurrence. The external signal indicating an event, or multiple events, can be applied via the ICP1 pin or alternatively, via the Analog Comparator unit. The time-stamps can then be used to calculate freTEMP (8-bit) DATA BUS (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) Control Logic count clear direction TOVn (Int. Req.) Clock Select TOP BOTTOM Tn Edge Detector ( From Prescaler ) clkTnATmega8A [DATASHEET] 80 8159E–AVR–02/2013 quency, duty-cycle, and other features of the signal applied. Alternatively the time-stamps can be used for creating a log of the events. The Input Capture unit is illustrated by the block diagram shown in Figure 17-3. The elements of the block diagram that are not directly a part of the Input Capture unit are gray shaded. The small “n” in register and bit names indicates the Timer/Counter number. Figure 17-3. Input Capture Unit Block Diagram When a change of the logic level (an event) occurs on the Input Capture Pin (ICP1), alternatively on the Analog Comparator Output (ACO), and this change confirms to the setting of the edge detector, a capture will be triggered. When a capture is triggered, the 16-bit value of the counter (TCNT1) is written to the Input Capture Register (ICR1). The Input Capture Flag (ICF1) is set at the same system clock as the TCNT1 value is copied into ICR1 Register. If enabled (TICIE1 = 1), the Input Capture Flag generates an Input Capture interrupt. The ICF1 Flag is automatically cleared when the interrupt is executed. Alternatively the ICF1 Flag can be cleared by software by writing a logical one to its I/O bit location. Reading the 16-bit value in the Input Capture Register (ICR1) is done by first reading the Low byte (ICR1L) and then the High byte (ICR1H). When the Low byte is read the High byte is copied into the High byte temporary register (TEMP). When the CPU reads the ICR1H I/O location it will access the TEMP Register. The ICR1 Register can only be written when using a Waveform Generation mode that utilizes the ICR1 Register for defining the counter’s TOP value. In these cases the Waveform Generation mode (WGM13:0) bits must be set before the TOP value can be written to the ICR1 Register. When writing the ICR1 Register the High byte must be written to the ICR1H I/O location before the Low byte is written to ICR1L. For more information on how to access the 16-bit registers refer to “Accessing 16-bit Registers” on page 75. 17.6.1 Input Capture Pin Source The main trigger source for the Input Capture unit is the Input Capture Pin (ICP1). Timer/Counter 1 can alternatively use the Analog Comparator Output as trigger source for the Input Capture unit. The Analog Comparator is selected as trigger source by setting the Analog Comparator Input Capture (ACIC) bit in the Analog Comparator ICFn (Int. Req.) Analog Comparator WRITE ICRn (16-bit Register) ICRnH (8-bit) Noise Canceler ICPn Edge Detector TEMP (8-bit) DATA BUS (8-bit) ICRnL (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) ACO* ACIC* ICNC ICESATmega8A [DATASHEET] 81 8159E–AVR–02/2013 Control and Status Register (ACSR). Be aware that changing trigger source can trigger a capture. The Input Capture Flag must therefore be cleared after the change. Both the Input Capture Pin (ICP1) and the Analog Comparator Output (ACO) inputs are sampled using the same technique as for the T1 pin (Figure 16-1 on page 71). The edge detector is also identical. However, when the noise canceler is enabled, additional logic is inserted before the edge detector, which increases the delay by four system clock cycles. Note that the input of the noise canceler and edge detector is always enabled unless the Timer/Counter is set in a Waveform Generation mode that uses ICR1 to define TOP. An Input Capture can be triggered by software by controlling the port of the ICP1 pin. 17.6.2 Noise Canceler The noise canceler improves noise immunity by using a simple digital filtering scheme. The noise canceler input is monitored over four samples, and all four must be equal for changing the output that in turn is used by the edge detector. The noise canceler is enabled by setting the Input Capture Noise Canceler (ICNC1) bit in Timer/Counter Control Register B (TCCR1B). When enabled the noise canceler introduces additional four system clock cycles of delay from a change applied to the input, to the update of the ICR1 Register. The noise canceler uses the system clock and is therefore not affected by the prescaler. 17.6.3 Using the Input Capture Unit The main challenge when using the Input Capture unit is to assign enough processor capacity for handling the incoming events. The time between two events is critical. If the processor has not read the captured value in the ICR1 Register before the next event occurs, the ICR1 will be overwritten with a new value. In this case the result of the capture will be incorrect. When using the Input Capture interrupt, the ICR1 Register should be read as early in the interrupt handler routine as possible. Even though the Input Capture interrupt has relatively high priority, the maximum interrupt response time is dependent on the maximum number of clock cycles it takes to handle any of the other interrupt requests. Using the Input Capture unit in any mode of operation when the TOP value (resolution) is actively changed during operation, is not recommended. Measurement of an external signal’s duty cycle requires that the trigger edge is changed after each capture. Changing the edge sensing must be done as early as possible after the ICR1 Register has been read. After a change of the edge, the Input Capture Flag (ICF1) must be cleared by software (writing a logical one to the I/O bit location). For measuring frequency only, the clearing of the ICF1 Flag is not required (if an interrupt handler is used). 17.7 Output Compare Units The 16-bit comparator continuously compares TCNT1 with the Output Compare Register (OCR1x). If TCNT equals OCR1x the comparator signals a match. A match will set the Output Compare Flag (OCF1x) at the next timer clock cycle. If enabled (OCIE1x = 1), the Output Compare Flag generates an Output Compare interrupt. The OCF1x Flag is automatically cleared when the interrupt is executed. Alternatively the OCF1x Flag can be cleared by software by writing a logical one to its I/O bit location. The waveform generator uses the match signal to generate an output according to operating mode set by the Waveform Generation mode (WGM13:0) bits and Compare Output mode (COM1x1:0) bits. The TOP and BOTTOM signals are used by the waveform generator for handling the special cases of the extreme values in some modes of operation (See “Modes of Operation” on page 84.) A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (i.e. counter resolution). In addition to the counter resolution, the TOP value defines the period time for waveforms generated by the waveform generator.ATmega8A [DATASHEET] 82 8159E–AVR–02/2013 Figure 17-4 shows a block diagram of the Output Compare unit. The small “n” in the register and bit names indicates the device number (n = 1 for Timer/Counter 1), and the “x” indicates Output Compare unit (A/B). The elements of the block diagram that are not directly a part of the Output Compare unit are gray shaded. Figure 17-4. Output Compare Unit, Block Diagram The OCR1x Register is double buffered when using any of the twelve Pulse Width Modulation (PWM) modes. For the normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR1x Compare Register to either TOP or BOTTOM of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR1x Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR1x Buffer Register, and if double buffering is disabled the CPU will access the OCR1x directly. The content of the OCR1x (Buffer or Compare) Register is only changed by a write operation (the Timer/Counter does not update this register automatically as the TCNT1 and ICR1 Register). Therefore OCR1x is not read via the High byte temporary register (TEMP). However, it is a good practice to read the Low byte first as when accessing other 16-bit registers. Writing the OCR1x Registers must be done via the TEMP Register since the compare of all 16-bit is done continuously. The High byte (OCR1xH) has to be written first. When the High byte I/O location is written by the CPU, the TEMP Register will be updated by the value written. Then when the Low byte (OCR1xL) is written to the lower eight bits, the High byte will be copied into the upper 8-bits of either the OCR1x buffer or OCR1x Compare Register in the same system clock cycle. For more information of how to access the 16-bit registers refer to “Accessing 16-bit Registers” on page 75. 17.7.1 Force Output Compare In non-PWM Waveform Generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC1x) bit. Forcing Compare Match will not set the OCF1x Flag or reload/clear the timer, but the OC1x pin will be updated as if a real Compare Match had occurred (the COM1x1:0 bits settings define whether the OC1x pin is set, cleared or toggled). OCFnx (Int.Req.) = (16-bit Comparator ) OCRnx Buffer (16-bit Register) OCRnxH Buf. (8-bit) OCnx TEMP (8-bit) DATA BUS (8-bit) OCRnxL Buf. (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) WGMn3:0 COMnx1:0 OCRnx (16-bit Register) OCRnxH (8-bit) OCRnxL (8-bit) Waveform Generator TOP BOTTOMATmega8A [DATASHEET] 83 8159E–AVR–02/2013 17.7.2 Compare Match Blocking by TCNT1 Write All CPU writes to the TCNT1 Register will block any Compare Match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR1x to be initialized to the same value as TCNT1 without triggering an interrupt when the Timer/Counter clock is enabled. 17.7.3 Using the Output Compare Unit Since writing TCNT1 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT1 when using any of the Output Compare channels, independent of whether the Timer/Counter is running or not. If the value written to TCNT1 equals the OCR1x value, the Compare Match will be missed, resulting in incorrect waveform generation. Do not write the TCNT1 equal to TOP in PWM modes with variable TOP values. The Compare Match for the TOP will be ignored and the counter will continue to 0xFFFF. Similarly, do not write the TCNT1 value equal to BOTTOM when the counter is downcounting. The setup of the OC1x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC1x value is to use the Force Output Compare (FOC1x) strobe bits in Normal mode. The OC1x Register keeps its value even when changing between Waveform Generation modes. Be aware that the COM1x1:0 bits are not double buffered together with the compare value. Changing the COM1x1:0 bits will take effect immediately. 17.8 Compare Match Output Unit The Compare Output mode (COM1x1:0) bits have two functions. The waveform generator uses the COM1x1:0 bits for defining the Output Compare (OC1x) state at the next Compare Match. Secondly the COM1x1:0 bits control the OC1x pin output source. Figure 17-5 shows a simplified schematic of the logic affected by the COM1x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM1x1:0 bits are shown. When referring to the OC1x state, the reference is for the internal OC1x Register, not the OC1x pin. If a System Reset occur, the OC1x Register is reset to “0”. Figure 17-5. Compare Match Output Unit, Schematic PORT DDR D Q D Q OCnx OCnx Pin D Q Waveform Generator COMnx1 COMnx0 0 1 DATABUS FOCnx clkI/OATmega8A [DATASHEET] 84 8159E–AVR–02/2013 The general I/O port function is overridden by the Output Compare (OC1x) from the waveform generator if either of the COM1x1:0 bits are set. However, the OC1x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC1x pin (DDR_OC1x) must be set as output before the OC1x value is visible on the pin. The port override function is generally independent of the Waveform Generation mode, but there are some exceptions. Refer to Table 17-2, Table 17-3 and Table 17-4 for details. The design of the Output Compare Pin logic allows initialization of the OC1x state before the output is enabled. Note that some COM1x1:0 bit settings are reserved for certain modes of operation. See “Register Description” on page 92. The COM1x1:0 bits have no effect on the Input Capture unit. 17.8.1 Compare Output Mode and Waveform Generation The waveform generator uses the COM1x1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM1x1:0 = 0 tells the waveform generator that no action on the OC1x Register is to be performed on the next Compare Match. For compare output actions in the non-PWM modes refer to Table 17-2 on page 93. For fast PWM mode refer to Table 17-3 on page 93, and for phase correct and phase and frequency correct PWM refer to Table 17-4 on page 93. A change of the COM1x1:0 bits state will have effect at the first Compare Match after the bits are written. For nonPWM modes, the action can be forced to have immediate effect by using the FOC1x strobe bits. 17.9 Modes of Operation The mode of operation (i.e., the behavior of the Timer/Counter and the Output Compare pins) is defined by the combination of the Waveform Generation mode (WGM13:0) and Compare Output mode (COM1x1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM1x1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM1x1:0 bits control whether the output should be set, cleared or toggle at a Compare Match. See “Compare Match Output Unit” on page 83. For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 91. 17.9.1 Normal Mode The simplest mode of operation is the Normal mode (WGM13:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 16-bit value (MAX = 0xFFFF) and then restarts from the BOTTOM (0x0000). In normal operation the Timer/Counter Overflow Flag (TOV1) will be set in the same timer clock cycle as the TCNT1 becomes zero. The TOV1 Flag in this case behaves like a 17th bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV1 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Input Capture unit is easy to use in Normal mode. However, observe that the maximum interval between the external events must not exceed the resolution of the counter. If the interval between events are too long, the timer overflow interrupt or the prescaler must be used to extend the resolution for the capture unit. The Output Compare units can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 17.9.2 Clear Timer on Compare Match (CTC) Mode In Clear Timer on Compare or CTC mode (WGM13:0 = 4 or 12), the OCR1A or ICR1 Register are used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT1) matches either the OCR1A (WGM13:0 = 4) or the ICR1 (WGM13:0 = 12). The OCR1A or ICR1 define the top value for theATmega8A [DATASHEET] 85 8159E–AVR–02/2013 counter, hence also its resolution. This mode allows greater control of the Compare Match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 17-6. The counter value (TCNT1) increases until a Compare Match occurs with either OCR1A or ICR1, and then counter (TCNT1) is cleared. Figure 17-6. CTC Mode, Timing Diagram An interrupt can be generated at each time the counter value reaches the TOP value by either using the OCF1A or ICF1 Flag according to the register used to define the TOP value. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR1A or ICR1 is lower than the current value of TCNT1, the counter will miss the Compare Match. The counter will then have to count to its maximum value (0xFFFF) and wrap around starting at 0x0000 before the Compare Match can occur. In many cases this feature is not desirable. An alternative will then be to use the fast PWM mode using OCR1A for defining TOP (WGM13:0 = 15) since the OCR1A then will be double buffered. For generating a waveform output in CTC mode, the OC1A output can be set to toggle its logical level on each Compare Match by setting the Compare Output mode bits to toggle mode (COM1A1:0 = 1). The OC1A value will not be visible on the port pin unless the data direction for the pin is set to output (DDR_OC1A = 1). The waveform generated will have a maximum frequency of fOC1A = fclk_I/O/2 when OCR1A is set to zero (0x0000). The waveform frequency is defined by the following equation: The N variable represents the prescaler factor (1, 8, 64, 256, or 1024). As for the Normal mode of operation, the TOV1 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x0000. 17.9.3 Fast PWM Mode The fast Pulse Width Modulation or fast PWM mode (WGM13:0 = 5, 6, 7, 14, or 15) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM options by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the Compare Match between TCNT1 and OCR1x, and set at BOTTOM. In inverting Compare Output mode output is set on Compare Match and cleared at BOTTOM. Due to the singleslope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct and phase and frequency correct PWM modes that use dual-slope operation. This high frequency makes the fast PWM TCNTn OCnA (Toggle) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 (COMnA1:0 = 1) f OCnA f clk_I/O 2   N   1 + OCRnA = --------------------------------------------------ATmega8A [DATASHEET] 86 8159E–AVR–02/2013 mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), hence reduces total system cost. The PWM resolution for fast PWM can be fixed to 8-, 9-, or 10-bit, or defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated by using the following equation: In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGM13:0 = 5, 6, or 7), the value in ICR1 (WGM13:0 = 14), or the value in OCR1A (WGM13:0 = 15). The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 17-7. The figure shows fast PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a Compare Match occurs. Figure 17-7. Fast PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set each time the counter reaches TOP. In addition the OCF1A or ICF1 Flag is set at the same timer clock cycle as TOV1 is set when either OCR1A or ICR1 is used for defining the TOP value. If one of the interrupts are enabled, the interrupt handler routine can be used for updating the TOP and compare values. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a Compare Match will never occur between the TCNT1 and the OCR1x. Note that when using fixed TOP values the unused bits are masked to zero when any of the OCR1x Registers are written. The procedure for updating ICR1 differs from updating OCR1A when used for defining the TOP value. The ICR1 Register is not double buffered. This means that if ICR1 is changed to a low value when the counter is running with none or a low prescaler value, there is a risk that the new ICR1 value written is lower than the current value of TCNT1. The result will then be that the counter will miss the Compare Match at the TOP value. The counter will then have to count to the MAX value (0xFFFF) and wrap around starting at 0x0000 before the Compare Match can occur. The OCR1A Register, however, is double buffered. This feature allows the OCR1A I/O location to be written anytime. When the OCR1A I/O location is written the value written will be put into the OCR1A Buffer Register. The OCR1A Compare Register will then be updated with the value in the Buffer Register at the next timer clock cycle RFPWM log  TOP + 1 log  2 = ----------------------------------- TCNTn OCRnx / TOP Update and TOVn Interrupt Flag Set and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 5 6 7 8 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)ATmega8A [DATASHEET] 87 8159E–AVR–02/2013 the TCNT1 matches TOP. The update is done at the same timer clock cycle as the TCNT1 is cleared and the TOV1 Flag is set. Using the ICR1 Register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A Register is free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed (by changing the TOP value), using the OCR1A as TOP is clearly a better choice due to its double buffer feature. In fast PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to 3. See Table 17-3 on page 93. The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the Compare Match between OCR1x and TCNT1, and clearing (or setting) the OC1x Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represents special cases when generating a PWM waveform output in the fast PWM mode. If the OCR1x is set equal to BOTTOM (0x0000) the output will be a narrow spike for each TOP+1 timer clock cycle. Setting the OCR1x equal to TOP will result in a constant high or low output (depending on the polarity of the output set by the COM1x1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC1A to toggle its logical level on each Compare Match (COM1A1:0 = 1). This applies only if OCR1A is used to define the TOP value (WGM13:0 = 15). The waveform generated will have a maximum frequency of fOC1A = fclk_I/O/2 when OCR1A is set to zero (0x0000). This feature is similar to the OC1A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 17.9.4 Phase Correct PWM Mode The phase correct Pulse Width Modulation or phase correct PWM mode (WGM13:0 = 1, 2, 3, 10, or 11) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is, like the phase and frequency correct PWM mode, based on a dual-slope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the Compare Match between TCNT1 and OCR1x while upcounting, and set on the Compare Match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode can be fixed to 8-, 9-, or 10-bit, or defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated by using the following equation: In phase correct PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGM13:0 = 1, 2, or 3), the value in ICR1 (WGM13:0 = 10), or the value in OCR1A (WGM13:0 = 11). The counter has then reached the TOP and changes the count direction. The TCNT1 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 17-8. The figure shows phase correct PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent f OCnxPWM f clk_I/O N    1 + TOP = ----------------------------------- RPCPWM log  TOP + 1 log  2 = -----------------------------------ATmega8A [DATASHEET] 88 8159E–AVR–02/2013 compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a Compare Match occurs. Figure 17-8. Phase Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set each time the counter reaches BOTTOM. When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 Flag is set accordingly at the same timer clock cycle as the OCR1x Registers are updated with the double buffer value (at TOP). The Interrupt Flags can be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a Compare Match will never occur between the TCNT1 and the OCR1x. Note that when using fixed TOP values, the unused bits are masked to zero when any of the OCR1x Registers are written. As the third period shown in Figure 17-8 illustrates, changing the TOP actively while the Timer/Counter is running in the Phase Correct mode can result in an unsymmetrical output. The reason for this can be found in the time of update of the OCR1x Register. Since the OCR1x update occurs at TOP, the PWM period starts and ends at TOP. This implies that the length of the falling slope is determined by the previous TOP value, while the length of the rising slope is determined by the new TOP value. When these two values differ the two slopes of the period will differ in length. The difference in length gives the unsymmetrical result on the output. It is recommended to use the Phase and Frequency Correct mode instead of the Phase Correct mode when changing the TOP value while the Timer/Counter is running. When using a static TOP value there are practically no differences between the two modes of operation. In phase correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to 3. See Table 17-4 on page 93. The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the Compare Match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x Register at Compare Match between OCR1x and TCNT1 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: OCRnx / TOP Update and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) 1 2 3 4 TOVn Interrupt Flag Set (Interrupt on Bottom) TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) f OCnxPCPWM f clk_I/O 2   N TOP = ----------------------------ATmega8A [DATASHEET] 89 8159E–AVR–02/2013 The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WMG13:0 = 11) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. 17.9.5 Phase and Frequency Correct PWM Mode The phase and frequency correct Pulse Width Modulation, or phase and frequency correct PWM mode (WGM13:0 = 8 or 9) provides a high resolution phase and frequency correct PWM waveform generation option. The phase and frequency correct PWM mode is, like the phase correct PWM mode, based on a dual-slope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the Compare Match between TCNT1 and OCR1x while upcounting, and set on the Compare Match while downcounting. In inverting Compare Output mode, the operation is inverted. The dual-slope operation gives a lower maximum operation frequency compared to the single-slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The main difference between the phase correct, and the phase and frequency correct PWM mode is the time the OCR1x Register is updated by the OCR1x Buffer Register, (see Figure 17-8 and Figure 17-9). The PWM resolution for the phase and frequency correct PWM mode can be defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated using the following equation: In phase and frequency correct PWM mode the counter is incremented until the counter value matches either the value in ICR1 (WGM13:0 = 8), or the value in OCR1A (WGM13:0 = 9). The counter has then reached the TOP and changes the count direction. The TCNT1 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct and frequency correct PWM mode is shown on Figure 17-9. The figure shows phase and frequency correct PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a Compare Match occurs. RPFCPWM log  TOP + 1 log  2 = -----------------------------------ATmega8A [DATASHEET] 90 8159E–AVR–02/2013 Figure 17-9. Phase and Frequency Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set at the same timer clock cycle as the OCR1x Registers are updated with the double buffer value (at BOTTOM). When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 Flag set when TCNT1 has reached TOP. The Interrupt Flags can then be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a Compare Match will never occur between the TCNT1 and the OCR1x. As Figure 17-9 shows the output generated is, in contrast to the Phase Correct mode, symmetrical in all periods. Since the OCR1x Registers are updated at BOTTOM, the length of the rising and the falling slopes will always be equal. This gives symmetrical output pulses and is therefore frequency correct. Using the ICR1 Register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A Register is free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed by changing the TOP value, using the OCR1A as TOP is clearly a better choice due to its double buffer feature. In phase and frequency correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to 3. See Table 17-4 on page 93. The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the Compare Match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x Register at Compare Match between OCR1x and TCNT1 when the counter decrements. The PWM frequency for the output when using phase and frequency correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represents special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be set to high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. OCRnx / TOP Update and TOVn Interrupt Flag Set (Interrupt on Bottom) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) 1 2 3 4 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) f OCnxPFCPWM f clk_I/O 2   N TOP = ----------------------------ATmega8A [DATASHEET] 91 8159E–AVR–02/2013 If OCR1A is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. 17.10 Timer/Counter Timing Diagrams The Timer/Counter is a synchronous design and the timer clock (clkT1) is therefore shown as a clock enable signal in the following figures. The figures include information on when Interrupt Flags are set, and when the OCR1x Register is updated with the OCR1x buffer value (only for modes utilizing double buffering). Figure 17-10 shows a timing diagram for the setting of OCF1x. Figure 17-10. Timer/Counter Timing Diagram, Setting of OCF1x, no Prescaling Figure 17-11 shows the same timing data, but with the prescaler enabled. Figure 17-11. Timer/Counter Timing Diagram, Setting of OCF1x, with Prescaler (fclk_I/O/8) Figure 17-12 shows the count sequence close to TOP in various modes. When using phase and frequency correct PWM mode the OCR1x Register is updated at BOTTOM. The timing diagrams will be the same, but TOP should be replaced by BOTTOM, TOP-1 by BOTTOM+1 and so on. The same renaming applies for modes that set the TOV1 Flag at BOTTOM. clkTn (clkI/O/1) OCFnx clkI/O OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 OCFnx OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8)ATmega8A [DATASHEET] 92 8159E–AVR–02/2013 Figure 17-12. Timer/Counter Timing Diagram, no Prescaling Figure 17-13 shows the same timing data, but with the prescaler enabled. Figure 17-13. Timer/Counter Timing Diagram, with Prescaler (fclk_I/O/8) 17.11 Register Description 17.11.1 TCCR1A – Timer/Counter 1 Control Register A • Bit 7:6 – COM1A1:0: Compare Output Mode for channel A • Bit 5:4 – COM1B1:0: Compare Output Mode for channel B The COM1A1:0 and COM1B1:0 control the Output Compare Pins (OC1A and OC1B respectively) behavior. If one or both of the COM1A1:0 bits are written to one, the OC1A output overrides the normal port functionality of the I/O TOVn (FPWM) and ICFn (if used as TOP) OCRnx (Update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx Value New OCRnx Value TOP - 1 TOP BOTTOM BOTTOM + 1 clkTn (clkI/O/1) clkI/O TOVn (FPWM) and ICFn (if used as TOP) OCRnx (Update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx Value New OCRnx Value TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) Bit 7 6 5 4 3 2 1 0 COM1A1 COM1A0 COM1B1 COM1B0 FOC1A FOC1B WGM11 WGM10 TCCR1A Read/Write R/W R/W R/W R/W W W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 93 8159E–AVR–02/2013 pin it is connected to. If one or both of the COM1B1:0 bit are written to one, the OC1B output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC1A or OC1B pin must be set in order to enable the output driver. When the OC1A or OC1B is connected to the pin, the function of the COM1x1:0 bits is dependent of the WGM13:0 bits setting. Table 17-2 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to a normal or a CTC mode (non-PWM). Table 17-3 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the fast PWM mode. Note: 1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. In this case the Compare Match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on page 85. for more details. Table 17-4 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the phase correct or the phase and frequency correct, PWM mode. Note: 1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. See “Phase Correct PWM Mode” on page 87. for more details. Table 17-2. Compare Output Mode, Non-PWM COM1A1/ COM1B1 COM1A0/ COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 Toggle OC1A/OC1B on Compare Match 1 0 Clear OC1A/OC1B on Compare Match (Set output to low level) 1 1 Set OC1A/OC1B on Compare Match (Set output to high level) Table 17-3. Compare Output Mode, Fast PWM(1) COM1A1/ COM1B1 COM1A0/ COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 WGM13:0 = 15: Toggle OC1A on Compare Match, OC1B disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B disconnected. 1 0 Clear OC1A/OC1B on Compare Match, set OC1A/OC1B at BOTTOM, (non-inverting mode) 1 1 Set OC1A/OC1B on Compare Match, clear OC1A/OC1B at BOTTOM, (inverting mode) Table 17-4. Compare Output Mode, Phase Correct and Phase and Frequency Correct PWM(1) COM1A1/ COM1B1 COM1A0/ COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 WGM13:0 = 9 or 14: Toggle OC1A on Compare Match, OC1B disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B disconnected. 1 0 Clear OC1A/OC1B on Compare Match when up-counting. Set OC1A/OC1B on Compare Match when downcounting. 1 1 Set OC1A/OC1B on Compare Match when up-counting. Clear OC1A/OC1B on Compare Match when downcounting.ATmega8A [DATASHEET] 94 8159E–AVR–02/2013 • Bit 3 – FOC1A: Force Output Compare for channel A • Bit 2 – FOC1B: Force Output Compare for channel B The FOC1A/FOC1B bits are only active when the WGM13:0 bits specifies a non-PWM mode. However, for ensuring compatibility with future devices, these bits must be set to zero when TCCR1A is written when operating in a PWM mode. When writing a logical one to the FOC1A/FOC1B bit, an immediate Compare Match is forced on the waveform generation unit. The OC1A/OC1B output is changed according to its COM1x1:0 bits setting. Note that the FOC1A/FOC1B bits are implemented as strobes. Therefore it is the value present in the COM1x1:0 bits that determine the effect of the forced compare. A FOC1A/FOC1B strobe will not generate any interrupt nor will it clear the timer in Clear Timer on Compare Match (CTC) mode using OCR1A as TOP. The FOC1A/FOC1B bits are always read as zero. • Bit 1:0 – WGM11:0: Waveform Generation Mode Combined with the WGM13:2 bits found in the TCCR1B Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 17-5. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and three types of Pulse Width Modulation (PWM) modes. (See “Modes of Operation” on page 84.) Note: 1. The CTC1 and PWM11:0 bit definition names are obsolete. Use the WGM12:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer. Table 17-5. Waveform Generation Mode Bit Description Mode WGM13 WGM12 (CTC1) WGM11 (PWM11) WGM10 (PWM10) Timer/Counter Mode of Operation(1) TOP Update of OCR1x TOV1 Flag Set on 0 0 0 0 0 Normal 0xFFFF Immediate MAX 1 0 0 0 1 PWM, Phase Correct, 8-bit 0x00FF TOP BOTTOM 2 0 0 1 0 PWM, Phase Correct, 9-bit 0x01FF TOP BOTTOM 3 0 0 1 1 PWM, Phase Correct, 10-bit 0x03FF TOP BOTTOM 4 0 1 0 0 CTC OCR1A Immediate MAX 5 0 1 0 1 Fast PWM, 8-bit 0x00FF BOTTOM TOP 6 0 1 1 0 Fast PWM, 9-bit 0x01FF BOTTOM TOP 7 0 1 1 1 Fast PWM, 10-bit 0x03FF BOTTOM TOP 8 1 0 0 0 PWM, Phase and Frequency Correct ICR1 BOTTOM BOTTOM 9 1 0 0 1 PWM, Phase and Frequency Correct OCR1A BOTTOM BOTTOM 10 1 0 1 0 PWM, Phase Correct ICR1 TOP BOTTOM 11 1 0 1 1 PWM, Phase Correct OCR1A TOP BOTTOM 12 1 1 0 0 CTC ICR1 Immediate MAX 13 1 1 0 1 (Reserved) – – – 14 1 1 1 0 Fast PWM ICR1 BOTTOM TOP 15 1 1 1 1 Fast PWM OCR1A BOTTOM TOPATmega8A [DATASHEET] 95 8159E–AVR–02/2013 17.11.2 TCCR1B – Timer/Counter 1 Control Register B • Bit 7 – ICNC1: Input Capture Noise Canceler Setting this bit (to one) activates the Input Capture Noise Canceler. When the noise canceler is activated, the input from the Input Capture Pin (ICP1) is filtered. The filter function requires four successive equal valued samples of the ICP1 pin for changing its output. The Input Capture is therefore delayed by four Oscillator cycles when the noise canceler is enabled. • Bit 6 – ICES1: Input Capture Edge Select This bit selects which edge on the Input Capture Pin (ICP1) that is used to trigger a capture event. When the ICES1 bit is written to zero, a falling (negative) edge is used as trigger, and when the ICES1 bit is written to one, a rising (positive) edge will trigger the capture. When a capture is triggered according to the ICES1 setting, the counter value is copied into the Input Capture Register (ICR1). The event will also set the Input Capture Flag (ICF1), and this can be used to cause an Input Capture Interrupt, if this interrupt is enabled. When the ICR1 is used as TOP value (see description of the WGM13:0 bits located in the TCCR1A and the TCCR1B Register), the ICP1 is disconnected and consequently the Input Capture function is disabled. • Bit 5 – Reserved Bit This bit is reserved for future use. For ensuring compatibility with future devices, this bit must be written to zero when TCCR1B is written. • Bit 4:3 – WGM13:2: Waveform Generation Mode See TCCR1A Register description. • Bit 2:0 – CS12:0: Clock Select The three clock select bits select the clock source to be used by the Timer/Counter, see Figure 17-10 and Figure 17-11. If external pin modes are used for the Timer/Counter1, transitions on the T1 pin will clock the counter even if the pin is configured as an output. This feature allows software control of the counting. Bit 7 6 5 4 3 2 1 0 ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 TCCR1B Read/Write R/W R/W R R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 17-6. Clock Select Bit Description CS12 CS11 CS10 Description 0 0 0 No clock source. (Timer/Counter stopped) 0 0 1 clkI/O/1 (No prescaling) 0 1 0 clkI/O/8 (From prescaler) 0 1 1 clkI/O/64 (From prescaler) 1 0 0 clkI/O/256 (From prescaler) 1 0 1 clkI/O/1024 (From prescaler) 1 1 0 External clock source on T1 pin. Clock on falling edge. 1 1 1 External clock source on T1 pin. Clock on rising edge.ATmega8A [DATASHEET] 96 8159E–AVR–02/2013 17.11.3 TCNT1H and TCNT1L – Timer/Counter 1 The two Timer/Counter I/O locations (TCNT1H and TCNT1L, combined TCNT1) give direct access, both for read and for write operations, to the Timer/Counter unit 16-bit counter. To ensure that both the high and Low bytes are read and written simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 75. Modifying the counter (TCNT1) while the counter is running introduces a risk of missing a Compare Match between TCNT1 and one of the OCR1x Registers. Writing to the TCNT1 Register blocks (removes) the Compare Match on the following timer clock for all compare units. 17.11.4 OCR1AH and OCR1AL– Output Compare Register 1 A 17.11.5 OCR1BH and OCR1BL – Output Compare Register 1 B The Output Compare Registers contain a 16-bit value that is continuously compared with the counter value (TCNT1). A match can be used to generate an Output Compare Interrupt, or to generate a waveform output on the OC1x pin. The Output Compare Registers are 16-bit in size. To ensure that both the high and Low bytes are written simultaneously when the CPU writes to these registers, the access is performed using an 8-bit temporary High byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 75. 17.11.6 ICR1H and ICR1L – Input Capture Register 1 The Input Capture is updated with the counter (TCNT1) value each time an event occurs on the ICP1 pin (or optionally on the Analog Comparator Output for Timer/Counter1). The Input Capture can be used for defining the counter TOP value. The Input Capture Register is 16-bit in size. To ensure that both the high and Low bytes are read simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High byte Register Bit 7 6 5 4 3 2 1 0 TCNT1[15:8] TCNT1H TCNT1[7:0] TCNT1L Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1A[15:8] OCR1AH OCR1A[7:0] OCR1AL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1B[15:8] OCR1BH OCR1B[7:0] OCR1BL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 ICR1[15:8] ICR1H ICR1[7:0] ICR1L Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 97 8159E–AVR–02/2013 (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 75. 17.11.7 TIMSK(1) – Timer/Counter Interrupt Mask Register Note: 1. This register contains interrupt control bits for several Timer/Counters, but only Timer1 bits are described in this section. The remaining bits are described in their respective timer sections. • Bit 5 – TICIE1: Timer/Counter1, Input Capture Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Input Capture Interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 44) is executed when the ICF1 Flag, located in TIFR, is set. • Bit 4 – OCIE1A: Timer/Counter1, Output Compare A Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Output Compare A match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 44) is executed when the OCF1A Flag, located in TIFR, is set. • Bit 3 – OCIE1B: Timer/Counter1, Output Compare B Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Output Compare B match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 44) is executed when the OCF1B Flag, located in TIFR, is set. • Bit 2 – TOIE1: Timer/Counter1, Overflow Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Overflow Interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 44) is executed when the TOV1 Flag, located in TIFR, is set. 17.11.8 TIFR(1) – Timer/Counter Interrupt Flag Register Note: 1. This register contains flag bits for several Timer/Counters, but only Timer1 bits are described in this section. The remaining bits are described in their respective timer sections. • Bit 5 – ICF1: Timer/Counter1, Input Capture Flag This flag is set when a capture event occurs on the ICP1 pin. When the Input Capture Register (ICR1) is set by the WGM13:0 to be used as the TOP value, the ICF1 Flag is set when the counter reaches the TOP value. ICF1 is automatically cleared when the Input Capture Interrupt Vector is executed. Alternatively, ICF1 can be cleared by writing a logic one to its bit location. • Bit 4 – OCF1A: Timer/Counter1, Output Compare A Match Flag This flag is set in the timer clock cycle after the counter (TCNT1) value matches the Output Compare Register A (OCR1A). Note that a Forced Output Compare (FOC1A) strobe will not set the OCF1A Flag. Bit 7 6 5 4 3 2 1 0 OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 TIMSK Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 TIFR Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 98 8159E–AVR–02/2013 OCF1A is automatically cleared when the Output Compare Match A Interrupt Vector is executed. Alternatively, OCF1A can be cleared by writing a logic one to its bit location. • Bit 3 – OCF1B: Timer/Counter1, Output Compare B Match Flag This flag is set in the timer clock cycle after the counter (TCNT1) value matches the Output Compare Register B (OCR1B). Note that a Forced Output Compare (FOC1B) strobe will not set the OCF1B Flag. OCF1B is automatically cleared when the Output Compare Match B Interrupt Vector is executed. Alternatively, OCF1B can be cleared by writing a logic one to its bit location. • Bit 2 – TOV1: Timer/Counter1, Overflow Flag The setting of this flag is dependent of the WGM13:0 bits setting. In normal and CTC modes, the TOV1 Flag is set when the timer overflows. Refer to Table 17-5 on page 94 for the TOV1 Flag behavior when using another WGM13:0 bit setting. TOV1 is automatically cleared when the Timer/Counter1 Overflow Interrupt Vector is executed. Alternatively, TOV1 can be cleared by writing a logic one to its bit location.ATmega8A [DATASHEET] 99 8159E–AVR–02/2013 18. 8-bit Timer/Counter2 with PWM and Asynchronous Operation 18.1 Features • Single Channel Counter • Clear Timer on Compare Match (Auto Reload) • Glitch-free, phase Correct Pulse Width Modulator (PWM) • Frequency Generator • 10-bit Clock Prescaler • Overflow and Compare Match Interrupt Sources (TOV2 and OCF2) • Allows Clocking from External 32kHz Watch Crystal Independent of the I/O Clock 18.2 Overview Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 18-1. For the actual placement of I/O pins, refer to “Pin Configurations” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “Register Description” on page 112. Figure 18-1. 8-bit Timer/Counter Block Diagram Timer/Counter DATA BUS = TCNTn Waveform Generation OCn = 0 Control Logic = 0xFF BOTTOM TOP count clear direction TOVn (Int. Req.) OCn (Int. Req.) Synchronization Unit OCRn TCCRn ASSRn Status Flags clkI/O clkASY Synchronized Status Flags asynchronous Mode Select (ASn) TOSC1 T/C Oscillator TOSC2 Prescaler clkTn clkI/OATmega8A [DATASHEET] 100 8159E–AVR–02/2013 18.2.1 Registers The Timer/Counter (TCNT2) and Output Compare Register (OCR2) are 8-bit registers. Interrupt request (shorten as Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFR). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK). TIFR and TIMSK are not shown in the figure since these registers are shared by other timer units. The Timer/Counter can be clocked internally, via the prescaler, or asynchronously clocked from the TOSC1/2 pins, as detailed later in this section. The asynchronous operation is controlled by the Asynchronous Status Register (ASSR). The Clock Select logic block controls which clock source the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the clock select logic is referred to as the timer clock (clkT2). The double buffered Output Compare Register (OCR2) is compared with the Timer/Counter value at all times. The result of the compare can be used by the waveform generator to generate a PWM or variable frequency output on the Output Compare Pin (OC2). For details, see “Output Compare Unit” on page 101. The Compare Match event will also set the Compare Flag (OCF2) which can be used to generate an Output Compare interrupt request. 18.2.2 Definitions Many register and bit references in this document are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 2. However, when using the register or bit defines in a program, the precise form must be used (i.e., TCNT2 for accessing Timer/Counter2 counter value and so on). The definitions in Table 18-1 are also used extensively throughout the document. 18.3 Timer/Counter Clock Sources The Timer/Counter can be clocked by an internal synchronous or an external asynchronous clock source. The clock source clkT2 is by default equal to the MCU clock, clkI/O. When the AS2 bit in the ASSR Register is written to logic one, the clock source is taken from the Timer/Counter Oscillator connected to TOSC1 and TOSC2. For details on asynchronous operation, see “Asynchronous Operation of the Timer/Counter” on page 109. For details on clock sources and prescaler, see “Timer/Counter0 and Timer/Counter1 Prescalers” on page 71. 18.4 Counter Unit The main part of the 8-bit Timer/Counter is the programmable bi-directional counter unit. Figure 18-2 shows a block diagram of the counter and its surrounding environment. Table 18-1. Definitions BOTTOM The counter reaches the BOTTOM when it becomes zero (0x00). MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be the fixed value 0xFF (MAX) or the value stored in the OCR2 Register. The assignment is dependent on the mode of operation.ATmega8A [DATASHEET] 101 8159E–AVR–02/2013 Figure 18-2. Counter Unit Block Diagram Signal description (internal signals): count Increment or decrement TCNT2 by 1. direction Selects between increment and decrement. clear Clear TCNT2 (set all bits to zero). clkT2 Timer/Counter clock. TOP Signalizes that TCNT2 has reached maximum value. BOTTOM Signalizes that TCNT2 has reached minimum value (zero). Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT2). clkT2 can be generated from an external or internal clock source, selected by the clock select bits (CS22:0). When no clock source is selected (CS22:0 = 0) the timer is stopped. However, the TCNT2 value can be accessed by the CPU, regardless of whether clkT2 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the WGM21 and WGM20 bits located in the Timer/Counter Control Register (TCCR2). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare Output OC2. For more details about advanced counting sequences and waveform generation, see “Modes of Operation” on page 104. The Timer/Counter Overflow (TOV2) Flag is set according to the mode of operation selected by the WGM21:0 bits. TOV2 can be used for generating a CPU interrupt. 18.5 Output Compare Unit The 8-bit comparator continuously compares TCNT2 with the Output Compare Register (OCR2). Whenever TCNT2 equals OCR2, the comparator signals a match. A match will set the Output Compare Flag (OCF2) at the next timer clock cycle. If enabled (OCIE2 = 1), the Output Compare Flag generates an Output Compare interrupt. The OCF2 Flag is automatically cleared when the interrupt is executed. Alternatively, the OCF2 Flag can be cleared by software by writing a logical one to its I/O bit location. The waveform generator uses the match signal to generate an output according to operating mode set by the WGM21:0 bits and Compare Output mode (COM21:0) bits. The max and bottom signals are used by the waveform generator for handling the special cases of the extreme values in some modes of operation (see “Modes of Operation” on page 104). Figure 18-3 shows a block diagram of the Output Compare unit. DATA BUS TCNTn Control Logic count TOVn (Int. Req.) BOTTOM TOP direction clear TOSC1 T/C Oscillator TOSC2 Prescaler clkI/O clk TnATmega8A [DATASHEET] 102 8159E–AVR–02/2013 Figure 18-3. Output Compare Unit, Block Diagram The OCR2 Register is double buffered when using any of the Pulse Width Modulation (PWM) modes. For the normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR2 Compare Register to either top or bottom of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR2 Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR2 Buffer Register, and if double buffering is disabled the CPU will access the OCR2 directly. 18.5.1 Force Output Compare In non-PWM Waveform Generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC2) bit. Forcing Compare Match will not set the OCF2 Flag or reload/clear the timer, but the OC2 pin will be updated as if a real Compare Match had occurred (the COM21:0 bits settings define whether the OC2 pin is set, cleared or toggled). 18.5.2 Compare Match Blocking by TCNT2 Write All CPU write operations to the TCNT2 Register will block any Compare Match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR2 to be initialized to the same value as TCNT2 without triggering an interrupt when the Timer/Counter clock is enabled. 18.5.3 Using the Output Compare Unit Since writing TCNT2 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT2 when using the Output Compare channel, independently of whether the Timer/Counter is running or not. If the value written to TCNT2 equals the OCR2 value, the Compare Match will be OCFn (Int. Req.) = (8-bit Comparator ) OCRn OCxy DATA BUS TCNTn WGMn1:0 Waveform Generator TOP FOCn COMn1:0 BOTTOMATmega8A [DATASHEET] 103 8159E–AVR–02/2013 missed, resulting in incorrect waveform generation. Similarly, do not write the TCNT2 value equal to BOTTOM when the counter is downcounting. The setup of the OC2 should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC2 value is to use the Force Output Compare (FOC2) strobe bit in Normal mode. The OC2 Register keeps its value even when changing between waveform generation modes. Be aware that the COM21:0 bits are not double buffered together with the compare value. Changing the COM21:0 bits will take effect immediately. 18.6 Compare Match Output Unit The Compare Output mode (COM21:0) bits have two functions. The waveform generator uses the COM21:0 bits for defining the Output Compare (OC2) state at the next Compare Match. Also, the COM21:0 bits control the OC2 pin output source. Figure 18-4 shows a simplified schematic of the logic affected by the COM21:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM21:0 bits are shown. When referring to the OC2 state, the reference is for the internal OC2 Register, not the OC2 pin. Figure 18-4. Compare Match Output Unit, Schematic The general I/O port function is overridden by the Output Compare (OC2) from the waveform generator if either of the COM21:0 bits are set. However, the OC2 pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC2 pin (DDR_OC2) must be set as output before the OC2 value is visible on the pin. The port override function is independent of the Waveform Generation mode. PORT DDR D Q D Q OCn OCn Pin D Q Waveform Generator COMn1 COMn0 0 1 DATABUS FOCn clkI/OATmega8A [DATASHEET] 104 8159E–AVR–02/2013 The design of the Output Compare Pin logic allows initialization of the OC2 state before the output is enabled. Note that some COM21:0 bit settings are reserved for certain modes of operation. See “Register Description” on page 112. 18.6.1 Compare Output Mode and Waveform Generation The Waveform Generator uses the COM21:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM21:0 = 0 tells the waveform generator that no action on the OC2 Register is to be performed on the next Compare Match. For compare output actions in the non-PWM modes refer to Table 18-3 on page 112. For fast PWM mode, refer to Table 18-4 on page 113, and for phase correct PWM refer to Table 18-5 on page 113. A change of the COM21:0 bits state will have effect at the first Compare Match after the bits are written. For nonPWM modes, the action can be forced to have immediate effect by using the FOC2 strobe bits. 18.7 Modes of Operation The mode of operation (i.e., the behavior of the Timer/Counter and the Output Compare pins) is defined by the combination of the Waveform Generation mode (WGM21:0) and Compare Output mode (COM21:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM21:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM21:0 bits control whether the output should be set, cleared, or toggled at a Compare Match (see “Compare Match Output Unit” on page 103). For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 108. 18.7.1 Normal Mode The simplest mode of operation is the Normal mode (WGM21:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 8- bit value (TOP = 0xFF) and then restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV2) will be set in the same timer clock cycle as the TCNT2 becomes zero. The TOV2 Flag in this case behaves like a ninth bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV2 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Output Compare unit can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 18.7.2 Clear Timer on Compare Match (CTC) Mode In Clear Timer on Compare or CTC mode (WGM21:0 = 2), the OCR2 Register is used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT2) matches the OCR2. The OCR2 defines the top value for the counter, hence also its resolution. This mode allows greater control of the Compare Match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 18-5. The counter value (TCNT2) increases until a Compare Match occurs between TCNT2 and OCR2, and then counter (TCNT2) is cleared.ATmega8A [DATASHEET] 105 8159E–AVR–02/2013 Figure 18-5. CTC Mode, Timing Diagram An interrupt can be generated each time the counter value reaches the TOP value by using the OCF2 Flag. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR2 is lower than the current value of TCNT2, the counter will miss the Compare Match. The counter will then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the Compare Match can occur. For generating a waveform output in CTC mode, the OC2 output can be set to toggle its logical level on each Compare Match by setting the Compare Output mode bits to toggle mode (COM21:0 = 1). The OC2 value will not be visible on the port pin unless the data direction for the pin is set to output. The waveform generated will have a maximum frequency of fOC2 = fclk_I/O/2 when OCR2 is set to zero (0x00). The waveform frequency is defined by the following equation: The N variable represents the prescaler factor (1, 8, 32, 64, 128, 256, or 1024). As for the Normal mode of operation, the TOV2 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x00. 18.7.3 Fast PWM Mode The fast Pulse Width Modulation or fast PWM mode (WGM21:0 = 3) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM option by its single-slope operation. The counter counts from BOTTOM to MAX then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC2) is cleared on the Compare Match between TCNT2 and OCR2, and set at BOTTOM. In inverting Compare Output mode, the output is set on Compare Match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct PWM mode that uses dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), and therefore reduces total system cost. In fast PWM mode, the counter is incremented until the counter value matches the MAX value. The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 18-6. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2 and TCNT2. TCNTn OCn (Toggle) OCn Interrupt Flag Set Period 1 2 3 4 (COMn1:0 = 1) f OCn f clk_I/O 2   N   1 + OCRn = ----------------------------------------------ATmega8A [DATASHEET] 106 8159E–AVR–02/2013 Figure 18-6. Fast PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches MAX. If the interrupt is enabled, the interrupt handler routine can be used for updating the compare value. In fast PWM mode, the compare unit allows generation of PWM waveforms on the OC2 pin. Setting the COM21:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM21:0 to 3 (see Table 18-4 on page 113). The actual OC2 value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by setting (or clearing) the OC2 Register at the Compare Match between OCR2 and TCNT2, and clearing (or setting) the OC2 Register at the timer clock cycle the counter is cleared (changes from MAX to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescaler factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2 Register represent special cases when generating a PWM waveform output in the fast PWM mode. If the OCR2 is set equal to BOTTOM, the output will be a narrow spike for each MAX+1 timer clock cycle. Setting the OCR2 equal to MAX will result in a constantly high or low output (depending on the polarity of the output set by the COM21:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC2 to toggle its logical level on each Compare Match (COM21:0 = 1). The waveform generated will have a maximum frequency of foc2 = fclk_I/O/2 when OCR2 is set to zero. This feature is similar to the OC2 toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 18.7.4 Phase Correct PWM Mode The phase correct PWM mode (WGM21:0 = 1) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is based on a dual-slope operation. The counter counts repeatedly from BOTTOM to MAX and then from MAX to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC2) is cleared on the Compare Match between TCNT2 and OCR2 while upcounting, and set on the Compare Match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation TCNTn OCRn Update and TOVn Interrupt Flag Set Period 1 2 3 OCn OCn (COMn1:0 = 2) (COMn1:0 = 3) OCRn Interrupt Flag Set 4 5 6 7 f OCnPWM f clk_I/O N  256 = ------------------ATmega8A [DATASHEET] 107 8159E–AVR–02/2013 has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode is fixed to eight bits. In phase correct PWM mode the counter is incremented until the counter value matches MAX. When the counter reaches MAX, it changes the count direction. The TCNT2 value will be equal to MAX for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 18-7. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2 and TCNT2. Figure 18-7. Phase Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches BOTTOM. The Interrupt Flag can be used to generate an interrupt each time the counter reaches the BOTTOM value. In phase correct PWM mode, the compare unit allows generation of PWM waveforms on the OC2 pin. Setting the COM21:0 bits to 2 will produce a non-inverted PWM. An inverted PWM output can be generated by setting the COM21:0 to 3 (see Table 18-5 on page 113). The actual OC2 value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by clearing (or setting) the OC2 Register at the Compare Match between OCR2 and TCNT2 when the counter increments, and setting (or clearing) the OC2 Register at Compare Match between OCR2 and TCNT2 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescaler factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2 Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR2 is set equal to BOTTOM, the output will be continuously low and if set equal to MAX the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. TOVn Interrupt Flag Set OCn Interrupt Flag Set 1 2 3 TCNTn Period OCn OCn (COMn1:0 = 2) (COMn1:0 = 3) OCRn Update f OCnPCPWM f clk_I/O N  510 = ------------------ATmega8A [DATASHEET] 108 8159E–AVR–02/2013 At the very start of period 2 in Figure 18-7 OCn has a transition from high to low even though there is no Compare Match. The point of this transition is to guarantee symmetry around BOTTOM. There are two cases that give a transition without Compare Match: • OCR2A changes its value from MAX, like in Figure 18-7. When the OCR2A value is MAX the OCn pin value is the same as the result of a down-counting Compare Match. To ensure symmetry around BOTTOM the OCn value at MAX must correspond to the result of an up-counting Compare Match. • The timer starts counting from a value higher than the one in OCR2A, and for that reason misses the Compare Match and hence the OCn change that would have happened on the way up. 18.8 Timer/Counter Timing Diagrams The following figures show the Timer/Counter in Synchronous mode, and the timer clock (clkT2) is therefore shown as a clock enable signal. In Asynchronous mode, clkI/O should be replaced by the Timer/Counter Oscillator clock. The figures include information on when Interrupt Flags are set. Figure 18-8 contains timing data for basic Timer/Counter operation. The figure shows the count sequence close to the MAX value in all modes other than phase correct PWM mode. Figure 18-8. Timer/Counter Timing Diagram, no Prescaling Figure 18-9 shows the same timing data, but with the prescaler enabled. Figure 18-9. Timer/Counter Timing Diagram, with Prescaler (fclk_I/O/8) Figure 18-10 shows the setting of OCF2 in all modes except CTC mode. clkTn (clkI/O/1) TOVn clkI/O TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 TOVn TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8)ATmega8A [DATASHEET] 109 8159E–AVR–02/2013 Figure 18-10. Timer/Counter Timing Diagram, Setting of OCF2, with Prescaler (fclk_I/O/8) Figure 18-11 shows the setting of OCF2 and the clearing of TCNT2 in CTC mode. Figure 18-11. Timer/Counter Timing Diagram, Clear Timer on Compare Match Mode, with Prescaler (fclk_I/O/8) 18.9 Asynchronous Operation of the Timer/Counter 18.9.1 Asynchronous Operation of Timer/Counter2 When Timer/Counter2 operates asynchronously, some considerations must be taken. • Warning: When switching between asynchronous and synchronous clocking of Timer/Counter2, the Timer Registers TCNT2, OCR2, and TCCR2 might be corrupted. A safe procedure for switching clock source is: 1. Disable the Timer/Counter2 interrupts by clearing OCIE2 and TOIE2. 2. Select clock source by setting AS2 as appropriate. 3. Write new values to TCNT2, OCR2, and TCCR2. 4. To switch to asynchronous operation: Wait for TCN2UB, OCR2UB, and TCR2UB. 5. Clear the Timer/Counter2 Interrupt Flags. 6. Enable interrupts, if needed. OCFn OCRn TCNTn OCRn Value OCRn - 1 OCRn OCRn + 1 OCRn + 2 clkI/O clkTn (clkI/O/8) OCFn OCRn TCNTn (CTC) TOP TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8)ATmega8A [DATASHEET] 110 8159E–AVR–02/2013 • The Oscillator is optimized for use with a 32.768 kHz watch crystal. Applying an external clock to the TOSC1 pin may result in incorrect Timer/Counter2 operation. The CPU main clock frequency must be more than four times the Oscillator frequency. • When writing to one of the registers TCNT2, OCR2, or TCCR2, the value is transferred to a temporary register, and latched after two positive edges on TOSC1. The user should not write a new value before the contents of the temporary register have been transferred to its destination. Each of the three mentioned registers have their individual temporary register, which means that e.g. writing to TCNT2 does not disturb an OCR2 write in progress. To detect that a transfer to the destination register has taken place, the Asynchronous Status Register – ASSR has been implemented. • When entering Power-save mode after having written to TCNT2, OCR2, or TCCR2, the user must wait until the written register has been updated if Timer/Counter2 is used to wake up the device. Otherwise, the MCU will enter sleep mode before the changes are effective. This is particularly important if the Output Compare2 interrupt is used to wake up the device, since the Output Compare function is disabled during writing to OCR2 or TCNT2. If the write cycle is not finished, and the MCU enters sleep mode before the OCR2UB bit returns to zero, the device will never receive a Compare Match interrupt, and the MCU will not wake up. • If Timer/Counter2 is used to wake the device up from Power-save mode, precautions must be taken if the user wants to re-enter one of these modes: The interrupt logic needs one TOSC1 cycle to be reset. If the time between wake-up and re-entering sleep mode is less than one TOSC1 cycle, the interrupt will not occur, and the device will fail to wake up. If the user is in doubt whether the time before re-entering Power-save or Extended Standby mode is sufficient, the following algorithm can be used to ensure that one TOSC1 cycle has elapsed: 1. Write a value to TCCR2, TCNT2, or OCR2. 2. Wait until the corresponding Update Busy Flag in ASSR returns to zero. 3. Enter Power-save or Extended Standby mode. • When the asynchronous operation is selected, the 32.768kHz Oscillator for Timer/Counter2 is always running, except in Power-down and Standby modes. After a Power-up Reset or Wake-up from Power-down or Standby mode, the user should be aware of the fact that this Oscillator might take as long as one second to stabilize. The user is advised to wait for at least one second before using Timer/Counter2 after Power-up or Wake-up from Power-down or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after a wake-up from Power-down or Standby mode due to unstable clock signal upon start-up, no matter whether the Oscillator is in use or a clock signal is applied to the TOSC1 pin. • Description of wake up from Power-save or Extended Standby mode when the timer is clocked asynchronously: When the interrupt condition is met, the wake up process is started on the following cycle of the timer clock, that is, the timer is always advanced by at least one before the processor can read the counter value. After wake-up, the MCU is halted for four cycles, it executes the interrupt routine, and resumes execution from the instruction following SLEEP. • Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect result. Since TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be done through a register synchronized to the internal I/O clock domain. Synchronization takes place for every rising TOSC1 edge. When waking up from Power-save mode, and the I/O clock (clkI/O) again becomes active, TCNT2 will read as the previous value (before entering sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after waking up from Power-save mode is essentially unpredictable, as it depends on the wake-up time. The recommended procedure for reading TCNT2 is thus as follows: 1. Write any value to either of the registers OCR2 or TCCR2. 2. Wait for the corresponding Update Busy Flag to be cleared. 3. Read TCNT2. • During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous timer takes three processor cycles plus one timer cycle. The timer is therefore advanced by at least one before the ATmega8A [DATASHEET] 111 8159E–AVR–02/2013 processor can read the timer value causing the setting of the Interrupt Flag. The Output Compare Pin is changed on the timer clock and is not synchronized to the processor clock. 18.10 Timer/Counter Prescaler Figure 18-12. Prescaler for Timer/Counter2 The clock source for Timer/Counter2 is named clkT2S. clkT2S is by default connected to the main system I/O clock clkI/O. By setting the AS2 bit in ASSR, Timer/Counter2 is asynchronously clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real Time Counter (RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from Port B. A crystal can then be connected between the TOSC1 and TOSC2 pins to serve as an independent clock source for Timer/Counter2. The Oscillator is optimized for use with a 32.768kHz crystal. Applying an external clock source to TOSC1 is not recommended. For Timer/Counter2, the possible prescaled selections are: clkT2S/8, clkT2S/32, clkT2S/64, clkT2S/128, clkT2S/256, and clkT2S/1024. Additionally, clkT2S as well as 0 (stop) may be selected. Setting the PSR2 bit in SFIOR resets the prescaler. This allows the user to operate with a predictable prescaler. 10-BIT T/C PRESCALER TIMER/COUNTER2 CLOCK SOURCE clkI/O clkT2S TOSC1 AS2 CS20 CS21 CS22 clkT2S/8 clkT2S/64 clkT2S/128 clkT2S/1024 clkT2S/256 clkT2S/32 0 PSR2 Clear clkT2ATmega8A [DATASHEET] 112 8159E–AVR–02/2013 18.11 Register Description 18.11.1 TCCR2 – Timer/Counter Control Register • Bit 7 – FOC2: Force Output Compare The FOC2 bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2 is written when operating in PWM mode. When writing a logical one to the FOC2 bit, an immediate Compare Match is forced on the waveform generation unit. The OC2 output is changed according to its COM21:0 bits setting. Note that the FOC2 bit is implemented as a strobe. Therefore it is the value present in the COM21:0 bits that determines the effect of the forced compare. A FOC2 strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2 as TOP. The FOC2 bit is always read as zero. • Bit 6,3 – WGM21:0: Waveform Generation Mode These bits control the counting sequence of the counter, the source for the maximum (TOP) counter value, and what type of waveform generation to be used. Modes of operation supported by the Timer/Counter unit are: Normal mode, Clear Timer on Compare Match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes. See Table 18-2 and “Modes of Operation” on page 104. Note: 1. The CTC2 and PWM2 bit definition names are now obsolete. Use the WGM21:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer. • Bit 5:4 – COM21:0: Compare Match Output Mode These bits control the Output Compare Pin (OC2) behavior. If one or both of the COM21:0 bits are set, the OC2 output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to OC2 pin must be set in order to enable the output driver. When OC2 is connected to the pin, the function of the COM21:0 bits depends on the WGM21:0 bit setting. Table 18-3 shows the COM21:0 bit functionality when the WGM21:0 bits are set to a normal or CTC mode (non-PWM). Bit 7 6 5 4 3 2 1 0 FOC2 WGM20 COM21 COM20 WGM21 CS22 CS21 CS20 TCCR2 Read/Write W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 18-2. Waveform Generation Mode Bit Description Mode WGM21 (CTC2) WGM20 (PWM2) Timer/Counter Mode of Operation(1) TOP Update of OCR2 TOV2 Flag Set 0 0 0 Normal 0xFF Immediate MAX 1 0 1 PWM, Phase Correct 0xFF TOP BOTTOM 2 1 0 CTC OCR2 Immediate MAX 3 1 1 Fast PWM 0xFF BOTTOM MAX Table 18-3. Compare Output Mode, Non-PWM Mode COM21 COM20 Description 0 0 Normal port operation, OC2 disconnected. 0 1 Toggle OC2 on Compare Match 1 0 Clear OC2 on Compare Match 1 1 Set OC2 on Compare MatchATmega8A [DATASHEET] 113 8159E–AVR–02/2013 Table 18-4 shows the COM21:0 bit functionality when the WGM21:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR2 equals TOP and COM21 is set. In this case, the Compare Match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on page 105 for more details. Table 18-5 shows the COM21:0 bit functionality when the WGM21:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2 equals TOP and COM21 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase Correct PWM Mode” on page 106 for more details. • Bit 2:0 – CS22:0: Clock Select The three clock select bits select the clock source to be used by the Timer/Counter, see Table 18-6. 18.11.2 TCNT2 – Timer/Counter Register Table 18-4. Compare Output Mode, Fast PWM Mode(1) COM21 COM20 Description 0 0 Normal port operation, OC2 disconnected. 0 1 Reserved 1 0 Clear OC2 on Compare Match, set OC2 at BOTTOM, (non-inverting mode) 1 1 Set OC2 on Compare Match, clear OC2 at BOTTOM, (inverting mode) Table 18-5. Compare Output Mode, Phase Correct PWM Mode(1) COM21 COM20 Description 0 0 Normal port operation, OC2 disconnected. 0 1 Reserved 1 0 Clear OC2 on Compare Match when up-counting. Set OC2 on Compare Match when downcounting. 1 1 Set OC2 on Compare Match when up-counting. Clear OC2 on Compare Match when downcounting. Table 18-6. Clock Select Bit Description CS22 CS21 CS20 Description 0 0 0 No clock source (Timer/Counter stopped). 0 0 1 clkT2S/(No prescaling) 0 1 0 clkT2S/8 (From prescaler) 0 1 1 clkT2S/32 (From prescaler) 1 0 0 clkT2S/64 (From prescaler) 1 0 1 clkT2S/128 (From prescaler) 1 1 0 clkT2S/256 (From prescaler) 1 1 1 clkT2S/1024 (From prescaler) Bit 7 6 5 4 3 2 1 0 TCNT2[7:0] TCNT2 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 114 8159E–AVR–02/2013 The Timer/Counter Register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the Compare Match on the following timer clock. Modifying the counter (TCNT2) while the counter is running, introduces a risk of missing a Compare Match between TCNT2 and the OCR2 Register. 18.11.3 OCR2 – Output Compare Register The Output Compare Register contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2 pin. 18.11.4 ASSR – Asynchronous Status Register • Bit 3 – AS2: Asynchronous Timer/Counter2 When AS2 is written to zero, Timer/Counter 2 is clocked from the I/O clock, clkI/O. When AS2 is written to one, Timer/Counter 2 is clocked from a crystal Oscillator connected to the Timer Oscillator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of TCNT2, OCR2, and TCCR2 might be corrupted. • Bit 2 – TCN2UB: Timer/Counter2 Update Busy When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set. When TCNT2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value. • Bit 1 – OCR2UB: Output Compare Register2 Update Busy When Timer/Counter2 operates asynchronously and OCR2 is written, this bit becomes set. When OCR2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2 is ready to be updated with a new value. • Bit 0 – TCR2UB: Timer/Counter Control Register2 Update Busy When Timer/Counter2 operates asynchronously and TCCR2 is written, this bit becomes set. When TCCR2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2 is ready to be updated with a new value. If a write is performed to any of the three Timer/Counter2 Registers while its update busy flag is set, the updated value might get corrupted and cause an unintentional interrupt to occur. The mechanisms for reading TCNT2, OCR2, and TCCR2 are different. When reading TCNT2, the actual timer value is read. When reading OCR2 or TCCR2, the value in the temporary storage register is read. Bit 7 6 5 4 3 2 1 0 OCR2[7:0] OCR2 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – – – AS2 TCN2UB OCR2UB TCR2UB ASSR Read/Write R R R R R/W R R R Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 115 8159E–AVR–02/2013 18.11.5 TIMSK – Timer/Counter Interrupt Mask Register • Bit 7 – OCIE2: Timer/Counter2 Output Compare Match Interrupt Enable When the OCIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match interrupt is enabled. The corresponding interrupt is executed if a Compare Match in Timer/Counter2 occurs (i.e., when the OCF2 bit is set in the Timer/Counter Interrupt Flag Register – TIFR). • Bit 6 – TOIE2: Timer/Counter2 Overflow Interrupt Enable When the TOIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter2 occurs (i.e., when the TOV2 bit is set in the Timer/Counter Interrupt Flag Register – TIFR). 18.11.6 TIFR – Timer/Counter Interrupt Flag Register • Bit 7 – OCF2: Output Compare Flag 2 The OCF2 bit is set (one) when a Compare Match occurs between the Timer/Counter2 and the data in OCR2 – Output Compare Register2. OCF2 is cleared by hardware when executing the corresponding interrupt Handling Vector. Alternatively, OCF2 is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2 (Timer/Counter2 Compare Match Interrupt Enable), and OCF2 are set (one), the Timer/Counter2 Compare Match Interrupt is executed. • Bit 6 – TOV2: Timer/Counter2 Overflow Flag The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when executing the corresponding interrupt Handling Vector. Alternatively, TOV2 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE2 (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter2 changes counting direction at 0x00. 18.11.7 SFIOR – Special Function IO Register • Bit 1 – PSR2: Prescaler Reset Timer/Counter2 When this bit is written to one, the Timer/Counter2 prescaler will be reset. The bit will be cleared by hardware after the operation is performed. Writing a zero to this bit will have no effect. This bit will always be read as zero if Timer/Counter2 is clocked by the internal CPU clock. If this bit is written when Timer/Counter2 is operating in Asynchronous mode, the bit will remain one until the prescaler has been reset. Bit 7 6 5 4 3 2 1 0 OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 TIMSK Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 TIFR Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – – – ACME PUD PSR2 PSR10 SFIOR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATmega8A [DATASHEET] 116 8159E–AVR–02/2013 19. Serial Peripheral Interface – SPI 19.1 Features • Full-duplex, Three-wire Synchronous Data Transfer • Master or Slave Operation • LSB First or MSB First Data Transfer • Seven Programmable Bit Rates • End of Transmission Interrupt Flag • Write Collision Flag Protection • Wake-up from Idle Mode • Double Speed (CK/2) Master SPI Mode 19.2 Overview The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the ATmega8A and peripheral devices or between several AVR devices. Figure 19-1. SPI Block Diagram(1) Note: 1. Refer to “Pin Configurations” on page 2, and Table 13-2 on page 56 for SPI pin placement. The interconnection between Master and Slave CPUs with SPI is shown in Figure 19-2. The system consists of two Shift Registers, and a Master clock generator. The SPI Master initiates the communication cycle when pulling low SPI2X SPI2X DIVIDER /2/4/8/16/32/64/128ATmega8A [DATASHEET] 117 8159E–AVR–02/2013 the Slave Select SS pin of the desired Slave. Master and Slave prepare the data to be sent in their respective Shift Registers, and the Master generates the required clock pulses on the SCK line to interchange data. Data is always shifted from Master to Slave on the Master Out – Slave In, MOSI, line, and from Slave to Master on the Master In – Slave Out, MISO, line. After each data packet, the Master will synchronize the Slave by pulling high the Slave Select, SS, line. When configured as a Master, the SPI interface has no automatic control of the SS line. This must be handled by user software before communication can start. When this is done, writing a byte to the SPI Data Register starts the SPI clock generator, and the hardware shifts the eight bits into the Slave. After shifting one byte, the SPI clock generator stops, setting the end of Transmission Flag (SPIF). If the SPI interrupt enable bit (SPIE) in the SPCR Register is set, an interrupt is requested. The Master may continue to shift the next byte by writing it into SPDR, or signal the end of packet by pulling high the Slave Select, SS line. The last incoming byte will be kept in the Buffer Register for later use. When configured as a Slave, the SPI interface will remain sleeping with MISO tri-stated as long as the SS pin is driven high. In this state, software may update the contents of the SPI Data Register, SPDR, but the data will not be shifted out by incoming clock pulses on the SCK pin until the SS pin is driven low. As one byte has been completely shifted, the end of Transmission Flag, SPIF is set. If the SPI interrupt enable bit, SPIE, in the SPCR Register is set, an interrupt is requested. The Slave may continue to place new data to be sent into SPDR before reading the incoming data. The last incoming byte will be kept in the Buffer Register for later use. Figure 19-2. SPI Master-Slave Interconnection The system is single buffered in the transmit direction and double buffered in the receive direction. This means that bytes to be transmitted cannot be written to the SPI Data Register before the entire shift cycle is completed. When receiving data, however, a received character must be read from the SPI Data Register before the next character has been completely shifted in. Otherwise, the first byte is lost. In SPI Slave mode, the control logic will sample the incoming signal of the SCK pin. To ensure correct sampling of the clock signal, the minimum low and high periods should be: Low period: longer than 2 CPU clock cycles High period: longer than 2 CPU clock cycles. When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden according to Table 19-1. For more details on automatic port overrides, refer to “Alternate Port Functions” on page 54. MSB MASTER LSB 8 BIT SHIFT REGISTER MSB SLAVE LSB 8 BIT SHIFT REGISTER MISO MOSI SPI CLOCK GENERATOR SCK SS MISO MOSI SCK SS VCC SHIFT ENABLEATmega8A [DATASHEET] 118 8159E–AVR–02/2013 Note: 1. See “Port B Pins Alternate Functions” on page 56 for a detailed description of how to define the direction of the user defined SPI pins. The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. E.g. if MOSI is placed on pin PB5, replace DD_MOSI with DDB5 and DDR_SPI with DDRB. Table 19-1. SPI Pin Overrides(1) Pin Direction, Master SPI Direction, Slave SPI MOSI User Defined Input MISO Input User Defined SCK User Defined Input SS User Defined InputATmega8A [DATASHEET] 119 8159E–AVR–02/2013 Note: 1. See “About Code Examples” on page 6. Assembly Code Example(1) SPI_MasterInit: ; Set MOSI and SCK output, all others input ldi r17,(1<>8); UBRRL = (unsigned char)ubrr; /* Enable receiver and transmitter */ UCSRB = (1<> 1) & 0x01; return ((resh << 8) | resl); }ATmega8A [DATASHEET] 137 8159E–AVR–02/2013 20.6.9 Receive Compete Flag and Interrupt The USART Receiver has one flag that indicates the Receiver state. The Receive Complete (RXC) Flag indicates if there are unread data present in the receive buffer. This flag is one when unread data exist in the receive buffer, and zero when the receive buffer is empty (i.e., does not contain any unread data). If the Receiver is disabled (RXEN = 0), the receive buffer will be flushed and consequently the RXC bit will become zero. When the Receive Complete Interrupt Enable (RXCIE) in UCSRB is set, the USART Receive Complete Interrupt will be executed as long as the RXC Flag is set (provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDR in order to clear the RXC Flag, otherwise a new interrupt will occur once the interrupt routine terminates. 20.6.10 Receiver Error Flags The USART Receiver has three error flags: Frame Error (FE), Data OverRun (DOR) and Parity Error (PE). All can be accessed by reading UCSRA. Common for the error flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the error flags, the UCSRA must be read before the receive buffer (UDR), since reading the UDR I/O location changes the buffer read location. Another equality for the error flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRA is written for upward compatibility of future USART implementations. None of the error flags can generate interrupts. The Frame Error (FE) Flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FE Flag is zero when the stop bit was correctly read (as one), and the FE Flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FE Flag is not affected by the setting of the USBS bit in UCSRC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRA. The Data OverRun (DOR) Flag indicates data loss due to a Receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DOR Flag is set there was one or more serial frame lost between the frame last read from UDR, and the next frame read from UDR. For compatibility with future devices, always write this bit to zero when writing to UCSRA. The DOR Flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (PE) Flag indicates that the next frame in the receive buffer had a parity error when received. If parity check is not enabled the PE bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRA. For more details see “Parity Bit Calculation” on page 130 and “Parity Checker” on page 137. 20.6.11 Parity Checker The Parity Checker is active when the high USART Parity mode (UPM1) bit is set. Type of parity check to be performed (odd or even) is selected by the UPM0 bit. When enabled, the Parity Checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error (PE) Flag can then be read by software to check if the frame had a parity error. The PE bit is set if the next character that can be read from the receive buffer had a parity error when received and the parity checking was enabled at that point (UPM1 = 1). This bit is valid until the receive buffer (UDR) is read. 20.6.12 Disabling the Receiver In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing receptions will therefore be lost. When disabled (i.e., the RXEN is set to zero) the Receiver will no longer override the normal functionATmega8A [DATASHEET] 138 8159E–AVR–02/2013 of the RxD port pin. The Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in the buffer will be lost. 20.6.13 Flushing the Receive Buffer The Receiver buffer FIFO will be flushed when the Receiver is disabled (i.e., the buffer will be emptied of its contents). Unread data will be lost. If the buffer has to be flushed during normal operation, due to for instance an error condition, read the UDR I/O location until the RXC Flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See “About Code Examples” on page 6. 20.7 Asynchronous Data Reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxD pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the Receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. 20.7.1 Asynchronous Clock Recovery The clock recovery logic synchronizes internal clock to the incoming serial frames. Figure 20-5 illustrates the sampling process of the start bit of an incoming frame. The sample rate is 16 times the baud rate for Normal mode, and eight times the baud rate for Double Speed mode. The horizontal arrows illustrate the synchronization variation due to the sampling process. Note the larger time variation when using the Double Speed mode (U2X = 1) of operation. Samples denoted zero are samples done when the RxD line is idle (i.e., no communication activity). Figure 20-5. Start Bit Sampling When the clock recovery logic detects a high (idle) to low (start) transition on the RxD line, the start bit detection sequence is initiated. Let sample 1 denote the first zero-sample as shown in the figure. The clock recovery logic Assembly Code Example(1) USART_Flush: sbis UCSRA, RXC ret in r16, UDR rjmp USART_Flush C Code Example(1) void USART_Flush( void ) { unsigned char dummy; while ( UCSRA & (1< 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck  12MHz High: > 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck  12MHz 25.9.1 Serial Programming Algorithm When writing serial data to the ATmega8A, data is clocked on the rising edge of SCK. When reading data from the ATmega8A, data is clocked on the falling edge of SCK. See Figure 25-8 for timing details. Table 25-14. Pin Mapping Serial Programming Symbol Pins I/O Description MOSI PB3 I Serial data in MISO PB4 O Serial data out SCK PB5 I Serial clock VCC GND XTAL1 SCK MISO MOSI RESET PB3 PB4 PB5 +2.7 - 5.5V AVCC +2.7 - 5.5V (2)ATmega8A [DATASHEET] 221 8159E–AVR–02/2013 To program and verify the ATmega8A in the Serial Programming mode, the following sequence is recommended (See four byte instruction formats in Table 25-16): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to “0”. In some systems, the programmer can not guarantee that SCK is held low during Power-up. In this case, RESET must be given a positive pulse of at least two CPU clock cycles duration after SCK has been set to “0”. 2. Wait for at least 20 ms and enable Serial Programming by sending the Programming Enable serial instruction to pin MOSI. 3. The Serial Programming instructions will not work if the communication is out of synchronization. When in sync. the second byte (0x53), will echo back when issuing the third byte of the Programming Enable instruction. Whether the echo is correct or not, all four bytes of the instruction must be transmitted. If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command. 4. The Flash is programmed one page at a time. The page size is found in Table 25-5 on page 210. The memory page is loaded one byte at a time by supplying the 5LSB of the address and data together with the Load Program memory Page instruction. To ensure correct loading of the page, the data Low byte must be loaded before data High byte is applied for a given address. The Program memory Page is stored by loading the Write Program memory Page instruction with the 7 MSB of the address. If polling is not used, the user must wait at least tWD_FLASH before issuing the next page. (See Table 25-15). 5. Note: If other commands than polling (read) are applied before any write operation (FLASH, EEPROM, Lock Bits, Fuses) is completed, it may result in incorrect programming. 6. The EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. If polling is not used, the user must wait at least tWD_EEPROM before issuing the next byte. (See Table 25-15 on page 222). In a chip erased device, no 0xFFs in the data file(s) need to be programmed. 7. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO. 8. At the end of the programming session, RESET can be set high to commence normal operation. 9. Power-off sequence (if needed): Set RESET to “1”. Turn VCC power off 25.9.2 Data Polling Flash When a page is being programmed into the Flash, reading an address location within the page being programmed will give the value 0xFF. At the time the device is ready for a new page, the programmed value will read correctly. This is used to determine when the next page can be written. Note that the entire page is written simultaneously and any address within the page can be used for polling. Data polling of the Flash will not work for the value 0xFF, so when programming this value, the user will have to wait for at least tWD_FLASH before programming the next page. As a chip-erased device contains 0xFF in all locations, programming of addresses that are meant to contain 0xFF, can be skipped. See Table 97 for tWD_FLASH value. 25.9.3 Data Polling EEPROM When a new byte has been written and is being programmed into EEPROM, reading the address location being programmed will give the value 0xFF. At the time the device is ready for a new byte, the programmed value will read correctly. This is used to determine when the next byte can be written. This will not work for the value 0xFF, but the user should have the following in mind: As a chip-erased device contains 0xFF in all locations, programming of addresses that are meant to contain 0xFF, can be skipped. This does not apply if the EEPROM is Re-ATmega8A [DATASHEET] 222 8159E–AVR–02/2013 programmed without chip-erasing the device. In this case, data polling cannot be used for the value 0xFF, and the user will have to wait at least tWD_EEPROM before programming the next byte. See Table 25-15 for tWD_EEPROM value. Figure 25-8. Serial Programming Waveforms Table 25-15. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location Symbol Minimum Wait Delay tWD_FUSE 4.5 ms tWD_FLASH 4.5 ms tWD_EEPROM 9.0 ms tWD_ERASE 9.0 ms MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUTATmega8A [DATASHEET] 223 8159E–AVR–02/2013 Note: a = address high bits b = address low bits H = 0 – Low byte, 1 – High byte o = data out i = data in x = don’t care Table 25-16. Serial Programming Instruction Set Instruction Instruction Format Byte 1 Byte 2 Byte 3 Byte4 Operation Programming Enable 1010 1100 0101 0011 xxxx xxxx xxxx xxxx Enable Serial Programming after RESET goes low. Chip Erase 1010 1100 100x xxxx xxxx xxxx xxxx xxxx Chip Erase EEPROM and Flash. Read Program Memory 0010 H000 0000 aaaa bbbb bbbb oooo oooo Read H (high or low) data o from Program memory at word address a:b. Load Program Memory Page 0100 H000 0000 xxxx xxxb bbbb iiii iiii Write H (high or low) data i to Program memory page at word address b. Data Low byte must be loaded before Data High byte is applied within the same address. Write Program Memory Page 0100 1100 0000 aaaa bbbx xxxx xxxx xxxx Write Program memory Page at address a:b. Read EEPROM Memory 1010 0000 00xx xxxa bbbb bbbb oooo oooo Read data o from EEPROM memory at address a:b. Write EEPROM Memory 1100 0000 00xx xxxa bbbb bbbb iiii iiii Write data i to EEPROM memory at address a:b. Read Lock Bits 0101 1000 0000 0000 xxxx xxxx xxoo oooo Read Lock Bits. “0” = programmed, “1” = unprogrammed. See Table 25-1 on page 207 for details. Write Lock Bits 1010 1100 111x xxxx xxxx xxxx 11ii iiii Write Lock Bits. Set bits = “0” to program Lock Bits. See Table 25- 1 on page 207 for details. Read Signature Byte 0011 0000 00xx xxxx xxxx xxbb oooo oooo Read Signature Byte o at address b. Write Fuse Bits 1010 1100 1010 0000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. See Table 25-4 on page 209 for details. Write Fuse High Bits 1010 1100 1010 1000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. See Table 25-3 on page 208 for details. Read Fuse Bits 0101 0000 0000 0000 xxxx xxxx oooo oooo Read Fuse Bits. “0” = programmed, “1” = unprogrammed. See Table 25-4 on page 209 for details. Read Fuse High Bits 0101 1000 0000 1000 xxxx xxxx oooo oooo Read Fuse high bits. “0” = programmed, “1” = unprogrammed. See Table 25-3 on page 208 for details. Read Calibration Byte 0011 1000 00xx xxxx 0000 00bb oooo oooo Read Calibration ByteATmega8A [DATASHEET] 224 8159E–AVR–02/2013 25.9.4 SPI Serial Programming Characteristics For characteristics of the SPI module, see “SPI Timing Characteristics” on page 230.ATmega8A [DATASHEET] 225 8159E–AVR–02/2013 26. Electrical Characteristics – TA = -40°C to 85°C Note: Typical values contained in this datasheet are based on simulations and characterization of other AVR microcontrollers manufactured on the same process technology. Min and Max values will be available after the device is characterized. 26.2 DC Characteristics 26.1 Absolute Maximum Ratings* Operating Temperature.................................. -55C to +125C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ................................................ 40.0mA DC Current VCC and GND Pins................................. 300.0mA TA = -40C to 85C, VCC = 2.7V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min Typ Max Units VIL Input Low Voltage except XTAL1 and RESET pins VCC = 2.7V - 5.5V -0.5 0.2 VCC(1) V VIH Input High Voltage except XTAL1 and RESET pins VCC = 2.7V - 5.5V 0.6 VCC(2) VCC + 0.5 V VIL1 Input Low Voltage XTAL1 pin VCC = 2.7V - 5.5V -0.5 0.1 VCC(1) V VIH1 Input High Voltage XTAL 1 pin VCC = 2.7V - 5.5V 0.8 VCC(2) VCC + 0.5 V VIL2 Input Low Voltage RESET pin VCC = 2.7V - 5.5V -0.5 0.2 VCC V VIH2 Input High Voltage RESET pin VCC = 2.7V - 5.5V 0.9 VCC(2) VCC + 0.5 V VIL3 Input Low Voltage RESET pin as I/O VCC = 2.7V - 5.5V -0.5 0.2 VCC V VIH3 Input High Voltage RESET pin as I/O VCC = 2.7V - 5.5V 0.6 VCC(2) 0.7 VCC(2) VCC + 0.5 V VOL Output Low Voltage(3) (Ports B,C,D) I OL = 20mA, VCC = 5V IOL = 10mA, VCC = 3V 0.9 0.6 V V VOH Output High Voltage(4) (Ports B,C,D) I OH = -20mA, VCC = 5V IOH = -10mA, VCC = 3V 4.2 2.2 V V IIL Input Leakage Current I/O Pin Vcc = 5.5V, pin low (absolute value) 1 µA IIH Input Leakage Current I/O Pin Vcc = 5.5V, pin high (absolute value) 1 µAATmega8A [DATASHEET] 226 8159E–AVR–02/2013 Notes: 1. “Max” means the highest value where the pin is guaranteed to be read as low 2. “Min” means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP, TQFP, and QFN/MLF Package: 1] The sum of all IOL, for all ports, should not exceed 300mA. 2] The sum of all IOL, for ports C0 - C5 should not exceed 100mA. 3] The sum of all IOL, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 200mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP, TQFP, and QFN/MLF Package: 1] The sum of all IOH, for all ports, should not exceed 300mA. 2] The sum of all IOH, for port C0 - C5, should not exceed 100mA. 3] The sum of all IOH, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 200mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 5. Minimum VCC for Power-down is 2.5V. RRST Reset Pull-up Resistor 30 80 k Rpu I/O Pin Pull-up Resistor 20 50 k I CC Power Supply Current Active 4MHz, VCC = 3V 2 5 mA Active 8MHz, VCC = 5V 6 15 mA Idle 4MHz, VCC = 3V 0.5 2 mA Idle 8MHz, VCC = 5V 2.2 7 mA Power-down mode(5) WDT enabled, VCC = 3V <10 28 µA WDT disabled, VCC = 3V <1 3 µA VACIO Analog Comparator Input Offset Voltage VCC = 5V Vin = VCC/2 40 mV IACLK Analog Comparator Input Leakage Current VCC = 5V Vin = VCC/2 -50 50 nA tACPD Analog Comparator Propagation Delay VCC = 2.7V VCC = 5.0V 750 500 ns TA = -40C to 85C, VCC = 2.7V to 5.5V (unless otherwise noted) (Continued) Symbol Parameter Condition Min Typ Max UnitsATmega8A [DATASHEET] 227 8159E–AVR–02/2013 26.3 Speed Grades Figure 26-1. Maximum Frequency vs. Vcc 26.4 Clock Characteristics 26.4.1 External Clock Drive Waveforms Figure 26-2. External Clock Drive Waveforms 26.4.2 External Clock Drive 2.7V 4.5V 5.5V Safe Operating Area 16 MHz 8 MHz VIL1 VIH1 Table 26-1. External Clock Drive Symbol Parameter VCC = 2.7V to 5.5V VCC = 4.5V to 5.5V Min Max Min Max Units 1/tCLCL Oscillator Frequency 0 8 0 16 MHz tCLCL Clock Period 125 62.5 ns tCHCX High Time 50 25 ns tCLCX Low Time 50 25 ns tCLCH Rise Time 1.6 0.5 s tCHCL Fall Time 1.6 0.5 s tCLCL Change in period from one clock cycle to the next 2 2%ATmega8A [DATASHEET] 228 8159E–AVR–02/2013 Notes: 1. R should be in the range 3 k - 100 k, and C should be at least 20 pF. The C values given in the table includes pin capacitance. This will vary with package type. 2. The frequency will vary with package type and board layout. 26.5 System and Reset Characteristics Notes: 1. The Power-on Reset will not work unless the supply voltage has been below VPOT (falling). 2. VBOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is tested down to VCC = VBOT during the production test. This guarantees that a Brown-out Reset will occur before VCC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. The test is performed using BODLEVEL = 1 and BODLEVEL = 0 for ATmega8A. Table 26-2. External RC Oscillator, Typical Frequencies R [k] (1) C [pF] f(2) 33 22 650kHz 10 22 2.0MHz Table 26-3. Reset, Brown-out and Internal Voltage Reference Characteristics Symbol Parameter Condition Min Typ Max Units VPOT Power-on Reset Threshold Voltage (rising)(1) 1.4 2.3 V Power-on Reset Threshold Voltage (falling) 1.3 2.3 V VRST RESET Pin Threshold Voltage 0.2 0.9 VCC tRST Minimum pulse width on RESET Pin 1.5 µs VBOT Brown-out Reset Threshold Voltage(2) BODLEVEL = 1 2.40 2.60 2.90 V BODLEVEL = 0 3.70 4.00 4.50 tBOD Minimum low voltage period for Brownout Detection BODLEVEL = 1 2 µs BODLEVEL = 0 2 µs VHYST Brown-out Detector hysteresis 130 mV VBG Bandgap reference voltage 1.15 1.23 1.35 V tBG Bandgap reference start-up time 40 70 µs IBG Bandgap reference current consumption 10 µsATmega8A [DATASHEET] 229 8159E–AVR–02/2013 26.6 Two-wire Serial Interface Characteristics Table 26-4 describes the requirements for devices connected to the Two-wire Serial Bus. The ATmega8A Two-wire Serial Interface meets or exceeds these requirements under the noted conditions. Timing symbols refer to Figure 26-3. Notes: 1. In ATmega8A, this parameter is characterized and not 100% tested. 2. Required only for fSCL > 100kHz. Table 26-4. Two-wire Serial Bus Requirements Symbol Parameter Condition Min Max Units VIL Input Low-voltage -0.5 0.3 VCC V VIH Input High-voltage 0.7 VCC VCC + 0.5 V Vhys(1) Hysteresis of Schmitt Trigger Inputs 0.05 VCC(2) – V VOL(1) Output Low-voltage 3mA sink current 0 0.4 V tr (1) Rise Time for both SDA and SCL 20 + 0.1Cb (3)(2) 300 ns tof (1) Output Fall Time from VIHmin to VILmax 10 pF < Cb < 400 pF(3) 20 + 0.1Cb (3)(2) 250 ns tSP(1) Spikes Suppressed by Input Filter 0 50(2) ns Ii Input Current each I/O Pin 0.1VCC < Vi < 0.9VCC -10 10 µA Ci (1) Capacitance for each I/O Pin – 10 pF fSCL SCL Clock Frequency fCK(4) > max(16fSCL, 250kHz)(5) 0 400 kHz Rp Value of Pull-up resistor fSCL  100kHz fSCL > 100kHz tHD;STA Hold Time (repeated) START Condition fSCL  100kHz 4.0 – µs fSCL > 100kHz 0.6 – µs tLOW Low Period of the SCL Clock fSCL  100kHz(6) 4.7 – µs fSCL > 100kHz(7) 1.3 – µs tHIGH High period of the SCL clock fSCL  100kHz 4.0 – µs fSCL > 100kHz 0.6 – µs tSU;STA Set-up time for a repeated START condition fSCL  100kHz 4.7 – µs fSCL > 100kHz 0.6 – µs tHD;DAT Data hold time fSCL  100kHz 0 3.45 µs fSCL > 100kHz 0 0.9 µs tSU;DAT Data setup time fSCL  100kHz 250 – ns fSCL > 100kHz 100 – ns tSU;STO Setup time for STOP condition fSCL  100kHz 4.0 – µs fSCL > 100kHz 0.6 – µs tBUF Bus free time between a STOP and START condition fSCL  100kHz 4.7 – µs fSCL > 100kHz 1.3 – µs VCC – 0,4V 3mA ---------------------------- 1000ns Cb -------------------  VCC – 0,4V 3mA ---------------------------- 300ns Cb ---------------- ATmega8A [DATASHEET] 230 8159E–AVR–02/2013 3. Cb = capacitance of one bus line in pF. 4. fCK = CPU clock frequency 5. This requirement applies to all ATmega8A Two-wire Serial Interface operation. Other devices connected to the Two-wire Serial Bus need only obey the general fSCL requirement. 6. The actual low period generated by the ATmega8A Two-wire Serial Interface is (1/fSCL - 2/fCK), thus fCK must be greater than 6MHz for the low time requirement to be strictly met at fSCL = 100kHz. 7. The actual low period generated by the ATmega8A Two-wire Serial Interface is (1/fSCL - 2/fCK), thus the low time requirement will not be strictly met for fSCL > 308kHz when fCK = 8MHz. Still, ATmega8A devices connected to the bus may communicate at full speed (400kHz) with other ATmega8A devices, as well as any other device with a proper tLOW acceptance margin. Figure 26-3. Two-wire Serial Bus Timing 26.7 SPI Timing Characteristics See Figure 26-4 and Figure 26-5 for details. Note: 1. In SPI Programming mode the minimum SCK high/low period is: - 2tCLCL for fCK < 12MHz - 3tCLCL for fCK > 12MHz t SU;STA t LOW t HIGH t LOW t of t HD;STA t HD;DAT t SU;DAT t SU;STO t BUF SCL SDA t r Table 26-5. SPI Timing Parameters Description Mode Min Typ Max 1 SCK period Master See Table 19-4 ns 2 SCK high/low Master 50% duty cycle 3 Rise/Fall time Master 3.6 4 Setup Master 10 5 Hold Master 10 6 Out to SCK Master 0.5 • tSCK 7 SCK to out Master 10 8 SCK to out high Master 10 9 SS low to out Slave 15 10 SCK period Slave 4 • tck 11 SCK high/low(1) Slave 2 • tck 12 Rise/Fall time Slave 1.6 13 Setup Slave 10 14 Hold Slave 10 15 SCK to out Slave 15 16 SCK to SS high Slave 20 17 SS high to tri-state Slave 10 18 SS low to SCK Salve 2 • tckATmega8A [DATASHEET] 231 8159E–AVR–02/2013 Figure 26-4. SPI interface timing requirements (Master Mode) Figure 26-5. SPI interface timing requirements (Slave Mode) MOSI (Data Output) SCK (CPOL = 1) MISO (Data Input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 6 1 2 2 4 5 3 7 8 MISO (Data Output) SCK (CPOL = 1) MOSI (Data Input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 10 11 11 13 14 12 15 17 9 X 16 18ATmega8A [DATASHEET] 232 8159E–AVR–02/2013 26.8 ADC Characteristics Notes: 1. Values are guidelines only. 2. Minimum for AVCC is 2.7V. 3. Maximum for AVCC is 5.5V. 4. Maximum conversion time is 1/50kHz*25 = 0.5 ms. Table 26-6. ADC Characteristics Symbol Parameter Condition Min(1) Typ(1) Max(1) Units Resolution Single Ended Conversion 10 Bits Absolute accuracy (Including INL, DNL, Quantization Error, Gain, and Offset Error) Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 1.75 LSB Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 1MHz 3 LSB Integral Non-linearity (INL) Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 0.75 LSB Differential Non-linearity (DNL) Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 0.5 LSB Gain Error Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 1 LSB Offset Error Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 1 LSB Conversion Time(4) Free Running Conversion 13 260 µs Clock Frequency 50 1000 kHz AVCC Analog Supply Voltage VCC - 0.3(2) VCC + 0.3(3) V VREF Reference Voltage 2.0 AVCC V VIN Input voltage GND VREF V Input bandwidth 38.5 kHz VINT Internal Voltage Reference 2.3 2.56 2.8 V RREF Reference Input Resistance 32 k RAIN Analog Input Resistance 55 100 MATmega8A [DATASHEET] 233 8159E–AVR–02/2013 27. Electrical Characteristics – TA = -40°C to 105°C Absolute Maximum Ratings* 27.1 DC Characteristics Notes: 1. “Max” means the highest value where the pin is guaranteed to be read as low Operating Temperature.................................. -55C to +125C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ............................................... 40.0 mA DC Current VCC and GND Pins................................ 200.0 mA TA = -40C to 105C, VCC = 2.7V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min. Typ. Max. Units VIL Input Low Voltage, Except XTAL1 and RESET pin VCC = 2.7V - 5.5V -0.5 0.2VCC(1) V VIL1 Input Low Voltage, XTAL1 pin VCC = 2.7V - 5.5V -0.5 0.1VCC(1) V VIL2 Input Low Voltage, RESET pin VCC = 2.7V - 5.5V -0.5 0.1VCC(1) V VIH Input High Voltage, Except XTAL1 and RESET pins VCC = 2.7V - 5.5V 0.6VCC(2) VCC + 0.5 V VIH1 Input High Voltage, XTAL1 pin VCC = 2.7V - 5.5V 0.8VCC(2) VCC + 0.5 V VIH2 Input High Voltage, RESET pin VCC = 2.7V - 5.5V 0.9VCC(2) VCC + 0.5 V VOL Output Low Voltage(3), Port B (except RESET) I OL =20 mA, VCC = 5V IOL =10 mA, VCC = 3V 0.8 0.6 V VOH Output High Voltage(4), Port B (except RESET) I OH = -20 mA, VCC = 5V IOH = -10 mA, VCC = 3V 4.0 2.2 V IIL Input Leakage Current I/O Pin 3 µA IIH Input Leakage Current I/O Pin 3 µA RRST Reset Pull-up Resistor 30 80 k RPU I/O Pin Pull-up Resistor 20 50 k VACIO Analog Comparator Input Offset Voltage VCC = 5V Vin = VCC/2 20 mV IACLK Analog Comparator Input Leakage Current VCC = 5V Vin = VCC/2 -50 50 nAATmega8A [DATASHEET] 234 8159E–AVR–02/2013 2. “Min” means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP, TQFP, and QFN/MLF Package: 1] The sum of all IOL, for all ports, should not exceed 300 mA. 2] The sum of all IOL, for ports C0 - C5 should not exceed 100 mA. 3] The sum of all IOL, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 200 mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20 mA at Vcc = 5V, 10 mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP, TQFP, and QFN/MLF Package: 1] The sum of all IOH, for all ports, should not exceed 300 mA. 2] The sum of all IOH, for port C0 - C5, should not exceed 100 mA. 3] The sum of all IOH, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 200 mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. Note: 1. The current consumption values include input leakage current. 27.1.1 ATmega8A DC Characteristics Table 27-1. TA = -40C to 105C, VCC = 1.8V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min. Typ. Max. Units ICC Power Supply Current Active 4 MHz, VCC = 3V 6 mA Active 8 MHz, VCC = 5V 15 mA Idle 4 MHz, VCC = 3V 3 mA Idle 8 MHz, VCC = 5V 8 mA Power-down mode(1) WDT enabled, VCC = 3V 35 µA WDT disabled, VCC = 3V 6 µAATmega8A [DATASHEET] 235 8159E–AVR–02/2013 28. Typical Characteristics – TA = -40°C to 85°C The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A sine wave generator with Rail-to-Rail output is used as clock source. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as CL*VCC*f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. 28.1 Active Supply Current Figure 28-1. Active Supply Current vs. Frequency (0.1 - 1.0MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.3 V 2.7 V 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)ATmega8A [DATASHEET] 236 8159E–AVR–02/2013 Figure 28-2. Active Supply Current vs. Frequency (1 - 16MHz) Figure 28-3. Active Supply Current vs. VCC (Internal RC Oscillator, 8MHz) 0 2 4 6 8 10 12 14 0246 8 10 12 14 16 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.3 V 2.7 V 85 °C 25 °C -40 °C 3 4 5 6 7 8 9 10 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 237 8159E–AVR–02/2013 Figure 28-4. Active Supply Current vs. VCC (Internal RC Oscillator, 4MHz) Figure 28-5. Active Supply Current vs. VCC (Internal RC Oscillator, 2MHz) 85 °C 25 °C -40 °C 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 1.2 1.6 2 2.4 2.8 3.2 3.6 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 238 8159E–AVR–02/2013 Figure 28-6. Active Supply Current vs. VCC (Internal RC Oscillator, 1MHz) Figure 28-7. Active Supply Current vs. VCC (32kHz External Oscillator) 85 °C 25 °C -40 °C 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 25 °C 40 45 50 55 60 65 70 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)ATmega8A [DATASHEET] 239 8159E–AVR–02/2013 28.2 Idle Supply Current Figure 28-8. Idle Supply Current vs. Frequency (0.1 - 1.0MHz) Figure 28-9. Idle Supply Current vs. Frequency (1 - 16MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.3 V 2.7 V 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.3 V 2.7 V 0 1 2 3 4 5 6 0246 8 10 12 14 16 Frequency (MHz) ICC (mA)ATmega8A [DATASHEET] 240 8159E–AVR–02/2013 Figure 28-10. Idle Supply Current vs. VCC (Internal RC Oscillator, 8MHz) Figure 28-11. Idle Supply Current vs. VCC (Internal RC Oscillator, 4MHz) 85 °C 25 °C -40 °C 1 1.5 2 2.5 3 3.5 4 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 241 8159E–AVR–02/2013 Figure 28-12. Idle Supply Current vs. VCC (Internal RC Oscillator, 2MHz) Figure 28-13. Idle Supply Current vs. VCC (Internal RC Oscillator, 1MHz) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 242 8159E–AVR–02/2013 Figure 28-14. Idle Supply Current vs. VCC (32kHz External Oscillator) 28.3 Power-down Supply Current Figure 28-15. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) 25 °C 0 5 10 15 20 25 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 243 8159E–AVR–02/2013 Figure 28-16. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) 28.4 Power-save Supply Current Figure 28-17. Power-save Supply Current vs. VCC (Watchdog Timer Disabled) 85 °C 25 °C -40 °C 0 5 10 15 20 25 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25 °C 2 4 6 8 10 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 244 8159E–AVR–02/2013 28.5 Standby Supply Current Figure 28-18. Standby Supply Current vs. VCC (455kHz Resonator, Watchdog Timer Disabled) Figure 28-19. Standby Supply Current vs. VCC (1MHz Resonator, Watchdog Timer Disabled) 25 °C 0 10 20 30 40 50 60 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25 °C 0 10 20 30 40 50 60 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 245 8159E–AVR–02/2013 Figure 28-20. Standby Supply Current vs. VCC (1MHz Xtal, Watchdog Timer Disabled) Figure 28-21. Standby Supply Current vs. VCC (4MHz Resonator, Watchdog Timer Disabled) 25 °C 0 10 20 30 40 50 60 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25 °C 0 15 30 45 60 75 90 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 246 8159E–AVR–02/2013 Figure 28-22. Standby Supply Current vs. VCC (4MHz Xtal, Watchdog Timer Disabled) Figure 28-23. Standby Supply Current vs. VCC (6MHz Resonator, Watchdog Timer Disabled) 25 °C 0 10 20 30 40 50 60 70 80 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25 °C 0 20 40 60 80 100 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 247 8159E–AVR–02/2013 Figure 28-24. Standby Supply Current vs. VCC (6MHz Xtal, Watchdog Timer Disabled) 28.6 Pin Pull-up Figure 28-25. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 5V) 25 °C 0 20 40 60 80 100 120 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 0 20 40 60 80 100 120 140 0123456 VOP (V) IOP (uA) 85 °C 25 °C -40 °CATmega8A [DATASHEET] 248 8159E–AVR–02/2013 Figure 28-26. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 2.7V) Figure 28-27. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 70 80 0 0.5 1 1.5 2 2.5 3 VOP (V) IOP (uA) 85 °C 25 °C -40 °C 0 20 40 60 80 100 120 012345 VRESET (V) IRESET (uA)ATmega8A [DATASHEET] 249 8159E–AVR–02/2013 Figure 28-28. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) 28.7 Pin Driver Strength Figure 28-29. I/O Pin Output Voltage vs. Source Current (VCC = 5.0V) 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 0 0.5 1 1.5 2 2.5 3 VRESET (V) IRESET (uA) 85 °C 25 °C -40 °C 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 0246 8 10 12 14 16 18 20 IOH (mA) VOH ( V)ATmega8A [DATASHEET] 250 8159E–AVR–02/2013 Figure 28-30. I/O Pin Output Voltage vs. Source Current (VCC = 3.0V) Figure 28-31. I/O Pin Output Voltage vs. Sink Current (VCC = 5.0V) 85 °C 25 °C -40 °C 1 1.5 2 2.5 3 3.5 0 4 8 12 16 20 IOH (mA) VOH ( V) 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0 4 8 12 16 20 IOL (mA) VOL ( V)ATmega8A [DATASHEET] 251 8159E–AVR–02/2013 Figure 28-32. I/O Pin Output Voltage vs. Sink Current (VCC = 3.0V) Figure 28-33. Reset Pin as I/O - Pin Source Current vs. Output Voltage (VCC = 5.0V) 85 °C 25 °C -40 °C 0 0.2 0.4 0.6 0.8 1 0246 8 10 12 14 16 18 20 IOL (mA) VOL ( V) 0 1 2 3 4 5 2 2.5 3 3.5 4 4.5 VOH (V) Current (mA) 85 °C 25 °C -40 °CATmega8A [DATASHEET] 252 8159E–AVR–02/2013 Figure 28-34. Reset Pin as I/O - Pin Source Current vs. Output Voltage (VCC = 2.7V) Figure 28-35. Reset Pin as I/O - Pin Sink Current vs. Output Voltage (VCC = 5.0V) 0 0.5 1 1.5 2 2.5 3 3.5 4 0 0.5 1 1.5 2 2.5 VOH (V) Current (mA) 85 °C 25 °C -40 °C 85 °C 25 °C -40 °C 0 2 4 6 8 10 12 14 0 0.5 1 1.5 2 VOL (V) Current (mA)ATmega8A [DATASHEET] 253 8159E–AVR–02/2013 Figure 28-36. Reset Pin as I/O - Pin Sink Current vs. Output Voltage (VCC = 2.7V) 28.8 Pin Thresholds and Hysteresis Figure 28-37. I/O Pin Input Threshold Voltage vs. VCC (VIH, I/O Pin Read as “1”) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 0.5 1 1.5 2 VOL (V) Current (mA) 85 °C 25 °C -40 °C 1 1.5 2 2.5 3 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold ( V)ATmega8A [DATASHEET] 254 8159E–AVR–02/2013 Figure 28-38. I/O Pin Input Threshold Voltage vs. VCC (VIL, I/O Pin Read as “0”) Figure 28-39. I/O Pin Input Hysteresis vs. VCC 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold ( V) 85 °C 25 °C -40 °C 0.2 0.25 0.3 0.35 0.4 0.45 0.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (m V)ATmega8A [DATASHEET] 255 8159E–AVR–02/2013 Figure 28-40. Reset Pin as I/O - Input Threshold Voltage vs. VCC (VIH, Reset Pin Read as “1”) Figure 28-41. Reset Pin as I/O - Input Threshold Voltage vs. VCC (VIL, Reset Pin Read as “0”) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold ( V) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold ( V)ATmega8A [DATASHEET] 256 8159E–AVR–02/2013 Figure 28-42. Reset Pin as I/O - Pin Hysteresis vs. VCC Figure 28-43. Reset Input Threshold Voltage vs. VCC (VIH, Reset Pin Read as “1”) 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (m V) 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold ( V)ATmega8A [DATASHEET] 257 8159E–AVR–02/2013 Figure 28-44. Reset Input Threshold Voltage vs. VCC (VIL, Reset Pin Read as “0”) Figure 28-45. Reset Input Pin Hysteresis vs. VCC 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold ( V) 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (m V)ATmega8A [DATASHEET] 258 8159E–AVR–02/2013 28.9 Bod Thresholds and Analog Comparator Offset Figure 28-46. BOD Thresholds vs. Temperature (BOD Level is 4.0V) Figure 28-47. BOD Thresholds vs. Temperature (BOD Level is 2.7v) 3.7 3.75 3.8 3.85 3.9 3.95 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Threshold ( V) Rising Vcc Falling Vcc Temperature (°C) 2.5 2.55 2.6 2.65 2.7 2.75 2.8 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature (°C) Threshold ( V) Rising Vcc Falling VccATmega8A [DATASHEET] 259 8159E–AVR–02/2013 Figure 28-48. Bandgap Voltage vs. VCC Figure 28-49. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 5V) 85 °C 25 °C -40 °C 1.18 1.185 1.19 1.195 1.2 1.205 1.21 1.215 2.5 3 3.5 4 4.5 5 5.5 Vcc (V) Bandgap Voltage ( V) Comparator Offset Voltage (V) 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Common Mode Voltage (V) 85 °C 25 °C -40 °C -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003ATmega8A [DATASHEET] 260 8159E–AVR–02/2013 Figure 28-50. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 2.8V) 28.10 Internal Oscillator Speed Figure 28-51. Watchdog Oscillator Frequency vs. VCC -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003 0.25 0.50 0.75 1.00 1.25 1.5 1.75 2.00 2.25 2.75 Common Mode Voltage (V) 2.50 Comparator Offset Voltage (V) 85 °C 25 °C -40 °C 85 °C 25 °C -40 °C 925 950 975 1000 1025 1050 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (kHz)ATmega8A [DATASHEET] 261 8159E–AVR–02/2013 Figure 28-52. Calibrated 8MHz RC Oscillator Frequency vs. Temperature Figure 28-53. Calibrated 8MHz RC Oscillator Frequency vs. VCC 5.5 V 4.0 V 2.7 V 6 6,5 7 7,5 8 8,5 -40 -20 0 20 40 60 80 100 Temperature (°C) FRC (MHz) 85 °C 25 °C -40 °C 6 6.5 7 7.5 8 8.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz)ATmega8A [DATASHEET] 262 8159E–AVR–02/2013 Figure 28-54. Calibrated 8MHz RC Oscillator Frequency vs. Osccal Value Figure 28-55. Calibrated 4MHz RC Oscillator Frequency vs. Temperature 25 °C 2 4 6 8 10 12 14 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL VALUE FRC (MHz) 5.5 V 4.0 V 2.7 V 3.5 3.6 3.7 3.8 3.9 4 4.1 -40 -20 0 20 40 60 80 100 FRC (MHz) Temperature (°C)ATmega8A [DATASHEET] 263 8159E–AVR–02/2013 Figure 28-56. Calibrated 4MHz RC Oscillator Frequency vs. VCC Figure 28-57. Calibrated 4MHz RC Oscillator Frequency vs. Osccal Value 85 °C 25 °C -40 °C 3.5 3.6 3.7 3.8 3.9 4 4.1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 25 °C 1 2 3 4 5 6 7 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL VALUE FRC (MHz)ATmega8A [DATASHEET] 264 8159E–AVR–02/2013 Figure 28-58. Calibrated 2MHz RC Oscillator Frequency vs. Temperature Figure 28-59. Calibrated 2MHz RC Oscillator Frequency vs. VCC 5.5 V 4.0 V 2.7 V 1.75 1.8 1.85 1.9 1.95 2 2.05 2.1 -40 -20 0 20 40 60 80 100 FRC (MHz) Temperature (°C) 85 °C 25 °C -40 °C 1.8 1.85 1.9 1.95 2 2.05 2.1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz)ATmega8A [DATASHEET] 265 8159E–AVR–02/2013 Figure 28-60. Calibrated 2MHz RC Oscillator Frequency vs. Osccal Value Figure 28-61. Calibrated 1MHz RC Oscillator Frequency vs. Temperature 25 °C 0.5 1 1.5 2 2.5 3 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL VALUE FRC (MHz) 5.5 V 4.0 V 2.7 V 0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 -40 -20 0 20 40 60 80 100 FRC (MHz) Temperature (°C)ATmega8A [DATASHEET] 266 8159E–AVR–02/2013 Figure 28-62. Calibrated 1MHz RC Oscillator Frequency vs. VCC Figure 28-63. Calibrated 1MHz RC Oscillator Frequency vs. Osccal Value 85 °C 25 °C -40 °C 0,9 0.92 0.94 0.96 0.98 1 1.02 1.04 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 25 °C 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL VALUE FRC (MHz)ATmega8A [DATASHEET] 267 8159E–AVR–02/2013 28.11 Current Consumption of Peripheral Units Figure 28-64. Brown-out Detector Current vs. VCC Figure 28-65. ADC Current vs. VCC (AREF = AVCC) 85 °C 25 °C -40 °C 0 4 8 12 16 20 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 100 125 150 175 200 225 250 275 300 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 268 8159E–AVR–02/2013 Figure 28-66. AREF External Reference Current vs. VCC Figure 28-67. 32kHz TOSC Current vs. VCC (Watchdog Timer Disabled) 85 °C 25 °C -40 °C 40 60 80 100 120 140 160 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 2 4 6 8 10 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 269 8159E–AVR–02/2013 Figure 28-68. Watchdog Timer Current vs. VCC Figure 28-69. Analog Comparator Current vs. VCC 85 °C 25 °C -40 °C 0 4 8 12 16 20 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 70 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 270 8159E–AVR–02/2013 Figure 28-70. Programming Current vs. VCC 28.12 Current Consumption in Reset and Reset Pulsewidth Figure 28-71. Reset Supply Current vs. VCC (0.1 - 1.0MHz, Excluding Current Through The Reset Pull-up) 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.3 V 2.7 V 0 0.5 1 1.5 2 2.5 3 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)ATmega8A [DATASHEET] 271 8159E–AVR–02/2013 Figure 28-72. Reset Supply Current vs. VCC (1 - 16MHz, Excluding Current Through The Reset Pull-up) Figure 28-73. Reset Pulse Width vs. VCC 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.3 V 2.7 V 0 2 4 6 8 10 12 0246 8 10 12 14 16 Frequency (MHz) ICC (mA) 85 °C 25 °C -40 °C 0 150 300 450 600 750 2,5 3 3,5 4 4,5 5 5,5 V CC (V) Pulsewidth (ns)ATmega8A [DATASHEET] 272 8159E–AVR–02/2013 29. Typical Characteristics – TA = -40°C to 105°C The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A sine wave generator with rail-to-rail output is used as clock source. All Active- and Idle current consumption measurements are done with all bits in the PRR registers set and thus, the corresponding I/O modules are turned off. Also the Analog Comparator is disabled during these measurements. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as CL*VCC*f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. 29.1 ATmega8A Typical Characteristics 29.1.1 Active Supply Current Figure 29-1. Active Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) 105 °C 85 °C 25 °C -40 °C 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 273 8159E–AVR–02/2013 Figure 29-2. Active Supply Current vs. VCC (Internal RC Oscillator, 4 MHz) Figure 29-3. Active Supply Current vs. VCC (Internal RC Oscillator, 2 MHz) 105 °C 85 °C 25 °C -40 °C 1.5 2 2.5 3 3.5 4 4.5 5 5.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA) 105 °C 85 °C 25 °C -40 °C 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 274 8159E–AVR–02/2013 Figure 29-4. Active Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) Figure 29-5. Active Supply Current vs. VCC (32 kHz External Oscillator) 105 °C 85 °C 25 °C -40 °C 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA) 105 °C 85 °C 25 °C -40 °C 35 38 41 44 47 50 53 56 59 62 65 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 275 8159E–AVR–02/2013 29.1.2 Idle Supply Current Figure 29-6. Idle Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) Figure 29-7. Idle Supply Current vs. VCC (Internal RC Oscillator, 4 MHz) 105 °C 85 °C 25 °C -40 °C 1.2 1.5 1.8 2.1 2.4 2.7 3 3.3 3.6 3.9 4.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA) 105 °C 85 °C 25 °C -40 °C 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 276 8159E–AVR–02/2013 Figure 29-8. Idle Supply Current vs. VCC (Internal RC Oscillator, 2 MHz) Figure 29-9. Idle Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) 105 °C 85 °C 25 °C -40 °C 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA) 105 °C 85 °C 25 °C -40 °C 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA)ATmega8A [DATASHEET] 277 8159E–AVR–02/2013 Figure 29-10. Idle Supply Current vs. VCC (32 kHz External RC Oscillator) 29.1.3 Power-down Supply Current Figure 29-11. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) 105 °C 85 °C 25 °C -40 °C 6.5 8.5 10.5 12.5 14.5 16.5 18.5 20.5 22.5 24.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA) 105 °C 85 °C 25 °C -40 °C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 278 8159E–AVR–02/2013 Figure 29-12. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) 29.1.4 Power-save Supply Current Figure 29-13. Power-save Supply Current vs. VCC (Watchdog Timer Disabled) 105 °C 85 °C 25 °C -40 °C 3 6 9 12 15 18 21 24 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA) 105 °C 85 °C 25 °C -40 °C 4 5 6 7 8 9 10 11 12 13 14 15 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 279 8159E–AVR–02/2013 29.1.5 Standby Supply Current Figure 29-14. Standby Supply Current vs. VCC (32 kHz External RC Oscillator) 29.1.6 Pin Pull-up Figure 29-15. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 5V) 105 °C 85 °C 25 °C -40 °C 7 9 11 13 15 17 19 21 23 25 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA) 0 20 40 60 80 100 120 140 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VOP (V) IOP (uA) 105 °C 85 °C 25 °C -40 °CATmega8A [DATASHEET] 280 8159E–AVR–02/2013 Figure 29-16. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 2.7V) Figure 29-17. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) 105 °C 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 70 80 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 VOP (V) IOP (uA) 0 10 20 30 40 50 60 70 80 90 100 110 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VRESET (V) IRESET (uA) 105 °C 85 °C 25 °C -40 °CATmega8A [DATASHEET] 281 8159E–AVR–02/2013 Figure 29-18. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) 29.1.7 Pin Driver Strength Figure 29-19. I/O Pin Output Voltage vs. Source Current (VCC = 5V) 105 °C 85 °C 25 °C -40 °C 0 10 20 30 40 50 60 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 VRESET (V) IRESET (uA) 105 °C 85 °C 25 °C -40 °C 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 5.1 0246 8 10 12 14 16 18 20 IOH (mA) VOH ( V)ATmega8A [DATASHEET] 282 8159E–AVR–02/2013 Figure 29-20. I/O Pin Output Voltage vs. Source Current (VCC = 3V) Figure 29-21. I/O Pin Output Voltage vs. Sink Current (VCC = 5V) 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 0246 8 10 12 14 16 18 20 IOH (mA) VOH ( V) 105 °C 85 °C 25 °C -40 °C 105 °C 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0246 8 10 12 14 16 18 20 IOL (mA) VOL ( V)ATmega8A [DATASHEET] 283 8159E–AVR–02/2013 Figure 29-22. I/O Pin Output Voltage vs. Sink Current (VCC = 3V) 29.1.8 Pin Threshold and Hysteresis Figure 29-23. I/O Pin Input Threshold vs. VCC (VIH , I/O Pin Read as ‘1’) 105 °C 85 °C 25 °C -40 °C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0246 8 10 12 14 16 18 20 IOL(mA) VOL ( V) 105 °C 85 °C 25 °C -40 °C 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Threshold ( V)ATmega8A [DATASHEET] 284 8159E–AVR–02/2013 Figure 29-24. I/O Pin Input Threshold vs. VCC (VIL, I/O Pin Read as ‘0’) Figure 29-25. I/O Pin Input Hysteresis vs. VCC 105 °C 85 °C 25 °C -40 °C 1 1.3 1.6 1.9 2.2 2.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Threshold ( V) 105 °C 85 °C 25 °C -40 °C 0.25 0.3 0.35 0.4 0.45 0.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Input Hysteresis (m V)ATmega8A [DATASHEET] 285 8159E–AVR–02/2013 Figure 29-26. Reset Pin as I/O - Input Threshold vs. VCC (VIH , I/O Pin Read as ‘1’) Figure 29-27. Reset Pin as I/O - Input Threshold vs. VCC (VIL, I/O Pin Read as ‘0’) 105 °C 85 °C 25 °C -40 °C 1.3 1.6 1.9 2.2 2.5 2.8 3.1 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Threshold ( V) 105 °C 85 °C 25 °C -40 °C 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Threshold ( V)ATmega8A [DATASHEET] 286 8159E–AVR–02/2013 Figure 29-28. Reset Pin as I/O - Pin Hysteresis vs. VCC Figure 29-29. Reset Input Threshold vs. VCC (VIH , Reset Pin Read as ‘1’) 105 °C 85 °C 25 °C -40 °C 0.4 0.45 0.5 0.55 0.6 0.65 0.7 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Input Hysteresis (m V) 105 °C 85 °C 25 °C -40 °C 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Threshold ( V)ATmega8A [DATASHEET] 287 8159E–AVR–02/2013 Figure 29-30. Reset Input Threshold vs. VCC (VIL, Reset Pin Read as ‘0’) Figure 29-31. Reset Pin Input Hysteresis vs. VCC 105 °C 85 °C 25 °C -40 °C 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Threshold ( V) 105 °C 85 °C 25 °C -40 °C 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Input Hysteresis (m V)ATmega8A [DATASHEET] 288 8159E–AVR–02/2013 29.1.9 BOD Threshold Figure 29-32. BOD Threshold vs. Temperature (VCC = 4.3V) Figure 29-33. BOD Threshold vs. Temperature (VCC = 2.7V) Rising Vcc Falling Vcc 3.8 3.82 3.84 3.86 3.88 3.9 3.92 3.94 3.96 3.98 4 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) Threshold ( V) Rising Vcc Falling Vcc 2.47 2.49 2.51 2.53 2.55 2.57 2.59 2.61 2.63 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) Threshold ( V)ATmega8A [DATASHEET] 289 8159E–AVR–02/2013 Figure 29-34. Bandgap Voltage vs. Temperature Figure 29-35. Bandgap Voltage vs. VCC 5.5V 5.0V 4.0V 3.3V 2.7V 1.8V 1.175 1.18 1.185 1.19 1.195 1.2 1.205 1.21 1.215 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) Bandgap Voltage ( V) 105 °C 85 °C 25 °C -40 °C 1.175 1.18 1.185 1.19 1.195 1.2 1.205 1.21 1.215 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Bandgap Voltage ( V)ATmega8A [DATASHEET] 290 8159E–AVR–02/2013 29.1.10 Internal Oscillator Speed Figure 29-36. Watchdog Oscillator Frequency vs. VCC Figure 29-37. Watchdog Oscillator Frequency vs. Temperature 105 °C 85 °C 25 °C -40 °C 980 1000 1020 1040 1060 1080 1100 1120 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) FRC (kHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 2.7 V 970 990 1010 1030 1050 1070 1090 1110 1130 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) FRC (kHz)ATmega8A [DATASHEET] 291 8159E–AVR–02/2013 Figure 29-38. Calibrated 8 MHz RC Oscillator vs. Temperature Figure 29-39. Calibrated 8 MHz RC Oscillator vs. VCC 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.0 V 2.7 V 6.6 6.8 7 7.2 7.4 7.6 7.8 8 8.2 8.4 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) FRC (MHz) 105 °C 85 °C 25 °C -40 °C 6.6 6.8 7 7.2 7.4 7.6 7.8 8 8.2 8.4 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) FRC (MHz)ATmega8A [DATASHEET] 292 8159E–AVR–02/2013 Figure 29-40. Calibrated 8 MHz RC Oscillator vs. OSCCAL Value Figure 29-41. Calibrated 4 MHz RC Oscillator vs. Temperature 105 °C 85 °C 25 °C -40 °C 2 4 6 8 10 12 14 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL (X1) FRC (MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.0 V 2.7 V 3.55 3.65 3.75 3.85 3.95 4.05 4.15 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) FRC (MHz)ATmega8A [DATASHEET] 293 8159E–AVR–02/2013 Figure 29-42. Calibrated 4 MHz RC Oscillator vs. VCC Figure 29-43. Calibrated 4 MHz RC Oscillator vs. OSCCAL Value 105 °C 85 °C 25 °C -40 °C 3.6 3.65 3.7 3.75 3.8 3.85 3.9 3.95 4 4.05 4.1 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) FRC (MHz) 105 °C 85 °C 25 °C -40 °C 1 2 3 4 5 6 7 8 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL (X1) FRC (MHz)ATmega8A [DATASHEET] 294 8159E–AVR–02/2013 Figure 29-44. Calibrated 2 MHz RC Oscillator vs. Temperature Figure 29-45. Calibrated 2 MHz RC Oscillator vs. VCC 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.0 V 2.7 V 1.78 1.81 1.84 1.87 1.9 1.93 1.96 1.99 2.02 2.05 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) FRC (MHz) 105 °C 85 °C 25 °C -40 °C 1.8 1.83 1.86 1.89 1.92 1.95 1.98 2.01 2.04 2.07 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) FRC (MHz)ATmega8A [DATASHEET] 295 8159E–AVR–02/2013 Figure 29-46. Calibrated 2 MHz RC Oscillator vs. OSCCAL Value Figure 29-47. Calibrated 1 MHz RC Oscillator vs. Temperature 105 °C 85 °C 25 °C -40 °C 0.8 1.1 1.4 1.7 2 2.3 2.6 2.9 3.2 3.5 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL (X1) FRC (MHz) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 3.0 V 2.7 V 0.91 0.93 0.95 0.97 0.99 1.01 1.03 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) FRC (MHz)ATmega8A [DATASHEET] 296 8159E–AVR–02/2013 Figure 29-48. Calibrated 1 MHz RC Oscillator vs. VCC Figure 29-49. Calibrated 1 MHz RC Oscillator vs. OSCCAL Value 105 °C 85 °C 25 °C -40 °C 0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) FRC (MHz) 105 °C 85 °C 25 °C -40 °C 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 OSCCAL (X1) FRC (MHz)ATmega8A [DATASHEET] 297 8159E–AVR–02/2013 29.1.11 Current Consumption of Peripheral Units Figure 29-50. Brown-out Detector Current vs. VCC Figure 29-51. ADC Current vs. VCC (AREF = AVCC) 105 °C 85 °C 25 °C -40 °C 8 9 10 11 12 13 14 15 16 17 18 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA) 105 °C 85 °C 25 °C -40 °C 140 160 180 200 220 240 260 280 300 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA)ATmega8A [DATASHEET] 298 8159E–AVR–02/2013 Figure 29-52. Watchdog Timer Current vs. VCC Figure 29-53. Analog Comparator Current vs. VCC 4 6 8 10 12 14 16 18 20 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (uA) 105 °C 85 °C 25 °C -40 °C 32 36 40 44 48 52 56 60 64 68 72 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA) 105 °C 85 °C 25 °C -40 °CATmega8A [DATASHEET] 299 8159E–AVR–02/2013 Figure 29-54. Programming Current vs. VCC 29.1.12 Current Consumption in Reset and Reset Pulsewidth Figure 29-55. Reset Supply Current vs. Vcc (0.1 - 1.0 MHz, Excluding Current Through the Reset Pull-up) 105 °C 85 °C 25 °C -40 °C 0 1 2 3 4 5 6 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) ICC (mA) 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 2.7 V 0 0.5 1 1.5 2 2.5 3 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)ATmega8A [DATASHEET] 300 8159E–AVR–02/2013 Figure 29-56. Reset Supply Current vs. Vcc (1 - 16 MHz, Excluding Current Through the Reset Pull-up) Figure 29-57. Minimum Reset Pulsewidth vs. Vcc 5.5 V 5.0 V 4.5 V 4.0 V 3.6 V 2.7 V 0 2 4 6 8 10 12 0246 8 10 12 14 16 Frequency (MHz) ICC (mA) 105 °C 85 °C 25 °C -40 °C 100 200 300 400 500 600 700 800 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 VCC (V) Pulse width (ns)ATmega8A [DATASHEET] 301 8159E–AVR–02/2013 30. Register Summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page 0x3F (0x5F) SREG I T H S V N Z C 8 0x3E (0x5E) SPH – – – – – SP10 SP9 SP8 10 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 10 0x3C (0x5C) Reserved 0x3B (0x5B) GICR INT1 INT0 – – – – IVSEL IVCE 47, 65 0x3A (0x5A) GIFR INTF1 INTF0 – – – – – – 65 0x39 (0x59) TIMSK OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 69, 97, 115 0x38 (0x58) TIFR OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 70, 97, 97 0x37 (0x57) SPMCR SPMIE RWWSB – RWWSRE BLBSET PGWRT PGERS SPMEN 205 0x36 (0x56) TWCR TWINT TWEA TWSTA TWSTO TWWC TWEN – TWIE 176 0x35 (0x55) MCUCR SE SM2 SM1 SM0 ISC11 ISC10 ISC01 ISC00 35, 64 0x34 (0x54) MCUCSR – – – – WDRF BORF EXTRF PORF 42 0x33 (0x53) TCCR0 – – – – – CS02 CS01 CS00 69 0x32 (0x52) TCNT0 Timer/Counter0 (8 Bits) 69 0x31 (0x51) OSCCAL Oscillator Calibration Register 31 0x30 (0x50) SFIOR – – – – ACME PUD PSR2 PSR10 55, 72, 115, 180 0x2F (0x4F) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 FOC1A FOC1B WGM11 WGM10 92 0x2E (0x4E) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 95 0x2D (0x4D) TCNT1H Timer/Counter1 – Counter Register High byte 96 0x2C (0x4C) TCNT1L Timer/Counter1 – Counter Register Low byte 96 0x2B (0x4B) OCR1AH Timer/Counter1 – Output Compare Register A High byte 96 0x2A (0x4A) OCR1AL Timer/Counter1 – Output Compare Register A Low byte 96 0x29 (0x49) OCR1BH Timer/Counter1 – Output Compare Register B High byte 96 0x28 (0x48) OCR1BL Timer/Counter1 – Output Compare Register B Low byte 96 0x27 (0x47) ICR1H Timer/Counter1 – Input Capture Register High byte 96 0x26 (0x46) ICR1L Timer/Counter1 – Input Capture Register Low byte 96 0x25 (0x45) TCCR2 FOC2 WGM20 COM21 COM20 WGM21 CS22 CS21 CS20 112 0x24 (0x44) TCNT2 Timer/Counter2 (8 Bits) 113 0x23 (0x43) OCR2 Timer/Counter2 Output Compare Register 114 0x22 (0x42) ASSR – – – – AS2 TCN2UB OCR2UB TCR2UB 114 0x21 (0x41) WDTCR – – – WDCE WDE WDP2 WDP1 WDP0 42 0x20(1) (0x40)(1) UBRRH URSEL – – – UBRR[11:8] 147 UCSRC URSEL UMSEL UPM1 UPM0 USBS UCSZ1 UCSZ0 UCPOL 145 0x1F (0x3F) EEARH – – – – – – – EEAR8 18 0x1E (0x3E) EEARL EEAR7 EEAR6 EEAR5 EEAR4 EEAR3 EEAR2 EEAR1 EEAR0 18 0x1D (0x3D) EEDR EEPROM Data Register 18 0x1C (0x3C) EECR – – – – EERIE EEMWE EEWE EERE 18 0x1B (0x3B) Reserved 0x1A (0x3A) Reserved 0x19 (0x39) Reserved 0x18 (0x38) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 62 0x17 (0x37) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 62 0x16 (0x36) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 63 0x15 (0x35) PORTC – PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 63 0x14 (0x34) DDRC – DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 63 0x13 (0x33) PINC – PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 63 0x12 (0x32) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 63 0x11 (0x31) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 63 0x10 (0x30) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 63 0x0F (0x2F) SPDR SPI Data Register 124 0x0E (0x2E) SPSR SPIF WCOL – – – – – SPI2X 124 0x0D (0x2D) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 123 0x0C (0x2C) UDR USART I/O Data Register 143 0x0B (0x2B) UCSRA RXC TXC UDRE FE DOR PE U2X MPCM 144 0x0A (0x2A) UCSRB RXCIE TXCIE UDRIE RXEN TXEN UCSZ2 RXB8 TXB8 145 0x09 (0x29) UBRRL USART Baud Rate Register Low byte 147 0x08 (0x28) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 180 0x07 (0x27) ADMUX REFS1 REFS0 ADLAR – MUX3 MUX2 MUX1 MUX0 190 0x06 (0x26) ADCSRA ADEN ADSC ADFR ADIF ADIE ADPS2 ADPS1 ADPS0 191 0x05 (0x25) ADCH ADC Data Register High byte 193 0x04 (0x24) ADCL ADC Data Register Low byte 193 0x03 (0x23) TWDR Two-wire Serial Interface Data Register 178 0x02 (0x22) TWAR TWA6 TWA5 TWA4 TWA3 TWA2 TWA1 TWA0 TWGCE 178 0x01 (0x21) TWSR TWS7 TWS6 TWS5 TWS4 TWS3 – TWPS1 TWPS0 177 0x00 (0x20) TWBR Two-wire Serial Interface Bit Rate Register 176ATmega8A [DATASHEET] 302 8159E–AVR–02/2013 Note: 1. Refer to the USART description for details on how to access UBRRH and UCSRC. 2. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 3. Some of the Status Flags are cleared by writing a logical one to them. Note that the CBI and SBI instructions will operate on all bits in the I/O Register, writing a one back into any flag read as set, thus clearing the flag. The CBI and SBI instructions work with registers 0x00 to 0x1F only.ATmega8A [DATASHEET] 303 8159E–AVR–02/2013 31. Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd  Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd  Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl  Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd  Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd  Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd  Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd  Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl  Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd Rd  Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd  Rd K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd  Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd  Rd  Rr Z,N,V 1 COM Rd One’s Complement Rd  0xFF  Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd  0x00  Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd  Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd  Rd  (0xFF - K) Z,N,V 1 INC Rd Increment Rd  Rd + 1 Z,N,V 1 DEC Rd Decrement Rd  Rd  1 Z,N,V 1 TST Rd Test for Zero or Minus Rd  Rd  Rd Z,N,V 1 CLR Rd Clear Register Rd  Rd  Rd Z,N,V 1 SER Rd Set Register Rd  0xFF None 1 MUL Rd, Rr Multiply Unsigned R1:R0  Rd x Rr Z,C 2 MULS Rd, Rr Multiply Signed R1:R0  Rd x Rr Z,C 2 MULSU Rd, Rr Multiply Signed with Unsigned R1:R0  Rd x Rr Z,C 2 FMUL Rd, Rr Fractional Multiply Unsigned R1:R0  (Rd x Rr) << 1 Z,C 2 FMULS Rd, Rr Fractional Multiply Signed R1:R0  (Rd x Rr) << 1 Z,C 2 FMULSU Rd, Rr Fractional Multiply Signed with Unsigned R1:R0  (Rd x Rr) << 1 Z,C 2 BRANCH INSTRUCTIONS RJMP k Relative Jump PC PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC  Z None 2 RCALL k Relative Subroutine Call PC  PC + k + 1 None 3 ICALL Indirect Call to (Z) PC  Z None 3 RET Subroutine Return PC  STACK None 4 RETI Interrupt Return PC  STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC PC + 2 or 3 None 1 / 2 / 3 CP Rd,Rr Compare Rd  Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd  Rr  C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd  K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC  PC + 2 or 3 None 1 / 2 / 3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC  PC + 2 or 3 None 1 / 2 / 3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC  PC + 2 or 3 None 1 / 2 / 3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC  PC + 2 or 3 None 1 / 2 / 3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PCPC+k + 1 None 1 / 2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PCPC+k + 1 None 1 / 2 BREQ k Branch if Equal if (Z = 1) then PC  PC + k + 1 None 1 / 2 BRNE k Branch if Not Equal if (Z = 0) then PC  PC + k + 1 None 1 / 2 BRCS k Branch if Carry Set if (C = 1) then PC  PC + k + 1 None 1 / 2 BRCC k Branch if Carry Cleared if (C = 0) then PC  PC + k + 1 None 1 / 2 BRSH k Branch if Same or Higher if (C = 0) then PC  PC + k + 1 None 1 / 2 BRLO k Branch if Lower if (C = 1) then PC  PC + k + 1 None 1 / 2 BRMI k Branch if Minus if (N = 1) then PC  PC + k + 1 None 1 / 2 BRPL k Branch if Plus if (N = 0) then PC  PC + k + 1 None 1 / 2 BRGE k Branch if Greater or Equal, Signed if (N  V= 0) then PC  PC + k + 1 None 1 / 2 BRLT k Branch if Less Than Zero, Signed if (N  V= 1) then PC  PC + k + 1 None 1 / 2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC  PC + k + 1 None 1 / 2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC  PC + k + 1 None 1 / 2 BRTS k Branch if T Flag Set if (T = 1) then PC  PC + k + 1 None 1 / 2 BRTC k Branch if T Flag Cleared if (T = 0) then PC  PC + k + 1 None 1 / 2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC  PC + k + 1 None 1 / 2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC  PC + k + 1 None 1 / 2 Mnemonics Operands Description Operation Flags #Clocks BRIE k Branch if Interrupt Enabled if ( I = 1) then PC  PC + k + 1 None 1 / 2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC  PC + k + 1 None 1 / 2ATmega8A [DATASHEET] 304 8159E–AVR–02/2013 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd  Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd  Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd  K None 1 LD Rd, X Load Indirect Rd  (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd  (X), X  X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X  X - 1, Rd  (X) None 2 LD Rd, Y Load Indirect Rd  (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd  (Y), Y  Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y  Y - 1, Rd  (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd  (Y + q) None 2 LD Rd, Z Load Indirect Rd  (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd  (Z), Z  Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z  Z - 1, Rd  (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd  (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd  (k) None 2 ST X, Rr Store Indirect (X) Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) Rr, X  X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X  X - 1, (X)  Rr None 2 ST Y, Rr Store Indirect (Y)  Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y)  Rr, Y  Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y  Y - 1, (Y)  Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q)  Rr None 2 ST Z, Rr Store Indirect (Z)  Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z)  Rr, Z  Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z  Z - 1, (Z)  Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q)  Rr None 2 STS k, Rr Store Direct to SRAM (k)  Rr None 2 LPM Load Program Memory R0  (Z) None 3 LPM Rd, Z Load Program Memory Rd  (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd  (Z), Z  Z+1 None 3 SPM Store Program Memory (Z)  R1:R0 None - IN Rd, P In Port Rd  P None 1 OUT P, Rr Out Port P  Rr None 1 PUSH Rr Push Register on Stack STACK  Rr None 2 POP Rd Pop Register from Stack Rd  STACK None 2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b)  1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b)  0 None 2 LSL Rd Logical Shift Left Rd(n+1)  Rd(n), Rd(0)  0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n)  Rd(n+1), Rd(7)  0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)C,Rd(n+1) Rd(n),CRd(7) Z,C,N,V 1 ROR Rd Rotate Right Through Carry Rd(7)C,Rd(n) Rd(n+1),CRd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n)  Rd(n+1), n=0:6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3:0)Rd(7:4),Rd(7:4)Rd(3:0) None 1 BSET s Flag Set SREG(s)  1 SREG(s) 1 BCLR s Flag Clear SREG(s)  0 SREG(s) 1 BST Rr, b Bit Store from Register to T T  Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b)  T None 1 SEC Set Carry C  1 C1 CLC Clear Carry C  0 C 1 SEN Set Negative Flag N  1 N1 CLN Clear Negative Flag N  0 N 1 SEZ Set Zero Flag Z  1 Z1 CLZ Clear Zero Flag Z  0 Z 1 SEI Global Interrupt Enable I  1 I1 CLI Global Interrupt Disable I 0 I 1 SES Set Signed Test Flag S  1 S1 CLS Clear Signed Test Flag S  0 S 1 SEV Set Twos Complement Overflow. V  1 V1 CLV Clear Twos Complement Overflow V  0 V 1 SET Set T in SREG T  1 T1 Mnemonics Operands Description Operation Flags #Clocks CLT Clear T in SREG T  0 T 1 SEH Set Half Carry Flag in SREG H  1 H1 CLH Clear Half Carry Flag in SREG H  0 H 1 MCU CONTROL INSTRUCTIONS 31. Instruction Set Summary (Continued)ATmega8A [DATASHEET] 305 8159E–AVR–02/2013 NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/timer) None 1 31. Instruction Set Summary (Continued)ATmega8A [DATASHEET] 306 8159E–AVR–02/2013 32. Ordering Information Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging alternative, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. Tape & Reel 4. See characterization specifications at 105C Speed (MHz) Power Supply (V) Ordering Code(2) Package(1) Operation Range 16 2.7 - 5.5 ATmega8A-AU ATmega8A-AUR(3) ATmega8A-PU ATmega8A-MU ATmega8A-MUR(3) 32A 32A 28P3 32M1-A 32M1-A Industrial (-40C to 85C) ATmega8A-AN ATmega8A-ANR(3) ATmega8A-PN ATmega8A-MN ATmega8A-MNR(3) 32A 32A 28P3 32M1-A 32M1-A Extended (-40C to 105C)(4) Package Type 32A 32-lead, Thin (1.0mm) Plastic Quad Flat Package (TQFP) 28P3 28-lead, 0.300” Wide, Plastic Dual Inline Package (PDIP) 32M1-A 32-pad, 5 x 5 x 1.0 body, Lead Pitch 0.50 mm Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)ATmega8A [DATASHEET] 307 8159E–AVR–02/2013 33. Packaging Information 33.1 32A TITLE DRAWING NO. REV. 32A, 32-lead, 7 x 7mm body size, 1.0mm body thickness, 0.8mm lead pitch, thin profile plastic quad flat package (TQFP) 32A C 2010-10-20 PIN 1 IDENTIFIER 0°~7° PIN 1 L C A1 A2 A D1 D e E1 E B Notes: 1. This package conforms to JEDEC reference MS-026, Variation ABA. 2. Dimensions D1 and E1 do not include mold protrusion. Allowable protrusion is 0.25mm per side. Dimensions D1 and E1 are maximum plastic body size dimensions including mold mismatch. 3. Lead coplanarity is 0.10mm maximum. A – – 1.20 A1 0.05 – 0.15 A2 0.95 1.00 1.05 D 8.75 9.00 9.25 D1 6.90 7.00 7.10 Note 2 E 8.75 9.00 9.25 E1 6.90 7.00 7.10 Note 2 B 0.30 – 0.45 C 0.09 – 0.20 L 0.45 – 0.75 e 0.80 TYP COMMON DIMENSIONS (Unit of measure = mm) SYMBOL MIN NOM MAX NOTEATmega8A [DATASHEET] 308 8159E–AVR–02/2013 33.2 28P3 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 28P3, 28-lead (0.300"/7.62mm Wide) Plastic Dual Inline Package (PDIP) 28P3 B 09/28/01 PIN 1 E1 A1 B REF E B1 C L SEATING PLANE A 0º ~ 15º D e eB B2 (4 PLACES) COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A – – 4.5724 A1 0.508 – – D 34.544 – 34.798 Note 1 E 7.620 – 8.255 E1 7.112 – 7.493 Note 1 B 0.381 – 0.533 B1 1.143 – 1.397 B2 0.762 – 1.143 L 3.175 – 3.429 C 0.203 – 0.356 eB – – 10.160 e 2.540 TYP Note: 1. Dimensions D and E1 do not include mold Flash or Protrusion. Mold Flash or Protrusion shall not exceed 0.25mm (0.010"). ATmega8A [DATASHEET] 309 8159E–AVR–02/2013 32M1-A 34. Errata 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 32M1-A, 32-pad, 5 x 5 x 1.0mm Body, Lead Pitch 0.50mm, 32M1-A E 5/25/06 3.10mm Exposed Pad, Micro Lead Frame Package (MLF) COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE D1 D E1 E b e A3 A2 A1 A D2 E2 0.08 C L 1 2 3 P P 0 1 2 3 A 0.80 0.90 1.00 A1 – 0.02 0.05 A2 – 0.65 1.00 A3 0.20 REF b 0.18 0.23 0.30 D D1 D2 2.95 3.10 3.25 4.90 5.00 5.10 4.70 4.75 4.80 4.70 4.75 4.80 4.90 5.00 5.10 E E1 E2 2.95 3.10 3.25 e 0.50 BSC L 0.30 0.40 0.50 P – – 0.60 – – 12o Note: JEDEC Standard MO-220, Fig. 2 (Anvil Singulation), VHHD-2. TOP VIEW SIDE VIEW BOTTOM VIEW 0 Pin 1 ID Pin #1 Notch (0.20 R) K 0.20 – – K KATmega8A [DATASHEET] 310 8159E–AVR–02/2013 The revision letter in this section refers to the revision of the ATmega8A device. 34.1 ATmega8A, rev. L • First Analog Comparator conversion may be delayed • Interrupts may be lost when writing the timer registers in the asynchronous timer • Signature may be Erased in Serial Programming Mode • CKOPT Does not Enable Internal Capacitors on XTALn/TOSCn Pins when 32kHz Oscillator is Used to Clock the Asynchronous Timer/Counter2 • Reading EEPROM by using ST or STS to set EERE bit triggers unexpected interrupt request 1. First Analog Comparator conversion may be delayed If the device is powered by a slow rising VCC, the first Analog Comparator conversion will take longer than expected on some devices. Problem Fix / Workaround When the device has been powered or reset, disable then enable theAnalog Comparator before the first conversion. 2. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronous timer clock is written when the asynchronous Timer/Counter register (TCNTx) is 0x00. Problem Fix / Workaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx). 3. Signature may be Erased in Serial Programming Mode If the signature bytes are read before a chiperase command is completed, the signature may be erased causing the device ID and calibration bytes to disappear. This is critical, especially, if the part is running on internal RC oscillator. Problem Fix / Workaround: Ensure that the chiperase command has exceeded before applying the next command. 4. CKOPT Does not Enable Internal Capacitors on XTALn/TOSCn Pins when 32kHz Oscillator is Used to Clock the Asynchronous Timer/Counter2 When the internal RC Oscillator is used as the main clock source, it is possible to run the Timer/Counter2 asynchronously by connecting a 32kHz Oscillator between XTAL1/TOSC1 and XTAL2/TOSC2. But when the internal RC Oscillator is selected as the main clock source, the CKOPT Fuse does not control the internal capacitors on XTAL1/TOSC1 and XTAL2/TOSC2. As long as there are no capacitors connected to XTAL1/TOSC1 and XTAL2/TOSC2, safe operation of the Oscillator is not guaranteed. Problem Fix / Workaround Use external capacitors in the range of 20 - 36 pF on XTAL1/TOSC1 and XTAL2/TOSC2. This will be fixed in ATmega8A Rev. G where the CKOPT Fuse will control internal capacitors also when internal RC Oscillator is selected as main clock source. For ATmega8A Rev. G, CKOPT = 0 (programmed) will enable the internal capacitors on XTAL1 and XTAL2. Customers who want compatibility between Rev. G and older revisions, must ensure that CKOPT is unprogrammed (CKOPT = 1).ATmega8A [DATASHEET] 311 8159E–AVR–02/2013 5. Reading EEPROM by using ST or STS to set EERE bit triggers unexpected interrupt request. Reading EEPROM by using the ST or STS command to set the EERE bit in the EECR register triggers an unexpected EEPROM interrupt request. Problem Fix / Workaround Always use OUT or SBI to set EERE in EECR.ATmega8A [DATASHEET] 312 8159E–AVR–02/2013 35. Datasheet Revision History Please note that the referring page numbers in this section are referred to this document. The referring revision in this section refers to the document revision. 35.1 Rev.8159E – 02/2013 35.2 Rev.8159D – 02/11 35.3 Rev.8159C – 07/09 35.4 Rev.8159B – 05/09 1. Applied the Atmel new page layout for datasheets including new logo and last page. 2. Removed the reference to the debuggers and In-Circuit Emulators. 3. Added “Capacitive touch sensing” on page 6. 4. Added “Electrical Characteristics – TA = -40°C to 105°C” on page 233. 5. Added “Typical Characteristics – TA = -40°C to 105°C” on page 272. 1. Updated the datasheet according to the Atmel new Brand Style Guide. 2. Updated “Performing Page Erase by SPM” on page 200 by adding an extra note. 3. Updated “Ordering Information” on page 306 to include Tape & Reel. 1. Updated “Errata” on page 309. 1. Updated “System and Reset Characteristics” on page 228 with new BODLEVEL values 2. Updated “ADC Characteristics” on page 232 with new VINT values. 3. Updated “Typical Characteristics – TA = -40°C to 85°C” view. 4. Updated “Errata” on page 309. ATmega8A, rev L. 5. Created a new Table Of Contents.ATmega8A [DATASHEET] 313 8159E–AVR–02/2013 35.5 Rev.8159A – 08/08 1. Initial revision (Based on the ATmega8/L datasheet 2486T-AVR-05/08) 2. Changes done compared to ATmega8/L datasheet 2486T-AVR-05/08: – All Electrical Characteristics are moved to “Electrical Characteristics – TA = -40°C to 85°C” on page 225. – Updated “DC Characteristics” on page 225 with new VOL Max (0.9V and 0.6V) and typical value for ICC. – Added “Speed Grades” on page 227. – Added a new sub section “System and Reset Characteristics” on page 228. – Updated “System and Reset Characteristics” on page 228 with new VBOT BODLEVEL = 0 (3.6V, 4.0V and 4.2V). – Register descriptions are moved to sub section at the end of each chapter. – New graphics in “Typical Characteristics – TA = -40°C to 85°C” on page 235. – New “Ordering Information” on page 306.Enter Title of Manual [DATASHEET] i 8159E–AVR–02/2013 Table of Contents Features .....................................................................................................1 1 Pin Configurations ...................................................................................2 2 Overview ...................................................................................................3 2.1 Block Diagram ...................................................................................................3 2.2 Pin Descriptions .................................................................................................4 3 Resources .................................................................................................6 4 Data Retention ..........................................................................................6 5 About Code Examples .............................................................................6 6 Capacitive touch sensing ........................................................................6 7 AVR CPU Core ..........................................................................................7 7.1 Overview ............................................................................................................7 7.2 Arithmetic Logic Unit – ALU ...............................................................................8 7.3 Status Register ..................................................................................................8 7.4 General Purpose Register File ..........................................................................9 7.5 Stack Pointer ...................................................................................................10 7.6 Instruction Execution Timing ...........................................................................11 7.7 Reset and Interrupt Handling ...........................................................................12 8 AVR Memories ........................................................................................15 8.1 Overview ..........................................................................................................15 8.2 In-System Reprogrammable Flash Program Memory .....................................15 8.3 SRAM Data Memory ........................................................................................16 8.4 EEPROM Data Memory ..................................................................................17 8.5 I/O Memory ......................................................................................................17 8.6 Register Description ........................................................................................18 9 System Clock and Clock Options .........................................................24 9.1 Clock Systems and their Distribution ...............................................................24 9.2 Clock Sources .................................................................................................25 9.3 Crystal Oscillator .............................................................................................25 9.4 Low-frequency Crystal Oscillator .....................................................................27 9.5 External RC Oscillator .....................................................................................27 9.6 Calibrated Internal RC Oscillator .....................................................................29 9.7 External Clock .................................................................................................30Enter Title of Manual [DATASHEET] ii 8159E–AVR–02/2013 9.8 Timer/Counter Oscillator ..................................................................................30 9.9 Register Description ........................................................................................31 10 Power Management and Sleep Modes .................................................32 10.1 Sleep Modes ....................................................................................................32 10.2 Idle Mode .........................................................................................................32 10.3 ADC Noise Reduction Mode ............................................................................33 10.4 Power-down Mode ...........................................................................................33 10.5 Power-save Mode ............................................................................................33 10.6 Standby Mode .................................................................................................34 10.7 Minimizing Power Consumption ......................................................................34 10.8 Register Description ........................................................................................35 11 System Control and Reset .....................................................................36 11.1 Resetting the AVR ...........................................................................................36 11.2 Reset Sources .................................................................................................36 11.3 Internal Voltage Reference ..............................................................................39 11.4 Watchdog Timer ..............................................................................................40 11.5 Timed Sequences for Changing the Configuration of the Watchdog Timer ....40 11.6 Register Description ........................................................................................42 12 Interrupts .................................................................................................44 12.1 Interrupt Vectors in ATmega8A .......................................................................44 12.2 Register Description ........................................................................................47 13 I/O Ports ..................................................................................................49 13.1 Overview ..........................................................................................................49 13.2 Ports as General Digital I/O .............................................................................50 13.3 Alternate Port Functions ..................................................................................54 13.4 Register Description ........................................................................................62 14 External Interrupts .................................................................................64 14.1 Register Description ........................................................................................64 15 8-bit Timer/Counter0 ..............................................................................66 15.1 Features ..........................................................................................................66 15.2 Overview ..........................................................................................................66 15.3 Timer/Counter Clock Sources .........................................................................67 15.4 Counter Unit ....................................................................................................67 15.5 Operation .........................................................................................................67 15.6 Timer/Counter Timing Diagrams ......................................................................68Enter Title of Manual [DATASHEET] iii 8159E–AVR–02/2013 15.7 Register Description ........................................................................................69 16 Timer/Counter0 and Timer/Counter1 Prescalers .................................71 16.1 Overview ..........................................................................................................71 16.2 Internal Clock Source ......................................................................................71 16.3 Prescaler Reset ...............................................................................................71 16.4 External Clock Source .....................................................................................71 16.5 Register Description ........................................................................................72 17 16-bit Timer/Counter1 ............................................................................73 17.1 Features ..........................................................................................................73 17.2 Overview ..........................................................................................................73 17.3 Accessing 16-bit Registers ..............................................................................75 17.4 Timer/Counter Clock Sources .........................................................................78 17.5 Counter Unit ....................................................................................................78 17.6 Input Capture Unit ...........................................................................................79 17.7 Output Compare Units .....................................................................................81 17.8 Compare Match Output Unit ............................................................................83 17.9 Modes of Operation .........................................................................................84 17.10 Timer/Counter Timing Diagrams ......................................................................91 17.11 Register Description ........................................................................................92 18 8-bit Timer/Counter2 with PWM and Asynchronous Operation .........99 18.1 Features ..........................................................................................................99 18.2 Overview ..........................................................................................................99 18.3 Timer/Counter Clock Sources .......................................................................100 18.4 Counter Unit ..................................................................................................100 18.5 Output Compare Unit .....................................................................................101 18.6 Compare Match Output Unit ..........................................................................103 18.7 Modes of Operation .......................................................................................104 18.8 Timer/Counter Timing Diagrams ....................................................................108 18.9 Asynchronous Operation of the Timer/Counter .............................................109 18.10 Timer/Counter Prescaler ...............................................................................111 18.11 Register Description ......................................................................................112 19 Serial Peripheral Interface – SPI .........................................................116 19.1 Features ........................................................................................................116 19.2 Overview ........................................................................................................116 19.3 SS Pin Functionality ......................................................................................121Enter Title of Manual [DATASHEET] iv 8159E–AVR–02/2013 19.4 Data Modes ...................................................................................................121 19.5 Register Description ......................................................................................123 20 USART ...................................................................................................125 20.1 Features ........................................................................................................125 20.2 Overview ........................................................................................................125 20.3 Clock Generation ...........................................................................................127 20.4 Frame Formats ..............................................................................................129 20.5 USART Initialization .......................................................................................130 20.6 Data Transmission – The USART Transmitter ..............................................131 20.7 Asynchronous Data Reception ......................................................................138 20.8 Multi-processor Communication Mode ..........................................................141 20.9 Accessing UBRRH/UCSRC Registers ...........................................................142 20.10 Register Description ......................................................................................143 20.11 Examples of Baud Rate Setting .....................................................................147 21 Two-wire Serial Interface .....................................................................152 21.1 Features ........................................................................................................152 21.2 Overview ........................................................................................................152 21.3 Two-wire Serial Interface Bus Definition ........................................................154 21.4 Data Transfer and Frame Format ..................................................................155 21.5 Multi-master Bus Systems, Arbitration and Synchronization .........................157 21.6 Using the TWI ................................................................................................159 21.7 Multi-master Systems and Arbitration ............................................................174 21.8 Register Description ......................................................................................176 22 Analog Comparator ..............................................................................179 22.1 Overview ........................................................................................................179 22.2 Analog Comparator Multiplexed Input ...........................................................179 22.3 Register Description ......................................................................................180 23 Analog-to-Digital Converter ................................................................182 23.1 Features ........................................................................................................182 23.2 Overview ........................................................................................................182 23.3 Starting a Conversion ....................................................................................184 23.4 Prescaling and Conversion Timing ................................................................184 23.5 Changing Channel or Reference Selection ...................................................186 23.6 ADC Noise Canceler .....................................................................................187 23.7 ADC Conversion Result .................................................................................190Enter Title of Manual [DATASHEET] v 8159E–AVR–02/2013 23.8 Register Description ......................................................................................190 24 Boot Loader Support – Read-While-Write Self-Programming .........194 24.1 Features ........................................................................................................194 24.2 Overview ........................................................................................................194 24.3 Application and Boot Loader Flash Sections .................................................194 24.4 Read-While-Write and No Read-While-Write Flash Sections ........................194 24.5 Boot Loader Lock Bits ...................................................................................197 24.6 Entering the Boot Loader Program ................................................................198 24.7 Addressing the Flash During Self-Programming ...........................................198 24.8 Self-Programming the Flash ..........................................................................199 24.9 Register Description ......................................................................................205 25 Memory Programming .........................................................................207 25.1 Program And Data Memory Lock Bits ...........................................................207 25.2 Fuse Bits ........................................................................................................208 25.3 Signature Bytes .............................................................................................209 25.4 Calibration Byte .............................................................................................209 25.5 Page Size ......................................................................................................210 25.6 Parallel Programming Parameters, Pin Mapping, and Commands ...............210 25.7 Parallel Programming ....................................................................................212 25.8 Serial Downloading ........................................................................................220 25.9 Serial Programming Pin Mapping ..................................................................220 26 Electrical Characteristics – TA = -40°C to 85°C .................................225 26.1 Absolute Maximum Ratings* .........................................................................225 26.2 DC Characteristics .........................................................................................225 26.3 Speed Grades ...............................................................................................227 26.4 Clock Characteristics .....................................................................................227 26.5 System and Reset Characteristics ................................................................228 26.6 Two-wire Serial Interface Characteristics ......................................................229 26.7 SPI Timing Characteristics ............................................................................230 26.8 ADC Characteristics ......................................................................................232 27 Electrical Characteristics – TA = -40°C to 105°C ...............................233 27.1 DC Characteristics .........................................................................................233 28 Typical Characteristics – TA = -40°C to 85°C ....................................235 28.1 Active Supply Current ....................................................................................235 28.2 Idle Supply Current ........................................................................................239Enter Title of Manual [DATASHEET] vi 8159E–AVR–02/2013 28.3 Power-down Supply Current ..........................................................................242 28.4 Power-save Supply Current ...........................................................................243 28.5 Standby Supply Current ................................................................................244 28.6 Pin Pull-up .....................................................................................................247 28.7 Pin Driver Strength ........................................................................................249 28.8 Pin Thresholds and Hysteresis ......................................................................253 28.9 Bod Thresholds and Analog Comparator Offset ............................................258 28.10 Internal Oscillator Speed ...............................................................................260 28.11 Current Consumption of Peripheral Units ......................................................267 28.12 Current Consumption in Reset and Reset Pulsewidth ...................................270 29 Typical Characteristics – TA = -40°C to 105°C ..................................272 29.1 ATmega8A Typical Characteristics ................................................................272 30 Register Summary ................................................................................301 31 Instruction Set Summary .....................................................................303 32 Ordering Information ...........................................................................306 33 Packaging Information .........................................................................307 33.1 32A ................................................................................................................307 33.2 28P3 ..............................................................................................................308 34 Errata .....................................................................................................309 34.1 ATmega8A, rev. L ..........................................................................................310 35 Datasheet Revision History .................................................................312 35.1 Rev.8159E – 02/2013 ....................................................................................312 35.2 Rev.8159D – 02/11 ........................................................................................312 35.3 Rev.8159C – 07/09 ........................................................................................312 35.4 Rev.8159B – 05/09 ........................................................................................312 35.5 Rev.8159A – 08/08 ........................................................................................313 Table of Contents.......................................................................................iAtmel Corporation 1600 Technology Drive San Jose, CA 95110 USA Tel: (+1) (408) 441-0311 Fax: (+1) (408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Roa Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan G.K. 16F Shin-Osaki Kangyo Bldg 1-6-4 Osaki, Shinagawa-ku Tokyo 141-0032 JAPAN Tel: (+81) (3) 6417-0300 Fax: (+81) (3) 6417-0370 © 2013 Atmel Corporation. All rights reserved. / Rev.: 8159E–AVR–02/2013 Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. Atmel®, Atmel logo and combinations thereof, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Atmel AVR1924: XMEGA-A1 Xplained Hardware User's Guide Features • Atmel® ATxmega128A1 microcontroller • External memory - 8MB SDRAM • Atmel AT32UC3B1256 - Communication gateway - Programmer for Atmel AVR® XMEGA® • Analog input (to ADC) - Temperature sensor - Light sensor • Analog output (from DAC) - Mono speaker via audio amplifier • Digital I/O - UART communication through USB gateway - Eight mechanical button switches - Eight LEDs - Eight spare analog pins - 24 spare digital pins 1 Introduction The Atmel XMEGA-A1 Xplained evaluation kit is a hardware platform to evaluate the Atmel ATxmega128A1 microcontroller. The kit offers a larger range of features that enables the Atmel AVR XMEGA user to get started using XMEGA peripherals right away and understand how to integrate the XMEGA device in their own design. Figure 1-1. XMEGA-A1 Xplained evaluation kit. 8-bit Atmel Microcontrollers Application Note Preliminary Rev. 8370C-AVR-12/11 2 Atmel AVR1924 8370C-AVR-12/11 2 Related items Atmel FLIP (Flexible In-system Programmer) http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3886 Atmel AVR Studio® 4 (free Atmel IDE) http://www.atmel.com/dyn/products/tools_card.asp?tool_id=2725 Atmel AVR JTAGICE mkII (on-chip programming and debugging tool) http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3353 Atmel AVR ONE! (on-chip programming and debugging tool) http://www.atmel.com/dyn/products/tools_card.asp?tool_id=4279 3 General information This document targets the Atmel XMEGA-A1 Xplained evaluation kit, revision 9. The schematic, layout, and bill of materials can be found online in the zip files associated with this application note at: http://www.atmel.com/products/AVR/xplain.asp?family_id=607&source=redirect. The XMEGA-A1 Xplained kit is intended to demonstrate the Atmel ATxmega128A1 microcontroller, and the hardware that relates to the Atmel AT32UC3B1256 is, therefore, not covered in this document. Figure 3-1. Overview of the XMEGA-A1 Xplained kit. SDRAM ATxmega128A1 JTAG and PDI DataFlash footprint XMEGA PORT A USB (COM and PSU) ATxmega128A1 Speaker XMEGA PORT C Audio amp. XMEGA PORT F Power jumper XMEGA PORT D/R Light sensor Temp. sensor AT32UC3B1256 3.1 Preprogrammed firmware The Atmel ATxmega128A1 and AT32UC3B1256 that come with the Atmel XMEGAA1 Xplained kit are both preprogrammed. The preprogrammed firmware in the XMEGA plays different sounds when the mechanical button switches are pushed. Atmel AVR1924 3 8370C-AVR-12/11 The preprogrammed Atmel AT32UC3B1256 firmware offers features such as a boot loader for self-programming and a UART-to-USB gateway. 3.2 Power supply The kit is powered via the USB connector, which leaves two options to power it: Connect the kit either to a PC through a USB cable, or to a 5V USB power supply (AC/DC adapter). 3.3 Measuring the XMEGA power consumption As part of an evaluation of the Atmel ATxmega128A1, it can be of interest to measure its power consumption. The power jumper (J300) is connected between the 3.3V regulated voltage from the regulator and the ATxmega128A1 supply. By replacing the jumper with an ammeter, it is possible to measure the current consumption of the ATxmega128A1. No other components are connected to the same supply as the ATxmega128A1, and other components, therefore, do not affect the measurement of the ATxmega128A1 current consumption (except the DC leakage in the decoupling capacitors). 3.4 Programming the XMEGA through the UART-to-USB gateway The ATxmega128A1 has a pre-programmed UART boot loader. How to program the device through the UART-to-USB gateway is described in the Atmel application note “AVR1927: XMEGA-A1 Xplained Getting started guide”. 3.5 Communication through the UART-to-USB gateway The XMEGA UARTC0 is connected to a UART on the AT32UC3B1256. The AT32UC3B1256 UART is communicating at 115200 baud, using one start bit, eight data bits, one stop bit, and no parity. When the AT32UC3B1256 device is enumerated (connected to a PC), the data transmitted from the XMEGA is passed on to a (virtual) COM port. This means that it is possible to use a terminal program to receive the transmitted data on a PC. Similarly, data transmitted from the PC COM port is passed on to the XMEGA UART through the gateway. NOTE The AT32UC3B1256 is also connected to the shared SPI and TWI lines, and so it is also possible to add TWI and SPI gateway functionality for these serial interfaces, if desired. This gateway functionality is not available in the default firmware for the AT32UC3B1256. Please refer to the schematics for more information about these connections. 4 Atmel AVR1924 8370C-AVR-12/11 4 Connectors The Atmel XMEGA-A1 Xplained kit has five 10-pin, 100mil headers. One header is used for programming the Atmel ATxmega128A1, and the others are used to access spare analog and digital pins on the XMEGA (expansion headers). 4.1 Programming headers The XMEGA can be programmed and debugged by connecting an external programming/debugging tool to the JTAG and PDI header (J201). The header has a standard JTAG programmer pin-out (refer to online help in the Atmel AVR Studio), and tools like the JTAGICE mkII or AVR ONE! can thus be connected directly to the header. If it is desired to use PDI programming/debugging, an adapter must be used. Due to physical differences of the JTAGICE mkII and AVR ONE! probes, the PCB has an opening below the JTAG and PDI header. This is to make room for the orientation tap on the JTAGICE mkII probe. Because JTAG TDO and PDI DATA are connected on the PCB for this kit, JTAG must be disabled on the device in order to use PDI. The reason for this is that when JTAG is enabled it will enable a pull-up internally on TDO which interferes with the PDI initialization sequence. The connection of JTAG_TDO with PDI_DATA is also an issue when the application on the device uses the JTAG_TDO pin e.g. by driving this pin actively or by using a pull-up. This will interfere with ongoing PDI communication. Additionally, when JTAG is disabled and the application is driving the JTAG_TDO pin it might even be not possible to establish a PDI connection. A workaround for this is to add a ~1k resistor from PDI_CLK/RESET to GND. This will keep the device in reset while PDI is enabled. When a PDI connection is established the flash can be erased or JTAG can be enabled in order to "unlock" the kit. Table 4-1. XMEGA programming and debugging interface – JTAG and PDI. J201 pin JTAG (1) PDI (2) 1 TCK - 2 GND GND (3) 3 TDO DATA 4 VCC VCC (3) 5 TMS - 6 nSRST CLK 7 - - 8 - - 9 TDI - 10 GND GND (3) Notes: 1. Standard pin-out for JTAGICE mkII and other Atmel programming tools. 2. Requires adapter to connect a JTAGICE mkII (refer to AVR Studio help). 3. It is only required to connect on VCC/GND pin. The Atmel AT32UC3B1256 can be programmed through its boot loader. The boot loader is evoked by shorting the J600 jumper before applying power to the board. The Atmel AVR1924 5 8370C-AVR-12/11 programming is performed through the FLIP plug-in in AVR Studio (which can also be started as a standalone application). FLIP (Flexible In-system Programmer) is free Atmel proprietary software that runs on Windows® 9x/Me/NT/2000/XP and Linux® x86. FLIP supports in-system programming of flash devices through RS232, USB, or CAN. Alternatively, the AT32UC3B1256 can be programmed by connecting a programming tool, such as JTAGICE mkII, to test points TP600-607. NOTE It is not recommended to program the AT32UC3B1256 using a programming tool, as this will erase the boot loader. 4.2 I/O expansion headers The XMEGA analog PORTA is available on the J2 header. This allows the user to connect external signals to the analog-to-digital converter (ADC), digital-to-analog converter (DAC), and analog comparators on PORTA. The XMEGA digital PORTF and PORTC are available on the J1 and J4 headers, respectively. These ports feature general-purpose I/O and various communication modules (USART, SPI, and TWI). PORTD and PORTF are mixed on the J3 header. NOTE The communication modules on PORTC and PORTF can be interconnected to test various functions and features: The USART can loop back communication with a jumper, or communicate between the two USARTs on the port. The native SPI and the USART in SPI master mode can be connected, and the TWI module can be enabled in both master and slave modes at the same time to get loop-back behavior. (Pull-up resistors can be mounted on R101 and R102. These are not mounted from the factory.) 6 Atmel AVR1924 8370C-AVR-12/11 5 Attached memories The Atmel XMEGA-A1 Xplained kit demonstrates how to use the external bus interface (EBI) module to connect a 4-bit SDRAM. An 8MB SDRAM (16Mb x 4) is attached in three-port EBI mode (PORTH, PORTK, and PORTJ). Atmel AVR1924 7 8370C-AVR-12/11 6 Miscellaneous I/O 6.1 Mechanical button switches Eight mechanical button switches are connected to XMEGA PORTD(PD0:PD5) and PORTR(PR0:PR1). Internal pull-ups should be enabled to detect when the buttons are pushed, as they short the respective line to GND. NOTE Buttons share the pins with the J3 header: Pushing the buttons potentially affects communication or other functionality on these pins. 6.2 LEDs Eight yellow LEDs are connected to XMEGA PORTE. The LEDs are active low, and thus light up when the respective lines are output low by the XMEGA. One green and one red LED are inside the same package and therefore the colors can be mixed to orange when both are activated. The red LED can be activated by driving the connected I/O line to GND. The green LED is controlled via a FET and is by default on when the board is powered. However this power indicator LED can also be turned off by driving the gate of the FET to GND. Both LEDs are controlled by the Atmel AT32UC3B1256. The default firmware will use the red LED to signal activity on the UART to USB bridge by toggling the LED. 6.3 Analog I/O An NTC temperature sensor and a light sensor are connected to PORTB on PB0 and PB1, respectively. These analog references can be used as input to the ADC. An audio amplifier (and mono speaker) is connected to PORTB on pin PB2. This pin is connected to the XMEGA DAC, and thus offers a way to generate sound. 8 Atmel AVR1924 8370C-AVR-12/11 7 Included code example The example application is based on the Atmel AVR Software Framework found online at http://asf.atmel.no. For documentation, help, and examples on the drivers used, please see the website. For more information about the included code example, see the Atmel application note “AVR1927: XMEGA-A1 Xplained Getting Started Guide”. 7.1 Compiling and running The code examples to be found in ASF can be compiled by running make on the makefile included in the project, or by opening the project in IAR™, and compiling the project within IAR. Atmel AVR1924 9 8370C-AVR-12/11 8 Further code examples and drivers Several Getting-Started trainings for the Atmel XMEGA-A1 Xplained kit can be downloaded from the Atmel website. These trainings offer general introduction to XMEGA peripherals. Please refer to AVR1500 through AVR1510. Further information and drivers for XMEGA can be downloaded as application notes, also distributed from the Atmel website. 10 Atmel AVR1924 8370C-AVR-12/11 9 Known issues 9.1 Light sensor The output range of the light sensor is 0V – 3.3V. The ADC reference must therefore be high enough to match the output range of the light sensor when performing measurements. 9.2 USB test points Touching the test points of the USB data lines on the reverse side of the board while there is an ongoing communication, might interrupt the device and cause the device to stop responding. The kit must be reconnected to start working properly again. 9.3 PDI initialization Because JTAG_TDO and PDI_DATA are connected on the PCB for this kit, JTAG must be disabled on the device in order to use PDI. The reason for this is that when JTAG is enabled it will enable a pull-up internally on TDO which interferes with the PDI initialization sequence. The connection of JTAG_TDO with PDI_DATA is also an issue when the application on the device uses the JTAG_TDO pin e.g. by driving this pin actively or by using a pull-up. This will interfere with ongoing PDI communication. Additionally, when JTAG is disabled and the application is driving the JTAG_TDO pin it might even not be possible to establish a PDI connection. A workaround for this is to add a ~1k resistor from PDI_CLK/RESET to GND. This will keep the device in reset while PDI is enabled. When a PDI connection is established the flash can be erased or JTAG can be enabled in order to "unlock" the kit. Atmel AVR1924 11 8370C-AVR-12/11 10 Revision history The revision of the evaluation kit can be found on the sticker on the reverse side of the PCB. 10.1 Revision 7 The Atmel XMEGA-A1 Xplained kit, revision 7, is the first released revision of the XMEGA-A1 Xplained kit. This kit replaces the Atmel Xplain evaluation kit. Information about the original Xplain evaluation kit can be found in the Atmel application note AVR1907: Xplain Hardware User’s Guide. 10.2 Revisions 1 to 6 Not released. 12 Atmel AVR1924 8370C-AVR-12/11 11 Table of contents Features............................................................................................... 1 1 Introduction...................................................................................... 1 2 Related items.................................................................................... 2 3 General information......................................................................... 2 3.1 Preprogrammed firmware.................................................................................... 2 3.2 Power supply....................................................................................................... 3 3.3 Measuring the XMEGA power consumption ....................................................... 3 3.4 Programming the XMEGA through the UART-to-USB gateway ......................... 3 3.5 Communication through the UART-to-USB gateway.......................................... 3 4 Connectors....................................................................................... 4 4.1 Programming headers......................................................................................... 4 4.2 I/O expansion headers ........................................................................................ 5 5 Attached memories.......................................................................... 6 6 Miscellaneous I/O............................................................................. 7 6.1 Mechanical button switches ................................................................................ 7 6.2 LEDs.................................................................................................................... 7 6.3 Analog I/O............................................................................................................ 7 7 Included code example ................................................................... 8 7.1 Compiling and running ........................................................................................ 8 8 Further code examples and drivers ............................................... 9 9 Known issues................................................................................. 10 9.1 Light sensor....................................................................................................... 10 9.2 USB test points.................................................................................................. 10 9.3 PDI initialization................................................................................................. 10 10 Revision history ........................................................................... 11 10.1 Revision 7........................................................................................................ 11 10.2 Revisions 1 to 6............................................................................................... 11 11 Table of contents ......................................................................... 128370C-AVR-12/11 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: (+1)(408) 441-0311 Fax: (+1)(408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Milennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan 16F, Shin Osaki Kangyo Bldg. 1-6-4 Osaki Shinagawa-ku Tokyo 104-0032 JAPAN Tel: (+81) 3-6417-0300 Fax: (+81) 3-6417-0370 © 2011 Atmel Corporation. All rights reserved. Atmel® , Atmel logo and combinations thereof, AVR® , AVR Logo® , AVR Studio® , XMEGA® and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Windows® and others are registered trademarks of Microsoft Corporation in U.S. and or other countries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice. 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Features • High-performance, Low-power Atmel®AVR® 8-bit Microcontroller • Advanced RISC Architecture – 130 Powerful Instructions – Most Single-clock Cycle Execution – 32 × 8 General Purpose Working Registers – Fully Static Operation – Up to 16MIPS Throughput at 16MHz – On-chip 2-cycle Multiplier • High Endurance Non-volatile Memory segments – 8Kbytes of In-System Self-programmable Flash program memory – 512Bytes EEPROM – 1Kbyte Internal SRAM – Write/Erase Cycles: 10,000 Flash/100,000 EEPROM – Data retention: 20 years at 85°C/100 years at 25°C(1) – Optional Boot Code Section with Independent Lock Bits In-System Programming by On-chip Boot Program True Read-While-Write Operation – Programming Lock for Software Security • Peripheral Features – Two 8-bit Timer/Counters with Separate Prescaler, one Compare Mode – One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode – Real Time Counter with Separate Oscillator – Three PWM Channels – 8-channel ADC in TQFP and QFN/MLF package Eight Channels 10-bit Accuracy – 6-channel ADC in PDIP package Six Channels 10-bit Accuracy – Byte-oriented Two-wire Serial Interface – Programmable Serial USART – Master/Slave SPI Serial Interface – Programmable Watchdog Timer with Separate On-chip Oscillator – On-chip Analog Comparator • Special Microcontroller Features – Power-on Reset and Programmable Brown-out Detection – Internal Calibrated RC Oscillator – External and Internal Interrupt Sources – Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, and Standby • I/O and Packages – 23 Programmable I/O Lines – 28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF • Operating Voltages – 2.7V - 5.5V (ATmega8L) – 4.5V - 5.5V (ATmega8) • Speed Grades – 0 - 8MHz (ATmega8L) – 0 - 16MHz (ATmega8) • Power Consumption at 4Mhz, 3V, 25C – Active: 3.6mA – Idle Mode: 1.0mA – Power-down Mode: 0.5µA 8-bit Atmel with 8KBytes InSystem Programmable Flash ATmega8 ATmega8L Rev.2486AA–AVR–02/20132 2486AA–AVR–02/2013 ATmega8(L) Pin Configurations 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 (INT1) PD3 (XCK/T0) PD4 GND VCC GND VCC (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 PC1 (ADC1) PC0 (ADC0) ADC7 GND AREF ADC6 AVCC PB5 (SCK) 32 31 30 29 28 27 26 25 9 10 11 12 13 14 15 16 (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 (OC1A) PB1 (SS/OC1B) PB2 (MOSI/OC2) PB3 (MISO) PB4 PD2 (INT0) PD1 (TXD) PD0 (RXD) PC6 (RESET) PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) TQFP Top View 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 (RESET) PC6 (RXD) PD0 (TXD) PD1 (INT0) PD2 (INT1) PD3 (XCK/T0) PD4 VCC GND (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) PC1 (ADC1) PC0 (ADC0) GND AREF AVCC PB5 (SCK) PB4 (MISO) PB3 (MOSI/OC2) PB2 (SS/OC1B) PB1 (OC1A) PDIP 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 32 31 30 29 28 27 26 25 9 10 11 12 13 14 15 16 MLF Top View (INT1) PD3 (XCK/T0) PD4 GND VCC GND VCC (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 PC1 (ADC1) PC0 (ADC0) ADC7 GND AREF ADC6 AVCC PB5 (SCK) (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 (OC1A) PB1 (SS/OC1B) PB2 (MOSI/OC2) PB3 (MISO) PB4 PD2 (INT0) PD1 (TXD) PD0 (RXD) PC6 (RESET) PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) NOTE: The large center pad underneath the MLF packages is made of metal and internally connected to GND. It should be soldered or glued to the PCB to ensure good mechanical stability. If the center pad is left unconneted, the package might loosen from the PCB.3 2486AA–AVR–02/2013 ATmega8(L) Overview The Atmel®AVR® ATmega8 is a low-power CMOS 8-bit microcontroller based on the AVR RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega8 achieves throughputs approaching 1MIPS per MHz, allowing the system designer to optimize power consumption versus processing speed. Block Diagram Figure 1. Block Diagram INTERNAL OSCILLATOR OSCILLATOR WATCHDOG TIMER MCU CTRL. & TIMING OSCILLATOR TIMERS/ COUNTERS INTERRUPT UNIT STACK POINTER EEPROM SRAM STATUS REGISTER USART PROGRAM COUNTER PROGRAM FLASH INSTRUCTION REGISTER INSTRUCTION DECODER PROGRAMMING LOGIC SPI ADC INTERFACE COMP. INTERFACE PORTC DRIVERS/BUFFERS PORTC DIGITAL INTERFACE GENERAL PURPOSE REGISTERS X Y Z ALU + - PORTB DRIVERS/BUFFERS PORTB DIGITAL INTERFACE PORTD DIGITAL INTERFACE PORTD DRIVERS/BUFFERS XTAL1 XTAL2 CONTROL LINES VCC GND MUX & ADC AGND AREF PC0 - PC6 PB0 - PB7 PD0 - PD7 AVR CPU TWI RESET4 2486AA–AVR–02/2013 ATmega8(L) The Atmel®AVR® core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The ATmega8 provides the following features: 8 Kbytes of In-System Programmable Flash with Read-While-Write capabilities, 512 bytes of EEPROM, 1 Kbyte of SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with compare modes, internal and external interrupts, a serial programmable USART, a byte oriented Twowire Serial Interface, a 6-channel ADC (eight channels in TQFP and QFN/MLF packages) with 10-bit accuracy, a programmable Watchdog Timer with Internal Oscillator, an SPI serial port, and five software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue functioning. The Powerdown mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next Interrupt or Hardware Reset. In Power-save mode, the asynchronous timer continues to run, allowing the user to maintain a timer base while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules except asynchronous timer and ADC, to minimize switching noise during ADC conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low-power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The Flash Program memory can be reprogrammed In-System through an SPI serial interface, by a conventional non-volatile memory programmer, or by an On-chip boot program running on the AVR core. The boot program can use any interface to download the application program in the Application Flash memory. Software in the Boot Flash Section will continue to run while the Application Flash Section is updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the Atmel ATmega8 is a powerful microcontroller that provides a highly-flexible and cost-effective solution to many embedded control applications. The ATmega8 is supported with a full suite of program and system development tools, including C compilers, macro assemblers, program simulators, and evaluation kits. Disclaimer Typical values contained in this datasheet are based on simulations and characterization of other AVR microcontrollers manufactured on the same process technology. Minimum and Maximum values will be available after the device is characterized.5 2486AA–AVR–02/2013 ATmega8(L) Pin Descriptions VCC Digital supply voltage. GND Ground. Port B (PB7..PB0) XTAL1/XTAL2/TOSC1/ TOSC2 Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Depending on the clock selection fuse settings, PB6 can be used as input to the inverting Oscillator amplifier and input to the internal clock operating circuit. Depending on the clock selection fuse settings, PB7 can be used as output from the inverting Oscillator amplifier. If the Internal Calibrated RC Oscillator is used as chip clock source, PB7..6 is used as TOSC2..1 input for the Asynchronous Timer/Counter2 if the AS2 bit in ASSR is set. The various special features of Port B are elaborated in “Alternate Functions of Port B” on page 58 and “System Clock and Clock Options” on page 25. Port C (PC5..PC0) Port C is an 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port C output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running. PC6/RESET If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical characteristics of PC6 differ from those of the other pins of Port C. If the RSTDISBL Fuse is unprogrammed, PC6 is used as a Reset input. A low level on this pin for longer than the minimum pulse length will generate a Reset, even if the clock is not running. The minimum pulse length is given in Table 15 on page 38. Shorter pulses are not guaranteed to generate a Reset. The various special features of Port C are elaborated on page 61. Port D (PD7..PD0) Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port D also serves the functions of various special features of the ATmega8 as listed on page 63. RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running. The minimum pulse length is given in Table 15 on page 38. Shorter pulses are not guaranteed to generate a reset.6 2486AA–AVR–02/2013 ATmega8(L) AVCC AVCC is the supply voltage pin for the A/D Converter, Port C (3..0), and ADC (7..6). It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. Note that Port C (5..4) use digital supply voltage, VCC. AREF AREF is the analog reference pin for the A/D Converter. ADC7..6 (TQFP and QFN/MLF Package Only) In the TQFP and QFN/MLF package, ADC7..6 serve as analog inputs to the A/D converter. These pins are powered from the analog supply and serve as 10-bit ADC channels.7 2486AA–AVR–02/2013 ATmega8(L) Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. Note: 1. Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C.8 2486AA–AVR–02/2013 ATmega8(L) About Code Examples This datasheet contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details.9 2486AA–AVR–02/2013 ATmega8(L) Atmel AVR CPU Core Introduction This section discusses the Atmel®AVR® core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. Architectural Overview Figure 2. Block Diagram of the AVR MCU Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the Program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the Program memory. This concept enables instructions to be executed in every clock cycle. The Program memory is In-System Reprogrammable Flash memory. The fast-access Register File contains 32 × 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers Flash Program Memory Instruction Register Instruction Decoder Program Counter Control Lines 32 x 8 General Purpose Registrers ALU Status and Control I/O Lines EEPROM Data Bus 8-bit Data SRAM Direct Addressing Indirect Addressing Interrupt Unit SPI Unit Watchdog Timer Analog Comparator i/O Module 2 i/O Module1 i/O Module n10 2486AA–AVR–02/2013 ATmega8(L) can also be used as an address pointer for look up tables in Flash Program memory. These added function registers are the 16-bit X-register, Y-register, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. The Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every Program memory address contains a 16-bit or 32-bit instruction. Program Flash memory space is divided in two sections, the Boot program section and the Application program section. Both sections have dedicated Lock Bits for write and read/write protection. The SPM instruction that writes into the Application Flash memory section must reside in the Boot program section. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the reset routine (before subroutines or interrupts are executed). The Stack Pointer SP is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional global interrupt enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O Memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F.11 2486AA–AVR–02/2013 ATmega8(L) Arithmetic Logic Unit – ALU The high-performance Atmel®AVR® ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. For a detailed description, see “Instruction Set Summary” on page 311. Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software. The AVR Status Register – SREG – is defined as: • Bit 7 – I: Global Interrupt Enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the Instruction Set Reference. • Bit 6 – T: Bit Copy Storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half Carry Flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry is useful in BCD arithmetic. See the “Instruction Set Description” for detailed information. • Bit 4 – S: Sign Bit, S = N V The S-bit is always an exclusive or between the Negative Flag N and the Two’s Complement Overflow Flag V. See the “Instruction Set Description” for detailed information. • Bit 3 – V: Two’s Complement Overflow Flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See the “Instruction Set Description” for detailed information. • Bit 2 – N: Negative Flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. Bit 7 6 5 4 3 2 1 0 I T H S V N Z C SREG Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 012 2486AA–AVR–02/2013 ATmega8(L) • Bit 1 – Z: Zero Flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 0 – C: Carry Flag The Carry Flag C indicates a Carry in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. General Purpose Register File The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 3 shows the structure of the 32 general purpose working registers in the CPU. Figure 3. AVR CPU General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 3, each register is also assigned a Data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-pointer, Y-pointer, and Z-pointer Registers can be set to index any register in the file. 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E Purpose R15 0x0F Working R16 0x10 Registers R17 0x11 … R26 0x1A X-register Low Byte R27 0x1B X-register High Byte R28 0x1C Y-register Low Byte R29 0x1D Y-register High Byte R30 0x1E Z-register Low Byte R31 0x1F Z-register High Byte13 2486AA–AVR–02/2013 ATmega8(L) The X-register, Yregister and Z-register The registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the Data Space. The three indirect address registers X, Y and Z are defined as described in Figure 4. Figure 4. The X-register, Y-register and Z-Register In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the Instruction Set Reference for details). Stack Pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x60. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when address is popped from the Stack with return from subroutine RET or return from interrupt RETI. The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The Atmel®AVR® CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. 15 XH XL 0 X-register 7 0 7 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 0 7 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 7 0 7 0 R31 (0x1F) R30 (0x1E) Bit 15 14 13 12 11 10 9 8 SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 SPH SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL 76543210 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 0000000014 2486AA–AVR–02/2013 ATmega8(L) Figure 5 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access Register File concept. This is the basic pipelining concept to obtain up to 1MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. Figure 5. The Parallel Instruction Fetches and Instruction Executions Figure 6 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 6. Single Cycle ALU Operation Reset and Interrupt Handling The Atmel®AVR® provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate Program Vector in the Program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. Depending on the Program Counter value, interrupts may be automatically disabled when Boot Lock Bits BLB02 or BLB12 are programmed. This feature improves software security. See the section “Memory Programming” on page 215 for details. The lowest addresses in the Program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of Vectors is shown in “Interrupts” on page 46. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. The Interrupt Vectors can be moved to the start of the boot Flash section by setting the Interrupt Vector Select (IVSEL) bit in the General Interrupt Control Register (GICR). Refer to “Interrupts” on page 46 for more information. The Reset Vector can also be moved to the start of the boot Flash section by programming the BOOTRST Fuse, see “Boot Loader Support – ReadWhile-Write Self-Programming” on page 202. clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPU Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPU15 2486AA–AVR–02/2013 ATmega8(L) When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the global interrupt enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the global interrupt enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence. Assembly Code Example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMWE ; start EEPROM write sbi EECR, EEWE out SREG, r16 ; restore SREG value (I-bit) C Code Example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ _CLI(); EECR |= (1< xxx ... ... ... Table 19. Reset and Interrupt Vectors Placement BOOTRST(1) IVSEL Reset Address Interrupt Vectors Start Address 1 0 0x000 0x001 1 1 0x000 Boot Reset Address + 0x001 0 0 Boot Reset Address 0x001 0 1 Boot Reset Address Boot Reset Address + 0x00148 2486AA–AVR–02/2013 ATmega8(L) When the BOOTRST Fuse is unprogrammed, the boot section size set to 2Kbytes and the IVSEL bit in the GICR Register is set before any interrupts are enabled, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: AddressLabels Code Comments $000 rjmp RESET ; Reset handler ; $001 RESET:ldi r16,high(RAMEND); Main program start $002 out SPH,r16 ; Set Stack Pointer to top of RAM $003 ldi r16,low(RAMEND) $004 out SPL,r16 $005 sei ; Enable interrupts $006 xxx ; .org $c01 $c01 rjmp EXT_INT0 ; IRQ0 Handler $c02 rjmp EXT_INT1 ; IRQ1 Handler ... ... ... ; $c12 rjmp SPM_RDY ; Store Program Memory Ready Handler When the BOOTRST Fuse is programmed and the boot section size set to 2Kbytes, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: AddressLabels Code Comments .org $001 $001 rjmp EXT_INT0 ; IRQ0 Handler $002 rjmp EXT_INT1 ; IRQ1 Handler ... ... ... ; $012 rjmp SPM_RDY ; Store Program Memory Ready Handler ; .org $c00 $c00 rjmp RESET ; Reset handler ; $c01 RESET:ldi r16,high(RAMEND); Main program start $c02 out SPH,r16 ; Set Stack Pointer to top of RAM $c03 ldi r16,low(RAMEND) $c04 out SPL,r16 $c05 sei ; Enable interrupts $c06 xxx49 2486AA–AVR–02/2013 ATmega8(L) When the BOOTRST Fuse is programmed, the boot section size set to 2Kbytes, and the IVSEL bit in the GICR Register is set before any interrupts are enabled, the most typical and general program setup for the Reset and Interrupt Vector Addresses is: AddressLabels Code Comments ; .org $c00 $c00 rjmp RESET ; Reset handler $c01 rjmp EXT_INT0 ; IRQ0 Handler $c02 rjmp EXT_INT1 ; IRQ1 Handler ... ... ... ; $c12 rjmp SPM_RDY ; Store Program Memory Ready Handler $c13 RESET: ldi r16,high(RAMEND); Main program start $c14 out SPH,r16 ; Set Stack Pointer to top of RAM $c15 ldi r16,low(RAMEND) $c16 out SPL,r16 $c17 sei ; Enable interrupts $c18 xxx Moving Interrupts Between Application and Boot Space The General Interrupt Control Register controls the placement of the Interrupt Vector table. General Interrupt Control Register – GICR • Bit 1 – IVSEL: Interrupt Vector Select When the IVSEL bit is cleared (zero), the Interrupt Vectors are placed at the start of the Flash memory. When this bit is set (one), the Interrupt Vectors are moved to the beginning of the Boot Loader section of the Flash. The actual address of the start of the boot Flash section is determined by the BOOTSZ Fuses. Refer to the section “Boot Loader Support – Read-While-Write Self-Programming” on page 202 for details. To avoid unintentional changes of Interrupt Vector tables, a special write procedure must be followed to change the IVSEL bit: 1. Write the Interrupt Vector Change Enable (IVCE) bit to one 2. Within four cycles, write the desired value to IVSEL while writing a zero to IVCE Interrupts will automatically be disabled while this sequence is executed. Interrupts are disabled in the cycle IVCE is set, and they remain disabled until after the instruction following the write to IVSEL. If IVSEL is not written, interrupts remain disabled for four cycles. The I-bit in the Status Register is unaffected by the automatic disabling. Note: If Interrupt Vectors are placed in the Boot Loader section and Boot Lock bit BLB02 is programmed, interrupts are disabled while executing from the Application section. If Interrupt Vectors are placed in the Application section and Boot Lock bit BLB12 is programed, interrupts are disabled while executing from the Boot Loader section. Refer to the section “Boot Loader Support – Read-While-Write Self-Programming” on page 202 for details on Boot Lock Bits. Bit 7 6 5 4 3 2 1 0 INT1 INT0 – – – – IVSEL IVCE GICR Read/Write R/W R/W R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 050 2486AA–AVR–02/2013 ATmega8(L) • Bit 0 – IVCE: Interrupt Vector Change Enable The IVCE bit must be written to logic one to enable change of the IVSEL bit. IVCE is cleared by hardware four cycles after it is written or when IVSEL is written. Setting the IVCE bit will disable interrupts, as explained in the IVSEL description above. See Code Example below. Assembly Code Example Move_interrupts: ; Enable change of Interrupt Vectors ldi r16, (1< CSn2:0 > 1). The number of system clock cycles from when the timer is enabled to the first count occurs can be from 1 to N+1 system clock cycles, where N equals the prescaler divisor (8, 64, 256, or 1024). It is possible to use the prescaler reset for synchronizing the Timer/Counter to program execution. However, care must be taken if the other Timer/Counter that shares the same prescaler also uses prescaling. A prescaler reset will affect the prescaler period for all Timer/Counters it is connected to. External Clock Source An external clock source applied to the T1/T0 pin can be used as Timer/Counter clock (clkT1/clkT0). The T1/T0 pin is sampled once every system clock cycle by the pin synchronization logic. The synchronized (sampled) signal is then passed through the edge detector. Figure 30 shows a functional equivalent block diagram of the T1/T0 synchronization and edge detector logic. The registers are clocked at the positive edge of the internal system clock (clkI/O). The latch is transparent in the high period of the internal system clock. The edge detector generates one clkT1/clkT0 pulse for each positive (CSn2:0 = 7) or negative (CSn2:0 = 6) edge it detects. Figure 30. T1/T0 Pin Sampling The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles from an edge has been applied to the T1/T0 pin to the counter is updated. Enabling and disabling of the clock input must be done when T1/T0 has been stable for at least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated. Each half period of the external clock applied must be longer than one system clock cycle to ensure correct sampling. The external clock must be guaranteed to have less than half the system clock frequency (fExtClk < fclk_I/O/2) given a 50/50% duty cycle. Since the edge detector uses Tn_sync (To Clock Select Logic) Synchronization Edge Detector D Q D Q LE Tn D Q clkI/O74 2486AA–AVR–02/2013 ATmega8(L) sampling, the maximum frequency of an external clock it can detect is half the sampling frequency (Nyquist sampling theorem). However, due to variation of the system clock frequency and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is recommended that maximum frequency of an external clock source is less than fclk_I/O/2.5. An external clock source can not be prescaled. Figure 31. Prescaler for Timer/Counter0 and Timer/Counter1(1) Note: 1. The synchronization logic on the input pins (T1/T0) is shown in Figure 30 on page 73 Special Function IO Register – SFIOR • Bit 0 – PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0 When this bit is written to one, the Timer/Counter1 and Timer/Counter0 prescaler will be reset. The bit will be cleared by hardware after the operation is performed. Writing a zero to this bit will have no effect. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler and a reset of this prescaler will affect both timers. This bit will always be read as zero. PSR10 Clear clkT1 clkT0 T1 T0 clkI/O Synchronization Synchronization Bit 7 6 5 4 3 2 1 0 – – – – ACME PUD PSR2 PSR10 SFIOR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 075 2486AA–AVR–02/2013 ATmega8(L) 16-bit Timer/Counter1 The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave generation, and signal timing measurement. The main features are: • True 16-bit Design (that is, allows 16-bit PWM) • Two Independent Output Compare Units • Double Buffered Output Compare Registers • One Input Capture Unit • Input Capture Noise Canceler • Clear Timer on Compare Match (Auto Reload) • Glitch-free, Phase Correct Pulse Width Modulator (PWM) • Variable PWM Period • Frequency Generator • External Event Counter • Four Independent Interrupt Sources (TOV1, OCF1A, OCF1B, and ICF1) Overview Most register and bit references in this section are written in general form. A lower case “n” replaces the Timer/Counter number, and a lower case “x” replaces the Output Compare unit channel. However, when using the register or bit defines in a program, the precise form must be used, that is, TCNT1 for accessing Timer/Counter1 counter value and so on. A simplified block diagram of the 16-bit Timer/Counter is shown in Figure 32 on page 76. For the actual placement of I/O pins, refer to “Pin Configurations” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “16-bit Timer/Counter Register Description” on page 96.76 2486AA–AVR–02/2013 ATmega8(L) Figure 32. 16-bit Timer/Counter Block Diagram(1) Note: 1. Refer to “Pin Configurations” on page 2, Table 22 on page 58, and Table 28 on page 63 for Timer/Counter1 pin placement and description Registers The Timer/Counter (TCNT1), Output Compare Registers (OCR1A/B), and Input Capture Register (ICR1) are all 16-bit registers. Special procedures must be followed when accessing the 16- bit registers. These procedures are described in the section “Accessing 16-bit Registers” on page 77. The Timer/Counter Control Registers (TCCR1A/B) are 8-bit registers and have no CPU access restrictions. Interrupt requests (abbreviated to Int.Req. in the figure) signals are all visible in the Timer Interrupt Flag Register (TIFR). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK). TIFR and TIMSK are not shown in the figure since these registers are shared by other timer units. The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on the T1 pin. The Clock Select logic block controls which clock source and edge the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the clock select logic is referred to as the timer clock (clkT1). The double buffered Output Compare Registers (OCR1A/B) are compared with the Timer/Counter value at all time. The result of the compare can be used by the waveform generator to generate a PWM or variable frequency output on the Output Compare Pin (OC1A/B). See “Output Compare Units” on page 83. The Compare Match event will also set the Compare Match Flag (OCF1A/B) which can be used to generate an Output Compare interrupt request. Clock Select Timer/Counter DATA BUS OCRnA OCRnB ICRn = = TCNTn Waveform Generation Waveform Generation OCnA OCnB Noise Canceler ICPn = Fixed TOP Values Edge Detector Control Logic = 0 TOP BOTTOM Count Clear Direction TOVn (Int. Req.) OCFnA (Int. Req.) OCFnB (Int.Req.) ICFn (Int.Req.) TCCRnA TCCRnB ( From Analog Comparator Ouput ) Tn Edge Detector ( From Prescaler ) clkTn77 2486AA–AVR–02/2013 ATmega8(L) The Input Capture Register can capture the Timer/Counter value at a given external (edge triggered) event on either the Input Capture Pin (ICP1) or on the Analog Comparator pins (see “Analog Comparator” on page 186). The Input Capture unit includes a digital filtering unit (Noise Canceler) for reducing the chance of capturing noise spikes. The TOP value, or maximum Timer/Counter value, can in some modes of operation be defined by either the OCR1A Register, the ICR1 Register, or by a set of fixed values. When using OCR1A as TOP value in a PWM mode, the OCR1A Register can not be used for generating a PWM output. However, the TOP value will in this case be double buffered allowing the TOP value to be changed in run time. If a fixed TOP value is required, the ICR1 Register can be used as an alternative, freeing the OCR1A to be used as PWM output. Definitions The following definitions are used extensively throughout the document: Compatibility The 16-bit Timer/Counter has been updated and improved from previous versions of the 16-bit AVR Timer/Counter. This 16-bit Timer/Counter is fully compatible with the earlier version regarding: • All 16-bit Timer/Counter related I/O Register address locations, including Timer Interrupt Registers • Bit locations inside all 16-bit Timer/Counter Registers, including Timer Interrupt Registers • Interrupt Vectors The following control bits have changed name, but have same functionality and register location: • PWM10 is changed to WGM10 • PWM11 is changed to WGM11 • CTC1 is changed to WGM12 The following bits are added to the 16-bit Timer/Counter Control Registers: • FOC1A and FOC1B are added to TCCR1A • WGM13 is added to TCCR1B The 16-bit Timer/Counter has improvements that will affect the compatibility in some special cases. Accessing 16-bit Registers The TCNT1, OCR1A/B, and ICR1 are 16-bit registers that can be accessed by the AVR CPU via the 8-bit data bus. The 16-bit register must be byte accessed using two read or write operations. The 16-bit timer has a single 8-bit register for temporary storing of the High byte of the 16-bit access. The same temporary register is shared between all 16-bit registers within the 16-bit timer. Accessing the Low byte triggers the 16-bit read or write operation. When the Low byte of a 16-bit register is written by the CPU, the High byte stored in the temporary register, and the Low byte written are both copied into the 16-bit register in the same clock cycle. When the Low byte Table 35. Definitions BOTTOM The counter reaches the BOTTOM when it becomes 0x0000. MAX The counter reaches its MAXimum when it becomes 0xFFFF (decimal 65535). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be one of the fixed values: 0x00FF, 0x01FF, or 0x03FF, or to the value stored in the OCR1A or ICR1 Register. The assignment is dependent of the mode of operation.78 2486AA–AVR–02/2013 ATmega8(L) of a 16-bit register is read by the CPU, the High byte of the 16-bit register is copied into the temporary register in the same clock cycle as the Low byte is read. Not all 16-bit accesses uses the temporary register for the High byte. Reading the OCR1A/B 16- bit registers does not involve using the temporary register. To do a 16-bit write, the High byte must be written before the Low byte. For a 16-bit read, the Low byte must be read before the High byte. The following code examples show how to access the 16-bit Timer Registers assuming that no interrupts updates the temporary register. The same principle can be used directly for accessing the OCR1A/B and ICR1 Registers. Note that when using “C”, the compiler handles the 16-bit access. Note: 1. See “About Code Examples” on page 8 The assembly code example returns the TCNT1 value in the r17:r16 Register pair. It is important to notice that accessing 16-bit registers are atomic operations. If an interrupt occurs between the two instructions accessing the 16-bit register, and the interrupt code updates the temporary register by accessing the same or any other of the 16-bit Timer Registers, then the result of the access outside the interrupt will be corrupted. Therefore, when both the main code and the interrupt code update the temporary register, the main code must disable the interrupts during the 16-bit access. The following code examples show how to do an atomic read of the TCNT1 Register contents. Reading any of the OCR1A/B or ICR1 Registers can be done by using the same principle. Assembly Code Example(1) ... ; Set TCNT1 to 0x01FF ldi r17,0x01 ldi r16,0xFF out TCNT1H,r17 out TCNT1L,r16 ; Read TCNT1 into r17:r16 in r16,TCNT1L in r17,TCNT1H ... C Code Example(1) unsigned int i; ... /* Set TCNT1 to 0x01FF */ TCNT1 = 0x1FF; /* Read TCNT1 into i */ i = TCNT1; ...79 2486AA–AVR–02/2013 ATmega8(L) Note: 1. See “About Code Examples” on page 8 The assembly code example returns the TCNT1 value in the r17:r16 Register pair. Assembly Code Example(1) TIM16_ReadTCNT1: ; Save Global Interrupt Flag in r18,SREG ; Disable interrupts cli ; Read TCNT1 into r17:r16 in r16,TCNT1L in r17,TCNT1H ; Restore Global Interrupt Flag out SREG,r18 ret C Code Example(1) unsigned int TIM16_ReadTCNT1( void ) { unsigned char sreg; unsigned int i; /* Save Global Interrupt Flag */ sreg = SREG; /* Disable interrupts */ _CLI(); /* Read TCNT1 into i */ i = TCNT1; /* Restore Global Interrupt Flag */ SREG = sreg; return i; }80 2486AA–AVR–02/2013 ATmega8(L) The following code examples show how to do an atomic write of the TCNT1 Register contents. Writing any of the OCR1A/B or ICR1 Registers can be done by using the same principle. Note: 1. See “About Code Examples” on page 8 The assembly code example requires that the r17:r16 Register pair contains the value to be written to TCNT1. Reusing the Temporary High Byte Register If writing to more than one 16-bit register where the High byte is the same for all registers written, then the High byte only needs to be written once. However, note that the same rule of atomic operation described previously also applies in this case. Timer/Counter Clock Sources The Timer/Counter can be clocked by an internal or an external clock source. The clock source is selected by the clock select logic which is controlled by the clock select (CS12:0) bits located in the Timer/Counter Control Register B (TCCR1B). For details on clock sources and prescaler, see “Timer/Counter0 and Timer/Counter1 Prescalers” on page 73. Counter Unit The main part of the 16-bit Timer/Counter is the programmable 16-bit bi-directional counter unit. Figure 33 on page 81 shows a block diagram of the counter and its surroundings. Assembly Code Example(1) TIM16_WriteTCNT1: ; Save Global Interrupt Flag in r18,SREG ; Disable interrupts cli ; Set TCNT1 to r17:r16 out TCNT1H,r17 out TCNT1L,r16 ; Restore Global Interrupt Flag out SREG,r18 ret C Code Example(1) void TIM16_WriteTCNT1( unsigned int i ) { unsigned char sreg; unsigned int i; /* Save Global Interrupt Flag */ sreg = SREG; /* Disable interrupts */ _CLI(); /* Set TCNT1 to i */ TCNT1 = i; /* Restore Global Interrupt Flag */ SREG = sreg; }81 2486AA–AVR–02/2013 ATmega8(L) Figure 33. Counter Unit Block Diagram Signal description (internal signals): count Increment or decrement TCNT1 by 1 direction Select between increment and decrement clear Clear TCNT1 (set all bits to zero) clkT1 Timer/Counter clock TOP Signalize that TCNT1 has reached maximum value BOTTOM Signalize that TCNT1 has reached minimum value (zero) The 16-bit counter is mapped into two 8-bit I/O memory locations: counter high (TCNT1H) containing the upper eight bits of the counter, and Counter Low (TCNT1L) containing the lower eight bits. The TCNT1H Register can only be indirectly accessed by the CPU. When the CPU does an access to the TCNT1H I/O location, the CPU accesses the High byte temporary register (TEMP). The temporary register is updated with the TCNT1H value when the TCNT1L is read, and TCNT1H is updated with the temporary register value when TCNT1L is written. This allows the CPU to read or write the entire 16-bit counter value within one clock cycle via the 8-bit data bus. It is important to notice that there are special cases of writing to the TCNT1 Register when the counter is counting that will give unpredictable results. The special cases are described in the sections where they are of importance. Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT1). The clkT1 can be generated from an external or internal clock source, selected by the clock select bits (CS12:0). When no clock source is selected (CS12:0 = 0) the timer is stopped. However, the TCNT1 value can be accessed by the CPU, independent of whether clkT1 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the Waveform Generation mode bits (WGM13:0) located in the Timer/Counter Control Registers A and B (TCCR1A and TCCR1B). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare Outputs OC1x. For more details about advanced counting sequences and waveform generation, see “Modes of Operation” on page 87. The Timer/Counter Overflow (TOV1) fLag is set according to the mode of operation selected by the WGM13:0 bits. TOV1 can be used for generating a CPU interrupt. Input Capture Unit The Timer/Counter incorporates an Input Capture unit that can capture external events and give them a time-stamp indicating time of occurrence. The external signal indicating an event, or multiple events, can be applied via the ICP1 pin or alternatively, via the Analog Comparator unit. TEMP (8-bit) DATA BUS (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) Control Logic count clear direction TOVn (Int. Req.) Clock Select TOP BOTTOM Tn Edge Detector ( From Prescaler ) clkTn82 2486AA–AVR–02/2013 ATmega8(L) The time-stamps can then be used to calculate frequency, duty-cycle, and other features of the signal applied. Alternatively the time-stamps can be used for creating a log of the events. The Input Capture unit is illustrated by the block diagram shown in Figure 34. The elements of the block diagram that are not directly a part of the Input Capture unit are gray shaded. The small “n” in register and bit names indicates the Timer/Counter number. Figure 34. Input Capture Unit Block Diagram When a change of the logic level (an event) occurs on the Input Capture Pin (ICP1), alternatively on the Analog Comparator Output (ACO), and this change confirms to the setting of the edge detector, a capture will be triggered. When a capture is triggered, the 16-bit value of the counter (TCNT1) is written to the Input Capture Register (ICR1). The Input Capture Flag (ICF1) is set at the same system clock as the TCNT1 value is copied into ICR1 Register. If enabled (TICIE1 = 1), the Input Capture Flag generates an Input Capture interrupt. The ICF1 Flag is automatically cleared when the interrupt is executed. Alternatively the ICF1 Flag can be cleared by software by writing a logical one to its I/O bit location. Reading the 16-bit value in the Input Capture Register (ICR1) is done by first reading the Low byte (ICR1L) and then the High byte (ICR1H). When the Low byte is read the High byte is copied into the High byte temporary register (TEMP). When the CPU reads the ICR1H I/O location it will access the TEMP Register. The ICR1 Register can only be written when using a Waveform Generation mode that utilizes the ICR1 Register for defining the counter’s TOP value. In these cases the Waveform Generation mode (WGM13:0) bits must be set before the TOP value can be written to the ICR1 Register. When writing the ICR1 Register the High byte must be written to the ICR1H I/O location before the Low byte is written to ICR1L. For more information on how to access the 16-bit registers refer to “Accessing 16-bit Registers” on page 77. Input Capture Pin Source The main trigger source for the Input Capture unit is the Input Capture Pin (ICP1). Timer/Counter 1 can alternatively use the Analog Comparator Output as trigger source for the Input Capture ICFn (Int. Req.) Analog Comparator WRITE ICRn (16-bit Register) ICRnH (8-bit) Noise Canceler ICPn Edge Detector TEMP (8-bit) DATA BUS (8-bit) ICRnL (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) ACO* ACIC* ICNC ICES83 2486AA–AVR–02/2013 ATmega8(L) unit. The Analog Comparator is selected as trigger source by setting the Analog Comparator Input Capture (ACIC) bit in the Analog Comparator Control and Status Register (ACSR). Be aware that changing trigger source can trigger a capture. The Input Capture Flag must therefore be cleared after the change. Both the Input Capture Pin (ICP1) and the Analog Comparator Output (ACO) inputs are sampled using the same technique as for the T1 pin (Figure 30 on page 73). The edge detector is also identical. However, when the noise canceler is enabled, additional logic is inserted before the edge detector, which increases the delay by four system clock cycles. Note that the input of the noise canceler and edge detector is always enabled unless the Timer/Counter is set in a Waveform Generation mode that uses ICR1 to define TOP. An Input Capture can be triggered by software by controlling the port of the ICP1 pin. Noise Canceler The noise canceler improves noise immunity by using a simple digital filtering scheme. The noise canceler input is monitored over four samples, and all four must be equal for changing the output that in turn is used by the edge detector. The noise canceler is enabled by setting the Input Capture Noise Canceler (ICNC1) bit in Timer/Counter Control Register B (TCCR1B). When enabled the noise canceler introduces additional four system clock cycles of delay from a change applied to the input, to the update of the ICR1 Register. The noise canceler uses the system clock and is therefore not affected by the prescaler. Using the Input Capture Unit The main challenge when using the Input Capture unit is to assign enough processor capacity for handling the incoming events. The time between two events is critical. If the processor has not read the captured value in the ICR1 Register before the next event occurs, the ICR1 will be overwritten with a new value. In this case the result of the capture will be incorrect. When using the Input Capture interrupt, the ICR1 Register should be read as early in the interrupt handler routine as possible. Even though the Input Capture interrupt has relatively high priority, the maximum interrupt response time is dependent on the maximum number of clock cycles it takes to handle any of the other interrupt requests. Using the Input Capture unit in any mode of operation when the TOP value (resolution) is actively changed during operation, is not recommended. Measurement of an external signal’s duty cycle requires that the trigger edge is changed after each capture. Changing the edge sensing must be done as early as possible after the ICR1 Register has been read. After a change of the edge, the Input Capture Flag (ICF1) must be cleared by software (writing a logical one to the I/O bit location). For measuring frequency only, the clearing of the ICF1 Flag is not required (if an interrupt handler is used). Output Compare Units The 16-bit comparator continuously compares TCNT1 with the Output Compare Register (OCR1x). If TCNT equals OCR1x the comparator signals a match. A match will set the Output Compare Flag (OCF1x) at the next timer clock cycle. If enabled (OCIE1x = 1), the Output Compare Flag generates an Output Compare interrupt. The OCF1x Flag is automatically cleared when the interrupt is executed. Alternatively the OCF1x Flag can be cleared by software by writing a logical one to its I/O bit location. The waveform generator uses the match signal to generate an output according to operating mode set by the Waveform Generation mode (WGM13:0) bits and Compare Output mode (COM1x1:0) bits. The TOP and BOTTOM signals are used by the waveform generator for handling the special cases of the extreme values in some modes of operation (see “Modes of Operation” on page 87). A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (that is counter resolution). In addition to the counter resolution, the TOP value defines the period time for waveforms generated by the waveform generator.84 2486AA–AVR–02/2013 ATmega8(L) Figure 35 shows a block diagram of the Output Compare unit. The small “n” in the register and bit names indicates the device number (n = 1 for Timer/Counter 1), and the “x” indicates Output Compare unit (A/B). The elements of the block diagram that are not directly a part of the Output Compare unit are gray shaded. Figure 35. Output Compare Unit, Block Diagram The OCR1x Register is double buffered when using any of the twelve Pulse Width Modulation (PWM) modes. For the normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR1x Compare Register to either TOP or BOTTOM of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR1x Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR1x Buffer Register, and if double buffering is disabled the CPU will access the OCR1x directly. The content of the OCR1x (Buffer or Compare) Register is only changed by a write operation (the Timer/Counter does not update this register automatically as the TCNT1 and ICR1 Register). Therefore OCR1x is not read via the High byte temporary register (TEMP). However, it is a good practice to read the Low byte first as when accessing other 16-bit registers. Writing the OCR1x Registers must be done via the TEMP Register since the compare of all 16-bit is done continuously. The High byte (OCR1xH) has to be written first. When the High byte I/O location is written by the CPU, the TEMP Register will be updated by the value written. Then when the Low byte (OCR1xL) is written to the lower eight bits, the High byte will be copied into the upper 8-bits of either the OCR1x buffer or OCR1x Compare Register in the same system clock cycle. For more information of how to access the 16-bit registers refer to “Accessing 16-bit Registers” on page 77. OCFnx (Int.Req.) = (16-bit Comparator ) OCRnx Buffer (16-bit Register) OCRnxH Buf. (8-bit) OCnx TEMP (8-bit) DATA BUS (8-bit) OCRnxL Buf. (8-bit) TCNTn (16-bit Counter) TCNTnH (8-bit) TCNTnL (8-bit) WGMn3:0 COMnx1:0 OCRnx (16-bit Register) OCRnxH (8-bit) OCRnxL (8-bit) Waveform Generator TOP BOTTOM85 2486AA–AVR–02/2013 ATmega8(L) Force Output Compare In non-PWM Waveform Generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC1x) bit. Forcing Compare Match will not set the OCF1x Flag or reload/clear the timer, but the OC1x pin will be updated as if a real Compare Match had occurred (the COM1x1:0 bits settings define whether the OC1x pin is set, cleared or toggled). Compare Match Blocking by TCNT1 Write All CPU writes to the TCNT1 Register will block any Compare Match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR1x to be initialized to the same value as TCNT1 without triggering an interrupt when the Timer/Counter clock is enabled. Using the Output Compare Unit Since writing TCNT1 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT1 when using any of the Output Compare channels, independent of whether the Timer/Counter is running or not. If the value written to TCNT1 equals the OCR1x value, the Compare Match will be missed, resulting in incorrect waveform generation. Do not write the TCNT1 equal to TOP in PWM modes with variable TOP values. The Compare Match for the TOP will be ignored and the counter will continue to 0xFFFF. Similarly, do not write the TCNT1 value equal to BOTTOM when the counter is downcounting. The setup of the OC1x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC1x value is to use the Force Output Compare (FOC1x) strobe bits in Normal mode. The OC1x Register keeps its value even when changing between Waveform Generation modes. Be aware that the COM1x1:0 bits are not double buffered together with the compare value. Changing the COM1x1:0 bits will take effect immediately. Compare Match Output Unit The Compare Output mode (COM1x1:0) bits have two functions. The waveform generator uses the COM1x1:0 bits for defining the Output Compare (OC1x) state at the next Compare Match. Secondly the COM1x1:0 bits control the OC1x pin output source. Figure 36 on page 86 shows a simplified schematic of the logic affected by the COM1x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM1x1:0 bits are shown. When referring to the OC1x state, the reference is for the internal OC1x Register, not the OC1x pin. If a System Reset occur, the OC1x Register is reset to “0”.86 2486AA–AVR–02/2013 ATmega8(L) Figure 36. Compare Match Output Unit, Schematic The general I/O port function is overridden by the Output Compare (OC1x) from the waveform generator if either of the COM1x1:0 bits are set. However, the OC1x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC1x pin (DDR_OC1x) must be set as output before the OC1x value is visible on the pin. The port override function is generally independent of the Waveform Generation mode, but there are some exceptions. Refer to Table 36 on page 96, Table 37 on page 96 and Table 38 on page 97 for details. The design of the Output Compare Pin logic allows initialization of the OC1x state before the output is enabled. Note that some COM1x1:0 bit settings are reserved for certain modes of operation. See “16-bit Timer/Counter Register Description” on page 96. The COM1x1:0 bits have no effect on the Input Capture unit. PORT DDR D Q D Q OCnx OCnx Pin D Q Waveform Generator COMnx1 COMnx0 0 1 DATABUS FOCnx clkI/O87 2486AA–AVR–02/2013 ATmega8(L) Compare Output Mode and Waveform Generation The waveform generator uses the COM1x1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM1x1:0 = 0 tells the waveform generator that no action on the OC1x Register is to be performed on the next Compare Match. For compare output actions in the non-PWM modes refer to Table 36 on page 96. For fast PWM mode refer to Table 37 on page 96, and for phase correct and phase and frequency correct PWM refer to Table 38 on page 97. A change of the COM1x1:0 bits state will have effect at the first Compare Match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC1x strobe bits. Modes of Operation The mode of operation (that is, the behavior of the Timer/Counter and the Output Compare pins) is defined by the combination of the Waveform Generation mode (WGM13:0) and Compare Output mode (COM1x1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM1x1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM1x1:0 bits control whether the output should be set, cleared or toggle at a Compare Match. See “Compare Match Output Unit” on page 85. For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 94. Normal Mode The simplest mode of operation is the Normal mode (WGM13:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 16-bit value (MAX = 0xFFFF) and then restarts from the BOTTOM (0x0000). In normal operation the Timer/Counter Overflow Flag (TOV1) will be set in the same timer clock cycle as the TCNT1 becomes zero. The TOV1 Flag in this case behaves like a 17th bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV1 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Input Capture unit is easy to use in Normal mode. However, observe that the maximum interval between the external events must not exceed the resolution of the counter. If the interval between events are too long, the timer overflow interrupt or the prescaler must be used to extend the resolution for the capture unit. The Output Compare units can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. Clear Timer on Compare Match (CTC) Mode In Clear Timer on Compare or CTC mode (WGM13:0 = 4 or 12), the OCR1A or ICR1 Register are used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT1) matches either the OCR1A (WGM13:0 = 4) or the ICR1 (WGM13:0 = 12). The OCR1A or ICR1 define the top value for the counter, hence also its resolution. This mode allows greater control of the Compare Match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 37 on page 88. The counter value (TCNT1) increases until a Compare Match occurs with either OCR1A or ICR1, and then counter (TCNT1) is cleared.88 2486AA–AVR–02/2013 ATmega8(L) Figure 37. CTC Mode, Timing Diagram An interrupt can be generated at each time the counter value reaches the TOP value by either using the OCF1A or ICF1 Flag according to the register used to define the TOP value. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR1A or ICR1 is lower than the current value of TCNT1, the counter will miss the Compare Match. The counter will then have to count to its maximum value (0xFFFF) and wrap around starting at 0x0000 before the Compare Match can occur. In many cases this feature is not desirable. An alternative will then be to use the fast PWM mode using OCR1A for defining TOP (WGM13:0 = 15) since the OCR1A then will be double buffered. For generating a waveform output in CTC mode, the OC1A output can be set to toggle its logical level on each Compare Match by setting the Compare Output mode bits to toggle mode (COM1A1:0 = 1). The OC1A value will not be visible on the port pin unless the data direction for the pin is set to output (DDR_OC1A = 1). The waveform generated will have a maximum frequency of fOC1A = fclk_I/O/2 when OCR1A is set to zero (0x0000). The waveform frequency is defined by the following equation: The N variable represents the prescaler factor (1, 8, 64, 256, or 1024). As for the Normal mode of operation, the TOV1 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x0000. Fast PWM Mode The fast Pulse Width Modulation or fast PWM mode (WGM13:0 = 5, 6, 7, 14, or 15) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM options by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the Compare Match between TCNT1 and OCR1x, and set at BOTTOM. In inverting Compare Output mode output is set on Compare Match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct and phase and frequency correct PWM modes that use dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), hence reduces total system cost. The PWM resolution for fast PWM can be fixed to 8-bit, 9-bit, or 10-bit, or defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the TCNTn OCnA (Toggle) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 (COMnA1:0 = 1) f OCnA f clk_I/O 2   N   1 + OCRnA = --------------------------------------------------89 2486AA–AVR–02/2013 ATmega8(L) maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated by using the following equation: In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGM13:0 = 5, 6, or 7), the value in ICR1 (WGM13:0 = 14), or the value in OCR1A (WGM13:0 = 15). The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 38. The figure shows fast PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a Compare Match occurs. Figure 38. Fast PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set each time the counter reaches TOP. In addition the OCF1A or ICF1 Flag is set at the same timer clock cycle as TOV1 is set when either OCR1A or ICR1 is used for defining the TOP value. If one of the interrupts are enabled, the interrupt handler routine can be used for updating the TOP and compare values. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a Compare Match will never occur between the TCNT1 and the OCR1x. Note that when using fixed TOP values the unused bits are masked to zero when any of the OCR1x Registers are written. The procedure for updating ICR1 differs from updating OCR1A when used for defining the TOP value. The ICR1 Register is not double buffered. This means that if ICR1 is changed to a low value when the counter is running with none or a low prescaler value, there is a risk that the new ICR1 value written is lower than the current value of TCNT1. The result will then be that the counter will miss the Compare Match at the TOP value. The counter will then have to count to the MAX value (0xFFFF) and wrap around starting at 0x0000 before the Compare Match can occur. The OCR1A Register, however, is double buffered. This feature allows the OCR1A I/O location to be written anytime. When the OCR1A I/O location is written the value written will be put into the OCR1A Buffer Register. The OCR1A Compare Register will then be updated with the value in the Buffer Register at the next timer clock cycle the TCNT1 matches TOP. The update is done at the same timer clock cycle as the TCNT1 is cleared and the TOV1 Flag is set. RFPWM log  TOP + 1 log  2 = ----------------------------------- TCNTn OCRnx / TOP Update and TOVn Interrupt Flag Set and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 5 6 7 8 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)90 2486AA–AVR–02/2013 ATmega8(L) Using the ICR1 Register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A Register is free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed (by changing the TOP value), using the OCR1A as TOP is clearly a better choice due to its double buffer feature. In fast PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to 3. See Table 37 on page 96. The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the Compare Match between OCR1x and TCNT1, and clearing (or setting) the OC1x Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represents special cases when generating a PWM waveform output in the fast PWM mode. If the OCR1x is set equal to BOTTOM (0x0000) the output will be a narrow spike for each TOP+1 timer clock cycle. Setting the OCR1x equal to TOP will result in a constant high or low output (depending on the polarity of the output set by the COM1x1:0 bits). A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC1A to toggle its logical level on each Compare Match (COM1A1:0 = 1). This applies only if OCR1A is used to define the TOP value (WGM13:0 = 15). The waveform generated will have a maximum frequency of fOC1A = fclk_I/O/2 when OCR1A is set to zero (0x0000). This feature is similar to the OC1A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. Phase Correct PWM Mode The phase correct Pulse Width Modulation or phase correct PWM mode (WGM13:0 = 1, 2, 3, 10, or 11) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is, like the phase and frequency correct PWM mode, based on a dualslope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the Compare Match between TCNT1 and OCR1x while upcounting, and set on the Compare Match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode can be fixed to 8-bit, 9-bit, or 10-bit, or defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated by using the following equation: In phase correct PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGM13:0 = 1, 2, or 3), the value in ICR1 (WGM13:0 = 10), or the value in OCR1A (WGM13:0 = 11). The counter has then reached the TOP and changes the count direction. The TCNT1 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 39 on page 91. The figure shows phase correct PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the dual-slope operaf OCnxPWM f clk_I/O N    1 + TOP = ----------------------------------- RPCPWM log  TOP + 1 log  2 = -----------------------------------91 2486AA–AVR–02/2013 ATmega8(L) tion. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a Compare Match occurs. Figure 39. Phase Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set each time the counter reaches BOTTOM. When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 Flag is set accordingly at the same timer clock cycle as the OCR1x Registers are updated with the double buffer value (at TOP). The Interrupt Flags can be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a Compare Match will never occur between the TCNT1 and the OCR1x. Note that when using fixed TOP values, the unused bits are masked to zero when any of the OCR1x Registers are written. As the third period shown in Figure 39 illustrates, changing the TOP actively while the Timer/Counter is running in the Phase Correct mode can result in an unsymmetrical output. The reason for this can be found in the time of update of the OCR1x Register. Since the OCR1x update occurs at TOP, the PWM period starts and ends at TOP. This implies that the length of the falling slope is determined by the previous TOP value, while the length of the rising slope is determined by the new TOP value. When these two values differ the two slopes of the period will differ in length. The difference in length gives the unsymmetrical result on the output. It is recommended to use the Phase and Frequency Correct mode instead of the Phase Correct mode when changing the TOP value while the Timer/Counter is running. When using a static TOP value there are practically no differences between the two modes of operation. In phase correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to 3. See Table 38 on page 97. The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the Compare Match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x Register at Compare Match between OCR1x and TCNT1 when OCRnx / TOP Update and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) 1 2 3 4 TOVn Interrupt Flag Set (Interrupt on Bottom) TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)92 2486AA–AVR–02/2013 ATmega8(L) the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WMG13:0 = 11) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. Phase and Frequency Correct PWM Mode The phase and frequency correct Pulse Width Modulation, or phase and frequency correct PWM mode (WGM13:0 = 8 or 9) provides a high resolution phase and frequency correct PWM waveform generation option. The phase and frequency correct PWM mode is, like the phase correct PWM mode, based on a dual-slope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC1x) is cleared on the Compare Match between TCNT1 and OCR1x while upcounting, and set on the Compare Match while downcounting. In inverting Compare Output mode, the operation is inverted. The dual-slope operation gives a lower maximum operation frequency compared to the single-slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The main difference between the phase correct, and the phase and frequency correct PWM mode is the time the OCR1x Register is updated by the OCR1x Buffer Register, (see Figure 39 on page 91 and Figure 40 on page 93). The PWM resolution for the phase and frequency correct PWM mode can be defined by either ICR1 or OCR1A. The minimum resolution allowed is 2-bit (ICR1 or OCR1A set to 0x0003), and the maximum resolution is 16-bit (ICR1 or OCR1A set to MAX). The PWM resolution in bits can be calculated using the following equation: In phase and frequency correct PWM mode the counter is incremented until the counter value matches either the value in ICR1 (WGM13:0 = 8), or the value in OCR1A (WGM13:0 = 9). The counter has then reached the TOP and changes the count direction. The TCNT1 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct and frequency correct PWM mode is shown on Figure 40 on page 93. The figure shows phase and frequency correct PWM mode when OCR1A or ICR1 is used to define TOP. The TCNT1 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT1 slopes represent compare matches between OCR1x and TCNT1. The OC1x Interrupt Flag will be set when a Compare Match occurs. f OCnxPCPWM f clk_I/O 2   N TOP = ---------------------------- RPFCPWM log  TOP + 1 log  2 = -----------------------------------93 2486AA–AVR–02/2013 ATmega8(L) Figure 40. Phase and Frequency Correct PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV1) is set at the same timer clock cycle as the OCR1x Registers are updated with the double buffer value (at BOTTOM). When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 Flag set when TCNT1 has reached TOP. The Interrupt Flags can then be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a Compare Match will never occur between the TCNT1 and the OCR1x. As Figure 40 shows the output generated is, in contrast to the Phase Correct mode, symmetrical in all periods. Since the OCR1x Registers are updated at BOTTOM, the length of the rising and the falling slopes will always be equal. This gives symmetrical output pulses and is therefore frequency correct. Using the ICR1 Register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A Register is free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed by changing the TOP value, using the OCR1A as TOP is clearly a better choice due to its double buffer feature. In phase and frequency correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins. Setting the COM1x1:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM1x1:0 to 3. See Table 38 on page 97. The actual OC1x value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x Register at the Compare Match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x Register at Compare Match between OCR1x and TCNT1 when the counter decrements. The PWM frequency for the output when using phase and frequency correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCR1x Register represents special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the OCRnx / TOP Update and TOVn Interrupt Flag Set (Interrupt on Bottom) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) 1 2 3 4 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) f OCnxPFCPWM f clk_I/O 2   N TOP = ----------------------------94 2486AA–AVR–02/2013 ATmega8(L) output will be continuously low and if set equal to TOP the output will be set to high for noninverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. Timer/Counter Timing Diagrams The Timer/Counter is a synchronous design and the timer clock (clkT1) is therefore shown as a clock enable signal in the following figures. The figures include information on when Interrupt Flags are set, and when the OCR1x Register is updated with the OCR1x buffer value (only for modes utilizing double buffering). Figure 41 shows a timing diagram for the setting of OCF1x. Figure 41. Timer/Counter Timing Diagram, Setting of OCF1x, no Prescaling Figure 42 shows the same timing data, but with the prescaler enabled. Figure 42. Timer/Counter Timing Diagram, Setting of OCF1x, with Prescaler (fclk_I/O/8) Figure 43 on page 95 shows the count sequence close to TOP in various modes. When using phase and frequency correct PWM mode the OCR1x Register is updated at BOTTOM. The timclkTn (clkI/O/1) OCFnx clkI/O OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 OCFnx OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8)95 2486AA–AVR–02/2013 ATmega8(L) ing diagrams will be the same, but TOP should be replaced by BOTTOM, TOP-1 by BOTTOM+1 and so on. The same renaming applies for modes that set the TOV1 Flag at BOTTOM. Figure 43. Timer/Counter Timing Diagram, no Prescaling Figure 44 shows the same timing data, but with the prescaler enabled. Figure 44. Timer/Counter Timing Diagram, with Prescaler (fclk_I/O/8) TOVn (FPWM) and ICFn (if used as TOP) OCRnx (Update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx Value New OCRnx Value TOP - 1 TOP BOTTOM BOTTOM + 1 clkTn (clkI/O/1) clkI/O TOVn (FPWM) and ICFn (if used as TOP) OCRnx (Update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx Value New OCRnx Value TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8)96 2486AA–AVR–02/2013 ATmega8(L) 16-bit Timer/Counter Register Description Timer/Counter 1 Control Register A – TCCR1A • Bit 7:6 – COM1A1:0: Compare Output Mode for channel A • Bit 5:4 – COM1B1:0: Compare Output Mode for channel B The COM1A1:0 and COM1B1:0 control the Output Compare Pins (OC1A and OC1B respectively) behavior. If one or both of the COM1A1:0 bits are written to one, the OC1A output overrides the normal port functionality of the I/O pin it is connected to. If one or both of the COM1B1:0 bit are written to one, the OC1B output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC1A or OC1B pin must be set in order to enable the output driver. When the OC1A or OC1B is connected to the pin, the function of the COM1x1:0 bits is dependent of the WGM13:0 bits setting. Table 36 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to a normal or a CTC mode (non-PWM). Table 37 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the fast PWM mode. Note: 1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. In this case the Compare Match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on page 88 for more details Bit 7 6 5 4 3 2 1 0 COM1A1 COM1A0 COM1B1 COM1B0 FOC1A FOC1B WGM11 WGM10 TCCR1A Read/Write R/W R/W R/W R/W W W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 36. Compare Output Mode, Non-PWM COM1A1/ COM1B1 COM1A0/ COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 Toggle OC1A/OC1B on Compare Match 1 0 Clear OC1A/OC1B on Compare Match (Set output to low level) 1 1 Set OC1A/OC1B on Compare Match (Set output to high level) Table 37. Compare Output Mode, Fast PWM(1) COM1A1/ COM1B1 COM1A0/ COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 WGM13:0 = 15: Toggle OC1A on Compare Match, OC1B disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B disconnected. 1 0 Clear OC1A/OC1B on Compare Match, set OC1A/OC1B at BOTTOM, (non-inverting mode) 1 1 Set OC1A/OC1B on Compare Match, clear OC1A/OC1B at BOTTOM, (inverting mode)97 2486AA–AVR–02/2013 ATmega8(L) Table 38 shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the phase correct or the phase and frequency correct, PWM mode. Note: 1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. See “Phase Correct PWM Mode” on page 90 for more details • Bit 3 – FOC1A: Force Output Compare for channel A • Bit 2 – FOC1B: Force Output Compare for channel B The FOC1A/FOC1B bits are only active when the WGM13:0 bits specifies a non-PWM mode. However, for ensuring compatibility with future devices, these bits must be set to zero when TCCR1A is written when operating in a PWM mode. When writing a logical one to the FOC1A/FOC1B bit, an immediate Compare Match is forced on the waveform generation unit. The OC1A/OC1B output is changed according to its COM1x1:0 bits setting. Note that the FOC1A/FOC1B bits are implemented as strobes. Therefore it is the value present in the COM1x1:0 bits that determine the effect of the forced compare. A FOC1A/FOC1B strobe will not generate any interrupt nor will it clear the timer in Clear Timer on Compare Match (CTC) mode using OCR1A as TOP. The FOC1A/FOC1B bits are always read as zero. • Bit 1:0 – WGM11:0: Waveform Generation Mode Combined with the WGM13:2 bits found in the TCCR1B Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 39. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and three types of Pulse Width Modulation (PWM) modes (see “Modes of Operation” on page 87). Table 38. Compare Output Mode, Phase Correct and Phase and Frequency Correct PWM(1) COM1A1/ COM1B1 COM1A0/ COM1B0 Description 0 0 Normal port operation, OC1A/OC1B disconnected. 0 1 WGM13:0 = 9 or 14: Toggle OC1A on Compare Match, OC1B disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B disconnected. 1 0 Clear OC1A/OC1B on Compare Match when up-counting. Set OC1A/OC1B on Compare Match when downcounting. 1 1 Set OC1A/OC1B on Compare Match when up-counting. Clear OC1A/OC1B on Compare Match when downcounting. Table 39. Waveform Generation Mode Bit Description Mode WGM13 WGM12 (CTC1) WGM11 (PWM11) WGM10 (PWM10) Timer/Counter Mode of Operation(1) TOP Update of OCR1x TOV1 Flag Set on 0 0 0 0 0 Normal 0xFFFF Immediate MAX 1 0 0 0 1 PWM, Phase Correct, 8-bit 0x00FF TOP BOTTOM 2 0 0 1 0 PWM, Phase Correct, 9-bit 0x01FF TOP BOTTOM 3 0 0 1 1 PWM, Phase Correct, 10-bit 0x03FF TOP BOTTOM 4 0 1 0 0 CTC OCR1A Immediate MAX 5 0 1 0 1 Fast PWM, 8-bit 0x00FF BOTTOM TOP 6 0 1 1 0 Fast PWM, 9-bit 0x01FF BOTTOM TOP98 2486AA–AVR–02/2013 ATmega8(L) Note: 1. The CTC1 and PWM11:0 bit definition names are obsolete. Use the WGM12:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer Timer/Counter 1 Control Register B – TCCR1B • Bit 7 – ICNC1: Input Capture Noise Canceler Setting this bit (to one) activates the Input Capture Noise Canceler. When the noise canceler is activated, the input from the Input Capture Pin (ICP1) is filtered. The filter function requires four successive equal valued samples of the ICP1 pin for changing its output. The Input Capture is therefore delayed by four Oscillator cycles when the noise canceler is enabled. • Bit 6 – ICES1: Input Capture Edge Select This bit selects which edge on the Input Capture Pin (ICP1) that is used to trigger a capture event. When the ICES1 bit is written to zero, a falling (negative) edge is used as trigger, and when the ICES1 bit is written to one, a rising (positive) edge will trigger the capture. When a capture is triggered according to the ICES1 setting, the counter value is copied into the Input Capture Register (ICR1). The event will also set the Input Capture Flag (ICF1), and this can be used to cause an Input Capture Interrupt, if this interrupt is enabled. When the ICR1 is used as TOP value (see description of the WGM13:0 bits located in the TCCR1A and the TCCR1B Register), the ICP1 is disconnected and consequently the Input Capture function is disabled. • Bit 5 – Reserved Bit This bit is reserved for future use. For ensuring compatibility with future devices, this bit must be written to zero when TCCR1B is written. • Bit 4:3 – WGM13:2: Waveform Generation Mode See TCCR1A Register description. • Bit 2:0 – CS12:0: Clock Select The three clock select bits select the clock source to be used by the Timer/Counter, see Figure 41 on page 94 and Figure 42 on page 94. 7 0 1 1 1 Fast PWM, 10-bit 0x03FF BOTTOM TOP 8 1 0 0 0 PWM, Phase and Frequency Correct ICR1 BOTTOM BOTTOM 9 1 0 0 1 PWM, Phase and Frequency Correct OCR1A BOTTOM BOTTOM 10 1 0 1 0 PWM, Phase Correct ICR1 TOP BOTTOM 11 1 0 1 1 PWM, Phase Correct OCR1A TOP BOTTOM 12 1 1 0 0 CTC ICR1 Immediate MAX 13 1 1 0 1 (Reserved) – – – 14 1 1 1 0 Fast PWM ICR1 BOTTOM TOP 15 1 1 1 1 Fast PWM OCR1A BOTTOM TOP Table 39. Waveform Generation Mode Bit Description (Continued) Mode WGM13 WGM12 (CTC1) WGM11 (PWM11) WGM10 (PWM10) Timer/Counter Mode of Operation(1) TOP Update of OCR1x TOV1 Flag Set on Bit 7 6 5 4 3 2 1 0 ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 TCCR1B Read/Write R/W R/W R R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 099 2486AA–AVR–02/2013 ATmega8(L) If external pin modes are used for the Timer/Counter1, transitions on the T1 pin will clock the counter even if the pin is configured as an output. This feature allows software control of the counting. Timer/Counter 1 – TCNT1H and TCNT1L The two Timer/Counter I/O locations (TCNT1H and TCNT1L, combined TCNT1) give direct access, both for read and for write operations, to the Timer/Counter unit 16-bit counter. To ensure that both the high and Low bytes are read and written simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 77. Modifying the counter (TCNT1) while the counter is running introduces a risk of missing a Compare Match between TCNT1 and one of the OCR1x Registers. Writing to the TCNT1 Register blocks (removes) the Compare Match on the following timer clock for all compare units. Output Compare Register 1 A – OCR1AH and OCR1AL Output Compare Register 1 B – OCR1BH and OCR1BL Table 40. Clock Select Bit Description CS12 CS11 CS10 Description 0 0 0 No clock source. (Timer/Counter stopped) 0 0 1 clkI/O/1 (No prescaling) 0 1 0 clkI/O/8 (From prescaler) 0 1 1 clkI/O/64 (From prescaler) 1 0 0 clkI/O/256 (From prescaler) 1 0 1 clkI/O/1024 (From prescaler) 1 1 0 External clock source on T1 pin. Clock on falling edge 1 1 1 External clock source on T1 pin. Clock on rising edge Bit 7 6 5 4 3 2 1 0 TCNT1[15:8] TCNT1H TCNT1[7:0] TCNT1L Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1A[15:8] OCR1AH OCR1A[7:0] OCR1AL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1B[15:8] OCR1BH OCR1B[7:0] OCR1BL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0100 2486AA–AVR–02/2013 ATmega8(L) The Output Compare Registers contain a 16-bit value that is continuously compared with the counter value (TCNT1). A match can be used to generate an Output Compare Interrupt, or to generate a waveform output on the OC1x pin. The Output Compare Registers are 16-bit in size. To ensure that both the high and Low bytes are written simultaneously when the CPU writes to these registers, the access is performed using an 8-bit temporary High byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 77. Input Capture Register 1 – ICR1H and ICR1L The Input Capture is updated with the counter (TCNT1) value each time an event occurs on the ICP1 pin (or optionally on the Analog Comparator Output for Timer/Counter1). The Input Capture can be used for defining the counter TOP value. The Input Capture Register is 16-bit in size. To ensure that both the high and Low bytes are read simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit Registers” on page 77. Timer/Counter Interrupt Mask Register – TIMSK(1) Note: 1. This register contains interrupt control bits for several Timer/Counters, but only Timer1 bits are described in this section. The remaining bits are described in their respective timer sections • Bit 5 – TICIE1: Timer/Counter1, Input Capture Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Input Capture Interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 46) is executed when the ICF1 Flag, located in TIFR, is set. • Bit 4 – OCIE1A: Timer/Counter1, Output Compare A Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Output Compare A match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 46) is executed when the OCF1A Flag, located in TIFR, is set. • Bit 3 – OCIE1B: Timer/Counter1, Output Compare B Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Output Compare B match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 46) is executed when the OCF1B Flag, located in TIFR, is set. • Bit 2 – TOIE1: Timer/Counter1, Overflow Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Counter1 Overflow Interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 46) is executed when the TOV1 Flag, located in TIFR, is set. Bit 7 6 5 4 3 2 1 0 ICR1[15:8] ICR1H ICR1[7:0] ICR1L Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 TIMSK Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0101 2486AA–AVR–02/2013 ATmega8(L) Timer/Counter Interrupt Flag Register – TIFR(1) Note: 1. This register contains flag bits for several Timer/Counters, but only Timer1 bits are described in this section. The remaining bits are described in their respective timer sections • Bit 5 – ICF1: Timer/Counter1, Input Capture Flag This flag is set when a capture event occurs on the ICP1 pin. When the Input Capture Register (ICR1) is set by the WGM13:0 to be used as the TOP value, the ICF1 Flag is set when the counter reaches the TOP value. ICF1 is automatically cleared when the Input Capture Interrupt Vector is executed. Alternatively, ICF1 can be cleared by writing a logic one to its bit location. • Bit 4 – OCF1A: Timer/Counter1, Output Compare A Match Flag This flag is set in the timer clock cycle after the counter (TCNT1) value matches the Output Compare Register A (OCR1A). Note that a Forced Output Compare (FOC1A) strobe will not set the OCF1A Flag. OCF1A is automatically cleared when the Output Compare Match A Interrupt Vector is executed. Alternatively, OCF1A can be cleared by writing a logic one to its bit location. • Bit 3 – OCF1B: Timer/Counter1, Output Compare B Match Flag This flag is set in the timer clock cycle after the counter (TCNT1) value matches the Output Compare Register B (OCR1B). Note that a Forced Output Compare (FOC1B) strobe will not set the OCF1B Flag. OCF1B is automatically cleared when the Output Compare Match B Interrupt Vector is executed. Alternatively, OCF1B can be cleared by writing a logic one to its bit location. • Bit 2 – TOV1: Timer/Counter1, Overflow Flag The setting of this flag is dependent of the WGM13:0 bits setting. In normal and CTC modes, the TOV1 Flag is set when the timer overflows. Refer to Table 39 on page 97 for the TOV1 Flag behavior when using another WGM13:0 bit setting. TOV1 is automatically cleared when the Timer/Counter1 Overflow Interrupt Vector is executed. Alternatively, TOV1 can be cleared by writing a logic one to its bit location. Bit 7 6 5 4 3 2 1 0 OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 TIFR Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0102 2486AA–AVR–02/2013 ATmega8(L) 8-bit Timer/Counter2 with PWM and Asynchronous Operation Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. The main features are: • Single Channel Counter • Clear Timer on Compare Match (Auto Reload) • Glitch-free, phase Correct Pulse Width Modulator (PWM) • Frequency Generator • 10-bit Clock Prescaler • Overflow and Compare Match Interrupt Sources (TOV2 and OCF2) • Allows Clocking from External 32kHz Watch Crystal Independent of the I/O Clock Overview A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 45. For the actual placement of I/O pins, refer to “Pin Configurations” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “8-bit Timer/Counter Register Description” on page 114. Figure 45. 8-bit Timer/Counter Block Diagram Timer/Counter DATA BUS = TCNTn Waveform Generation OCn = 0 Control Logic = 0xFF BOTTOM TOP count clear direction TOVn (Int. Req.) OCn (Int. Req.) Synchronization Unit OCRn TCCRn ASSRn Status Flags clkI/O clkASY Synchronized Status Flags asynchronous Mode Select (ASn) TOSC1 T/C Oscillator TOSC2 Prescaler clkTn clkI/O103 2486AA–AVR–02/2013 ATmega8(L) Registers The Timer/Counter (TCNT2) and Output Compare Register (OCR2) are 8-bit registers. Interrupt request (shorten as Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFR). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK). TIFR and TIMSK are not shown in the figure since these registers are shared by other timer units. The Timer/Counter can be clocked internally, via the prescaler, or asynchronously clocked from the TOSC1/2 pins, as detailed later in this section. The asynchronous operation is controlled by the Asynchronous Status Register (ASSR). The Clock Select logic block controls which clock source the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the clock select logic is referred to as the timer clock (clkT2). The double buffered Output Compare Register (OCR2) is compared with the Timer/Counter value at all times. The result of the compare can be used by the waveform generator to generate a PWM or variable frequency output on the Output Compare Pin (OC2). For details, see “Output Compare Unit” on page 105. The Compare Match event will also set the Compare Flag (OCF2) which can be used to generate an Output Compare interrupt request. Definitions Many register and bit references in this document are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 2. However, when using the register or bit defines in a program, the precise form must be used (that is, TCNT2 for accessing Timer/Counter2 counter value and so on). The definitions in Table 41 are also used extensively throughout the document. Timer/Counter Clock Sources The Timer/Counter can be clocked by an internal synchronous or an external asynchronous clock source. The clock source clkT2 is by default equal to the MCU clock, clkI/O. When the AS2 bit in the ASSR Register is written to logic one, the clock source is taken from the Timer/Counter Oscillator connected to TOSC1 and TOSC2. For details on asynchronous operation, see “Asynchronous Status Register – ASSR” on page 117. For details on clock sources and prescaler, see “Timer/Counter Prescaler” on page 120. Table 41. Definitions BOTTOM The counter reaches the BOTTOM when it becomes zero (0x00). MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be the fixed value 0xFF (MAX) or the value stored in the OCR2 Register. The assignment is dependent on the mode of operation.104 2486AA–AVR–02/2013 ATmega8(L) Counter Unit The main part of the 8-bit Timer/Counter is the programmable bi-directional counter unit. Figure 46 shows a block diagram of the counter and its surrounding environment. Figure 46. Counter Unit Block Diagram Signal description (internal signals): count Increment or decrement TCNT2 by 1 direction Selects between increment and decrement clear Clear TCNT2 (set all bits to zero) clkT2 Timer/Counter clock TOP Signalizes that TCNT2 has reached maximum value BOTTOM Signalizes that TCNT2 has reached minimum value (zero) Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT2). clkT2 can be generated from an external or internal clock source, selected by the clock select bits (CS22:0). When no clock source is selected (CS22:0 = 0) the timer is stopped. However, the TCNT2 value can be accessed by the CPU, regardless of whether clkT2 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the WGM21 and WGM20 bits located in the Timer/Counter Control Register (TCCR2). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare Output OC2. For more details about advanced counting sequences and waveform generation, see “Modes of Operation” on page 108. The Timer/Counter Overflow (TOV2) Flag is set according to the mode of operation selected by the WGM21:0 bits. TOV2 can be used for generating a CPU interrupt. DATA BUS TCNTn Control Logic count TOVn (Int. Req.) BOTTOM TOP direction clear TOSC1 T/C Oscillator TOSC2 Prescaler clkI/O clk Tn105 2486AA–AVR–02/2013 ATmega8(L) Output Compare Unit The 8-bit comparator continuously compares TCNT2 with the Output Compare Register (OCR2). Whenever TCNT2 equals OCR2, the comparator signals a match. A match will set the Output Compare Flag (OCF2) at the next timer clock cycle. If enabled (OCIE2 = 1), the Output Compare Flag generates an Output Compare interrupt. The OCF2 Flag is automatically cleared when the interrupt is executed. Alternatively, the OCF2 Flag can be cleared by software by writing a logical one to its I/O bit location. The waveform generator uses the match signal to generate an output according to operating mode set by the WGM21:0 bits and Compare Output mode (COM21:0) bits. The max and bottom signals are used by the waveform generator for handling the special cases of the extreme values in some modes of operation (see “Modes of Operation” on page 108). Figure 47 shows a block diagram of the Output Compare unit. Figure 47. Output Compare Unit, Block Diagram The OCR2 Register is double buffered when using any of the Pulse Width Modulation (PWM) modes. For the normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR2 Compare Register to either top or bottom of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR2 Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR2 Buffer Register, and if double buffering is disabled the CPU will access the OCR2 directly. OCFn (Int. Req.) = (8-bit Comparator ) OCRn OCxy DATA BUS TCNTn WGMn1:0 Waveform Generator TOP FOCn COMn1:0 BOTTOM106 2486AA–AVR–02/2013 ATmega8(L) Force Output Compare In non-PWM Waveform Generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC2) bit. Forcing Compare Match will not set the OCF2 Flag or reload/clear the timer, but the OC2 pin will be updated as if a real Compare Match had occurred (the COM21:0 bits settings define whether the OC2 pin is set, cleared or toggled). Compare Match Blocking by TCNT2 Write All CPU write operations to the TCNT2 Register will block any Compare Match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR2 to be initialized to the same value as TCNT2 without triggering an interrupt when the Timer/Counter clock is enabled. Using the Output Compare Unit Since writing TCNT2 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT2 when using the Output Compare channel, independently of whether the Timer/Counter is running or not. If the value written to TCNT2 equals the OCR2 value, the Compare Match will be missed, resulting in incorrect waveform generation. Similarly, do not write the TCNT2 value equal to BOTTOM when the counter is downcounting. The setup of the OC2 should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC2 value is to use the Force Output Compare (FOC2) strobe bit in Normal mode. The OC2 Register keeps its value even when changing between waveform generation modes. Be aware that the COM21:0 bits are not double buffered together with the compare value. Changing the COM21:0 bits will take effect immediately.107 2486AA–AVR–02/2013 ATmega8(L) Compare Match Output Unit The Compare Output mode (COM21:0) bits have two functions. The waveform generator uses the COM21:0 bits for defining the Output Compare (OC2) state at the next Compare Match. Also, the COM21:0 bits control the OC2 pin output source. Figure 48 shows a simplified schematic of the logic affected by the COM21:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM21:0 bits are shown. When referring to the OC2 state, the reference is for the internal OC2 Register, not the OC2 pin. Figure 48. Compare Match Output Unit, Schematic The general I/O port function is overridden by the Output Compare (OC2) from the waveform generator if either of the COM21:0 bits are set. However, the OC2 pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC2 pin (DDR_OC2) must be set as output before the OC2 value is visible on the pin. The port override function is independent of the Waveform Generation mode. The design of the Output Compare Pin logic allows initialization of the OC2 state before the output is enabled. Note that some COM21:0 bit settings are reserved for certain modes of operation. See “8-bit Timer/Counter Register Description” on page 114. PORT DDR D Q D Q OCn OCn Pin D Q Waveform Generator COMn1 COMn0 0 1 DATABUS FOCn clkI/O108 2486AA–AVR–02/2013 ATmega8(L) Compare Output Mode and Waveform Generation The Waveform Generator uses the COM21:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM21:0 = 0 tells the waveform generator that no action on the OC2 Register is to be performed on the next Compare Match. For compare output actions in the nonPWM modes refer to Table 43 on page 115. For fast PWM mode, refer to Table 44 on page 115, and for phase correct PWM refer to Table 45 on page 116. A change of the COM21:0 bits state will have effect at the first Compare Match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC2 strobe bits. Modes of Operation The mode of operation (that is, the behavior of the Timer/Counter and the Output Compare pins) is defined by the combination of the Waveform Generation mode (WGM21:0) and Compare Output mode (COM21:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM21:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM21:0 bits control whether the output should be set, cleared, or toggled at a Compare Match (see “Compare Match Output Unit” on page 107). For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 112. Normal Mode The simplest mode of operation is the Normal mode (WGM21:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV2) will be set in the same timer clock cycle as the TCNT2 becomes zero. The TOV2 Flag in this case behaves like a ninth bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV2 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Output Compare unit can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time.109 2486AA–AVR–02/2013 ATmega8(L) Clear Timer on Compare Match (CTC) Mode In Clear Timer on Compare or CTC mode (WGM21:0 = 2), the OCR2 Register is used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT2) matches the OCR2. The OCR2 defines the top value for the counter, hence also its resolution. This mode allows greater control of the Compare Match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 49. The counter value (TCNT2) increases until a Compare Match occurs between TCNT2 and OCR2, and then counter (TCNT2) is cleared. Figure 49. CTC Mode, Timing Diagram An interrupt can be generated each time the counter value reaches the TOP value by using the OCF2 Flag. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR2 is lower than the current value of TCNT2, the counter will miss the Compare Match. The counter will then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the Compare Match can occur. For generating a waveform output in CTC mode, the OC2 output can be set to toggle its logical level on each Compare Match by setting the Compare Output mode bits to toggle mode (COM21:0 = 1). The OC2 value will not be visible on the port pin unless the data direction for the pin is set to output. The waveform generated will have a maximum frequency of fOC2 = fclk_I/O/2 when OCR2 is set to zero (0x00). The waveform frequency is defined by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). As for the Normal mode of operation, the TOV2 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x00. TCNTn OCn (Toggle) OCn Interrupt Flag Set Period 1 2 3 4 (COMn1:0 = 1) f OCn f clk_I/O 2   N   1 + OCRn = ----------------------------------------------110 2486AA–AVR–02/2013 ATmega8(L) Fast PWM Mode The fast Pulse Width Modulation or fast PWM mode (WGM21:0 = 3) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM option by its single-slope operation. The counter counts from BOTTOM to MAX then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OC2) is cleared on the Compare Match between TCNT2 and OCR2, and set at BOTTOM. In inverting Compare Output mode, the output is set on Compare Match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct PWM mode that uses dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), and therefore reduces total system cost. In fast PWM mode, the counter is incremented until the counter value matches the MAX value. The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 50. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2 and TCNT2. Figure 50. Fast PWM Mode, Timing Diagram The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches MAX. If the interrupt is enabled, the interrupt handler routine can be used for updating the compare value. In fast PWM mode, the compare unit allows generation of PWM waveforms on the OC2 pin. Setting the COM21:0 bits to 2 will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM21:0 to 3 (see Table 44 on page 115). The actual OC2 value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by setting (or clearing) the OC2 Register at the Compare Match between OCR2 and TCNT2, and clearing (or setting) the OC2 Register at the timer clock cycle the counter is cleared (changes from MAX to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). TCNTn OCRn Update and TOVn Interrupt Flag Set Period 1 2 3 OCn OCn (COMn1:0 = 2) (COMn1:0 = 3) OCRn Interrupt Flag Set 4 5 6 7 f OCnPWM f clk_I/O N  256 = ------------------111 2486AA–AVR–02/2013 ATmega8(L) The extreme values for the OCR2 Register represent special cases when generating a PWM waveform output in the fast PWM mode. If the OCR2 is set equal to BOTTOM, the output will be a narrow spike for each MAX+1 timer clock cycle. Setting the OCR2 equal to MAX will result in a constantly high or low output (depending on the polarity of the output set by the COM21:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC2 to toggle its logical level on each Compare Match (COM21:0 = 1). The waveform generated will have a maximum frequency of foc2 = fclk_I/O/2 when OCR2 is set to zero. This feature is similar to the OC2 toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. Phase Correct PWM Mode The phase correct PWM mode (WGM21:0 = 1) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is based on a dual-slope operation. The counter counts repeatedly from BOTTOM to MAX and then from MAX to BOTTOM. In noninverting Compare Output mode, the Output Compare (OC2) is cleared on the Compare Match between TCNT2 and OCR2 while upcounting, and set on the Compare Match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode is fixed to eight bits. In phase correct PWM mode the counter is incremented until the counter value matches MAX. When the counter reaches MAX, it changes the count direction. The TCNT2 value will be equal to MAX for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 51. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2 and TCNT2. Figure 51. Phase Correct PWM Mode, Timing Diagram TOVn Interrupt Flag Set OCn Interrupt Flag Set 1 2 3 TCNTn Period OCn OCn (COMn1:0 = 2) (COMn1:0 = 3) OCRn Update112 2486AA–AVR–02/2013 ATmega8(L) The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches BOTTOM. The Interrupt Flag can be used to generate an interrupt each time the counter reaches the BOTTOM value. In phase correct PWM mode, the compare unit allows generation of PWM waveforms on the OC2 pin. Setting the COM21:0 bits to 2 will produce a non-inverted PWM. An inverted PWM output can be generated by setting the COM21:0 to 3 (see Table 45 on page 116). The actual OC2 value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by clearing (or setting) the OC2 Register at the Compare Match between OCR2 and TCNT2 when the counter increments, and setting (or clearing) the OC2 Register at Compare Match between OCR2 and TCNT2 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2 Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR2 is set equal to BOTTOM, the output will be continuously low and if set equal to MAX the output will be continuously high for noninverted PWM mode. For inverted PWM the output will have the opposite logic values. At the very start of period 2 in Figure 51 on page 111 OCn has a transition from high to low even though there is no Compare Match. The point of this transition is to guarantee symmetry around BOTTOM. There are two cases that give a transition without Compare Match: • OCR2A changes its value from MAX, like in Figure 51 on page 111. When the OCR2A value is MAX the OCn pin value is the same as the result of a down-counting Compare Match. To ensure symmetry around BOTTOM the OCn value at MAX must correspond to the result of an up-counting Compare Match • The timer starts counting from a value higher than the one in OCR2A, and for that reason misses the Compare Match and hence the OCn change that would have happened on the way up Timer/Counter Timing Diagrams The following figures show the Timer/Counter in Synchronous mode, and the timer clock (clkT2) is therefore shown as a clock enable signal. In Asynchronous mode, clkI/O should be replaced by the Timer/Counter Oscillator clock. The figures include information on when Interrupt Flags are set. Figure 52 contains timing data for basic Timer/Counter operation. The figure shows the count sequence close to the MAX value in all modes other than phase correct PWM mode. Figure 52. Timer/Counter Timing Diagram, no Prescaling f OCnPCPWM f clk_I/O N  510 = ------------------ clkTn (clkI/O/1) TOVn clkI/O TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1113 2486AA–AVR–02/2013 ATmega8(L) Figure 53 shows the same timing data, but with the prescaler enabled. Figure 53. Timer/Counter Timing Diagram, with Prescaler (fclk_I/O/8) Figure 54 shows the setting of OCF2 in all modes except CTC mode. Figure 54. Timer/Counter Timing Diagram, Setting of OCF2, with Prescaler (fclk_I/O/8) TOVn TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) OCFn OCRn TCNTn OCRn Value OCRn - 1 OCRn OCRn + 1 OCRn + 2 clkI/O clkTn (clkI/O/8)114 2486AA–AVR–02/2013 ATmega8(L) Figure 55 shows the setting of OCF2 and the clearing of TCNT2 in CTC mode. Figure 55. Timer/Counter Timing Diagram, Clear Timer on Compare Match Mode, with Prescaler (fclk_I/O/8) 8-bit Timer/Counter Register Description Timer/Counter Control Register – TCCR2 • Bit 7 – FOC2: Force Output Compare The FOC2 bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2 is written when operating in PWM mode. When writing a logical one to the FOC2 bit, an immediate Compare Match is forced on the waveform generation unit. The OC2 output is changed according to its COM21:0 bits setting. Note that the FOC2 bit is implemented as a strobe. Therefore it is the value present in the COM21:0 bits that determines the effect of the forced compare. A FOC2 strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2 as TOP. The FOC2 bit is always read as zero. • Bit 6:3 – WGM21:0: Waveform Generation Mode These bits control the counting sequence of the counter, the source for the maximum (TOP) counter value, and what type of waveform generation to be used. Modes of operation supported by the Timer/Counter unit are: Normal mode, Clear Timer on Compare Match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes. See Table 42 on page 115 and “Modes of Operation” on page 108. OCFn OCRn TCNTn (CTC) TOP TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) Bit 7 6 5 4 3 2 1 0 FOC2 WGM20 COM21 COM20 WGM21 CS22 CS21 CS20 TCCR2 Read/Write W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0115 2486AA–AVR–02/2013 ATmega8(L) Note: 1. The CTC2 and PWM2 bit definition names are now obsolete. Use the WGM21:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer • Bit 5:4 – COM21:0: Compare Match Output Mode These bits control the Output Compare Pin (OC2) behavior. If one or both of the COM21:0 bits are set, the OC2 output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to OC2 pin must be set in order to enable the output driver. When OC2 is connected to the pin, the function of the COM21:0 bits depends on the WGM21:0 bit setting. Table 43 shows the COM21:0 bit functionality when the WGM21:0 bits are set to a normal or CTC mode (non-PWM). Table 44 shows the COM21:0 bit functionality when the WGM21:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR2 equals TOP and COM21 is set. In this case, the Compare Match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on page 110 for more details Table 42. Waveform Generation Mode Bit Description Mode WGM21 (CTC2) WGM20 (PWM2) Timer/Counter Mode of Operation(1) TOP Update of OCR2 TOV2 Flag Set 0 0 0 Normal 0xFF Immediate MAX 1 0 1 PWM, Phase Correct 0xFF TOP BOTTOM 2 1 0 CTC OCR2 Immediate MAX 3 1 1 Fast PWM 0xFF BOTTOM MAX Table 43. Compare Output Mode, Non-PWM Mode COM21 COM20 Description 0 0 Normal port operation, OC2 disconnected 0 1 Toggle OC2 on Compare Match 1 0 Clear OC2 on Compare Match 1 1 Set OC2 on Compare Match Table 44. Compare Output Mode, Fast PWM Mode(1) COM21 COM20 Description 0 0 Normal port operation, OC2 disconnected 0 1 Reserved 1 0 Clear OC2 on Compare Match, set OC2 at BOTTOM, (non-inverting mode) 1 1 Set OC2 on Compare Match, clear OC2 at BOTTOM, (inverting mode)116 2486AA–AVR–02/2013 ATmega8(L) Table 45 shows the COM21:0 bit functionality when the WGM21:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2 equals TOP and COM21 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase Correct PWM Mode” on page 111 for more details • Bit 2:0 – CS22:0: Clock Select The three clock select bits select the clock source to be used by the Timer/Counter, see Table 46. Timer/Counter Register – TCNT2 The Timer/Counter Register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the Compare Match on the following timer clock. Modifying the counter (TCNT2) while the counter is running, introduces a risk of missing a Compare Match between TCNT2 and the OCR2 Register. Output Compare Register – OCR2 The Output Compare Register contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2 pin. Table 45. Compare Output Mode, Phase Correct PWM Mode(1) COM21 COM20 Description 0 0 Normal port operation, OC2 disconnected 0 1 Reserved 1 0 Clear OC2 on Compare Match when up-counting. Set OC2 on Compare Match when downcounting 1 1 Set OC2 on Compare Match when up-counting. Clear OC2 on Compare Match when downcounting Table 46. Clock Select Bit Description CS22 CS21 CS20 Description 0 0 0 No clock source (Timer/Counter stopped) 0 0 1 clkT2S/(No prescaling) 0 1 0 clkT2S/8 (From prescaler) 0 1 1 clkT2S/32 (From prescaler) 1 0 0 clkT2S/64 (From prescaler) 1 0 1 clkT2S/128 (From prescaler) 1 1 0 clkT2S/256 (From prescaler) 1 1 1 clkT2S/1024 (From prescaler) Bit 7 6 5 4 3 2 1 0 TCNT2[7:0] TCNT2 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR2[7:0] OCR2 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0117 2486AA–AVR–02/2013 ATmega8(L) Asynchronous Operation of the Timer/Counter Asynchronous Status Register – ASSR • Bit 3 – AS2: Asynchronous Timer/Counter2 When AS2 is written to zero, Timer/Counter 2 is clocked from the I/O clock, clkI/O. When AS2 is written to one, Timer/Counter 2 is clocked from a crystal Oscillator connected to the Timer Oscillator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of TCNT2, OCR2, and TCCR2 might be corrupted. • Bit 2 – TCN2UB: Timer/Counter2 Update Busy When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set. When TCNT2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value. • Bit 1 – OCR2UB: Output Compare Register2 Update Busy When Timer/Counter2 operates asynchronously and OCR2 is written, this bit becomes set. When OCR2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2 is ready to be updated with a new value. • Bit 0 – TCR2UB: Timer/Counter Control Register2 Update Busy When Timer/Counter2 operates asynchronously and TCCR2 is written, this bit becomes set. When TCCR2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2 is ready to be updated with a new value. If a write is performed to any of the three Timer/Counter2 Registers while its update busy flag is set, the updated value might get corrupted and cause an unintentional interrupt to occur. The mechanisms for reading TCNT2, OCR2, and TCCR2 are different. When reading TCNT2, the actual timer value is read. When reading OCR2 or TCCR2, the value in the temporary storage register is read. Asynchronous Operation of Timer/Counter2 When Timer/Counter2 operates asynchronously, some considerations must be taken. • Warning: When switching between asynchronous and synchronous clocking of Timer/Counter2, the Timer Registers TCNT2, OCR2, and TCCR2 might be corrupted. A safe procedure for switching clock source is: 1. Disable the Timer/Counter2 interrupts by clearing OCIE2 and TOIE2 2. Select clock source by setting AS2 as appropriate 3. Write new values to TCNT2, OCR2, and TCCR2 4. To switch to asynchronous operation: Wait for TCN2UB, OCR2UB, and TCR2UB 5. Clear the Timer/Counter2 Interrupt Flags 6. Enable interrupts, if needed • The Oscillator is optimized for use with a 32.768kHz watch crystal. Applying an external clock to the TOSC1 pin may result in incorrect Timer/Counter2 operation. The CPU main clock frequency must be more than four times the Oscillator frequency • When writing to one of the registers TCNT2, OCR2, or TCCR2, the value is transferred to a temporary register, and latched after two positive edges on TOSC1. The user should not Bit 7 6 5 4 3 2 1 0 – – – – AS2 TCN2UB OCR2UB TCR2UB ASSR Read/Write R R R R R/W R R R Initial Value 0 0 0 0 0 0 0 0118 2486AA–AVR–02/2013 ATmega8(L) write a new value before the contents of the temporary register have been transferred to its destination. Each of the three mentioned registers have their individual temporary register, which means that, for example, writing to TCNT2 does not disturb an OCR2 write in progress. To detect that a transfer to the destination register has taken place, the Asynchronous Status Register – ASSR has been implemented • When entering Power-save mode after having written to TCNT2, OCR2, or TCCR2, the user must wait until the written register has been updated if Timer/Counter2 is used to wake up the device. Otherwise, the MCU will enter sleep mode before the changes are effective. This is particularly important if the Output Compare2 interrupt is used to wake up the device, since the Output Compare function is disabled during writing to OCR2 or TCNT2. If the write cycle is not finished, and the MCU enters sleep mode before the OCR2UB bit returns to zero, the device will never receive a Compare Match interrupt, and the MCU will not wake up • If Timer/Counter2 is used to wake the device up from Power-save mode, precautions must be taken if the user wants to re-enter one of these modes: The interrupt logic needs one TOSC1 cycle to be reset. If the time between wake-up and re-entering sleep mode is less than one TOSC1 cycle, the interrupt will not occur, and the device will fail to wake up. If the user is in doubt whether the time before re-entering Power-save or Extended Standby mode is sufficient, the following algorithm can be used to ensure that one TOSC1 cycle has elapsed: 1. Write a value to TCCR2, TCNT2, or OCR2 2. Wait until the corresponding Update Busy Flag in ASSR returns to zero 3. Enter Power-save or Extended Standby mode • When the asynchronous operation is selected, the 32.768kHZ Oscillator for Timer/Counter2 is always running, except in Power-down and Standby modes. After a Power-up Reset or Wake-up from Power-down or Standby mode, the user should be aware of the fact that this Oscillator might take as long as one second to stabilize. The user is advised to wait for at least one second before using Timer/Counter2 after Power-up or Wake-up from Power-down or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after a wake-up from Power-down or Standby mode due to unstable clock signal upon startup, no matter whether the Oscillator is in use or a clock signal is applied to the TOSC1 pin • Description of wake up from Power-save or Extended Standby mode when the timer is clocked asynchronously: When the interrupt condition is met, the wake up process is started on the following cycle of the timer clock, that is, the timer is always advanced by at least one before the processor can read the counter value. After wake-up, the MCU is halted for four cycles, it executes the interrupt routine, and resumes execution from the instruction following SLEEP • Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect result. Since TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be done through a register synchronized to the internal I/O clock domain. Synchronization takes place for every rising TOSC1 edge. When waking up from Powersave mode, and the I/O clock (clkI/O) again becomes active, TCNT2 will read as the previous value (before entering sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after waking up from Power-save mode is essentially unpredictable, as it depends on the wake-up time. The recommended procedure for reading TCNT2 is thus as follows: 1. Write any value to either of the registers OCR2 or TCCR2 2. Wait for the corresponding Update Busy Flag to be cleared 3. Read TCNT2119 2486AA–AVR–02/2013 ATmega8(L) • During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous timer takes three processor cycles plus one timer cycle. The timer is therefore advanced by at least one before the processor can read the timer value causing the setting of the Interrupt Flag. The Output Compare Pin is changed on the timer clock and is not synchronized to the processor clock Timer/Counter Interrupt Mask Register – TIMSK • Bit 7 – OCIE2: Timer/Counter2 Output Compare Match Interrupt Enable When the OCIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match interrupt is enabled. The corresponding interrupt is executed if a Compare Match in Timer/Counter2 occurs (that is, when the OCF2 bit is set in the Timer/Counter Interrupt Flag Register – TIFR). • Bit 6 – TOIE2: Timer/Counter2 Overflow Interrupt Enable When the TOIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter2 occurs (that is, when the TOV2 bit is set in the Timer/Counter Interrupt Flag Register – TIFR). Timer/Counter Interrupt Flag Register – TIFR • Bit 7 – OCF2: Output Compare Flag 2 The OCF2 bit is set (one) when a Compare Match occurs between the Timer/Counter2 and the data in OCR2 – Output Compare Register2. OCF2 is cleared by hardware when executing the corresponding interrupt Handling Vector. Alternatively, OCF2 is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2 (Timer/Counter2 Compare Match Interrupt Enable), and OCF2 are set (one), the Timer/Counter2 Compare Match Interrupt is executed. • Bit 6 – TOV2: Timer/Counter2 Overflow Flag The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when executing the corresponding interrupt Handling Vector. Alternatively, TOV2 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE2 (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter2 changes counting direction at 0x00. Bit 7 6 5 4 3 2 1 0 OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 TIMSK Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 TIFR Read/Write R/W R/W R/W R/W R/W R/W R R/W Initial Value 0 0 0 0 0 0 0 0120 2486AA–AVR–02/2013 ATmega8(L) Timer/Counter Prescaler Figure 56. Prescaler for Timer/Counter2 The clock source for Timer/Counter2 is named clkT2S. clkT2S is by default connected to the main system I/O clock clkI/O. By setting the AS2 bit in ASSR, Timer/Counter2 is asynchronously clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real Time Counter (RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from Port B. A crystal can then be connected between the TOSC1 and TOSC2 pins to serve as an independent clock source for Timer/Counter2. The Oscillator is optimized for use with a 32.768kHz crystal. Applying an external clock source to TOSC1 is not recommended. For Timer/Counter2, the possible prescaled selections are: clkT2S/8, clkT2S/32, clkT2S/64, clkT2S/128, clkT2S/256, and clkT2S/1024. Additionally, clkT2S as well as 0 (stop) may be selected. Setting the PSR2 bit in SFIOR resets the prescaler. This allows the user to operate with a predictable prescaler. Special Function IO Register – SFIOR • Bit 1 – PSR2: Prescaler Reset Timer/Counter2 When this bit is written to one, the Timer/Counter2 prescaler will be reset. The bit will be cleared by hardware after the operation is performed. Writing a zero to this bit will have no effect. This bit will always be read as zero if Timer/Counter2 is clocked by the internal CPU clock. If this bit is written when Timer/Counter2 is operating in Asynchronous mode, the bit will remain one until the prescaler has been reset. 10-BIT T/C PRESCALER TIMER/COUNTER2 CLOCK SOURCE clkI/O clkT2S TOSC1 AS2 CS20 CS21 CS22 clkT2S/8 clkT2S/64 clkT2S/128 clkT2S/1024 clkT2S/256 clkT2S/32 0 PSR2 Clear clkT2 Bit 7 6 5 4 3 2 1 0 – – – – ACME PUD PSR2 PSR10 SFIOR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0121 2486AA–AVR–02/2013 ATmega8(L) Serial Peripheral Interface – SPI The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the ATmega8 and peripheral devices or between several AVR devices. The ATmega8 SPI includes the following features: • Full-duplex, Three-wire Synchronous Data Transfer • Master or Slave Operation • LSB First or MSB First Data Transfer • Seven Programmable Bit Rates • End of Transmission Interrupt Flag • Write Collision Flag Protection • Wake-up from Idle Mode • Double Speed (CK/2) Master SPI Mode Figure 57. SPI Block Diagram(1) Note: 1. Refer to “Pin Configurations” on page 2, and Table 22 on page 58 for SPI pin placement The interconnection between Master and Slave CPUs with SPI is shown in Figure 58 on page 122. The system consists of two Shift Registers, and a Master clock generator. The SPI Master initiates the communication cycle when pulling low the Slave Select SS pin of the desired Slave. Master and Slave prepare the data to be sent in their respective Shift Registers, and the Master generates the required clock pulses on the SCK line to interchange data. Data is always shifted from Master to Slave on the Master Out – Slave In, MOSI, line, and from Slave to Master on the Master In – Slave Out, MISO, line. After each data packet, the Master will synchronize the Slave by pulling high the Slave Select, SS, line. When configured as a Master, the SPI interface has no automatic control of the SS line. This must be handled by user software before communication can start. When this is done, writing a SPI2X SPI2X DIVIDER /2/4/8/16/32/64/128122 2486AA–AVR–02/2013 ATmega8(L) byte to the SPI Data Register starts the SPI clock generator, and the hardware shifts the eight bits into the Slave. After shifting one byte, the SPI clock generator stops, setting the end of Transmission Flag (SPIF). If the SPI interrupt enable bit (SPIE) in the SPCR Register is set, an interrupt is requested. The Master may continue to shift the next byte by writing it into SPDR, or signal the end of packet by pulling high the Slave Select, SS line. The last incoming byte will be kept in the Buffer Register for later use. When configured as a Slave, the SPI interface will remain sleeping with MISO tri-stated as long as the SS pin is driven high. In this state, software may update the contents of the SPI Data Register, SPDR, but the data will not be shifted out by incoming clock pulses on the SCK pin until the SS pin is driven low. As one byte has been completely shifted, the end of Transmission Flag, SPIF is set. If the SPI interrupt enable bit, SPIE, in the SPCR Register is set, an interrupt is requested. The Slave may continue to place new data to be sent into SPDR before reading the incoming data. The last incoming byte will be kept in the Buffer Register for later use. Figure 58. SPI Master-Slave Interconnection The system is single buffered in the transmit direction and double buffered in the receive direction. This means that bytes to be transmitted cannot be written to the SPI Data Register before the entire shift cycle is completed. When receiving data, however, a received character must be read from the SPI Data Register before the next character has been completely shifted in. Otherwise, the first byte is lost. In SPI Slave mode, the control logic will sample the incoming signal of the SCK pin. To ensure correct sampling of the clock signal, the minimum low and high periods should be: Low period: longer than 2 CPU clock cycles High period: longer than 2 CPU clock cycles When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden according to Table 47. For more details on automatic port overrides, refer to “Alternate Port Functions” on page 56. Note: 1. See “Port B Pins Alternate Functions” on page 58 for a detailed description of how to define the direction of the user defined SPI pins Table 47. SPI Pin Overrides(1) Pin Direction, Master SPI Direction, Slave SPI MOSI User Defined Input MISO Input User Defined SCK User Defined Input SS User Defined Input MSB MASTER LSB 8 BIT SHIFT REGISTER MSB SLAVE LSB 8 BIT SHIFT REGISTER MISO MOSI SPI CLOCK GENERATOR SCK SS MISO MOSI SCK SS VCC SHIFT ENABLE123 2486AA–AVR–02/2013 ATmega8(L) The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. For example if MOSI is placed on pin PB5, replace DD_MOSI with DDB5 and DDR_SPI with DDRB. Note: 1. See “About Code Examples” on page 8 Assembly Code Example(1) SPI_MasterInit: ; Set MOSI and SCK output, all others input ldi r17,(1<>8); UBRRL = (unsigned char)ubrr; /* Enable receiver and transmitter */ UCSRB = (1<> 1) & 0x01; return ((resh << 8) | resl); }141 2486AA–AVR–02/2013 ATmega8(L) Receive Compete Flag and Interrupt The USART Receiver has one flag that indicates the Receiver state. The Receive Complete (RXC) Flag indicates if there are unread data present in the receive buffer. This flag is one when unread data exist in the receive buffer, and zero when the receive buffer is empty (that is, does not contain any unread data). If the Receiver is disabled (RXEN = 0), the receive buffer will be flushed and consequently the RXC bit will become zero. When the Receive Complete Interrupt Enable (RXCIE) in UCSRB is set, the USART Receive Complete Interrupt will be executed as long as the RXC Flag is set (provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDR in order to clear the RXC Flag, otherwise a new interrupt will occur once the interrupt routine terminates. Receiver Error Flags The USART Receiver has three error flags: Frame Error (FE), Data OverRun (DOR) and Parity Error (PE). All can be accessed by reading UCSRA. Common for the error flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the error flags, the UCSRA must be read before the receive buffer (UDR), since reading the UDR I/O location changes the buffer read location. Another equality for the error flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRA is written for upward compatibility of future USART implementations. None of the error flags can generate interrupts. The Frame Error (FE) Flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FE Flag is zero when the stop bit was correctly read (as one), and the FE Flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FE Flag is not affected by the setting of the USBS bit in UCSRC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRA. The Data OverRun (DOR) Flag indicates data loss due to a Receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DOR Flag is set there was one or more serial frame lost between the frame last read from UDR, and the next frame read from UDR. For compatibility with future devices, always write this bit to zero when writing to UCSRA. The DOR Flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (PE) Flag indicates that the next frame in the receive buffer had a parity error when received. If parity check is not enabled the PE bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRA. For more details see “Parity Bit Calculation” on page 134 and “Parity Checker” . Parity Checker The Parity Checker is active when the high USART Parity mode (UPM1) bit is set. Type of parity check to be performed (odd or even) is selected by the UPM0 bit. When enabled, the Parity Checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error (PE) Flag can then be read by software to check if the frame had a parity error. The PE bit is set if the next character that can be read from the receive buffer had a parity error when received and the parity checking was enabled at that point (UPM1 = 1). This bit is valid until the receive buffer (UDR) is read.142 2486AA–AVR–02/2013 ATmega8(L) Disabling the Receiver In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing receptions will therefore be lost. When disabled (that is, the RXEN is set to zero) the Receiver will no longer override the normal function of the RxD port pin. The Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in the buffer will be lost Flushing the Receive Buffer The Receiver buffer FIFO will be flushed when the Receiver is disabled (that is, the buffer will be emptied of its contents). Unread data will be lost. If the buffer has to be flushed during normal operation, due to for instance an error condition, read the UDR I/O location until the RXC Flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See “About Code Examples” on page 8 Asynchronous Data Reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxD pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the Receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. Asynchronous Clock Recovery The clock recovery logic synchronizes internal clock to the incoming serial frames. Figure 65 illustrates the sampling process of the start bit of an incoming frame. The sample rate is 16 times the baud rate for Normal mode, and eight times the baud rate for Double Speed mode. The horizontal arrows illustrate the synchronization variation due to the sampling process. Note the larger time variation when using the Double Speed mode (U2X = 1) of operation. Samples denoted zero are samples done when the RxD line is idle (that is, no communication activity). Figure 65. Start Bit Sampling When the clock recovery logic detects a high (idle) to low (start) transition on the RxD line, the start bit detection sequence is initiated. Let sample 1 denote the first zero-sample as shown in Assembly Code Example(1) USART_Flush: sbis UCSRA, RXC ret in r16, UDR rjmp USART_Flush C Code Example(1) void USART_Flush( void ) { unsigned char dummy; while ( UCSRA & (1< 2 CPU clock cycles for fck <12MHz, 3 CPU clock cycles for fck >=12MHz High:> 2 CPU clock cycles for fck <12MHz, 3 CPU clock cycles for fck >=12MHz Table 96. Pin Mapping Serial Programming Symbol Pins I/O Description MOSI PB3 I Serial data in MISO PB4 O Serial data out SCK PB5 I Serial clock VCC GND XTAL1 SCK MISO MOSI RESET PB3 PB4 PB5 +2.7V - 5.5V AVCC +2.7V - 5.5V (2)231 2486AA–AVR–02/2013 ATmega8(L) Serial Programming Algorithm When writing serial data to the ATmega8, data is clocked on the rising edge of SCK. When reading data from the ATmega8, data is clocked on the falling edge of SCK. See Figure 113 on page 232 for timing details. To program and verify the ATmega8 in the Serial Programming mode, the following sequence is recommended (see four byte instruction formats in Table 98 on page 233): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to “0”. In some systems, the programmer can not guarantee that SCK is held low during Power-up. In this case, RESET must be given a positive pulse of at least two CPU clock cycles duration after SCK has been set to “0” 2. Wait for at least 20ms and enable Serial Programming by sending the Programming Enable serial instruction to pin MOSI 3. The Serial Programming instructions will not work if the communication is out of synchronization. When in sync. the second byte (0x53), will echo back when issuing the third byte of the Programming Enable instruction. Whether the echo is correct or not, all four bytes of the instruction must be transmitted. If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command 4. The Flash is programmed one page at a time. The page size is found in Table 89 on page 218. The memory page is loaded one byte at a time by supplying the 5 LSB of the address and data together with the Load Program memory Page instruction. To ensure correct loading of the page, the data Low byte must be loaded before data High byte is applied for a given address. The Program memory Page is stored by loading the Write Program memory Page instruction with the 7MSB of the address. If polling is not used, the user must wait at least tWD_FLASH before issuing the next page (see Table 97 on page 232). Note: If other commands than polling (read) are applied before any write operation (FLASH, EEPROM, Lock Bits, Fuses) is completed, it may result in incorrect programming 5. The EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. If polling is not used, the user must wait at least tWD_EEPROM before issuing the next byte (see Table 97 on page 232). In a chip erased device, no 0xFFs in the data file(s) need to be programmed 6. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO 7. At the end of the programming session, RESET can be set high to commence normal operation 8. Power-off sequence (if needed): Set RESET to “1” Turn VCC power off Data Polling Flash When a page is being programmed into the Flash, reading an address location within the page being programmed will give the value 0xFF. At the time the device is ready for a new page, the programmed value will read correctly. This is used to determine when the next page can be written. Note that the entire page is written simultaneously and any address within the page can be used for polling. Data polling of the Flash will not work for the value 0xFF, so when programming this value, the user will have to wait for at least tWD_FLASH before programming the next page. As a chip-erased device contains 0xFF in all locations, programming of addresses that are meant to contain 0xFF, can be skipped. See Table 97 on page 232 for tWD_FLASH value.232 2486AA–AVR–02/2013 ATmega8(L) Data Polling EEPROM When a new byte has been written and is being programmed into EEPROM, reading the address location being programmed will give the value 0xFF. At the time the device is ready for a new byte, the programmed value will read correctly. This is used to determine when the next byte can be written. This will not work for the value 0xFF, but the user should have the following in mind: As a chip-erased device contains 0xFF in all locations, programming of addresses that are meant to contain 0xFF, can be skipped. This does not apply if the EEPROM is Re-programmed without chip-erasing the device. In this case, data polling cannot be used for the value 0xFF, and the user will have to wait at least tWD_EEPROM before programming the next byte. See Table 97 for tWD_EEPROM value. Figure 113. Serial Programming Waveforms Table 97. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location Symbol Minimum Wait Delay tWD_FUSE 4.5ms tWD_FLASH 4.5ms tWD_EEPROM 9.0ms tWD_ERASE 9.0ms MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUT233 2486AA–AVR–02/2013 ATmega8(L) Note: a = address high bits b = address low bits H = 0 – Low byte, 1 – High byte o = data out i = data in x = don’t care Table 98. Serial Programming Instruction Set Instruction Instruction Format Byte 1 Byte 2 Byte 3 Byte 4 Operation Programming Enable 1010 1100 0101 0011 xxxx xxxx xxxx xxxx Enable Serial Programming after RESET goes low Chip Erase 1010 1100 100x xxxx xxxx xxxx xxxx xxxx Chip Erase EEPROM and Flash Read Program Memory 0010 H000 0000 aaaa bbbb bbbb oooo oooo Read H (high or low) data o from Program memory at word address a:b Load Program Memory Page 0100 H000 0000 xxxx xxxb bbbb iiii iiii Write H (high or low) data i to Program memory page at word address b. Data Low byte must be loaded before Data High byte is applied within the same address Write Program Memory Page 0100 1100 0000 aaaa bbbx xxxx xxxx xxxx Write Program memory Page at address a:b Read EEPROM Memory 1010 0000 00xx xxxa bbbb bbbb oooo oooo Read data o from EEPROM memory at address a:b Write EEPROM Memory 1100 0000 00xx xxxa bbbb bbbb iiii iiii Write data i to EEPROM memory at address a:b Read Lock Bits 0101 1000 0000 0000 xxxx xxxx xxoo oooo Read Lock Bits. “0” = programmed, “1” = unprogrammed. See Table 85 on page 215 for details Write Lock Bits 1010 1100 111x xxxx xxxx xxxx 11ii iiii Write Lock Bits. Set bits = “0” to program Lock Bits. See Table 85 on page 215 for details Read Signature Byte 0011 0000 00xx xxxx xxxx xxbb oooo oooo Read Signature Byte o at address b Write Fuse Bits 1010 1100 1010 0000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. See Table 88 on page 217 for details Write Fuse High Bits 1010 1100 1010 1000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. See Table 87 on page 216 for details Read Fuse Bits 0101 0000 0000 0000 xxxx xxxx oooo oooo Read Fuse Bits. “0” = programmed, “1” = unprogrammed. See Table 88 on page 217 for details Read Fuse High Bits 0101 1000 0000 1000 xxxx xxxx oooo oooo Read Fuse high bits. “0” = programmed, “1” = unprogrammed. See Table 87 on page 216 for details Read Calibration Byte 0011 1000 00xx xxxx 0000 00bb oooo oooo Read Calibration Byte234 2486AA–AVR–02/2013 ATmega8(L) SPI Serial Programming Characteristics For characteristics of the SPI module, see “SPI Timing Characteristics” on page 239.235 2486AA–AVR–02/2013 ATmega8(L) Electrical Characteristics – TA = -40°C to 85°C Note: Typical values contained in this datasheet are based on simulations and characterization of other AVR microcontrollers manufactured on the same process technology. Min and Max values will be available after the device is characterized. DC Characteristics Absolute Maximum Ratings* Operating Temperature.................................. -55C to +125C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ................................................ 40.0mA DC Current VCC and GND Pins................................. 300.0mA TA = -40C to +85C, VCC = 2.7V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min Typ Max Units VIL Input Low Voltage except XTAL1 and RESET pins VCC = 2.7V - 5.5V -0.5 0.2 VCC(1) V VIH Input High Voltage except XTAL1 and RESET pins VCC = 2.7V - 5.5V 0.6VCC(2) VCC + 0.5 VIL1 Input Low Voltage XTAL1 pin VCC = 2.7V - 5.5V -0.5 0.1VCC(1) VIH1 Input High Voltage XTAL 1 pin VCC = 2.7V - 5.5V 0.8VCC(2) VCC + 0.5 VIL2 Input Low Voltage RESET pin VCC = 2.7V - 5.5V -0.5 0.2 VCC VIH2 Input High Voltage RESET pin VCC = 2.7V - 5.5V 0.9VCC(2) VCC + 0.5 VIL3 Input Low Voltage RESET pin as I/O VCC = 2.7V - 5.5V -0.5 0.2VCC VIH3 Input High Voltage RESET pin as I/O VCC = 2.7V - 5.5V 0.6VCC(2) 0.7VCC(2) VCC + 0.5 VOL Output Low Voltage(3) (Ports B,C,D) I OL = 20mA, VCC = 5V IOL = 10mA, VCC = 3V 0.9 0.6 VOH Output High Voltage(4) (Ports B,C,D) I OH = -20mA, VCC = 5V IOH = -10mA, VCC = 3V 4.2 2.2 IIL Input Leakage Current I/O Pin Vcc = 5.5V, pin low (absolute value) 1 µA I IH Input Leakage Current I/O Pin Vcc = 5.5V, pin high (absolute value) 1 RRST Reset Pull-up Resistor 30 80 k236 2486AA–AVR–02/2013 ATmega8(L) Notes: 1. “Max” means the highest value where the pin is guaranteed to be read as low 2. “Min” means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP, TQFP, and QFN/MLF Package: 1] The sum of all IOL, for all ports, should not exceed 300mA. 2] The sum of all IOL, for ports C0 - C5 should not exceed 100mA. 3] The sum of all IOL, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 200mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition 4. Although each I/O port can source more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP, TQFP, and QFN/MLF Package: 1] The sum of all IOH, for all ports, should not exceed 300mA. 2] The sum of all IOH, for port C0 - C5, should not exceed 100mA. 3] The sum of all IOH, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 200mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition 5. Minimum VCC for Power-down is 2.5V Rpu I/O Pin Pull-up Resistor 20 50 k ICC Power Supply Current Active 4MHz, VCC = 3V (ATmega8L) 3 5 mA Active 8MHz, VCC = 5V (ATmega8) 11 15 Idle 4MHz, VCC = 3V (ATmega8L) 1 2 Idle 8MHz, VCC = 5V (ATmega8) 4.5 7 Power-down mode(5) WDT enabled, VCC = 3V < 22 28 µA WDT disabled, VCC = 3V < 1 3 VACIO Analog Comparator Input Offset Voltage VCC = 5V Vin = VCC/2 40 mV IACLK Analog Comparator Input Leakage Current VCC = 5V Vin = VCC/2 -50 50 nA tACPD Analog Comparator Propagation Delay VCC = 2.7V VCC = 5.0V 750 500 ns TA = -40C to +85C, VCC = 2.7V to 5.5V (unless otherwise noted) (Continued) Symbol Parameter Condition Min Typ Max Units237 2486AA–AVR–02/2013 ATmega8(L) External Clock Drive Waveforms Figure 114. External Clock Drive Waveforms External Clock Drive Notes: 1. R should be in the range 3k - 100k, and C should be at least 20pF. The C values given in the table includes pin capacitance. This will vary with package type 2. The frequency will vary with package type and board layout VIL1 VIH1 Table 99. External Clock Drive Symbol Parameter VCC = 2.7V to 5.5V VCC = 4.5V to 5.5V Min Max Min Max Units 1/tCLCL Oscillator Frequency 0 8 0 16 MHz tCLCL Clock Period 125 62.5 tCHCX High Time 50 25 ns tCLCX Low Time 50 25 tCLCH Rise Time 1.6 0.5 s tCHCL Fall Time 1.6 0.5 tCLCL Change in period from one clock cycle to the next 2 2% Table 100. External RC Oscillator, Typical Frequencies R [k] (1) C [pF] f(2) 33 22 650kHz 10 22 2.0MHz238 2486AA–AVR–02/2013 ATmega8(L) Two-wire Serial Interface Characteristics Table 101 describes the requirements for devices connected to the Two-wire Serial Bus. The ATmega8 Two-wire Serial Interface meets or exceeds these requirements under the noted conditions. Timing symbols refer to Figure 115 on page 239. Notes: 1. In ATmega8, this parameter is characterized and not 100% tested 2. Required only for fSCL > 100kHz 3. Cb = capacitance of one bus line in pF 4. fCK = CPU clock frequency Table 101. Two-wire Serial Bus Requirements Symbol Parameter Condition Min Max Units VIL Input Low-voltage -0.5 0.3VCC V VIH Input High-voltage 0.7VCC VCC + 0.5 Vhys(1) Hysteresis of Schmitt Trigger Inputs 0.05VCC(2) – VOL(1) Output Low-voltage 3mA sink Current 0 0.4 tr (1) Rise Time for both SDA and SCL 20 + 0.1Cb (3)(2) 300 tof ns (1) Output Fall Time from VIHmin to VILmax 10pF < Cb < 400pF(3) 20 + 0.1Cb (3)(2) 250 tSP(1) Spikes Suppressed by Input Filter 0 50(2) Ii Input Current each I/O Pin 0.1VCC < Vi < 0.9VCC -10 10 µA Ci (1) Capacitance for each I/O Pin – 10 pF fSCL SCL Clock Frequency fCK(4) > max(16fSCL, 250kHz)(5) 0 400 kHz Rp Value of Pull-up resistor fSCL  100kHz fSCL > 100kHz tHD;STA Hold Time (repeated) START Condition fSCL  100kHz 4.0 – µs fSCL > 100kHz 0.6 – tLOW Low Period of the SCL Clock fSCL  100kHz(6) 4.7 – fSCL > 100kHz(7) 1.3 – tHIGH High period of the SCL clock fSCL  100kHz 4.0 – fSCL > 100kHz 0.6 – tSU;STA Set-up time for a repeated START condition fSCL  100kHz 4.7 – fSCL > 100kHz 0.6 – tHD;DAT Data hold time fSCL  100kHz 0 3.45 fSCL > 100kHz 0 0.9 tSU;DAT Data setup time fSCL  100kHz 250 – ns fSCL > 100kHz 100 – tSU;STO Setup time for STOP condition fSCL  100kHz 4.0 – µs fSCL > 100kHz 0.6 – tBUF Bus free time between a STOP and START condition fSCL  100kHz 4.7 – fSCL > 100kHz 1.3 – VCC – 0.4V 3mA ---------------------------- 1000ns Cb -------------------  VCC – 0.4V 3mA ---------------------------- 300ns Cb ----------------239 2486AA–AVR–02/2013 ATmega8(L) 5. This requirement applies to all ATmega8 Two-wire Serial Interface operation. Other devices connected to the Two-wire Serial Bus need only obey the general fSCL requirement 6. The actual low period generated by the ATmega8 Two-wire Serial Interface is (1/fSCL - 2/fCK), thus fCK must be greater than 6MHz for the low time requirement to be strictly met at fSCL = 100kHz 7. The actual low period generated by the ATmega8 Two-wire Serial Interface is (1/fSCL - 2/fCK), thus the low time requirement will not be strictly met for fSCL > 308kHz when fCK = 8MHz. Still, ATmega8 devices connected to the bus may communicate at full speed (400kHz) with other ATmega8 devices, as well as any other device with a proper tLOW acceptance margin Figure 115. Two-wire Serial Bus Timing SPI Timing Characteristics See Figure 116 on page 240 and Figure 117 on page 240 for details. Note: 1. In SPI Programming mode the minimum SCK high/low period is: - 2tCLCL for fCK < 12MHz - 3tCLCL for fCK > 12MHz t SU;STA t LOW t HIGH t LOW t of t HD;STA t HD;DAT t SU;DAT t SU;STO t BUF SCL SDA t r Table 102. SPI Timing Parameters Description Mode Min Typ Max 1 SCK period Master See Table 50 on page 126 ns 2 SCK high/low Master 50% duty cycle 3 Rise/Fall time Master 3.6 4 Setup Master 10 5 Hold Master 10 6 Out to SCK Master 0.5 • tSCK 7 SCK to out Master 10 8 SCK to out high Master 10 9 SS low to out Slave 15 10 SCK period Slave 4 • tck 11 SCK high/low(1) Slave 2 • tck 12 Rise/Fall time Slave 1600 13 Setup Slave 10 14 Hold Slave 10 15 SCK to out Slave 15 16 SCK to SS high Slave 20 17 SS high to tri-state Slave 10 18 SS low to SCK Salve 2 • tck240 2486AA–AVR–02/2013 ATmega8(L) Figure 116. SPI interface timing requirements (Master Mode) Figure 117. SPI interface timing requirements (Slave Mode) MOSI (Data Output) SCK (CPOL = 1) MISO (Data Input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 6 1 2 2 4 5 3 7 8 MISO (Data Output) SCK (CPOL = 1) MOSI (Data Input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 10 11 11 13 14 12 15 17 9 X 16 18241 2486AA–AVR–02/2013 ATmega8(L) ADC Characteristics Notes: 1. Values are guidelines only 2. Minimum for AVCC is 2.7V 3. Maximum for AVCC is 5.5V 4. Maximum conversion time is 1/50kHz × 25 = 0.5ms Table 103. ADC Characteristics Symbol Parameter Condition Min(1) Typ(1) Max(1) Units Resolution Single Ended Conversion 10 Bits Absolute accuracy (including INL, DNL, Quantization Error, Gain, and Offset Error) Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 1.75 LSB Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 1MHz 3 Integral Non-linearity (INL) Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 0.75 Differential Non-linearity (DNL) Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 0.5 Gain Error Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 1 Offset Error Single Ended Conversion VREF = 4V, VCC = 4V ADC clock = 200kHz 1 Conversion Time(4) Free Running Conversion 13 260 µs Clock Frequency 50 1000 kHz AVCC Analog Supply Voltage VCC - 0.3(2) VCC + 0.3(3) V VREF Reference Voltage 2.0 AVCC VIN Input voltage GND VREF Input bandwidth 38.5 kHz VINT Internal Voltage Reference 2.3 2.56 2.9 V RREF Reference Input Resistance 32 k RAIN Analog Input Resistance 55 100 M242 2486AA–AVR–02/2013 ATmega8(L) Electrical Characteristics – TA = -40°C to 105°C Note: Typical values contained in this data sheet are based on simulations and characterization of other AVR microcontrollers manufactured on the same process technology. Min and Max values will be available after the device is characterized. Absolute Maximum Ratings* Operating Temperature.................................. -55C to +125C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage Temperature ..................................... -65°C to +150°C Voltage on any Pin except RESET with respect to Ground ................................-0.5V to VCC+0.5V Voltage on RESET with respect to Ground......-0.5V to +13.0V Maximum Operating Voltage ............................................ 6.0V DC Current per I/O Pin ............................................... 40.0 mA DC Current VCC and GND Pins................................ 200.0 mA DC Characteristics TA = -40C to 105C, VCC = 2.7V to 5.5V (unless otherwise noted) Symbol Parameter Condition Min Typ Max Units VIL Input Low Voltage Except XTAL1 pin -0.5 0.2 VCC(1) V VIL1 Input Low Voltage XTAL1 pin, External Clock Selected -0.5 0.1 VCC(1) V VIH Input High Voltage Except XTAL1 and RESET pins 0.6 VCC(2) VCC + 0.5 V VIH1 Input High Voltage XTAL1 pin, External Clock Selected 0.8 VCC(2) VCC + 0.5 V VIH2 Input High Voltage RESET pin 0.9 VCC(2) VCC + 0.5 V VOL Output Low Voltage(3) (Ports A,B,C,D) I OL = 20 mA, VCC = 5V IOL = 10 mA, VCC = 3V 0.8 0.6 V V VOH Output High Voltage(4) (Ports A,B,C,D) IOH = -20 mA, VCC = 5V IOH = -10 mA, VCC = 3V 4.0 2.2 V V IIL Input Leakage Current I/O Pin Vcc = 5.5V, pin low (absolute value) 3 µA IIH Input Leakage Current I/O Pin Vcc = 5.5V, pin high (absolute value) 3 µA RRST Reset Pull-up Resistor 30 80 k Rpu I/O Pin Pull-up Resistor 20 50 k243 2486AA–AVR–02/2013 ATmega8(L) Notes: 1. “Max” means the highest value where the pin is guaranteed to be read as low 2. “Min” means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP Package: 1] The sum of all IOL, for all ports, should not exceed 400 mA. 2] The sum of all IOL, for ports C0 - C5 should not exceed 200 mA. 3] The sum of all IOL, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 100 mA. TQFP and MLF Package: 1] The sum of all IOL, for all ports, should not exceed 400 mA. 2] The sum of all IOL, for ports C0 - C5, should not exceed 200 mA. 3] The sum of all IOL, for ports C6, D0 - D4, should not exceed 300 mA. 4] The sum of all IOL, for ports B0 - B7, D5 - D7, should not exceed 300 mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20mA at Vcc = 5V, 10mA at Vcc = 3V) under steady state conditions (non-transient), the following must be observed: PDIP Package: 1] The sum of all IOH, for all ports, should not exceed 400 mA. 2] The sum of all IOH, for port C0 - C5, should not exceed 100 mA. 3] The sum of all IOH, for ports B0 - B7, C6, D0 - D7 and XTAL2, should not exceed 100 mA. TQFP and MLF Package: 1] The sum of all IOH, for all ports, should not exceed 400 mA. 2] The sum of all IOH, for ports C0 - C5, should not exceed 200 mA. 3] The sum of all IOH, for ports C6, D0 - D4, should not exceed 300 mA. 4] The sum of all IOH, for ports B0 - B7, D5 - D7, should not exceed 300 mA. If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 5. Minimum VCC for Power-down is 2.5V. I CC Power Supply Current Active 4 MHz, VCC = 3V (ATmega8L) 6 mA Active 8 MHz, VCC = 5V (ATmega8) 15 mA Idle 4 MHz, VCC = 3V (ATmega8L) 3 mA Idle 8 MHz, VCC = 5V (ATmega8) 8 mA Power-down mode(5) WDT enabled, VCC = 3V 35 µA WDT disabled, VCC = 3V 6 µA VACIO Analog Comparator Input Offset Voltage VCC = 5V Vin = VCC/2 20 mV IACLK Analog Comparator Input Leakage Current VCC = 5V Vin = VCC/2 -50 50 nA tACPD Analog Comparator Propagation Delay VCC = 2.7V VCC = 5.0V 750 500 ns DC Characteristics TA = -40C to 105C, VCC = 2.7V to 5.5V (unless otherwise noted) (Continued) Symbol Parameter Condition Min Typ Max Units244 2486AA–AVR–02/2013 ATmega8(L) ATmega8 Typical Characteristics – TA = -40°C to 85°C The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A sine wave generator with Rail-to-Rail output is used as clock source. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as: CL × VCC × f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. Active Supply Current Figure 118. Active Supply Current vs. Frequency (0.1MHz - 1.0MHz) 0 0.5 1 1.5 2 2.5 3 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) 5.5V 5.0V 4.5V 3.3V 3.0V 2.7V 4.0V245 2486AA–AVR–02/2013 ATmega8(L) Figure 119. Active Supply Current vs. Frequency (1MHz - 20MHz) Figure 120. Active Supply Current vs. VCC (Internal RC Oscillator, 8MHz) 0 5 10 15 20 25 30 0246 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5V 5.0V 4.5V 3.3V 2.7V 3.0V 0 2 4 6 8 10 12 14 16 18 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C246 2486AA–AVR–02/2013 ATmega8(L) Figure 121. Active Supply Current vs. VCC (Internal RC Oscillator, 4MHz) Figure 122. Active Supply Current vs. VCC (Internal RC Oscillator, 2MHz) 0 2 4 6 8 10 12 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 0 1 2 3 4 5 6 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C247 2486AA–AVR–02/2013 ATmega8(L) Figure 123. Active Supply Current vs. VCC (Internal RC Oscillator, 1MHz) Figure 124. Active Supply Current vs. VCC (32kHz External Oscillator) 0 0.5 1 1.5 2 2.5 3 3.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 25°C 85°C -40°C 0 20 40 60 80 100 120 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 25°C248 2486AA–AVR–02/2013 ATmega8(L) Idle Supply Current Figure 125. Idle Supply Current vs. Frequency (0.1MHz - 1.0MHz) Figure 126. Idle Supply Current vs. Frequency (1MHz - 20MHz) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) 5.5V 4.5V 4.0V 3.3V 3.0V 2.7V 5.0V 0 2 4 6 8 10 12 14 0246 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5V 4.5V 4.0V 3.3V 3.0V 2.7V 5.0V249 2486AA–AVR–02/2013 ATmega8(L) Figure 127. Idle Supply Current vs. VCC (Internal RC Oscillator, 8MHz) Figure 128. Idle Supply Current vs. VCC (Internal RC Oscillator, 4MHz) 0 1 2 3 4 5 6 7 8 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 3.5 4 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C250 2486AA–AVR–02/2013 ATmega8(L) Figure 129. Idle Supply Current vs. VCC (Internal RC Oscillator, 2MHz) Figure 130. Idle Supply Current vs. VCC (Internal RC Oscillator, 1MHz) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C251 2486AA–AVR–02/2013 ATmega8(L) Figure 131. Idle Supply Current vs. VCC (32kHz External Oscillator) Power-down Supply Current Figure 132. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) 0 5 10 15 20 25 30 35 40 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 25°C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C252 2486AA–AVR–02/2013 ATmega8(L) Figure 133. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) Power-save Supply Current Figure 134. Power-save Supply Current vs. VCC (Watchdog Timer Disabled) 0 10 20 30 40 50 60 70 80 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C 0 5 10 15 20 25 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 25°C253 2486AA–AVR–02/2013 ATmega8(L) Standby Supply Current Figure 135. Standby Supply Current vs. VCC (455kHz Resonator, Watchdog Timer Disabled) Figure 136. Standby Supply Current vs. VCC (1MHz Resonator, Watchdog Timer Disabled) 0 10 20 30 40 50 60 70 80 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 0 10 20 30 40 50 60 70 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)254 2486AA–AVR–02/2013 ATmega8(L) Figure 137. Standby Supply Current vs. VCC (2MHz Resonator, Watchdog Timer Disabled) Figure 138. Standby Supply Current vs. VCC (2MHz Xtal, Watchdog Timer Disabled) 0 10 20 30 40 50 60 70 80 90 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 0 10 20 30 40 50 60 70 80 90 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)255 2486AA–AVR–02/2013 ATmega8(L) Figure 139. Standby Supply Current vs. VCC (4MHz Resonator, Watchdog Timer Disabled) Figure 140. Standby Supply Current vs. VCC (4MHz Xtal, Watchdog Timer Disabled) 0 20 40 60 80 100 120 140 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 0 20 40 60 80 100 120 140 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)256 2486AA–AVR–02/2013 ATmega8(L) Figure 141. Standby Supply Current vs. VCC (6MHz Resonator, Watchdog Timer Disabled) Figure 142. Standby Supply Current vs. VCC (6MHz Xtal, Watchdog Timer Disabled) 0 20 40 60 80 100 120 140 160 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 0 20 40 60 80 100 120 140 160 180 200 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)257 2486AA–AVR–02/2013 ATmega8(L) Pin Pull-up Figure 143. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 5V) Figure 144. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 2.7V) 0 20 40 60 80 100 120 140 160 012 3 4 56 VOP (V) IIO (µA) 85°C 25°C -40°C 0 10 20 30 40 50 60 70 80 90 0 0.5 1 1.5 2 2.5 3 VOP (V) IIO (µA) 85°C 25°C -40°C258 2486AA–AVR–02/2013 ATmega8(L) Figure 145. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) Figure 146. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) 0 20 40 60 80 100 012 VRESET (V) IRESET (µA) 85°C 25°C - 40°C 0 5 10 15 20 25 30 35 40 45 0 0.5 1 1.5 2 2.5 VRESET (V) IRESET (µA) 85°C 25°C -40°C259 2486AA–AVR–02/2013 ATmega8(L) Pin Driver Strength Figure 147. I/O Pin Source Current vs. Output Voltage (VCC = 5V) Figure 148. I/O Pin Source Current vs. Output Voltage (VCC = 2.7V) 0 10 20 30 40 50 60 70 80 VOH (V) IOH (mA) 85°C 25°C -40°C 0 5 10 15 20 25 30 0 0.5 1 1.5 2 2.5 3 VOH (V) IOH (mA) 85°C 25°C -40°C260 2486AA–AVR–02/2013 ATmega8(L) Figure 149. I/O Pin Sink Current vs. Output Voltage (VCC = 5V) Figure 150. I/O Pin Sink Current vs. Output Voltage (VCC = 2.7V) 0 10 20 30 40 50 60 70 80 90 0 0.5 1 1.5 2 2.5 VOL (V) IOL (mA) 85°C 25°C -40°C 0 5 10 15 20 25 30 35 0 0.5 1 1.5 2 2.5 VOL (V) IOL (mA) 85°C 25°C -40°C261 2486AA–AVR–02/2013 ATmega8(L) Figure 151. Reset Pin as I/O – Pin Source Current vs. Output Voltage (VCC = 5V) Figure 152. Reset Pin as I/O – Pin Source Current vs. Output Voltage (VCC = 2.7V) 0 0.5 1 1.5 2 2.5 3 3.5 4 2 2.5 3 3.5 4 4.5 VOH (V) Current (mA) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.5 1 1.5 2 2.5 VOH (V) Current (mA) 85°C 25°C -40°C262 2486AA–AVR–02/2013 ATmega8(L) Figure 153. Reset Pin as I/O – Pin Sink Current vs. Output Voltage (VCC = 5V) Figure 154. Reset Pin as I/O – Pin Sink Current vs. Output Voltage (VCC = 2.7V) 0 2 4 6 8 10 12 14 0 0.5 1 1.5 2 2.5 VOL (V) Current (mA) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 0.5 1 1.5 2 2.5 VOL (V) Current (mA) 85°C 25°C -40°C263 2486AA–AVR–02/2013 ATmega8(L) Pin Thresholds and Hysteresis Figure 155. I/O Pin Input Threshold Voltage vs. VCC (VIH, I/O Pin Read as “1”) Figure 156. I/O Pin Input Threshold Voltage vs. VCC (VIL, I/O Pin Read as “0”) 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C264 2486AA–AVR–02/2013 ATmega8(L) Figure 157. I/O Pin Input Hysteresis vs. VCC Figure 158. Reset Pin as I/O – Input Threshold Voltage vs. VCC (VIH, I/O Pin Read as “1”) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (V) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 3.5 4 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C265 2486AA–AVR–02/2013 ATmega8(L) Figure 159. Reset Pin as I/O – Input Threshold Voltage vs. VCC (VIL, I/O Pin Read as “0”) Figure 160. Reset Pin as I/O – Pin Hysteresis vs. VCC 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (V) 85°C 25°C -40°C266 2486AA–AVR–02/2013 ATmega8(L) Figure 161. Reset Input Threshold Voltage vs. VCC (VIH, Reset Pin Read as “1”) Figure 162. Reset Input Threshold Voltage vs. VCC (VIL, Reset Pin Read as “0”) 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C267 2486AA–AVR–02/2013 ATmega8(L) Figure 163. Reset Input Pin Hysteresis vs. VCC Bod Thresholds and Analog Comparator Offset Figure 164. BOD Thresholds vs. Temperature (BOD Level is 4.0V) 0 0.2 0.4 0.6 0.8 1 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input Hysteresis (V) 85°C 25°C -40°C 3.7 3.8 3.9 4 4.1 4.2 4.3 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) Threshold (V) Rising VCC Falling VCC268 2486AA–AVR–02/2013 ATmega8(L) Figure 165. BOD Thresholds vs. Temperature (BOD Level is 2.7V) Figure 166. Bandgap Voltage vs. VCC 2.4 2.5 2.6 2.7 2.8 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) Threshold (V) Rising VCC Falling VCC 1.29 1.295 1.3 1.305 1.31 1.315 2.5 3 3.5 4 4.5 5 5.5 Vcc (V) Bandgap Voltage (V) -40°C 25°C 85°C269 2486AA–AVR–02/2013 ATmega8(L) Figure 167. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 5V) Figure 168. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 2.7V) -0.006 -0.005 -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Common Mode Voltage (V) Comparator Offset Voltage (V) 85°C 25°C -40°C -0.005 -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003 0 0.5 1 1.5 2 2.5 3 Common Mode Voltage (V) Comparator Offset Voltage (V) 85°C 25°C -40°C270 2486AA–AVR–02/2013 ATmega8(L) Internal Oscillator Speed Figure 169. Watchdog Oscillator Frequency vs. VCC Figure 170. Calibrated 8MHz RC Oscillator Frequency vs. Temperature 1100 1120 1140 1160 1180 1200 1220 1240 1260 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (kHz) 85°C 25°C -40°C 6.5 6.7 6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3 8.5 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) FRC (MHz) 5.5V 2.7V 4.0V271 2486AA–AVR–02/2013 ATmega8(L) Figure 171. Calibrated 8MHz RC Oscillator Frequency vs. VCC Figure 172. Calibrated 8MHz RC Oscillator Frequency vs. Osccal Value 6.5 6.7 6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3 8.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C 4 6 8 10 12 14 16 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL VALUE FRC (MHz)272 2486AA–AVR–02/2013 ATmega8(L) Figure 173. Calibrated 4MHz RC Oscillator Frequency vs. Temperature Figure 174. Calibrated 4MHz RC Oscillator Frequency vs. VCC 3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) FRC (MHz) 5.5V 2.7V 4.0V 3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C273 2486AA–AVR–02/2013 ATmega8(L) Figure 175. Calibrated 4MHz RC Oscillator Frequency vs. Osccal Value Figure 176. Calibrated 2MHz RC Oscillator Frequency vs. Temperature 2 3 4 5 6 7 8 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL VALUE FRC (MHz) 1.8 1.85 1.9 1.95 2 2.05 2.1 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) FRC (MHz) 5.5V 2.7V 4.0V274 2486AA–AVR–02/2013 ATmega8(L) Figure 177. Calibrated 2MHz RC Oscillator Frequency vs. VCC Figure 178. Calibrated 2MHz RC Oscillator Frequency vs. Osccal Value 1.7 1.8 1.9 2 2.1 2.2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C 0.8 1.3 1.8 2.3 2.8 3.3 3.8 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL VALUE FRC (MHz)275 2486AA–AVR–02/2013 ATmega8(L) Figure 179. Calibrated 1MHz RC Oscillator Frequency vs. Temperature Figure 180. Calibrated 1MHz RC Oscillator Frequency vs. VCC 0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 -60 -40 -20 0 20 40 60 80 100 Temperature (°C) FRC (MHz) 5.5V 2.7V 4.0V 0.9 0.95 1 1.05 1.1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C276 2486AA–AVR–02/2013 ATmega8(L) Figure 181. Calibrated 1MHz RC Oscillator Frequency vs. Osccal Value Current Consumption of Peripheral Units Figure 182. Brown-out Detector Current vs. VCC 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL VALUE FRC (MHz) 0 5 10 15 20 25 30 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 25°C 85°C -40°C277 2486AA–AVR–02/2013 ATmega8(L) Figure 183. ADC Current vs. VCC (AREF = AVCC) Figure 184. AREF External Reference Current vs. VCC 0 50 100 150 200 250 300 350 400 450 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C 0 50 100 150 200 250 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C278 2486AA–AVR–02/2013 ATmega8(L) Figure 185. 32kHz TOSC Current vs. VCC (Watchdog Timer Disabled) Figure 186. Watchdog Timer Current vs. VCC 0 5 10 15 20 25 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 25°C 0 10 20 30 40 50 60 70 80 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C279 2486AA–AVR–02/2013 ATmega8(L) Figure 187. Analog Comparator Current vs. VCC Figure 188. Programming Current vs. VCC 0 10 20 30 40 50 60 70 80 90 100 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 25°C 85°C -40°C 0 1 2 3 4 5 6 7 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 25°C 85°C -40°C280 2486AA–AVR–02/2013 ATmega8(L) Current Consumption in Reset and Reset Pulsewidth Figure 189. Reset Supply Current vs. VCC (0.1MHz - 1.0MHz, Excluding Current Through The Reset Pull-up) Figure 190. Reset Supply Current vs. VCC (1MHz - 20MHz, Excluding Current Through The Reset Pull-up) 0 0.5 1 1.5 2 2.5 3 3.5 4 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) 5.5V 5.0V 4.5V 3.3V 3.0V 2.7V 4.0V 0 5 10 15 20 25 0246 8 10 12 14 16 18 20 Frequency (MHz) ICC (mA) 5.5V 5.0V 4.5V 3.3V 3.0V 2.7V281 2486AA–AVR–02/2013 ATmega8(L) Figure 191. Reset Pulse Width vs. VCC 0 200 400 600 800 1000 1200 1400 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Pulsewidth (ns) 85°C 25°C -40°C282 2486AA–AVR–02/2013 ATmega8(L) ATmega8 Typical Characteristics – TA = -40°C to 105°C The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A sine wave generator with Rail-to-Rail output is used as clock source. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as CL*VCC*f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. Active Supply Current Figure 0-1. Active Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) ACTIVE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 8 MHz 0 2 4 6 8 10 12 14 16 18 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C283 2486AA–AVR–02/2013 ATmega8(L) Figure 0-2. Active Supply Current vs. VCC (Internal RC Oscillator, 4 MHz) Figure 0-3. Active Supply Current vs. VCC (Internal RC Oscillator, 2 MHz) ACTIVE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 4 MHz 0 2 4 6 8 10 12 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C ACTIVE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 2 MHz 0 1 2 3 4 5 6 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C284 2486AA–AVR–02/2013 ATmega8(L) Figure 0-4. Active Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) Idle Supply Current Figure 0-5. Idle Supply Current vs. VCC (Internal RC Oscillator, 8 MHz) ACTIVE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 1 MHz 0 0.5 1 1.5 2 2.5 3 3.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C IDLE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 8 MHz 0 1 2 3 4 5 6 7 8 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C285 2486AA–AVR–02/2013 ATmega8(L) Figure 0-6. Idle Supply Current vs. VCC (Internal RC Oscillator, 4 MHz) Figure 0-7. Idle Supply Current vs. VCC (Internal RC Oscillator, 2 MHz) IDLE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 4 MHz 0 0.5 1 1.5 2 2.5 3 3.5 4 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C IDLE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 2 MHz 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C286 2486AA–AVR–02/2013 ATmega8(L) Figure 0-8. Idle Supply Current vs. VCC (Internal RC Oscillator, 1 MHz) Power-down Supply Current Figure 0-9. Power-down Supply Current vs. VCC (Watchdog Timer Disabled) IDLE SUPPLY CURRENT vs. VCC INTERNAL RC OSCILLATOR, 1 MHz 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 105°C POWER-DOWN SUPPLY CURRENT vs. VCC WATCHDOG TIMER DISABLED 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 105°C 25°C -40°C 85°C287 2486AA–AVR–02/2013 ATmega8(L) Figure 0-10. Power-down Supply Current vs. VCC (Watchdog Timer Enabled) Pin Pull-up Figure 0-11. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 5V) POWER-DOWN SUPPLY CURRENT vs. VCC WATCHDOG TIMER ENABLED 0 10 20 30 40 50 60 70 80 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C -40°C 105°C I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE Vcc = 5V 0 20 40 60 80 100 120 140 160 0123 VOP (V) IOP (uA) 85°C 25°C -40°C 105°C288 2486AA–AVR–02/2013 ATmega8(L) Figure 0-12. I/O Pin Pull-up Resistor Current vs. Input Voltage (VCC = 2.7V) Figure 0-13. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 5V) I/O PIN PULL-UP RESISTOR CURRENT vs. INPUT VOLTAGE Vcc = 2.7V 0 10 20 30 40 50 60 70 80 90 0 0.5 1 1.5 2 2.5 3 VOP (V) IOP (uA) 85°C 25°C -40°C 105°C RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE Vcc = 5V 0 20 40 60 80 100 012 VRESET (V) IRESET (uA) 85°C 25°C 105°C -40°C289 2486AA–AVR–02/2013 ATmega8(L) Figure 0-14. Reset Pull-up Resistor Current vs. Reset Pin Voltage (VCC = 2.7V) Pin Driver Strength Figure 0-15. I/O Pin Source Current vs. Output Voltage (VCC = 5V) RESET PULL-UP RESISTOR CURRENT vs. RESET PIN VOLTAGE Vcc = 2.7V 0 5 10 15 20 25 30 35 40 45 0 0.5 1 1.5 2 2.5 VRESET (V) IRESET (uA) 85°C 25°C -40°C 105°C I/O PIN SOURCE CURRENT vs. OUTPUT VOLTAGE Vcc = 5V 0 10 20 30 40 50 60 70 80 01234 VOH (V) IOH (mA) 85°C 25°C -40°C 105°C290 2486AA–AVR–02/2013 ATmega8(L) Figure 0-16. I/O Pin Source Current vs. Output Voltage (VCC = 2.7V) Figure 0-17. I/O Pin Sink Current vs. Output Voltage (VCC = 5V) I/O PIN SOURCE CURRENT vs. OUTPUT VOLTAGE Vcc = 2.7V 0 5 10 15 20 25 30 0 0.5 1 1.5 2 2.5 3 VOH (V) IOH (mA) 85°C 25°C -40°C 105°C I/O PIN SINK CURRENT vs. OUTPUT VOLTAGE Vcc = 5V 0 10 20 30 40 50 60 70 80 90 0 0.5 1 1.5 2 2.5 VOL (V) IOL (mA) 85°C 25°C -40°C 105°C291 2486AA–AVR–02/2013 ATmega8(L) Figure 0-18. I/O Pin Sink Current vs. Output Voltage (VCC = 2.7V) Figure 0-19. Reset Pin as I/O – Pin Source Current vs. Output Voltage (VCC = 5V) I/O PIN SINK CURRENT vs. OUTPUT VOLTAGE Vcc = 2.7V 0 5 10 15 20 25 30 35 0 0.5 1 1.5 2 2.5 VOL (V) IOL (mA) 85°C 25°C -40°C 105°C RESET PIN AS I/O - SOURCE CURRENT vs. OUTPUT VOLTAGE Vcc = 5V 0 0.5 1 1.5 2 2.5 3 3.5 4 2 2.5 3 3.5 4 4.5 VOH (V) Current (mA) 85°C 25°C -40°C 105°C292 2486AA–AVR–02/2013 ATmega8(L) Figure 0-20. Reset Pin as I/O – Pin Source Current vs. Output Voltage (VCC = 2.7V) Figure 0-21. Reset Pin as I/O – Pin Sink Current vs. Output Voltage (VCC = 5V) RESET PIN AS I/O - SOURCE CURRENT vs. OUTPUT VOLTAGE Vcc = 2.7V 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.5 1 1.5 2 2.5 VOH (V) Current (mA) 85°C 25°C -40°C 105 °C RESET PIN AS I/O - SINK CURRENT vs. OUTPUT VOLTAGE Vcc = 5V 0 2 4 6 8 10 12 14 0 0.5 1 1.5 2 2.5 VOL (V) Current (mA) 85°C 25°C -40°C 105°C293 2486AA–AVR–02/2013 ATmega8(L) Figure 0-22. Reset Pin as I/O – Pin Sink Current vs. Output Voltage (VCC = 2.7V) Pin Thresholds and Hysteresis Figure 0-23. I/O Pin Input Threshold Voltage vs. VCC (VIH, I/O Pin Read as “1”) RESET PIN AS I/O - SINK CURRENT vs. OUTPUT VOLTAGE Vcc = 2.7V 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 0.5 1 1.5 2 2.5 VOL (V) Current (mA) 85°C 25°C -40°C 105°C I/O PIN INPUT THRESHOLD VOLTAGE vs. VCC VIH, IO PIN READ AS '1' 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 105°C -40°C 25°C294 2486AA–AVR–02/2013 ATmega8(L) Figure 0-24. I/O Pin Input Threshold Voltage vs. VCC (VIL, I/O Pin Read as “0”) Figure 0-25. I/O Pin Input Hysteresis vs. VCC I/O PIN INPUT THRESHOLD VOLTAGE vs. VCC VIL, IO PIN READ AS '0' 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C I/O PIN INPUT HYSTERESIS vs. VCC 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C295 2486AA–AVR–02/2013 ATmega8(L) Figure 0-26. Reset Pin as I/O – Input Threshold Voltage vs. VCC (VIH,I/O Pin Read as “1”) Figure 0-27. Reset Pin as I/O – Input Threshold Voltage vs. VCC (VIL, I/O Pin Read as “0”) RESET PIN AS I/O - INPUT THRESHOLD VOLTAGE vs. VCC VIH, RESET PIN READ AS '1' 0 0.5 1 1.5 2 2.5 3 3.5 4 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C RESET PIN AS I/O - INPUT THRESHOLD VOLTAGE vs. VCC VIL, RESET PIN READ AS '0' 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C296 2486AA–AVR–02/2013 ATmega8(L) Figure 0-28. Reset Pin as I/O – Pin Hysteresis vs. VCC Figure 0-29. Reset Input Threshold Voltage vs. VCC (VIH, Reset Pin Read as “1”) RESET PIN AS I/O - PIN HYSTERESIS vs. VCC 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C RESET INPUT THRESHOLD VOLTAGE vs. VCC VIH, RESET PIN READ AS '1' 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C297 2486AA–AVR–02/2013 ATmega8(L) Figure 0-30. Reset Input Threshold Voltage vs. VCC (VIL, Reset Pin Read as “0”) Figure 0-31. Reset Input Pin Hysteresis vs. VCC RESET INPUT THRESHOLD VOLTAGE vs. VCC VIL, RESET PIN READ AS '0' 0 0.5 1 1.5 2 2.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C RESET INPUT PIN HYSTERESIS vs. VCC 0 0.2 0.4 0.6 0.8 1 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 105°C298 2486AA–AVR–02/2013 ATmega8(L) Bod Thresholds and Analog Comparator Offset Figure 0-32. BOD Thresholds vs. Temperature (BOD Level is 4.0V) Figure 0-33. BOD Thresholds vs. Temperature (BOD Level is 2.7V) BOD THRESHOLDS vs. TEMPERATURE BODLEVEL IS 4.0V 3.8 3.9 4 4.1 4.2 4.3 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Temperature (˚C) Threshold (V) Rising VCC Falling VCC BOD THRESHOLDS vs. TEMPERATURE BODLEVEL IS 2.7V 2.4 2.5 2.6 2.7 2.8 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Temperature (˚C) Threshold (V) Rising VCC Falling VCC299 2486AA–AVR–02/2013 ATmega8(L) Figure 0-34. Bandgap Voltage vs. VCC Figure 0-35. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 5V) BANDGAP VOLTAGE vs. VCC 1.29 1.295 1.3 1.305 1.31 1.315 2.5 3 3.5 4 4.5 5 5.5 Vcc (V) Bandgap Voltage (V) 85°C 25°C -40°C 105°C ANALOG COMPARATOR OFFSET VOLTAGE vs. COMMON MODE VOLTAGE VCC = 5V -0.006 -0.005 -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Common Mode Voltage (V) Comparator Offset Voltage (V) 85°C 25°C -40°C 105°C300 2486AA–AVR–02/2013 ATmega8(L) Figure 0-36. Analog Comparator Offset Voltage vs. Common Mode Voltage (VCC = 2.7V) Internal Oscillator Speed Figure 0-37. Watchdog Oscillator Frequency vs. VCC ANALOG COMPARATOR OFFSET VOLTAGE vs. COMMON MODE VOLTAGE VCC = 2.7V -0.005 -0.004 -0.003 -0.002 -0.001 0 0.001 0.002 0.003 0 0.5 1 1.5 2 2.5 3 Common Mode Voltage (V) Comparator Offset Voltage (V) 85°C 25°C -40°C 105°C WATCHDOG OSCILLATOR FREQUENCY vs. VCC 1080 1100 1120 1140 1160 1180 1200 1220 1240 1260 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (kHz) 85°C 25°C -40°C 105°C301 2486AA–AVR–02/2013 ATmega8(L) Figure 0-38. Calibrated 8 MHz RC Oscillator Frequency vs. Temperature Figure 0-39. Calibrated 8 MHz RC Oscillator Frequency vs. VCC CALIBRATED 8MHz RC OSCILLATOR FREQUENCY vs. TEMPERATURE 6.5 6.7 6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3 8.5 -60 -40 -20 0 20 40 60 80 100 120 Temperature (˚C) FRC (MHz) 5.5V 2.7V 4.0V CALIBRATED 8MHz RC OSCILLATOR FREQUENCY vs. VCC 6.5 6.7 6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3 8.5 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C 105°C302 2486AA–AVR–02/2013 ATmega8(L) Figure 0-40. Calibrated 4 MHz RC Oscillator Frequency vs. Temperature Figure 0-41. Calibrated 4 MHz RC Oscillator Frequency vs. VCC CALIBRATED 4MHz RC OSCILLATOR FREQUENCY vs. TEMPERATURE 3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 -60 -40 -20 0 20 40 60 80 100 120 Temperature (˚C) FRC (MHz) 5.5V 2.7V 4.0V CALIBRATED 4MHz RC OSCILLATOR FREQUENCY vs. VCC 3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C 105°C303 2486AA–AVR–02/2013 ATmega8(L) Figure 0-42. Calibrated 2 MHz RC Oscillator Frequency vs. Temperature Figure 0-43. Calibrated 2 MHz RC Oscillator Frequency vs. VCC CALIBRATED 2MHz RC OSCILLATOR FREQUENCY vs. TEMPERATURE 1.75 1.8 1.85 1.9 1.95 2 2.05 2.1 -60 -40 -20 0 20 40 60 80 100 120 Temperature (˚C) FRC (MHz) 5.5V 2.7V 4.0V CALIBRATED 2MHz RC OSCILLATOR FREQUENCY vs. VCC 1.7 1.8 1.9 2 2.1 2.2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C 105°C304 2486AA–AVR–02/2013 ATmega8(L) Figure 0-44. Calibrated 1 MHz RC Oscillator Frequency vs. Temperature Figure 0-45. Calibrated 1 MHz RC Oscillator Frequency vs. VCC CALIBRATED 1MHz RC OSCILLATOR FREQUENCY vs. TEMPERATURE 0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 -60 -40 -20 0 20 40 60 80 100 120 Temperature (˚C) FRC (MHz) 5.5V 2.7V 4.0V CALIBRATED 1MHz RC OSCILLATOR FREQUENCY vs. VCC 0.9 0.95 1 1.05 1.1 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz) 85°C 25°C -40°C 105°C305 2486AA–AVR–02/2013 ATmega8(L) Current Consumption of Peripheral Units Figure 0-46. Brown-out Detector Current vs. VCC Figure 0-47. ADC Current vs. VCC (AREF = AVCC) BROWNOUT DETECTOR CURRENT vs. VCC 0 5 10 15 20 25 30 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25°C 85°C -40°C 105°C ADC CURRENT vs. VCC AREF = AVCC 0 50 100 150 200 250 300 350 400 450 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C -40°C 105°C306 2486AA–AVR–02/2013 ATmega8(L) Figure 0-48. AREF External Reference Current vs. VCC Figure 0-49. Watchdog Timer Current vs. VCC AREF EXTERNAL REFERENCE CURRENT vs. VCC 0 50 100 150 200 250 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 85°C 25°C -40°C 105°C WATCHDOG TIMER CURRENT vs. VCC 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 105°C 25°C -40°C 85°C307 2486AA–AVR–02/2013 ATmega8(L) Figure 0-50. Analog Comparator Current vs. VCC Figure 0-51. Programming Current vs. VCC ANALOG COMPARATOR CURRENT vs. VCC 0 20 40 60 80 100 120 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25°C 105°C -40°C 85°C PROGRAMMING CURRENT vs. VCC 0 1 2 3 4 5 6 7 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (uA) 25°C 85°C -40°C 105°C308 2486AA–AVR–02/2013 ATmega8(L) Current Consumption in Reset and Reset Pulsewidth Figure 0-52. Reset Pulse Width vs. VCC RESET PULSE WIDTH vs. VCC 0 200 400 600 800 1000 1200 1400 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Pulsewidth (ns) 85°C 25°C -40°C 105°C309 2486AA–AVR–02/2013 ATmega8(L) Register Summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page 0x3F (0x5F) SREG I T H S V N Z C 11 0x3E (0x5E) SPH – – – – – SP10 SP9 SP8 13 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 13 0x3C (0x5C) Reserved 0x3B (0x5B) GICR INT1 INT0 – – – – IVSEL IVCE 49, 67 0x3A (0x5A) GIFR INTF1 INTF0 – – – – – – 67 0x39 (0x59) TIMSK OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 72, 100, 119 0x38 (0x58) TIFR OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 72, 101, 119 0x37 (0x57) SPMCR SPMIE RWWSB – RWWSRE BLBSET PGWRT PGERS SPMEN 206 0x36 (0x56) TWCR TWINT TWEA TWSTA TWSTO TWWC TWEN – TWIE 165 0x35 (0x55) MCUCR SE SM2 SM1 SM0 ISC11 ISC10 ISC01 ISC00 33, 66 0x34 (0x54) MCUCSR – – – – WDRF BORF EXTRF PORF 41 0x33 (0x53) TCCR0 – – – – – CS02 CS01 CS00 71 0x32 (0x52) TCNT0 Timer/Counter0 (8 Bits) 72 0x31 (0x51) OSCCAL Oscillator Calibration Register 31 0x30 (0x50) SFIOR – – – – ACME PUD PSR2 PSR10 58, 74, 120, 186 0x2F (0x4F) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 FOC1A FOC1B WGM11 WGM10 96 0x2E (0x4E) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 98 0x2D (0x4D) TCNT1H Timer/Counter1 – Counter Register High byte 99 0x2C (0x4C) TCNT1L Timer/Counter1 – Counter Register Low byte 99 0x2B (0x4B) OCR1AH Timer/Counter1 – Output Compare Register A High byte 99 0x2A (0x4A) OCR1AL Timer/Counter1 – Output Compare Register A Low byte 99 0x29 (0x49) OCR1BH Timer/Counter1 – Output Compare Register B High byte 99 0x28 (0x48) OCR1BL Timer/Counter1 – Output Compare Register B Low byte 99 0x27 (0x47) ICR1H Timer/Counter1 – Input Capture Register High byte 100 0x26 (0x46) ICR1L Timer/Counter1 – Input Capture Register Low byte 100 0x25 (0x45) TCCR2 FOC2 WGM20 COM21 COM20 WGM21 CS22 CS21 CS20 114 0x24 (0x44) TCNT2 Timer/Counter2 (8 Bits) 116 0x23 (0x43) OCR2 Timer/Counter2 Output Compare Register 116 0x22 (0x42) ASSR – – – – AS2 TCN2UB OCR2UB TCR2UB 117 0x21 (0x41) WDTCR – – – WDCE WDE WDP2 WDP1 WDP0 43 0x20(1) (0x40)(1) UBRRH URSEL – – – UBRR[11:8] 152 UCSRC URSEL UMSEL UPM1 UPM0 USBS UCSZ1 UCSZ0 UCPOL 150 0x1F (0x3F) EEARH – – – – – – – EEAR8 20 0x1E (0x3E) EEARL EEAR7 EEAR6 EEAR5 EEAR4 EEAR3 EEAR2 EEAR1 EEAR0 20 0x1D (0x3D) EEDR EEPROM Data Register 20 0x1C (0x3C) EECR – – – – EERIE EEMWE EEWE EERE 20 0x1B (0x3B) Reserved 0x1A (0x3A) Reserved 0x19 (0x39) Reserved 0x18 (0x38) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 65 0x17 (0x37) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 65 0x16 (0x36) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 65 0x15 (0x35) PORTC – PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 65 0x14 (0x34) DDRC – DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 65 0x13 (0x33) PINC – PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 65 0x12 (0x32) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 65 0x11 (0x31) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 65 0x10 (0x30) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 65 0x0F (0x2F) SPDR SPI Data Register 127 0x0E (0x2E) SPSR SPIF WCOL – – – – – SPI2X 126 0x0D (0x2D) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 125 0x0C (0x2C) UDR USART I/O Data Register 148 0x0B (0x2B) UCSRA RXC TXC UDRE FE DOR PE U2X MPCM 148 0x0A (0x2A) UCSRB RXCIE TXCIE UDRIE RXEN TXEN UCSZ2 RXB8 TXB8 149 0x09 (0x29) UBRRL USART Baud Rate Register Low byte 152 0x08 (0x28) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 186 0x07 (0x27) ADMUX REFS1 REFS0 ADLAR – MUX3 MUX2 MUX1 MUX0 199 0x06 (0x26) ADCSRA ADEN ADSC ADFR ADIF ADIE ADPS2 ADPS1 ADPS0 200 0x05 (0x25) ADCH ADC Data Register High byte 201 0x04 (0x24) ADCL ADC Data Register Low byte 201 0x03 (0x23) TWDR Two-wire Serial Interface Data Register 167 0x02 (0x22) TWAR TWA6 TWA5 TWA4 TWA3 TWA2 TWA1 TWA0 TWGCE 167310 2486AA–AVR–02/2013 ATmega8(L) Notes: 1. Refer to the USART description (“USART” on page 129) for details on how to access UBRRH and UCSRC (“Accessing UBRRH/UCSRC Registers” on page 146) 2. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written 3. Some of the Status Flags are cleared by writing a logical one to them. Note that the CBI and SBI instructions will operate on all bits in the I/O Register, writing a one back into any flag read as set, thus clearing the flag. The CBI and SBI instructions work with registers 0x00 to 0x1F only 0x01 (0x21) TWSR TWS7 TWS6 TWS5 TWS4 TWS3 – TWPS1 TWPS0 166 0x00 (0x20) TWBR Two-wire Serial Interface Bit Rate Register 165 Register Summary (Continued) Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page311 2486AA–AVR–02/2013 ATmega8(L) Instruction Set Summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd  Rd + Rr Z, C, N, V, H 1 ADC Rd, Rr Add with Carry two Registers Rd  Rd + Rr + C Z, C, N, V, H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl  Rdh:Rdl + K Z, C, N, V, S 2 SUB Rd, Rr Subtract two Registers Rd  Rd - Rr Z, C, N, V, H 1 SUBI Rd, K Subtract Constant from Register Rd  Rd - K Z, C, N, V, H 1 SBC Rd, Rr Subtract with Carry two Registers Rd  Rd - Rr - C Z, C, N, V, H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd  Rd - K - C Z, C, N ,V, H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl  Rdh:Rdl - K Z, C, N, V, S 2 AND Rd, Rr Logical AND Registers Rd Rd  Rr Z, N, V 1 ANDI Rd, K Logical AND Register and Constant Rd  Rd K Z, N, V 1 OR Rd, Rr Logical OR Registers Rd  Rd v Rr Z, N, V 1 ORI Rd, K Logical OR Register and Constant Rd Rd v K Z, N, V 1 EOR Rd, Rr Exclusive OR Registers Rd  Rd  Rr Z, N, V 1 COM Rd One’s Complement Rd  0xFF  Rd Z, C, N, V 1 NEG Rd Two’s Complement Rd  0x00  Rd Z, C, N, V, H 1 SBR Rd,K Set Bit(s) in Register Rd  Rd v K Z, N, V 1 CBR Rd,K Clear Bit(s) in Register Rd  Rd  (0xFF - K) Z, N, V 1 INC Rd Increment Rd  Rd + 1 Z, N, V 1 DEC Rd Decrement Rd  Rd  1 Z, N, V 1 TST Rd Test for Zero or Minus Rd  Rd  Rd Z, N, V 1 CLR Rd Clear Register Rd  Rd  Rd Z, N, V 1 SER Rd Set Register Rd  0xFF None 1 MUL Rd, Rr Multiply Unsigned R1:R0  Rd x Rr Z, C 2 MULS Rd, Rr Multiply Signed R1:R0  Rd x Rr Z, C 2 MULSU Rd, Rr Multiply Signed with Unsigned R1:R0  Rd x Rr Z, C 2 FMUL Rd, Rr Fractional Multiply Unsigned R1:R0  (Rd x Rr) << 1 Z, C 2 FMULS Rd, Rr Fractional Multiply Signed R1:R0  (Rd x Rr) << 1 Z, C 2 FMULSU Rd, Rr Fractional Multiply Signed with Unsigned R1:R0  (Rd x Rr) << 1 Z, C 2 BRANCH INSTRUCTIONS RJMP k Relative Jump PC PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC  Z None 2 RCALL k Relative Subroutine Call PC  PC + k + 1 None 3 ICALL Indirect Call to (Z) PC  Z None 3 RET Subroutine Return PC  STACK None 4 RETI Interrupt Return PC  STACK I 4 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC PC + 2 or 3 None 1 / 2 / 3 CP Rd,Rr Compare Rd  Rr Z, N, V, C, H 1 CPC Rd,Rr Compare with Carry Rd  Rr  C Z, N, V, C, H 1 CPI Rd,K Compare Register with Immediate Rd  K Z, N, V, C, H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC  PC + 2 or 3 None 1 / 2 / 3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC  PC + 2 or 3 None 1 / 2 / 3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC  PC + 2 or 3 None 1 / 2 / 3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC  PC + 2 or 3 None 1 / 2 / 3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PCPC+k + 1 None 1 / 2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PCPC+k + 1 None 1 / 2 BREQ k Branch if Equal if (Z = 1) then PC  PC + k + 1 None 1 / 2 BRNE k Branch if Not Equal if (Z = 0) then PC  PC + k + 1 None 1 / 2 BRCS k Branch if Carry Set if (C = 1) then PC  PC + k + 1 None 1 / 2 BRCC k Branch if Carry Cleared if (C = 0) then PC  PC + k + 1 None 1 / 2 BRSH k Branch if Same or Higher if (C = 0) then PC  PC + k + 1 None 1 / 2 BRLO k Branch if Lower if (C = 1) then PC  PC + k + 1 None 1 / 2 BRMI k Branch if Minus if (N = 1) then PC  PC + k + 1 None 1 / 2 BRPL k Branch if Plus if (N = 0) then PC  PC + k + 1 None 1 / 2 BRGE k Branch if Greater or Equal, Signed if (N  V= 0) then PC  PC + k + 1 None 1 / 2 BRLT k Branch if Less Than Zero, Signed if (N  V= 1) then PC  PC + k + 1 None 1 / 2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC  PC + k + 1 None 1 / 2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC  PC + k + 1 None 1 / 2 BRTS k Branch if T Flag Set if (T = 1) then PC  PC + k + 1 None 1 / 2 BRTC k Branch if T Flag Cleared if (T = 0) then PC  PC + k + 1 None 1 / 2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC  PC + k + 1 None 1 / 2 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC  PC + k + 1 None 1 / 2312 2486AA–AVR–02/2013 ATmega8(L) Mnemonics Operands Description Operation Flags #Clocks BRIE k Branch if Interrupt Enabled if ( I = 1) then PC  PC + k + 1 None 1 / 2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC  PC + k + 1 None 1 / 2 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd  Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd  Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd  K None 1 LD Rd, X Load Indirect Rd  (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd  (X), X  X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X  X - 1, Rd  (X) None 2 LD Rd, Y Load Indirect Rd  (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd  (Y), Y  Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y  Y - 1, Rd  (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd  (Y + q) None 2 LD Rd, Z Load Indirect Rd  (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd  (Z), Z  Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z  Z - 1, Rd  (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd  (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd  (k) None 2 ST X, Rr Store Indirect (X) Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) Rr, X  X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X  X - 1, (X)  Rr None 2 ST Y, Rr Store Indirect (Y)  Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y)  Rr, Y  Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y  Y - 1, (Y)  Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q)  Rr None 2 ST Z, Rr Store Indirect (Z)  Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z)  Rr, Z  Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z  Z - 1, (Z)  Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q)  Rr None 2 STS k, Rr Store Direct to SRAM (k)  Rr None 2 LPM Load Program Memory R0  (Z) None 3 LPM Rd, Z Load Program Memory Rd  (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd  (Z), Z  Z+1 None 3 SPM Store Program Memory (Z)  R1:R0 None - IN Rd, P In Port Rd  P None 1 OUT P, Rr Out Port P  Rr None 1 PUSH Rr Push Register on Stack STACK  Rr None 2 POP Rd Pop Register from Stack Rd  STACK None 2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b)  1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b)  0 None 2 LSL Rd Logical Shift Left Rd(n+1)  Rd(n), Rd(0)  0 Z, C, N, V 1 LSR Rd Logical Shift Right Rd(n)  Rd(n+1), Rd(7)  0 Z, C, N, V 1 ROL Rd Rotate Left Through Carry Rd(0)C,Rd(n+1) Rd(n),CRd(7) Z, C, N, V 1 ROR Rd Rotate Right Through Carry Rd(7)C,Rd(n) Rd(n+1),CRd(0) Z, C, N, V 1 ASR Rd Arithmetic Shift Right Rd(n)  Rd(n+1), n=0..6 Z, C, N, V 1 SWAP Rd Swap Nibbles Rd(3..0)Rd(7..4),Rd(7..4)Rd(3..0) None 1 BSET s Flag Set SREG(s)  1 SREG(s) 1 BCLR s Flag Clear SREG(s)  0 SREG(s) 1 BST Rr, b Bit Store from Register to T T  Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b)  T None 1 SEC Set Carry C  1 C1 CLC Clear Carry C  0 C 1 SEN Set Negative Flag N  1 N1 CLN Clear Negative Flag N  0 N 1 SEZ Set Zero Flag Z  1 Z1 CLZ Clear Zero Flag Z  0 Z 1 SEI Global Interrupt Enable I  1 I1 CLI Global Interrupt Disable I 0 I 1 SES Set Signed Test Flag S  1 S1 CLS Clear Signed Test Flag S  0 S 1 SEV Set Twos Complement Overflow. V  1 V1 CLV Clear Twos Complement Overflow V  0 V 1 SET Set T in SREG T  1 T1 Instruction Set Summary (Continued)313 2486AA–AVR–02/2013 ATmega8(L) Mnemonics Operands Description Operation Flags #Clocks CLT Clear T in SREG T  0 T 1 SEH Set Half Carry Flag in SREG H  1 H1 CLH Clear Half Carry Flag in SREG H  0 H 1 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/timer) None 1 Instruction Set Summary (Continued)314 2486AA–AVR–02/2013 ATmega8(L) Ordering Information Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities 2. Pb-free packaging complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green 3. Tape & Reel 4. See characterization specification at 105C Speed (MHz) Power Supply (V) Ordering Code(2) Package(1) Operation Range 8 2.7 - 5.5 ATmega8L-8AU ATmega8L-8AUR(3) ATmega8L-8PU ATmega8L-8MU ATmega8L-8MUR(3) 32A 32A 28P3 32M1-A 32M1-A Industrial (-40C to 85C) 16 4.5 - 5.5 ATmega8-16AU ATmega8-16AUR(3) ATmega8-16PU ATmega8-16MU ATmega8-16MUR(3) 32A 32A 28P3 32M1-A 32M1-A 8 2.7 - 5.5 ATmega8L-8AN ATmega8L-8ANR(3) ATmega8L-8PN ATmega8L-8MN ATmega8L-8MUR(3) 32A 32A 28P3 32M1-A 32M1-A Industrial (-40C to 105C) 16 4.5 - 5.5 ATmega8-16AN ATmega8-16ANR(3) ATmega8-16PN ATmega8-16MN ATmega8-16MUR(3) 32A 32A 28P3 32M1-A 32M1-A Package Type 32A 32-lead, Thin (1.0mm) Plastic Quad Flat Package (TQFP) 28P3 28-lead, 0.300” Wide, Plastic Dual Inline Package (PDIP) 32M1-A 32-pad, 5 × 5 × 1.0 body, Lead Pitch 0.50mm Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)315 2486AA–AVR–02/2013 ATmega8(L) Packaging Information 32A TITLE DRAWING NO. REV. 32A, 32-lead, 7 x 7mm body size, 1.0mm body thickness, 0.8mm lead pitch, thin profile plastic quad flat package (TQFP) 32A C 2010-10-20 PIN 1 IDENTIFIER 0°~7° PIN 1 L C A1 A2 A D1 D e E1 E B Notes: 1. This package conforms to JEDEC reference MS-026, Variation ABA. 2. Dimensions D1 and E1 do not include mold protrusion. Allowable protrusion is 0.25mm per side. Dimensions D1 and E1 are maximum plastic body size dimensions including mold mismatch. 3. Lead coplanarity is 0.10mm maximum. A – – 1.20 A1 0.05 – 0.15 A2 0.95 1.00 1.05 D 8.75 9.00 9.25 D1 6.90 7.00 7.10 Note 2 E 8.75 9.00 9.25 E1 6.90 7.00 7.10 Note 2 B 0.30 – 0.45 C 0.09 – 0.20 L 0.45 – 0.75 e 0.80 TYP COMMON DIMENSIONS (Unit of measure = mm) SYMBOL MIN NOM MAX NOTE316 2486AA–AVR–02/2013 ATmega8(L) 28P3 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 28P3, 28-lead (0.300"/7.62mm Wide) Plastic Dual Inline Package (PDIP) 28P3 B 09/28/01 PIN 1 E1 A1 B REF E B1 C L SEATING PLANE A 0º ~ 15º D e eB B2 (4 PLACES) COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE A – – 4.5724 A1 0.508 – – D 34.544 – 34.798 Note 1 E 7.620 – 8.255 E1 7.112 – 7.493 Note 1 B 0.381 – 0.533 B1 1.143 – 1.397 B2 0.762 – 1.143 L 3.175 – 3.429 C 0.203 – 0.356 eB – – 10.160 e 2.540 TYP Note: 1. Dimensions D and E1 do not include mold Flash or Protrusion. Mold Flash or Protrusion shall not exceed 0.25mm (0.010"). 317 2486AA–AVR–02/2013 ATmega8(L) 32M1-A 2325 Orchard Parkway San Jose, CA 95131 TITLE DRAWING NO. R REV. 32M1-A, 32-pad, 5 x 5 x 1.0mm Body, Lead Pitch 0.50mm, 32M1-A E 5/25/06 3.10mm Exposed Pad, Micro Lead Frame Package (MLF) COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX NOTE D1 D E1 E b e A3 A2 A1 A D2 E2 0.08 C L 1 2 3 P P 0 1 2 3 A 0.80 0.90 1.00 A1 – 0.02 0.05 A2 – 0.65 1.00 A3 0.20 REF b 0.18 0.23 0.30 D D1 D2 2.95 3.10 3.25 4.90 5.00 5.10 4.70 4.75 4.80 4.70 4.75 4.80 4.90 5.00 5.10 E E1 E2 2.95 3.10 3.25 e 0.50 BSC L 0.30 0.40 0.50 P – – 0.60 – – 12o Note: JEDEC Standard MO-220, Fig. 2 (Anvil Singulation), VHHD-2. TOP VIEW SIDE VIEW BOTTOM VIEW 0 Pin 1 ID Pin #1 Notch (0.20 R) K 0.20 – – K K318 2486AA–AVR–02/2013 ATmega8(L) Errata The revision letter in this section refers to the revision of the ATmega8 device. ATmega8 Rev. D to I, M • First Analog Comparator conversion may be delayed • Interrupts may be lost when writing the timer registers in the asynchronous timer • Signature may be Erased in Serial Programming Mode • CKOPT Does not Enable Internal Capacitors on XTALn/TOSCn Pins when 32KHz Oscillator is Used to Clock the Asynchronous Timer/Counter2 • Reading EEPROM by using ST or STS to set EERE bit triggers unexpected interrupt request 1. First Analog Comparator conversion may be delayed If the device is powered by a slow rising VCC, the first Analog Comparator conversion will take longer than expected on some devices. Problem Fix / Workaround When the device has been powered or reset, disable then enable theAnalog Comparator before the first conversion. 2. Interrupts may be lost when writing the timer registers in the asynchronous timer The interrupt will be lost if a timer register that is synchronized to the asynchronous timer clock is written when the asynchronous Timer/Counter register(TCNTx) is 0x00. Problem Fix / Workaround Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor 0x00 before writing to the asynchronous Timer Control Register(TCCRx), asynchronous Timer Counter Register(TCNTx), or asynchronous Output Compare Register(OCRx). 3. Signature may be Erased in Serial Programming Mode If the signature bytes are read before a chiperase command is completed, the signature may be erased causing the device ID and calibration bytes to disappear. This is critical, especially, if the part is running on internal RC oscillator. Problem Fix / Workaround: Ensure that the chiperase command has exceeded before applying the next command. 4. CKOPT Does not Enable Internal Capacitors on XTALn/TOSCn Pins when 32KHz Oscillator is Used to Clock the Asynchronous Timer/Counter2 When the internal RC Oscillator is used as the main clock source, it is possible to run the Timer/Counter2 asynchronously by connecting a 32KHz Oscillator between XTAL1/TOSC1 and XTAL2/TOSC2. But when the internal RC Oscillator is selected as the main clock source, the CKOPT Fuse does not control the internal capacitors on XTAL1/TOSC1 and XTAL2/TOSC2. As long as there are no capacitors connected to XTAL1/TOSC1 and XTAL2/TOSC2, safe operation of the Oscillator is not guaranteed. Problem Fix / Workaround Use external capacitors in the range of 20pF - 36pF on XTAL1/TOSC1 and XTAL2/TOSC2. This will be fixed in ATmega8 Rev. G where the CKOPT Fuse will control internal capacitors also when internal RC Oscillator is selected as main clock source. For ATmega8 Rev. G, CKOPT = 0 (programmed) will enable the internal capacitors on XTAL1 and XTAL2. Customers who want compatibility between Rev. G and older revisions, must ensure that CKOPT is unprogrammed (CKOPT = 1).319 2486AA–AVR–02/2013 ATmega8(L) 5. Reading EEPROM by using ST or STS to set EERE bit triggers unexpected interrupt request. Reading EEPROM by using the ST or STS command to set the EERE bit in the EECR register triggers an unexpected EEPROM interrupt request. Problem Fix / Workaround Always use OUT or SBI to set EERE in EECR.320 2486AA–AVR–02/2013 ATmega8(L) Datasheet Revision History Please note that the referring page numbers in this section are referred to this document. The referring revision in this section are referring to the document revision. Changes from Rev. 2486Z- 02/11 to Rev. 2486AA- 02/2013 1. Updated the datasheet according to the Atmel new Brand Style Guide. 2.Removed the reference to “On-chip debugging” from the content. 3.Added “Electrical Characteristics – TA = -40°C to 105°C” on page 242. 4.Added “ATmega8 Typical Characteristics – TA = -40°C to 105°C” on page 282. 5.Updated “Ordering Information” on page 314. Changes from Rev. 2486Y- 10/10 to Rev. 2486Z- 02/11 1. Updated the datasheet according to the Atmel new Brand Style Guide. 2. Updated “Ordering Information” on page 314. Added Ordering Information for “Tape & Reel” devices Changes from Rev. 2486X- 06/10 to Rev. 2486Y- 10/10 1. Max Rise/Fall time in Table 102 on page 239 has been corrected from 1.6ns to 1600ns. 2. Note is added to “Performing Page Erase by SPM” on page 209. 3. Updated/corrected several short-cuts and added some new ones. 4. Updated last page according to new standard. Changes from Rev. 2486W- 02/10 to Rev. 2486X- 06/10 1. Updated “DC Characteristics” on page 235 with new VOL maximum value (0.9V and 0.6V). Changes from Rev. 2486V- 05/09 to Rev. 2486W- 02/10 1. Updated “ADC Characteristics” on page 241 with VINT maximum value (2.9V). Changes from Rev. 2486U- 08/08 to Rev. 2486V- 05/09 1. Updated “Errata” on page 318. 2. Updated the last page with Atmel’s new adresses. Changes from Rev. 2486T- 05/08 to Rev. 2486U- 08/08 1. Updated “DC Characteristics” on page 235 with I CC typical values.321 2486AA–AVR–02/2013 ATmega8(L) Changes from Rev. 2486S- 08/07 to Rev. 2486T- 05/08 1. Updated Table 98 on page 233. 2. Updated “Ordering Information” on page 314. - Commercial Ordering Code removed. - No Pb-free packaging option removed. Changes from Rev. 2486R- 07/07 to Rev. 2486S- 08/07 1. Updated “Features” on page 1. 2. Added “Data Retention” on page 7. 3. Updated “Errata” on page 318. 4. Updated “Slave Mode” on page 125. Changes from Rev. 2486Q- 10/06 to Rev. 2486R- 07/07 1. Added text to Table 81 on page 211. 2. Fixed typo in “Peripheral Features” on page 1. 3. Updated Table 16 on page 42. 4. Updated Table 75 on page 199. 5. Removed redundancy and updated typo in Notes section of “DC Characteristics” on page 235. Changes from Rev. 2486P- 02/06 to Rev. 2486Q- 10/06 1. Updated “Timer/Counter Oscillator” on page 32. 2. Updated “Fast PWM Mode” on page 88. 3. Updated code example in “USART Initialization” on page 134. 4. Updated Table 37 on page 96, Table 39 on page 97, Table 42 on page 115, Table 44 on page 115, and Table 98 on page 233. 5. Updated “Errata” on page 318. Changes from Rev. 2486O-10/04 to Rev. 2486P- 02/06 1. Added “Resources” on page 7. 2. Updated “External Clock” on page 32. 3. Updated “Serial Peripheral Interface – SPI” on page 121. 4. Updated Code Example in “USART Initialization” on page 134. 5. Updated Note in “Bit Rate Generator Unit” on page 164. 6. Updated Table 98 on page 233. 7. Updated Note in Table 103 on page 241.322 2486AA–AVR–02/2013 ATmega8(L) 8. Updated “Errata” on page 318. Changes from Rev. 2486N-09/04 to Rev. 2486O-10/04 1. Removed to instances of “analog ground”. Replaced by “ground”. 2. Updated Table 7 on page 29, Table 15 on page 38, and Table 100 on page 237. 3. Updated “Calibrated Internal RC Oscillator” on page 30 with the 1MHz default value. 4. Table 89 on page 218 and Table 90 on page 218 moved to new section “Page Size” on page 218. 5. Updated descripton for bit 4 in “Store Program Memory Control Register – SPMCR” on page 206. 6. Updated “Ordering Information” on page 314. Changes from Rev. 2486M-12/03 to Rev. 2486N-09/04 1. Added note to MLF package in “Pin Configurations” on page 2. 2. Updated “Internal Voltage Reference Characteristics” on page 42. 3. Updated “DC Characteristics” on page 235. 4. ADC4 and ADC5 support 10-bit accuracy. Document updated to reflect this. Updated features in “Analog-to-Digital Converter” on page 189. Updated “ADC Characteristics” on page 241. 5. Removed reference to “External RC Oscillator application note” from “External RC Oscillator” on page 28. Changes from Rev. 2486L-10/03 to Rev. 2486M-12/03 1. Updated “Calibrated Internal RC Oscillator” on page 30. Changes from Rev. 2486K-08/03 to Rev. 2486L-10/03 1. Removed “Preliminary” and TBDs from the datasheet. 2. Renamed ICP to ICP1 in the datasheet. 3. Removed instructions CALL and JMP from the datasheet. 4. Updated tRST in Table 15 on page 38, VBG in Table 16 on page 42, Table 100 on page 237 and Table 102 on page 239. 5. Replaced text “XTAL1 and XTAL2 should be left unconnected (NC)” after Table 9 in “Calibrated Internal RC Oscillator” on page 30. Added text regarding XTAL1/XTAL2 and CKOPT Fuse in “Timer/Counter Oscillator” on page 32. 6. Updated Watchdog Timer code examples in “Timed Sequences for Changing the Configuration of the Watchdog Timer” on page 45. 7. Removed bit 4, ADHSM, from “Special Function IO Register – SFIOR” on page 58. 8. Added note 2 to Figure 103 on page 208.323 2486AA–AVR–02/2013 ATmega8(L) 9. Updated item 4 in the “Serial Programming Algorithm” on page 231. 10. Added tWD_FUSE to Table 97 on page 232 and updated Read Calibration Byte, Byte 3, in Table 98 on page 233. 11. Updated Absolute Maximum Ratings* and DC Characteristics in “Electrical Characteristics – TA = -40°C to 85°C” on page 235. Changes from Rev. 2486J-02/03 to Rev. 2486K-08/03 1. Updated VBOT values in Table 15 on page 38. 2. Updated “ADC Characteristics” on page 241. 3. Updated “ATmega8 Typical Characteristics – TA = -40°C to 85°C” on page 244. 4. Updated “Errata” on page 318. Changes from Rev. 2486I-12/02 to Rev. 2486J-02/03 1. Improved the description of “Asynchronous Timer Clock – clkASY” on page 26. 2. Removed reference to the “Multipurpose Oscillator” application note and the “32kHz Crystal Oscillator” application note, which do not exist. 3. Corrected OCn waveforms in Figure 38 on page 89. 4. Various minor Timer 1 corrections. 5. Various minor TWI corrections. 6. Added note under “Filling the Temporary Buffer (Page Loading)” on page 209 about writing to the EEPROM during an SPM Page load. 7. Removed ADHSM completely. 8. Added section “EEPROM Write during Power-down Sleep Mode” on page 23. 9. Removed XTAL1 and XTAL2 description on page 5 because they were already described as part of “Port B (PB7..PB0) XTAL1/XTAL2/TOSC1/TOSC2” on page 5. 10. Improved the table under “SPI Timing Characteristics” on page 239 and removed the table under “SPI Serial Programming Characteristics” on page 234. 11. Corrected PC6 in “Alternate Functions of Port C” on page 61. 12. Corrected PB6 and PB7 in “Alternate Functions of Port B” on page 58. 13. Corrected 230.4 Mbps to 230.4 kbps under “Examples of Baud Rate Setting” on page 153. 14. Added information about PWM symmetry for Timer 2 in “Phase Correct PWM Mode” on page 111. 15. Added thick lines around accessible registers in Figure 76 on page 163.324 2486AA–AVR–02/2013 ATmega8(L) 16. Changed “will be ignored” to “must be written to zero” for unused Z-pointer bits under “Performing a Page Write” on page 209. 17. Added note for RSTDISBL Fuse in Table 87 on page 216. 18. Updated drawings in “Packaging Information” on page 315. Changes from Rev. 2486H-09/02 to Rev. 2486I-12/02 1. Added errata for Rev D, E, and F on page 318. Changes from Rev. 2486G-09/02 to Rev. 2486H-09/02 1. Changed the Endurance on the Flash to 10,000 Write/Erase Cycles. Changes from Rev. 2486F-07/02 to Rev. 2486G-09/02 1. Updated Table 103, “ADC Characteristics,” on page 241. Changes from Rev. 2486E-06/02 to Rev. 2486F-07/02 1. Changes in “Digital Input Enable and Sleep Modes” on page 55. 2. Addition of OCS2 in “MOSI/OC2 – Port B, Bit 3” on page 59. 3. The following tables have been updated: Table 51, “CPOL and CPHA Functionality,” on page 127, Table 59, “UCPOL Bit Settings,” on page 152, Table 72, “Analog Comparator Multiplexed Input(1),” on page 188, Table 73, “ADC Conversion Time,” on page 193, Table 75, “Input Channel Selections,” on page 199, and Table 84, “Explanation of Different Variables used in Figure 103 on page 208 and the Mapping to the Z-pointer,” on page 214. 4. Changes in “Reading the Calibration Byte” on page 227. 5. Corrected Errors in Cross References. Changes from Rev. 2486D-03/02 to Rev. 2486E-06/02 1. Updated Some Preliminary Test Limits and Characterization Data The following tables have been updated: Table 15, “Reset Characteristics,” on page 38, Table 16, “Internal Voltage Reference Characteristics,” on page 42, DC Characteristics on page 235, Table , “ADC Characteristics,” on page 241. 2. Changes in External Clock Frequency Added the description at the end of “External Clock” on page 32. Added period changing data in Table 99, “External Clock Drive,” on page 237. 3. Updated TWI Chapter More details regarding use of the TWI bit rate prescaler and a Table 65, “TWI Bit Rate Prescaler,” on page 167.325 2486AA–AVR–02/2013 ATmega8(L) Changes from Rev. 2486C-03/02 to Rev. 2486D-03/02 1. Updated Typical Start-up Times. The following tables has been updated: Table 5, “Start-up Times for the Crystal Oscillator Clock Selection,” on page 28, Table 6, “Start-up Times for the Low-frequency Crystal Oscillator Clock Selection,” on page 28, Table 8, “Start-up Times for the External RC Oscillator Clock Selection,” on page 29, and Table 12, “Start-up Times for the External Clock Selection,” on page 32. 2. Added “ATmega8 Typical Characteristics – TA = -40°C to 85°C” on page 244. Changes from Rev. 2486B-12/01 to Rev. 2486C-03/02 1. Updated TWI Chapter. More details regarding use of the TWI Power-down operation and using the TWI as Master with low TWBRR values are added into the datasheet. Added the note at the end of the “Bit Rate Generator Unit” on page 164. Added the description at the end of “Address Match Unit” on page 164. 2. Updated Description of OSCCAL Calibration Byte. In the datasheet, it was not explained how to take advantage of the calibration bytes for 2, 4, and 8MHz Oscillator selections. This is now added in the following sections: Improved description of “Oscillator Calibration Register – OSCCAL” on page 31 and “Calibration Byte” on page 218. 3. Added Some Preliminary Test Limits and Characterization Data. Removed some of the TBD’s in the following tables and pages: Table 3 on page 26, Table 15 on page 38, Table 16 on page 42, Table 17 on page 44, “TA = -40°C to +85°C, VCC = 2.7V to 5.5V (unless otherwise noted)” on page 235, Table 99 on page 237, and Table 102 on page 239. 4. Updated Programming Figures. Figure 104 on page 219 and Figure 112 on page 230 are updated to also reflect that AVCC must be connected during Programming mode. 5. Added a Description on how to Enter Parallel Programming Mode if RESET Pin is Disabled or if External Oscillators are Selected. Added a note in section “Enter Programming Mode” on page 221.1 2486AA–AVR–02/2013 ATmega8(L) Table of Contents Features 1 Pin Configurations 2 Overview 3 Block Diagram 3 Disclaimer 4 Pin Descriptions 5 Resources 7 Data Retention 7 About Code Examples 8 Atmel AVR CPU Core 9 Introduction 9 Architectural Overview 9 Arithmetic Logic Unit – ALU 11 Status Register 11 General Purpose Register File 12 Stack Pointer 13 Instruction Execution Timing 13 Reset and Interrupt Handling 14 AVR ATmega8 Memories 17 In-System Reprogrammable Flash Program Memory 17 SRAM Data Memory 18 Data Memory Access Times 19 EEPROM Data Memory 19 I/O Memory 24 System Clock and Clock Options 25 Clock Systems and their Distribution 25 Clock Sources 26 Crystal Oscillator 27 Low-frequency Crystal Oscillator 28 External RC Oscillator 28 Calibrated Internal RC Oscillator 30 External Clock 32 Timer/Counter Oscillator 32 Power Management and Sleep Modes 33 Idle Mode 342 2486AA–AVR–02/2013 ATmega8(L) ADC Noise Reduction Mode 34 Power-down Mode 34 Power-save Mode 34 Standby Mode 35 Minimizing Power Consumption 35 System Control and Reset 37 Internal Voltage Reference 42 Watchdog Timer 43 Timed Sequences for Changing the Configuration of the Watchdog Timer 45 Interrupts 46 Interrupt Vectors in ATmega8 46 I/O Ports 51 Introduction 51 Ports as General Digital I/O 52 Alternate Port Functions 56 Register Description for I/O Ports 65 External Interrupts 66 8-bit Timer/Counter0 69 Overview 69 Timer/Counter Clock Sources 70 Counter Unit 70 Operation 70 Timer/Counter Timing Diagrams 70 8-bit Timer/Counter Register Description 71 Timer/Counter0 and Timer/Counter1 Prescalers 73 16-bit Timer/Counter1 75 Overview 75 Accessing 16-bit Registers 77 Timer/Counter Clock Sources 80 Counter Unit 80 Input Capture Unit 81 Output Compare Units 83 Compare Match Output Unit 85 Modes of Operation 87 Timer/Counter Timing Diagrams 94 16-bit Timer/Counter Register Description 96 8-bit Timer/Counter2 with PWM and Asynchronous Operation 102 Overview 1023 2486AA–AVR–02/2013 ATmega8(L) Timer/Counter Clock Sources 103 Counter Unit 104 Output Compare Unit 105 Compare Match Output Unit 107 Modes of Operation 108 Timer/Counter Timing Diagrams 112 8-bit Timer/Counter Register Description 114 Asynchronous Operation of the Timer/Counter 117 Timer/Counter Prescaler 120 Serial Peripheral Interface – SPI 121 SS Pin Functionality 125 Data Modes 127 USART 129 Overview 129 Clock Generation 130 Frame Formats 133 USART Initialization 134 Data Transmission – The USART Transmitter 136 Data Reception – The USART Receiver 138 Asynchronous Data Reception 142 Multi-processor Communication Mode 145 Accessing UBRRH/UCSRC Registers 146 USART Register Description 148 Examples of Baud Rate Setting 153 Two-wire Serial Interface 157 Features 157 Two-wire Serial Interface Bus Definition 157 Data Transfer and Frame Format 158 Multi-master Bus Systems, Arbitration and Synchronization 161 Overview of the TWI Module 163 TWI Register Description 165 Using the TWI 168 Transmission Modes 171 Multi-master Systems and Arbitration 184 Analog Comparator 186 Analog Comparator Multiplexed Input 188 Analog-to-Digital Converter 189 Features 189 Starting a Conversion 191 Prescaling and Conversion Timing 191 Changing Channel or Reference Selection 1944 2486AA–AVR–02/2013 ATmega8(L) ADC Noise Canceler 195 ADC Conversion Result 199 Boot Loader Support – Read-While-Write Self-Programming 202 Boot Loader Features 202 Application and Boot Loader Flash Sections 202 Read-While-Write and No Read-While-Write Flash Sections 202 Boot Loader Lock Bits 204 Entering the Boot Loader Program 205 Addressing the Flash During Self-Programming 207 Self-Programming the Flash 208 Memory Programming 215 Program And Data Memory Lock Bits 215 Fuse Bits 216 Signature Bytes 218 Calibration Byte 218 Page Size 218 Parallel Programming Parameters, Pin Mapping, and Commands 219 Parallel Programming 221 Serial Downloading 230 Serial Programming Pin Mapping 230 Electrical Characteristics – TA = -40°C to 85°C 235 Absolute Maximum Ratings* 235 DC Characteristics 235 External Clock Drive Waveforms 237 External Clock Drive 237 Two-wire Serial Interface Characteristics 238 SPI Timing Characteristics 239 ADC Characteristics 241 Electrical Characteristics – TA = -40°C to 105°C 242 Absolute Maximum Ratings* 242 DC Characteristics TA = -40C to 105C, VCC = 2.7V to 5.5V (unless otherwise noted) 242 ATmega8 Typical Characteristics – TA = -40°C to 85°C 244 ATmega8 Typical Characteristics – TA = -40°C to 105°C 282 Active Supply Current 282 Idle Supply Current 284 Power-down Supply Current 286 Pin Pull-up 287 Pin Driver Strength 289 Pin Thresholds and Hysteresis 2935 2486AA–AVR–02/2013 ATmega8(L) Bod Thresholds and Analog Comparator Offset 298 Internal Oscillator Speed 300 Current Consumption of Peripheral Units 305 Current Consumption in Reset and Reset Pulsewidth 308 Register Summary 309 Instruction Set Summary 311 Ordering Information 314 Packaging Information 315 32A 315 28P3 316 32M1-A 317 Errata 318 ATmega8 Rev. D to I, M 318 Datasheet Revision History 320 Changes from Rev. 2486Z- 02/11 to Rev. 2486AA- 02/2013 320 Changes from Rev. 2486Y- 10/10 to Rev. 2486Z- 02/11 320 Changes from Rev. 2486X- 06/10 to Rev. 2486Y- 10/10 320 Changes from Rev. 2486W- 02/10 to Rev. 2486X- 06/10 320 Changes from Rev. 2486V- 05/09 to Rev. 2486W- 02/10 320 Changes from Rev. 2486U- 08/08 to Rev. 2486V- 05/09 320 Changes from Rev. 2486T- 05/08 to Rev. 2486U- 08/08 320 Changes from Rev. 2486S- 08/07 to Rev. 2486T- 05/08 321 Changes from Rev. 2486R- 07/07 to Rev. 2486S- 08/07 321 Changes from Rev. 2486Q- 10/06 to Rev. 2486R- 07/07 321 Changes from Rev. 2486P- 02/06 to Rev. 2486Q- 10/06 321 Changes from Rev. 2486O-10/04 to Rev. 2486P- 02/06 321 Changes from Rev. 2486N-09/04 to Rev. 2486O-10/04 322 Changes from Rev. 2486M-12/03 to Rev. 2486N-09/04 322 Changes from Rev. 2486L-10/03 to Rev. 2486M-12/03 322 Changes from Rev. 2486K-08/03 to Rev. 2486L-10/03 322 Changes from Rev. 2486J-02/03 to Rev. 2486K-08/03 323 Changes from Rev. 2486I-12/02 to Rev. 2486J-02/03 323 Changes from Rev. 2486H-09/02 to Rev. 2486I-12/02 324 Changes from Rev. 2486G-09/02 to Rev. 2486H-09/02 324 Changes from Rev. 2486F-07/02 to Rev. 2486G-09/02 324 Changes from Rev. 2486E-06/02 to Rev. 2486F-07/02 324 Changes from Rev. 2486D-03/02 to Rev. 2486E-06/02 324 Changes from Rev. 2486C-03/02 to Rev. 2486D-03/02 325 Changes from Rev. 2486B-12/01 to Rev. 2486C-03/02 3252486AA–AVR–02/2013 Atmel Corporation 1600 Technology Drive San Jose, CA 95110 USA Tel: (+1) (408) 441-0311 Fax: (+1) (408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Roa Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan G.K. 16F Shin-Osaki Kangyo Bldg 1-6-4 Osaki, Shinagawa-ku Tokyo 141-0032 JAPAN Tel: (+81) (3) 6417-0300 Fax: (+81) (3) 6417-0370 © 2013 Atmel Corporation. All rights reserved. / Rev.: 2486AA–AVR–02/2013 Atmel®, Atmel logo and combinations thereof, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. Table of Contents 1 8127F–AVR–02/2013 Features • High Performance, Low Power AVR® 8-Bit Microcontroller • Advanced RISC Architecture – 54 Powerful Instructions – Most Single Clock Cycle Execution – 16 x 8 General Purpose Working Registers – Fully Static Operation – Up to 12 MIPS Throughput at 12 MHz • Non-volatile Program and Data Memories – 512/1024 Bytes of In-System Programmable Flash Program Memory – 32 Bytes Internal SRAM – Flash Write/Erase Cycles: 10,000 – Data Retention: 20 Years at 85oC / 100 Years at 25oC • Peripheral Features – QTouch® Library Support for Capacitive Touch Sensing (1 Channel) – One 16-bit Timer/Counter with Prescaler and Two PWM Channels – Programmable Watchdog Timer with Separate On-chip Oscillator – 4-channel, 8-bit Analog to Digital Converter (ATtiny5/10, only) – On-chip Analog Comparator • Special Microcontroller Features – In-System Programmable (at 5V, only) – External and Internal Interrupt Sources – Low Power Idle, ADC Noise Reduction, and Power-down Modes – Enhanced Power-on Reset Circuit – Programmable Supply Voltage Level Monitor with Interrupt and Reset – Internal Calibrated Oscillator • I/O and Packages – Four Programmable I/O Lines – 6-pin SOT and 8-pad UDFN • Operating Voltage: – 1.8 – 5.5V • Programming Voltage: – 5V • Speed Grade – 0 – 4 MHz @ 1.8 – 5.5V – 0 – 8 MHz @ 2.7 – 5.5V – 0 – 12 MHz @ 4.5 – 5.5V • Industrial and Extended Temperature Ranges • Low Power Consumption – Active Mode: • 200µA at 1MHz and 1.8V – Idle Mode: • 25µA at 1MHz and 1.8V – Power-down Mode: • < 0.1µA at 1.8V Atmel 8-bit AVR Microcontroller with 512/1024 Bytes In-System Programmable Flash ATtiny4 / ATtiny5 / ATtiny9 / ATtiny10 Rev. 8127F–AVR–02/2013ATtiny4/5/9/10 [DATASHEET] 2 8127F–AVR–02/2013 1. Pin Configurations Figure 1-1. Pinout of ATtiny4/5/9/10 1.1 Pin Description 1.1.1 VCC Supply voltage. 1.1.2 GND Ground. 1.1.3 Port B (PB3..PB0) This is a 4-bit, bi-directional I/O port with internal pull-up resistors, individually selectable for each bit. The output buffers have symmetrical drive characteristics, with both high sink and source capability. As inputs, the port pins that are externally pulled low will source current if pull-up resistors are activated. Port pins are tri-stated when a reset condition becomes active, even if the clock is not running. The port also serves the functions of various special features of the ATtiny4/5/9/10, as listed on page 36. 1.1.4 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running and provided the reset pin has not been disabled. The minimum pulse length is given in Table 16-4 on page 118. Shorter pulses are not guaranteed to generate a reset. The reset pin can also be used as a (weak) I/O pin. 1 2 3 6 5 4 (PCINT0/TPIDATA/OC0A/ADC0/AIN0) PB0 GND (PCINT1/TPICLK/CLKI/ICP0/OC0B/ADC1/AIN1) PB1 PB3 (RESET/PCINT3/ADC3) VCC PB2 (T0/CLKO/PCINT2/INT0/ADC2) SOT-23 1 2 3 4 8 7 6 5 (PCINT1/TPICLK/CLKI/ICP0/OC0B/ADC1/AIN1) PB1 NC NC GND PB2 (T0/CLKO/PCINT2/INT0/ADC2) VCC PB3 (RESET/PCINT3/ADC3) PB0 (AIN0/ADC0/OC0A/TPIDATA/PCINT0) UDFNATtiny4/5/9/10 [DATASHEET] 3 8127F–AVR–02/2013 2. Overview ATtiny4/5/9/10 are low-power CMOS 8-bit microcontrollers based on the compact AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny4/5/9/10 achieve throughputs approaching 1 MIPS per MHz, allowing the system designer to optimize power consumption versus processing speed. Figure 2-1. Block Diagram The AVR core combines a rich instruction set with 16 general purpose working registers and system registers. All registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is compact and code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The ATtiny4/5/9/10 provide the following features: 512/1024 byte of In-System Programmable Flash, 32 bytes of SRAM, four general purpose I/O lines, 16 general purpose working registers, a 16-bit timer/counter with two PWM STACK POINTER SRAM PROGRAM COUNTER PROGRAMMING LOGIC ISP INTERFACE INTERNAL OSCILLATOR WATCHDOG TIMER RESET FLAG REGISTER MCU STATUS REGISTER TIMER/ COUNTER0 CALIBRATED OSCILLATOR TIMING AND CONTROL INTERRUPT UNIT ANALOG COMPARATOR ADC GENERAL PURPOSE REGISTERS X Y Z ALU STATUS REGISTER PROGRAM FLASH INSTRUCTION REGISTER INSTRUCTION DECODER CONTROL LINES VCC RESET DATA REGISTER PORT B DIRECTION REG. PORT B DRIVERS PORT B GND PB3:0 8-BIT DATA BUSATtiny4/5/9/10 [DATASHEET] 4 8127F–AVR–02/2013 channels, internal and external interrupts, a programmable watchdog timer with internal oscillator, an internal calibrated oscillator, and four software selectable power saving modes. ATtiny5/10 are also equipped with a fourchannel, 8-bit Analog to Digital Converter (ADC). Idle mode stops the CPU while allowing the SRAM, timer/counter, ADC (ATtiny5/10, only), analog comparator, and interrupt system to continue functioning. ADC Noise Reduction mode minimizes switching noise during ADC conversions by stopping the CPU and all I/O modules except the ADC. In Power-down mode registers keep their contents and all chip functions are disabled until the next interrupt or hardware reset. In Standby mode, the oscillator is running while the rest of the device is sleeping, allowing very fast start-up combined with low power consumption. The device is manufactured using Atmel’s high density non-volatile memory technology. The on-chip, in-system programmable Flash allows program memory to be re-programmed in-system by a conventional, non-volatile memory programmer. The ATtiny4/5/9/10 AVR are supported by a suite of program and system development tools, including macro assemblers and evaluation kits. 2.1 Comparison of ATtiny4, ATtiny5, ATtiny9 and ATtiny10 A comparison of the devices is shown in Table 2-1. Table 2-1. Differences between ATtiny4, ATtiny5, ATtiny9 and ATtiny10 Device Flash ADC Signature ATtiny4 512 bytes No 0x1E 0x8F 0x0A ATtiny5 512 bytes Yes 0x1E 0x8F 0x09 ATtiny9 1024 bytes No 0x1E 0x90 0x08 ATtiny10 1024 bytes Yes 0x1E 0x90 0x03ATtiny4/5/9/10 [DATASHEET] 5 8127F–AVR–02/2013 3. General Information 3.1 Resources A comprehensive set of drivers, application notes, data sheets and descriptions on development tools are available for download at http://www.atmel.com/microcontroller/avr. 3.2 Code Examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. 3.3 Capacitive Touch Sensing Atmel QTouch Library provides a simple to use solution for touch sensitive interfaces on Atmel AVR microcontrollers. The QTouch Library includes support for QTouch® and QMatrix® acquisition methods. Touch sensing is easily added to any application by linking the QTouch Library and using the Application Programming Interface (API) of the library to define the touch channels and sensors. The application then calls the API to retrieve channel information and determine the state of the touch sensor. The QTouch Library is free and can be downloaded from the Atmel website. For more information and details of implementation, refer to the QTouch Library User Guide – also available from the Atmel website. 3.4 Data Retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C.ATtiny4/5/9/10 [DATASHEET] 6 8127F–AVR–02/2013 4. CPU Core This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. 4.1 Architectural Overview Figure 4-1. Block Diagram of the AVR Architecture In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is In-System reprogrammable Flash memory. The fast-access Register File contains 16 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Flash Program Memory Instruction Register Instruction Decoder Program Counter Control Lines 16 x 8 General Purpose Registrers ALU Status and Control I/O Lines Data Bus 8-bit Data SRAM Direct Addressing Indirect Addressing Interrupt Unit Watchdog Timer Analog Comparator Timer/Counter 0 ADCATtiny4/5/9/10 [DATASHEET] 7 8127F–AVR–02/2013 Six of the 16 registers can be used as three 16-bit indirect address register pointers for data space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, capable of directly addressing the whole address space. Most AVR instructions have a single 16-bit word format but 32-bit wide instructions also exist. The actual instruction set varies, as some devices only implement a part of the instruction set. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the four different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O memory can be accessed as the data space locations, 0x0000 - 0x003F. 4.2 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 16 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bitfunctions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for a detailed description. 4.3 Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in document “AVR Instruction Set” and section “Instruction Set Summary” on page 150. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software. 4.4 General Purpose Register File The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the Register File: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • One 16-bit output operand and one 16-bit result inputATtiny4/5/9/10 [DATASHEET] 8 8127F–AVR–02/2013 Figure 4-2 below shows the structure of the 16 general purpose working registers in the CPU. Figure 4-2. AVR CPU General Purpose Working Registers Note: A typical implementation of the AVR register file includes 32 general prupose registers but ATtiny4/5/9/10 implement only 16 registers. For reasons of compatibility the registers are numbered R16...R31, not R0...R15. Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. 4.4.1 The X-register, Y-register, and Z-register Registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 4-3. Figure 4-3. The X-, Y-, and Z-registers 7 0 R16 R17 General R18 Purpose … Working R26 X-register Low Byte Registers R27 X-register High Byte R28 Y-register Low Byte R29 Y-register High Byte R30 Z-register Low Byte R31 Z-register High Byte 15 XH XL 0 X-register 7 07 0 R27 R26 15 YH YL 0 Y-register 7 07 0 R29 R28 15 ZH ZL 0 Z-register 7 07 0 R31 R30ATtiny4/5/9/10 [DATASHEET] 9 8127F–AVR–02/2013 In different addressing modes these address registers function as automatic increment and automatic decrement (see document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for details). 4.5 Stack Pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x40. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when data is popped from the Stack with return from subroutine RET or return from interrupt RETI. The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. 4.6 Instruction Execution Timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 4-4. The Parallel Instruction Fetches and Instruction Executions Figure 4-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. Figure 4-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. clk 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch T1 T2 T3 T4 CPUATtiny4/5/9/10 [DATASHEET] 10 8127F–AVR–02/2013 Figure 4-5. Single Cycle ALU Operation 4.7 Reset and Interrupt Handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate Program Vector in the program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. The lowest addresses in the program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 35. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back T1 T2 T3 T4 clkCPUATtiny4/5/9/10 [DATASHEET] 11 8127F–AVR–02/2013 When using the SEI instruction to enable interrupts, the instruction following SEI will be executed before any pending interrupts, as shown in the following example. Note: See “Code Examples” on page 5. 4.7.1 Interrupt Response Time The interrupt execution response for all the enabled AVR interrupts is four clock cycles minimum. After four clock cycles the Program Vector address for the actual interrupt handling routine is executed. During this four clock cycle period, the Program Counter is pushed onto the Stack. The vector is normally a jump to the interrupt routine, and this jump takes three clock cycles. If an interrupt occurs during execution of a multi-cycle instruction, this instruction is completed before the interrupt is served. If an interrupt occurs when the MCU is in sleep mode, the interrupt execution response time is increased by four clock cycles. This increase comes in addition to the start-up time from the selected sleep mode. A return from an interrupt handling routine takes four clock cycles. During these four clock cycles, the Program Counter (two bytes) is popped back from the Stack, the Stack Pointer is incremented by two, and the I-bit in SREG is set. 4.8 Register Description 4.8.1 CCP – Configuration Change Protection Register • Bits 7:0 – CCP[7:0] – Configuration Change Protection In order to change the contents of a protected I/O register the CCP register must first be written with the correct signature. After CCP is written the protected I/O registers may be written to during the next four CPU instruction cycles. All interrupts are ignored during these cycles. After these cycles interrupts are automatically handled again by the CPU, and any pending interrupts will be executed according to their priority. When the protected I/O register signature is written, CCP[0] will read as one as long as the protected feature is enabled, while CCP[7:1] will always read as zero. Table 4-1 shows the signatures that are in recognised. Assembly Code Example sei ; set Global Interrupt Enable sleep ; enter sleep, waiting for interrupt ; note: will enter sleep before any pending interrupt(s) Bit 7 6 5 4 3 2 1 0 0x3C CCP[7:0] CCP Read/Write W W W W W W W R/W Initial Value 0 0 0 0 0 0 0 0 Table 4-1. Signatures Recognised by the Configuration Change Protection Register Signature Group Description 0xD8 IOREG: CLKMSR, CLKPSR, WDTCSR Protected I/O registerATtiny4/5/9/10 [DATASHEET] 12 8127F–AVR–02/2013 4.8.2 SPH and SPL — Stack Pointer Register 4.8.3 SREG – Status Register • Bit 7 – I: Global Interrupt Enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the document “AVR Instruction Set” and “Instruction Set Summary” on page 150. • Bit 6 – T: Bit Copy Storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half Carry Flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry is useful in BCD arithmetic. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for detailed information. • Bit 4 – S: Sign Bit, S = N V The S-bit is always an exclusive or between the Negative Flag N and the Two’s Complement Overflow Flag V. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for detailed information. • Bit 3 – V: Two’s Complement Overflow Flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for detailed information. • Bit 2 – N: Negative Flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for detailed information. • Bit 1 – Z: Zero Flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for detailed information. Bit 15 14 13 12 11 10 9 8 0x3E SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 SPH 0x3D SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL 76543210 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND Initial Value RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND Bit 7 6 5 4 3 2 1 0 0x3F I T H S V N Z C SREG Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny4/5/9/10 [DATASHEET] 13 8127F–AVR–02/2013 • Bit 0 – C: Carry Flag The Carry Flag C indicates a carry in an arithmetic or logic operation. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for detailed information.ATtiny4/5/9/10 [DATASHEET] 14 8127F–AVR–02/2013 5. Memories This section describes the different memories in the ATtiny4/5/9/10. Devices have two main memory areas, the program memory space and the data memory space. 5.1 In-System Re-programmable Flash Program Memory The ATtiny4/5/9/10 contain 512/1024 bytes of on-chip, in-system reprogrammable Flash memory for program storage. Since all AVR instructions are 16 or 32 bits wide, the Flash is organized as 256/512 x 16. The Flash memory has an endurance of at least 10,000 write/erase cycles. The ATtiny4/5/9/10 Program Counter (PC) is 9 bits wide, thus capable of addressing the 256/512 program memory locations, starting at 0x000. “Memory Programming” on page 106 contains a detailed description on Flash data serial downloading. Constant tables can be allocated within the entire address space of program memory. Since program memory can not be accessed directly, it has been mapped to the data memory. The mapped program memory begins at byte address 0x4000 in data memory (see Figure 5-1 on page 15). Although programs are executed starting from address 0x000 in program memory it must be addressed starting from 0x4000 when accessed via the data memory. Internal write operations to Flash program memory have been disabled and program memory therefore appears to firmware as read-only. Flash memory can still be written to externally but internal write operations to the program memory area will not be succesful. Timing diagrams of instruction fetch and execution are presented in “Instruction Execution Timing” on page 9. 5.2 Data Memory Data memory locations include the I/O memory, the internal SRAM memory, the non-volatile memory lock bits, and the Flash memory. See Figure 5-1 on page 15 for an illustration on how the ATtiny4/5/9/10 memory space is organized. The first 64 locations are reserved for I/O memory, while the following 32 data memory locations address the internal data SRAM. The non-volatile memory lock bits and all the Flash memory sections are mapped to the data memory space. These locations appear as read-only for device firmware. The four different addressing modes for data memory are direct, indirect, indirect with pre-decrement, and indirect with post-increment. In the register file, registers R26 to R31 function as pointer registers for indirect addressing. The IN and OUT instructions can access all 64 locations of I/O memory. Direct addressing using the LDS and STS instructions reaches the 128 locations between 0x0040 and 0x00BF. The indirect addressing reaches the entire data memory space. When using indirect addressing modes with automatic pre-decrement and post-increment, the address registers X, Y, and Z are decremented or incremented.ATtiny4/5/9/10 [DATASHEET] 15 8127F–AVR–02/2013 Figure 5-1. Data Memory Map (Byte Addressing) 5.2.1 Data Memory Access Times This section describes the general access timing concepts for internal memory access. The internal data SRAM access is performed in two clkCPU cycles as described in Figure 5-2. Figure 5-2. On-chip Data SRAM Access Cycles 0x0000 ... 0x003F 0x0040 ... 0x005F 0x0060 ... 0x3EFF 0x3F00 ... 0x3F01 0x3F02 ... 0x3F3F 0x3F40 ... 0x3F41 0x3F42 ... 0x3F7F 0x3F80 ... 0x3F81 0x3F82 ... 0x3FBF 0x3FC0 ... 0x3FC3 0x3FC4 ... 0x3FFF 0x4000 ... 0x41FF/0x43FF 0x4400 ... 0xFFFF I/O SPACE SRAM DATA MEMORY (reserved) NVM LOCK BITS (reserved) CONFIGURATION BITS (reserved) CALIBRATION BITS (reserved) DEVICE ID BITS (reserved) FLASH PROGRAM MEMORY (reserved) clk WR RD Data Data Address Address valid T1 T2 T3 Compute Address Read Write CPU Memory Access Instruction Next InstructionATtiny4/5/9/10 [DATASHEET] 16 8127F–AVR–02/2013 5.3 I/O Memory The I/O space definition of the ATtiny4/5/9/10 is shown in “Register Summary” on page 148. All ATtiny4/5/9/10 I/Os and peripherals are placed in the I/O space. All I/O locations may be accessed using the LD and ST instructions, enabling data transfer between the 16 general purpose working registers and the I/O space. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. See document “AVR Instruction Set” and section “Instruction Set Summary” on page 150 for more details. When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. Some of the status flags are cleared by writing a logical one to them. Note that CBI and SBI instructions will only operate on the specified bit, and can therefore be used on registers containing such status flags. The CBI and SBI instructions work on registers in the address range 0x00 to 0x1F, only. The I/O and Peripherals Control Registers are explained in later sections.ATtiny4/5/9/10 [DATASHEET] 17 8127F–AVR–02/2013 6. Clock System Figure 6-1 presents the principal clock systems and their distribution in ATtiny4/5/9/10. All of the clocks need not be active at a given time. In order to reduce power consumption, the clocks to modules not being used can be halted by using different sleep modes and power reduction register bits, as described in “Power Management and Sleep Modes” on page 23. The clock systems is detailed below. Figure 6-1. Clock Distribution 6.1 Clock Subsystems The clock subsystems are detailed in the sections below. 6.1.1 CPU Clock – clkCPU The CPU clock is routed to parts of the system concerned with operation of the AVR Core. Examples of such modules are the General Purpose Register File, the System Registers and the SRAM data memory. Halting the CPU clock inhibits the core from performing general operations and calculations. 6.1.2 I/O Clock – clkI/O The I/O clock is used by the majority of the I/O modules, like Timer/Counter. The I/O clock is also used by the External Interrupt module, but note that some external interrupts are detected by asynchronous logic, allowing such interrupts to be detected even if the I/O clock is halted. 6.1.3 NVM clock - clkNVM The NVM clock controls operation of the Non-Volatile Memory Controller. The NVM clock is usually active simultaneously with the CPU clock. CLOCK CONTROL UNIT GENERAL I/O MODULES ANALOG-TO-DIGITAL CONVERTER CPU CORE WATCHDOG TIMER RESET LOGIC CLOCK PRESCALER RAM CLOCK SWITCH NVM CALIBRATED OSCILLATOR clk ADC SOURCE CLOCK clk I/O clk CPU clk NVM WATCHDOG CLOCK WATCHDOG OSCILLATOR EXTERNAL CLOCKATtiny4/5/9/10 [DATASHEET] 18 8127F–AVR–02/2013 6.1.4 ADC Clock – clkADC The ADC is provided with a dedicated clock domain. This allows halting the CPU and I/O clocks in order to reduce noise generated by digital circuitry. This gives more accurate ADC conversion results. The ADC is available in ATtiny5/10, only. 6.2 Clock Sources All synchronous clock signals are derived from the main clock. The device has three alternative sources for the main clock, as follows: • Calibrated Internal 8 MHz Oscillator (see page 18) • External Clock (see page 18) • Internal 128 kHz Oscillator (see page 19) See Table 6-3 on page 21 on how to select and change the active clock source. 6.2.1 Calibrated Internal 8 MHz Oscillator The calibrated internal oscillator provides an approximately 8 MHz clock signal. Though voltage and temperature dependent, this clock can be very accurately calibrated by the user. See Table 16-2 on page 117, Figure 17-39 on page 141 and Figure 17-40 on page 141 for more details. This clock may be selected as the main clock by setting the Clock Main Select bits CLKMS[1:0] in CLKMSR to 0b00. Once enabled, the oscillator will operate with no external components. During reset, hardware loads the calibration byte into the OSCCAL register and thereby automatically calibrates the oscillator. The accuracy of this calibration is shown as Factory calibration in Table 16-2 on page 117. When this oscillator is used as the main clock, the watchdog oscillator will still be used for the watchdog timer and reset time-out. For more information on the pre-programmed calibration value, see section “Calibration Section” on page 109. 6.2.2 External Clock To use the device with an external clock source, CLKI should be driven as shown in Figure 6-2. The external clock is selected as the main clock by setting CLKMS[1:0] bits in CLKMSR to 0b10. Figure 6-2. External Clock Drive Configuration When applying an external clock, it is required to avoid sudden changes in the applied clock frequency to ensure stable operation of the MCU. A variation in frequency of more than 2% from one clock cycle to the next can lead to unpredictable behavior. It is required to ensure that the MCU is kept in reset during such changes in the clock frequency. EXTERNAL CLOCK SIGNAL CLKI GNDATtiny4/5/9/10 [DATASHEET] 19 8127F–AVR–02/2013 6.2.3 Internal 128 kHz Oscillator The internal 128 kHz oscillator is a low power oscillator providing a clock of 128 kHz. The frequency depends on supply voltage, temperature and batch variations. This clock may be select as the main clock by setting the CLKMS[1:0] bits in CLKMSR to 0b01. 6.2.4 Switching Clock Source The main clock source can be switched at run-time using the “CLKMSR – Clock Main Settings Register” on page 21. When switching between any clock sources, the clock system ensures that no glitch occurs in the main clock. 6.2.5 Default Clock Source The calibrated internal 8 MHz oscillator is always selected as main clock when the device is powered up or has been reset. The synchronous system clock is the main clock divided by 8, controlled by the System Clock Prescaler. The Clock Prescaler Select Bits can be written later to change the system clock frequency. See “System Clock Prescaler”. 6.3 System Clock Prescaler The system clock is derived from the main clock via the System Clock Prescaler. The system clock can be divided by setting the “CLKPSR – Clock Prescale Register” on page 22. The system clock prescaler can be used to decrease power consumption at times when requirements for processing power is low or to bring the system clock within limits of maximum frequency. The prescaler can be used with all main clock source options, and it will affect the clock frequency of the CPU and all synchronous peripherals. The System Clock Prescaler can be used to implement run-time changes of the internal clock frequency while still ensuring stable operation. 6.3.1 Switching Prescaler Setting When switching between prescaler settings, the system clock prescaler ensures that no glitch occurs in the system clock and that no intermediate frequency is higher than neither the clock frequency corresponding the previous setting, nor the clock frequency corresponding to the new setting. The ripple counter that implements the prescaler runs at the frequency of the main clock, which may be faster than the CPU's clock frequency. Hence, it is not possible to determine the state of the prescaler - even if it were readable, and the exact time it takes to switch from one clock division to another cannot be exactly predicted. From the time the CLKPS values are written, it takes between T1 + T2 and T1 + 2*T2 before the new clock frequency is active. In this interval, two active clock edges are produced. Here, T1 is the previous clock period, and T2 is the period corresponding to the new prescaler setting.ATtiny4/5/9/10 [DATASHEET] 20 8127F–AVR–02/2013 6.4 Starting 6.4.1 Starting from Reset The internal reset is immediately asserted when a reset source goes active. The internal reset is kept asserted until the reset source is released and the start-up sequence is completed. The start-up sequence includes three steps, as follows. 1. The first step after the reset source has been released consists of the device counting the reset start-up time. The purpose of this reset start-up time is to ensure that supply voltage has reached sufficient levels. The reset start-up time is counted using the internal 128 kHz oscillator. See Table 6-1 for details of reset start-up time. Note that the actual supply voltage is not monitored by the start-up logic. The device will count until the reset start-up time has elapsed even if the device has reached sufficient supply voltage levels earlier. 2. The second step is to count the oscillator start-up time, which ensures that the calibrated internal oscillator has reached a stable state before it is used by the other parts of the system. The calibrated internal oscillator needs to oscillate for a minimum number of cycles before it can be considered stable. See Table 6-1 for details of the oscillator start-up time. 3. The last step before releasing the internal reset is to load the calibration and the configuration values from the Non-Volatile Memory to configure the device properly. The configuration time is listed in Table 6-1. Notes: 1. After powering up the device or after a reset the system clock is automatically set to calibrated internal 8 MHz oscillator, divided by 8 6.4.2 Starting from Power-Down Mode When waking up from Power-Down sleep mode, the supply voltage is assumed to be at a sufficient level and only the oscillator start-up time is counted to ensure the stable operation of the oscillator. The oscillator start-up time is counted on the selected main clock, and the start-up time depends on the clock selected. See Table 6-2 for details. Notes: 1. The start-up time is measured in main clock oscillator cycles. 6.4.3 Starting from Idle / ADC Noise Reduction / Standby Mode When waking up from Idle, ADC Noise Reduction or Standby Mode, the oscillator is already running and no oscillator start-up time is introduced. The ADC is available in ATtiny5/10, only. Table 6-1. Start-up Times when Using the Internal Calibrated Oscillator Reset Oscillator Configuration Total start-up time 64 ms 6 cycles 21 cycles 64 ms + 6 oscillator cycles + 21 system clock cycles (1) Table 6-2. Start-up Time from Power-Down Sleep Mode. Oscillator start-up time Total start-up time 6 cycles 6 oscillator cycles (1)ATtiny4/5/9/10 [DATASHEET] 21 8127F–AVR–02/2013 6.5 Register Description 6.5.1 CLKMSR – Clock Main Settings Register • Bit 7:2 – Res: Reserved Bits These bits are reserved and always read zero. • Bit 1:0 – CLKMS[1:0]: Clock Main Select Bits These bits select the main clock source of the system. The bits can be written at run-time to switch the source of the main clock. The clock system ensures glitch free switching of the main clock source. The main clock alternatives are shown in Table 6-3. To avoid unintentional switching of main clock source, a protected change sequence must be followed to change the CLKMS bits, as follows: 1. Write the signature for change enable of protected I/O register to register CCP 2. Within four instruction cycles, write the CLKMS bits with the desired value 6.5.2 OSCCAL – Oscillator Calibration Register . • Bits 7:0 – CAL[7:0]: Oscillator Calibration Value The oscillator calibration register is used to trim the calibrated internal oscillator and remove process variations from the oscillator frequency. A pre-programmed calibration value is automatically written to this register during chip reset, giving the factory calibrated frequency as specified in Table 16-2, “Calibration Accuracy of Internal RC Oscillator,” on page 117. The application software can write this register to change the oscillator frequency. The oscillator can be calibrated to frequencies as specified in Table 16-2, “Calibration Accuracy of Internal RC Oscillator,” on page 117. Calibration outside the range given is not guaranteed. The CAL[7:0] bits are used to tune the frequency of the oscillator. A setting of 0x00 gives the lowest frequency, and a setting of 0xFF gives the highest frequency. Bit 7 6 5 4 3 2 1 0 0x37 – – – – – – CLKMS1 CLKMS0 CLKMSR Read/Write R R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 6-3. Selection of Main Clock CLKM1 CLKM0 Main Clock Source 0 0 Calibrated Internal 8 MHzOscillator 0 1 Internal 128 kHz Oscillator (WDT Oscillator) 1 0 External clock 1 1 Reserved Bit 7 6 5 4 3 2 1 0 0x39 CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0 OSCCAL Read/Write R/W R/W R/W R/W R/W R/W R/W R/W Initial Value X X X X X X X XATtiny4/5/9/10 [DATASHEET] 22 8127F–AVR–02/2013 6.5.3 CLKPSR – Clock Prescale Register • Bits 7:4 – Res: Reserved Bits These bits are reserved and will always read as zero. • Bits 3:0 – CLKPS[3:0]: Clock Prescaler Select Bits 3 - 0 These bits define the division factor between the selected clock source and the internal system clock. These bits can be written at run-time to vary the clock frequency and suit the application requirements. As the prescaler divides the master clock input to the MCU, the speed of all synchronous peripherals is reduced accordingly. The division factors are given in Table 6-4. To avoid unintentional changes of clock frequency, a protected change sequence must be followed to change the CLKPS bits: 1. Write the signature for change enable of protected I/O register to register CCP 2. Within four instruction cycles, write the desired value to CLKPS bits At start-up, CLKPS bits are reset to 0b0011 to select the clock division factor of 8. If the selected clock source has a frequency higher than the maximum allowed the application software must make sure a sufficient division factor is used. To make sure the write procedure is not interrupted, interrupts must be disabled when changing prescaler settings. Bit 7 6 5 4 3 2 1 0 0x36 – – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 CLKPSR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 1 1 Table 6-4. Clock Prescaler Select CLKPS3 CLKPS2 CLKPS1 CLKPS0 Clock Division Factor 0000 1 0001 2 0010 4 0 0 1 1 8 (default) 0 1 0 0 16 0 1 0 1 32 0 1 1 0 64 0 1 1 1 128 1 0 0 0 256 1 0 0 1 Reserved 1 0 1 0 Reserved 1 0 1 1 Reserved 1 1 0 0 Reserved 1 1 0 1 Reserved 1 1 1 0 Reserved 1 1 1 1 ReservedATtiny4/5/9/10 [DATASHEET] 23 8127F–AVR–02/2013 7. Power Management and Sleep Modes The high performance and industry leading code efficiency makes the AVR microcontrollers an ideal choise for low power applications. In addition, sleep modes enable the application to shut down unused modules in the MCU, thereby saving power. The AVR provides various sleep modes allowing the user to tailor the power consumption to the application’s requirements. 7.1 Sleep Modes Figure 6-1 on page 17 presents the different clock systems and their distribution in ATtiny4/5/9/10. The figure is helpful in selecting an appropriate sleep mode. Table 7-1 shows the different sleep modes and their wake up sources. Note: 1. The ADC is available in ATtiny5/10, only 2. For INT0, only level interrupt. To enter any of the four sleep modes, the SE bits in SMCR must be written to logic one and a SLEEP instruction must be executed. The SM2:0 bits in the SMCR register select which sleep mode (Idle, ADC Noise Reduction, Standby or Power-down) will be activated by the SLEEP instruction. See Table 7-2 for a summary. If an enabled interrupt occurs while the MCU is in a sleep mode, the MCU wakes up. The MCU is then halted for four cycles in addition to the start-up time, executes the interrupt routine, and resumes execution from the instruction following SLEEP. The contents of the Register File and SRAM are unaltered when the device wakes up from sleep. If a reset occurs during sleep mode, the MCU wakes up and executes from the Reset Vector. Note that if a level triggered interrupt is used for wake-up the changed level must be held for some time to wake up the MCU (and for the MCU to enter the interrupt service routine). See “External Interrupts” on page 36 for details. 7.1.1 Idle Mode When bits SM2:0 are written to 000, the SLEEP instruction makes the MCU enter Idle mode, stopping the CPU but allowing the analog comparator, timer/counter, watchdog, and the interrupt system to continue operating. This sleep mode basically halts clkCPU and clkNVM, while allowing the other clocks to run. Idle mode enables the MCU to wake up from external triggered interrupts as well as internal ones like the timer overflow. If wake-up from the analog comparator interrupt is not required, the analog comparator can be powered down by setting the ACD bit in “ACSR – Analog Comparator Control and Status Register” on page 80. This will reduce power consumption in idle mode. If the ADC is enabled (ATtiny5/10, only), a conversion starts automatically when this mode is entered. Table 7-1. Active Clock Domains and Wake-up Sources in Different Sleep Modes Sleep Mode Active Clock Domains Oscillators Wake-up Sources clkCPU clkNVM clkIO clkADC (1) Main Clock Source Enabled INT0 and Pin Change ADC (1) Other I/O Watchdog Interrupt VLM Interrupt Idle X X X X X X X X ADC Noise Reduction X X X (2) X XX Standby X X (2) X Power-down X (2) XATtiny4/5/9/10 [DATASHEET] 24 8127F–AVR–02/2013 7.1.2 ADC Noise Reduction Mode When bits SM2:0 are written to 001, the SLEEP instruction makes the MCU enter ADC Noise Reduction mode, stopping the CPU but allowing the ADC, the external interrupts, and the watchdog to continue operating (if enabled). This sleep mode halts clkI/O, clkCPU, and clkNVM, while allowing the other clocks to run. This mode improves the noise environment for the ADC, enabling higher resolution measurements. If the ADC is enabled, a conversion starts automatically when this mode is entered. This mode is available in all devices, although only ATtiny5/10 are equipped with an ADC. 7.1.3 Power-down Mode When bits SM2:0 are written to 010, the SLEEP instruction makes the MCU enter Power-down mode. In this mode, the oscillator is stopped, while the external interrupts, and the watchdog continue operating (if enabled). Only a watchdog reset, an external level interrupt on INT0, or a pin change interrupt can wake up the MCU. This sleep mode halts all generated clocks, allowing operation of asynchronous modules only. 7.1.4 Standby Mode When bits SM2:0 are written to 100, the SLEEP instruction makes the MCU enter Standby mode. This mode is identical to Power-down with the exception that the oscillator is kept running. This reduces wake-up time, because the oscillator is already running and doesn't need to be started up. 7.2 Power Reduction Register The Power Reduction Register (PRR), see “PRR – Power Reduction Register” on page 26, provides a method to reduce power consumption by stopping the clock to individual peripherals. When the clock for a peripheral is stopped then: • The current state of the peripheral is frozen. • The associated registers can not be read or written. • Resources used by the peripheral will remain occupied. The peripheral should in most cases be disabled before stopping the clock. Clearing the PRR bit wakes up the peripheral and puts it in the same state as before shutdown. Peripheral shutdown can be used in Idle mode and Active mode to significantly reduce the overall power consumption. See “Supply Current of I/O Modules” on page 121 for examples. In all other sleep modes, the clock is already stopped. 7.3 Minimizing Power Consumption There are several issues to consider when trying to minimize the power consumption in an AVR Core controlled system. In general, sleep modes should be used as much as possible, and the sleep mode should be selected so that as few as possible of the device’s functions are operating. All functions not needed should be disabled. In particular, the following modules may need special consideration when trying to achieve the lowest possible power consumption. 7.3.1 Analog Comparator When entering Idle mode, the analog comparator should be disabled if not used. In the power-down mode, the analog comparator is automatically disabled. See “Analog Comparator” on page 80 for further details.ATtiny4/5/9/10 [DATASHEET] 25 8127F–AVR–02/2013 7.3.2 Analog to Digital Converter If enabled, the ADC will be enabled in all sleep modes. To save power, the ADC should be disabled before entering any sleep mode. When the ADC is turned off and on again, the next conversion will be an extended conversion. See “Analog to Digital Converter” on page 82 for details on ADC operation. The ADC is available in ATtiny5/10, only. 7.3.3 Watchdog Timer If the Watchdog Timer is not needed in the application, this module should be turned off. If the Watchdog Timer is enabled, it will be enabled in all sleep modes, and hence, always consume power. In the deeper sleep modes, this will contribute significantly to the total current consumption. Refer to “Watchdog Timer” on page 30 for details on how to configure the Watchdog Timer. 7.3.4 Port Pins When entering a sleep mode, all port pins should be configured to use minimum power. The most important thing is then to ensure that no pins drive resistive loads. In sleep modes where the I/O clock (clkI/O) is stopped, the input buffers of the device will be disabled. This ensures that no power is consumed by the input logic when not needed. In some cases, the input logic is needed for detecting wake-up conditions, and it will then be enabled. Refer to the section “Digital Input Enable and Sleep Modes” on page 44 for details on which pins are enabled. If the input buffer is enabled and the input signal is left floating or has an analog signal level close to VCC/2, the input buffer will use excessive power. For analog input pins, the digital input buffer should be disabled at all times. An analog signal level close to VCC/2 on an input pin can cause significant current even in active mode. Digital input buffers can be disabled by writing to the Digital Input Disable Register (DIDR0). Refer to “DIDR0 – Digital Input Disable Register 0” on page 81 for details. 7.4 Register Description 7.4.1 SMCR – Sleep Mode Control Register The SMCR Control Register contains control bits for power management. • Bits 7:4 – Res: Reserved Bits These bits are reserved and will always read zero. • Bits 3:1 – SM2..SM0: Sleep Mode Select Bits 2..0 These bits select between available sleep modes, as shown in Table 7-2. Bit 7 6 5 4 3 2 1 0 0x3A – – – – SM2 SM1 SM0 SE SMCR Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0 Table 7-2. Sleep Mode Select SM2 SM1 SM0 Sleep Mode 0 0 0 Idle 0 0 1 ADC noise reduction (1) 0 1 0 Power-down 0 1 1 Reserved 1 0 0 StandbyATtiny4/5/9/10 [DATASHEET] 26 8127F–AVR–02/2013 Note: 1. This mode is available in all devices, although only ATtiny5/10 are equipped with an ADC • Bit 0 – SE: Sleep Enable The SE bit must be written to logic one to make the MCU enter the sleep mode when the SLEEP instruction is executed. To avoid the MCU entering the sleep mode unless it is the programmer’s purpose, it is recommended to write the Sleep Enable (SE) bit to one just before the execution of the SLEEP instruction and to clear it immediately after waking up. 7.4.2 PRR – Power Reduction Register • Bits 7:2 – Res: Reserved Bits These bits are reserved and will always read zero. • Bit 1 – PRADC: Power Reduction ADC Writing a logic one to this bit shuts down the ADC. The ADC must be disabled before shut down. The analog comparator cannot use the ADC input MUX when the ADC is shut down. The ADC is available in ATtiny5/10, only. • Bit 0 – PRTIM0: Power Reduction Timer/Counter0 Writing a logic one to this bit shuts down the Timer/Counter0 module. When the Timer/Counter0 is enabled, operation will continue like before the shutdown. 1 0 1 Reserved 1 1 0 Reserved 1 1 1 Reserved Table 7-2. Sleep Mode Select SM2 SM1 SM0 Sleep Mode Bit 7 6 5 4 3 2 1 0 0x35 – – – – – – PRADC PRTIM0 PRR Read/Write R R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny4/5/9/10 [DATASHEET] 27 8127F–AVR–02/2013 8. System Control and Reset 8.1 Resetting the AVR During reset, all I/O registers are set to their initial values, and the program starts execution from the Reset Vector. The instruction placed at the Reset Vector must be a RJMP – Relative Jump – instruction to the reset handling routine. If the program never enables an interrupt source, the interrupt vectors are not used, and regular program code can be placed at these locations. The circuit diagram in Figure 8-1 shows the reset logic. Electrical parameters of the reset circuitry are defined in section “System and Reset Characteristics” on page 118. Figure 8-1. Reset Logic The I/O ports of the AVR are immediately reset to their initial state when a reset source goes active. This does not require any clock source to be running. After all reset sources have gone inactive, a delay counter is invoked, stretching the internal reset. This allows the power to reach a stable level before normal operation starts. The start up sequence is described in “Starting from Reset” on page 20. 8.2 Reset Sources The ATtiny4/5/9/10 have three sources of reset: • Power-on Reset. The MCU is reset when the supply voltage is below the Power-on Reset threshold (VPOT) • External Reset. The MCU is reset when a low level is present on the RESET pin for longer than the minimum pulse length • Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and the Watchdog is enabled 8.2.1 Power-on Reset A Power-on Reset (POR) pulse is generated by an on-chip detection circuit. The detection level is defined in section “System and Reset Characteristics” on page 118. The POR is activated whenever VCC is below the detection level. The POR circuit can be used to trigger the Start-up Reset, as well as to detect a failure in supply voltage. Reset Flag Register (RSTFLR) CK Delay Counters TIMEOUT WDRF EXTRF PORF DATA BUS Clock Generator SPIKE FILTER Pull-up Resistor Watchdog Oscillator Power-on Reset Circuit VLMATtiny4/5/9/10 [DATASHEET] 28 8127F–AVR–02/2013 A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the Power-on Reset threshold voltage invokes the delay counter, which determines how long the device is kept in reset after VCC rise. The reset signal is activated again, without any delay, when VCC decreases below the detection level. Figure 8-2. MCU Start-up, RESET Tied to VCC Figure 8-3. MCU Start-up, RESET Extended Externally 8.2.2 VCC Level Monitoring ATtiny4/5/9/10 have a VCC Level Monitoring (VLM) circuit that compares the voltage level at the VCC pin against fixed trigger levels. The trigger levels are set with VLM2:0 bits, see “VLMCSR – VCC Level Monitoring Control and Status register” on page 33. The VLM circuit provides a status flag, VLMF, that indicates if voltage on the VCC pin is below the selected trigger level. The flag can be read from VLMCSR, but it is also possible to have an interrupt generated when the VLMF status flag is set. This interrupt is enabled by the VLMIE bit in the VLMCSR register. The flag can be cleared by changing the trigger level or by writing it to zero. The flag is automatically cleared when the voltage at VCC rises back above the selected trigger level. The VLM can also be used to improve reset characteristics at falling supply. Without VLM, the Power-On Reset (POR) does not activate before supply voltage has dropped to a level where the MCU is not necessarily functional any more. With VLM, it is possible to generate a reset earlier. When active, the VLM circuit consumes some power, as illustrated in Figure 17-48 on page 145. To save power the VLM circuit can be turned off completely, or it can be switched on and off at regular intervals. However, detection takes some time and it is therefore recommended to leave the circuitry on long enough for signals to settle. See “VCC Level Monitor” on page 118. V TIME-OUT RESET RESET TOUT INTERNAL t VPOT VRST CC V TIME-OUT TOUT TOUT INTERNAL CC t VPOT VRST > t RESET RESETATtiny4/5/9/10 [DATASHEET] 29 8127F–AVR–02/2013 When VLM is active and voltage at VCC is above the selected trigger level operation will be as normal and the VLM can be shut down for a short period of time. If voltage at VCC drops below the selected threshold the VLM will either flag an interrupt or generate a reset, depending on the configuration. When the VLM has been configured to generate a reset at low supply voltage it will keep the device in reset as long as VCC is below the reset level. See Table 8-4 on page 34 for reset level details. If supply voltage rises above the reset level the condition is removed and the MCU will come out of reset, and initiate the power-up start-up sequence. If supply voltage drops enough to trigger the POR then PORF is set after supply voltage has been restored. 8.2.3 External Reset An External Reset is generated by a low level on the RESET pin if enabled. Reset pulses longer than the minimum pulse width (see section “System and Reset Characteristics” on page 118) will generate a reset, even if the clock is not running. Shorter pulses are not guaranteed to generate a reset. When the applied signal reaches the Reset Threshold Voltage – VRST – on its positive edge, the delay counter starts the MCU after the time-out period – tTOUT – has expired. External reset is ignored during Power-on start-up count. After Power-on reset the internal reset is extended only if RESET pin is low when the initial Power-on delay count is complete. See Figure 8-2 and Figure 8- 3 on page 28. Figure 8-4. External Reset During Operation 8.2.4 Watchdog Reset When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On the falling edge of this pulse, the delay timer starts counting the time-out period tTOUT. See page 30 for details on operation of the Watchdog Timer and Table 16-4 on page 118 for details on reset time-out. CCATtiny4/5/9/10 [DATASHEET] 30 8127F–AVR–02/2013 Figure 8-5. Watchdog Reset During Operation 8.3 Watchdog Timer The Watchdog Timer is clocked from an on-chip oscillator, which runs at 128 kHz. See Figure 8-6. By controlling the Watchdog Timer prescaler, the Watchdog Reset interval can be adjusted as shown in Table 8-2 on page 32. The WDR – Watchdog Reset – instruction resets the Watchdog Timer. The Watchdog Timer is also reset when it is disabled and when a device reset occurs. Ten different clock cycle periods can be selected to determine the reset period. If the reset period expires without another Watchdog Reset, the ATtiny4/5/9/10 resets and executes from the Reset Vector. For timing details on the Watchdog Reset, refer to Table 8-3 on page 33. Figure 8-6. Watchdog Timer The Wathdog Timer can also be configured to generate an interrupt instead of a reset. This can be very helpful when using the Watchdog to wake-up from Power-down. To prevent unintentional disabling of the Watchdog or unintentional change of time-out period, two different safety levels are selected by the fuse WDTON as shown in Table 8-1 on page 31. See “Procedure for Changing the Watchdog Timer Configuration” on page 31 for details. CK CC OSC/2K OSC/4K OSC/8K OSC/16K OSC/32K OSC/64K OSC/128K OSC/256K OSC/512K OSC/1024K MCU RESET WATCHDOG PRESCALER 128 kHz OSCILLATOR WATCHDOG RESET WDP0 WDP1 WDP2 WDP3 WDE MUXATtiny4/5/9/10 [DATASHEET] 31 8127F–AVR–02/2013 8.3.1 Procedure for Changing the Watchdog Timer Configuration The sequence for changing configuration differs between the two safety levels, as follows: 8.3.1.1 Safety Level 1 In this mode, the Watchdog Timer is initially disabled, but can be enabled by writing the WDE bit to one without any restriction. A special sequence is needed when disabling an enabled Watchdog Timer. To disable an enabled Watchdog Timer, the following procedure must be followed: 1. Write the signature for change enable of protected I/O registers to register CCP 2. Within four instruction cycles, in the same operation, write WDE and WDP bits 8.3.1.2 Safety Level 2 In this mode, the Watchdog Timer is always enabled, and the WDE bit will always read as one. A protected change is needed when changing the Watchdog Time-out period. To change the Watchdog Time-out, the following procedure must be followed: 1. Write the signature for change enable of protected I/O registers to register CCP 2. Within four instruction cycles, write the WDP bit. The value written to WDE is irrelevant 8.3.2 Code Examples The following code example shows how to turn off the WDT. The example assumes that interrupts are controlled (e.g., by disabling interrupts globally) so that no interrupts will occur during execution of these functions. Note: See “Code Examples” on page 5. Table 8-1. WDT Configuration as a Function of the Fuse Settings of WDTON WDTON Safety Level WDT Initial State How to Disable the WDT How to Change Time-out Unprogrammed 1 Disabled Protected change sequence No limitations Programmed 2 Enabled Always enabled Protected change sequence Assembly Code Example WDT_off: wdr ; Clear WDRF in RSTFLR in r16, RSTFLR andi r16, ~(1< Table 9-1. Reset and Interrupt Vectors Vector No. Program Address Label Interrupt Source 1 0x0000 RESET External Pin, Power-on Reset, VLM Reset, Watchdog Reset 2 0x0001 INT0 External Interrupt Request 0 3 0x0002 PCINT0 Pin Change Interrupt Request 0 4 0x0003 TIM0_CAPT Timer/Counter0 Input Capture 5 0x0004 TIM0_OVF Timer/Counter0 Overflow 6 0x0005 TIM0_COMPA Timer/Counter0 Compare Match A 7 0x0006 TIM0_COMPB Timer/Counter0 Compare Match B 8 0x0007 ANA_COMP Analog Comparator 9 0x0008 WDT Watchdog Time-out 10 0x0009 VLM VCC Voltage Level Monitor 11 0x000A ADC ADC Conversion Complete (1)ATtiny4/5/9/10 [DATASHEET] 36 8127F–AVR–02/2013 0x000B RESET: ldi r16, high(RAMEND); Main program start 0x000C out SPH,r16 ; Set Stack Pointer 0x000D ldi r16, low(RAMEND) ; to top of RAM 0x000E out SPL,r16 0x000F sei ; Enable interrupts 0x0010 ... ... 9.2 External Interrupts External Interrupts are triggered by the INT0 pin or any of the PCINT3..0 pins. Observe that, if enabled, the interrupts will trigger even if the INT0 or PCINT3..0 pins are configured as outputs. This feature provides a way of generating a software interrupt. Pin change 0 interrupts PCI0 will trigger if any enabled PCINT3..0 pin toggles. The PCMSK Register controls which pins contribute to the pin change interrupts. Pin change interrupts on PCINT3..0 are detected asynchronously, which means that these interrupts can be used for waking the part also from sleep modes other than Idle mode. The INT0 interrupt can be triggered by a falling or rising edge or a low level. This is set up as shown in “EICRA – External Interrupt Control Register A” on page 37. When the INT0 interrupt is enabled and configured as level triggered, the interrupt will trigger as long as the pin is held low. Note that recognition of falling or rising edge interrupts on INT0 requires the presence of an I/O clock, as described in “Clock System” on page 17. 9.2.1 Low Level Interrupt A low level interrupt on INT0 is detected asynchronously. This means that the interrupt source can be used for waking the part also from sleep modes other than Idle (the I/O clock is halted in all sleep modes except Idle). Note that if a level triggered interrupt is used for wake-up from Power-down, the required level must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If the level disappears before the end of the Start-up Time, the MCU will still wake up, but no interrupt will be generated. The start-up time is defined as described in “Clock System” on page 17. If the low level on the interrupt pin is removed before the device has woken up then program execution will not be diverted to the interrupt service routine but continue from the instruction following the SLEEP command. 9.2.2 Pin Change Interrupt Timing A timing example of a pin change interrupt is shown in Figure 9-1.ATtiny4/5/9/10 [DATASHEET] 37 8127F–AVR–02/2013 Figure 9-1. Timing of pin change interrupts 9.3 Register Description 9.3.1 EICRA – External Interrupt Control Register A The External Interrupt Control Register A contains control bits for interrupt sense control. • Bits 7:2 – Res: Reserved Bits These bits are reserved and will always read zero. • Bits 1:0 – ISC01, ISC00: Interrupt Sense Control 0 Bit 1 and Bit 0 The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set. The level and edges on the external INT0 pin that activate the interrupt are defined in Table 9-2. The value on the INT0 pin is sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. If clk PCINT(0) pin_lat pin_sync pcint_in_(0) pcint_syn pcint_setflag PCIF PCINT(0) pin_sync pcint_syn pin_lat D Q LE pcint_setflag PCIF clk clk PCINT(0) in PCMSK(x) pcint_in_(0) 0 x Bit 7 6 5 4 3 2 1 0 0x15 – – – – – – ISC01 ISC00 EICRA Read/Write R R R R R R R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny4/5/9/10 [DATASHEET] 38 8127F–AVR–02/2013 low level interrupt is selected, the low level must be held until the completion of the currently executing instruction to generate an interrupt. 9.3.2 EIMSK – External Interrupt Mask Register • Bits 7:1 – Res: Reserved Bits These bits are reserved and will always read zero. • Bit 0 – INT0: External Interrupt Request 0 Enable When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is enabled. The Interrupt Sense Control bits (ISC01 and ISC00) in the External Interrupt Control Register A (EICRA) define whether the external interrupt is activated on rising and/or falling edge of the INT0 pin or level sensed. Activity on the pin will cause an interrupt request even if INT0 is configured as an output. The corresponding interrupt of External Interrupt Request 0 is executed from the INT0 Interrupt Vector. 9.3.3 EIFR – External Interrupt Flag Register • Bits 7:1 – Res: Reserved Bits These bits are reserved and will always read zero. • Bit 0 – INTF0: External Interrupt Flag 0 When an edge or logic change on the INT0 pin triggers an interrupt request, INTF0 becomes set (one). If the I-bit in SREG and the INT0 bit in EIMSK are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. This flag is constantly zero when INT0 is configured as a level interrupt. Table 9-2. Interrupt 0 Sense Control ISC01 ISC00 Description 0 0 The low level of INT0 generates an interrupt request. 0 1 Any logical change on INT0 generates an interrupt request. 1 0 The falling edge of INT0 generates an interrupt request. 1 1 The rising edge of INT0 generates an interrupt request. Bit 7 6 5 4 3 2 1 0 0x13 – – – – – – – INTO EIMSK Read/Write R R R R R R R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x14 – – – – – – – INTF0 EIFR Read/Write R R R R R R R R/W Initial Value 0 0 0 0 0 0 0 0ATtiny4/5/9/10 [DATASHEET] 39 8127F–AVR–02/2013 9.3.4 PCICR – Pin Change Interrupt Control Register • Bits 7:1 – Res: Reserved Bits These bits are reserved and will always read zero. • Bit 0 – PCIE0: Pin Change Interrupt Enable 0 When the PCIE0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin change interrupt 0 is enabled. Any change on any enabled PCINT3..0 pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI0 Interrupt Vector. PCINT3..0 pins are enabled individually by the PCMSK Register. 9.3.5 PCIFR – Pin Change Interrupt Flag Register • Bits 7:1 – Res: Reserved Bits These bits are reserved and will always read zero. • Bit 0 – PCIF0: Pin Change Interrupt Flag 0 When a logic change on any PCINT3..0 pin triggers an interrupt request, PCIF0 becomes set (one). If the I-bit in SREG and the PCIE0 bit in PCICR are set (one), the MCU will jump to the corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. 9.3.6 PCMSK – Pin Change Mask Register • Bits 7:4 – Res: Reserved Bits These bits are reserved and will always read zero. • Bits 3:0 – PCINT3..0: Pin Change Enable Mask 3..0 Each PCINT3..0 bit selects whether pin change interrupt is enabled on the corresponding I/O pin. If PCINT3..0 is set and the PCIE0 bit in PCICR is set, pin change interrupt is enabled on the corresponding I/O pin. If PCINT3..0 is cleared, pin change interrupt on the corresponding I/O pin is disabled. Bit 7 6 5 4 3 2 1 0 0x12 – – – – – – – PCIE0 PCICR Read/Write R R R R R R R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x11 – – – – – – – PCIF0 PCIFR Read/Write R R R R R R R R/W Initial Value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x10 – – – – PCINT3 PCINT2 PCINT1 PCINT0 PCMSK Read/Write R R R R R/W R/W R/W R/W Initial Value 0 0 0 0 0 0 0 0ATtiny4/5/9/10 [DATASHEET] 40 8127F–AVR–02/2013 10. I/O Ports 10.1 Overview All AVR ports have true Read-Modify-Write functionality when used as general digital I/O ports. This means that the direction of one port pin can be changed without unintentionally changing the direction of any other pin with the SBI and CBI instructions. The same applies when changing drive value (if configured as output) or enabling/disabling of pull-up resistors. Each output buffer has symmetrical drive characteristics with both high sink and source capability. The pin driver is strong enough to drive LED displays directly. All port pins have individually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O pins have protection diodes to both VCC and Ground as indicated in Figure 10-1 on page 40. See “Electrical Characteristics” on page 115 for a complete list of parameters. Figure 10-1. I/O Pin Equivalent Schematic All registers and bit references in this section are written in general form. A lower case “x” represents the numbering letter for the port, and a lower case “n” represents the bit number. However, when using the register or bit defines in a program, the precise form must be used. For example, PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O Registers and bit locations are listed in “Register Description” on page 50. Four I/O memory address locations are allocated for each port, one each for the Data Register – PORTx, Data Direction Register – DDRx, Pull-up Enable Register – PUEx, and the Port Input Pins – PINx. The Port Input Pins I/O location is read only, while the Data Register, the Data Direction Register, and the Pull-up Enable Register are read/write. However, writing a logic one to a bit in the PINx Register, will result in a toggle in the corresponding bit in the Data Register. Using the I/O port as General Digital I/O is described in “Ports as General Digital I/O” on page 41. Most port pins are multiplexed with alternate functions for the peripheral features on the device. How each alternate function interferes with the port pin is described in “Alternate Port Functions” on page 45. Refer to the individual module sections for a full description of the alternate functions. Note that enabling the alternate function of some of the port pins does not affect the use of the other pins in the port as general digital I/O. Cpin Logic Rpu See Figure "General Digital I/O" for Details PxnATtiny4/5/9/10 [DATASHEET] 41 8127F–AVR–02/2013 10.2 Ports as General Digital I/O The ports are bi-directional I/O ports with optional internal pull-ups. Figure 10-2 shows a functional description of one I/O-port pin, here generically called Pxn. Figure 10-2. General Digital I/O(1) Note: 1. WEx, WRx, WPx, WDx, REx, RRx, RPx, and RDx are common to all pins within the same port. clkI/O, and SLEEP are common to all ports. 10.2.1 Configuring the Pin Each port pin consists of four register bits: DDxn, PORTxn, PUExn, and PINxn. As shown in “Register Description” on page 50, the DDxn bits are accessed at the DDRx I/O address, the PORTxn bits at the PORTx I/O address, the PUExn bits at the PUEx I/O address, and the PINxn bits at the PINx I/O address. The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written logic one, Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is configured as an input pin. clk RPx RRx RDx WDx WEx SYNCHRONIZER WDx: WRITE DDRx WRx: WRITE PORTx RRx: READ PORTx REGISTER RPx: READ PORTx PIN clkI/O: I/O CLOCK RDx: READ DDRx WEx: WRITE PUEx REx: READ PUEx D L Q Q REx RESET RESET Q D Q Q Q D CLR PORTxn Q Q D CLR DDxn PINxn DATA BUS SLEEP SLEEP: SLEEP CONTROL Pxn I/O WPx RESET Q Q D CLR PUExn 0 1 WRx WPx: WRITE PINx REGISTERATtiny4/5/9/10 [DATASHEET] 42 8127F–AVR–02/2013 If PORTxn is written logic one when the pin is configured as an output pin, the port pin is driven high (one). If PORTxn is written logic zero when the pin is configured as an output pin, the port pin is driven low (zero). The pull-up resistor is activated, if the PUExn is written logic one. To switch the pull-up resistor off, PUExn has to be written logic zero. Table 10-1 summarizes the control signals for the pin value. Port pins are tri-stated when a reset condition becomes active, even when no clocks are running. 10.2.2 Toggling the Pin Writing a logic one to PINxn toggles the value of PORTxn, independent on the value of DDRxn. Note that the SBI instruction can be used to toggle one single bit in a port. 10.2.3 Break-Before-Make Switching In Break-Before-Make mode, switching the DDRxn bit from input to output introduces an immediate tri-state period lasting one system clock cycle, as indicated in Figure 10-3. For example, if the system clock is 4 MHz and the DDRxn is written to make an output, an immediate tri-state period of 250 ns is introduced before the value of PORTxn is seen on the port pin. To avoid glitches it is recommended that the maximum DDRxn toggle frequency is two system clock cycles. The Break-Before-Make mode applies to the entire port and it is activated by the BBMx bit. For more details, see “PORTCR – Port Control Register” on page 50. When switching the DDRxn bit from output to input no immediate tri-state period is introduced. Table 10-1. Port Pin Configurations DDxn PORTxn PUExn I/O Pull-up Comment 0 X 0 Input No Tri-state (hi-Z) 0 X 1 Input Yes Sources current if pulled low externally 1 0 0 Output No Output low (sink) 1 0 1 Output Yes NOT RECOMMENDED. Output low (sink) and internal pull-up active. Sources current through the internal pull-up resistor and consumes power constantly 1 1 0 Output No Output high (source) 1 1 1 Output Yes Output high (source) and internal pull-up activeATtiny4/5/9/10 [DATASHEET] 43 8127F–AVR–02/2013 Figure 10-3. Switching Between Input and Output in Break-Before-Make-Mode 10.2.4 Reading the Pin Value Independent of the setting of Data Direction bit DDxn, the port pin can be read through the PINxn Register bit. As shown in Figure 10-2 on page 41, the PINxn Register bit and the preceding latch constitute a synchronizer. This is needed to avoid metastability if the physical pin changes value near the edge of the internal clock, but it also introduces a delay. Figure 10-4 shows a timing diagram of the synchronization when reading an externally applied pin value. The maximum and minimum propagation delays are denoted tpd,max and tpd,min respectively. Figure 10-4. Synchronization when Reading an Externally Applied Pin value Consider the clock period starting shortly after the first falling edge of the system clock. The latch is closed when the clock is low, and goes transparent when the clock is high, as indicated by the shaded region of the “SYNC LATCH” signal. The signal value is latched when the system clock goes low. It is clocked into the PINxn Register at the succeeding positive clock edge. As indicated by the two arrows tpd,max and tpd,min, a single signal transition on the pin will be delayed between ½ and 1½ system clock period depending upon the time of assertion. When reading back a software assigned pin value, a nop instruction must be inserted as indicated in Figure 10-5 on page 44. The out instruction sets the “SYNC LATCH” signal at the positive edge of the clock. In this case, the delay tpd through the synchronizer is one system clock period. out DDRx, r16 nop 0x02 0x01 SYSTEM CLK INSTRUCTIONS DDRx intermediate tri-state cycle out DDRx, r17 PORTx 0x55 0x01 intermediate tri-state cycle Px0 Px1 tri-state tri-state tri-state r17 0x01 r16 0x02 XXX in r17, PINx 0x00 0xFF INSTRUCTIONS SYNC LATCH PINxn r17 XXX SYSTEM CLK tpd, max tpd, minATtiny4/5/9/10 [DATASHEET] 44 8127F–AVR–02/2013 Figure 10-5. Synchronization when Reading a Software Assigned Pin Value 10.2.5 Digital Input Enable and Sleep Modes As shown in Figure 10-2 on page 41, the digital input signal can be clamped to ground at the input of the schmitttrigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep Controller in Power-down and Standby modes to avoid high power consumption if some input signals are left floating, or have an analog signal level close to VCC/2. SLEEP is overridden for port pins enabled as external interrupt pins. If the external interrupt request is not enabled, SLEEP is active also for these pins. SLEEP is also overridden by various other alternate functions as described in “Alternate Port Functions” on page 45. If a logic high level (“one”) is present on an asynchronous external interrupt pin configured as “Interrupt on Rising Edge, Falling Edge, or Any Logic Change on Pin” while the external interrupt is not enabled, the corresponding External Interrupt Flag will be set when resuming from the above mentioned Sleep mode, as the clamping in these sleep mode produces the requested logic change. 10.2.6 Unconnected Pins If some pins are unused, it is recommended to ensure that these pins have a defined level. Even though most of the digital inputs are disabled in the deep sleep modes as described above, floating inputs should be avoided to reduce current consumption in all other modes where the digital inputs are enabled (Reset, Active mode and Idle mode). The simplest method to ensure a defined level of an unused pin, is to enable the internal pull-up. In this case, the pull-up will be disabled during reset. If low power consumption during reset is important, it is recommended to use an external pull-up or pulldown. Connecting unused pins directly to VCC or GND is not recommended, since this may cause excessive currents if the pin is accidentally configured as an output. out PORTx, r16 nop in r17, PINx 0xFF 0x00 0xFF SYSTEM CLK r16 INSTRUCTIONS SYNC LATCH PINxn r17 t pdATtiny4/5/9/10 [DATASHEET] 45 8127F–AVR–02/2013 10.2.7 Program Example The following code example shows how to set port B pin 0 high, pin 1 low, and define the port pins from 2 to 3 as input with a pull-up assigned to port pin 2. The resulting pin values are read back again, but as previously discussed, a nop instruction is included to be able to read back the value recently assigned to some of the pins. Note: See “Code Examples” on page 5. 10.3 Alternate Port Functions Most port pins have alternate functions in addition to being general digital I/Os. In Figure 10-6 below is shown how the port pin control signals from the simplified Figure 10-2 on page 41 can be overridden by alternate functions. Assembly Code Example ... ; Define pull-ups and set outputs high ; Define directions for port pins ldi r16,(1<> Cx must be observed for proper operation; a typical load capacitance (Cx) ranges from 5 – 20 pF while Cs is usually about 2 – 50 nF. Increasing amounts of Cx destroy gain, therefore it is important to limit the amount of stray capacitance on both SNS terminals. This can be done, for example, by minimizing trace lengths and widths and keeping these traces away from power or ground traces or copper pours. The traces and any components associated with SNS and SNSK will become touch sensitive and should be treated with caution to limit the touch area to the desired location. A series resistor, Rs, should be placed in line with SNSK to the electrode to suppress ESD and EMC effects. 2.4 Sensitivity 2.4.1 Introduction The sensitivity on the QT1010 is a function of things like the value of Cs, electrode size and capacitance, electrode shape and orientation, the composition and aspect of the object to be sensed, the thickness and composition of any overlaying panel material, and the degree of ground coupling of both sensor and object. 2.4.2 Increasing Sensitivity In some cases it may be desirable to increase sensitivity; for example, when using the sensor with very thick panels having a low dielectric constant, or when the device is used as a proximity sensor. Sensitivity can often be increased by using a larger electrode or reducing panel thickness. Increasing electrode size can have diminishing returns, as high values of Cx will reduce sensor gain. AT42QT1010 [DATASHEET] 6 9541I–AT42–05/2013 The value of Cs also has a dramatic effect on sensitivity, and this can be increased in value with the trade-off of slower response time and more power. Increasing the electrode's surface area will not substantially increase touch sensitivity if its diameter is already much larger in surface area than the object being detected. Panel material can also be changed to one having a higher dielectric constant, which will better help to propagate the field. In the case of proximity detection, usually the object being detected is on an approaching hand, so a larger surface area can be effective. Ground planes around and under the electrode and its SNSK trace will cause high Cx loading and destroy gain. The possible signal-to-noise ratio benefits of ground area are more than negated by the decreased gain from the circuit, and so ground areas around electrodes are discouraged. Metal areas near the electrode will reduce the field strength and increase Cx loading and should be avoided, if possible. Keep ground away from the electrodes and traces. 2.4.3 Decreasing Sensitivity In some cases the QT1010 may be too sensitive. In this case gain can be easily lowered further by decreasing Cs. 2.4.4 Proximity Sensing By increasing the sensitivity, the QT1010 can be used as a very effective proximity sensor, allowing the presence of a nearby object (typically a hand) to be detected. In this scenario, as the object being sensed is typically a hand, very large electrode sizes can be used, which is extremely effective in increasing the sensitivity of the detector. In this case, the value of Cs will also need to be increased to ensure improved sensitivity, as mentioned in Section 2.4.2. Note that, although this affects the responsiveness of the sensor, it is less of an issue in proximity sensing applications; in such applications it is necessary to detect simply the presence of a large object, rather than a small, precise touch.AT42QT1010 [DATASHEET] 7 9541I–AT42–05/2013 3. Operation Specifics 3.1 Run Modes 3.1.1 Introduction The QT1010 has three running modes which depend on the state of the SYNC pin (high or low). 3.1.2 Fast Mode The QT1010 runs in Fast mode if the SYNC pin is permanently high. In this mode the QT1010 runs at maximum speed at the expense of increased current consumption. Fast mode is useful when speed of response is the prime design requirement. The delay between bursts in Fast mode is approximately 1 ms, as shown in Figure 3-1. Figure 3-1. Fast Mode Bursts (SYNC Held High) 3.1.3 Low Power Mode The QT1010 runs in Low Power (LP) mode if the SYNC pin is held low. In this mode it sleeps for approximately 80 ms at the end of each burst, saving power but slowing response. On detecting a possible key touch, it temporarily switches to Fast mode until either the key touch is confirmed or found to be spurious (via the detect integration process). It then returns to LP mode after the key touch is resolved, as shown in Figure 3-2. Figure 3-2. Low Power Mode (SYNC Held Low) SNSK SYNC ~1 ms sleep sleep SYNC SNSK sleep fast detect integrator OUT Key ~80 ms touchAT42QT1010 [DATASHEET] 8 9541I–AT42–05/2013 3.1.4 SYNC Mode It is possible to synchronize the device to an external clock source by placing an appropriate waveform on the SYNC pin. SYNC mode can synchronize multiple QT1010 devices to each other to prevent cross-interference, or it can be used to enhance noise immunity from low frequency sources such as 50Hz or 60Hz mains signals. The SYNC pin is sampled at the end of each burst. If the device is in Fast mode and the SYNC pin is sampled high, then the device continues to operate in Fast mode (Figure 3-1 on page 7). If SYNC is sampled low, then the device goes to sleep. From then on, it will operate in SYNC mode (Figure 3-2). Therefore, to guarantee entry into SYNC mode the low period of the SYNC signal should be longer than the burst length (Figure 3-3). Figure 3-3. SYNC Mode (Triggered by SYNC Edges) However, once SYNC mode has been entered, if the SYNC signal consists of a series of short pulses (>10 µs) then a burst will only occur on the falling edge of each pulse (Figure 3-4) instead of on each change of SYNC signal, as normal (Figure 3-3). In SYNC mode, the device will sleep after each measurement burst (just as in LP mode) but will be awakened by a change in the SYNC signal in either direction, resulting in a new measurement burst. If SYNC remains unchanged for a period longer than the LP mode sleep period (about 80 ms), the device will resume operation in either Fast or LP mode depending on the level of the SYNC pin (Figure 3-3). There is no detect integrator (DI) in SYNC mode (each touch is a detection) but the Max On-duration will depend on the time between SYNC pulses; see Section 3.3 and Section 3.4 on page 9. Recalibration timeout is a fixed number of measurements so will vary with the SYNC period. Figure 3-4. SYNC Mode (Short Pulses) SYNC SYNC SNSK SNSK slow mode sleep period sleep sleep sleep sleep sleep sleep Revert to Fast Mode Revert to Slow Mode slow mode sleep period SNSK SYNC >10 sμ >10 sμ >10 sμAT42QT1010 [DATASHEET] 9 9541I–AT42–05/2013 3.2 Threshold The internal signal threshold level is fixed at 10 counts of change with respect to the internal reference level, which in turn adjusts itself slowly in accordance with the drift compensation mechanism. The QT1010 employs a hysteresis dropout of two counts of the delta between the reference and threshold levels. 3.3 Max On-duration If an object or material obstructs the sense pad the signal may rise enough to create a detection, preventing further operation. To prevent this, the sensor includes a timer which monitors detections. If a detection exceeds the timer setting the sensor performs a full recalibration. This is known as the Max On-duration feature and is set to ~60s (at 3V in LP mode). This will vary slightly with Cs and if SYNC mode is used. As the internal timebase for Max Onduration is determined by the burst rate, the use of SYNC can cause dramatic changes in this parameter depending on the SYNC pulse spacing. For example, at 60Hz SYNC mode the Max On-duration will be ~6s at 3V. 3.4 Detect Integrator It is desirable to suppress detections generated by electrical noise or from quick brushes with an object. To accomplish this, the QT1010 incorporates a detect integration (DI) counter that increments with each detection until a limit is reached, after which the output is activated. If no detection is sensed prior to the final count, the counter is reset immediately to zero. In the QT1010, the required count is four. In LP mode the device will switch to Fast mode temporarily in order to resolve the detection more quickly; after a touch is either confirmed or denied the device will revert back to normal LP mode operation automatically. The DI can also be viewed as a “consensus filter” that requires four successive detections to create an output. 3.5 Forced Sensor Recalibration The QT1010 has no recalibration pin; a forced recalibration is accomplished when the device is powered up or after the recalibration timeout. However, supply drain is low so it is a simple matter to treat the entire IC as a controllable load; driving the QT1010's Vdd pin directly from another logic gate or a microcontroller port will serve as both power and “forced recalibration”. The source resistance of most CMOS gates and microcontrollers is low enough to provide direct power without problem. 3.6 Drift Compensation Signal drift can occur because of changes in Cx and Cs over time. It is crucial that drift be compensated for, otherwise false detections, non-detections, and sensitivity shifts will follow. Drift compensation (Figure 3-5) is performed by making the reference level track the raw signal at a slow rate, but only while there is no detection in effect. The rate of adjustment must be performed slowly, otherwise legitimate detections could be ignored. The QT1010 drift compensates using a slew-rate limited change to the reference level; the threshold and hysteresis values are slaved to this reference. Once an object is sensed, the drift compensation mechanism ceases since the signal is legitimately high, and therefore should not cause the reference level to change.AT42QT1010 [DATASHEET] 10 9541I–AT42–05/2013 Figure 3-5. Drift Compensation The QT1010 drift compensation is asymmetric; the reference level drift-compensates in one direction faster than it does in the other. Specifically, it compensates faster for decreasing signals than for increasing signals. Increasing signals should not be compensated for quickly, since an approaching finger could be compensated for partially or entirely before even approaching the sense electrode. However, an obstruction over the sense pad, for which the sensor has already made full allowance, could suddenly be removed leaving the sensor with an artificially elevated reference level and thus become insensitive to touch. In this latter case, the sensor will compensate for the object's removal very quickly, usually in only a few seconds. With large values of Cs and small values of Cx, drift compensation will appear to operate more slowly than with the converse. Note that the positive and negative drift compensation rates are different. 3.7 Response Time The QT1010's response time is highly dependent on run mode and burst length, which in turn is dependent on Cs and Cx. With increasing Cs, response time slows, while increasing levels of Cx reduce response time. The response time will also be a lot slower in LP or SYNC mode due to a longer time between burst measurements. 3.8 Spread Spectrum The QT1010 modulates its internal oscillator by ±7.5% during the measurement burst. This spreads the generated noise over a wider band, reducing emission levels. This also reduces susceptibility since there is no longer a single fundamental burst frequency. 3.9 Output Features 3.9.1 Output The output of the QT1010 is active-high upon detection. The output will remain active-high for the duration of the detection, or until the Max On-duration expires, whichever occurs first. If a Max On-duration timeout occurs first, the sensor performs a full recalibration and the output becomes inactive (low) until the next detection. 3.9.2 HeartBeat Output The QT1010 output has a HeartBeat “health” indicator superimposed on it in all modes. This operates by taking the output pin into a three-state mode for 15 µs, once before every QT burst. This output state can be used to determine that the sensor is operating properly, using one of several simple methods, or it can be ignored. The HeartBeat indicator can be sampled by using a pull-up resistor on the OUT pin (Figure 3-6), and feeding the resulting positive-going pulse into a counter, flip flop, one-shot, or other circuit. The pulses will only be visible when the chip is not detecting a touch. Threshold Signal Hysteresis Reference OutputAT42QT1010 [DATASHEET] 11 9541I–AT42–05/2013 Figure 3-6. Obtaining HeartBeat Pulses with a Pull-up Resistor (SOT23-6) If the sensor is wired to a microcontroller as shown in Figure 3-7 on page 11, the microcontroller can reconfigure the load resistor to either Vss or Vdd depending on the output state of the QT1010, so that the pulses are evident in either state. Figure 3-7. Using a Microcontroller to Obtain HeartBeat Pulses in Either Output State (SOT23-6) Electromechanical devices like relays will usually ignore the short HeartBeat pulse. The pulse also has too low a duty cycle to visibly affect LEDs. It can be filtered completely if desired, by adding an RC filter to the output, or if interfacing directly and only to a high-impedance CMOS input, by doing nothing or at most adding a small noncritical capacitor from OUT to Vss. 3.9.3 Output Drive The OUT pin is active high and can sink or source up to 2 mA. When a large value of Cs (>20 nF) is used the OUT current should be limited to <1 mA to prevent gain-shifting side effects, which happen when the load current creates voltage drops on the die and bonding wires; these small shifts can materially influence the signal level to cause detection instability. OUT VDD SNSK SNS SYNC/MODE VSS 2 6 4 1 3 5 VDD HeartBeat" Pulse Ro OUT SNSK SNS SYNC/MODE 6 4 1 3 Ro Microcontroller Port_M.x Port_M.yAT42QT1010 [DATASHEET] 12 9541I–AT42–05/2013 4. Circuit Guidelines 4.1 More Information Refer to Application Note QTAN0002, Secrets of a Successful QTouch Design and the Touch Sensors Design Guide (both downloadable from the Atmel website), for more information on construction and design methods. 4.2 Sample Capacitor Cs is the charge sensing sample capacitor. The required Cs value depends on the thickness of the panel and its dielectric constant. Thicker panels require larger values of Cs. Typical values are 2 nF to 50 nF depending on the sensitivity required; larger values of Cs demand higher stability and better dielectric to ensure reliable sensing. The Cs capacitor should be a stable type, such as X7R ceramic or PPS film. For more consistent sensing from unit to unit, 5% tolerance capacitors are recommended. X7R ceramic types can be obtained in 5% tolerance at little or no extra cost. In applications where high sensitivity (long burst length) is required the use of PPS capacitors is recommended. For battery powered operation a higher value sample capacitor is recommended (typical value 8.2 nF). 4.3 UDFN/USON Package Restrictions The central pad on the underside of the UDFN/USON chip is connected to ground. Do not run any tracks underneath the body of the chip, only ground. 4.4 Power Supply and PCB Layout See Section 5.2 on page 14 for the power supply range. At 3 V current drain averages less than 500 µA in Fast mode. If the power supply is shared with another electronic system, care should be taken to ensure that the supply is free of digital spikes, sags, and surges which can adversely affect the QT1010. The QT1010 will track slow changes in Vdd, but it can be badly affected by rapid voltage fluctuations. It is highly recommended that a separate voltage regulator be used just for the QT1010 to isolate it from power supply shifts caused by other components. If desired, the supply can be regulated using a Low Dropout (LDO) regulator, although such regulators often have poor transient line and load stability. See Application Note QTAN0002, Secrets of a Successful QTouch™ Design for further information. Parts placement: The chip should be placed to minimize the SNSK trace length to reduce low frequency pickup, and to reduce stray Cx which degrades gain. The Cs and Rs resistors (see Figure 1-1 on page 4) should be placed as close to the body of the chip as possible so that the trace between Rs and the SNSK pin is very short, thereby reducing the antenna-like ability of this trace to pick up high frequency signals and feed them directly into the chip. A ground plane can be used under the chip and the associated discrete components, but the trace from the Rs resistor and the electrode should not run near ground, to reduce loading. For best EMC performance the circuit should be made entirely with SMT components. Electrode trace routing: Keep the electrode trace (and the electrode itself) away from other signal, power, and ground traces including over or next to ground planes. Adjacent switching signals can induce noise onto the sensing signal; any adjacent trace or ground plane next to, or under, the electrode trace will cause an increase in Cx load and desensitize the device. Note: For proper operation a 100 nF (0.1 µF) ceramic bypass capacitor must be used directly between Vdd and Vss, to prevent latch-up if there are substantial Vdd transients; for example, during an ESD event. The bypass capacitor should be placed very close to the Vss and Vdd pins.AT42QT1010 [DATASHEET] 13 9541I–AT42–05/2013 4.5 Power On On initial power up, the QT1010 requires approximately 100 ms to power on to allow power supplies to stabilize. During this time the OUT pin state is not valid and should be ignored.AT42QT1010 [DATASHEET] 14 9541I–AT42–05/2013 5. Specifications 5.1 Absolute Maximum Specifications 5.2 Recommended Operating Conditions 5.3 AC Specifications Operating temperature –40°C to +85°C Storage temperature –55°C to +125°C VDD 0 to +6.5 V Max continuous pin current, any control or drive pin ±20 mA Short circuit duration to Vss, any pin Infinite Short circuit duration to Vdd, any pin Infinite Voltage forced onto any pin –0.6V to (Vdd + 0.6) V CAUTION: Stresses beyond those listed under Absolute Maximum Specifications may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum specification conditions for extended periods may affect device reliability VDD +1.8 to 5.5 V Short-term supply ripple + noise ±20 mV Long-term supply stability ±100 mV Cs value 2 to 50 nF Cx value 5 to 50 pF Vdd = 3.0 V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted Parameter Description Min Typ Max Units Notes TRC Recalibration time – 200 – ms Cs, Cx dependent TPC Charge duration – 3.05 – µs ±7.5% spread spectrum variation TPT Transfer duration – 9.0 – µs ±7.5% spread spectrum variation TG1 Time between end of burst and start of the next (Fast mode) – 1.2 – ms TG2 Time between end of burst and start of the next (LP mode) – 80 – ms Increases with decreasing VDD See Figure 5-1 on page 15AT42QT1010 [DATASHEET] 15 9541I–AT42–05/2013 Figure 5-1. TG2 – Time Between Bursts (LP Mode) Figure 5-2. TBL – Burst Length TBL Burst length – 2.45 – ms VDD, Cs and Cx dependent. See Section 4.2 for capacitor selection. TR Response time – – 100 ms THB HeartBeat pulse width – 15 – µs Vdd = 3.0 V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted Parameter Description Min Typ Max Units NotesAT42QT1010 [DATASHEET] 16 9541I–AT42–05/2013 5.4 Signal Processing 5.5 DC Specifications Vdd = 3.0V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted Description Min Typ Max Units Notes Threshold differential 10 counts Hysteresis 2 counts Consensus filter length 4 samples Max on-duration 60 seconds (At 3 V in LP mode) Will vary in SYNC mode and with Vdd Vdd = 3.0V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted Parameter Description Min Typ Max Units Notes VDD Supply voltage 1.8 5.5 V IDD Supply current, Fast mode – 203.0 246.0 378.5 542.5 729.0 – µA 1.8 V 2.0 V 3.0 V 4.0 V 5.0 V IDDI Supply current, LP mode – 16.5 19.5 34.0 51.5 73.5 – µA 1.8 V 2.0 V 3.0 V 4.0 V 5.0 V VDDS Supply turn-on slope 10 – – V/s Required for proper start-up VIL Low input logic level – – 0.2 × Vdd 0.3 × Vdd V Vdd = 1.8 V – 2.4 V Vdd = 2.4 V – 5.5 V VHL High input logic level 0.7 × Vdd 0.6 × Vdd – – V Vdd = 1.8 V – 2.4 V Vdd = 2.4 V – 5.5 V VOL Low output voltage – – 0.5 V OUT, 4 mA sink VOH High output voltage 2.3 – – V OUT, 1 mA source IIL Input leakage current – <0.05 1 µA CX Load capacitance range 2 – 50 pF AR Acquisition resolution – 9 14 bitsAT42QT1010 [DATASHEET] 17 9541I–AT42–05/2013 5.6 Mechanical Dimensions 5.6.1 6-pin SOT23-6 9524D–AT42–05/2013 Features  Number of QTouch® Keys:  Up to four  Discrete Outputs:  Four discrete outputs indicating individual key touch  Technology:  Patented spread-spectrum charge-transfer (direct mode)  Electrode Design:  Simple self-capacitance style (refer to the Touch Sensors Design Guide)  Electrode Materials:  Etched copper, silver, carbon, Indium Tin Oxide (ITO)  Electrode Substrates:  PCB, FPCB, plastic films, glass  Panel Materials:  Plastic, glass, composites, painted surfaces (low particle density metallic paints possible)  Panel Thickness:  Up to 10 mm glass, 5 mm plastic (electrode size dependent)  Key Sensitivity:  Fixed key threshold, sensitivity adjusted via sample capacitor value  Adjacent Key Suppression  Patented Adjacent Key Suppression® (AKS®) technology to enable accurate key detection  Interface:  Pin-per-key outputs, plus debug mode to observe sensor signals  Moisture Tolerance:  Increased moisture tolerance based on hardware design and firmware tuning  Signal Processing:  Self-calibration, auto drift compensation, noise filtering  Applications:  Mobile, consumer, white goods, toys, kiosks, POS, and so on  Power:  1.8 V – 5.5 V  Package:  20-pin 3 x 3 mm VQFN RoHS compliant Atmel AT42QT1040 Four-key QTouch® Touch Sensor IC DATASHEETAT42QT1040 [DATASHEET] 2 9524D–AT42–05/2013 1. Pinout and Schematic 1.1 Pinout Configuration NC NC VSS VDD NC SNS2 SNSK1 SNS1 SNSK0 SNS0 OUT0 OUT1 1 2 3 4 5 11 12 13 14 15 20 19 18 17 16 6 7 8 9 10 QT1040 OUT3 OUT2 SNSK3 SNSK2 NC NC NC SNS3AT42QT1040 [DATASHEET] 3 9524D–AT42–05/2013 1.2 Pin Descriptions I/O CMOS input and output OD CMOS open drain output P Ground or power Table 1-1. Pin Listing Pin Name Type Function Notes If Unused... 1 SNS2 I/O Sense pin To Cs2 Leave open 2 SNSK1 I/O Sense pin and option detect To Cs1 and option resistor + key Connect to option resistor* 3 SNS1 I/O Sense pin To Cs1 Leave open 4 SNSK0 I/O Sense pin and option detect To Cs0 and option resistor + key Connect to option resistor* 5 SNS0 I/O Sense pin To Cs0 Leave open 6 N/C – – – 7 N/C – – – 8 Vss P Supply ground – 9 Vdd P Power – 10 N/C – – – 11 OUT0 OD Out 0 Alternative function: Debug CLK Leave open 12 OUT1 OD Out 1 Alternative function: Debug DATA Leave open 13 OUT3 OD Out 3 Leave open 14 OUT2 OD Out 2 Leave open 15 SNSK3 I/O Sense pin To Cs3 + key Leave open 16 SNS3 I/O Sense pin To Cs3 Leave open 17 N/C – – – 18 N/C – – – 19 N/C – – – 20 SNSK2 I/O Sense pin To Cs2 + key Leave open * Option resistor should always be fitted even if channel is unused and Cs capacitor is not fixed.AT42QT1040 [DATASHEET] 4 9524D–AT42–05/2013 1.3 Schematic Figure 1-1. Typical Circuit Suggested regulator manufacturers:  Torex (XC6215 series)  Seiko (S817 series)  BCDSemi (AP2121 series) For component values in Figure 1-1 check the following sections:  Section 3.1 on page 7: Cs capacitors (Cs0 – Cs3)  Section 3.5 on page 7: Voltage levels  Section 3.3 on page 7: LED traces SLOW FAST OFF LED3 LED2 LED1 LED0 VDD VDD 2 1 3 J2 VDD 2 1 3 J1 ON 2 2 5 5 4 4 3 3 1 1 J3 VDD 9 VSS 8 N/C 19 N/C 10 OUT2 14 SNSK3 15 SNSK2 20 SNSK1 2 SNSK0 4 N/C 18 N/C 7 N/C 17 OUT1 12 OUT0 11 SNS3 16 SNS1 3 N/C 6 OUT3 13 SNS0 5 SNS2 1 SPEED SELECT AKS SELECT NOTES: 1) The central pad on the underside of the VQFN chip is a Vss pin and should be connected to ground. Do not put any other tracks underneath the body of the chip. 2) It is important to place all Cs and Rs components physically near to the chip. Add a 100 nF capacitor close to pin 9. QT1040 Creg Creg VREG Follow regulator manufacturer's recommended values for input and output bypass capacitors (Creg). Key0 Key1 Key2 Key3 VUNREG GND Cs0 Cs1 Cs2 Cs3 RL0 RL1 RL2 RL3 RAKS RFS Rs0 Rs1 Rs2 Rs3 Example use of output pinsAT42QT1040 [DATASHEET] 5 9524D–AT42–05/2013 2. Overview of the AT42QT1040 2.1 Introduction The AT42QT1040 (QT1040) is a digital burst mode charge-transfer (QT™) capacitive sensor driver designed for touch-key applications. The device can sense from one to four keys; one to three keys can be disabled by not installing their respective sense capacitors. Any of the four channels can be disabled in this way. The device includes all signal processing functions necessary to provide stable sensing under a wide variety of changing conditions, and the outputs are fully de-bounced. Only a few external parts are required for operation. The QT1040 modulates its bursts in a spread-spectrum fashion in order to heavily suppress the effects of external noise, and to suppress RF emissions. 2.2 Signal Processing 2.2.1 Detect Threshold The internal signal threshold level is fixed at 10 counts of change with respect to the internal reference level. This in turn adjusts itself slowly in accordance with the drift compensation mechanism. See Section 3.1 on page 7 for details on how to adjust the sensitivity of each key. When going out of detect there is a hysteresis element to the detection. The signal threshold must drop below 8 counts of change with respect to the internal reference level to register as un-touched. 2.2.2 Detection Integrator The device features a detection integration mechanism, which acts to confirm a detection in a robust fashion. A perkey counter is incremented each time the key has exceeded its threshold, and a key is only finally declared to be touched when this counter reaches a fixed limit of 5. In other words, the device has to exceed its threshold, and stay there for 5 acquisitions in succession without going below the threshold level, before the key is declared to be touched. 2.2.3 Burst Length Limitations Burst length is the number of times the charge transfer process is performed on a given channel; that is, the number of pulses it takes to measure the key capacitance. The maximum burst length is 2048 pulses. The recommended design is to use a capacitor that gives a signal of <1000 pulses. Longer bursts take more time and use more power. Note that the keys are independent of each other. It is therefore possible, for example, to have a signal of 100 on one key and a signal of 1000 on another. Refer to Application Note QTAN0002, Secrets of a Successful QTouch Design (downloadable from the Atmel website), for more information on using a scope to measure the pulses and hence determine the burst length. Refer also to the Touch Sensors Design Guide. 2.2.4 Adjacent Key Suppression Technology The device includes the Atmel-patented Adjacent Key Suppression (AKS) technology, to allow the use of tightly spaced keys on a keypad with no loss of selectability by the user. There is one global AKS group, implemented so that only one key in the group may be reported as being touched at any one time. The use of AKS is selected by connecting a 1 M resistor between Vdd and the SNSK0 pin (see Section 4.1 on page 9 for more information). When AKS is disabled, any combinations of keys can enter detect.AT42QT1040 [DATASHEET] 6 9524D–AT42–05/2013 2.2.5 Auto Drift Compensation Signal drift can occur because of changes in Cx and Cs over time. It is crucial that drift be compensated for, otherwise false detections, non-detections, and sensitivity shifts will follow. Drift compensation is performed by making the reference level track the raw signal at a slow rate, but only while there is no detection in effect. The rate of adjustment must be performed slowly otherwise legitimate detections could be ignored. Once an object is sensed and a key is in detect, the drift compensation mechanism ceases, since the signal is legitimately high and should not therefore cause the reference level to change. The QT1040 drift compensation is asymmetric, that is, the reference level drift-compensates in one direction faster than it does in the other. Specifically, it compensates faster for decreasing (towards touch) signals than for increasing (away from touch) signals. The reason for this difference in compensation rates is that increasing signals should not be compensated for quickly, since a nearby finger could be compensated for partially or entirely before even approaching the sense electrode. However, decreasing signals need to be compensated for more quickly. For example, an obstruction over the sense pad (for which the sensor has already made full allowance) could suddenly be removed, leaving the sensor with an artificially elevated reference level and thus become insensitive to touch. In this latter case, the sensor will compensate for the object's removal very quickly, usually in only a few seconds. Negative drift (that is, towards touch) occurs at a rate of ~3 seconds, while positive drift occurs at a rate of ~1 second. Drifting only occurs when no keys are in detect state. 2.2.6 Response Time The QT1040 response time is highly dependent on run mode and burst length, which in turn is dependent on Cs and Cx. With increasing Cs, response time slows, while increasing levels of Cx reduce response time. The response time will also be slower in slow mode due to a longer time between burst measurements. This mode offers an increased detection latency in favor of reduced average current consumption. 2.2.7 Spread Spectrum The QT1040 modulates its internal oscillator by ±7.5% during the measurement burst. This spreads the generated noise over a wider band reducing emission levels. This also reduces susceptibility since there is no longer a single fundamental burst frequency. 2.2.8 Max On-duration If an object or material obstructs the sense pad, the signal may rise enough to create a detection, preventing further operation. To prevent this, the sensor includes a timer known as the Max On-duration feature which monitors detections. If a detection exceeds the timer setting, the sensor performs an automatic recalibration. Max On-duration is set to ~30s.AT42QT1040 [DATASHEET] 7 9524D–AT42–05/2013 3. Wiring and Parts 3.1 Cs Sample Capacitors Cs0 – Cs3 are the charge sensing sample capacitors; normally they are identical in nominal value. The optimal Cs values depend on the corresponding keys electrode design, the thickness of the panel and its dielectric constant. Thicker panels require larger values of Cs. Values can be in the range 2.2 nF (for faster operation) to 22 nF (for best sensitivity); typical values are 4.7 nF to 10 nF. The value of Cs should be chosen such that a light touch on a key mounted in a production unit or a prototype panel causes a reliable detection. The chosen Cs value should never be so large that the key signals exceed ~1000, as reported by the chip in the debug data. The Cs capacitors must be X7R or PPS film type, for stability. For consistent sensitivity, they should have a 10% tolerance. Twenty percent tolerance may cause small differences in sensitivity from key to key and unit to unit. If a key is not used, the Cs capacitor may be omitted. 3.2 Rs Resistors The series resistors Rs0 – Rs3 are in line with the electrode connections (close to the QT1040 chip) and are used to limit electrostatic discharge (ESD) currents and to suppress radio frequency (RF) interference. A typical value is 4.7 k, but up to 20 k can be used if it is found to be of benefit. Although these resistors may be omitted, the device may become susceptible to external noise or radio frequency interference (RFI). For details on how to select these resistors refer to Application Note QTAN0002, Secrets of a Successful QTouch Design, and the Touch Sensors Design Guide, both downloadable from the Touch Technology area of the Atmel website, www.atmel.com. 3.3 LED Traces and Other Switching Signals For advice on LEDs and nearby traces, refer to Application Note QTAN0002, Secrets of a Successful QTouch Design, and the Touch Sensors Design Guide, both downloadable from the Touch Technology area of Atmel’s website, www.atmel.com. 3.4 PCB Cleanliness Modern no-clean flux is generally compatible with capacitive sensing circuits. 3.5 Power Supply See Section 5.2 on page 15 for the power supply range. If the power supply fluctuates slowly with temperature, the device tracks and compensates for these changes automatically with only minor changes in sensitivity. If the supply voltage drifts or shifts quickly, the drift compensation mechanism is not able to keep up, causing sensitivity anomalies or false detections. The usual power supply considerations with QT parts apply to the device. The power should be clean and come from a separate regulator if possible. However, this device is designed to minimize the effects of unstable power, and except in extreme conditions should not require a separate Low Dropout (LDO) regulator. CAUTION: If a PCB is reworked to correct soldering faults relating to the device, or to any associated traces or components, be sure that you fully understand the nature of the flux used during the rework process. Leakage currents from hygroscopic ionic residues can stop capacitive sensors from functioning. If you have any doubts, a thorough cleaning after rework may be the only safe option.AT42QT1040 [DATASHEET] 8 9524D–AT42–05/2013 See under Figure 1.3 on page 4 for suggested regulator manufacturers. It is assumed that a larger bypass capacitor (for example, 1 µF) is somewhere else in the power circuit; for example, near the regulator. To assist with transient regulator stability problems, the QT1040 waits 500 µs any time it wakes up from a sleep state (that is, in Sleep mode) before acquiring, to allow Vdd to fully stabilize. 3.6 VQFN Package Restrictions The central pad on the underside of the VQFN chip should be connected to ground. Do not run any tracks underneath the body of the chip, only ground. Figure 3-1 shows an example of good/bad tracking. Figure 3-1. Examples of Good and Bad Tracking Caution: A regulator IC shared with other logic can result in erratic operation and is not advised. A single ceramic 0.1 µF bypass capacitor, with short traces, should be placed very close to the power pins of the IC. Failure to do so can result in device oscillation, high current consumption, erratic operation, and so on. Example of GOOD tracking Example of BAD trackingAT42QT1040 [DATASHEET] 9 9524D–AT42–05/2013 4. Detailed Operations 4.1 Adjacent Key Suppression The use of AKS is selected by the connection of a 1 M resistor (RAKS resistor) between the SNSK0 pin and either Vdd (AKS mode on) or Vss (AKS mode off). Note: Changing the RAKS option will affect the sensitivity of the particular key. Always check that the sensitivity is suitable after a change. Retune Cs0 if necessary. 4.2 Discrete Outputs There are four discrete outputs (channels 0 to 3), located on pins OUT0 to OUT3. An output pin goes active when the corresponding key is touched. The outputs are open-drain type and are active-low. On the OUT2 pin there is a ~500 ns low pulse occurring approximately 20 ms after a power-up/reset (see Figure 4-1 for an example oscilloscope trace of this pulse at two zoom levels). This pulse may need to be considered from the system design perspective. The discrete outputs have sufficient current sinking capability to directly drive LEDs. Try to limit the sink current to less than 5 mA per output and be cautious if connecting LEDs to a power supply other than Vdd; if the LED supply is higher than Vdd it may cause erratic behavior of the QT1040 and back-power the QT1040 through its I/O pins. Table 4-1. RAKS Resistor RAKS Connected To... Mode Vdd AKS on Vss AKS off The RAKS resistor should always be connected to either Vdd or Vss and should not be changed during operation of the device.AT42QT1040 [DATASHEET] 10 9524D–AT42–05/2013 Figure 4-1. ~500 ns Pulse On OUT2 Pin 4.3 Speed Selection Speed selection is determined by a 1 M resistor (RFS resistor) connected between SNSK1 and either Vdd (Fast Mode) or Vss (Slow Mode). In Fast Mode, the device sleeps for 16 ms between burst acquisitions. In Slow Mode, the device sleeps for 64 ms between acquisitions. Hence, Slow Mode conserves more power but results in slightly less responsiveness. Note: The RFS resistor should always be connected to either Vdd or Vss and not changed during operation of the device. Changing the RFS option will affect the sensitivity of the particular key. Always check that the sensitivity is suitable after a change. Retune Cs1 if necessary. 4.4 Moisture Tolerance The presence of water (condensation, sweat, spilt water, and so on) on a sensor can alter the signal values measured and thereby affect the performance of any capacitive device. The moisture tolerance of QTouch devices can be improved by designing the hardware and fine-tuning the firmware following the recommendations in the application note Atmel AVR3002: Moisture Tolerant QTouch Design (www.atmel.com/Images/doc42017.pdf). Pulse on OUT2 SNS0K OUT2 SNS0K OUT2 Power-on/ ~20 ms Reset Table 4-2. RFS Resistor RFS Connected To Mode Vdd Fast mode Vss Slow modeAT42QT1040 [DATASHEET] 11 9524D–AT42–05/2013 4.5 Calibration Calibration is the process by which the sensor chip assesses the background capacitance on each channel. During calibration, a number of samples are taken in quick succession to get a baseline for the channel reference value. Calibration takes place ~50 ms after power is applied to the device. Calibration also occurs if the Max On-duration is exceeded or a positive re-calibration occurs. 4.6 Debug Mode An added feature to this device is a debug option whereby internal parameters from the IC can be clocked out and monitored externally. Debug mode is entered by shorting the CS3 capacitor (SNSK3 and SNS3 pins) on power-up and removing the short within 5 seconds. Note: If the short is not removed within 5 seconds, debug mode is still entered, but with Channel 3 unusable until a re-calibration occurs. Note that as Channel 3 will show as being in detect, a recalibration will occur after Max On-duration (~30 seconds). Debug CLK pin (OUT0) and Debug Data pin (OUT1) float while debug data is not being output and are driven outputs once debug output starts (that is, not open drain). The serial data is clocked out at a rate of ~200 kHz, MSB first, as in Table 4-3. Table 4-3. Serial Data Output Byte Purpose Notes 0 Frame Number Framing index number 0-255 1 Chip Version Upper nibble: major revision Lower nibble: minor revision 2 Reference 0 Low Byte Unsigned 16-bit integer 3 Reference 0 High Byte 4 Reference 1 Low Byte Unsigned 16-bit integer 5 Reference 1 High Byte 6 Reference 2 Low Byte Unsigned 16-bit integer 7 Reference 2 High Byte 8 Reference 3 Low Byte Unsigned 16-bit integer 9 Reference 3 High Byte 10 Signal 0 Low Byte Unsigned 16-bit integer 11 Signal 0 High Byte 12 Signal 1 Low Byte Unsigned 16-bit integer 13 Signal 1 High Byte 14 Signal 2 Low Byte Unsigned 16-bit integer 15 Signal 2 High Byte 16 Signal 3 Low Byte Unsigned 16-bit integer 17 Signal 3 High ByteAT42QT1040 [DATASHEET] 12 9524D–AT42–05/2013 Bit 7: This bit is set during calibration Bits 4 – 6: Contains the number of keys active Bits 0 – 3: Show the touch status of the corresponding keys Figure 4-2 to Figure 4-5 show the usefulness of the debug data out feature. Channels can be monitored and tweaked to the specific application with great accuracy. 18 Delta 0 Low Byte Signed 16-bit integer 19 Delta 0 High Byte 20 Delta 1 Low Byte Signed 16-bit integer 21 Delta 1 High Byte 22 Delta 2 Low Byte Signed 16-bit integer 23 Delta 2 High Byte 24 Delta 3 Low Byte Signed 16-bit integer 25 Delta 3 High Byte 26 Flags Various operational flags 27 Flags2 Unsigned bytes 28 Status Byte Unsigned byte. See Table 4-4 29 Frame Number Repeat of framing index number in byte 0 Table 4-4. Status Byte (Byte 28) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 CAL Number of Keys (2 – 4) Key 3 Key 2 Key 1 Key 0 Table 4-3. Serial Data Output (Continued) Byte Purpose NotesAT42QT1040 [DATASHEET] 13 9524D–AT42–05/2013 Figure 4-2. Byte Clocked Out (~5 µs Period) Figure 4-3. Byte Following Byte (~ 30 µs Period) Figure 4-4. Full Debug Send (30 Bytes)AT42QT1040 [DATASHEET] 14 9524D–AT42–05/2013 Figure 4-5. Debug Lines Floating Between Debug Data Sends (30 Bytes, ~2 ms to Send)AT42QT1040 [DATASHEET] 15 9524D–AT42–05/2013 5. Specifications 5.1 Absolute Maximum Specifications 5.2 Recommended Operating Conditions 5.3 DC Specifications Vdd –0.5 to +6.0 V Max continuous pin current, any control or drive pin ±10 mA Voltage forced onto any pin –0.5 V to (Vdd + 0.5) V Operating temperature –40°C to +85°C Storage temperature –55°C to +125°C Vdd 1.8 V to 5.5 V Supply ripple + noise ±20 mV maximum Cx capacitance per key 2 to 20 pF Vdd = 5.0 V, Cs = 4.7 nF, Ta = recommended range, unless otherwise noted Parameter Description Min Typ Max Units Notes Vil Low input logic level –0.5 – 0.3 V Vih High input logic level 0.6 × Vdd Vdd Vdd + 0.5 V Vol Low output voltage 0 – 0.7 V 10 mA sink current Voh High output voltage 0.8 × Vdd – Vdd V 10 mA source current Iil Input leakage current – <0.05 1 µA Rrst Internal RST pull-up resistor 20 – 50 k CAUTION: Stresses beyond those listed under Absolute Maximum Specifications may cause permanent damage the device. This is a stress rating only and functional operation of the device at these or other conditions beyo those indicated in the operational sections of this specification is not implied. Exposure to absolute maximu specification conditions for extended periods may affect device reliabilityAT42QT1040 [DATASHEET] 16 9524D–AT42–05/2013 5.4 Timing Specifications 5.5 Power Consumption Parameter Description Min Typ Max Units Notes TBS Burst duration – 3.5 – ms Cx = 5 pF, Cs = 18 nF Fc Burst center frequency – 119 – kHz Fm Burst modulation, percentage –7.5 – +7.5 % TPW Burst pulse width – 2 – µs Vdd (V) AKS Mode (RAKS) Speed (RFS) Power Consumption (µA) 1.8 Off Slow 31 Off Fast 104 On Slow 36 On Fast 114 3.3 Off Slow 100 Off Fast 340 On Slow 117 On Fast 380 5.0 Off Slow 215 Off Fast 710 On Slow 245 On Fast 800AT42QT1040 [DATASHEET] 17 9524D–AT42–05/2013 5.6 Mechanical Dimensions Features • High performance, low power AVR® 8-bit Microcontroller • Advanced RISC architecture – 135 powerful instructions – most single clock cycle execution – 32 × 8 general purpose working registers – Fully static operation – Up to 16MIPS throughput at 16MHz – On-chip 2-cycle multiplier • Non-volatile program and data memories – 64/128Kbytes of in-system self-programmable flash • Endurance: 100,000 write/erase cycles – Optional Boot Code section with independent lock bits • USB boot loader programmed by default in the factory • In-system programming by on-chip boot program hardware activated after reset • True read-while-write operation • All supplied parts are pre-programed with a default USB bootloader – 2K/4K (64K/128K flash version) bytes EEPROM • Endurance: 100,000 write/erase cycles – 4K/8K (64K/128K flash version) bytes internal SRAM – Up to 64Kbytes optional external memory space – Programming lock for software security • JTAG (IEEE std. 1149.1 compliant) interface – Boundary-scan capabilities according to the JTAG standard – Extensive on-chip debug support – Programming of flash, EEPROM, fuses, and lock bits through the JTAG interface • USB 2.0 full-speed/low-speed device and on-the-go module – Complies fully with: – Universal serial bus specification REV 2.0 – On-the-go supplement to the USB 2.0 specification rev 1.0 – Supports data transfer rates up to 12Mbit/s and 1.5Mbit/s • USB full-speed/low speed device module with interrupt on transfer completion – Endpoint 0 for control transfers: up to 64-bytes – Six programmable endpoints with in or out directions and with bulk, interrupt or isochronous transfers – Configurable endpoints size up to 256bytes in double bank mode – Fully independent 832bytes USB DPRAM for endpoint memory allocation – Suspend/resume interrupts – Power-on reset and USB bus reset – 48MHz PLL for full-speed bus operation – USB bus disconnection on microcontroller request • USB OTG reduced host: – Supports host negotiation protocol (HNP) and session request protocol (SRP) for OTG dual-role devices – Provide status and control signals for software implementation of HNP and SRP – Provides programmable times required for HNP and SRP • Peripheral features – Two 8-bit timer/counters with separate prescaler and compare mode – Two16-bit timer/counter with separate prescaler, compare- and capture mode 8-bit Atmel Microcontroller with 64/128Kbytes of ISP Flash and USB Controller AT90USB646 AT90USB647 AT90USB1286 AT90USB1287 7593L–AVR–09/122 7593L–AVR–09/12 AT90USB64/128 – Real time counter with separate oscillator – Four 8-bit PWM channels – Six PWM channels with programmable resolution from 2 to 16 bits – Output compare modulator – 8-channels, 10-bit ADC – Programmable serial USART – Master/slave SPI serial interface – Byte oriented 2-wire serial interface – Programmable watchdog timer with separate on-chip oscillator – On-chip analog comparator – Interrupt and wake-up on pin change • Special microcontroller features – Power-on reset and programmable brown-out detection – Internal calibrated oscillator – External and internal interrupt sources – Six sleep modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby • I/O and packages – 48 programmable I/O lines – 64-lead TQFP and 64-lead QFN • Operating voltages – 2.7 - 5.5V • Operating temperature – Industrial (-40°C to +85°C) • Maximum frequency – 8MHz at 2.7V - industrial range – 16MHz at 4.5V - industrial range3 7593L–AVR–09/12 AT90USB64/128 1. Pin configurations Figure 1-1. Pinout Atmel AT90USB64/128-TQFP. AT90USB90128/64 TQFP64 (INT.7/AIN.1/UVcon) PE7 UVcc D- D+ UGnd UCap VBus (IUID) PE3 (SS/PCINT0) PB0 (INT.6/AIN.0) PE6 (PCINT1/SCLK) PB1 (PDI/PCINT2/MOSI) PB2 (PDO/PCINT3/MISO) PB3 (PCINT4/OC.2A) PB4 (PCINT5/OC.1A) PB5 (PCINT6/OC.1B) PB6 (PCINT7/OC.0A/OC.1C) PB7 (INT4/TOSC1) PE4 (INT.5/TOSC2) PE5 RESET VCC GND XTAL2 XTAL1 (OC0B/SCL/INT0) PD0 (OC2B/SDA/INT1) PD1 (RXD1/INT2) PD2 (TXD1/INT3) PD3 (ICP1) PD4 (XCK1) PD5 PA3 (AD3) PA4 (AD4) PA5 (AD5) PA6 (AD6) PA7 (AD7) PE2 (ALE/HWB) PC7 (A15/IC.3/CLKO) PC6 (A14/OC.3A) PC5 (A13/OC.3B) PC4 (A12/OC.3C) PC3 (A11/T.3) PC2 (A10) PC1 (A9) PC0 (A8) PE1 (RD) PE0 (WR) AVCC GND AREF PF0 (ADC0) PF1 (ADC1) PF2 (ADC2) PF3 (ADC3) PF4 (ADC4/TCK) PF5 (ADC5/TMS) PF6 (ADC6/TDO) PF7 (ADC7/TDI) GND VCC PA0 (AD0) PA1 (AD1) PA2 (AD2) (T1) PD6 (T0) PD7 INDEX CORNER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 324 7593L–AVR–09/12 AT90USB64/128 Figure 1-2. Pinout Atmel AT90USB64/128-QFN. Note: The large center pad underneath the MLF packages is made of metal and internally connected to GND. It should be soldered or glued to the board to ensure good mechanical stability. If the center pad is left unconnected, the package might loosen from the board. 2 3 1 4 5 6 7 8 9 10 11 12 13 14 16 33 15 47 46 48 45 44 43 42 41 40 39 38 37 36 35 34 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 AT90USB128/64 (64-lead QFN top view) INDEX CORNER AVCC G N D AREF PF0 (ADC0) PF1 (ADC1) PF2 (ADC2) PF3 (ADC3) PF4 (ADC4/TCK) PF5 (ADC5/TMS) PF6 (ADC6/TDO) PF7 (ADC7/TDI) G N D VCC PA0 (AD0) PA1 (AD1) PA2 (AD2) (INT.7/AIN.1/UVcon) PE7 UVcc D- D+ UGnd UCap VBus (IUID) PE3 (SS/PCINT0) PB0 (INT.6/AIN.0) PE6 (PCINT1/SCLK) PB1 (PDI/PCINT2/MOSI) PB2 (PDO/PCINT3/MISO) PB3 (PCINT4/OC.2A) PB4 (PCINT5/OC.1A) PB5 (PCINT6/OC.1B) PB6 (PCI NT7/OC.0A/OC.1C) PB7 (INT4/TOSC1) PE4 (INT.5/TOSC2) PE5 VCC G N D XTAL2 XTAL1 (OC0B/SCL/I NT0) PD0 (OC2B/SDA/I NT1) PD1 (RXD1/I NT2) PD2 (TXD1/I NT3) PD3 (ICP1) PD4 (XCK1) PD5 (T1) PD6 (T0) PD7 RESET PA3 (AD3) PA4 (AD4) PA5 (AD5) PA6 (AD6) PA7 (AD7) PE2 (ALE/HWB) PC7 (A15/IC.3/CLKO) PC6 (A14/OC.3A) PC5 (A13/OC.3B) PC4 (A12/OC.3C) PC3 (A11/T.3) PC2 (A10) PC1 (A9) PC0 (A8) PE1 (RD) PE0 (WR)5 7593L–AVR–09/12 AT90USB64/128 2. Overview The Atmel® AVR® AT90USB64/128 is a low-power CMOS 8-bit microcontroller based on the Atmel® AVR® enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the AT90USB64/128 achieves throughputs approaching 1MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.6 7593L–AVR–09/12 AT90USB64/128 2.1 Block diagram Figure 2-1. Block diagram. The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting PROGRAM COUNTER ST ACK POINTER PROGRAM FLASH MCU CONTROL REGISTER SRAM GENERAL PURPOSE REGISTERS INSTRUCTION REGISTER TIMER/ COUNTERS INSTRUCTION DECODER DATA DIR. REG. PORTB DATA DIR. REG. PORTE DATA DIR. REG. PORT A DATA DIR. REG. PORTD DATA REGISTER PORTB DATA REGISTER PORTE DATA REGISTER PORT A DATA REGISTER PORTD INTERRUPT UNIT EEPROM USART1 SPI ST ATUS REGISTER Z Y X ALU POR TE DRIVERS POR TB DRIVERS POR TF DRIVERS POR TA DRIVERS POR TD DRIVERS POR TC DRIVERS PE7 - PE0 PB7 - PB0 PF7 - PF0 PA7 - P A0 RESET VCC AGND GND AREF XT AL1 XT AL2 CONTROL LINES + - ANALOG COMP ARATOR PC7 - PC0 INTERNAL OSCILLA TOR WATCHDOG TIMER 8-BIT DA TA BUS AVCC USB TIMING AND CONTROL OSCILLA TOR CALIB. OSC DATA DIR. REG. PORT C DATA REGISTER PORT C ON-CHIP DEBUG JTAG TAP PROGRAMMING LOGIC BOUNDARYSCAN DATA DIR. REG. PORT F DATA REGISTER PORT F ADC POR - BOD RESET PD7 - PD0 TWO-WIRE SERIAL INTERFACE PLL7 7593L–AVR–09/12 AT90USB64/128 architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The Atmel AT90USB64/128 provides the following features: 64/128Kbytes of In-System Programmable Flash with Read-While-Write capabilities, 2K/4Kbytes EEPROM, 4K/8K bytes SRAM, 48 general purpose I/O lines, 32 general purpose working registers, Real Time Counter (RTC), four flexible Timer/Counters with compare modes and PWM, one USART, a byte oriented 2-wire Serial Interface, a 8-channels, 10-bit ADC with optional differential input stage with programmable gain, programmable Watchdog Timer with Internal Oscillator, an SPI serial port, IEEE std. 1149.1 compliant JTAG test interface, also used for accessing the On-chip Debug system and programming and six software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue functioning. The Power-down mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next interrupt or Hardware Reset. In Power-save mode, the asynchronous timer continues to run, allowing the user to maintain a timer base while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules except Asynchronous Timer and ADC, to minimize switching noise during ADC conversions. In Standby mode, the Crystal/Resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low power consumption. In Extended Standby mode, both the main Oscillator and the Asynchronous Timer continue to run. The device is manufactured using the Atmel high-density nonvolatile memory technology. The On-chip ISP Flash allows the program memory to be reprogrammed in-system through an SPI serial interface, by a conventional nonvolatile memory programmer, or by an On-chip Boot program running on the AVR core. The boot program can use any interface to download the application program in the application Flash memory. Software in the Boot Flash section will continue to run while the Application Flash section is updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the AT90USB64/128 is a powerful microcontroller that provides a highly flexible and cost effective solution to many embedded control applications. The AT90USB64/128 AVR is supported with a full suite of program and system development tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit emulators, and evaluation kits.8 7593L–AVR–09/12 AT90USB64/128 2.2 Pin descriptions 2.2.1 VCC Digital supply voltage. 2.2.2 GND Ground. 2.2.3 AVCC Analog supply voltage. 2.2.4 Port A (PA7..PA0) Port A is an 8-bit bidirectional I/O port with internal pull-up resistors (selected for each bit). The Port A output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port A pins that are externally pulled low will source current if the pull-up resistors are activated. The Port A pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port A also serves the functions of various special features of the Atmel AT90USB64/128 as listed on page 78. 2.2.5 Port B (PB7..PB0) Port B is an 8-bit bidirectional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port B has better driving capabilities than the other ports. Port B also serves the functions of various special features of the AT90USB64/128 as listed on page 79. 2.2.6 Port C (PC7..PC0) Port C is an 8-bit bidirectional I/O port with internal pull-up resistors (selected for each bit). The Port C output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port C also serves the functions of special features of the AT90USB64/128 as listed on page 82. 2.2.7 Port D (PD7..PD0) Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port D also serves the functions of various special features of the AT90USB64/128 as listed on page 83. 9 7593L–AVR–09/12 AT90USB64/128 2.2.8 Port E (PE7..PE0) Port E is an 8-bit bidirectional I/O port with internal pull-up resistors (selected for each bit). The Port E output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port E pins that are externally pulled low will source current if the pull-up resistors are activated. The Port E pins are tri-stated when a reset condition becomes active, even if the clock is not running. Port E also serves the functions of various special features of the AT90USB64/128 as listed on page 86. 2.2.9 Port F (PF7..PF0) Port F serves as analog inputs to the A/D Converter. Port F also serves as an 8-bit bidirectional I/O port, if the A/D Converter is not used. Port pins can provide internal pull-up resistors (selected for each bit). The Port F output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port F pins that are externally pulled low will source current if the pull-up resistors are activated. The Port F pins are tri-stated when a reset condition becomes active, even if the clock is not running. If the JTAG interface is enabled, the pull-up resistors on pins PF7(TDI), PF5(TMS), and PF4(TCK) will be activated even if a reset occurs. Port F also serves the functions of the JTAG interface. 2.2.10 DUSB Full speed / Low Speed Negative Data Upstream Port. Should be connected to the USB Dconnector pin with a serial 22Ω resistor. 2.2.11 D+ USB Full speed / Low Speed Positive Data Upstream Port. Should be connected to the USB D+ connector pin with a serial 22Ω resistor. 2.2.12 UGND USB Pads Ground. 2.2.13 UVCC USB Pads Internal Regulator Input supply voltage. 2.2.14 UCAP USB Pads Internal Regulator Output supply voltage. Should be connected to an external capacitor (1µF). 2.2.15 VBUS USB VBUS monitor and OTG negociations. 2.2.16 RESET Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running. The minimum pulse length is given in Table 9-1 on page 58. Shorter pulses are not guaranteed to generate a reset. 2.2.17 XTAL1 Input to the inverting Oscillator amplifier and input to the internal clock operating circuit.10 7593L–AVR–09/12 AT90USB64/128 2.2.18 XTAL2 Output from the inverting oscillator amplifier. 2.2.19 AVCC AVCC is the supply voltage pin for Port F and the A/D Converter. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. 2.2.20 AREF This is the analog reference pin for the A/D Converter. 3. Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. 4. About code examples This documentation contains simple code examples that briefly show how to use various parts of the device. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. These code examples assume that the part specific header file is included before compilation. For I/O registers located in extended I/O map, "IN", "OUT", "SBIS", "SBIC", "CBI", and "SBI" instructions must be replaced with instructions that allow access to extended I/O. Typically "LDS" and "STS" combined with "SBRS", "SBRC", "SBR", and "CBR".11 7593L–AVR–09/12 AT90USB64/128 5. AVR CPU core 5.1 Introduction This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. 5.2 Architectural overview Figure 5-1. Block diagram of the AVR architecture. In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is In-System Re-programmable Flash memory. Flash program memory Instruction register Instruction decoder Program counter Control lines 32 x 8 general purpose registrers ALU Status and control I/O lines EEPROM Data bus 8-bit Data SRAM Direct addressing Indirect addressing Interrupt unit SPI unit Watchdog timer Analog comparator I/O Module 2 I/O Module1 I/O Module n12 7593L–AVR–09/12 AT90USB64/128 The fast-access Register File contains 32 × 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every program memory address contains a 16- or 32-bit instruction. Program Flash memory space is divided in two sections, the Boot Program section and the Application Program section. Both sections have dedicated Lock bits for write and read/write protection. The SPM instruction that writes into the Application Flash memory section must reside in the Boot Program section. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O Memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. In addition, the Atmel AT90USB64/128 has Extended I/O space from 0x60 - 0xFF in SRAM where only the ST/STS/STD and LD/LDS/LDD instructions can be used. 5.3 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See the “Instruction set summary” on page 423 for a detailed description.13 7593L–AVR–09/12 AT90USB64/128 5.4 Status register The status register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the status register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The status register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software. The AVR status register – SREG – is defined as: • Bit 7 – I: Global Interrupt Enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the instruction set reference. • Bit 6 – T: Bit Copy Storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half Carry Flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry Is useful in BCD arithmetic. See the “Instruction set summary” on page 423 for detailed information. • Bit 4 – S: Sign Bit, S = N ⊕ V The S-bit is always an exclusive or between the Negative Flag N and the Two’s Complement Overflow Flag V. See the “Instruction set summary” on page 423 for detailed information. • Bit 3 – V: Two’s Complement Overflow Flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See the “Instruction set summary” on page 423 for detailed information. • Bit 2 – N: Negative Flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See the “Instruction set summary” on page 423 for detailed information. • Bit 1 – Z: Zero Flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the “Instruction set summary” on page 423 for detailed information. Bit 7 6 5 4 3 2 1 0 I T H S V N Z C SREG Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 014 7593L–AVR–09/12 AT90USB64/128 • Bit 0 – C: Carry Flag The Carry Flag C indicates a carry in an arithmetic or logic operation. See the “Instruction set summary” on page 423 for detailed information. 5.5 General purpose register file The register file is optimized for the AVR Enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the register file: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 5-2 shows the structure of the 32 general purpose working registers in the CPU. Figure 5-2. AVR CPU general purpose working registers. Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 5-2, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y-, and Z-pointer registers can be set to index any register in the file. 5.5.1 The X-register, Y-register, and Z-register The registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 5-3. 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E purpose R15 0x0F working R16 0x10 registers R17 0x11 … R26 0x1A X-register Low byte R27 0x1B X-register High byte R28 0x1C Y-register Low byte R29 0x1D Y-register High byte R30 0x1E Z-register Low byte R31 0x1F Z-register High byte15 7593L–AVR–09/12 AT90USB64/128 Figure 5-3. The X-, Y-, and Z-registers. In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the instruction set reference for details). 5.6 Stack pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x0100. The initial value of the stack pointer is the last address of the internal SRAM. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by three when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by three when data is popped from the Stack with return from subroutine RET or return from interrupt RETI. The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. 15 XH XL 0 X-register 7 07 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 07 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 70 7 0 R31 (0x1F) R30 (0x1E) Bit 15 14 13 12 11 10 9 8 SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 SPH SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL 76543210 Read/write R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 1 0 0 0 0 0 1111111116 7593L–AVR–09/12 AT90USB64/128 5.6.1 RAMPZ - Extended Z-pointer register for ELPM/SPM For ELPM/SPM instructions, the Z-pointer is a concatenation of RAMPZ, ZH, and ZL, as shown in Figure 5-4. Note that LPM is not affected by the RAMPZ setting. Figure 5-4. The Z-pointer used by ELPM and SPM. The actual number of bits is implementation dependent. Unused bits in an implementation will always read as zero. For compatibility with future devices, be sure to write these bits to zero. 5.7 Instruction execution timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 5-5 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. Figure 5-5. The parallel instruction fetches and instruction executions. Figure 5-6 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Bit 7 6 5 4 3 2 1 0 RAMPZ7 RAMPZ6 RAMPZ5 RAMPZ4 RAMPZ3 RAMPZ2 RAMPZ1 RAMPZ0 RAMPZ Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit (individually) 7 0 7 0 7 0 RAMPZ ZH ZL Bit (Z-pointer) 23 16 15 8 7 0 clk 1st instruction fetch 1st instruction execute 2nd instruction fetch 2nd instruction execute 3rd instruction fetch 3rd instruction execute 4th instruction fetch T1 T2 T3 T4 CPU17 7593L–AVR–09/12 AT90USB64/128 Figure 5-6. Single cycle ALU operation. 5.8 Reset and interrupt handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate program vector in the program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. Depending on the Program Counter value, interrupts may be automatically disabled when Boot Lock bits BLB02 or BLB12 are programmed. This feature improves software security. See the section “Memory programming” on page 359 for details. The lowest addresses in the program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 68. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. The Interrupt Vectors can be moved to the start of the Boot Flash section by setting the IVSEL bit in the MCU Control Register (MCUCR). Refer to “Interrupts” on page 68 for more information. The Reset Vector can also be moved to the start of the Boot Flash section by programming the BOOTRST Fuse, see “Memory programming” on page 359. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Total execution time Register operands fetch ALU operation execute Result write back T1 T2 T3 T4 clkCPU18 7593L–AVR–09/12 AT90USB64/128 Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence. When using the SEI instruction to enable interrupts, the instruction following SEI will be executed before any pending interrupts, as shown in this example. Assembly code example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMPE ; start EEPROM write sbi EECR, EEPE out SREG, r16 ; restore SREG value (I-bit) C code example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ __disable_interrupt(); EECR |= (1< CSn2:0 > 1). The number of system clock cycles from when the timer is enabled to the first count occurs can be from 1 to N+1 system clock cycles, where N equals the prescaler divisor (8, 64, 256, or 1024). It is possible to use the prescaler reset for synchronizing the Timer/Counter to program execution. However, care must be taken if the other Timer/Counter that shares the same prescaler also uses prescaling. A prescaler reset will affect the prescaler period for all Timer/Counters it is connected to. 13.3 External clock source An external clock source applied to the Tn pin can be used as Timer/Counter clock (clkTn). The Tn pin is sampled once every system clock cycle by the pin synchronization logic. The synchronized (sampled) signal is then passed through the edge detector. Figure 13-1 shows a functional equivalent block diagram of the Tn synchronization and edge detector logic. The registers are clocked at the positive edge of the internal system clock (clkI/O). The latch is transparent in the high period of the internal system clock. The edge detector generates one clkTn pulse for each positive (CSn2:0 = 7) or negative (CSn2:0 = 6) edge it detects. Figure 13-1. Tn/T0 pin sampling. The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles from an edge has been applied to the Tn pin to the counter is updated. Enabling and disabling of the clock input must be done when Tn has been stable for at least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated. Tn_sync (To clock select logic) Synchronization Edge detector D Q D Q LE Tn D Q clkI/O97 7593L–AVR–09/12 AT90USB64/128 Each half period of the external clock applied must be longer than one system clock cycle to ensure correct sampling. The external clock must be guaranteed to have less than half the system clock frequency (fExtClk < fclk_I/O/2) given a 50/50% duty cycle. Since the edge detector uses sampling, the maximum frequency of an external clock it can detect is half the sampling frequency (Nyquist sampling theorem). However, due to variation of the system clock frequency and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is recommended that maximum frequency of an external clock source is less than fclk_I/O/2.5. An external clock source can not be prescaled. Figure 13-2. Prescaler for synchronous Timer/Counters 13.4 GTCCR – General Timer/Counter Control Register • Bit 7 – TSM: Timer/Counter Synchronization Mode Writing the TSM bit to one activates the Timer/Counter Synchronization mode. In this mode, the value that is written to the PSRASY and PSRSYNC bits is kept, hence keeping the corresponding prescaler reset signals asserted. This ensures that the corresponding Timer/Counters are halted and can be configured to the same value without the risk of one of them advancing during configuration. When the TSM bit is written to zero, the PSRASY and PSRSYNC bits are cleared by hardware, and the Timer/Counters start counting simultaneously. • Bit 0 – PSRSYNC: Prescaler Reset for Synchronous Timer/Counters When this bit is one, Timer/Counter0 and Timer/Counter1 and Timer/Counter3 prescaler will be Reset. This bit is normally cleared immediately by hardware, except if the TSM bit is set. Note that Timer/Counter0, Timer/Counter1 and Timer/Counter3 share the same prescaler and a reset of this prescaler will affect all timers. PSR10 Clear Tn Tn clkI/O Synchronization Synchronization TIMER/COUNTERn CLOCK SOURCE clkTn TIMER/COUNTERn CLOCK SOURCE clkTn CSn0 CSn1 CSn2 CSn0 CSn1 CSn2 Bit 7 6 5 4 3 2 1 0 TSM – – – – – PSRASY PSRSYNC GTCCR Read/write R/W R R R R R R/W R/W Initial value 0 0 0 0 0 0 0 098 7593L–AVR–09/12 AT90USB64/128 14. 8-bit Timer/Counter0 with PWM Timer/Counter0 is a general purpose 8-bit Timer/Counter module, with two independent Output Compare Units, and with PWM support. It allows accurate program execution timing (event management) and wave generation. The main features are: • Two independent output compare units • Double buffered output compare registers • Clear timer on compare match (auto reload) • Glitch free, phase correct pulse width modulator (PWM) • Variable PWM period • Frequency generator • Three independent interrupt sources (TOV0, OCF0A, and OCF0B) 14.1 Overview A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 14-1. For the actual placement of I/O pins, refer to “Pinout Atmel AT90USB64/128-TQFP.” on page 3. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “8-bit Timer/Counter register description” on page 108. Figure 14-1. 8-bit Timer/Counter block diagram. 14.1.1 Registers The Timer/Counter (TCNT0) and Output Compare Registers (OCR0A and OCR0B) are 8-bit registers. Interrupt request (abbreviated to Int.Req. in the figure) signals are all visible in the Timer Interrupt Flag Register (TIFR0). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK0). TIFR0 and TIMSK0 are not shown in the figure. The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on the T0 pin. The Clock Select logic block controls which clock source and edge the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the Clock Select logic is referred to as the timer clock (clkT0). Clock select Timer/Counter DATA BUS OCRnA OCRnB = = TCNTn Waveform generation Waveform generation OCnA OCnB = Fixed TOP value Control logic = 0 TOP BOTTOM Count Clear Direction TOVn (int.req.) OCnA (int.req.) OCnB (Int.Req.) TCCRnA TCCRnB Tn Edge detector (From prescaler) clkTn99 7593L–AVR–09/12 AT90USB64/128 The double buffered Output Compare Registers (OCR0A and OCR0B) are compared with the Timer/Counter value at all times. The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pins (OC0A and OC0B). See “Output compare unit” on page 100. for details. The Compare Match event will also set the Compare Flag (OCF0A or OCF0B) which can be used to generate an Output Compare interrupt request. 14.1.2 Definitions Many register and bit references in this section are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 0. A lower case “x” replaces the Output Compare Unit, in this case Compare Unit A or Compare Unit B. However, when using the register or bit defines in a program, the precise form must be used, that is, TCNT0 for accessing Timer/Counter0 counter value and so on. The definitions in the table below are also used extensively throughout the document. 14.2 Timer/Counter clock sources The Timer/Counter can be clocked by an internal or an external clock source. The clock source is selected by the Clock Select logic which is controlled by the Clock Select (CS02:0) bits located in the Timer/Counter Control Register (TCCR0B). For details on clock sources and prescaler, see “Timer/Counter0, Timer/Counter1, and Timer/Counter3 prescalers” on page 96. 14.3 Counter unit The main part of the 8-bit Timer/Counter is the programmable bi-directional counter unit. Figure 14-2 shows a block diagram of the counter and its surroundings. Figure 14-2. Counter unit block diagram. BOTTOM The counter reaches the BOTTOM when it becomes 0x00. MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be the fixed value 0xFF (MAX) or the value stored in the OCR0A Register. The assignment is dependent on the mode of operation. DATA BUS TCNTn Control logic count TOVn (int.req.) Clock select top Tn Edge detector (From prescaler) clkTn bottom direction clear100 7593L–AVR–09/12 AT90USB64/128 Signal description (internal signals): count Increment or decrement TCNT0 by 1. direction Select between increment and decrement. clear Clear TCNT0 (set all bits to zero). clkTn Timer/Counter clock, referred to as clkT0 in the following. top Signalize that TCNT0 has reached maximum value. bottom Signalize that TCNT0 has reached minimum value (zero). Depending of the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT0). clkT0 can be generated from an external or internal clock source, selected by the Clock Select bits (CS02:0). When no clock source is selected (CS02:0 = 0) the timer is stopped. However, the TCNT0 value can be accessed by the CPU, regardless of whether clkT0 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the WGM01 and WGM00 bits located in the Timer/Counter Control Register (TCCR0A) and the WGM02 bit located in the Timer/Counter Control Register B (TCCR0B). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare outputs OC0A and OC0B. For more details about advanced counting sequences and waveform generation, see “Modes of operation” on page 103. The Timer/Counter Overflow Flag (TOV0) is set according to the mode of operation selected by the WGM02:0 bits. TOV0 can be used for generating a CPU interrupt. 14.4 Output compare unit The 8-bit comparator continuously compares TCNT0 with the Output Compare Registers (OCR0A and OCR0B). Whenever TCNT0 equals OCR0A or OCR0B, the comparator signals a match. A match will set the Output Compare Flag (OCF0A or OCF0B) at the next timer clock cycle. If the corresponding interrupt is enabled, the Output Compare Flag generates an Output Compare interrupt. The Output Compare Flag is automatically cleared when the interrupt is executed. Alternatively, the flag can be cleared by software by writing a logical one to its I/O bit location. The Waveform Generator uses the match signal to generate an output according to operating mode set by the WGM02:0 bits and Compare Output mode (COM0x1:0) bits. The maximum and bottom signals are used by the Waveform Generator for handling the special cases of the extreme values in some modes of operation (“Modes of operation” on page 103). Figure 14-3 on page 101 shows a block diagram of the Output Compare unit. 101 7593L–AVR–09/12 AT90USB64/128 Figure 14-3. Output Compare Unit, block diagram. The OCR0x Registers are double buffered when using any of the Pulse Width Modulation (PWM) modes. For the normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR0x Compare Registers to either top or bottom of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR0x Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR0x Buffer Register, and if double buffering is disabled the CPU will access the OCR0x directly. 14.4.1 Force output compare In non-PWM waveform generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC0x) bit. Forcing Compare Match will not set the OCF0x Flag or reload/clear the timer, but the OC0x pin will be updated as if a real Compare Match had occurred (the COM0x1:0 bits settings define whether the OC0x pin is set, cleared or toggled). 14.4.2 Compare match blocking by TCNT0 write All CPU write operations to the TCNT0 Register will block any Compare Match that occur in the next timer clock cycle, even when the timer is stopped. This feature allows OCR0x to be initialized to the same value as TCNT0 without triggering an interrupt when the Timer/Counter clock is enabled. 14.4.3 Using the output compare unit Since writing TCNT0 in any mode of operation will block all Compare Matches for one timer clock cycle, there are risks involved when changing TCNT0 when using the Output Compare Unit, independently of whether the Timer/Counter is running or not. If the value written to TCNT0 equals the OCR0x value, the Compare Match will be missed, resulting in incorrect waveform generation. Similarly, do not write the TCNT0 value equal to BOTTOM when the counter is down-counting. OCFnx (int.req.) = (8-bit comparator) OCRnx OCnx DATA BUS TCNTn WGMn1:0 Waveform generator top FOCn COMnX1:0 bottom102 7593L–AVR–09/12 AT90USB64/128 The setup of the OC0x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC0x value is to use the Force Output Compare (FOC0x) strobe bits in Normal mode. The OC0x Registers keep their values even when changing between Waveform Generation modes. Be aware that the COM0x1:0 bits are not double buffered together with the compare value. Changing the COM0x1:0 bits will take effect immediately. 14.5 Compare Match Output Unit The Compare Output mode (COM0x1:0) bits have two functions. The Waveform Generator uses the COM0x1:0 bits for defining the Output Compare (OC0x) state at the next Compare Match. Also, the COM0x1:0 bits control the OC0x pin output source. Figure 14-4 shows a simplified schematic of the logic affected by the COM0x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM0x1:0 bits are shown. When referring to the OC0x state, the reference is for the internal OC0x Register, not the OC0x pin. If a system reset occur, the OC0x Register is reset to “0”. Figure 14-4. Compare Match Output Unit, schematic. The general I/O port function is overridden by the Output Compare (OC0x) from the Waveform Generator if either of the COM0x1:0 bits are set. However, the OC0x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC0x pin (DDR_OC0x) must be set as output before the OC0x value is visible on the pin. The port override function is independent of the Waveform Generation mode. The design of the Output Compare pin logic allows initialization of the OC0x state before the output is enabled. Note that some COM0x1:0 bit settings are reserved for certain modes of operation. See “8-bit Timer/Counter register description” on page 108. 14.5.1 Compare output mode and waveform generation The Waveform Generator uses the COM0x1:0 bits differently in Normal, CTC, and PWM modes. For all modes, setting the COM0x1:0 = 0 tells the Waveform Generator that no action on the OC0x Register is to be performed on the next Compare Match. For compare output actions in PORT DDR D Q D Q OCnx OCnx Pin D Q Waveform generator COMnx1 COMnx0 0 1 DATA BUS FOCn clkI/O103 7593L–AVR–09/12 AT90USB64/128 the non-PWM modes refer to Table 14-1 on page 109. For fast PWM mode, refer to Table 14-2 on page 109, and for phase correct PWM refer to Table 14-3 on page 109. A change of the COM0x1:0 bits state will have effect at the first Compare Match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC0x strobe bits. 14.6 Modes of operation The mode of operation, that is, the behavior of the Timer/Counter and the Output Compare pins, is defined by the combination of the Waveform Generation mode (WGM02:0) and Compare Output mode (COM0x1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM0x1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM0x1:0 bits control whether the output should be set, cleared, or toggled at a Compare Match (See “Compare Match Output Unit” on page 102.). For detailed timing information see “Timer/Counter timing diagrams” on page 107. 14.6.1 Normal mode The simplest mode of operation is the Normal mode (WGM02:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV0) will be set in the same timer clock cycle as the TCNT0 becomes zero. The TOV0 Flag in this case behaves like a ninth bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV0 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Output Compare Unit can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 14.6.2 Clear Timer on Compare Match (CTC) mode In Clear Timer on Compare or CTC mode (WGM02:0 = 2), the OCR0A Register is used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT0) matches the OCR0A. The OCR0A defines the top value for the counter, hence also its resolution. This mode allows greater control of the Compare Match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 14-5 on page 104. The counter value (TCNT0) increases until a Compare Match occurs between TCNT0 and OCR0A, and then counter (TCNT0) is cleared.104 7593L–AVR–09/12 AT90USB64/128 Figure 14-5. CTC mode, timing diagram. An interrupt can be generated each time the counter value reaches the TOP value by using the OCF0A Flag. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR0A is lower than the current value of TCNT0, the counter will miss the Compare Match. The counter will then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the Compare Match can occur. For generating a waveform output in CTC mode, the OC0A output can be set to toggle its logical level on each Compare Match by setting the Compare Output mode bits to toggle mode (COM0A1:0 = 1). The OC0A value will not be visible on the port pin unless the data direction for the pin is set to output. The waveform generated will have a maximum frequency of fOC0 = fclk_I/O/2 when OCR0A is set to zero (0x00). The waveform frequency is defined by the following equation: The N variable represents the prescale factor (1, 8, 64, 256, or 1024). As for the Normal mode of operation, the TOV0 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x00. 14.6.3 Fast PWM mode The fast Pulse Width Modulation or fast PWM mode (WGM02:0 = 3 or 7) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM option by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. TOP is defined as 0xFF when WGM2:0 = 3, and OCR0A when WGM2:0 = 7. In noninverting Compare Output mode, the Output Compare (OC0x) is cleared on the Compare Match between TCNT0 and OCR0x, and set at BOTTOM. In inverting Compare Output mode, the output is set on Compare Match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct PWM mode that use dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), and therefore reduces total system cost. In fast PWM mode, the counter is incremented until the counter value matches the TOP value. The counter is then cleared at the following timer clock cycle. The timing diagram for the fast TCNTn OCn (Toggle) OCnx Interrupt Flag Set Period 1 2 3 4 (COMnx1:0 = 1) f OCnx f clk_I/O 2 ⋅ ⋅ N ( ) 1 + OCRnx = -------------------------------------------------105 7593L–AVR–09/12 AT90USB64/128 PWM mode is shown in Figure 14-6. The TCNT0 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT0 slopes represent Compare Matches between OCR0x and TCNT0. Figure 14-6. Fast PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOV0) is set each time the counter reaches TOP. If the interrupt is enabled, the interrupt handler routine can be used for updating the compare value. In fast PWM mode, the compare unit allows generation of PWM waveforms on the OC0x pins. Setting the COM0x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM0x1:0 to three: Setting the COM0A1:0 bits to one allows the OC0A pin to toggle on Compare Matches if the WGM02 bit is set. This option is not available for the OC0B pin (see Table 14-2 on page 109). The actual OC0x value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by setting (or clearing) the OC0x Register at the Compare Match between OCR0x and TCNT0, and clearing (or setting) the OC0x Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 64, 256, or 1024). The extreme values for the OCR0A Register represents special cases when generating a PWM waveform output in the fast PWM mode. If the OCR0A is set equal to BOTTOM, the output will be a narrow spike for each MAX+1 timer clock cycle. Setting the OCR0A equal to MAX will result in a constantly high or low output (depending on the polarity of the output set by the COM0A1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC0x to toggle its logical level on each Compare Match (COM0x1:0 = 1). The waveform generated will have a maximum frequency of fOC0 = fclk_I/O/2 when OCR0A is set to zero. This TCNTn OCRnx update and TOVn Interrupt Flag Set Period 1 2 3 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx Interrupt Flag Set 4 5 6 7 f OCnxPWM f clk_I/O N ⋅ 256 = ------------------106 7593L–AVR–09/12 AT90USB64/128 feature is similar to the OC0A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 14.6.4 Phase correct PWM mode The phase correct PWM mode (WGM02:0 = 1 or 5) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is based on a dual-slope operation. The counter counts repeatedly from BOTTOM to TOP and then from TOP to BOTTOM. TOP is defined as 0xFF when WGM2:0 = 1, and OCR0A when WGM2:0 = 5. In noninverting Compare Output mode, the Output Compare (OC0x) is cleared on the Compare Match between TCNT0 and OCR0x while up-counting, and set on the Compare Match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. In phase correct PWM mode the counter is incremented until the counter value matches TOP. When the counter reaches TOP, it changes the count direction. The TCNT0 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 14-7. The TCNT0 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT0 slopes represent Compare Matches between OCR0x and TCNT0. Figure 14-7. Phase correct PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOV0) is set each time the counter reaches BOTTOM. The Interrupt Flag can be used to generate an interrupt each time the counter reaches the BOTTOM value. In phase correct PWM mode, the compare unit allows generation of PWM waveforms on the OC0x pins. Setting the COM0x1:0 bits to two will produce a non-inverted PWM. An inverted PWM output can be generated by setting the COM0x1:0 to three: Setting the COM0A0 bits to TOVn Interrupt Flag Set OCnx Interrupt Flag Set 1 2 3 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx update107 7593L–AVR–09/12 AT90USB64/128 one allows the OC0A pin to toggle on Compare Matches if the WGM02 bit is set. This option is not available for the OC0B pin (see Table 14-3 on page 109). The actual OC0x value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by clearing (or setting) the OC0x Register at the Compare Match between OCR0x and TCNT0 when the counter increments, and setting (or clearing) the OC0x Register at Compare Match between OCR0x and TCNT0 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 64, 256, or 1024). The extreme values for the OCR0A Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR0A is set equal to BOTTOM, the output will be continuously low and if set equal to MAX the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. At the very start of period 2 in Figure 14-7 on page 106 OCnx has a transition from high to low even though there is no Compare Match. The point of this transition is to guarantee symmetry around BOTTOM. There are two cases that give a transition without Compare Match. • OCR0A changes its value from MAX, like in Figure 14-7 on page 106. When the OCR0A value is MAX the OCn pin value is the same as the result of a down-counting Compare Match. To ensure symmetry around BOTTOM the OCn value at MAX must correspond to the result of an up-counting Compare Match • The timer starts counting from a value higher than the one in OCR0A, and for that reason misses the Compare Match and hence the OCn change that would have happened on the way up 14.7 Timer/Counter timing diagrams The Timer/Counter is a synchronous design and the timer clock (clkT0) is therefore shown as a clock enable signal in the following figures. The figures include information on when Interrupt Flags are set. Figure 14-8 contains timing data for basic Timer/Counter operation. The figure shows the count sequence close to the MAX value in all modes other than phase correct PWM mode. Figure 14-8. Timer/Counter timing diagram, no prescaling. Figure 14-9 on page 108 shows the same timing data, but with the prescaler enabled. f OCnxPCPWM f clk_I/O N ⋅ 510 = ------------------ clkTn (clkI/O/1) TOVn clkI/O TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1108 7593L–AVR–09/12 AT90USB64/128 Figure 14-9. Timer/Counter timing diagram, with prescaler (fclk_I/O/8). Figure 14-10 shows the setting of OCF0B in all modes and OCF0A in all modes except CTC mode and PWM mode, where OCR0A is TOP. Figure 14-10. Timer/Counter timing diagram, setting of OCF0x, with prescaler (fclk_I/O/8). Figure 14-11 shows the setting of OCF0A and the clearing of TCNT0 in CTC mode and fast PWM mode where OCR0A is TOP. Figure 14-11. Timer/Counter timing diagram, clear timer on Compare Match mode, with prescaler (fclk_I/O/8) 14.8 8-bit Timer/Counter register description 14.8.1 TCCR0A – Timer/Counter Control Register A TOVn TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn OCRnx Value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn (CTC) TOP TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) Bit 7 6 5 4 3 2 1 0 COM0A1 COM0A0 COM0B1 COM0B0 – – WGM01 WGM00 TCCR0A Read/write R/W R/W R/W R/W R R R/W R/W Initial value 0 0 0 0 0 0 0 0109 7593L–AVR–09/12 AT90USB64/128 • Bits 7:6 – COM01A:0: Compare Match Output A Mode These bits control the Output Compare pin (OC0A) behavior. If one or both of the COM0A1:0 bits are set, the OC0A output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC0A pin must be set in order to enable the output driver. When OC0A is connected to the pin, the function of the COM0A1:0 bits depends on the WGM02:0 bit setting. Table 14-1 shows the COM0A1:0 bit functionality when the WGM02:0 bits are set to a normal or CTC mode (non-PWM). Table 14-2 shows the COM0A1:0 bit functionality when the WGM01:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR0A equals TOP and COM0A1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Fast PWM mode” on page 104 for more details. Table 14-3 shows the COM0A1:0 bit functionality when the WGM02:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR0A equals TOP and COM0A1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 106 for more details. Table 14-1. Compare Output mode, non-PWM mode. COM0A1 COM0A0 Description 0 0 Normal port operation, OC0A disconnected. 0 1 Toggle OC0A on Compare Match 1 0 Clear OC0A on Compare Match 1 1 Set OC0A on Compare Match Table 14-2. Compare Output mode, Fast PWM mode (1). COM0A1 COM0A0 Description 0 0 Normal port operation, OC0A disconnected. 0 1 WGM02 = 0: Normal Port Operation, OC0A Disconnected. WGM02 = 1: Toggle OC0A on Compare Match. 1 0 Clear OC0A on Compare Match, set OC0A at TOP 1 1 Set OC0A on Compare Match, clear OC0A at TOP Table 14-3. Compare Output mode, phase correct PWM mode (1). COM0A1 COM0A0 Description 0 0 Normal port operation, OC0A disconnected. 0 1 WGM02 = 0: Normal Port Operation, OC0A Disconnected. WGM02 = 1: Toggle OC0A on Compare Match. 1 0 Clear OC0A on Compare Match when up-counting. Set OC0A on Compare Match when down-counting. 1 1 Set OC0A on Compare Match when up-counting. Clear OC0A on Compare Match when down-counting.110 7593L–AVR–09/12 AT90USB64/128 • Bits 5:4 – COM0B1:0: Compare Match Output B mode These bits control the Output Compare pin (OC0B) behavior. If one or both of the COM0B1:0 bits are set, the OC0B output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC0B pin must be set in order to enable the output driver. When OC0B is connected to the pin, the function of the COM0B1:0 bits depends on the WGM02:0 bit setting. Table 14-1 shows the COM0A1:0 bit functionality when the WGM02:0 bits are set to a normal or CTC mode (non-PWM). Table 14-2 shows the COM0B1:0 bit functionality when the WGM02:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR0B equals TOP and COM0B1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Fast PWM mode” on page 104 for more details. Table 14-3 shows the COM0B1:0 bit functionality when the WGM02:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR0B equals TOP and COM0B1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 106 for more details. • Bits 3, 2 – Res: Reserved bits These bits are reserved bits in the Atmel AT90USB64/128 and will always read as zero. Table 14-4. Compare Output mode, non-PWM mode. COM01 COM00 Description 0 0 Normal port operation, OC0B disconnected. 0 1 Toggle OC0B on Compare Match 1 0 Clear OC0B on Compare Match 1 1 Set OC0B on Compare Match Table 14-5. Compare Output mode, fast PWM mode (1). COM01 COM00 Description 0 0 Normal port operation, OC0B disconnected. 0 1 Reserved. 1 0 Clear OC0B on Compare Match, set OC0B at TOP. 1 1 Set OC0B on Compare Match, clear OC0B at TOP. Table 14-6. Compare Output mode, phase correct PWM mode (1). COM0A1 COM0A0 Description 0 0 Normal port operation, OC0B disconnected. 0 1 Reserved. 1 0 Clear OC0B on Compare Match when up-counting. Set OC0B on Compare Match when down-counting. 1 1 Set OC0B on Compare Match when up-counting. Clear OC0B on Compare Match when down-counting.111 7593L–AVR–09/12 AT90USB64/128 • Bits 1:0 – WGM01:0: Waveform Generation Mode Combined with the WGM02 bit found in the TCCR0B Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 14-7. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes (see “Modes of operation” on page 103). Notes: 1. MAX = 0xFF 2. BOTTOM = 0x00 14.8.2 TCCR0B – Timer/Counter Control Register B • Bit 7 – FOC0A: Force Output Compare A The FOC0A bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR0B is written when operating in PWM mode. When writing a logical one to the FOC0A bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC0A output is changed according to its COM0A1:0 bits setting. Note that the FOC0A bit is implemented as a strobe. Therefore it is the value present in the COM0A1:0 bits that determines the effect of the forced compare. A FOC0A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR0A as TOP. The FOC0A bit is always read as zero. • Bit 6 – FOC0B: Force Output Compare B The FOC0B bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR0B is written when operating in PWM mode. When writing a logical one to the FOC0B bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC0B output is changed according to its COM0B1:0 bits setting. Note that the FOC0B bit is implemented as a Table 14-7. Waveform Generation Mode bit description. Mode WGM2 WGM1 WGM0 Timer/Counter mode of operation TOP Update of OCRx at TOV flag set on (1)(2) 0 0 0 0 Normal 0xFF Immediate MAX 1 0 0 1 PWM, phase correct 0xFF TOP BOTTOM 2 0 1 0 CTC OCRA Immediate MAX 3 0 1 1 Fast PWM 0xFF TOP MAX 4 1 0 0 Reserved – – – 5 1 0 1 PWM, phase correct OCRA TOP BOTTOM 6 1 1 0 Reserved – – – 7 1 1 1 Fast PWM OCRA TOP TOP Bit 7 6 5 4 3 2 1 0 FOC0A FOC0B – – WGM02 CS02 CS01 CS00 TCCR0B Read/write W W R R R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0112 7593L–AVR–09/12 AT90USB64/128 strobe. Therefore it is the value present in the COM0B1:0 bits that determines the effect of the forced compare. A FOC0B strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR0B as TOP. The FOC0B bit is always read as zero. • Bits 5:4 – Res: Reserved bits These bits are reserved bits and will always read as zero. • Bit 3 – WGM02: Waveform Generation Mode See the description in the “TCCR0A – Timer/Counter Control Register A” on page 108. • Bits 2:0 – CS02:0: Clock Select The three Clock Select bits select the clock source to be used by the Timer/Counter. If external pin modes are used for the Timer/Counter0, transitions on the T0 pin will clock the counter even if the pin is configured as an output. This feature allows software control of the counting. 14.8.3 TCNT0 – Timer/Counter Register The Timer/Counter Register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter. Writing to the TCNT0 Register blocks (removes) the Compare Match on the following timer clock. Modifying the counter (TCNT0) while the counter is running, introduces a risk of missing a Compare Match between TCNT0 and the OCR0x Registers. 14.8.4 OCR0A – Output Compare Register A Table 14-8. Clock Select bit description. CS02 CS01 CS00 Description 0 0 0 No clock source (Timer/Counter stopped) 0 0 1 clkI/O/(No prescaling) 0 1 0 clkI/O/8 (From prescaler) 0 1 1 clkI/O/64 (From prescaler) 1 0 0 clkI/O/256 (From prescaler) 1 0 1 clkI/O/1024 (From prescaler) 1 1 0 External clock source on T0 pin. Clock on falling edge. 1 1 1 External clock source on T0 pin. Clock on rising edge. Bit 7 6 5 4 3 2 1 0 TCNT0[7:0] TCNT0 Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR0A[7:0] OCR0A Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0113 7593L–AVR–09/12 AT90USB64/128 The Output Compare Register A contains an 8-bit value that is continuously compared with the counter value (TCNT0). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC0A pin. 14.8.5 OCR0B – Output Compare Register B The Output Compare Register B contains an 8-bit value that is continuously compared with the counter value (TCNT0). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC0B pin. 14.8.6 TIMSK0 – Timer/Counter Interrupt Mask Register • Bits 7..3, 0 – Res: Reserved bits These bits are reserved bits and will always read as zero. • Bit 2 – OCIE0B: Timer/Counter Output Compare Match B Interrupt Enable When the OCIE0B bit is written to one, and the I-bit in the Status Register is set, the Timer/Counter Compare Match B interrupt is enabled. The corresponding interrupt is executed if a Compare Match in Timer/Counter occurs, that is, when the OCF0B bit is set in the Timer/Counter Interrupt Flag Register – TIFR0. • Bit 1 – OCIE0A: Timer/Counter0 Output Compare Match A Interrupt Enable When the OCIE0A bit is written to one, and the I-bit in the Status Register is set, the Timer/Counter0 Compare Match A interrupt is enabled. The corresponding interrupt is executed if a Compare Match in Timer/Counter0 occurs, that is, when the OCF0A bit is set in the Timer/Counter 0 Interrupt Flag Register – TIFR0. • Bit 0 – TOIE0: Timer/Counter0 Overflow Interrupt Enable When the TOIE0 bit is written to one, and the I-bit in the Status Register is set, the Timer/Counter0 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter0 occurs, that is, when the TOV0 bit is set in the Timer/Counter 0 Interrupt Flag Register – TIFR0. 14.8.7 TIFR0 – Timer/Counter 0 Interrupt Flag Register • Bits 7..3, 0 – Res: Reserved bits These bits are reserved bits in the Atmel AT90USB64/128 and will always read as zero. Bit 7 6 5 4 3 2 1 0 OCR0B[7:0] OCR0B Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – – – – OCIE0B OCIE0A TOIE0 TIMSK0 Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – – – – OCF0B OCF0A TOV0 TIFR0 Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0114 7593L–AVR–09/12 AT90USB64/128 • Bit 2 – OCF0B: Timer/Counter 0 Output Compare B Match Flag The OCF0B bit is set when a Compare Match occurs between the Timer/Counter and the data in OCR0B – Output Compare Register0 B. OCF0B is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF0B is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE0B (Timer/Counter Compare B Match Interrupt Enable), and OCF0B are set, the Timer/Counter Compare Match Interrupt is executed. • Bit 1 – OCF0A: Timer/Counter 0 Output Compare A Match Flag The OCF0A bit is set when a Compare Match occurs between the Timer/Counter0 and the data in OCR0A – Output Compare Register0. OCF0A is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF0A is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE0A (Timer/Counter0 Compare Match Interrupt Enable), and OCF0A are set, the Timer/Counter0 Compare Match Interrupt is executed. • Bit 0 – TOV0: Timer/Counter0 Overflow Flag The bit TOV0 is set when an overflow occurs in Timer/Counter0. TOV0 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV0 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE0 (Timer/Counter0 Overflow Interrupt Enable), and TOV0 are set, the Timer/Counter0 Overflow interrupt is executed. The setting of this flag is dependent of the WGM02:0 bit setting. Refer to Table 14-7, “Waveform Generation Mode bit description.” on page 111.115 7593L–AVR–09/12 AT90USB64/128 15. 16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3) The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave generation, and signal timing measurement. The main features are: • True 16-bit design (that is, allows 16-bit PWM) • Three independent output compare units • Double buffered output compare registers • One input capture unit • Input capture noise canceler • Clear timer on compare match (auto reload) • Glitch-free, phase correct pulse width modulator (PWM) • Variable PWM period • Frequency generator • External event counter • Ten independent interrupt sources (TOV1, OCF1A, OCF1B, OCF1C, ICF1, TOV3, OCF3A, OCF3B, OCF3C, and ICF3) 15.1 Overview Most register and bit references in this section are written in general form. A lower case “n” replaces the Timer/Counter number, and a lower case “x” replaces the Output Compare unit channel. However, when using the register or bit defines in a program, the precise form must be used, that is, TCNT1 for accessing Timer/Counter1 counter value and so on. A simplified block diagram of the 16-bit Timer/Counter is shown in Figure 15-1 on page 116. For the actual placement of I/O pins, see “Pinout Atmel AT90USB64/128-TQFP.” on page 3. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3)” on page 115. The Power Reduction Timer/Counter1 bit, PRTIM1, in “PRR0 – Power Reduction Register 0” on page 54 must be written to zero to enable Timer/Counter1 module. The Power Reduction Timer/Counter3 bit, PRTIM3, in “PRR1 – Power Reduction Register 1” on page 55 must be written to zero to enable Timer/Counter3 module.116 7593L–AVR–09/12 AT90USB64/128 Figure 15-1. 16-bit Timer/Counter block diagram (1). Note: 1. Refer to Figure 1-1 on page 3, Table 11-6 on page 79, and Table 11-9 on page 82 for Timer/Counter1 and 3 and 3 pin placement and description. 15.1.1 Registers The Timer/Counter (TCNTn), Output Compare Registers (OCRnA/B/C), and Input Capture Register (ICRn) are all 16-bit registers. Special procedures must be followed when accessing the 16- bit registers. These procedures are described in the section “Accessing 16-bit registers” on page 117. The Timer/Counter Control Registers (TCCRnA/B/C) are 8-bit registers and have no CPU access restrictions. Interrupt requests (shorten as Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFRn). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSKn). TIFRn and TIMSKn are not shown in the figure since these registers are shared by other timer units. The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on the Tn pin. The Clock Select logic block controls which clock source and edge the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the clock select logic is referred to as the timer clock (clkTn). The double buffered Output Compare Registers (OCRnA/B/C) are compared with the Timer/Counter value at all time. The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pin (OCnA/B/C). ICFn (Int.Req.) TOVn (int.req.) Clock select Timer/Counter DATABUS ICRn = = = TCNTn Waveform generation Waveform generation Waveform generation OCnA OCnB OCnC Noise canceler ICPn = Fixed TOP values Edge detector Control logic = 0 TOP BOTTOM Count Clear Direction OCFnA (Int.Req.) OCFnB (Int.Req.) OCFnC (Int.Req.) TCCRnA TCCRnB TCCRnC ( From Analog Comparator Ouput ) Tn Edge detector (From prescaler) TCLK OCRnC OCRnB OCRnA117 7593L–AVR–09/12 AT90USB64/128 See “Output Compare units” on page 124.. The compare match event will also set the Compare Match Flag (OCFnA/B/C) which can be used to generate an Output Compare interrupt request. The Input Capture Register can capture the Timer/Counter value at a given external (edge triggered) event on either the Input Capture pin (ICPn) or on the Analog Comparator pins (see “Analog Comparator” on page 304) The Input Capture unit includes a digital filtering unit (Noise Canceler) for reducing the chance of capturing noise spikes. The TOP value, or maximum Timer/Counter value, can in some modes of operation be defined by either the OCRnA Register, the ICRn Register, or by a set of fixed values. When using OCRnA as TOP value in a PWM mode, the OCRnA Register can not be used for generating a PWM output. However, the TOP value will in this case be double buffered allowing the TOP value to be changed in run time. If a fixed TOP value is required, the ICRn Register can be used as an alternative, freeing the OCRnA to be used as PWM output. 15.1.2 Definitions The following definitions are used extensively throughout the document: 15.2 Accessing 16-bit registers The TCNTn, OCRnA/B/C, and ICRn are 16-bit registers that can be accessed by the AVR CPU via the 8-bit data bus. The 16-bit register must be byte accessed using two read or write operations. Each 16-bit timer has a single 8-bit register for temporary storing of the high byte of the 16- bit access. The same Temporary Register is shared between all 16-bit registers within each 16- bit timer. Accessing the low byte triggers the 16-bit read or write operation. When the low byte of a 16-bit register is written by the CPU, the high byte stored in the Temporary Register, and the low byte written are both copied into the 16-bit register in the same clock cycle. When the low byte of a 16-bit register is read by the CPU, the high byte of the 16-bit register is copied into the Temporary Register in the same clock cycle as the low byte is read. Not all 16-bit accesses uses the Temporary Register for the high byte. Reading the OCRnA/B/C 16-bit registers does not involve using the Temporary Register. To do a 16-bit write, the high byte must be written before the low byte. For a 16-bit read, the low byte must be read before the high byte. The following code examples show how to access the 16-bit timer registers assuming that no interrupts updates the temporary register. The same principle can be used directly for accessing the OCRnA/B/C and ICRn Registers. Note that when using “C”, the compiler handles the 16-bit access. BOTTOM The counter reaches the BOTTOM when it becomes 0x0000. MAX The counter reaches its MAXimum when it becomes 0xFFFF (decimal 65535). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be one of the fixed values: 0x00FF, 0x01FF, or 0x03FF, or to the value stored in the OCRnA or ICRn Register. The assignment is dependent of the mode of operation.118 7593L–AVR–09/12 AT90USB64/128 Note: 1. See “About code examples” on page 10. The assembly code example returns the TCNTn value in the r17:r16 register pair. It is important to notice that accessing 16-bit registers are atomic operations. If an interrupt occurs between the two instructions accessing the 16-bit register, and the interrupt code updates the temporary register by accessing the same or any other of the 16-bit Timer Registers, then the result of the access outside the interrupt will be corrupted. Therefore, when both the main code and the interrupt code update the temporary register, the main code must disable the interrupts during the 16-bit access. Assembly code examples (1) ... ; Set TCNTn to 0x01FF ldi r17,0x01 ldi r16,0xFF out TCNTnH,r17 out TCNTnL,r16 ; Read TCNTn into r17:r16 in r16,TCNTnL in r17,TCNTnH ... C code examples (1) unsigned int i; ... /* Set TCNTn to 0x01FF */ TCNTn = 0x1FF; /* Read TCNTn into i */ i = TCNTn; ...119 7593L–AVR–09/12 AT90USB64/128 The following code examples show how to do an atomic read of the TCNTn Register contents. Reading any of the OCRnA/B/C or ICRn Registers can be done by using the same principle. Note: 1. See “About code examples” on page 10. The assembly code example returns the TCNTn value in the r17:r16 register pair. Assembly code example (1) TIM16_ReadTCNTn: ; Save global interrupt flag in r18,SREG ; Disable interrupts cli ; Read TCNTn into r17:r16 in r16,TCNTnL in r17,TCNTnH ; Restore global interrupt flag out SREG,r18 ret C code example (1) unsigned int TIM16_ReadTCNTn( void ) { unsigned char sreg; unsigned int i; /* Save global interrupt flag */ sreg = SREG; /* Disable interrupts */ __disable_interrupt(); /* Read TCNTn into i */ i = TCNTn; /* Restore global interrupt flag */ SREG = sreg; return i; }120 7593L–AVR–09/12 AT90USB64/128 The following code examples show how to do an atomic write of the TCNTn Register contents. Writing any of the OCRnA/B/C or ICRn Registers can be done by using the same principle. Note: 1. See “About code examples” on page 10. The assembly code example requires that the r17:r16 register pair contains the value to be written to TCNTn. 15.2.1 Reusing the Temporary High Byte register If writing to more than one 16-bit register where the high byte is the same for all registers written, then the high byte only needs to be written once. However, note that the same rule of atomic operation described previously also applies in this case. 15.3 Timer/Counter clock sources The Timer/Counter can be clocked by an internal or an external clock source. The clock source is selected by the Clock Select logic which is controlled by the Clock Select (CSn2:0) bits located in the Timer/Counter control Register B (TCCRnB). For details on clock sources and prescaler, see Section “Timer/Counter0, Timer/Counter1, and Timer/Counter3 prescalers” on page 96. Assembly code example (1) TIM16_WriteTCNTn: ; Save global interrupt flag in r18,SREG ; Disable interrupts cli ; Set TCNTn to r17:r16 out TCNTnH,r17 out TCNTnL,r16 ; Restore global interrupt flag out SREG,r18 ret C code example (1) void TIM16_WriteTCNTn( unsigned int i ) { unsigned char sreg; unsigned int i; /* Save global interrupt flag */ sreg = SREG; /* Disable interrupts */ __disable_interrupt(); /* Set TCNTn to i */ TCNTn = i; /* Restore global interrupt flag */ SREG = sreg; }121 7593L–AVR–09/12 AT90USB64/128 15.4 Counter unit The main part of the 16-bit Timer/Counter is the programmable 16-bit bi-directional counter unit. Figure 15-2 shows a block diagram of the counter and its surroundings. Figure 15-2. Counter unit block diagram. Signal description (internal signals): Count Increment or decrement TCNTn by 1. Direction Select between increment and decrement. Clear Clear TCNTn (set all bits to zero). clkTn Timer/Counter clock. TOP Signalize that TCNTn has reached maximum value. BOTTOM Signalize that TCNTn has reached minimum value (zero). The 16-bit counter is mapped into two 8-bit I/O memory locations: Counter High (TCNTnH) containing the upper eight bits of the counter, and Counter Low (TCNTnL) containing the lower eight bits. The TCNTnH Register can only be indirectly accessed by the CPU. When the CPU does an access to the TCNTnH I/O location, the CPU accesses the high byte temporary register (TEMP). The temporary register is updated with the TCNTnH value when the TCNTnL is read, and TCNTnH is updated with the temporary register value when TCNTnL is written. This allows the CPU to read or write the entire 16-bit counter value within one clock cycle via the 8-bit data bus. It is important to notice that there are special cases of writing to the TCNTn Register when the counter is counting that will give unpredictable results. The special cases are described in the sections where they are of importance. Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkTn). The clkTn can be generated from an external or internal clock source, selected by the Clock Select bits (CSn2:0). When no clock source is selected (CSn2:0 = 0) the timer is stopped. However, the TCNTn value can be accessed by the CPU, independent of whether clkTn is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the Waveform Generation mode bits (WGMn3:0) located in the Timer/Counter Control Registers A and B (TCCRnA and TCCRnB). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare outputs OCnx. For more details about advanced counting sequences and waveform generation, see Section “Modes of operation” on page 127. TEMP (8-bit) DATA BUS (8-bit) TCNTn (16-bit counter) TCNTnH (8-bit) TCNTnL (8-bit) Control logic Count Clear Direction TOVn (Int.Req.) Clock select TOP BOTTOM Tn Edge detector (From prescaler) clkTn122 7593L–AVR–09/12 AT90USB64/128 The Timer/Counter Overflow Flag (TOVn) is set according to the mode of operation selected by the WGMn3:0 bits. TOVn can be used for generating a CPU interrupt. 15.5 Input Capture unit The Timer/Counter incorporates an Input Capture unit that can capture external events and give them a time-stamp indicating time of occurrence. The external signal indicating an event, or multiple events, can be applied via the ICPn pin or alternatively, for the Timer/Counter1 only, via the Analog Comparator unit. The time-stamps can then be used to calculate frequency, duty-cycle, and other features of the signal applied. Alternatively the time-stamps can be used for creating a log of the events. The Input Capture unit is illustrated by the block diagram shown in Figure 15-3. The elements of the block diagram that are not directly a part of the input capture unit are gray shaded. The small “n” in register and bit names indicates the Timer/Counter number. Figure 15-3. Input Capture Unit block diagram. Note: The Analog Comparator Output (ACO) can only trigger the Timer/Counter1 ICP – not Timer/Counter3, 4, or 5. When a change of the logic level (an event) occurs on the Input Capture Pin (ICPn), alternatively on the analog Comparator output (ACO), and this change confirms to the setting of the edge detector, a capture will be triggered. When a capture is triggered, the 16-bit value of the counter (TCNTn) is written to the Input Capture Register (ICRn). The Input Capture Flag (ICFn) is set at the same system clock as the TCNTn value is copied into ICRn Register. If enabled (TICIEn = 1), the input capture flag generates an input capture interrupt. The ICFn flag is automatically cleared when the interrupt is executed. Alternatively the ICFn flag can be cleared by software by writing a logical one to its I/O bit location. ICFn (int.req.) Analog comparator WRITE ICRn (16-bit register) ICRnH (8-bit) Noise canceler ICPn Edge detector TEMP (8-bit) DATA BUS (8-bit) ICRnL (8-bit) TCNTn (16-bit counter) TCNTnH (8-bit) TCNTnL (8-bit) ACO* ACIC* ICNC ICES123 7593L–AVR–09/12 AT90USB64/128 Reading the 16-bit value in the Input Capture Register (ICRn) is done by first reading the low byte (ICRnL) and then the high byte (ICRnH). When the low byte is read the high byte is copied into the high byte Temporary Register (TEMP). When the CPU reads the ICRnH I/O location it will access the TEMP Register. The ICRn Register can only be written when using a Waveform Generation mode that utilizes the ICRn Register for defining the counter’s TOP value. In these cases the Waveform Generation mode (WGMn3:0) bits must be set before the TOP value can be written to the ICRn Register. When writing the ICRn Register the high byte must be written to the ICRnH I/O location before the low byte is written to ICRnL. For more information on how to access the 16-bit registers refer to Section “Accessing 16-bit registers” on page 117. 15.5.1 Input Capture Trigger Source The main trigger source for the input capture unit is the Input Capture Pin (ICPn). Timer/Counter1 can alternatively use the analog comparator output as trigger source for the input capture unit. The Analog Comparator is selected as trigger source by setting the analog Comparator Input Capture (ACIC) bit in the Analog Comparator Control and Status Register (ACSR). Be aware that changing trigger source can trigger a capture. The input capture flag must therefore be cleared after the change. Both the Input Capture Pin (ICPn) and the Analog Comparator output (ACO) inputs are sampled using the same technique as for the Tn pin (Figure 13-1 on page 96). The edge detector is also identical. However, when the noise canceler is enabled, additional logic is inserted before the edge detector, which increases the delay by four system clock cycles. Note that the input of the noise canceler and edge detector is always enabled unless the Timer/Counter is set in a Waveform Generation mode that uses ICRn to define TOP. An input capture can be triggered by software by controlling the port of the ICPn pin. 15.5.2 Noise Canceler The Noise Canceler improves noise immunity by using a simple digital filtering scheme. The noise canceler input is monitored over four samples, and all four must be equal for changing the output that in turn is used by the edge detector. The noise canceler is enabled by setting the Input Capture Noise Canceler (ICNCn) bit in Timer/Counter Control Register B (TCCRnB). When enabled the noise canceler introduces additional four system clock cycles of delay from a change applied to the input, to the update of the ICRn Register. The noise canceler uses the system clock and is therefore not affected by the prescaler. 15.5.3 Using the Input Capture unit The main challenge when using the Input Capture unit is to assign enough processor capacity for handling the incoming events. The time between two events is critical. If the processor has not read the captured value in the ICRn Register before the next event occurs, the ICRn will be overwritten with a new value. In this case the result of the capture will be incorrect. When using the Input Capture interrupt, the ICRn Register should be read as early in the interrupt handler routine as possible. Even though the Input Capture interrupt has relatively high priority, the maximum interrupt response time is dependent on the maximum number of clock cycles it takes to handle any of the other interrupt requests.124 7593L–AVR–09/12 AT90USB64/128 Using the Input Capture unit in any mode of operation when the TOP value (resolution) is actively changed during operation, is not recommended. Measurement of an external signal’s duty cycle requires that the trigger edge is changed after each capture. Changing the edge sensing must be done as early as possible after the ICRn Register has been read. After a change of the edge, the Input Capture Flag (ICFn) must be cleared by software (writing a logical one to the I/O bit location). For measuring frequency only, the clearing of the ICFn Flag is not required (if an interrupt handler is used). 15.6 Output Compare units The 16-bit comparator continuously compares TCNTn with the Output Compare Register (OCRnx). If TCNT equals OCRnx the comparator signals a match. A match will set the Output Compare Flag (OCFnx) at the next timer clock cycle. If enabled (OCIEnx = 1), the Output Compare Flag generates an Output Compare interrupt. The OCFnx Flag is automatically cleared when the interrupt is executed. Alternatively the OCFnx Flag can be cleared by software by writing a logical one to its I/O bit location. The Waveform Generator uses the match signal to generate an output according to operating mode set by the Waveform Generation mode (WGMn3:0) bits and Compare Output mode (COMnx1:0) bits. The TOP and BOTTOM signals are used by the Waveform Generator for handling the special cases of the extreme values in some modes of operation (see “Modes of operation” on page 127) A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (that is, counter resolution). In addition to the counter resolution, the TOP value defines the period time for waveforms generated by the Waveform Generator. Figure 15-4 shows a block diagram of the Output Compare unit. The small “n” in the register and bit names indicates the device number (n = n for Timer/Counter n), and the “x” indicates Output Compare unit (A/B/C). The elements of the block diagram that are not directly a part of the Output Compare unit are gray shaded. Figure 15-4. Output Compare Unit, block diagram. OCFnx (int.req.) = (16-bit comparator ) OCRnx buffer (16-bit register) OCRnxH buf. (8-bit) OCnx TEMP (8-bit) DATA BUS (8-bit) OCRnxL buf. (8-bit) TCNTn (16-bit counter) TCNTnH (8-bit) TCNTnL (8-bit) WGMn3:0 COMnx1:0 OCRnx (16-bit register) OCRnxH (8-bit) OCRnxL (8-bit) Waveform generator TOP BOTTOM125 7593L–AVR–09/12 AT90USB64/128 The OCRnx Register is double buffered when using any of the twelve Pulse Width Modulation (PWM) modes. For the Normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCRnx Compare Register to either TOP or BOTTOM of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCRnx Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCRnx Buffer Register, and if double buffering is disabled the CPU will access the OCRnx directly. The content of the OCR1x (Buffer or Compare) Register is only changed by a write operation (the Timer/Counter does not update this register automatically as the TCNT1 and ICR1 Register). Therefore OCR1x is not read via the high byte temporary register (TEMP). However, it is a good practice to read the low byte first as when accessing other 16-bit registers. Writing the OCRnx Registers must be done via the TEMP Register since the compare of all 16 bits is done continuously. The high byte (OCRnxH) has to be written first. When the high byte I/O location is written by the CPU, the TEMP Register will be updated by the value written. Then when the low byte (OCRnxL) is written to the lower eight bits, the high byte will be copied into the upper 8-bits of either the OCRnx buffer or OCRnx Compare Register in the same system clock cycle. For more information of how to access the 16-bit registers refer to Section “Accessing 16-bit registers” on page 117. 15.6.1 Force Output Compare In non-PWM Waveform Generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOCnx) bit. Forcing compare match will not set the OCFnx Flag or reload/clear the timer, but the OCnx pin will be updated as if a real compare match had occurred (the COMn1:0 bits settings define whether the OCnx pin is set, cleared or toggled). 15.6.2 Compare Match Blocking by TCNTn write All CPU writes to the TCNTn Register will block any compare match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCRnx to be initialized to the same value as TCNTn without triggering an interrupt when the Timer/Counter clock is enabled. 15.6.3 Using the Output Compare unit Since writing TCNTn in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNTn when using any of the Output Compare channels, independent of whether the Timer/Counter is running or not. If the value written to TCNTn equals the OCRnx value, the compare match will be missed, resulting in incorrect waveform generation. Do not write the TCNTn equal to TOP in PWM modes with variable TOP values. The compare match for the TOP will be ignored and the counter will continue to 0xFFFF. Similarly, do not write the TCNTn value equal to BOTTOM when the counter is counting down. The setup of the OCnx should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OCnx value is to use the Force Output Compare (FOCnx) strobe bits in Normal mode. The OCnx Register keeps its value even when changing between Waveform Generation modes. Be aware that the COMnx1:0 bits are not double buffered together with the compare value. Changing the COMnx1:0 bits will take effect immediately.126 7593L–AVR–09/12 AT90USB64/128 15.7 Compare Match Output unit The Compare Output mode (COMnx1:0) bits have two functions. The Waveform Generator uses the COMnx1:0 bits for defining the Output Compare (OCnx) state at the next compare match. Secondly the COMnx1:0 bits control the OCnx pin output source. Figure 15-5 shows a simplified schematic of the logic affected by the COMnx1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COMnx1:0 bits are shown. When referring to the OCnx state, the reference is for the internal OCnx Register, not the OCnx pin. If a system reset occur, the OCnx Register is reset to “0”. Figure 15-5. Compare Match Output unit, schematic. The general I/O port function is overridden by the Output Compare (OCnx) from the Waveform Generator if either of the COMnx1:0 bits are set. However, the OCnx pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OCnx pin (DDR_OCnx) must be set as output before the OCnx value is visible on the pin. The port override function is generally independent of the Waveform Generation mode, but there are some exceptions. Refer to Table 15-1 on page 137, Table 15-2 on page 137, and Table 15-3 on page 138 for details. The design of the Output Compare pin logic allows initialization of the OCnx state before the output is enabled. Note that some COMnx1:0 bit settings are reserved for certain modes of operation. See “16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3)” on page 115. The COMnx1:0 bits have no effect on the Input Capture unit. 15.7.1 Compare Output mode and Waveform generation The Waveform Generator uses the COMnx1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COMnx1:0 = 0 tells the Waveform Generator that no action on the OCnx Register is to be performed on the next compare match. For compare output actions in the PORT DDR D Q D Q OCnx OCnx pin D Q Waveform generator COMnx1 COMnx0 0 1 DATA BUS FOCnx clkI/O127 7593L–AVR–09/12 AT90USB64/128 non-PWM modes refer to Table 15-1 on page 137. For fast PWM mode refer to Table 15-2 on page 137, and for phase correct and phase and frequency correct PWM refer to Table 15-3 on page 138. A change of the COMnx1:0 bits state will have effect at the first compare match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOCnx strobe bits. 15.8 Modes of operation The mode of operation, that is, the behavior of the Timer/Counter and the Output Compare pins, is defined by the combination of the Waveform Generation mode (WGMn3:0) and Compare Output mode (COMnx1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COMnx1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COMnx1:0 bits control whether the output should be set, cleared or toggle at a compare match (see “Compare Match Output unit” on page 126). For detailed timing information refer to “Timer/Counter timing diagrams” on page 134. 15.8.1 Normal mode The simplest mode of operation is the Normal mode (WGMn3:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 16-bit value (MAX = 0xFFFF) and then restarts from the BOTTOM (0x0000). In normal operation the Timer/Counter Overflow Flag (TOVn) will be set in the same timer clock cycle as the TCNTn becomes zero. The TOVn Flag in this case behaves like a 17th bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOVn Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Input Capture unit is easy to use in Normal mode. However, observe that the maximum interval between the external events must not exceed the resolution of the counter. If the interval between events are too long, the timer overflow interrupt or the prescaler must be used to extend the resolution for the capture unit. The Output Compare units can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 15.8.2 Clear Timer on Compare Match (CTC) mode In Clear Timer on Compare or CTC mode (WGMn3:0 = 4 or 12), the OCRnA or ICRn Register are used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNTn) matches either the OCRnA (WGMn3:0 = 4) or the ICRn (WGMn3:0 = 12). The OCRnA or ICRn define the top value for the counter, hence also its resolution. This mode allows greater control of the compare match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 15-6 on page 128. The counter value (TCNTn) increases until a compare match occurs with either OCRnA or ICRn, and then counter (TCNTn) is cleared.128 7593L–AVR–09/12 AT90USB64/128 Figure 15-6. CTC mode, timing diagram. An interrupt can be generated at each time the counter value reaches the TOP value by either using the OCFnA or ICFn Flag according to the register used to define the TOP value. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCRnA or ICRn is lower than the current value of TCNTn, the counter will miss the compare match. The counter will then have to count to its maximum value (0xFFFF) and wrap around starting at 0x0000 before the compare match can occur. In many cases this feature is not desirable. An alternative will then be to use the fast PWM mode using OCRnA for defining TOP (WGMn3:0 = 15) since the OCRnA then will be double buffered. For generating a waveform output in CTC mode, the OCnA output can be set to toggle its logical level on each compare match by setting the Compare Output mode bits to toggle mode (COMnA1:0 = 1). The OCnA value will not be visible on the port pin unless the data direction for the pin is set to output (DDR_OCnA = 1). The waveform generated will have a maximum frequency of fOCnA = fclk_I/O/2 when OCRnA is set to zero (0x0000). The waveform frequency is defined by the following equation: The N variable represents the prescaler factor (1, 8, 64, 256, or 1024). As for the Normal mode of operation, the TOVn Flag is set in the same timer clock cycle that the counter counts from MAX to 0x0000. 15.8.3 Fast PWM mode The fast Pulse Width Modulation or fast PWM mode (WGMn3:0 = 5, 6, 7, 14, or 15) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM options by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. In non-inverting Compare Output mode, the Output Compare (OCnx) is set on the compare match between TCNTn and OCRnx, and cleared at TOP. In inverting Compare Output mode output is cleared on compare match and set at TOP. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct and phase and frequency correct PWM modes that use dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), hence reduces total system cost. TCNTn OCnA (Toggle) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (interrupt on TOP) Period 1 2 3 4 (COMnA1:0 = 1) f OCnA f clk_I/O 2 ⋅ ⋅ N ( ) 1 + OCRnA = --------------------------------------------------129 7593L–AVR–09/12 AT90USB64/128 The PWM resolution for fast PWM can be fixed to 8-, 9-, or 10-bit, or defined by either ICRn or OCRnA. The minimum resolution allowed is 2-bit (ICRn or OCRnA set to 0x0003), and the maximum resolution is 16-bit (ICRn or OCRnA set to MAX). The PWM resolution in bits can be calculated by using the following equation: In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGMn3:0 = 5, 6, or 7), the value in ICRn (WGMn3:0 = 14), or the value in OCRnA (WGMn3:0 = 15). The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 15-7. The figure shows fast PWM mode when OCRnA or ICRn is used to define TOP. The TCNTn value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNTn slopes represent compare matches between OCRnx and TCNTn. The OCnx Interrupt Flag will be set when a compare match occurs. Figure 15-7. Fast PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOVn) is set each time the counter reaches TOP. In addition the OCnA or ICFn Flag is set at the same timer clock cycle as TOVn is set when either OCRnA or ICRn is used for defining the TOP value. If one of the interrupts are enabled, the interrupt handler routine can be used for updating the TOP and compare values. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a compare match will never occur between the TCNTn and the OCRnx. Note that when using fixed TOP values the unused bits are masked to zero when any of the OCRnx Registers are written. The procedure for updating ICRn differs from updating OCRnA when used for defining the TOP value. The ICRn Register is not double buffered. This means that if ICRn is changed to a low value when the counter is running with none or a low prescaler value, there is a risk that the new ICRn value written is lower than the current value of TCNTn. The result will then be that the counter will miss the compare match at the TOP value. The counter will then have to count to the MAX value (0xFFFF) and wrap around starting at 0x0000 before the compare match can occur. The OCRnA Register however, is double buffered. This feature allows the OCRnA I/O location RFPWM log( ) TOP + 1 log( ) 2 = ----------------------------------- TCNTn OCRnx / TOP Update and TOVn Interrupt Flag Set and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (Interrupt on TOP) Period 1 2 3 4 5 6 7 8 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)130 7593L–AVR–09/12 AT90USB64/128 to be written anytime. When the OCRnA I/O location is written the value written will be put into the OCRnA Buffer Register. The OCRnA Compare Register will then be updated with the value in the Buffer Register at the next timer clock cycle the TCNTn matches TOP. The update is done at the same timer clock cycle as the TCNTn is cleared and the TOVn Flag is set. Using the ICRn Register for defining TOP works well when using fixed TOP values. By using ICRn, the OCRnA Register is free to be used for generating a PWM output on OCnA. However, if the base PWM frequency is actively changed (by changing the TOP value), using the OCRnA as TOP is clearly a better choice due to its double buffer feature. In fast PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COMnx1:0 to three (see Table on page 137). The actual OCnx value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OCnx). The PWM waveform is generated by setting (or clearing) the OCnx Register at the compare match between OCRnx and TCNTn, and clearing (or setting) the OCnx Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCRnx Register represents special cases when generating a PWM waveform output in the fast PWM mode. If the OCRnx is set equal to BOTTOM (0x0000) the output will be a narrow spike for each TOP+1 timer clock cycle. Setting the OCRnx equal to TOP will result in a constant high or low output (depending on the polarity of the output set by the COMnx1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OCnA to toggle its logical level on each compare match (COMnA1:0 = 1). This applies only if OCR1A is used to define the TOP value (WGM13:0 = 15). The waveform generated will have a maximum frequency of fOCnA = fclk_I/O/2 when OCRnA is set to zero (0x0000). This feature is similar to the OCnA toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 15.8.4 Phase correct PWM mode The phase correct Pulse Width Modulation or phase correct PWM mode (WGMn3:0 = 1, 2, 3, 10, or 11) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is, like the phase and frequency correct PWM mode, based on a dualslope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OCnx) is cleared on the compare match between TCNTn and OCRnx while upcounting, and set on the compare match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The PWM resolution for the phase correct PWM mode can be fixed to 8-, 9-, or 10-bit, or defined by either ICRn or OCRnA. The minimum resolution allowed is 2-bit (ICRn or OCRnA set to f OCnxPWM f clk_I/O N ⋅ ( ) 1 + TOP = -----------------------------------131 7593L–AVR–09/12 AT90USB64/128 0x0003), and the maximum resolution is 16-bit (ICRn or OCRnA set to MAX). The PWM resolution in bits can be calculated by using the following equation: In phase correct PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGMn3:0 = 1, 2, or 3), the value in ICRn (WGMn3:0 = 10), or the value in OCRnA (WGMn3:0 = 11). The counter has then reached the TOP and changes the count direction. The TCNTn value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 15-8. The figure shows phase correct PWM mode when OCRnA or ICRn is used to define TOP. The TCNTn value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNTn slopes represent compare matches between OCRnx and TCNTn. The OCnx Interrupt Flag will be set when a compare match occurs. Figure 15-8. Phase correct PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOVn) is set each time the counter reaches BOTTOM. When either OCRnA or ICRn is used for defining the TOP value, the OCnA or ICFn Flag is set accordingly at the same timer clock cycle as the OCRnx Registers are updated with the double buffer value (at TOP). The Interrupt Flags can be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a compare match will never occur between the TCNTn and the OCRnx. Note that when using fixed TOP values, the unused bits are masked to zero when any of the OCRnx Registers are written. As the third period shown in Figure 15-8 illustrates, changing the TOP actively while the Timer/Counter is running in the phase correct mode can result in an unsymmetrical output. The reason for this can be found in the time of update of the OCRnx RegRPCPWM log( ) TOP + 1 log( ) 2 = ----------------------------------- OCRnx/TOP Update and OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (interrupt on TOP) 1 2 3 4 TOVn Interrupt Flag Set (interrupt on Bottom) TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)132 7593L–AVR–09/12 AT90USB64/128 ister. Since the OCRnx update occurs at TOP, the PWM period starts and ends at TOP. This implies that the length of the falling slope is determined by the previous TOP value, while the length of the rising slope is determined by the new TOP value. When these two values differ the two slopes of the period will differ in length. The difference in length gives the unsymmetrical result on the output. It is recommended to use the phase and frequency correct mode instead of the phase correct mode when changing the TOP value while the Timer/Counter is running. When using a static TOP value there are practically no differences between the two modes of operation. In phase correct PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COMnx1:0 to three (see Table 15-3 on page 138). The actual OCnx value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OCnx). The PWM waveform is generated by setting (or clearing) the OCnx Register at the compare match between OCRnx and TCNTn when the counter increments, and clearing (or setting) the OCnx Register at compare match between OCRnx and TCNTn when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCRnx Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCRnx is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WGM13:0 = 11) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. 15.8.5 Phase and frequency correct PWM mode The phase and frequency correct Pulse Width Modulation, or phase and frequency correct PWM mode (WGMn3:0 = 8 or 9) provides a high resolution phase and frequency correct PWM waveform generation option. The phase and frequency correct PWM mode is, like the phase correct PWM mode, based on a dual-slope operation. The counter counts repeatedly from BOTTOM (0x0000) to TOP and then from TOP to BOTTOM. In non-inverting Compare Output mode, the Output Compare (OCnx) is cleared on the compare match between TCNTn and OCRnx while upcounting, and set on the compare match while downcounting. In inverting Compare Output mode, the operation is inverted. The dual-slope operation gives a lower maximum operation frequency compared to the single-slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. The main difference between the phase correct, and the phase and frequency correct PWM mode is the time the OCRnx Register is updated by the OCRnx Buffer Register, (see Figure 15- 8 on page 131 and Figure 15-9 on page 133). The PWM resolution for the phase and frequency correct PWM mode can be defined by either ICRn or OCRnA. The minimum resolution allowed is 2-bit (ICRn or OCRnA set to 0x0003), and f OCnxPCPWM f clk_I/O 2 ⋅ ⋅ N TOP = ----------------------------133 7593L–AVR–09/12 AT90USB64/128 the maximum resolution is 16-bit (ICRn or OCRnA set to MAX). The PWM resolution in bits can be calculated using the following equation: In phase and frequency correct PWM mode the counter is incremented until the counter value matches either the value in ICRn (WGMn3:0 = 8), or the value in OCRnA (WGMn3:0 = 9). The counter has then reached the TOP and changes the count direction. The TCNTn value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct and frequency correct PWM mode is shown on Figure 15-9. The figure shows phase and frequency correct PWM mode when OCRnA or ICRn is used to define TOP. The TCNTn value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes noninverted and inverted PWM outputs. The small horizontal line marks on the TCNTn slopes represent compare matches between OCRnx and TCNTn. The OCnx Interrupt Flag will be set when a compare match occurs. Figure 15-9. Phase and frequency correct PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOVn) is set at the same timer clock cycle as the OCRnx Registers are updated with the double buffer value (at BOTTOM). When either OCRnA or ICRn is used for defining the TOP value, the OCnA or ICFn Flag set when TCNTn has reached TOP. The Interrupt Flags can then be used to generate an interrupt each time the counter reaches the TOP or BOTTOM value. When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the Compare Registers. If the TOP value is lower than any of the Compare Registers, a compare match will never occur between the TCNTn and the OCRnx. As Figure 15-9 shows the output generated is, in contrast to the phase correct mode, symmetrical in all periods. Since the OCRnx Registers are updated at BOTTOM, the length of the rising and the falling slopes will always be equal. This gives symmetrical output pulses and is therefore frequency correct. RPFCPWM log( ) TOP + 1 log( ) 2 = ----------------------------------- OCRnx/TOP Updateand TOVn Interrupt Flag Set (interrupt on Bottom) OCnA Interrupt Flag Set or ICFn Interrupt Flag Set (interrupt on TOP) 1 2 3 4 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3)134 7593L–AVR–09/12 AT90USB64/128 Using the ICRn Register for defining TOP works well when using fixed TOP values. By using ICRn, the OCRnA Register is free to be used for generating a PWM output on OCnA. However, if the base PWM frequency is actively changed by changing the TOP value, using the OCRnA as TOP is clearly a better choice due to its double buffer feature. In phase and frequency correct PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COMnx1:0 to three (see Table 15-3 on page 138). The actual OCnx value will only be visible on the port pin if the data direction for the port pin is set as output (DDR_OCnx). The PWM waveform is generated by setting (or clearing) the OCnx Register at the compare match between OCRnx and TCNTn when the counter increments, and clearing (or setting) the OCnx Register at compare match between OCRnx and TCNTn when the counter decrements. The PWM frequency for the output when using phase and frequency correct PWM can be calculated by the following equation: The N variable represents the prescaler divider (1, 8, 64, 256, or 1024). The extreme values for the OCRnx Register represents special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCRnx is set equal to BOTTOM the output will be continuously low and if set equal to TOP the output will be set to high for noninverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty cycle. 15.9 Timer/Counter timing diagrams The Timer/Counter is a synchronous design and the timer clock (clkTn) is therefore shown as a clock enable signal in the following figures. The figures include information on when Interrupt Flags are set, and when the OCRnx Register is updated with the OCRnx buffer value (only for modes utilizing double buffering). Figure 15-10 shows a timing diagram for the setting of OCFnx. Figure 15-10. Timer/Counter timing diagram, setting of OCFnx, no prescaling. Figure 15-11 on page 135 shows the same timing data, but with the prescaler enabled. f OCnxPFCPWM f clk_I/O 2 ⋅ ⋅ N TOP = ---------------------------- clkTn (clkI/O/1) OCFnx clkI/O OCRnx TCNTn OCRnx value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2135 7593L–AVR–09/12 AT90USB64/128 Figure 15-11. Timer/Counter timing diagram, setting of OCFnx, with prescaler (fclk_I/O/8). Figure 15-12 shows the count sequence close to TOP in various modes. When using phase and frequency correct PWM mode the OCRnx Register is updated at BOTTOM. The timing diagrams will be the same, but TOP should be replaced by BOTTOM, TOP-1 by BOTTOM+1 and so on. The same renaming applies for modes that set the TOVn Flag at BOTTOM. Figure 15-12. Timer/Counter timing diagram, no prescaling. Figure 15-13 on page 136 shows the same timing data, but with the prescaler enabled. OCFnx OCRnx TCNTn OCRnx value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8) TOVn (FPWM) and ICFn (if used as TOP) OCRnx (update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx value New OCRnx value TOP - 1 TOP BOTTOM BOTTOM + 1 clkTn (clkI/O/1) clkI/O136 7593L–AVR–09/12 AT90USB64/128 Figure 15-13. Timer/Counter timing diagram, with prescaler (fclk_I/O/8). 15.10 16-bit Timer/Counter register description 15.10.1 TCCR1A – Timer/Counter1 Control Register A 15.10.2 TCCR3A – Timer/Counter3 Control Register A • Bit 7:6 – COMnA1:0: Compare Output Mode for Channel A • Bit 5:4 – COMnB1:0: Compare Output Mode for Channel B • Bit 3:2 – COMnC1:0: Compare Output Mode for Channel C The COMnA1:0, COMnB1:0, and COMnC1:0 control the output compare pins (OCnA, OCnB, and OCnC respectively) behavior. If one or both of the COMnA1:0 bits are written to one, the OCnA output overrides the normal port functionality of the I/O pin it is connected to. If one or both of the COMnB1:0 bits are written to one, the OCnB output overrides the normal port functionality of the I/O pin it is connected to. If one or both of the COMnC1:0 bits are written to one, the OCnC output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OCnA, OCnB or OCnC pin must be set in order to enable the output driver. TOVn (FPWM) and ICFn (if used as TOP) OCRnx (update at TOP) TCNTn (CTC and FPWM) TCNTn (PC and PFC PWM) TOP - 1 TOP TOP - 1 TOP - 2 Old OCRnx value New OCRnx value TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clk Tn (clkI/O /8) Bit 7 6 5 4 3 2 1 0 COM1A1 COM1A0 COM1B1 COM1B0 COM1C1 COM1C0 WGM11 WGM10 TCCR1A Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 COM3A1 COM3A0 COM3B1 COM3B0 COM3C1 COM3C0 WGM31 WGM30 TCCR3A Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0137 7593L–AVR–09/12 AT90USB64/128 When the OCnA, OCnB or OCnC is connected to the pin, the function of the COMnx1:0 bits is dependent of the WGMn3:0 bits setting. Table 15-1 shows the COMnx1:0 bit functionality when the WGMn3:0 bits are set to a normal or a CTC mode (non-PWM). Table 15-2 shows the COMnx1:0 bit functionality when the WGMn3:0 bits are set to the fast PWM mode. Note: A special case occurs when OCRnA/OCRnB/OCRnC equals TOP and COMnA1/COMnB1/COMnC1 is set. In this case the compare match is ignored, but the set or clear is done at TOP. See “Fast PWM mode” on page 104. for more details. Table 15-3 on page 138 shows the COMnx1:0 bit functionality when the WGMn3:0 bits are set to the phase correct and frequency correct PWM mode. Table 15-1. Compare Output mode, non-PWM. COMnA1/COMnB1/ COMnC1 COMnA0/COMnB0/ COMnC0 Description 0 0 Normal port operation, OCnA/OCnB/OCnC disconnected. 0 1 Toggle OCnA/OCnB/OCnC on compare match. 1 0 Clear OCnA/OCnB/OCnC on compare match (set output to low level). 1 1 Set OCnA/OCnB/OCnC on compare match (set output to high level). Table 15-2. Compare Output mode, fast PWM. COMnA1/COMnB1/ COMnC0 COMnA0/COMnB0/ COMnC0 Description 0 0 Normal port operation, OCnA/OCnB/OCnC disconnected. 0 1 WGM13:0 = 14 or 15: Toggle OC1A on Compare Match, OC1B and OC1C disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B/OC1C disconnected. 1 0 Clear OCnA/OCnB/OCnC on compare match, set OCnA/OCnB/OCnC at TOP 1 1 Set OCnA/OCnB/OCnC on compare match, clear OCnA/OCnB/OCnC at TOP138 7593L–AVR–09/12 AT90USB64/128 Note: A special case occurs when OCRnA/OCRnB/OCRnC equals TOP and COMnA1/COMnB1//COMnC1 is set. See “Phase correct PWM mode” on page 106. for more details. • Bit 1:0 – WGMn1:0: Waveform Generation mode Combined with the WGMn3:2 bits found in the TCCRnB Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 15-4 on page 138. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare match (CTC) mode, and three types of Pulse Width Modulation (PWM) modes. (See “Modes of operation” on page 103.). Table 15-3. Compare Output mode, phase correct and phase and frequency correct PWM. COMnA1/COMnB/ COMnC1 COMnA0/COMnB0/ COMnC0 Description 0 0 Normal port operation, OCnA/OCnB/OCnC disconnected. 0 1 WGM13:0 = 8, 9 10 or 11: Toggle OC1A on Compare Match, OC1B and OC1C disconnected (normal port operation). For all other WGM1 settings, normal port operation, OC1A/OC1B/OC1C disconnected. 1 0 Clear OCnA/OCnB/OCnC on compare match when up-counting. Set OCnA/OCnB/OCnC on compare match when counting down. 1 1 Set OCnA/OCnB/OCnC on compare match when up-counting. Clear OCnA/OCnB/OCnC on compare match when counting down. Table 15-4. Waveform Generation mode bit description (1). Mode WGMn3 WGMn2 (CTCn) WGMn1 (PWMn1) WGMn0 (PWMn0) Timer/Counter mode of operation TOP Update of OCRnx at TOVn flag set on 0 0 0 0 0 Normal 0xFFFF Immediate MAX 1 0 0 0 1 PWM, phase correct, 8-bit 0x00FF TOP BOTTOM 2 0 0 1 0 PWM, phase correct, 9-bit 0x01FF TOP BOTTOM 3 0 0 1 1 PWM, phase correct, 10-bit 0x03FF TOP BOTTOM 4 0 1 0 0 CTC OCRnA Immediate MAX 5 0 1 0 1 Fast PWM, 8-bit 0x00FF TOP TOP 6 0 1 1 0 Fast PWM, 9-bit 0x01FF TOP TOP 7 0 1 1 1 Fast PWM, 10-bit 0x03FF TOP TOP 81 0 0 0 PWM, phase and frequency Correct ICRn BOTTOM BOTTOM 91 0 0 1 PWM, phase and frequency Correct OCRnA BOTTOM BOTTOM 10 1 0 1 0 PWM, phase correct ICRn TOP BOTTOM139 7593L–AVR–09/12 AT90USB64/128 Note: 1. The CTCn and PWMn1:0 bit definition names are obsolete. Use the WGMn2:0 definitions. However, the functionality and location of these bits are compatible with previous versions of the timer. 15.10.3 TCCR1B – Timer/Counter1 Control Register B 15.10.4 TCCR3B – Timer/Counter3 Control Register B • Bit 7 – ICNCn: Input Capture Noise Canceler Setting this bit (to one) activates the Input Capture Noise Canceler. When the Noise Canceler is activated, the input from the Input Capture Pin (ICPn) is filtered. The filter function requires four successive equal valued samples of the ICPn pin for changing its output. The input capture is therefore delayed by four Oscillator cycles when the noise canceler is enabled. • Bit 6 – ICESn: Input Capture Edge Select This bit selects which edge on the Input Capture Pin (ICPn) that is used to trigger a capture event. When the ICESn bit is written to zero, a falling (negative) edge is used as trigger, and when the ICESn bit is written to one, a rising (positive) edge will trigger the capture. When a capture is triggered according to the ICESn setting, the counter value is copied into the Input Capture Register (ICRn). The event will also set the Input Capture Flag (ICFn), and this can be used to cause an Input Capture Interrupt, if this interrupt is enabled. When the ICRn is used as TOP value (see description of the WGMn3:0 bits located in the TCCRnA and the TCCRnB Register), the ICPn is disconnected and consequently the input capture function is disabled. • Bit 5 – Reserved bit This bit is reserved for future use. For ensuring compatibility with future devices, this bit must be written to zero when TCCRnB is written. • Bit 4:3 – WGMn3:2: Waveform Generation mode See TCCRnA Register description. 11 1 0 1 1 PWM, phase correct OCRnA TOP BOTTOM 12 1 1 0 0 CTC ICRn Immediate MAX 13 1 1 0 1 (Reserved) – – – 14 1 1 1 0 Fast PWM ICRn TOP TOP 15 1 1 1 1 Fast PWM OCRnA TOP TOP Table 15-4. Waveform Generation mode bit description (1). (Continued) Mode WGMn3 WGMn2 (CTCn) WGMn1 (PWMn1) WGMn0 (PWMn0) Timer/Counter mode of operation TOP Update of OCRnx at TOVn flag set on Bit 7 6 5 4 3 2 1 0 ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 TCCR1B Read/write R/W R/W R R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 ICNC3 ICES3 – WGM33 WGM32 CS32 CS31 CS30 TCCR3B Read/write R/W R/W R R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0140 7593L–AVR–09/12 AT90USB64/128 • Bit 2:0 – CSn2:0: Clock Select The three clock select bits select the clock source to be used by the Timer/Counter, see Figure 14-8 on page 107 and Figure 14-9 on page 108. If external pin modes are used for the Timer/Countern, transitions on the Tn pin will clock the counter even if the pin is configured as an output. This feature allows software control of the counting. 15.10.5 TCCR1C – Timer/Counter1 Control Register C 15.10.6 TCCR3C – Timer/Counter3 Control Register C • Bit 7 – FOCnA: Force Output Compare for Channel A • Bit 6 – FOCnB: Force Output Compare for Channel B • Bit 5 – FOCnC: Force Output Compare for Channel C The FOCnA/FOCnB/FOCnC bits are only active when the WGMn3:0 bits specifies a non-PWM mode. When writing a logical one to the FOCnA/FOCnB/FOCnC bit, an immediate compare match is forced on the waveform generation unit. The OCnA/OCnB/OCnC output is changed according to its COMnx1:0 bits setting. Note that the FOCnA/FOCnB/FOCnC bits are implemented as strobes. Therefore it is the value present in the COMnx1:0 bits that determine the effect of the forced compare. A FOCnA/FOCnB/FOCnC strobe will not generate any interrupt nor will it clear the timer in Clear Timer on Compare Match (CTC) mode using OCRnA as TOP. The FOCnA/FOCnB/FOCnB bits are always read as zero. • Bit 4:0 – Reserved bits These bits are reserved for future use. For ensuring compatibility with future devices, these bits must be written to zero when TCCRnC is written. Table 15-5. Clock Select bit description. CSn2 CSn1 CSn0 Description 0 0 0 No clock source. (Timer/Counter stopped) 0 0 1 clkI/O/1 (no prescaling 0 1 0 clkI/O/8 (from prescaler) 0 1 1 clkI/O/64 (from prescaler) 1 0 0 clkI/O/256 (from prescaler) 1 0 1 clkI/O/1024 (from prescaler) 1 1 0 External clock source on Tn pin. Clock on falling edge 1 1 1 External clock source on Tn pin. Clock on rising edge Bit 7 6 5 4 3 2 1 0 FOC1A FOC1B FOC1C – – – – – TCCR1C Read/write W W W R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 FOC3A FOC3B FOC3C – – – – – TCCR3C Read/write W W W R R R R R Initial value 0 0 0 0 0 0 0 0141 7593L–AVR–09/12 AT90USB64/128 15.10.7 TCNT1H and TCNT1L – Timer/Counter1 15.10.8 TCNT3H and TCNT3L – Timer/Counter3 The two Timer/Counter I/O locations (TCNTnH and TCNTnL, combined TCNTn) give direct access, both for read and for write operations, to the Timer/Counter unit 16-bit counter. To ensure that both the high and low bytes are read and written simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit registers” on page 117. Modifying the counter (TCNTn) while the counter is running introduces a risk of missing a compare match between TCNTn and one of the OCRnx Registers. Writing to the TCNTn Register blocks (removes) the compare match on the following timer clock for all compare units. 15.10.9 OCR1AH and OCR1AL – Output Compare Register 1 A 15.10.10 OCR1BH and OCR1BL – Output Compare Register 1 B 15.10.11 OCR1CH and OCR1CL – Output Compare Register 1 C Bit 7 6 5 4 3 2 1 0 TCNT1[15:8] TCNT1H TCNT1[7:0] TCNT1L Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 TCNT3[15:8] TCNT3H TCNT3[7:0] TCNT3L Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1A[15:8] OCR1AH OCR1A[7:0] OCR1AL Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1B[15:8] OCR1BH OCR1B[7:0] OCR1BL Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR1C[15:8] OCR1CH OCR1C[7:0] OCR1CL Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0142 7593L–AVR–09/12 AT90USB64/128 15.10.12 OCR3AH and OCR3AL – Output Compare Register 3 A 15.10.13 OCR3BH and OCR3BL – Output Compare Register 3 B 15.10.14 OCR3CH and OCR3CL – Output Compare Register 3 C The Output Compare Registers contain a 16-bit value that is continuously compared with the counter value (TCNTn). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OCnx pin. The Output Compare Registers are 16-bit in size. To ensure that both the high and low bytes are written simultaneously when the CPU writes to these registers, the access is performed using an 8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit registers” on page 117. 15.10.15 ICR1H and ICR1L – Input Capture Register 1 15.10.16 ICR3H and ICR3L – Input Capture Register 3 The Input Capture is updated with the counter (TCNTn) value each time an event occurs on the ICPn pin (or optionally on the Analog Comparator output for Timer/Counter1). The Input Capture can be used for defining the counter TOP value. The Input Capture Register is 16-bit in size. To ensure that both the high and low bytes are read simultaneously when the CPU accesses these registers, the access is performed using an 8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit registers. See “Accessing 16-bit registers” on page 117. Bit 7 6 5 4 3 2 1 0 OCR3A[15:8] OCR3AH OCR3A[7:0] OCR3AL Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR3B[15:8] OCR3BH OCR3B[7:0] OCR3BL Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR3C[15:8] OCR3CH OCR3C[7:0] OCR3CL Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 ICR1[15:8] ICR1H ICR1[7:0] ICR1L Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 ICR3[15:8] ICR3H ICR3[7:0] ICR3L Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0143 7593L–AVR–09/12 AT90USB64/128 15.10.17 TIMSK1 – Timer/Counter1 Interrupt Mask Register 15.10.18 TIMSK3 – Timer/Counter3 Interrupt Mask Register • Bit 5 – ICIEn: Timer/Countern, Input Capture Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Countern Input Capture interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 68) is executed when the ICFn Flag, located in TIFRn, is set. • Bit 3 – OCIEnC: Timer/Countern, Output Compare C Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Countern Output Compare C Match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 68) is executed when the OCFnC Flag, located in TIFRn, is set. • Bit 2 – OCIEnB: Timer/Countern, Output Compare B Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Countern Output Compare B Match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 68) is executed when the OCFnB Flag, located in TIFRn, is set. • Bit 1 – OCIEnA: Timer/Countern, Output Compare A Match Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Countern Output Compare A Match interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 68) is executed when the OCFnA Flag, located in TIFRn, is set. • Bit 0 – TOIEn: Timer/Countern, Overflow Interrupt Enable When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the Timer/Countern Overflow interrupt is enabled. The corresponding Interrupt Vector (see “Interrupts” on page 68) is executed when the TOVn Flag, located in TIFRn, is set. 15.10.19 TIFR1 – Timer/Counter1 Interrupt Flag Register 15.10.20 TIFR3 – Timer/Counter3 Interrupt Flag Register Bit 7 6 5 4 3 2 1 0 – – ICIE1 – OCIE1C OCIE1B OCIE1A TOIE1 TIMSK1 Read/write R R R/W R R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – ICIE3 – OCIE3C OCIE3B OCIE3A TOIE3 TIMSK3 Read/write R R R/W R R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – ICF1 – OCF1C OCF1B OCF1A TOV1 TIFR1 Read/write R R R/W R R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 – – ICF3 – OCF3C OCF3B OCF3A TOV3 TIFR3 Read/write R R R/W R R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0144 7593L–AVR–09/12 AT90USB64/128 • Bit 5 – ICFn: Timer/Countern, Input Capture Flag This flag is set when a capture event occurs on the ICPn pin. When the Input Capture Register (ICRn) is set by the WGMn3:0 to be used as the TOP value, the ICFn Flag is set when the counter reaches the TOP value. ICFn is automatically cleared when the Input Capture Interrupt Vector is executed. Alternatively, ICFn can be cleared by writing a logic one to its bit location. • Bit 3– OCFnC: Timer/Countern, Output Compare C Match Flag This flag is set in the timer clock cycle after the counter (TCNTn) value matches the Output Compare Register C (OCRnC). Note that a Forced Output Compare (FOCnC) strobe will not set the OCFnC Flag. OCFnC is automatically cleared when the Output Compare Match C Interrupt Vector is executed. Alternatively, OCFnC can be cleared by writing a logic one to its bit location. • Bit 2 – OCFnB: Timer/Counter1, Output Compare B Match Flag This flag is set in the timer clock cycle after the counter (TCNTn) value matches the Output Compare Register B (OCRnB). Note that a Forced Output Compare (FOCnB) strobe will not set the OCFnB Flag. OCFnB is automatically cleared when the Output Compare Match B Interrupt Vector is executed. Alternatively, OCFnB can be cleared by writing a logic one to its bit location. • Bit 1 – OCF1A: Timer/Counter1, Output Compare A Match Flag This flag is set in the timer clock cycle after the counter (TCNTn value matches the Output Compare Register A (OCRnA). Note that a Forced Output Compare (FOCnA) strobe will not set the OCFnA Flag. OCFnA is automatically cleared when the Output Compare Match A Interrupt Vector is executed. Alternatively, OCFnA can be cleared by writing a logic one to its bit location. • Bit 0 – TOVn: Timer/Countern, Overflow Flag The setting of this flag is dependent of the WGMn3:0 bits setting. In Normal and CTC modes, the TOVn Flag is set when the timer overflows. Refer to Table 15-4 on page 138 for the TOVn Flag behavior when using another WGMn3:0 bit setting. TOVn is automatically cleared when the Timer/Countern Overflow Interrupt Vector is executed. Alternatively, TOVn can be cleared by writing a logic one to its bit location.145 7593L–AVR–09/12 AT90USB64/128 16. 8-bit Timer/Counter2 with PWM and asynchronous operation Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. The main features are: • Single channel counter • Clear timer on compare match (auto reload) • Glitch-free, phase correct pulse width modulator (PWM) • Frequency generator • 10-bit clock prescaler • Overflow and compare match interrupt sources (TOV2, OCF2A and OCF2B) • Allows clocking from external 32kHz watch crystal independent of the I/O clock 16.1 Overview A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 16-1. For the actual placement of I/O pins, see “Pin configurations” on page 3. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “8-bit Timer/Counter register description” on page 156. The Power Reduction Timer/Counter2 bit, PRTIM2, in “PRR0 – Power Reduction Register 0” on page 54 must be written to zero to enable Timer/Counter2 module. Figure 16-1. 8-bit Timer/Counter, block diagram. Timer/counter DATA BUS OCRnA OCRnB = = TCNTn Waveform generation Waveform generation OCnA OCnB = Fixed TOP value Control logic = 0 TOP BOTTOM Count Clear Direction TOVn (int.req.) OCnA (int.req.) OCnB (int.req.) TCCRnA TCCRnB clkTn ASSRn Synchronization unit Prescaler T/C oscillator clkI/O clkASY asynchronous mode select (ASn) Synchronized status flags TOSC1 TOSC2 Status flags clkI/O146 7593L–AVR–09/12 AT90USB64/128 16.1.1 Registers The Timer/Counter (TCNT2) and Output Compare Register (OCR2A and OCR2B) are 8-bit registers. Interrupt request (abbreviated to Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFR2). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK2). TIFR2 and TIMSK2 are not shown in the figure. The Timer/Counter can be clocked internally, via the prescaler, or asynchronously clocked from the TOSC1/2 pins, as detailed later in this section. The asynchronous operation is controlled by the Asynchronous Status Register (ASSR). The Clock Select logic block controls which clock source the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the Clock Select logic is referred to as the timer clock (clkT2). The double buffered Output Compare Register (OCR2A and OCR2B) are compared with the Timer/Counter value at all times. The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pins (OC2A and OC2B). See “Output Compare unit” on page 147. for details. The compare match event will also set the Compare Flag (OCF2A or OCF2B) which can be used to generate an Output Compare interrupt request. 16.1.2 Definitions Many register and bit references in this document are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 2. However, when using the register or bit defines in a program, the precise form must be used, that is, TCNT2 for accessing Timer/Counter2 counter value and so on. The definitions in the table below are also used extensively throughout the section. 16.2 Timer/Counter clock sources The Timer/Counter can be clocked by an internal synchronous or an external asynchronous clock source. The clock source clkT2 is by default equal to the MCU clock, clkI/O. When the AS2 bit in the ASSR Register is written to logic one, the clock source is taken from the Timer/Counter Oscillator connected to TOSC1 and TOSC2. For details on asynchronous operation, see “ASSR – Asynchronous Status Register” on page 161. For details on clock sources and prescaler, see “Timer/Counter prescaler” on page 164. 16.3 Counter unit The main part of the 8-bit Timer/Counter is the programmable bi-directional counter unit. Figure 16-2 on page 147 shows a block diagram of the counter and its surrounding environment. BOTTOM The counter reaches the BOTTOM when it becomes zero (0x00). MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be the fixed value 0xFF (MAX) or the value stored in the OCR2A Register. The assignment is dependent on the mode of operation.147 7593L–AVR–09/12 AT90USB64/128 Figure 16-2. Counter unit block diagram. Signal description (internal signals): count Increment or decrement TCNT2 by 1. direction Selects between increment and decrement. clear Clear TCNT2 (set all bits to zero). clkTn Timer/Counter clock, referred to as clkT2 in the following. top Signalizes that TCNT2 has reached maximum value. bottom Signalizes that TCNT2 has reached minimum value (zero). Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT2). clkT2 can be generated from an external or internal clock source, selected by the Clock Select bits (CS22:0). When no clock source is selected (CS22:0 = 0) the timer is stopped. However, the TCNT2 value can be accessed by the CPU, regardless of whether clkT2 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the WGM21 and WGM20 bits located in the Timer/Counter Control Register (TCCR2A) and the WGM22 located in the Timer/Counter Control Register B (TCCR2B). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare outputs OC2A and OC2B. For more details about advanced counting sequences and waveform generation, see “Modes of operation” on page 150. The Timer/Counter Overflow Flag (TOV2) is set according to the mode of operation selected by the WGM22:0 bits. TOV2 can be used for generating a CPU interrupt. 16.4 Output Compare unit The 8-bit comparator continuously compares TCNT2 with the Output Compare Register (OCR2A and OCR2B). Whenever TCNT2 equals OCR2A or OCR2B, the comparator signals a match. A match will set the Output Compare Flag (OCF2A or OCF2B) at the next timer clock cycle. If the corresponding interrupt is enabled, the Output Compare Flag generates an Output Compare interrupt. The Output Compare Flag is automatically cleared when the interrupt is executed. Alternatively, the Output Compare Flag can be cleared by software by writing a logical one to its I/O bit location. The Waveform Generator uses the match signal to generate an output according to operating mode set by the WGM22:0 bits and Compare Output mode (COM2x1:0) bits. The max and bottom signals are used by the Waveform Generator for handling the special cases of the extreme values in some modes of operation (“Modes of operation” on page 150). Figure 15-10 on page 134 shows a block diagram of the Output Compare unit. DATA BUS TCNTn Control logic count TOVn (int.req.) bottom top direction clear TOSC1 T/C oscillator TOSC2 Prescaler clkI/O clk Tn148 7593L–AVR–09/12 AT90USB64/128 Figure 16-3. Output Compare unit, block diagram. The OCR2x Register is double buffered when using any of the Pulse Width Modulation (PWM) modes. For the Normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR2x Compare Register to either top or bottom of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR2x Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR2x Buffer Register, and if double buffering is disabled the CPU will access the OCR2x directly. 16.4.1 Force output compare In non-PWM waveform generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC2x) bit. Forcing compare match will not set the OCF2x Flag or reload/clear the timer, but the OC2x pin will be updated as if a real compare match had occurred (the COM2x1:0 bits settings define whether the OC2x pin is set, cleared or toggled). 16.4.2 Compare Match Blocking by TCNT2 Write All CPU write operations to the TCNT2 Register will block any compare match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR2x to be initialized to the same value as TCNT2 without triggering an interrupt when the Timer/Counter clock is enabled. 16.4.3 Using the Output Compare unit Since writing TCNT2 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT2 when using the Output Compare channel, independently of whether the Timer/Counter is running or not. If the value written to TCNT2 equals the OCR2x value, the compare match will be missed, resulting in incorrect waveform generation. Similarly, do not write the TCNT2 value equal to BOTTOM when the counter is downcounting. OCFnx (int.req.) = (8-bit comparator) OCRnx OCnx DATA BUS TCNTn WGMn1:0 Waveform generator top FOCn COMnX1:0 bottom149 7593L–AVR–09/12 AT90USB64/128 The setup of the OC2x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC2x value is to use the Force Output Compare (FOC2x) strobe bit in Normal mode. The OC2x Register keeps its value even when changing between Waveform Generation modes. Be aware that the COM2x1:0 bits are not double buffered together with the compare value. Changing the COM2x1:0 bits will take effect immediately. 16.5 Compare Match Output unit The Compare Output mode (COM2x1:0) bits have two functions. The Waveform Generator uses the COM2x1:0 bits for defining the Output Compare (OC2x) state at the next compare match. Also, the COM2x1:0 bits control the OC2x pin output source. Figure 16-4 shows a simplified schematic of the logic affected by the COM2x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM2x1:0 bits are shown. When referring to the OC2x state, the reference is for the internal OC2x Register, not the OC2x pin. Figure 16-4. Compare Match Output unit, schematic. The general I/O port function is overridden by the Output Compare (OC2x) from the Waveform Generator if either of the COM2x1:0 bits are set. However, the OC2x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC2x pin (DDR_OC2x) must be set as output before the OC2x value is visible on the pin. The port override function is independent of the Waveform Generation mode. The design of the Output Compare pin logic allows initialization of the OC2x state before the output is enabled. Note that some COM2x1:0 bit settings are reserved for certain modes of operation. See “8-bit Timer/Counter register description” on page 156. PORT DDR D Q D Q OCnx OCnx pin D Q Waveform generator COMnx1 COMnx0 0 1 DATA BU S FOCnx clkI/O150 7593L–AVR–09/12 AT90USB64/128 16.5.1 Compare Output mode and Waveform generating The Waveform Generator uses the COM2x1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM2x1:0 = 0 tells the Waveform Generator that no action on the OC2x Register is to be performed on the next compare match. For compare output actions in the non-PWM modes refer to Table 16-4 on page 157. For fast PWM mode, refer to Table 16-5 on page 158, and for phase correct PWM refer to Table 16-6 on page 158. A change of the COM2x1:0 bits state will have effect at the first compare match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC2x strobe bits. 16.6 Modes of operation The mode of operation, that is, the behavior of the Timer/Counter and the Output Compare pins, is defined by the combination of the Waveform Generation mode (WGM22:0) and Compare Output mode (COM2x1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM2x1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM2x1:0 bits control whether the output should be set, cleared, or toggled at a compare match (see “Compare Match Output unit” on page 149). For detailed timing information refer to Section “Timer/Counter timing diagrams” on page 154. 16.6.1 Normal mode The simplest mode of operation is the Normal mode (WGM22:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV2) will be set in the same timer clock cycle as the TCNT2 becomes zero. The TOV2 Flag in this case behaves like a ninth bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV2 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Output Compare unit can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 16.6.2 Clear Timer on Compare Match (CTC) mode In Clear Timer on Compare or CTC mode (WGM22:0 = 2), the OCR2A Register is used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT2) matches the OCR2A. The OCR2A defines the top value for the counter, hence also its resolution. This mode allows greater control of the compare match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Table 16-5 on page 151. The counter value (TCNT2) increases until a compare match occurs between TCNT2 and OCR2A, and then counter (TCNT2) is cleared.151 7593L–AVR–09/12 AT90USB64/128 Figure 16-5. CTC mode, timing diagram. An interrupt can be generated each time the counter value reaches the TOP value by using the OCF2A Flag. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR2A is lower than the current value of TCNT2, the counter will miss the compare match. The counter will then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the compare match can occur. For generating a waveform output in CTC mode, the OC2A output can be set to toggle its logical level on each compare match by setting the Compare Output mode bits to toggle mode (COM2A1:0 = 1). The OC2A value will not be visible on the port pin unless the data direction for the pin is set to output. The waveform generated will have a maximum frequency of fOC2A = fclk_I/O/2 when OCR2A is set to zero (0x00). The waveform frequency is defined by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). As for the Normal mode of operation, the TOV2 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x00. 16.6.3 Fast PWM mode The fast Pulse Width Modulation or fast PWM mode (WGM22:0 = 3 or 7) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM option by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. TOP is defined as 0xFF when WGM22:0 = 3, and OCR2A when MGM22:0 = 7. In noninverting Compare Output mode, the Output Compare (OC2x) is cleared on the compare match between TCNT2 and OCR2x, and set at BOTTOM. In inverting Compare Output mode, the output is set on compare match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct PWM mode that uses dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), and therefore reduces total system cost. TCNTn OCnx (Toggle) OCnx Interrupt Flag Set Period 1 2 3 4 (COMnx1:0 = 1) f OCnx f clk_I/O 2 ⋅ ⋅ N ( ) 1 + OCRnx = -------------------------------------------------152 7593L–AVR–09/12 AT90USB64/128 In fast PWM mode, the counter is incremented until the counter value matches the TOP value. The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 16-6. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2x and TCNT2. Figure 16-6. Fast PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches TOP. If the interrupt is enabled, the interrupt handler routine can be used for updating the compare value. In fast PWM mode, the compare unit allows generation of PWM waveforms on the OC2x pin. Setting the COM2x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM2x1:0 to three. TOP is defined as 0xFF when WGM2:0 = 3, and OCR2A when WGM2:0 = 7 (See Table 16-2 on page 157). The actual OC2x value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by setting (or clearing) the OC2x Register at the compare match between OCR2x and TCNT2, and clearing (or setting) the OC2x Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2A Register represent special cases when generating a PWM waveform output in the fast PWM mode. If the OCR2A is set equal to BOTTOM, the output will be a narrow spike for each MAX+1 timer clock cycle. Setting the OCR2A equal to MAX will result in a constantly high or low output (depending on the polarity of the output set by the COM2A1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC2x to toggle its logical level on each compare match (COM2x1:0 = 1). The waveform TCNTn OCRnx Update and TOVn Interrupt Flag Set Period 1 2 3 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx Interrupt Flag Set 4 5 6 7 f OCnxPWM f clk_I/O N ⋅ 256 = ------------------153 7593L–AVR–09/12 AT90USB64/128 generated will have a maximum frequency of foc2 = fclk_I/O/2 when OCR2A is set to zero. This feature is similar to the OC2A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 16.6.4 Phase correct PWM mode The phase correct PWM mode (WGM22:0 = 1 or 5) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is based on a dual-slope operation. The counter counts repeatedly from BOTTOM to TOP and then from TOP to BOTTOM. TOP is defined as 0xFF when WGM22:0 = 1, and OCR2A when MGM22:0 = 5. In noninverting Compare Output mode, the Output Compare (OC2x) is cleared on the compare match between TCNT2 and OCR2x while upcounting, and set on the compare match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. In phase correct PWM mode the counter is incremented until the counter value matches TOP. When the counter reaches TOP, it changes the count direction. The TCNT2 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 16-7. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2x and TCNT2. Figure 16-7. Phase correct PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches BOTTOM. The Interrupt Flag can be used to generate an interrupt each time the counter reaches the BOTTOM value. In phase correct PWM mode, the compare unit allows generation of PWM waveforms on the OC2x pin. Setting the COM2x1:0 bits to two will produce a non-inverted PWM. An inverted PWM TOVn Interrupt Flag Set OCnx Interrupt Flag Set 1 2 3 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx update154 7593L–AVR–09/12 AT90USB64/128 output can be generated by setting the COM2x1:0 to three. TOP is defined as 0xFF when WGM2:0 = 3, and OCR2A when MGM2:0 = 7 (see Table 16-3 on page 157). The actual OC2x value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by clearing (or setting) the OC2x Register at the compare match between OCR2x and TCNT2 when the counter increments, and setting (or clearing) the OC2x Register at compare match between OCR2x and TCNT2 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2A Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR2A is set equal to BOTTOM, the output will be continuously low and if set equal to MAX the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. At the very start of period 2 in Figure 16-7 on page 153 OCnx has a transition from high to low even though there is no Compare Match. The point of this transition is to guarantee symmetry around BOTTOM. There are two cases that give a transition without Compare Match. • OCR2A changes its value from MAX, like in Figure 16-7 on page 153. When the OCR2A value is MAX the OCn pin value is the same as the result of a down-counting compare match. To ensure symmetry around BOTTOM the OCn value at MAX must correspond to the result of an up-counting Compare Match • The timer starts counting from a value higher than the one in OCR2A, and for that reason misses the Compare Match and hence the OCn change that would have happened on the way up 16.7 Timer/Counter timing diagrams The following figures show the Timer/Counter in synchronous mode, and the timer clock (clkT2) is therefore shown as a clock enable signal. In asynchronous mode, clkI/O should be replaced by the Timer/Counter Oscillator clock. The figures include information on when Interrupt Flags are set. Figure 16-8 contains timing data for basic Timer/Counter operation. The figure shows the count sequence close to the MAX value in all modes other than phase correct PWM mode. Figure 16-8. Timer/Counter timing diagram, no prescaling. f OCnxPCPWM f clk_I/O N ⋅ 510 = ------------------ clkTn (clkI/O/1) TOVn clkI/O TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1155 7593L–AVR–09/12 AT90USB64/128 Figure 16-9 shows the same timing data, but with the prescaler enabled. Figure 16-9. Timer/Counter timing diagram, with prescaler (fclk_I/O/8). Figure 16-10 shows the setting of OCF2A in all modes except CTC mode. Figure 16-10. Timer/Counter timing diagram, setting of OCF2A, with prescaler (fclk_I/O/8). Figure 16-11 on page 156 shows the setting of OCF2A and the clearing of TCNT2 in CTC mode. TOVn TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn OCRnx value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8)156 7593L–AVR–09/12 AT90USB64/128 Figure 16-11. Timer/Counter timing diagram, clear timer on compare match mode, with prescaler (fclk_I/O/8). 16.8 8-bit Timer/Counter register description 16.8.1 TCCR2A – Timer/Counter Control Register A • Bits 7:6 – COM2A1:0: Compare Match Output A mode These bits control the Output Compare pin (OC2A) behavior. If one or both of the COM2A1:0 bits are set, the OC2A output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC2A pin must be set in order to enable the output driver. When OC2A is connected to the pin, the function of the COM2A1:0 bits depends on the WGM22:0 bit setting. Table 16-1 shows the COM2A1:0 bit functionality when the WGM22:0 bits are set to a normal or CTC mode (non-PWM). OCFnx OCRnx TCNTn (CTC) TOP TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) Bit 7 6 5 4 3 2 1 0 COM2A1 COM2A0 COM2B1 COM2B0 – – WGM21 WGM20 TCCR2A Read/write R/W R/W R/W R/W R R R/W R/W Initial value 0 0 0 0 0 0 0 0 Table 16-1. Compare output mode, non-PWM mode. COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected 0 1 Toggle OC2A on Compare Match 1 0 Clear OC2A on Compare Match 1 1 Set OC2A on Compare Match157 7593L–AVR–09/12 AT90USB64/128 Table 16-2 shows the COM2A1:0 bit functionality when the WGM21:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Fast PWM mode” on page 151 for more details. Table 16-3 shows the COM2A1:0 bit functionality when the WGM22:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 153 for more details. • Bits 5:4 – COM2B1:0: Compare Match Output B mode These bits control the Output Compare pin (OC2B) behavior. If one or both of the COM2B1:0 bits are set, the OC2B output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC2B pin must be set in order to enable the output driver. When OC2B is connected to the pin, the function of the COM2B1:0 bits depends on the WGM22:0 bit setting. Table 16-4 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to a normal or CTC mode (non-PWM). Table 16-2. Compare Output mode, fast PWM mode (1). COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected 0 1 WGM22 = 0: Normal Port Operation, OC0A Disconnected. WGM22 = 1: Toggle OC2A on Compare Match. 1 0 Clear OC2A on Compare Match, set OC2A at TOP 1 1 Set OC2A on Compare Match, clear OC2A at TOP Table 16-3. Compare Output mode, phase correct PWM mode (1). COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected 0 1 WGM22 = 0: Normal Port Operation, OC2A Disconnected. WGM22 = 1: Toggle OC2A on Compare Match. 1 0 Clear OC2A on Compare Match when up-counting. Set OC2A on Compare Match when down-counting. 1 1 Set OC2A on Compare Match when up-counting. Clear OC2A on Compare Match when down-counting. Table 16-4. Compare Output mode, non-PWM mode. COM2B1 COM2B0 Description 0 0 Normal port operation, OC2B disconnected 0 1 Toggle OC2B on Compare Match 1 0 Clear OC2B on Compare Match 1 1 Set OC2B on Compare Match158 7593L–AVR–09/12 AT90USB64/128 Table 16-5 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Fast PWM mode” on page 151 for more details. Table 16-6 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 153 for more details. • Bits 3, 2 – Res: Reserved bits These bits are reserved bits in the Atmel AT90USB64/128 and will always read as zero. • Bits 1:0 – WGM21:0: Waveform Generation mode Combined with the WGM22 bit found in the TCCR2B Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 16-7. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes (see “Modes of operation” on page 150). Table 16-5. Compare Output mode, fast PWM mode (1). COM2B1 COM2B0 Description 0 0 Normal port operation, OC2B disconnected. 0 1 Reserved 1 0 Clear OC2B on Compare Match, set OC2B at TOP 1 1 Set OC2B on Compare Match, clear OC2B at TOP Table 16-6. Compare Output mode, phase correct PWM mode (1). COM2B1 COM2B0 Description 0 0 Normal port operation, OC2B disconnected 0 1 Reserved 1 0 Clear OC2B on Compare Match when up-counting. Set OC2B on Compare Match when down-counting 1 1 Set OC2B on Compare Match when up-counting. Clear OC2B on Compare Match when down-counting Table 16-7. Waveform Generation mode bit description. Mode WGM2 WGM1 WGM0 Timer/Counter mode of operation TOP Update of OCRx at TOV flag set on (1)(2) 0 0 0 0 Normal 0xFF Immediate MAX 1 0 0 1 PWM, phase correct 0xFF TOP BOTTOM 2 0 1 0 CTC OCRA Immediate MAX 3 0 1 1 Fast PWM 0xFF TOP MAX 4 1 0 0 Reserved – – –159 7593L–AVR–09/12 AT90USB64/128 Notes: 1. MAX= 0xFF 2. BOTTOM= 0x00 16.8.2 TCCR2B – Timer/Counter Control Register B • Bit 7 – FOC2A: Force Output Compare A The FOC2A bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2A bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC2A output is changed according to its COM2A1:0 bits setting. Note that the FOC2A bit is implemented as a strobe. Therefore it is the value present in the COM2A1:0 bits that determines the effect of the forced compare. A FOC2A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2A as TOP. The FOC2A bit is always read as zero. • Bit 6 – FOC2B: Force Output Compare B The FOC2B bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2B bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC2B output is changed according to its COM2B1:0 bits setting. Note that the FOC2B bit is implemented as a strobe. Therefore it is the value present in the COM2B1:0 bits that determines the effect of the forced compare. A FOC2B strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2B as TOP. The FOC2B bit is always read as zero. • Bits 5:4 – Res: Reserved bits These bits are reserved bits in the AT90USB64/128 and will always read as zero. • Bit 3 – WGM22: Waveform Generation mode See the description in the “TCCR2A – Timer/Counter Control Register A” on page 156. 5 1 0 1 PWM, phase correct OCRA TOP BOTTOM 6 1 1 0 Reserved – – – 7 1 1 1 Fast PWM OCRA TOP TOP Table 16-7. Waveform Generation mode bit description. (Continued) Mode WGM2 WGM1 WGM0 Timer/Counter mode of operation TOP Update of OCRx at TOV flag set on (1)(2) Bit 7 6 5 4 3 2 1 0 FOC2A FOC2B – – WGM22 CS22 CS21 CS20 TCCR2B Read/write W W R R R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0160 7593L–AVR–09/12 AT90USB64/128 • Bit 2:0 – CS22:0: Clock Select The three Clock Select bits select the clock source to be used by the Timer/Counter, see Table 16-8. 16.8.3 TCNT2 – Timer/Counter Register The Timer/Counter Register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the Compare Match on the following timer clock. Modifying the counter (TCNT2) while the counter is running, introduces a risk of missing a Compare Match between TCNT2 and the OCR2x Registers. 16.8.4 OCR2A – Output Compare Register A The Output Compare Register A contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2A pin. 16.8.5 OCR2B – Output Compare Register B The Output Compare Register B contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2B pin. Table 16-8. Clock Select bit description. CS22 CS21 CS20 Description 0 0 0 No clock source (Timer/Counter stopped) 0 0 1 clkT2S/(no prescaling) 0 1 0 clkT2S/8 (from prescaler) 0 1 1 clkT2S/32 (from prescaler) 1 0 0 clkT2S/64 (from prescaler) 1 0 1 clkT2S/128 (from prescaler) 1 1 0 clkT2S/256 (from prescaler) 1 1 1 clkT2S/1024 (from prescaler) Bit 7 6 5 4 3 2 1 0 TCNT2[7:0] TCNT2 Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR2A[7:0] OCR2A Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 OCR2B[7:0] OCR2B Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0161 7593L–AVR–09/12 AT90USB64/128 16.9 Asynchronous operation of the Timer/Counter 16.9.1 ASSR – Asynchronous Status Register • Bit 6 – EXCLK: Enable External Clock Input When EXCLK is written to one, and asynchronous clock is selected, the external clock input buffer is enabled and an external clock can be input on Timer Oscillator 1 (TOSC1) pin instead of a 32 kHz crystal. Writing to EXCLK should be done before asynchronous operation is selected. Note that the crystal Oscillator will only run when this bit is zero. • Bit 5 – AS2: Asynchronous Timer/Counter2 When AS2 is written to zero, Timer/Counter2 is clocked from the I/O clock, clkI/O. When AS2 is written to one, Timer/Counter2 is clocked from a crystal Oscillator connected to the Timer Oscillator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of TCNT2, OCR2A, OCR2B, TCCR2A and TCCR2B might be corrupted. • Bit 4 – TCN2UB: Timer/Counter2 Update Busy When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set. When TCNT2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value. • Bit 3 – OCR2AUB: Output Compare Register2 Update Busy When Timer/Counter2 operates asynchronously and OCR2A is written, this bit becomes set. When OCR2A has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2A is ready to be updated with a new value. • Bit 2 – OCR2BUB: Output Compare Register2 Update Busy When Timer/Counter2 operates asynchronously and OCR2B is written, this bit becomes set. When OCR2B has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2B is ready to be updated with a new value. • Bit 1 – TCR2AUB: Timer/Counter Control Register2 Update Busy When Timer/Counter2 operates asynchronously and TCCR2A is written, this bit becomes set. When TCCR2A has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2A is ready to be updated with a new value. • Bit 0 – TCR2BUB: Timer/Counter Control Register2 Update Busy When Timer/Counter2 operates asynchronously and TCCR2B is written, this bit becomes set. When TCCR2B has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2B is ready to be updated with a new value. If a write is performed to any of the five Timer/Counter2 Registers while its update busy flag is set, the updated value might get corrupted and cause an unintentional interrupt to occur. Bit 7 6 5 4 3 2 1 0 – EXCLK AS2 TCN2UB OCR2AUB OCR2BUB TCR2AUB TCR2BUB ASSR Read/write R R/W R/W R R R R R Initial value 0 0 0 0 0 0 0 0162 7593L–AVR–09/12 AT90USB64/128 The mechanisms for reading TCNT2, OCR2A, OCR2B, TCCR2A and TCCR2B are different. When reading TCNT2, the actual timer value is read. When reading OCR2A, OCR2B, TCCR2A and TCCR2B the value in the temporary storage register is read. 16.9.2 Asynchronous operation of Timer/Counter2 When Timer/Counter2 operates asynchronously, some considerations must be taken. • Warning: When switching between asynchronous and synchronous clocking of Timer/Counter2, the Timer Registers TCNT2, OCR2x, and TCCR2x might be corrupted. A safe procedure for switching clock source is: a. Disable the Timer/Counter2 interrupts by clearing OCIE2x and TOIE2. b. Select clock source by setting AS2 as appropriate. c. Write new values to TCNT2, OCR2x, and TCCR2x. d. To switch to asynchronous operation: Wait for TCN2UB, OCR2xUB, and TCR2xUB. e. Clear the Timer/Counter2 Interrupt Flags. f. Enable interrupts, if needed. • The CPU main clock frequency must be more than four times the Oscillator frequency • When writing to one of the registers TCNT2, OCR2x, or TCCR2x, the value is transferred to a temporary register, and latched after two positive edges on TOSC1. The user should not write a new value before the contents of the temporary register have been transferred to its destination. Each of the five mentioned registers have their individual temporary register, which means that, for example, writing to TCNT2 does not disturb an OCR2x write in progress. To detect that a transfer to the destination register has taken place, the Asynchronous Status Register – ASSR has been implemented • When entering Power-save or ADC Noise Reduction mode after having written to TCNT2, OCR2x, or TCCR2x, the user must wait until the written register has been updated if Timer/Counter2 is used to wake up the device. Otherwise, the MCU will enter sleep mode before the changes are effective. This is particularly important if any of the Output Compare2 interrupt is used to wake up the device, since the Output Compare function is disabled during writing to OCR2x or TCNT2. If the write cycle is not finished, and the MCU enters sleep mode before the corresponding OCR2xUB bit returns to zero, the device will never receive a compare match interrupt, and the MCU will not wake up • If Timer/Counter2 is used to wake the device up from Power-save or ADC Noise Reduction mode, precautions must be taken if the user wants to re-enter one of these modes: The interrupt logic needs one TOSC1 cycle to be reset. If the time between wake-up and reentering sleep mode is less than one TOSC1 cycle, the interrupt will not occur, and the device will fail to wake up. If the user is in doubt whether the time before re-entering Powersave or ADC Noise Reduction mode is sufficient, the following algorithm can be used to ensure that one TOSC1 cycle has elapsed: a. Write a value to TCCR2x, TCNT2, or OCR2x. b. Wait until the corresponding Update Busy Flag in ASSR returns to zero. c. Enter Power-save or ADC Noise Reduction mode. • When the asynchronous operation is selected, the 32.768kHz Oscillator for Timer/Counter2 is always running, except in Power-down and Standby modes. After a Power-up Reset or wake-up from Power-down or Standby mode, the user should be aware of the fact that this Oscillator might take as long as one second to stabilize. The user is advised to wait for at least one second before using Timer/Counter2 after power-up or wake-up from Power-down or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after 163 7593L–AVR–09/12 AT90USB64/128 a wake-up from Power-down or Standby mode due to unstable clock signal upon start-up, no matter whether the Oscillator is in use or a clock signal is applied to the TOSC1 pin • Description of wake up from Power-save or ADC Noise Reduction mode when the timer is clocked asynchronously: When the interrupt condition is met, the wake up process is started on the following cycle of the timer clock, that is, the timer is always advanced by at least one before the processor can read the counter value. After wake-up, the MCU is halted for four cycles, it executes the interrupt routine, and resumes execution from the instruction following SLEEP • Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect result. Since TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be done through a register synchronized to the internal I/O clock domain. Synchronization takes place for every rising TOSC1 edge. When waking up from Power-save mode, and the I/O clock (clkI/O) again becomes active, TCNT2 will read as the previous value (before entering sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after waking up from Power-save mode is essentially unpredictable, as it depends on the wake-up time. The recommended procedure for reading TCNT2 is thus as follows: a. Write any value to either of the registers OCR2x or TCCR2x. b. Wait for the corresponding Update Busy Flag to be cleared. c. Read TCNT2. • During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous timer takes 3 processor cycles plus one timer cycle. The timer is therefore advanced by at least one before the processor can read the timer value causing the setting of the Interrupt Flag. The Output Compare pin is changed on the timer clock and is not synchronized to the processor clock 16.9.3 TIMSK2 – Timer/Counter2 Interrupt Mask Register • Bit 2 – OCIE2B: Timer/Counter2 Output Compare Match B Interrupt Enable When the OCIE2B bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match B interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, that is, when the OCF2B bit is set in the Timer/Counter2 Interrupt Flag Register – TIFR2. • Bit 1 – OCIE2A: Timer/Counter2 Output Compare Match A Interrupt Enable When the OCIE2A bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match A interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, that is, when the OCF2A bit is set in the Timer/Counter2 Interrupt Flag Register – TIFR2. • Bit 0 – TOIE2: Timer/Counter2 Overflow Interrupt Enable When the TOIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter2 occurs, that is, when the TOV2 bit is set in the Timer/Counter2 Interrupt Flag Register – TIFR2. Bit 7 6 5 4 3 2 1 0 – – – – – OCIE2B OCIE2A TOIE2 TIMSK2 Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0164 7593L–AVR–09/12 AT90USB64/128 16.9.4 TIFR2 – Timer/Counter2 Interrupt Flag Register • Bit 2 – OCF2B: Output Compare Flag 2 B The OCF2B bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2B – Output Compare Register2. OCF2B is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF2B is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2B (Timer/Counter2 Compare match Interrupt Enable), and OCF2B are set (one), the Timer/Counter2 Compare match Interrupt is executed. • Bit 1 – OCF2A: Output Compare Flag 2 A The OCF2A bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2A – Output Compare Register2. OCF2A is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF2A is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2A (Timer/Counter2 Compare match Interrupt Enable), and OCF2A are set (one), the Timer/Counter2 Compare match Interrupt is executed. • Bit 0 – TOV2: Timer/Counter2 Overflow Flag The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV2 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE2A (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter2 changes counting direction at 0x00. 16.10 Timer/Counter prescaler Figure 16-12. Prescaler for Timer/Counter2. Bit 7 6 5 4 3 2 1 0 – – – – – OCF2B OCF2A TOV2 TIFR2 Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 10-BIT T/C PRESCALER TIMER/COUNTER2 CLOCK SOURCE clkI/O clkT2S TOSC1 AS2 CS20 CS21 CS22 clkT2S/8 clkT2S/64 clkT2S/128 clkT2S/1024 clkT2S/256 clkT2S/32 0 PSRASY Clear clkT2165 7593L–AVR–09/12 AT90USB64/128 The clock source for Timer/Counter2 is named clkT2S. clkT2S is by default connected to the main system I/O clock clkIO. By setting the AS2 bit in ASSR, Timer/Counter2 is asynchronously clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real Time Counter (RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from Port C. A crystal can then be connected between the TOSC1 and TOSC2 pins to serve as an independent clock source for Timer/Counter2. The Oscillator is optimized for use with a 32.768kHz crystal. Applying an external clock source to TOSC1 is not recommended. For Timer/Counter2, the possible prescaled selections are: clkT2S/8, clkT2S/32, clkT2S/64, clkT2S/128, clkT2S/256, and clkT2S/1024. Additionally, clkT2S as well as 0 (stop) may be selected. Setting the PSRASY bit in GTCCR resets the prescaler. This allows the user to operate with a predictable prescaler. 16.10.1 GTCCR – General Timer/Counter Control Register • Bit 1 – PSRASY: Prescaler Reset Timer/Counter2 When this bit is one, the Timer/Counter2 prescaler will be reset. This bit is normally cleared immediately by hardware. If the bit is written when Timer/Counter2 is operating in asynchronous mode, the bit will remain one until the prescaler has been reset. The bit will not be cleared by hardware if the TSM bit is set. Refer to the description of the Section “GTCCR – General Timer/Counter Control Register” on page 97 for a description of the Timer/Counter Synchronization mode. Bit 7 6 5 4 3 2 1 0 TSM – – – – – PSRASY PSRSY NC GTCCR Read/write R/W R R R R R R/W R/W Initial value 0 0 0 0 0 0 0 0166 7593L–AVR–09/12 AT90USB64/128 17. Output Compare Modulator (OCM1C0A) 17.1 Overview The Output Compare Modulator (OCM) allows generation of waveforms modulated with a carrier frequency. The modulator uses the outputs from the Output Compare Unit C of the 16-bit Timer/Counter1 and the Output Compare Unit of the 8-bit Timer/Counter0. For more details about these Timer/Counters see “Timer/Counter0, Timer/Counter1, and Timer/Counter3 prescalers” on page 96 and “8-bit Timer/Counter2 with PWM and asynchronous operation” on page 145. Figure 17-1. Output Compare Modulator, block diagram. When the modulator is enabled, the two output compare channels are modulated together as shown in the block diagram (Figure 17-1). 17.2 Description The Output Compare unit 1C and Output Compare unit 2 shares the PB7 port pin for output. The outputs of the Output Compare units (OC1C and OC0A) overrides the normal PORTB7 Register when one of them is enabled (that is, when COMnx1:0 is not equal to zero). When both OC1C and OC0A are enabled at the same time, the modulator is automatically enabled. The functional equivalent schematic of the modulator is shown on Figure 17-2. The schematic includes part of the Timer/Counter units and the port B pin 7 output driver circuit. Figure 17-2. Output Compare Modulator, schematic. OC1C Pin OC1C / OC0A / PB7 Timer/Counter 1 Timer/Counter 0 OC0A PORTB7 DDRB7 D Q D Q Pin COMA01 COMA00 DATABUS OC1C / OC0A/ PB7 COM1C1 COM1C0 Modulator 1 0 OC1C D Q OC0A D Q (From Waveform generator) (From Waveform generator) 0 1 Vcc167 7593L–AVR–09/12 AT90USB64/128 When the modulator is enabled the type of modulation (logical AND or OR) can be selected by the PORTB7 Register. Note that the DDRB7 controls the direction of the port independent of the COMnx1:0 bit setting. 17.2.1 Timing example Figure 17-3 illustrates the modulator in action. In this example the Timer/Counter1 is set to operate in fast PWM mode (non-inverted) and Timer/Counter0 uses CTC waveform mode with toggle Compare Output mode (COMnx1:0 = 1). Figure 17-3. Output Compare Modulator, timing diagram. In this example, Timer/Counter2 provides the carrier, while the modulating signal is generated by the Output Compare unit C of the Timer/Counter1. The resolution of the PWM signal (OC1C) is reduced by the modulation. The reduction factor is equal to the number of system clock cycles of one period of the carrier (OC0A). In this example the resolution is reduced by a factor of two. The reason for the reduction is illustrated in Figure 17-3 at the second and third period of the PB7 output when PORTB7 equals zero. The period 2 high time is one cycle longer than the period 3 high time, but the result on the PB7 output is equal in both periods. 1 2 OC0A (CTC mode) OC1C (FPWM mode) PB7 (PORTB7 = 0) PB7 (PORTB7 = 1) (Period) 3 clk I/O168 7593L–AVR–09/12 AT90USB64/128 18. SPI – Serial Peripheral Interface The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the Atmel AT90USB64/128 and peripheral devices or between several AVR devices. The AT90USB64/128 SPI includes the following features: • Full-duplex, three-wire synchronous data transfer • Master or slave operation • LSB first or MSB first data transfer • Seven programmable bit rates • End of transmission interrupt flag • Write collision flag protection • Wake-up from Idle mode • Double speed (CK/2) Master SPI mode USART can also be used in Master SPI mode, see “USART in SPI mode” on page 202. The Power Reduction SPI bit, PRSPI, in “PRR0 – Power Reduction Register 0” on page 54 must be written to zero to enable SPI module. Figure 18-1. SPI block diagram (1). Note: 1. Refer to Figure 1-1 on page 3, and Table 11-6 on page 79 for SPI pin placement. The interconnection between Master and Slave CPUs with SPI is shown in Figure 18-2 on page 169. The system consists of two shift Registers, and a Master clock generator. The SPI Master initiates the communication cycle when pulling low the Slave Select SS pin of the desired Slave. SPI2X SPI2X DIVIDER /2/4/8/16/32/64/128169 7593L–AVR–09/12 AT90USB64/128 Master and Slave prepare the data to be sent in their respective shift Registers, and the Master generates the required clock pulses on the SCK line to interchange data. Data is always shifted from Master to Slave on the Master Out – Slave In, MOSI, line, and from Slave to Master on the Master In – Slave Out, MISO, line. After each data packet, the Master will synchronize the Slave by pulling high the Slave Select, SS, line. When configured as a Master, the SPI interface has no automatic control of the SS line. This must be handled by user software before communication can start. When this is done, writing a byte to the SPI Data Register starts the SPI clock generator, and the hardware shifts the eight bits into the Slave. After shifting one byte, the SPI clock generator stops, setting the end of Transmission Flag (SPIF). If the SPI Interrupt Enable bit (SPIE) in the SPCR Register is set, an interrupt is requested. The Master may continue to shift the next byte by writing it into SPDR, or signal the end of packet by pulling high the Slave Select, SS line. The last incoming byte will be kept in the Buffer Register for later use. When configured as a Slave, the SPI interface will remain sleeping with MISO tri-stated as long as the SS pin is driven high. In this state, software may update the contents of the SPI Data Register, SPDR, but the data will not be shifted out by incoming clock pulses on the SCK pin until the SS pin is driven low. As one byte has been completely shifted, the end of Transmission Flag, SPIF is set. If the SPI Interrupt Enable bit, SPIE, in the SPCR Register is set, an interrupt is requested. The Slave may continue to place new data to be sent into SPDR before reading the incoming data. The last incoming byte will be kept in the Buffer Register for later use. Figure 18-2. SPI Master-slave interconnection. The system is single buffered in the transmit direction and double buffered in the receive direction. This means that bytes to be transmitted cannot be written to the SPI Data Register before the entire shift cycle is completed. When receiving data, however, a received character must be read from the SPI Data Register before the next character has been completely shifted in. Otherwise, the first byte is lost. In SPI Slave mode, the control logic will sample the incoming signal of the SCK pin. To ensure correct sampling of the clock signal, the frequency of the SPI clock should never exceed fosc/4. When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden according to Table 18-1 on page 170. For more details on automatic port overrides, refer to “Alternate port functions” on page 76. SHIFT ENABLE170 7593L–AVR–09/12 AT90USB64/128 Note: 1. See “Alternate functions of Port B” on page 79 for a detailed description of how to define the direction of the user defined SPI pins. The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. For example, if MOSI is placed on pin PB5, replace DD_MOSI with DDB5 and DDR_SPI with DDRB. Table 18-1. SPI pin overrides (1). Pin Direction, master SPI Direction, slave SPI MOSI User defined Input MISO Input User defined SCK User defined Input SS User defined Input171 7593L–AVR–09/12 AT90USB64/128 Note: 1. See “About code examples” on page 10. Assembly code example (1) SPI_MasterInit: ; Set MOSI and SCK output, all others input ldi r17,(1<>8); UBRRLn = (unsigned char)baud; /* Enable receiver and transmitter */ UCSRnB = (1<> 1) & 0x01; return ((resh << 8) | resl); }188 7593L–AVR–09/12 AT90USB64/128 The Receive Complete (RXCn) Flag indicates if there are unread data present in the receive buffer. This flag is one when unread data exist in the receive buffer, and zero when the receive buffer is empty (that is, does not contain any unread data). If the Receiver is disabled (RXENn = 0), the receive buffer will be flushed and consequently the RXCn bit will become zero. When the Receive Complete Interrupt Enable (RXCIEn) in UCSRnB is set, the USART Receive Complete interrupt will be executed as long as the RXCn Flag is set (provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDRn in order to clear the RXCn Flag, otherwise a new interrupt will occur once the interrupt routine terminates. 19.6.4 Receiver error flags The USART Receiver has three error flags: Frame Error (FEn), Data OverRun (DORn) and Parity Error (UPEn). All can be accessed by reading UCSRnA. Common for the Error Flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the Error Flags, the UCSRnA must be read before the receive buffer (UDRn), since reading the UDRn I/O location changes the buffer read location. Another equality for the Error Flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRnA is written for upward compatibility of future USART implementations. None of the Error Flags can generate interrupts. The Frame Error (FEn) Flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FEn Flag is zero when the stop bit was correctly read (as one), and the FEn Flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FEn Flag is not affected by the setting of the USBSn bit in UCSRnC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. The Data OverRun (DORn) Flag indicates data loss due to a receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DORn Flag is set there was one or more serial frame lost between the frame last read from UDRn, and the next frame read from UDRn. For compatibility with future devices, always write this bit to zero when writing to UCSRnA. The DORn Flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (UPEn) Flag indicates that the next frame in the receive buffer had a Parity Error when received. If Parity Check is not enabled the UPEn bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. For more details see “Parity bit calculation” on page 181 and “Parity Checker” on page 188. 19.6.5 Parity Checker The Parity Checker is active when the high USART Parity mode (UPMn1) bit is set. Type of Parity Check to be performed (odd or even) is selected by the UPMn0 bit. When enabled, the Parity Checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error (UPEn) Flag can then be read by software to check if the frame had a Parity Error.189 7593L–AVR–09/12 AT90USB64/128 The UPEn bit is set if the next character that can be read from the receive buffer had a Parity Error when received and the Parity Checking was enabled at that point (UPMn1 = 1). This bit is valid until the receive buffer (UDRn) is read. 19.6.6 Disabling the Receiver In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing receptions will therefore be lost. When disabled (that is, the RXENn is set to zero) the Receiver will no longer override the normal function of the RxDn port pin. The Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in the buffer will be lost 19.6.7 Flushing the receive buffer The receiver buffer FIFO will be flushed when the Receiver is disabled, that is, the buffer will be emptied of its contents. Unread data will be lost. If the buffer has to be flushed during normal operation, due to for instance an error condition, read the UDRn I/O location until the RXCn Flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See “About code examples” on page 10. 19.7 Asynchronous data reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxDn pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the Receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. 19.7.1 Asynchronous clock recovery The clock recovery logic synchronizes internal clock to the incoming serial frames. Figure 19-5 on page 190 illustrates the sampling process of the start bit of an incoming frame. The sample rate is 16 times the baud rate for Normal mode, and eight times the baud rate for Double Speed mode. The horizontal arrows illustrate the synchronization variation due to the sampling process. Note the larger time variation when using the Double Speed mode (U2Xn = 1) of operation. Samples denoted zero are samples done when the RxDn line is idle (that is, no communication activity). Assembly code example (1) USART_Flush: sbis UCSRnA, RXCn ret in r16, UDRn rjmp USART_Flush C code example (1) void USART_Flush( void ) { unsigned char dummy; while ( UCSRnA & (1< USBE=1 ID=1 Clock stopped FRZCLK=1 Macro off USBE=0 USBE=0 Host USBE=0 HW RESET USBE=1 ID=0 AT90USB647/1287 only AT90USB646/1286 forced mode247 7593L–AVR–09/12 AT90USB64/128 22.4.3 Interrupts Two interrupts vectors are assigned to USB interface. Figure 22-10. USB interrupt system. See Section 23.17, page 272 and Section 24.15, page 291 for more details on the Host and Device interrupts. USB general & OTG interrupt USB device interrupt USB host interrupt USB general interrupt vector Endpoint interrupt Pipe interrupt USB endpoint/pipe interrupt vector248 7593L–AVR–09/12 AT90USB64/128 Figure 22-11. USB general interrupt vector sources. IDTE USBCON.1 IDTI USBINT.1 VBUSTI USBINT.0 VBUSTE USBCON.0 STOI OTGINT.5 STOE OTGIEN.5 HNPERRI OTGINT.4 HNPERRE OTGIEN.4 ROLEEXI OTGINT.3 ROLEEXE OTGIEN.3 BCERRI OTGINT.2 BCERRE OTGIEN.2 VBERRI OTGINT.1 VBERRE OTGIEN.1 SRPI OTGINT.0 SRPE OTGIEN.0 USB general interrupt vector UPRSMI UDINT.6 UPRSME UDIEN.6 EORSMI UDINT.5 EORSME UDIEN.5 WAKEUPI UDINT.4 WAKEUPE UDIEN.4 EORSTI UDINT.3 EORSTE UDIEN.3 SOFI UDINT.2 SOFE UDIEN.2 SUSPI UDINT.0 SUSPE UDIEN.0 HWUPE UHIEN.6 HWUPI UHINT.6 HSOFI UHINT.5 HSOFE UHIEN.5 RXRSMI UHINT.4 RXRSME UHIEN.4 RSMEDI UHINT.3 RSMEDE UHIEN.3 RSTI UHINT.2 RSTE UHIEN.2 DDISCI UHINT.1 DDISCE UHIEN.1 DCONNI UHINT.0 DCONNE UHIEN.0 USB device interrupt USB host interrupt USB general interrupt vector Asynchronous interrupt source (allows the CPU to wake up from power down mode)249 7593L–AVR–09/12 AT90USB64/128 Figure 22-12. USB endpoint/pipe Interrupt vector sources. FLERRE UEIENX.7 OVERFI UESTAX.6 UNDERFI UESTAX.5 NAKINI UEINTX.6 NAKINE UEIENX.6 NAKOUTI UEINTX.4 TXSTPE UEIENX.4 RXSTPI UEINTX.3 RXSTPE UEIENX.3 RXOUTI UEINTX.2 RXOUTE UEIENX.2 STALLEDI UEINTX.1 STALLEDE UEIENX.1 EPINT UEINT.X Endpoint 0 Endpoint 1 Endpoint 2 Endpoint 3 Endpoint 4 Endpoint 5 Endpoint interrupt TXINI UEINTX.0 TXINE UEIENX.0 FLERRE UPIEN.7 UNDERFI UPSTAX.5 OVERFI UPSTAX.6 NAKEDI UPINTX.6 NAKEDE UPIEN.6 PERRI UPINTX.4 PERRE UPIEN.4 TXSTPI UPINTX.3 TXSTPE UPIEN.3 TXOUTI UPINTX.2 TXOUTE UPIEN.2 RXSTALLI UPINTX.1 RXSTALLE UPIEN.1 RXINI UPINTX.0 RXINE UPIEN.0 FLERRE UPIEN.X PIPE 0 PIPE 1 PIPE 2 PIPE 3 PIPE 4 PIPE 5 Pipe interrupt USB endpoint/pipe interrupt vector Endpoint 6 PIPE 6250 7593L–AVR–09/12 AT90USB64/128 Figure 22-13. USB general and OTG controller interrupt system. There are two kinds of interrupts: processing (that is, their generation are part of the normal processing) and exception (errors). Processing interrupts are generated when such events occur: • USB ID Pad change detection (insert, remove)(IDTI) • VBUS plug-in detection (insert, remove) (VBUSTI) • SRP detected(SRPI) • Role Exchanged(ROLEEXI) Exception Interrupts are generated with the following events: • Drop on VBus Detected(VBERRI) • Error during the B-Connection(BCERRI) • HNP Error(HNPERRI) • Time-out detected during Suspend mode(STOII) 22.5 Power modes 22.5.1 Idle mode In this mode, the CPU core is halted (CPU clock stopped). The Idle mode is taken wether the USB controller is running or not. The CPU “wakes up” on any USB interrupts. 22.5.2 Power down In this mode, the oscillator is stopped and halts all the clocks (CPU and peripherals). The USB controller “wakes up” when: • the WAKEUPI interrupt is triggered in the Peripheral mode (HOST cleared) IDTE USBCON.1 IDTI USBINT.1 VBUSTI USBINT.0 VBUSTE USBCON.0 STOI OTGINT.5 STOE OTGIEN.5 HNPERRI OTGINT.4 HNPERRE OTGIEN.4 ROLEEXI OTGINT.3 ROLEEXE OTGIEN.3 BCERRI OTGINT.2 BCERRE OTGIEN.2 VBERRI OTGINT.1 VBERRE OTGIEN.1 SRPI OTGINT.0 SRPE OTGIEN.0 USB general & OTG interrupt vector Asynchronous interrupt source (allows the CPU to wake up from power down mode251 7593L–AVR–09/12 AT90USB64/128 • the HWUPI interrupt is triggered in the Host mode (HOST set) • the IDTI interrupt is triggered • the VBUSTI interrupt is triggered 22.5.3 Freeze clock The firmware has the ability to reduce the power consumption by setting the FRZCLK bit, which freeze the clock of USB controller. When FRZCLK is set, it is still possible to access to the following registers: • USBCON, USBSTA, USBINT • UDCON (detach, ...) • UDINT • UDIEN • UHCON • UHINT • UHIEN Moreover, when FRZCLK is set, only the following interrupts may be triggered: • WAKEUPI • IDTI • VBUSTI • HWUPI 22.6 Speed control 22.6.1 Device mode When the USB interface is configured in device mode, the speed selection (Full Speed or Low Speed) depends on the UDP/UDM pull-up. The LSM bit in UDCON register allows to select an internal pull up on UDM (Low Speed mode) or UDP (Full Speed mode) data lines. Figure 22-14. Device mode speed selection. RPU DETACH UDCON.0 UDP UDM RPU LSM UDCON.2 UCAP USB regulator252 7593L–AVR–09/12 AT90USB64/128 22.6.2 Host mode When the USB interface is configured in host mode, internal Pull Down resistors are activated on both UDP UDM lines and the interface detects the type of connected device. 22.7 Memory management The controller does only support the following memory allocation management. The reservation of a Pipe or an Endpoint can only be made in the increasing order (Pipe/Endpoint 0 to the last Pipe/Endpoint). The firmware shall thus configure them in the same order. The reservation of a Pipe or an Endpoint “ki ” is done when its ALLOC bit is set. Then, the hardware allocates the memory and inserts it between the Pipe/Endpoints “ki-1” and “ki+1”. The “ki+1” Pipe/Endpoint memory “slides” up and its data is lost. Note that the “ki+2” and upper Pipe/Endpoint memory does not slide. Clearing a Pipe enable (PEN) or an Endpoint enable (EPEN) does not clear either its ALLOC bit, or its configuration (EPSIZE/PSIZE, EPBK/PBK). To free its memory, the firmware should clear ALLOC. Then, the “ki+1” Pipe/Endpoint memory automatically “slides” down. Note that the “ki+2” and upper Pipe/Endpoint memory does not slide. The following figure illustrates the allocation and reorganization of the USB memory in a typical example: Table 22-1. Allocation and reorganization USB memory flow. • First, Pipe/Endpoint 0 to Pipe/Endpoint 5 are configured, in the growing order. The memory of each is reserved in the DPRAM • Then, the Pipe/Endpoint 3 is disabled (EPEN=0), but its memory reservation is internally kept by the controller • Its ALLOC bit is cleared: the Pipe/Endpoint 4 “slides” down, but the Pipe/Endpoint 5 does not “slide” • Finally, if the firmware chooses to reconfigure the Pipe/Endpoint 3, with a bigger size. The controller reserved the memory after the endpoint 2 memory and automatically “slide” the Pipe/Endpoint 4. The Pipe/Endpoint 5 does not move and a memory conflict appear, in that Free memory 0 1 2 3 4 5 EPEN=1 ALLOC=1 Free memory 0 1 2 4 5 EPEN=0 (ALLOC=1) Free memory 0 1 2 4 5 Pipe/Endpoints activation Pipe/Endpoint Disable Free its memory (ALLOC=0) Free memory 0 1 2 3 (bigger size) 5 Pipe/Endpoint Activatation Lost memory 4 Conflict253 7593L–AVR–09/12 AT90USB64/128 both Pipe/Endpoint 4 and 5 use a common area. The data of those endpoints are potentially lost Note that: • the data of Pipe/Endpoint 0 are never lost whatever the activation or deactivation of the higher Pipe/Endpoint. Its data is lost if it is deactivated • Deactivate and reactivate the same Pipe/Endpoint with the same parameters does not lead to a “slide” of the higher endpoints. For those endpoints, the data are preserved • CFGOK is set by hardware even in the case where there is a “conflict” in the memory allocation 22.8 PAD suspend The next figures illustrates the pad behaviour: • In the “idle” mode, the pad is put in low power consumption mode • In the “active” mode, the pad is working Figure 22-15. Pad behaviour. The SUSPI flag indicated that a suspend state has been detected on the USB bus. This flag automatically put the USB pad in Idle. The detection of a non-idle event sets the WAKEUPI flag and wakes-up the USB pad. Moreover, the pad can also be put in the “idle” mode if the DETACH bit is set. It come back in the active mode when the DETACH bit is cleared. Idle mode Active mode USBE=1 & DETACH=0 & suspend USBE=0 | DETACH=1 | suspend SUSPI Suspend detected = USB pad power down Clear suspend by software Resume = USB pad wake-up WAKEUPI Clear resume by software PAD status Active Power Down Active254 7593L–AVR–09/12 AT90USB64/128 22.9 OTG timers customizing It is possible to refine some OTG timers thanks to the OTGTCON register that contains the PAGE bits to select the timer and the VALUE bits to adjust the value. User should refer to lastest releases of the OTG specification to select compliant timings. • PAGE=00b: AWaitVrise time-out. [OTG]. In Host mode, once VBUSREQ has been set to “1”, if no VBUS is detected on VBUS pin after this AWaitVrise delay then the VBERRI error flag is set. – VALUE=00bTime-out is set to 20ms – VALUE=01bTime-out is set to 50ms – VALUE=10bTime-out is set to 70ms – VALUE=11bTime-out is set to 100ms • PAGE=01b: VbBusPulsing. [OTG]. In Device mode, this delay corresponds to the pulse duration on Vbus during a SRP. – VALUE=00bTime-out is set to 15ms – VALUE=01bTime-out is set to 23ms – VALUE=10bTime-out is set to 31ms – VALUE=11bTime-out is set to 40ms • PAGE=10b: PdTmOutCnt. [OTG]. In Device mode, when a SRP has been requested to be sent by the firmware, this delay is waited by the hardware after VBUS has gone below the “session_valid” threshold voltage and before initiating the first pulse. This delay should be considered as an approximation of USB lines discharge (pull-down resistors vs. line capacitance) in order to wait that VBUS has gone below the “b_session_end” threshold voltae, as defined in the OTG specification. – VALUE=00bTime-out is set to 93ms – VALUE=01bTime-out is set to 105ms – VALUE=10bTime-out is set to 118ms – VALUE=11bTime-out is set to 131ms • PAGE=11b: SRPDetTmOut. [OTG]. In Host mode, this delay is the minimum pulse duration required to detect and accept a valid SRP from a Device. – VALUE=00bTime-out is set to 1µs – VALUE=01bTime-out is set to 100µs – VALUE=10bTime-out is set to 1ms – VALUE=11bTime-out is set to 11ms255 7593L–AVR–09/12 AT90USB64/128 22.10 Plug-in detection The USB connection is detected by the VBUS pad, thanks to the following architecture: Figure 22-16. Plug-in detection input block diagram. The control logic of the VBUS pad outputs a signal regarding the VBUS voltage level: • The “Session_valid” signal is active high when the voltage on the VBUS pad is higher or equal to 1.4V. If lower than 1.4V, the signal is not active • The “Vbus_valid” signal is active high when the voltage on the VBUS pad is higher or equal to 4.4V. If lower than 4.4V, the signal is not active • The VBUS status bit is set when VBUS is greater than “Vbus_valid”. The VBUS status bit is cleared when VBUS falls below “Session_valid” (hysteresis behavior) • The VBUSTI flag is set each time the VBUS bit state changes 22.10.1 Peripheral mode The USB peripheral cannot attach to the bus while VBUS bit is not set. 22.10.2 Host mode The Host must use the UVCON pin to drive an external power switch or regulator that powers the Vbus line. The UVCON pin is automatically asserted and set high by hardware when UVCONE and VBUSREQ bits are set by firmware. If a device connects (pull-up on DP or DM) within 300ms of Vbus delivery, the DCONNI flag will rise. But, once VBUSREQ bit has been set, if no peripheral connection is detected within 300ms, the BCERRI flag (and interrupt) will rise and Vbus delivery will be stopped (UVCON cleared). If that behavior represents a limitation for the Host application, the following work-around may be used : 1. UVCONE and VBUSREQ must be cleared. 2. VBUSHWC must be set (to disable hardware control of UVCON pin). 3. PORTE,7 pin (alternate function of UVCON pin) must be set by firmware. 4. a device connection will be detected thanks to the SRPI flag (that may usually be used to detect a DP/DM pulse sent by an OTG B-Device that requests a new session). VBUSTI USBINT.0 VBUS VBUS USBSTA.0 VSS VDD Pad logic Logic Session_valid RPU RPU VBus_pulsing VBus_discharge Vbus_valid256 7593L–AVR–09/12 AT90USB64/128 22.11 ID detection The ID pin transition is detected thanks to the following architecture: Figure 22-17. ID detection input block diagram. The ID pin can be used to detect the USB mode (Peripheral or Host) or software selected. This allows the UID pin to be used has general purpose I/O even when USB interface is enable. When the UID pin is selected, by default, (no A-plug or B-plug), the macro is in the Peripheral mode (internal pull-up). The IDTI interrupt is triggered when a A-plug (Host) is plugged or unplugged. The interrupt is not triggered when a B-plug (Periph) is plugged or unplugged. ID detection is independent of USB global interface enable. 22.12 Registers description 22.12.1 USB general registers • 7 – UIMOD: USB Mode bit This bit has no effect when the UIDE bit is set (external UID pin activated). Set to enable the USB device mode. Clear to enable the USB host mode • 6 – UIDE: UID pin Enable Set to enable the USB mode selection (peripheral/host) through the UID pin. Clear to enable the USB mode selection (peripheral/host) with UIMOD bit register. UIDE should be modified only when the USB interface is disabled (USBE bit cleared). • 5 – Reserved The value read from this bit is always 0. Do not set this bit. • 4 – UVCONE: UVCON pin Enable Set to enable the UVCON pin control. Clear to disable the UVCON pin control. This bit should be set only when the USB interface is enable. RPU UIMOD UHWCON.7 UID ID USBSTA.1 Internal pull up VDD UIDE UHWCON.6 1 0 Bit 7 6 5 4 3 2 1 0 UIMOD UIDE UVCONE UVREGE UHWCON Read/write R/W R/W R R/W R R R R/W Initial value 1 0 0 0 0 0 0 0257 7593L–AVR–09/12 AT90USB64/128 • 3-1 – Reserved The value read from these bits is always 0. Do not set these bits. • 0 – UVREGE: USB pad regulator Enable Set to enable the USB pad regulator. Clear to disable the USB pad regulator. • 7 – USBE: USB macro Enable bit Set to enable the USB controller. Clear to disable and reset the USB controller, to disable the USB transceiver and to disable the USB controller clock inputs. • 6 – HOST: HOST bit Set to enable the Host mode. Clear to enable the device mode. • 5 – FRZCLK: Freeze USB Clock bit Set to disable the clock inputs (the ”Resume Detection” is still active). This reduces the power consumption. Clear to enable the clock inputs. • 4 – OTGPADE: OTG Pad Enable Set to enable the OTG pad. Clear to disable the OTG pad. The OTG pad is actually the VBUS pad. Note that this bit can be set/cleared even if USBE=0. That allows the VBUS detection even if the USB macro is disabled. This pad must be enabled in both Host and Device modes in order to allow USB operation (attaching, transmitting...). • 3-2 – Reserved The value read from these bits is always 0. Do not set these bits. • 1 – IDTE: ID Transition Interrupt Enable bit Set this bit to enable the ID Transition interrupt generation. Clear this bit to disable the ID Transition interrupt generation. • 0 – VBUSTE: VBUS Transition Interrupt Enable bit Set this bit to enable the VBUS Transition interrupt generation. Clear this bit to disable the VBUS Transition interrupt generation. • 7-4 - Reserved The value read from these bits is always 0. Do not set these bits. Bit 7 6 5 4 3 2 1 0 USBE HOST FRZCLK OTGPADE - - IDTE VBUSTE USBCON Read/write R/W R/W R/W R/W R R R/W R/W Initial value 0 0 1 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - - - SPEED ID VBUS USBSTA Read/write R R R R R R R R Initial value 0 0 0 0 1 0 1 0258 7593L–AVR–09/12 AT90USB64/128 • 3 – SPEED: Speed Status Flag This should be read only when the USB controller operates in host mode, in device mode the value read from this bit is undeterminated. Set by hardware when the controller is in FULL-SPEED mode. Cleared by hardware when the controller is in LOW-SPEED mode. • 2 – Reserved The value read from this bit is always 0. Do not set this bit. • 1 – ID: IUD pin flag The value read from this bit indicates the state of the UID pin. • 0 – VBUS: VBus flag The value read from this bit indicates the state of the VBUS pin. This bit can be used in device mode to monitor the USB bus connection state of the application. See Section 22.10, page 255 for more details. 7-2 - Reserved The value read from these bits is always 0. Do not set these bits. 1 – IDTI: D Transition Interrupt flag Set by hardware when a transition (high to low, low to high) has been detected on the UID pin. Shall be cleared by software. • 0 – VBUSTI: IVBUS Transition Interrupt flag Set by hardware when a transition (high to low, low to high) has been detected on the VBUS pad. Shall be cleared by software. • 7-6 - Reserved The value read from these bits is always 0. Do not set these bits. • 5 – HNPREQ: HNP Request bit Set to initiate the HNP when the controller is in the Device mode (B). Set to accept the HNP when the controller is in the Host mode (A). Clear otherwise. Bit 7 6 5 4 3 2 1 0 - - - - - - IDTI VBUSTI USBINT Read/write R R R R R R R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - HNPREQ SRPREQ SRPSEL VBUSHWC VBUSREQ VBUSRQC OTGCON Read/write R R R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0259 7593L–AVR–09/12 AT90USB64/128 • 4 – SRPREQ: SRP Request bit Set to initiate the SRP when the controller is in Device mode. Cleared by hardware when the controller is initiating a SRP. • 3 – SRPSEL: SRP Selection bit Set to choose VBUS pulsing as SRP method. Clear to choose data line pulsing as SRP method. • 2 – VBUSHWC: VBus Hardware Control bit Set to disable the hardware control over the UVCON pin. Clear to enable the hardware control over the UVCON pin. See for more details • 1 – VBUSREQ: VBUS Request bit Set to assert the UVCON pin in order to enable the VBUS power supply generation. This bit shall be used when the controller is in the Host mode. Cleared by hardware when VBUSRQC is set. • 0 – VBUSRQC: VBUS Request Clear bit Set to deassert the UVCON pin in order to enable the VBUS power supply generation. This bit shall be used when the controller is in the Host mode. Cleared by hardware immediately after the set. • 7 – Reserved This bit is reserved and always set. • 6-5 – PAGE: Timer page access bit Set/clear to access a special timer register. See Section 22.9, page 254 for more details. • 4-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 1-0 – VALUE: Value bit Set to initialize the new value of the timer. See Section 22.9, page 254 for more details. Bit 7 6 5 4 3 2 1 0 - PAGE - - - VALUE OTGTCON Read/write R R/W R/W R R R/W R/W R/W Initial value 1 0 0 0 0 0 0 0260 7593L–AVR–09/12 AT90USB64/128 • 7-6 - Reserved The value read from these bits is always 0. Do not set these bits. • 5 – STOE: Suspend Time-out Error Interrupt Enable bit Set to enable the STOI interrupt. Clear to disable the STOI interrupt. • 4 – HNPERRE: HNP Error Interrupt Enable bit Set to enable the HNPERRI interrupt. Clear to disable the HNPERRI interrupt. • 3 – ROLEEXE: Role Exchange Interrupt Enable bit Set to enable the ROLEEXI interrupt. Clear to disable the ROLEEXI interrupt. • 2 – BCERRE: B-Connection Error Interrupt Enable bit Set to enable the BCERRI interrupt. Clear to disable the BCERRI interrupt. • 1 – VBERRE: VBus Error Interrupt Enable bit Set to enable the VBERRI interrupt. Clear to disable the VBERRI interrupt. • 0 – SRPE: SRP Interrupt Enable bit Set to enable the SRPI interrupt. Clear to disable the SRPI interrupt. • 7-6 - Reserved The value read from these bits is always 0. Do not set these bits. • 5 – STOI: Suspend Time-out Error Interrupt flag Set by hardware when a time-out error (more than 150ms) has been detected after a suspend. Shall be cleared by software. • 4 – HNPERRI: HNP Error Interrupt flag Set by hardware when an error has been detected during the protocol. Shall be cleared by software. • 3 – ROLEEXI: Role Exchange Interrupt flag Set by hardware when the USB controller has successfully swapped its mode, due to an HNP negotiation: Host to Device or Device to Host. However the mode selection bit (Host/Device) is unchanged and must be changed by firmware in order to reach the correct RAM locations and events bits. Shall be cleared by software. Bit 7 6 5 4 3 2 1 0 - - STOE HNPERRE ROLEEXE BCERRE VBERRE SRPE OTGIEN Read/write R R R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - STOI HNPERRI ROLEEXI BCERRI VBERRI SRPI OTGINT Read/write R R R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0261 7593L–AVR–09/12 AT90USB64/128 • 2 – BCERRI: B-Connection Error Interrupt flag Set by hardware when an error occur during the B-Connection (that is, if Peripheral has not connected after 300ms of Vbus delivery request). Shall be cleared by software. • 1 – VBERRI: V-Bus Error Interrupt flag Set by hardware when a drop on VBus has been detected. Shall be cleared by software. • 0 – SRPI: SRP Interrupt flag Set by hardware when a SRP has been detected. Shall be used in the Host mode only. Shall be cleared by software. 22.13 USB Software Operating modes Depending on the USB operating mode, the software should perform some the following operations: Power On the USB interface • Power-On USB pads regulator • Configure PLL interface • Enable PLL and wait PLL lock • Enable USB interface • Configure USB interface (USB speed, Endpoints configuration...) • Wait for USB VBUS information connection • Attach USB device Power Off the USB interface • Detach USB interface • Disable USB interface • Disable PLL • Disable USB pad regulator Suspending the USB interface • Clear Suspend Bit • Freeze USB clock • Disable PLL • Be sure to have interrupts enable to exit sleep mode • Make the MCU enter sleep mode Resuming the USB interface • Enable PLL • Wait PLL lock • Unfreeze USB clock • Clear Resume information262 7593L–AVR–09/12 AT90USB64/128 23. USB device operating modes 23.1 Introduction The USB device controller supports full speed and low speed data transfers. In addition to the default control endpoint, it provides six other endpoints, which can be configured in control, bulk, interrupt or isochronous modes: • Endpoint 0:programmable size FIFO up to 64 bytes, default control endpoint • Endpoints 1 programmable size FIFO up to 256 bytes in ping-pong mode • Endpoints 2 to 6: programmable size FIFO up to 64 bytes in ping-pong mode The controller starts in the “idle” mode. In this mode, the pad consumption is reduced to the minimum. 23.2 Power-on and reset The next diagram explains the USB device controller main states on power-on: Figure 23-1. USB device controller states after reset. The reset state of the Device controller is: • the macro clock is stopped in order to minimize the power consumption (FRZCLK set) • the USB device controller internal state is reset (all the registers are reset to their default value. Note that DETACH is set.) • the endpoint banks are reset • the D+ or D- pull up are not activated (mode Detach) The D+ or D- pull-up will be activated as soon as the DETACH bit is cleared and VBUS is present. The macro is in the ‘Idle’ state after reset with a minimum power consumption and does not need to have the PLL activated to enter in this state. The USB device controller can at any time be reset by clearing USBE (disable USB interface). 23.3 Endpoint reset An endpoint can be reset at any time by setting in the UERST register the bit corresponding to the endpoint (EPRSTx). This resets: • the internal state machine on that endpoint • the Rx and Tx banks are cleared and their internal pointers are restored Reset Idle HW RESET USBE=0 USBE=0 USBE=1 UID=1263 7593L–AVR–09/12 AT90USB64/128 • the UEINTX, UESTA0X and UESTA1X are restored to their reset value The data toggle field remains unchanged. The other registers remain unchanged. The endpoint configuration remains active and the endpoint is still enabled. The endpoint reset may be associated with a clear of the data toggle command (RSTDT bit) as an answer to the CLEAR_FEATURE USB command. 23.4 USB reset When an USB reset is detected on the USB line, the next operations are performed by the controller: • all the endpoints are disabled • the default control endpoint remains configured (see Section 23.3, page 262 for more details) 23.5 Endpoint selection Prior to any operation performed by the CPU, the endpoint must first be selected. This is done by setting the EPNUM2:0 bits (UENUM register) with the endpoint number which will be managed by the CPU. The CPU can then access to the various endpoint registers and data. 23.6 Endpoint activation The endpoint is maintained under reset as long as the EPEN bit is not set. The following flow must be respected in order to activate an endpoint:264 7593L–AVR–09/12 AT90USB64/128 Figure 23-2. Endpoint activation flow. As long as the endpoint is not correctly configured (CFGOK cleared), the hardware does not acknowledge the packets sent by the host. CFGOK is will not be sent if the Endpoint size parameter is bigger than the DPRAM size. A clear of EPEN acts as an endpoint reset (see Section 23.3, page 262 for more details). It also performs the next operation: • The configuration of the endpoint is kept (EPSIZE, EPBK, ALLOC kept) • It resets the data toggle field • The DPRAM memory associated to the endpoint is still reserved See Section 22.7, page 252 for more details about the memory allocation/reorganization. 23.7 Address setup The USB device address is set up according to the USB protocol: • the USB device, after power-up, responds at address 0 • the host sends a SETUP command (SET_ADDRESS(addr)) • the firmware records that address in UADD, but keep ADDEN cleared • the USB device sends an IN command of 0 bytes (IN 0 Zero Length Packet) • then, the firmware can enable the USB device address by setting ADDEN. The only accepted address by the controller is the one stored in UADD ADDEN and UADD shall not be written at the same time. UADD contains the default address 00h after a power-up or USB reset. Endpoint Activation CFGOK=1 ERROR No Yes Endpoint activated Activate the endpoint Select the endpoint EPEN=1 UENUM EPNUM=x Test the correct endpoint configuration UECFG1X ALLOC EPSIZE EPBK Configure: - the endpoint size - the bank parametrization Allocation and reorganization of the memory is made on-the-fly UECFG0X EPDIR EPTYPE ... Configure: - the endpoint direction - the endpoint type265 7593L–AVR–09/12 AT90USB64/128 ADDEN is cleared by hardware: • after a power-up reset • when an USB reset is received • or when the macro is disabled (USBE cleared) When this bit is cleared, the default device address 00h is used. 23.8 Suspend, wake-up and resume After a period of 3ms during which the USB line was inactive, the controller switches to the fullspeed mode and triggers (if enabled) the SUSPI (suspend) interrupt. The firmware may then set the FRZCLK bit. The CPU can also, depending on software architecture, enter in the idle mode to lower again the power consumption. There are two ways to recover from the “Suspend” mode: • First one is to clear the FRZCLK bit. This is possible if the CPU is not in the Idle mode • Second way, if the CPU is “idle”, is to enable the WAKEUPI interrupt (WAKEUPE set). Then, as soon as an non-idle signal is seen by the controller, the WAKEUPI interrupt is triggered. The firmware shall then clear the FRZCLK bit to restart the transfer There are no relationship between the SUSPI interrupt and the WAKEUPI interrupt: the WAKEUPI interrupt is triggered as soon as there are non-idle patterns on the data lines. Thus, the WAKEUPI interrupt can occurs even if the controller is not in the “suspend” mode. When the WAKEUPI interrupt is triggered, if the SUSPI interrupt bit was already set, it is cleared by hardware. When the SUSPI interrupt is triggered, if the WAKEUPI interrupt bit was already set, it is cleared by hardware. 23.9 Detach The reset value of the DETACH bit is 1. It is possible to re-enumerate a device, simply by setting and clearing the DETACH bit. • Setting DETACH will disconnect the pull-up on the D+ or D- pad (depending on full or low speed mode selected). Then, clearing DETACH will connect the pull-up on the D+ or D- pad Figure 23-3. Detach a device in full-speed. EN=1 D + UVREF D - Detach, then Attach EN=1 D + UVREF D -266 7593L–AVR–09/12 AT90USB64/128 23.10 Remote Wake-up The “Remote Wake-up” (or “upstream resume”) request is the only operation allowed to be sent by the device on its own initiative. Anyway, to do that, the device should first have received a DEVICE_REMOTE_WAKEUP request from the host. • First, the USB controller must have detected the “suspend” state of the line: the remote wakeup can only be sent when a SUSPI flag is set • The firmware has then the ability to set RMWKUP to send the “upstream resume” stream. This will automatically be done by the controller after 5ms of inactivity on the USB line • When the controller starts to send the “upstream resume”, the UPRSMI interrupt is triggered (if enabled). SUSPI is cleared by hardware • RMWKUP is cleared by hardware at the end of the “upstream resume” • If the controller detects a good “End Of Resume” signal from the host, an EORSMI interrupt is triggered (if enabled) 23.11 STALL request For each endpoint, the STALL management is performed using two bits: – STALLRQ (enable stall request) – STALLRQC (disable stall request) – STALLEDI (stall sent interrupt) To send a STALL handshake at the next request, the STALLRQ request bit has to be set. All following requests will be handshak’ed with a STALL until the STALLRQC bit is set. Setting STALLRQC automatically clears the STALLRQ bit. The STALLRQC bit is also immediately cleared by hardware after being set by software. Thus, the firmware will never read this bit as set. Each time the STALL handshake is sent, the STALLEDI flag is set by the USB controller and the EPINTx interrupt will be triggered (if enabled). The incoming packets will be discarded (RXOUTI and RWAL will not be set). The host will then send a command to reset the STALL: the firmware just has to set the STALLRQC bit and to reset the endpoint. 23.11.1 Special consideration for control endpoints A SETUP request is always ACK’ed. If a STALL request is set for a Control Endpoint and if a SETUP request occurs, the SETUP request has to be ACK’ed and the STALLRQ request and STALLEDI sent flags are automatically reset (RXSETUPI set, TXIN cleared, STALLED cleared, TXINI cleared...). This management simplifies the enumeration process management. If a command is not supported or contains an error, the firmware set the STALL request flag and can return to the main task, waiting for the next SETUP request. This function is compliant with the Chapter 8 test that may send extra status for a GET_DESCRIPTOR. The firmware sets the STALL request just after receiving the status. All extra status will be automatically STALL’ed until the next SETUP request.267 7593L–AVR–09/12 AT90USB64/128 23.11.2 STALL handshake and retry mechanism The Retry mechanism has priority over the STALL handshake. A STALL handshake is sent if the STALLRQ request bit is set and if there is no retry required. 23.12 CONTROL endpoint management A SETUP request is always ACK’ed. When a new setup packet is received, the RXSTPI interrupt is triggered (if enabled). The RXOUTI interrupt is not triggered. The FIFOCON and RWAL fields are irrelevant with CONTROL endpoints. The firmware shall thus never use them on that endpoints. When read, their value is always 0. CONTROL endpoints are managed by the following bits: • RXSTPI is set when a new SETUP is received. It shall be cleared by firmware to acknowledge the packet and to clear the endpoint bank • RXOUTI is set when a new OUT data is received. It shall be cleared by firmware to acknowledge the packet and to clear the endpoint bank • TXINI is set when the bank is ready to accept a new IN packet. It shall be cleared by firmware to send the packet and to clear the endpoint bank 23.12.1 Control write Figure 23-4 shows a control write transaction. During the status stage, the controller will not necessary send a NAK at the first IN token: • If the firmware knows the exact number of descriptor bytes that must be read, it can then anticipate on the status stage and send a ZLP for the next IN token • or it can read the bytes and poll NAKINI, which tells that all the bytes have been sent by the host, and the transaction is now in the status stage Figure 23-4. Control write transaction. 23.12.2 Control read Figure 23-5 on page 268 shows a control read transaction. The USB controller has to manage the simultaneous write requests from the CPU and the USB host. SETUP RXSTPI RXOUTI TXINI USB line HW SW OUT HW SW OUT HW SW IN IN NAK SW SETUP STATUS DATA268 7593L–AVR–09/12 AT90USB64/128 Figure 23-5. Control read transaction. A NAK handshake is always generated at the first status stage command. When the controller detect the status stage, all the data writen by the CPU are erased, and clearing TXINI has no effects. The firmware checks if the transmission is complete or if the reception is complete. The OUT retry is always ack’ed. This reception: - set the RXOUTI flag (received OUT data) - set the TXINI flag (data sent, ready to accept new data) software algorithm: set transmit ready wait (transmit complete OR Receive complete) if receive complete, clear flag and return if transmit complete, continue Once the OUT status stage has been received, the USB controller waits for a SETUP request. The SETUP request have priority over any other request and has to be ACK’ed. This means that any other flag should be cleared and the fifo reset when a SETUP is received. WARNING: the byte counter is reset when the OUT Zero Length Packet is received. The firmware has to take care of this. 23.13 OUT endpoint management OUT packets are sent by the host. All the data can be read by the CPU, which acknowledges or not the bank when it is empty. 23.13.1 Overview The Endpoint must be configured first. Each time the current bank is full, the RXOUTI and the FIFOCON bits are set. This triggers an interrupt if the RXOUTE bit is set. The firmware can acknowledge the USB interrupt by clearing the RXOUTI bit. The Firmware read the data and clear the FIFOCON bit in order to free the current bank. If the OUT Endpoint is composed of multiple banks, clearing the FIFOCON bit will switch to the next bank. The RXOUTI and FIFOCON bits are then updated by hardware in accordance with the status of the new bank. SETUP RXSTPI RXOUTI TXINI USB line HW SW IN HW SW IN OUT OUT NAK SW SW HW Wr Enable HOST Wr Enable CPU SETUP STATUS DATA269 7593L–AVR–09/12 AT90USB64/128 RXOUTI shall always be cleared before clearing FIFOCON. The RWAL bit always reflects the state of the current bank. This bit is set if the firmware can read data from the bank, and cleared by hardware when the bank is empty. Figure 23-6. Example with 1 and 2 OUT data bank. 23.13.2 Detailed description The data are read by the CPU, following the next flow: • When the bank is filled by the host, an endpoint interrupt (EPINTx) is triggered, if enabled (RXOUTE set) and RXOUTI is set. The CPU can also poll RXOUTI or FIFOCON, depending on the software architecture • The CPU acknowledges the interrupt by clearing RXOUTI • The CPU can read the number of byte (N) in the current bank (N=BYCT) • The CPU can read the data from the current bank (“N” read of UEDATX) • The CPU can free the bank by clearing FIFOCON when all the data is read, that is: – after “N” read of UEDATX – as soon as RWAL is cleared by hardware If the endpoint uses two banks, the second one can be filled by the HOST while the current one is being read by the CPU. Then, when the CPU clear FIFOCON, the next bank may be already ready and RXOUTI is set immediately. 23.14 IN endpoint management IN packets are sent by the USB device controller, upon an IN request from the host. All the data can be written by the CPU, which acknowledge or not the bank when it is full. OUT DATA (to bank 0) ACK RXOUTI FIFOCON HW OUT DATA (to bank 0) ACK HW SW SW SW read data from CPU BANK 0 OUT DATA (to bank 0) ACK RXOUTI FIFOCON HW OUT DATA (to bank 1) ACK SW SW Example with 2 OUT data banks read data from CPU BANK 0 HW SW read data from CPU BANK 0 read data from CPU BANK 1 NAK270 7593L–AVR–09/12 AT90USB64/128 23.14.1 Overview The Endpoint must be configured first. The TXINI bit is set by hardware when the current bank becomes free. This triggers an interrupt if the TXINE bit is set. The FIFOCON bit is set at the same time. The CPU writes into the FIFO and clears the FIFOCON bit to allow the USB controller to send the data. If the IN Endpoint is composed of multiple banks, this also switches to the next data bank. The TXINI and FIFOCON bits are automatically updated by hardware regarding the status of the next bank. TXINI shall always be cleared before clearing FIFOCON. The RWAL bit always reflects the state of the current bank. This bit is set if the firmware can write data to the bank, and cleared by hardware when the bank is full. Figure 23-7. Example with 1 and 2 IN data bank. 23.14.2 Detailed description The data are written by the CPU, following the next flow: • When the bank is empty, an endpoint interrupt (EPINTx) is triggered, if enabled (TXINE set) and TXINI is set. The CPU can also poll TXINI or FIFOCON, depending the software architecture choice • The CPU acknowledges the interrupt by clearing TXINI • The CPU can write the data into the current bank (write in UEDATX) • The CPU can free the bank by clearing FIFOCON when all the data are written, that is: – after “N” write into UEDATX – as soon as RWAL is cleared by hardware IN DATA (bank 0) ACK TXINI FIFOCON HW write data from CPU BANK 0 Example with 2 IN data banks SW SW SW SW IN IN DATA (bank 0) ACK TXINI FIFOCON write data from CPU BANK 0 SW SW SW SW IN DATA (bank 1) ACK write data from CPU BANK 0 write data from CPU BANK 1 SW HW write data from CPU BANK0 NAK271 7593L–AVR–09/12 AT90USB64/128 If the endpoint uses two banks, the second one can be read by the HOST while the current is being written by the CPU. Then, when the CPU clears FIFOCON, the next bank may be already ready (free) and TXINI is set immediately. 23.14.2.1 Abort An “abort” stage can be produced by the host in some situations: • In a control transaction: ZLP data OUT received during a IN stage • In an isochronous IN transaction: ZLP data OUT received on the OUT endpoint during a IN stage on the IN endpoint • ... The KILLBK bit is used to kill the last “written” bank. The best way to manage this abort is to perform the following operations: Table 23-1. Abort flow. 23.15 Isochronous mode 23.15.1 Underflow An underflow can occur during IN stage if the host attempts to read a bank which is empty. In this situation, the UNDERFI interrupt is triggered. An underflow can also occur during OUT stage if the host send a packet while the banks are already full. Typically, he CPU is not fast enough. The packet is lost. It is not possible to have underflow error during OUT stage, in the CPU side, since the CPU should read only if the bank is ready to give data (RXOUTI=1 or RWAL=1) 23.15.2 CRC error A CRC error can occur during OUT stage if the USB controller detects a bad received packet. In this situation, the STALLEDI interrupt is triggered. This does not prevent the RXOUTI interrupt from being triggered. Endpoint Abort Abort done Abort is based on the fact that no banks are busy, meaning that nothing has to be sent. Disable the TXINI interrupt. Endpoint reset NBUSYBK =0 Yes Clear UEIENX. TXINE No KILLBK=1 KILLBK=1 Yes Kill the last written bank. Wait for the end of the procedure. No272 7593L–AVR–09/12 AT90USB64/128 23.16 Overflow In Control, Isochronous, Bulk or Interrupt Endpoint, an overflow can occur during OUT stage, if the host attempts to write in a bank that is too small for the packet. In this situation, the OVERFI interrupt is triggered (if enabled). The packet is acknowledged and the RXOUTI interrupt is also triggered (if enabled). The bank is filled with the first bytes of the packet. It is not possible to have overflow error during IN stage, in the CPU side, since the CPU should write only if the bank is ready to access data (TXINI=1 or RWAL=1). 23.17 Interrupts Figure 23-8 shows all the interrupts sources. Figure 23-8. USB device controller interrupt system. There are two kinds of interrupts: processing (that is, their generation are part of the normal processing) and exception (errors). Processing interrupts are generated when: • VBUS plug-in detection (insert, remove)(VBUSTI) • Upstream resume(UPRSMI) • End of resume(EORSMI) • Wake up(WAKEUPI) • End of reset (Speed Initialization)(EORSTI) • Start of frame(SOFI, if FNCERR=0) • Suspend detected after 3ms of inactivity(SUSPI) Exception Interrupts are generated when: • CRC error in frame number of SOF(SOFI, FNCERR=1) UPRSMI UDINT.6 UPRSME UDIEN.6 EORSMI UDINT.5 EORSME UDIEN.5 WAKEUPI UDINT.4 WAKEUPE UDIEN.4 EORSTI UDINT.3 EORSTE UDIEN.3 SOFI UDINT.2 SOFE UDIEN.2 SUSPI UDINT.0 SUSPE UDIEN.0 USB device interrupt273 7593L–AVR–09/12 AT90USB64/128 Figure 23-9. USB device controller endpoint interrupt system. Processing interrupts are generated when: • Ready to accept IN data(EPINTx, TXINI=1) • Received OUT data(EPINTx, RXOUTI=1) • Received SETUP(EPINTx, RXSTPI=1) Exception Interrupts are generated when: • Stalled packet(EPINTx, STALLEDI=1) • CRC error on OUT in isochronous mode(EPINTx, STALLEDI=1) • Overflow in isochronous mode(EPINTx, OVERFI=1) • Underflow in isochronous mode(EPINTx, UNDERFI=1) • NAK IN sent(EPINTx, NAKINI=1) • NAK OUT sent(EPINTx, NAKOUTI=1) 23.18 Registers 23.18.1 USB device general registers EPINT UEINT.X Endpoint 0 Endpoint 1 Endpoint 2 Endpoint 3 Endpoint 4 Endpoint 5 Endpoint interrupt Endpoint 6 FLERRE UEIENX.7 OVERFI UESTAX.6 UNDERFI UESTAX.5 NAKINI UEINTX.6 NAKINE UEIENX.6 NAKOUTI UEINTX.4 TXSTPE UEIENX.4 RXSTPI UEINTX.3 TXOUTE UEIENX.3 RXOUTI UEINTX.2 RXOUTE UEIENX.2 STALLEDI UEINTX.1 STALLEDE UEIENX.1 TXINI UEINTX.0 TXINE UEIENX.0 Bit 7 6 5 4 3 2 1 0 ----- LSM RMWKUP DETACH UDCON Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 1274 7593L–AVR–09/12 AT90USB64/128 • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2 - LSM - USB Device Low Speed Mode selection When configured USB is configured in device mode, this bit allows to select the USB the USB Low Speed or Full Speed Mod. Clear to select full speed mode (D+ internal pull-up will be activate with the ATTACH bit will be set) . Set to select low speed mode (D- internal pull-up will be activate with the ATTACH bit will be set). This bit has no effect when the USB interface is configured in HOST mode. • 1- RMWKUP - Remote Wake-up bit Set to send an “upstream-resume” to the host for a remote wake-up (the SUSPI bit must be set). Cleared by hardware when signalling finished. Clearing by software has no effect. See Section 23.10, page 266 for more details. • 0 - DETACH - Detach bit Set to physically detach de device (disconnect internal pull-up on D+ or D-). Clear to reconnect the device. See Section 23.9, page 265 for more details. • 7 - Reserved The value read from this bits is always 0. Do not set this bit. • 6 - UPRSMI - Upstream Resume Interrupt flag Set by hardware when the USB controller is sending a resume signal called “Upstream Resume”. This triggers an USB interrupt if UPRSME is set. Shall be cleared by software (USB clocks must be enabled before). Setting by software has no effect. • 5 - EORSMI - End Of Resume Interrupt flag Set by hardware when the USB controller detects a good “End Of Resume” signal initiated by the host. This triggers an USB interrupt if EORSME is set. Shall be cleared by software. Setting by software has no effect. • 4 - WAKEUPI - Wake-up CPU Interrupt flag Set by hardware when the USB controller is re-activated by a filtered non-idle signal from the lines (not by an upstream resume). This triggers an interrupt if WAKEUPE is set. This interrupt should be enable only to wake up the CPU core from power down mode. Shall be cleared by software (USB clock inputs must be enabled before). Setting by software has no effect. See Section 23.8, page 265 for more details. Bit 7 6 5 4 3 2 1 0 - UPRSMI EORSMI WAKEUPI EORSTI SOFI - SUSPI UDINT Read/write Initial value 0 0 0 0 0 0 0 0275 7593L–AVR–09/12 AT90USB64/128 • 3 - EORSTI - End Of Reset Interrupt flag Set by hardware when an “End Of Reset” has been detected by the USB controller. This triggers an USB interrupt if EORSTE is set. Shall be cleared by software. Setting by software has no effect. • 2 - SOFI - Start Of Frame Interrupt flag Set by hardware when an USB “Start Of Frame” PID (SOF) has been detected (every 1ms). This triggers an USB interrupt if SOFE is set. • 1 - Reserved The value read from this bits is always 0. Do not set this bit • 0 - SUSPI - Suspend Interrupt flag Set by hardware when an USB “Suspend” ‘idle bus for three frame periods: a J state for 3ms) is detected. This triggers an USB interrupt if SUSPE is set. Shall be cleared by software. Setting by software has no effect. See Section 23.8, page 265 for more details. The interrupt bits are set even if their corresponding ‘Enable’ bits is not set. • 7 - Reserved The value read from this bits is always 0. Do not set this bit. • 6 - UPRSME - Upstream Resume Interrupt Enable bit Set to enable the UPRSMI interrupt. Clear to disable the UPRSMI interrupt. • 5 - EORSME - End Of Resume Interrupt Enable bit Set to enable the EORSMI interrupt. Clear to disable the EORSMI interrupt. • 4 - WAKEUPE - Wake-up CPU Interrupt Enable bit Set to enable the WAKEUPI interrupt. For correct interrupt handle execution, this interrupt should be enable only before entering power-down mode. Clear to disable the WAKEUPI interrupt. • 3 - EORSTE - End Of Reset Interrupt Enable bit Set to enable the EORSTI interrupt. This bit is set after a reset. Clear to disable the EORSTI interrupt. • 2 - SOFE - Start Of Frame Interrupt Enable bit Set to enable the SOFI interrupt. Clear to disable the SOFI interrupt. Bit 7 6 5 4 3 2 1 0 - UPRSME EORSME WAKEUPE EORSTE SOFE - SUSPE UDIEN Read/write Initial value 0 0 0 0 0 0 0 0276 7593L–AVR–09/12 AT90USB64/128 • 1 - Reserved The value read from this bits is always 0. Do not set this bit • 0 - SUSPE - Suspend Interrupt Enable Bit Set to enable the SUSPI interrupt. Clear to disable the SUSPI interrupt. • 7 - ADDEN - Address Enable Bit Set to activate the UADD (USB address). Cleared by hardware. Clearing by software has no effect. See Section 23.7, page 264 for more details. • 6-0 - UADD6:0 - USB Address Bits Load by software to configure the device address. • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2-0 - FNUM10:8 - Frame Number Upper Value Set by hardware. These bits are the three MSB of the 11-bits Frame Number information. They are provided in the last received SOF packet. FNUM is updated if a corrupted SOF is received. • Frame Number Lower Value Set by hardware. These bits are the eight LSB of the 11-bits Frame Number information. • 7-5 - Reserved The value read from these bits is always 0. Do not set these bits. • 4 - FNCERR -Frame Number CRC Error flag Set by hardware when a corrupted Frame Number in start of frame packet is received. This bit and the SOFI interrupt are updated at the same time. Bit 7 6 5 4 3 2 1 0 ADDEN UADD6:0 UDADDR Read/write W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - - - - FNUM10:8 UDFNUMH Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 FNUM7:0 UDFNUML Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - - FNCERR - - - - UDMFN Read/write R Initial value 0 0 0 0 0 0 0 0277 7593L–AVR–09/12 AT90USB64/128 • 3-0 - Reserved The value read from these bits is always 0. Do not set these bits. 23.18.2 USB device endpoint registers • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2-0 - EPNUM2:0 Endpoint Number bits Load by software to select the number of the endpoint which shall be accessed by the CPU. See Section 23.5, page 263 for more details. EPNUM = 111b is forbidden. • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6-0 - EPRST6:0 - Endpoint FIFO Reset bits Set to reset the selected endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. See Section 23.3, page 262 for more information Then, clear by software to complete the reset operation and start using the endpoint. • 7-6 - Reserved The value read from these bits is always 0. Do not set these bits. • 5 - STALLRQ - STALL Request Handshake bit Set to request a STALL answer to the host for the next handshake. Cleared by hardware when a new SETUP is received. Clearing by software has no effect. See Section 23.11, page 266 for more details. • 4 - STALLRQC - STALL Request Clear Handshake bit Set to disable the STALL handshake mechanism. Cleared by hardware immediately after the set. Clearing by software has no effect. See Section 23.11, page 266 for more details. Bit 7 6 5 4 3 2 1 0 - - - - - EPNUM2:0 UENUM Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - EPRST6 EPRST5 EPRST4 EPRST3 EPRST2 EPRST1 EPRST0 UERST Read/write R R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - STALLRQ STALLRQC RSTDT - - EPEN UECONX Read/write R R W W W R R R/W Initial value 0 0 0 0 0 0 0 0278 7593L–AVR–09/12 AT90USB64/128 • RSTDT - Reset Data Toggle bit Set to automatically clear the data toggle sequence: For OUT endpoint: the next received packet will have the data toggle 0. For IN endpoint: the next packet to be sent will have the data toggle 0. Cleared by hardware instantaneously. The firmware does not have to wait that the bit is cleared. Clearing by software has no effect. • 2 - Reserved The value read from these bits is always 0. Do not set these bits. • 1 - Reserved The value read from these bits is always 0. Do not set these bits. • 0 - EPEN - Endpoint Enable bit Set to enable the endpoint according to the device configuration. Endpoint 0 shall always be enabled after a hardware or USB reset and participate in the device configuration. Clear this bit to disable the endpoint. See Section 23.6, page 263 for more details. • 7-6 - EPTYPE1:0 - Endpoint Type bits Set this bit according to the endpoint configuration: 00b: Control10b: Bulk 01b: Isochronous11b: Interrupt • 5-4 - Reserved The value read from these bits is always 0. Do not set these bits. • 3-2 - Reserved for test purpose The value read from these bits is always 0. Do not set these bits. • 1 - Reserved The value read from this bits is always 0. Do not set this bit. • 0 - EPDIR - Endpoint Direction bit Set to configure an IN direction for bulk, interrupt or isochronous endpoints. Clear to configure an OUT direction for bulk, interrupt, isochronous or control endpoints. Bit 7 6 5 4 3 2 1 0 EPTYPE1:0 - - - - - EPDIR UECFG0X Read/write R/W R/W R R R R R R/W Initial value 0 0 0 0 0 0 0 0279 7593L–AVR–09/12 AT90USB64/128 • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6-4 - EPSIZE2:0 - Endpoint Size bits Set this bit according to the endpoint size: 000b: 8 bytes 100b: 128 bytes (only for endpoint 1) 001b: 16 bytes 101b: 256 bytes (only for endpoint 1) 010b: 32 bytes 110b: Reserved. Do not use this configuration 011b: 64 bytes 111b: Reserved. Do not use this configuration • 3-2 - EPBK1:0 - Endpoint Bank bits Set this field according to the endpoint size: 00b: One bank 01b: Double bank 1xb: Reserved. Do not use this configuration • 1 - ALLOC - Endpoint Allocation bit Set this bit to allocate the endpoint memory. Clear to free the endpoint memory. See Section 23.6, page 263 for more details. • 0 - Reserved The value read from these bits is always 0. Do not set these bits. • 7 - CFGOK - Configuration Status flag Set by hardware when the endpoint X size parameter (EPSIZE) and the bank parametrization (EPBK) are correct compared to the max FIFO capacity and the max number of allowed bank. This bit is updated when the bit ALLOC is set. If this bit is cleared, the user should reprogram the UECFG1X register with correct EPSIZE and EPBK values. Bit 7 6 5 4 3 2 1 0 - EPSIZE2:0 EPBK1:0 ALLOC - UECFG1X Read/write R R/W R/W R/W R/W R/W R/W R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 CFGOK OVERFI UNDERFI - DTSEQ1:0 NBUSYBK1:0 UESTA0X Read/write R R/W R/W R/W R R R R Initial value 0 0 0 0 0 0 0 0280 7593L–AVR–09/12 AT90USB64/128 • 6 - OVERFI - Overflow Error Interrupt flag Set by hardware when an overflow error occurs in an isochronous endpoint. An interrupt (EPINTx) is triggered (if enabled). See Section 23.15, page 271 for more details. Shall be cleared by software. Setting by software has no effect. • 5 - UNDERFI - Flow Error Interrupt flag Set by hardware when an underflow error occurs in an isochronous endpoint. An interrupt (EPINTx) is triggered (if enabled). See Section 23.15, page 271 for more details. Shall be cleared by software. Setting by software has no effect. • 4 - Reserved The value read from these bits is always 0. Do not set these bits. • 3-2 - DTSEQ1:0 - Data Toggle Sequencing flag Set by hardware to indicate the PID data of the current bank: 00b Data0 01b Data1 1xb Reserved For OUT transfer, this value indicates the last data toggle received on the current bank. For IN transfer, it indicates the Toggle that will be used for the next packet to be sent. This is not relative to the current bank. • 1-0 - NBUSYBK1:0 - Busy Bank flag Set by hardware to indicate the number of busy bank. For IN endpoint, it indicates the number of busy bank(s), filled by the user, ready for IN transfer. For OUT endpoint, it indicates the number of busy bank(s) filled by OUT transaction from the host. 00b All banks are free 01b One busy bank 10b Two busy banks 11b Reserved • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. Bit 7 6 5 4 3 2 1 0 - - - - - CTRLDIR CURRBK1:0 UESTA1X Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0281 7593L–AVR–09/12 AT90USB64/128 • 2 - CTRLDIR - Control Direction (flag, and bit for debug purpose) Set by hardware after a SETUP packet, and gives the direction of the following packet: - 1 for IN endpoint - 0 for OUT endpoint Can not be set or cleared by software. • 1-0 - CURRBK1:0 - Current Bank (all endpoints except Control endpoint) flag Set by hardware to indicate the number of the current bank: 00b Bank0 01b Bank1 1xb Reserved Can not be set or cleared by software. • 7 - FIFOCON - FIFO Control bit For OUT and SETUP Endpoint: Set by hardware when a new OUT message is stored in the current bank, at the same time than RXOUT or RXSTP. Clear to free the current bank and to switch to the following bank. Setting by software has no effect. For IN Endpoint: Set by hardware when the current bank is free, at the same time than TXIN. Clear to send the FIFO data and to switch the bank. Setting by software has no effect. • 6 - NAKINI - NAK IN Received Interrupt flag Set by hardware when a NAK handshake has been sent in response of a IN request from the host. This triggers an USB interrupt if NAKINE is sent. Shall be cleared by software. Setting by software has no effect. • 5 - RWAL - Read/Write Allowed flag Set by hardware to signal: - for an IN endpoint: the current bank is not full, that is, the firmware can push data into the FIFO, - for an OUT endpoint: the current bank is not empty, that is, the firmware can read data from the FIFO. The bit is never set if STALLRQ is set, or in case of error. Cleared by hardware otherwise. This bit shall not be used for the control endpoint. Bit 7 6 5 4 3 2 1 0 FIFOCON NAKINI RWAL NAKOUTI RXSTPI RXOUTI STALLEDI TXINI UEINTX Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0282 7593L–AVR–09/12 AT90USB64/128 • 4 - NAKOUTI - NAK OUT Received Interrupt flag Set by hardware when a NAK handshake has been sent in response of a OUT/PING request from the host. This triggers an USB interrupt if NAKOUTE is sent. Shall be cleared by software. Setting by software has no effect. • 3 - RXSTPI - Received SETUP Interrupt flag Set by hardware to signal that the current bank contains a new valid SETUP packet. An interrupt (EPINTx) is triggered (if enabled). Shall be cleared by software to handshake the interrupt. Setting by software has no effect. This bit is inactive (cleared) if the endpoint is an IN endpoint. • 2 - RXOUTI / KILLBK - Received OUT Data Interrupt flag Set by hardware to signal that the current bank contains a new packet. An interrupt (EPINTx) is triggered (if enabled). Shall be cleared by software to handshake the interrupt. Setting by software has no effect. Kill Bank IN bit Set this bit to kill the last written bank. Cleared by hardware when the bank is killed. Clearing by software has no effect. See page 271 for more details on the Abort. • 1 - STALLEDI - STALLEDI Interrupt flag Set by hardware to signal that a STALL handshake has been sent, or that a CRC error has been detected in a OUT isochronous endpoint. Shall be cleared by software. Setting by software has no effect. • 0 - TXINI - Transmitter Ready Interrupt flag Set by hardware to signal that the current bank is free and can be filled. An interrupt (EPINTx) is triggered (if enabled). Shall be cleared by software to handshake the interrupt. Setting by software has no effect. This bit is inactive (cleared) if the endpoint is an OUT endpoint. • 7 - FLERRE - Flow Error Interrupt Enable flag Set to enable an endpoint interrupt (EPINTx) when OVERFI or UNDERFI are sent. Clear to disable an endpoint interrupt (EPINTx) when OVERFI or UNDERFI are sent. • 6 - NAKINE - NAK IN Interrupt Enable bit Set to enable an endpoint interrupt (EPINTx) when NAKINI is set. Clear to disable an endpoint interrupt (EPINTx) when NAKINI is set. Bit 7 6 5 4 3 2 1 0 FLERRE NAKINE - NAKOUTE RXSTPE RXOUTE STALLEDE TXINE UEIENX Read/write R/W R/W R R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0283 7593L–AVR–09/12 AT90USB64/128 • 5 - Reserved The value read from these bits is always 0. Do not set these bits. • 4 - NAKOUTE - NAK OUT Interrupt Enable bit Set to enable an endpoint interrupt (EPINTx) when NAKOUTI is set. Clear to disable an endpoint interrupt (EPINTx) when NAKOUTI is set. • 3 - RXSTPE - Received SETUP Interrupt Enable flag Set to enable an endpoint interrupt (EPINTx) when RXSTPI is sent. Clear to disable an endpoint interrupt (EPINTx) when RXSTPI is sent. • 2 - RXOUTE - Received OUT Data Interrupt Enable flag Set to enable an endpoint interrupt (EPINTx) when RXOUTI is sent. Clear to disable an endpoint interrupt (EPINTx) when RXOUTI is sent. • 1 - STALLEDE - Stalled Interrupt Enable flag Set to enable an endpoint interrupt (EPINTx) when STALLEDI is sent. Clear to disable an endpoint interrupt (EPINTx) when STALLEDI is sent. • 0 - TXINE - Transmitter Ready Interrupt Enable flag Set to enable an endpoint interrupt (EPINTx) when TXINI is sent. Clear to disable an endpoint interrupt (EPINTx) when TXINI is sent. • 7-0 - DAT7:0 -Data bits Set by the software to read/write a byte from/to the endpoint FIFO selected by EPNUM. • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2-0 - BYCT10:8 - Byte count (high) bits Set by hardware. This field is the MSB of the byte count of the FIFO endpoint. The LSB part is provided by the UEBCLX register. Bit 7 6 5 4 3 2 1 0 DAT D7 DAT D6 DAT D5 DAT D4 DAT D3 DAT D2 DAT D1 DAT D0 UEDATX Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - - - - BYCT D10 BYCT D9 BYCT D8 UEBCHX Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0284 7593L–AVR–09/12 AT90USB64/128 • 7-0 - BYCT7:0 - Byte Count (low) bits Set by the hardware. BYCT10:0 is: - (for IN endpoint) increased after each writing into the endpoint and decremented after each byte sent, - (for OUT endpoint) increased after each byte sent by the host, and decremented after each byte read by the software. • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6-0 - EPINT6:0 - Endpoint Interrupts bits Set by hardware when an interrupt is triggered by the UEINTX register and if the corresponding endpoint interrupt enable bit is set. Cleared by hardware when the interrupt source is served. Bit 7 6 5 4 3 2 1 0 BYCT D7 BYCT D6 BYCT D5 BYCT D4 BYCT D3 BYCT D2 BYCT D1 BYCT D0 UEBCLX Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - EPINT D6 EPINT D5 EPINT D4 EPINT D3 EPINT D2 EPINT D1 EPINT D0 UEINT Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0285 7593L–AVR–09/12 AT90USB64/128 24. USB host operating modes This mode is available only on Atmel AT90USB647/1287 products. 24.1 Pipe description For the USB Host controller, the term of Pipe is used instead of Endpoint for the USB Device controller. A Host Pipe corresponds to a Device Endpoint, as described in the USB specification. Figure 24-1. Pipes and endpoints in a USB system. In the USB Host controller, a Pipe will be associated to a Device Endpoint, considering the Device Configuration Descriptors. 24.2 Detach The reset value of the DETACH bit is 1. Thus, the firmware has the responsibility of clearing this bit before switching to the Host mode (HOST set). 24.3 Power-on and reset Figure 24-2 explains the USB host controller main states on power-on. Figure 24-2. USB host controller states after reset. Host Ready Host Idle Device disconnection Device connection Clock stopped Macro off Device disconnection Host Suspend SOFE=1 SOFE=0286 7593L–AVR–09/12 AT90USB64/128 USB host controller state after an hardware reset is ‘Reset’. When the USB controller is enabled and the USB Host controller is selected, the USB controller is in ‘Idle’ state. In this state, the USB Host controller waits for the Device connection, with a minimum power consumption. The USB Pad should be in Idle mode. The macro does not need to have the PLL activated to enter in ‘Host Ready’ state. The Host controller enters in Suspend state when the USB bus is in Suspend state, that is, when the Host controller doesn’t generate the Start of Frame. In this state, the USB consumption is minimum. The Host controller exits to the Suspend state when starting to generate the SOF over the USB line. 24.4 Device detection A Device is detected by the USB controller when the USB bus if different from D+ and D- low. In other words, when the USB Host Controller detects the Device pull-up on the D+ line. To enable this detection, the Host Controller has to provide the Vbus power supply to the Device. The Device Disconnection is detected by the USB Host controller when the USB Idle correspond to D+ and D- low on the USB line. 24.5 Pipe selection Prior to any operation performed by the CPU, the Pipe must first be selected. This is done by setting PNUM2:0 bits (UPNUM register) with the Pipe number which will be managed by the CPU. The CPU can then access to the various Pipe registers and data. 24.6 Pipe configuration The following flow (see Figure 24-3 on page 287) must be respected in order to activate a Pipe.287 7593L–AVR–09/12 AT90USB64/128 Figure 24-3. Pipe activation flow. Once the Pipe is activated (EPEN set) and, the hardware is ready to send requests to the Device. When configured (CFGOK = 1), only the Pipe Token (PTOKEN) and the polling interval for Interrupt pipe can be modified. A Control type pipe supports only one bank. Any other value will lead to a configuration error (CFGOK = 0). A clear of PEN will reset the configuration of the Pipe. All the corresponding Pipe registers are reset to there reset values. Please refer to “Memory management” on page 252 for more details. Note: The firmware has to configure the Default Control Pipe with the following parameters: • Type: Control • Token: SETUP • Data bank: 1 • Size: 64 Bytes The firmware asks for eight bytes of the Device Descriptor sending a GET_DESCRIPTOR request. These bytes contains the MaxPacketSize of the Device default control endpoint and the firmware re-configures the size of the Default Control Pipe with this size parameter. Pipe Activ ation UPCONX PENABLE=1 UPCFG0X PTYPE PTOKEN PEPNUM CFGOK=1 ERROR No Yes UPCFG2X INTFRQ (interrupt only) Pipe activ ated and f reezed UPCFG1X PSIZE PBK CFGMEM Enable the pipe Select the Pipe type: * Type (Control, Bulk, Interrupt) * Token (IN, OUT, SETUP) * Endpoint number Configure the Pipe memory: * Pipe size * Number of banks Configure the polling interval for Interrupt pipe288 7593L–AVR–09/12 AT90USB64/128 24.7 USB reset The USB controller sends a USB Reset when the firmware set the RESET bit. The RSTI bit is set by hardware when the USB Reset has been sent. This triggers an interrupt if the RSTE has been set. When a USB Reset has been sent, all the Pipe configuration and the memory allocation are reset. The General Host interrupt enable register is left unchanged. If the bus was previously in suspend mode (SOFEN = 0), the USB controller automatically switches to the resume mode (HWUPI is set) and the SOFEN bit is set by hardware in order to generate SOF immediately after the USB Reset. 24.8 Address setup Once the Device has answer to the first Host requests with the default address (0), the Host assigns a new address to the device. The Host controller has to send a USB reset to the device and perform a SET ADDRESS control request, with the new address to be used by the Device. This control request ended, the firmware write the new address into the UHADDR register. All following requests, on every Pipes, will be performed using this new address. When the Host controller send a USB reset, the UHADDR register is reset by hardware and the following Host requests will be performed using the default address (0). 24.9 Remote wake-up detection The Host Controller enters in Suspend mode when clearing the SOFEN bit. No more Start Of Frame is sent on the USB bus and the USB Device enters in Suspend mode 3ms later. The Device awakes the Host Controller by sending an Upstream Resume (Remote Wake-Up feature). The Host Controller detects a non-idle state on the USB bus and set the HWUPI bit. If the non-Idle correspond to an Upstream Resume (K state), the RXRSMI bit is set by hardware. The firmware has to generate a downstream resume within 1ms and for at least 20ms by setting the RESUME bit. Once the downstream Resume has been generated, the SOFEN bit is automatically set by hardware in order to generate SOF immediately after the USB resume. 24.10 USB pipe reset The firmware can reset a Pipe using the pipe reset register. The configuration of the pipe and the data toggle remains unchanged. Only the bank management and the status bits are reset to their initial values. To completely reset a Pipe, the firmware has to disable and then enable the pipe. 24.11 Pipe data access In order to read or to write into the Pipe Fifo, the CPU selects the Pipe number with the UPNUM register and performs read or write action on the UPDATX register. Host Ready Host Suspend SOFE=1 or HWUP=1 SOFE=0289 7593L–AVR–09/12 AT90USB64/128 24.12 Control pipe management A Control transaction is composed of three phases: • SETUP • Data (IN or OUT) • Status (OUT or IN) The firmware has to change the Token for each phase. The initial data toggle is set for the corresponding token (ONLY for Control Pipe): • SETUP: Data0 • OUT: Data1 • IN: Data1 (expected data toggle) 24.13 OUT pipe management The Pipe must be configured and not frozen first. Note: if the firmware decides to switch to suspend mode (clear SOFEN) even if a bank is ready to be sent, the USB controller will automatically exit from Suspend mode and the bank will be sent. The TXOUT bit is set by hardware when the current bank becomes free. This triggers an interrupt if the TXOUTE bit is set. The FIFOCON bit is set at the same time. The CPU writes into the FIFO and clears the FIFOCON bit to allow the USB controller to send the data. If the OUT Pipe is composed of multiple banks, this also switches to the next data bank. The TXOUT and FIFOCON bits are automatically updated by hardware regarding the status of the next bank.290 7593L–AVR–09/12 AT90USB64/128 Figure 24-4. Example with OUT data banks. 24.14 IN Pipe management The Pipe must be configured first. When the Host requires data from the device, the firmware has to determine first the IN mode to use using the INMODE bit: • INMODE = 0. The INRQX register is taken in account. The Host controller will perform (INRQX+1) IN requests on the selected Pipe before freezing the Pipe. This mode avoids to have extra IN requests on a Pipe • INMODE = 1. The USB controller will perform infinite IN request until the firmware freezes the Pipe The IN request generation will start when the firmware clear the PFREEZE bit. Each time the current bank is full, the RXIN and the FIFOCON bits are set. This triggers an interrupt if the RXINE bit is set. The firmware can acknowledge the USB interrupt by clearing the RXIN bit. The Firmware read the data and clear the FIFOCON bit in order to free the current OUT DATA (bank 0) ACK TXOUT FIFOCON HW Example with 1 OUT data bank write data from CPU BANK 0 Example with 2 OUT data banks SW SW SW SW OUT OUT DATA (bank 0) ACK TXOUT FIFOCON write data from CPU BANK 0 SW SW SW SW OUT DATA (bank 1) ACK write data from CPU BANK 0 write data from CPU BANK 1 SW HW write data from CPU BANK0 Example with 2 OUT data banks OUT DATA (bank 0) ACK TXOUT FIFOCON write data from CPU BANK 0 SW SW SW write data from CPU SW BANK 1 SW HW write data from CPU BANK0 OUT DATA (bank 1) ACK291 7593L–AVR–09/12 AT90USB64/128 bank. If the IN Pipe is composed of multiple banks, clearing the FIFOCON bit will switch to the next bank. The RXIN and FIFOCON bits are then updated by hardware in accordance with the status of the new bank. Figure 24-5. Example with IN data banks. 24.14.1 CRC error (isochronous only) A CRC error can occur during IN stage if the USB controller detects a bad received packet. In this situation, the STALLEDI/CRCERRI interrupt is triggered. This does not prevent the RXINI interrupt from being triggered. 24.15 Interrupt system Figure 24-6. USB host controller interrupt system. IN DATA (to bank 0) ACK RXIN FIFOCON HW IN DATA (to bank 0) ACK HW SW SW SW Example with 1 IN data bank read data from CPU BANK 0 IN DATA (to bank 0) ACK RXIN FIFOCON HW IN DATA (to bank 1) ACK SW SW Example with 2 IN data banks read data from CPU BANK 0 HW SW read data from CPU BANK 0 read data from CPU BANK 1 HWUPE UHIEN.6 HWUPI UHINT.6 HSOFI UHINT.5 HSOFE UHIEN.5 RXRSMI UHINT.4 RXRSME UHIEN.4 RSMEDI UHINT.3 RSMEDE UHIEN.3 RSTI UHINT.2 RSTE UHIEN.2 DDISCI UHINT.1 DDISCE UHIEN.1 DCONNI UHINT.0 DCONNE UHIEN.0 USB host interrupt292 7593L–AVR–09/12 AT90USB64/128 Figure 24-7. USB device controller pipe interrupt system. 24.16 Registers 24.16.1 General USB host registers • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2 - RESUME - Send USB Resume Set this bit to generate a USB Resume on the USB bus. Cleared by hardware when the USB Resume has been sent. Clearing by software has no effect. This bit should be set only when the start of frame generation is enable (SOFEN bit set). • 1 - RESET - Send USB Reset Set this bit to generate a USB Reset on the USB bus. Cleared by hardware when the USB Reset has been sent. Clearing by software has no effect. Refer to the USB reset section for more details. • 0 - SOFEN - Start Of Frame Generation Enable Set this bit to generate SOF on the USB bus in full speed mode and keep-alive in low speed mode. Clear this bit to disable the SOF generation and to leave the USB bus in Idle state. FLERRE UPIEN.7 UNDERFI UPSTAX.5 OVERFI UPSTAX.6 NAKEDI UPINTX.6 NAKEDE UPIEN.6 PERRI UPINTX.4 PERRE UPIEN.4 TXSTPI UPINTX.3 TXSTPE UPIEN.3 TXOUTI UPINTX.2 TXOUTE UPIEN.2 RXSTALLI UPINTX.1 RXSTALLE UPIEN.1 RXINI UPINTX.0 RXINE UPIEN.0 FLERRE UPIEN.7 PIPE 0 PIPE 1 PIPE 2 PIPE 3 PIPE 4 PIPE 5 Pipe interrupt PIPE 6 Bit 7 6 5 4 3 2 1 0 ----- RESUME RESET SOFEN UHCON Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0293 7593L–AVR–09/12 AT90USB64/128 • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6 - HWUPI - Host Wake-Up Interrupt Set by hardware when a non-idle state is detected on the USB bus.This interrupt should be enable only to wake up the CPU core from power down mode. Shall be clear by software to acknowledge the interrupt. Setting by software has no effect. • 5 - HSOFI - Host Start Of Frame Interrupt Set by hardware when a SOF is issued by the Host controller. This triggers a USB interrupt when HSOFE is set. When using the host controller in low speed mode, this bit is also set when a keep-alive is sent. Shall be cleared by software to acknowledge the interrupt. Setting by software has no effect. • 4 - RXRSMI - Upstream Resume Received Interrupt Set by hardware when an Upstream Resume has been received from the Device. Shall be cleared by software. Setting by software has no effect. • 3 - RSMEDI - Downstream Resume Sent Interrupt Set by hardware when a Downstream Resume has been sent to the Device. Shall be cleared by software. Setting by software has no effect. • 2 - RSTI - USB Reset Sent Interrupt Set by hardware when a USB Reset has been sent to the Device. Shall be cleared by software. Setting by software has no effect. • 1 - DDISCI - Device Disconnection Interrupt Set by hardware when the device has been removed from the USB bus. Shall be cleared by software. Setting by software has no effect. • 0 - DCONNI - Device Connection Interrupt Set by hardware when a new device has been connected to the USB bus. Shall be cleared by software. Setting by software has no effect. • 7 - Reserved The value read from these bits is always 0. Do not set these bits. Bit 7 6 5 4 3 2 1 0 - HWUPI HSOFI RXRSMI RSMEDI RSTI DDISCI DCONNI UHINT Read/write R R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 HWUPE HSOFE RXRSME RSMEDE RSTE DDISCE DCONNE UHIEN Read/write R R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0294 7593L–AVR–09/12 AT90USB64/128 • 6 - HWUPE - Host Wake-Up Interrupt Enable Set this bit to enable HWUP interrupt.For correct interrupt handle execution, this interrupt should be enable only before entering power-down mode. Clear this bit to disable HWUP interrupt. • 5 - HSOFE - Host Start Of frame Interrupt Enable Set this bit to enable HSOF interrupt. Clear this bit to disable HSOF interrupt. • 4 - RXRSME -Upstream Resume Received Interrupt Enable Set this bit to enable the RXRSMI interrupt. Clear this bit to disable the RXRSMI interrupt. • 3 - RSMEDE - Downstream Resume Sent Interrupt Enable Set this bit to enable the RSMEDI interrupt. Clear this bit to disable the RSMEDI interrupt. • 2 - RSTE - USB Reset Sent Interrupt Enable Set this bit to enable the RSTI interrupt. Clear this bit to disable the RSTI interrupt. • 1 - DDISCE - Device Disconnection Interrupt Enable Set this bit to enable the DDISCI interrupt. Clear this bit to disable the DDISCI interrupt. • 0 - DCONNE - Device Connection Interrupt Enable Set this bit to enable the DCONNI interrupt. Clear this bit to disable the DCONNI interrupt. • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6-0 - HADDR6:0 - USB Host Address These bits contain the address of the USB Device. Bit 7 6 5 4 3 2 1 0 HADDR6 HADDR5 HADDR4 HADDR3 HADDR2 HADDR1 HADDR0 HADDR6 UHADDR Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0295 7593L–AVR–09/12 AT90USB64/128 • 7-4 - Reserved The value read from these bits is always 0. Do not set these bits. • 3-0 - FNUM10:8 - Frame Number The value contained in this register is the current SOF number. This value can be modified by software. • 7-0 - FNUM7:0 - Frame Number The value contained in this register is the current SOF number. This value can be modified by software. • 7-0 - FLEN7:0 - Frame Length The value contained the data frame length transmited. 24.16.2 USB Host Pipe registers • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2-0 - PNUM2:0 - Pipe Number Select the pipe using this register. The USB Host registers ended by a X correspond then to this number. This number is used for the USB controller following the value of the PNUMD bit. Bit 7 6 5 4 3 2 1 0 - - - - - FNUM10 FNUM9 FNUM8 UHFNUMH Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 FNUM7 FNUM6 FNUM5 FNUM4 FNUM3 FNUM2 FNUM1 FNUM0 UHFNUML Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 FLEN7 FLEN6 FLEN5 FLEN4 FLEN3 FLEN2 FLEN1 FLEN0 UHFLEN Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 PNUM2 PNUM1 PNUM0 UPNUM Read/write RW RW RW Initial value 0 0 0 0 0 0 0 0296 7593L–AVR–09/12 AT90USB64/128 • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6 - P6RST - Pipe 6 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 6. • 5 - P5RST - Pipe 5 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 5. • 4 - P4RST - Pipe 4 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 4. • 3 - P3RST - Pipe 3 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 3. • 2 - P2RST - Pipe 2 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 2. • 1 - P1RST - Pipe 1 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 1. • 0 - P0RST - Pipe 0 Reset Set this bit to 1 and reset this bit to 0 to reset the Pipe 0. • 7 - Reserved The value read from this bit is always 0. Do not set this bit. • 6 - PFREEZE - Pipe Freeze Set this bit to Freeze the Pipe requests generation. Clear this bit to enable the Pipe request generation. This bit is set by hardware when: - the pipe is not configured - a STALL handshake has been received on this Pipe - An error occurs on the Pipe (UPINTX.PERRI = 1) - (INRQ+1) In requests have been processed This bit is set at 1 by hardware after a Pipe reset or a Pipe enable. Bit 7 6 5 4 3 2 1 0 - P6RST P5RST P4RST P3RST P2RST P1RST P0RST UPRST Read/write RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - PFREEZE INMODE - RSTDT - - PEN UPCONX Read/write RW RW RW RW Initial value 0 0 0 0 0 0 0 0297 7593L–AVR–09/12 AT90USB64/128 • 5 - INMODE - IN Request mode Set this bit to allow the USB controller to perform infinite IN requests when the Pipe is not frozen. Clear this bit to perform a pre-defined number of IN requests. This number is stored in the UINRQX register. • 4 - Reserved The value read from this bit is always 0. Do not set this bit. • 3 - RSTDT - Reset Data Toggle Set this bit to reset the Data Toggle to its initial value for the current Pipe. Cleared by hardware when proceed. Clearing by software has no effect. • 2 - Reserved The value read from these bits is always 0. Do not set these bits. • 1 - Reserved The value read from these bits is always 0. Do not set these bits. • 0 - PEN - Pipe Enable Set to enable the Pipe. Clear to disable and set the pipe. • 7-6 - PTYPE1:0 - Pipe Type Select the type of the Pipe: - 00: Control - 01: Isochronous - 10: Bulk - 11: Interrupt • 5-4 - PTOKEN1:0 - Pipe Token Select the Token to associate to the Pipe - 00: SETUP - 01: IN - 10: OUT - 11: reserved • 3-0 - PEPNUM3:0 - Pipe Endpoint Number Set this field according to the Pipe configuration. Set the number of the Endpoint targeted by the Pipe. This value is from 0 and 15. Bit 7 6 5 4 3 2 1 0 PTYPE1 PTYPE0 PTOKEN1 PTOKEN0 PEPNUM3 PEPNUM2 PEPNUM1 PEPNUM0 UPCFG0X Read/write RW RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0298 7593L–AVR–09/12 AT90USB64/128 • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6-4 - PSIZE2:0 - Pipe Size Select the size of the Pipe: - 000: 8 - 100: 128 (only for endpoint 1) - 001: 16 - 101: 256 (only for endpoint 1) - 010: 32 - 110: Reserved. Do not use this configuration. - 011: 64 - 111: Reserved. Do not use this configuration. • 3-2 - PBK1:0 - Pipe Bank Select the number of bank to declare for the current Pipe. - 00: 1 bank - 01: 2 banks - 10: invalid - 11: invalid • ALLOC - Configure Pipe Memory Set to configure the pipe memory with the characteristics. Clear to update the memory allocation. Refer to the Memory Management chapter for more details. 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 7 - INTFRQ7:0 - Interrupt Pipe Request Frequency These bits are the maximum value in millisecond of the polling period for an Interrupt Pipe. This value has no effect for a non-Interrupt Pipe. Bit 7 6 5 4 3 2 1 0 - PSIZE2:0 PBK1:0 ALLOC - UPCFG1X Read/write R RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 INTFRQ7 INTFRQ6 INTFRQ5 INTFRQ4 INTFRQ3 INTFRQ2 INTFRQ1 INTFRQ0 UPCFG2X Read/write RW RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0299 7593L–AVR–09/12 AT90USB64/128 • 7 - CFGOK - Configure Pipe Memory OK Set by hardware if the required memory configuration has been successfully performed. Cleared by hardware when the pipe is disabled. The USB reset and the reset pipe have no effect on the configuration of the pipe. • 6 - OVERFI - Overflow Set by hardware when a the current Pipe has received more data than the maximum length of the current Pipe. An interrupt is triggered if the FLERRE bit is set. Shall be cleared by software. Setting by software has no effect. • 5 - UNDERFI - Underflow Set by hardware when a transaction underflow occurs in the current isochronous or interrupt Pipe. The Pipe can’t send the data flow required by the device. A ZLP will be sent instead. An interrupt is triggered if the FLERRE bit is set. Shall be cleared by software. Setting by software has no effect. Note: the Host controller has to send a OUT packet, but the bank is empty. A ZLP will be sent and the UNDERFI bit is set. • 4 - Reserved The value read from these bits is always 0. Do not set these bits. • 3-2 - DTSEQ1:0 - Toggle Sequencing flag Set by hardware to indicate the PID data of the current bank: 00b Data0 01b Data1 1xb Reserved. For OUT Pipe, this value indicates the next data toggle that will be sent. This is not relative to the current bank. For IN Pipe, this value indicates the last data toggle received on the current bank. • 1-0 - NBUSYBK1:0 - Busy Bank flag Set by hardware to indicate the number of busy bank. For OUT Pipe, it indicates the number of busy bank(s), filled by the user, ready for OUT transfer. For IN Pipe, it indicates the number of busy bank(s) filled by IN transaction from the Device. 00b All banks are free 01b 1 busy bank 10b 2 busy banks 11b Reserved. Bit 7 6 5 4 3 2 1 0 CFGOK OVERFI UNDERFI - DTSEQ1:0 NBUSYBK UPSTAX Read/write R RW RW R R R R Initial value 0 0 0 0 0 0 0 0300 7593L–AVR–09/12 AT90USB64/128 • 7-0 - INRQ7:0 - IN Request Number Before Freeze Enter the number of IN transactions before the USB controller freezes the pipe. The USB controller will perform (INRQ+1) IN requests before to freeze the Pipe. This counter is automatically decreased by 1 each time a IN request has been successfully performed. This register has no effect when the INMODE bit is set (infinite IN requests generation till the pipe is not frozen). • 7-6 - Reserved The value read from these bits is always 0. Do not set these bits. • 5 - COUNTER1:0 - Error counter This counter is increased by the USB controller each time an error occurs on the Pipe. When this value reaches 3, the Pipe is automatically frozen. Clear these bits by software. • 4 - CRC16 - CRC16 Error Set by hardware when a CRC16 error has been detected. Shall be cleared by software. Setting by software has no effect. • 3 - TIMEOUT - Time-out Error Set by hardware when a time-out error has been detected. Shall be cleared by software. Setting by software has no effect. • 2 - PID - PID Error Set by hardware when a PID error has been detected. Shall be cleared by software. Setting by software has no effect. • 1 - DATAPID - Data PID Error Set by hardware when a data PID error has been detected. Shall be cleared by software. Setting by software has no effect. • 0 - DATATGL - Bad Data Toggle Set by hardware when a data toggle error has been detected. Shall be cleared by software. Setting by software has no effect. Bit 7 6 5 4 3 2 1 0 INRQ7 INRQ6 INRQ5 INRQ4 INRQ3 INRQ2 INRQ1 INRQ0 UPINRQX Read/write RW RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - COUNTER1:0 CRC16 TIMEOUT PID DATAPID DATATGL UPERRX Read/write RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0301 7593L–AVR–09/12 AT90USB64/128 • 7 - FIFOCON - FIFO Control For OUT and SETUP Pipe: Set by hardware when the current bank is free, at the same time than TXOUT or TXSTP. Clear to send the FIFO data and to switch the bank. Setting by software has no effect. For IN Pipe: Set by hardware when a new IN message is stored in the current bank, at the same time than RXIN. Clear to free the current bank and to switch to the following bank. Setting by software has no effect. • 6 - NAKEDI - NAK Handshake received Set by hardware when a NAK has been received on the current bank of the Pipe. This triggers an interrupt if the NAKEDE bit is set in the UPIENX register. Shall be clear to handshake the interrupt. Setting by software has no effect. • 5 - RWAL - Read/Write Allowed OUT Pipe: Set by hardware when the firmware can write a new data into the Pipe FIFO. Cleared by hardware when the current Pipe FIFO is full. IN Pipe: Set by hardware when the firmware can read a new data into the Pipe FIFO. Cleared by hardware when the current Pipe FIFO is empty. This bit is also cleared by hardware when the RXSTALL or the PERR bit is set • 4 - PERRI -PIPE Error Set by hardware when an error occurs on the current bank of the Pipe. This triggers an interrupt if the PERRE bit is set in the UPIENX register. Refers to the UPERRX register to determine the source of the error. Automatically cleared by hardware when the error source bit is cleared. • 3 - TXSTPI - SETUP Bank ready Set by hardware when the current SETUP bank is free and can be filled. This triggers an interrupt if the TXSTPE bit is set in the UPIENX register. Shall be cleared to handshake the interrupt. Setting by software has no effect. • 2 - TXOUTI -OUT Bank ready Set by hardware when the current OUT bank is free and can be filled. This triggers an interrupt if the TXOUTE bit is set in the UPIENX register. Shall be cleared to handshake the interrupt. Setting by software has no effect. Bit 7 6 5 4 3 2 1 0 FIFOCON NAKEDI RWAL PERRI TXSTPI TXOUTI RXSTALLI RXINI UPINTX Read/write RW RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0302 7593L–AVR–09/12 AT90USB64/128 • 1 - RXSTALLI / CRCERR - STALL Received / Isochronous CRC Error Set by hardware when a STALL handshake has been received on the current bank of the Pipe. The Pipe is automatically frozen. This triggers an interrupt if the RXSTALLE bit is set in the UPIENX register. Shall be cleared to handshake the interrupt. Setting by software has no effect. For Isochronous Pipe: Set by hardware when a CRC error occurs on the current bank of the Pipe. This triggers an interrupt if the TXSTPE bit is set in the UPIENX register. Shall be cleared to handshake the interrupt. Setting by software has no effect. • 0 - RXINI - IN Data received Set by hardware when a new USB message is stored in the current bank of the Pipe. This triggers an interrupt if the RXINE bit is set in the UPIENX register. Shall be cleared to handshake the interrupt. Setting by software has no effect. • 7 - FLERRE - Flow Error Interrupt enable Set to enable the OVERFI and UNDERFI interrupts. Clear to disable the OVERFI and UNDERFI interrupts. • 6 - NAKEDE -NAK Handshake Received Interrupt Enable Set to enable the NAKEDI interrupt. Clear to disable the NAKEDI interrupt. • 5 - Reserved The value read from these bits is always 0. Do not set these bits. • 4 - PERRE -PIPE Error Interrupt Enable Set to enable the PERRI interrupt. Clear to disable the PERRI interrupt. • 3 - TXSTPE - SETUP Bank ready Interrupt Enable Set to enable the TXSTPI interrupt. Clear to disable the TXSTPI interrupt. • 2 - TXOUTE - OUT Bank ready Interrupt Enable Set to enable the TXOUTI interrupt. Clear to disable the TXOUTI interrupt. • 1 - RXSTALLE - STALL Received Interrupt Enable Set to enable the RXSTALLI interrupt. Clear to disable the RXSTALLI interrupt. Bit 7 6 5 4 3 2 1 0 FLERRE NAKEDE - PERRE TXSTPE TXOUTE RXSTALLE RXINE UPIENX Read/write RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0303 7593L–AVR–09/12 AT90USB64/128 • 0 - RXINE - IN Data received Interrupt Enable Set to enable the RXINI interrupt. Clear to disable the RXINI interrupt. • 7-0 - PDAT7:0 - Pipe Data bits Set by the software to read/write a byte from/to the Pipe FIFO selected by PNUM. • 7-3 - Reserved The value read from these bits is always 0. Do not set these bits. • 2-0 - PBYCT10:8 - Byte count (high) bits Set by hardware. This field is the MSB of the byte count of the FIFO endpoint. The LSB part is provided by the UPBCLX register. • 7-0 - PBYCT7:0 - Byte Count (low) bits Set by the hardware. PBYCT10:0 is: - (for OUT Pipe) increased after each writing into the Pipe and decremented after each byte sent, - (for IN Pipe) increased after each byte received by the host, and decremented after each byte read by the software. • 7 - Reserved The value read from these bits is always 0. Do not set these bits. • 6-0 - PINT6:0 - Pipe Interrupts bits Set by hardware when an interrupt is triggered by the UPINTX register and if the corresponding endpoint interrupt enable bit is set. Cleared by hardware when the interrupt source is served. Bit 7 6 5 4 3 2 1 0 PDAT7 PDAT6 PDAT5 PDAT4 PDAT3 PDAT2 PDAT1 PDAT0 UPDATX Read/write RW RW RW RW RW RW RW RW Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - - - - - PBYCT10 PBYCT9 PBYCT8 UPBCHX Read/write R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 PBYCT7 PBYCT6 PBYCT5 PBYCT4 PBYCT3 PBYCT2 PBYCT1 PBYCT0 UPBCLX Read/write R R R R R R R R Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 - PINT6 PINT5 PINT4 PINT3 PINT2 PINT1 PINT0 UPINT Read/write Initial value 0 0 0 0 0 0 0 0304 7593L–AVR–09/12 AT90USB64/128 25. Analog Comparator The Analog Comparator compares the input values on the positive pin AIN0 and negative pin AIN1. When the voltage on the positive pin AIN0 is higher than the voltage on the negative pin AIN1, the Analog Comparator output, ACO, is set. The comparator’s output can be set to trigger the Timer/Counter1 Input Capture function. In addition, the comparator can trigger a separate interrupt, exclusive to the Analog Comparator. The user can select Interrupt triggering on comparator output rise, fall or toggle. A block diagram of the comparator and its surrounding logic is shown in Figure 25-1. The Power Reduction ADC bit, PRADC, in “PRR0 – Power Reduction Register 0” on page 54 must be disabled by writing a logical zero to be able to use the ADC input MUX. Figure 25-1. Analog Comparator block diagram (2). Notes: 1. See Table 25-2 on page 306. 2. Refer to Figure 1-1 on page 3 and Table 11-6 on page 79 for Analog Comparator pin placement. 25.0.1 ADCSRB – ADC Control and Status Register B • Bit 6 – ACME: Analog Comparator Multiplexer Enable When this bit is written logic one and the ADC is switched off (ADEN in ADCSRA is zero), the ADC multiplexer selects the negative input to the Analog Comparator. When this bit is written logic zero, AIN1 is applied to the negative input of the Analog Comparator. For a detailed description of this bit, see “Analog Comparator multiplexed input” on page 306. 25.0.2 ACSR – Analog Comparator Control and Status Register ACBG BANDGAP REFERENCE ADC MULTIPLEXER OUTPUT ACME ADEN (1) Bit 7 6 5 4 3 2 1 0 – ACME – – - ADTS2 ADTS1 ADTS0 ADCSRB Read/write R R/W R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 ACSR Read/write R/W R/W R R/W R/W R/W R/W R/W Initial value 0 0 N/A 0 0 0 0 0305 7593L–AVR–09/12 AT90USB64/128 • Bit 7 – ACD: Analog Comparator Disable When this bit is written logic one, the power to the Analog Comparator is switched off. This bit can be set at any time to turn off the Analog Comparator. This will reduce power consumption in Active and Idle mode. When changing the ACD bit, the Analog Comparator Interrupt must be disabled by clearing the ACIE bit in ACSR. Otherwise an interrupt can occur when the bit is changed. • Bit 6 – ACBG: Analog Comparator Bandgap Select When this bit is set, a fixed bandgap reference voltage replaces the positive input to the Analog Comparator. When this bit is cleared, AIN0 is applied to the positive input of the Analog Comparator. See “Internal voltage reference” on page 62. • Bit 5 – ACO: Analog Comparator Output The output of the Analog Comparator is synchronized and then directly connected to ACO. The synchronization introduces a delay of 1 - 2 clock cycles. • Bit 4 – ACI: Analog Comparator Interrupt Flag This bit is set by hardware when a comparator output event triggers the interrupt mode defined by ACIS1 and ACIS0. The Analog Comparator interrupt routine is executed if the ACIE bit is set and the I-bit in SREG is set. ACI is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, ACI is cleared by writing a logic one to the flag. • Bit 3 – ACIE: Analog Comparator Interrupt Enable When the ACIE bit is written logic one and the I-bit in the Status Register is set, the Analog Comparator interrupt is activated. When written logic zero, the interrupt is disabled. • Bit 2 – ACIC: Analog Comparator Input Capture Enable When written logic one, this bit enables the input capture function in Timer/Counter1 to be triggered by the Analog Comparator. The comparator output is in this case directly connected to the input capture front-end logic, making the comparator utilize the noise canceler and edge select features of the Timer/Counter1 Input Capture interrupt. When written logic zero, no connection between the Analog Comparator and the input capture function exists. To make the comparator trigger the Timer/Counter1 Input Capture interrupt, the ICIE1 bit in the Timer Interrupt Mask Register (TIMSK1) must be set. • Bits 1, 0 – ACIS1, ACIS0: Analog Comparator Interrupt Mode Select These bits determine which comparator events that trigger the Analog Comparator interrupt. The different settings are shown in Table 25-1. When changing the ACIS1/ACIS0 bits, the Analog Comparator Interrupt must be disabled by clearing its Interrupt Enable bit in the ACSR Register. Otherwise an interrupt can occur when the bits are changed. Table 25-1. ACIS1/ACIS0 settings. ACIS1 ACIS0 Interrupt mode 0 0 Comparator Interrupt on Output Toggle 0 1 Reserved 1 0 Comparator Interrupt on Falling Output Edge 1 1 Comparator Interrupt on Rising Output Edge306 7593L–AVR–09/12 AT90USB64/128 25.1 Analog Comparator multiplexed input It is possible to select any of the ADC7..0 pins to replace the negative input to the Analog Comparator. The ADC multiplexer is used to select this input, and consequently, the ADC must be switched off to utilize this feature. If the Analog Comparator Multiplexer Enable bit (ACME in ADCSRB) is set and the ADC is switched off (ADEN in ADCSRA is zero), and MUX2..0 in ADMUX select the input pin to replace the negative input to the Analog Comparator, as shown in Table 25-2. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the Analog Comparator. 25.1.1 DIDR1 – Digital Input Disable Register 1 • Bit 1, 0 – AIN1D, AIN0D: AIN1, AIN0 Digital Input Disable When this bit is written logic one, the digital input buffer on the AIN1/0 pin is disabled. The corresponding PIN Register bit will always read as zero when this bit is set. When an analog signal is applied to the AIN1/0 pin and the digital input from this pin is not needed, this bit should be written logic one to reduce power consumption in the digital input buffer. Table 25-2. Analog Comparator multiplexed input. ACME ADEN MUX2..0 Analog Comparator negative input 0 x xxx AIN1 1 1 xxx AIN1 1 0 000 ADC0 1 0 001 ADC1 1 0 010 ADC2 1 0 011 ADC3 1 0 100 ADC4 1 0 101 ADC5 1 0 110 ADC6 1 0 111 ADC7 Bit 7 6 5 4 3 2 1 0 – – – – – – AIN1D AIN0D DIDR1 Read/write R R R R R R R/W R/W Initial value 0 0 0 0 0 0 0 0307 7593L–AVR–09/12 AT90USB64/128 26. ADC – Analog to Digital Converter 26.1 Features • 10-bit resolution • 0.5 LSB integral non-linearity • ±2 LSB absolute accuracy • 65 - 260µs conversion time • Up to 15ksps at maximum resolution • Eight multiplexed single ended input channels • Seven differential input channels • Optional left adjustment for ADC result readout • 0 - VCC ADC input voltage range • Selectable 2.56V ADC reference voltage • Free running or single conversion mode • ADC start conversion by auto triggering on interrupt sources • Interrupt on ADC conversion complete • Sleep mode noise canceler 26.2 Overview The Atmel AT90USB64/128 features a 10-bit successive approximation ADC. The ADC is connected to an 8-channel Analog Multiplexer which allows eight single-ended voltage inputs constructed from the pins of Port F. The single-ended voltage inputs refer to 0V (GND). The device also supports 16 differential voltage input combinations. Two of the differential inputs (ADC1, ADC0 and ADC3, ADC2) are equipped with a programmable gain stage, providing amplification steps of 0 dB (1×), 20 dB (10×), or 46 dB (200×) on the differential input voltage before the A/D conversion. Seven differential analog input channels share a common negative terminal (ADC1), while any other ADC input can be selected as the positive input terminal. If 1× or 10× gain is used, 8-bit resolution can be expected. If 200× gain is used, 7-bit resolution can be expected. The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is held at a constant level during conversion. A block diagram of the ADC is shown in Figure 26-1 on page 308. The ADC has a separate analog supply voltage pin, AVCC. AVCC must not differ more than ±0.3V from VCC. See the paragraph “ADC noise canceler” on page 314 on how to connect this pin. Internal reference voltages of nominally 2.56V or AVCC are provided on-chip. The voltage reference may be externally decoupled at the AREF pin by a capacitor for better noise performance.308 7593L–AVR–09/12 AT90USB64/128 Figure 26-1. Analog to digital converter block schematic. ADC CONVERSION COMPLETE IRQ 8-BIT DATA BUS 15 0 ADC MULTIPLEXER SELECT (ADMUX) ADC CTRL. & STATUS REGISTER (ADCSRA) ADC DATA REGISTER (ADCH/ADCL) MUX2 ADIE ADATE ADEN ADSC ADIF ADIF MUX1 MUX0 ADPS2 ADPS1 ADPS0 MUX3 CONVERSION LOGIC 10-BIT DAC + - SAMPLE & HOLD COMPARATOR INTERNAL REFERENCE MUX DECODER MUX4 AVCC ADC7 ADC6 ADC5 ADC4 ADC3 ADC2 ADC1 ADC0 REFS1 REFS0 ADLAR + - CHANNEL SELECTION GAIN SELECTION ADC[9:0] ADC MULTIPLEXER OUTPUT DIFFERENTIAL AMPLIFIER AREF BANDGAP REFERENCE PRESCALER SINGLE ENDED / DIFFERENTIAL SELECTION GND POS. INPUT MUX NEG. INPUT MUX TRIGGER SELECT ADTS[2:0] INTERRUPT FLAGS ADHSM START309 7593L–AVR–09/12 AT90USB64/128 26.3 Operation The ADC converts an analog input voltage to a 10-bit digital value through successive approximation. The minimum value represents GND and the maximum value represents the voltage on the AREF pin minus 1 LSB. Optionally, AVCC or an internal 2.56V reference voltage may be connected to the AREF pin by writing to the REFSn bits in the ADMUX Register. The internal voltage reference may thus be decoupled by an external capacitor at the AREF pin to improve noise immunity. The analog input channel and differential gain are selected by writing to the MUX bits in ADMUX. Any of the ADC input pins, as well as GND and a fixed bandgap voltage reference, can be selected as single ended inputs to the ADC. A selection of ADC input pins can be selected as positive and negative inputs to the differential amplifier. The ADC is enabled by setting the ADC Enable bit, ADEN in ADCSRA. Voltage reference and input channel selections will not go into effect until ADEN is set. The ADC does not consume power when ADEN is cleared, so it is recommended to switch off the ADC before entering power saving sleep modes. The ADC generates a 10-bit result which is presented in the ADC Data Registers, ADCH and ADCL. By default, the result is presented right adjusted, but can optionally be presented left adjusted by setting the ADLAR bit in ADMUX. If the result is left adjusted and no more than 8-bit precision is required, it is sufficient to read ADCH. Otherwise, ADCL must be read first, then ADCH, to ensure that the content of the Data Registers belongs to the same conversion. Once ADCL is read, ADC access to Data Registers is blocked. This means that if ADCL has been read, and a conversion completes before ADCH is read, neither register is updated and the result from the conversion is lost. When ADCH is read, ADC access to the ADCH and ADCL Registers is re-enabled. The ADC has its own interrupt which can be triggered when a conversion completes. The ADC access to the Data Registers is prohibited between reading of ADCH and ADCL, the interrupt will trigger even if the result is lost. 26.4 Starting a conversion A single conversion is started by writing a logical one to the ADC Start Conversion bit, ADSC. This bit stays high as long as the conversion is in progress and will be cleared by hardware when the conversion is completed. If a different data channel is selected while a conversion is in progress, the ADC will finish the current conversion before performing the channel change. Alternatively, a conversion can be triggered automatically by various sources. Auto Triggering is enabled by setting the ADC Auto Trigger Enable bit, ADATE in ADCSRA. The trigger source is selected by setting the ADC Trigger Select bits, ADTS in ADCSRB (See description of the ADTS bits for a list of the trigger sources). When a positive edge occurs on the selected trigger signal, the ADC prescaler is reset and a conversion is started. This provides a method of starting conversions at fixed intervals. If the trigger signal is still set when the conversion completes, a new conversion will not be started. If another positive edge occurs on the trigger signal during conversion, the edge will be ignored. Note that an interrupt flag will be set even if the specific interrupt is disabled or the Global Interrupt Enable bit in SREG is cleared. A conversion can thus be triggered without causing an interrupt. However, the interrupt flag must be cleared in order to trigger a new conversion at the next interrupt event. 310 7593L–AVR–09/12 AT90USB64/128 Figure 26-2. ADC auto trigger logic. Using the ADC Interrupt Flag as a trigger source makes the ADC start a new conversion as soon as the ongoing conversion has finished. The ADC then operates in Free Running mode, constantly sampling and updating the ADC Data Register. The first conversion must be started by writing a logical one to the ADSC bit in ADCSRA. In this mode the ADC will perform successive conversions independently of whether the ADC Interrupt Flag, ADIF is cleared or not. If Auto Triggering is enabled, single conversions can be started by writing ADSC in ADCSRA to one. ADSC can also be used to determine if a conversion is in progress. The ADSC bit will be read as one during a conversion, independently of how the conversion was started. 26.5 Prescaling and conversion timing Figure 26-3. ADC prescaler. By default, the successive approximation circuitry requires an input clock frequency between 50kHz and 200kHz to get maximum resolution. If a lower resolution than 10 bits is needed, the input clock frequency to the ADC can be higher than 200kHz to get a higher sample rate. Alternatively, setting the ADHSM bit in ADCSRB allows an increased ADC clock frequency at the expense of higher power consumption. The ADC module contains a prescaler, which generates an acceptable ADC clock frequency from any CPU frequency above 100kHz. The prescaling is set by the ADPS bits in ADCSRA. The prescaler starts counting from the moment the ADC is switched on by setting the ADEN bit ADSC ADIF SOURCE 1 SOURCE n ADTS[2:0] CONVERSION LOGIC PRESCALER START CLKADC . . . . EDGE DETECTOR ADATE 7-BIT ADC PRESCALER ADC CLOCK SOURCE CK ADPS0 ADPS1 ADPS2 CK/128 CK/2 CK/4 CK/8 CK/16 CK/32 CK/64 Reset ADEN START311 7593L–AVR–09/12 AT90USB64/128 in ADCSRA. The prescaler keeps running for as long as the ADEN bit is set, and is continuously reset when ADEN is low. When initiating a single ended conversion by setting the ADSC bit in ADCSRA, the conversion starts at the following rising edge of the ADC clock cycle. See “Differential channels” on page 312 for details on differential conversion timing. A normal conversion takes 13 ADC clock cycles. The first conversion after the ADC is switched on (ADEN in ADCSRA is set) takes 25 ADC clock cycles in order to initialize the analog circuitry. The actual sample-and-hold takes place 1.5 ADC clock cycles after the start of a normal conversion and 13.5 ADC clock cycles after the start of an first conversion. When a conversion is complete, the result is written to the ADC Data Registers, and ADIF is set. In Single Conversion mode, ADSC is cleared simultaneously. The software may then set ADSC again, and a new conversion will be initiated on the first rising ADC clock edge. When Auto Triggering is used, the prescaler is reset when the trigger event occurs. This assures a fixed delay from the trigger event to the start of conversion. In this mode, the sample-and-hold takes place two ADC clock cycles after the rising edge on the trigger source signal. Three additional CPU clock cycles are used for synchronization logic. In Free Running mode, a new conversion will be started immediately after the conversion completes, while ADSC remains high. For a summary of conversion times, see Table 26-1 on page 312. Figure 26-4. ADC timing diagram, first conversion (single conversion mode). Figure 26-5. ADC timing diagram, single conversion. Sign and MSB of result LSB of result ADC clock ADSC Sample & hold ADIF ADCH ADCL Cycle number ADEN 1 2 12 13 14 15 16 17 18 19 20 21 22 23 24 25 1 2 First conversion Next conversion 3 MUX and REFS update MUX and REFS update Conversion complete 1 2 3 4 5 6 7 8 9 10 11 12 13 Sign and MSB of result LSB of result ADC clock ADSC ADIF ADCH ADCL Cycle number 1 2 One conversion Next conversion 3 Sample & hold MUX and REFS update Conversion complete MUX and REFS update312 7593L–AVR–09/12 AT90USB64/128 Figure 26-6. ADC timing diagram, auto triggered conversion. Figure 26-7. ADC timing diagram, free running conversion. 26.5.1 Differential channels When using differential channels, certain aspects of the conversion need to be taken into consideration. Differential conversions are synchronized to the internal clock CKADC2 equal to half the ADC clock frequency. This synchronization is done automatically by the ADC interface in such a way that the sample-and-hold occurs at a specific phase of CKADC2. A conversion initiated by the user (that is, all single conversions, and the first free running conversion) when CKADC2 is low will take the same amount of time as a single ended conversion (13 ADC clock cycles from the next prescaled clock cycle). A conversion initiated by the user when CKADC2 is high will take 14 ADC clock cycles due to the synchronization mechanism. In Free Running mode, a new conversion is initiated immediately after the previous conversion completes, and since CKADC2 is high at this time, all automatically started (that is, all but the first) Free Running conversions will take 14 ADC clock cycles. Table 26-1. ADC conversion time. Condition First conversion Normal conversion, single ended Auto triggered conversion Sample & Hold (Cycles from Start of Conversion) 14.5 1.5 2 Conversion Time (Cycles) 25 13 13.5 1 2 3 4 5 6 7 8 9 10 11 12 13 Sign and MSB of result LSB of result ADC clock Trigger Source ADIF ADCH ADCL Cycle number 1 2 One conversion Next conversion Conversion complete Prescaler reset ADATE Prescaler reset Sample & hold MUX and REFS update 11 12 13 Sign and MSB of result LSB of result ADC clock ADSC ADIF ADCH ADCL Cycle number 1 2 One conversion Next conversion 3 4 Conversion complete Sample & hold MUX and REFS update313 7593L–AVR–09/12 AT90USB64/128 If differential channels are used and conversions are started by Auto Triggering, the ADC must be switched off between conversions. When Auto Triggering is used, the ADC prescaler is reset before the conversion is started. Since the stage is dependent of a stable ADC clock prior to the conversion, this conversion will not be valid. By disabling and then re-enabling the ADC between each conversion (writing ADEN in ADCSRA to “0” then to “1”), only extended conversions are performed. The result from the extended conversions will be valid. See “Prescaling and conversion timing” on page 310 for timing details. The gain stage is optimized for a bandwidth of 4kHz at all gain settings. Higher frequencies may be subjected to non-linear amplification. An external low-pass filter should be used if the input signal contains higher frequency components than the gain stage bandwidth. Note that the ADC clock frequency is independent of the gain stage bandwidth limitation. For example, the ADC clock period may be 6µs, allowing a channel to be sampled at 12ksps, regardless of the bandwidth of this channel. 26.6 Changing channel or reference selection The MUXn and REFS1:0 bits in the ADMUX Register are single buffered through a temporary register to which the CPU has random access. This ensures that the channels and reference selection only takes place at a safe point during the conversion. The channel and reference selection is continuously updated until a conversion is started. Once the conversion starts, the channel and reference selection is locked to ensure a sufficient sampling time for the ADC. Continuous updating resumes in the last ADC clock cycle before the conversion completes (ADIF in ADCSRA is set). Note that the conversion starts on the following rising ADC clock edge after ADSC is written. The user is thus advised not to write new channel or reference selection values to ADMUX until one ADC clock cycle after ADSC is written. If Auto Triggering is used, the exact time of the triggering event can be indeterministic. Special care must be taken when updating the ADMUX Register, in order to control which conversion will be affected by the new settings. If both ADATE and ADEN is written to one, an interrupt event can occur at any time. If the ADMUX Register is changed in this period, the user cannot tell if the next conversion is based on the old or the new settings. ADMUX can be safely updated in the following ways: a. When ADATE or ADEN is cleared. b. During conversion, minimum one ADC clock cycle after the trigger event. c. After a conversion, before the interrupt flag used as trigger source is cleared. When updating ADMUX in one of these conditions, the new settings will affect the next ADC conversion. Special care should be taken when changing differential channels. Once a differential channel has been selected, the stage may take as much as 125µs to stabilize to the new value. Thus conversions should not be started within the first 125µs after selecting a new differential channel. Alternatively, conversion results obtained within this period should be discarded. The same settling time should be observed for the first differential conversion after changing ADC reference (by changing the REFS1:0 bits in ADMUX). The settling time and gain stage bandwidth is independent of the ADHSM bit setting.314 7593L–AVR–09/12 AT90USB64/128 26.6.1 ADC input channels When changing channel selections, the user should observe the following guidelines to ensure that the correct channel is selected: • In Single Conversion mode, always select the channel before starting the conversion. The channel selection may be changed one ADC clock cycle after writing one to ADSC. However, the simplest method is to wait for the conversion to complete before changing the channel selection • In Free Running mode, always select the channel before starting the first conversion. The channel selection may be changed one ADC clock cycle after writing one to ADSC. However, the simplest method is to wait for the first conversion to complete, and then change the channel selection. Since the next conversion has already started automatically, the next result will reflect the previous channel selection. Subsequent conversions will reflect the new channel selection When switching to a differential gain channel, the first conversion result may have a poor accuracy due to the required settling time for the automatic offset cancellation circuitry. The user should preferably disregard the first conversion result. 26.6.2 ADC voltage reference The reference voltage for the ADC (VREF) indicates the conversion range for the ADC. Single ended channels that exceed VREF will result in codes close to 0x3FF. VREF can be selected as either AVCC, internal 2.56V reference, or external AREF pin. AVCC is connected to the ADC through a passive switch. The internal 2.56V reference is generated from the internal bandgap reference (VBG) through an internal amplifier. In either case, the external AREF pin is directly connected to the ADC, and the reference voltage can be made more immune to noise by connecting a capacitor between the AREF pin and ground. VREF can also be measured at the AREF pin with a high impedant voltmeter. Note that VREF is a high impedant source, and only a capacitive load should be connected in a system. If the user has a fixed voltage source connected to the AREF pin, the user may not use the other reference voltage options in the application, as they will be shorted to the external voltage. If no external voltage is applied to the AREF pin, the user may switch between AVCC and 2.56V as reference selection. The first ADC conversion result after switching reference voltage source may be inaccurate, and the user is advised to discard this result. If differential channels are used, the selected reference should not be closer to AVCC than indicated in Table 31-5 on page 397. 26.7 ADC noise canceler The ADC features a noise canceler that enables conversion during sleep mode to reduce noise induced from the CPU core and other I/O peripherals. The noise canceler can be used with ADC Noise Reduction and Idle mode. To make use of this feature, the following procedure should be used:315 7593L–AVR–09/12 AT90USB64/128 a. Make sure that the ADC is enabled and is not busy converting. Single Conversion mode must be selected and the ADC conversion complete interrupt must be enabled. b. Enter ADC Noise Reduction mode (or Idle mode). The ADC will start a conversion once the CPU has been halted. c. If no other interrupts occur before the ADC conversion completes, the ADC interrupt will wake up the CPU and execute the ADC Conversion Complete interrupt routine. If another interrupt wakes up the CPU before the ADC conversion is complete, that interrupt will be executed, and an ADC Conversion Complete interrupt request will be generated when the ADC conversion completes. The CPU will remain in active mode until a new sleep command is executed. Note that the ADC will not be automatically turned off when entering other sleep modes than Idle mode and ADC Noise Reduction mode. The user is advised to write zero to ADEN before entering such sleep modes to avoid excessive power consumption. If the ADC is enabled in such sleep modes and the user wants to perform differential conversions, the user is advised to switch the ADC off and on after waking up from sleep to prompt an extended conversion to get a valid result. 26.7.1 Analog input circuitry The analog input circuitry for single ended channels is illustrated in Figure 26-8. An analog source applied to ADCn is subjected to the pin capacitance and input leakage of that pin, regardless of whether that channel is selected as input for the ADC. When the channel is selected, the source must drive the S/H capacitor through the series resistance (combined resistance in the input path). The ADC is optimized for analog signals with an output impedance of approximately 10kΩ or less. If such a source is used, the sampling time will be negligible. If a source with higher impedance is used, the sampling time will depend on how long time the source needs to charge the S/H capacitor, with can vary widely. The user is recommended to only use low impedant sources with slowly varying signals, since this minimizes the required charge transfer to the S/H capacitor. If differential gain channels are used, the input circuitry looks somewhat different, although source impedances of a few hundred kΩ or less is recommended. Signal components higher than the Nyquist frequency (fADC/2) should not be present for either kind of channels, to avoid distortion from unpredictable signal convolution. The user is advised to remove high frequency components with a low-pass filter before applying the signals as inputs to the ADC. Figure 26-8. Analog input circuitry. ADCn I IH 1..100kΩ CS/H= 14pF VCC/2 I IL316 7593L–AVR–09/12 AT90USB64/128 26.7.2 Analog noise canceling techniques Digital circuitry inside and outside the device generates EMI which might affect the accuracy of analog measurements. If conversion accuracy is critical, the noise level can be reduced by applying the following techniques: a. Keep analog signal paths as short as possible. Make sure analog tracks run over the analog ground plane, and keep them well away from high-speed switching digital tracks. b. The AVCC pin on the device should be connected to the digital VCC supply voltage via an LC network as shown in Figure 26-9. c. Use the ADC noise canceler function to reduce induced noise from the CPU. d. If any ADC port pins are used as digital outputs, it is essential that these do not switch while a conversion is in progress. Figure 26-9. ADC power connections. 26.7.3 Offset compensation schemes The gain stage has a built-in offset cancellation circuitry that nulls the offset of differential measurements as much as possible. The remaining offset in the analog path can be measured directly by selecting the same channel for both differential inputs. This offset residue can be then subtracted in software from the measurement results. Using this kind of software based offset correction, offset on any channel can be reduced below one LSB. 26.7.4 ADC accuracy definitions An n-bit single-ended ADC converts a voltage linearly between GND and VREF in 2n steps (LSBs). The lowest code is read as 0, and the highest code is read as 2n -1. Several parameters describe the deviation from the ideal behavior: VCC GND 100nF Analog ground plane (ADC0) PF0 (ADC7) PF7 (ADC1) PF1 (ADC2) PF2 (ADC3) PF3 (ADC4) PF4 (ADC5) PF5 (ADC6) PF6 AREF GND AVCC 52 53 54 55 56 57 58 59 60 61 62 63 64 1 51 NC (AD0) PA0 10μH317 7593L–AVR–09/12 AT90USB64/128 • Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition (at 0.5 LSB). Ideal value: 0 LSB Figure 26-10. Offset error. • Gain Error: After adjusting for offset, the Gain Error is found as the deviation of the last transition (0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below maximum). Ideal value: 0 LSB Figure 26-11. Gain error. • Integral non-linearity (INL): After adjusting for offset and gain error, the INL is the maximum deviation of an actual transition compared to an ideal transition for any code. Ideal value: 0 LSB Output code VREF Input voltage Ideal ADC Actual ADC Offset error Output code VREF Input voltage Ideal ADC Actual ADC Gain error318 7593L–AVR–09/12 AT90USB64/128 Figure 26-12. Integral non-linearity (INL). • Differential Non-linearity (DNL): The maximum deviation of the actual code width (the interval between two adjacent transitions) from the ideal code width (1 LSB). Ideal value: 0 LSB Figure 26-13. Differential non-linearity (DNL). • Quantization Error: Due to the quantization of the input voltage into a finite number of codes, a range of input voltages (1 LSB wide) will code to the same value. Always ±0.5 LSB. • Absolute Accuracy: The maximum deviation of an actual (unadjusted) transition compared to an ideal transition for any code. This is the compound effect of offset, gain error, differential error, non-linearity, and quantization error. Ideal value: ±0.5 LSB. 26.8 ADC conversion result After the conversion is complete (ADIF is high), the conversion result can be found in the ADC Result Registers (ADCL, ADCH). Output code VREF Input voltage Ideal ADC Actual ADC INL Output code 0x3FF 0x000 0 VREF Input voltage DNL 1 LSB319 7593L–AVR–09/12 AT90USB64/128 For single ended conversion, the result is: where VIN is the voltage on the selected input pin and VREF the selected voltage reference (see Table 26-3 on page 322 and Table 26-4 on page 322). 0x000 represents analog ground, and 0x3FF represents the selected reference voltage minus one LSB. If differential channels are used, the result is: where VPOS is the voltage on the positive input pin, VNEG the voltage on the negative input pin, GAIN the selected gain factor and VREF the selected voltage reference. The result is presented in two’s complement form, from 0x200 (-512d) through 0x1FF (+511d). Note that if the user wants to perform a quick polarity check of the result, it is sufficient to read the MSB of the result (ADC9 in ADCH). If the bit is one, the result is negative, and if this bit is zero, the result is positive. Figure 26-14 shows the decoding of the differential input range. Table 82 shows the resulting output codes if the differential input channel pair (ADCn - ADCm) is selected with a reference voltage of VREF. ADC VIN ⋅ 1024 VREF = -------------------------- ADC VPOS VNEG ( ) – ⋅ ⋅ GAIN 512 VREF = ------------------------------------------------------------------------320 7593L–AVR–09/12 AT90USB64/128 Figure 26-14. Differential measurement range. 0 Output code 0x1FF 0x000 VREF Differential input voltage (volts) 0x3FF 0x200 - VREF321 7593L–AVR–09/12 AT90USB64/128 Example 1: – ADMUX = 0xED (ADC3 - ADC2, 10× gain, 2.56V reference, left adjusted result) – Voltage on ADC3 is 300mV, voltage on ADC2 is 500mV. – ADCR = 512 × 10 × (300 - 500) / 2560 = -400 = 0x270 – ADCL will thus read 0x00, and ADCH will read 0x9C. Writing zero to ADLAR right adjusts the result: ADCL = 0x70, ADCH = 0x02. Example 2: – ADMUX = 0xFB (ADC3 - ADC2, 1× gain, 2.56V reference, left adjusted result) – Voltage on ADC3 is 300mV, voltage on ADC2 is 500mV. – ADCR = 512 × 1 × (300 - 500) / 2560 = -41 = 0x029. – ADCL will thus read 0x40, and ADCH will read 0x0A. Writing zero to ADLAR right adjusts the result: ADCL = 0x00, ADCH = 0x29. 26.9 ADC register description 26.9.1 ADMUX – ADC Multiplexer Selection Register • Bit 7:6 – REFS1:0: Reference Selection bits These bits select the voltage reference for the ADC, as shown in Table 26-3 on page 322. If these bits are changed during a conversion, the change will not go in effect until this conversion Table 26-2. Correlation between input voltage and output codes. VADCn Read code Corresponding decimal value VADCm + VREF /GAIN 0x1FF 511 VADCm + 0.999 VREF /GAIN 0x1FF 511 VADCm + 0.998 VREF /GAIN 0x1FE 510 ... ... ... VADCm + 0.001 VREF /GAIN 0x001 1 VADCm 0x000 0 VADCm - 0.001 VREF /GAIN 0x3FF -1 ... ... ... VADCm - 0.999 VREF /GAIN 0x201 -511 VADCm - VREF /GAIN 0x200 -512 Bit 7 6 5 4 3 2 1 0 REFS1 REFS0 ADLAR MUX4 MUX3 MUX2 MUX1 MUX0 ADMUX Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0322 7593L–AVR–09/12 AT90USB64/128 is complete (ADIF in ADCSRA is set). The internal voltage reference options may not be used if an external reference voltage is being applied to the AREF pin. • Bit 5 – ADLAR: ADC Left Adjust Result The ADLAR bit affects the presentation of the ADC conversion result in the ADC Data Register. Write one to ADLAR to left adjust the result. Otherwise, the result is right adjusted. Changing the ADLAR bit will affect the ADC Data Register immediately, regardless of any ongoing conversions. For a complete description of this bit, see “ADCL and ADCH – The ADC data register” on page 324. • Bits 4:0 – MUX4:0: Analog Channel Selection bits The value of these bits selects which combination of analog inputs are connected to the ADC. These bits also select the gain for the differential channels. See Table 26-4 for details. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSRA is set). Table 26-3. Voltage reference selections for ADC. REFS1 REFS0 Voltage reference selection 0 0 AREF, internal VREF turned off 0 1 AVCC with external capacitor on AREF pin 1 0 Reserved 1 1 Internal 2.56V Voltage Reference with external capacitor on AREF pin Table 26-4. Input channel and gain selections. MUX4..0 Single ended input Positive differential input Negative differential input Gain 00000 ADC0 N/A 00001 ADC1 00010 ADC2 00011 ADC3 00100 ADC4 00101 ADC5 00110 ADC6 00111 ADC7323 7593L–AVR–09/12 AT90USB64/128 26.9.2 ADCSRA – ADC Control and Status Register A • Bit 7 – ADEN: ADC Enable Writing this bit to one enables the ADC. By writing it to zero, the ADC is turned off. Turning the ADC off while a conversion is in progress, will terminate this conversion. • Bit 6 – ADSC: ADC Start Conversion In Single Conversion mode, write this bit to one to start each conversion. In Free Running mode, write this bit to one to start the first conversion. The first conversion after ADSC has been written after the ADC has been enabled, or if ADSC is written at the same time as the ADC is enabled, 01000 N/A (ADC0 / ADC0 / 10x) 01001 ADC1 ADC0 10× 01010 (ADC0 / ADC0 / 200x) 01011 ADC1 ADC0 200× 01100 (Reserved - ADC2 / ADC2 / 10x) 01101 ADC3 ADC2 10× 01110 (ADC2 / ADC2 / 200x) 01111 ADC3 ADC2 200× 10000 ADC0 ADC1 1× 10001 (ADC1 / ADC1 / 1x) 10010 ADC2 ADC1 1× 10011 ADC3 ADC1 1× 10100 ADC4 ADC1 1× 10101 ADC5 ADC1 1× 10110 ADC6 ADC1 1× 10111 ADC7 ADC1 1× 11000 ADC0 ADC2 1× 11001 ADC1 ADC2 1× 11010 (ADC2 / ADC2 / 1x) 11011 ADC3 ADC2 1× 11100 ADC4 ADC2 1× 11101 ADC5 ADC2 1× 11110 1.1V (VBand Gap) N/A 11111 0V (GND) Table 26-4. Input channel and gain selections. (Continued) MUX4..0 Single ended input Positive differential input Negative differential input Gain Bit 7 6 5 4 3 2 1 0 ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 ADCSRA Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0324 7593L–AVR–09/12 AT90USB64/128 will take 25 ADC clock cycles instead of the normal 13. This first conversion performs initialization of the ADC. ADSC will read as one as long as a conversion is in progress. When the conversion is complete, it returns to zero. Writing zero to this bit has no effect. • Bit 5 – ADATE: ADC Auto Trigger Enable When this bit is written to one, Auto Triggering of the ADC is enabled. The ADC will start a conversion on a positive edge of the selected trigger signal. The trigger source is selected by setting the ADC Trigger Select bits, ADTS in ADCSRB. • Bit 4 – ADIF: ADC Interrupt Flag This bit is set when an ADC conversion completes and the Data Registers are updated. The ADC Conversion Complete Interrupt is executed if the ADIE bit and the I-bit in SREG are set. ADIF is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, ADIF is cleared by writing a logical one to the flag. Beware that if doing a Read-ModifyWrite on ADCSRA, a pending interrupt can be disabled. This also applies if the SBI and CBI instructions are used. • Bit 3 – ADIE: ADC Interrupt Enable When this bit is written to one and the I-bit in SREG is set, the ADC Conversion Complete Interrupt is activated. • Bits 2:0 – ADPS2:0: ADC Prescaler Select Bits These bits determine the division factor between the XTAL frequency and the input clock to the ADC. 26.9.3 ADCL and ADCH – The ADC data register 26.9.3.1 ADLAR = 0 Table 26-5. ADC prescaler selections. ADPS2 ADPS1 ADPS0 Division factor 000 2 001 2 010 4 011 8 1 0 0 16 1 0 1 32 1 1 0 64 1 1 1 128 Bit 15 14 13 12 11 10 9 8 – – – – – – ADC9 ADC8 ADCH ADC7 ADC6 ADC5 ADC4 ADC3 ADC2 ADC1 ADC0 ADCL Bit 7 6 5 4 3 2 1 0 Read/write R R R R R R R R RRRRRRRR Initial value 0 0 0 0 0 0 0 0 00000000325 7593L–AVR–09/12 AT90USB64/128 26.9.3.2 ADLAR = 1 When an ADC conversion is complete, the result is found in these two registers. If differential channels are used, the result is presented in two’s complement form. When ADCL is read, the ADC Data Register is not updated until ADCH is read. Consequently, if the result is left adjusted and no more than 8-bit precision (7 bit + sign bit for differential input channels) is required, it is sufficient to read ADCH. Otherwise, ADCL must be read first, then ADCH. The ADLAR bit in ADMUX, and the MUXn bits in ADMUX affect the way the result is read from the registers. If ADLAR is set, the result is left adjusted. If ADLAR is cleared (default), the result is right adjusted. • ADC9:0: ADC Conversion Result These bits represent the result from the conversion, as detailed in “ADC conversion result” on page 318. 26.9.4 ADCSRB – ADC Control and Status Register B • Bit 7 – ADHSM: ADC High Speed Mode Writing this bit to one enables the ADC High Speed mode. This mode enables higher conversion rate at the expense of higher power consumption. • Bit 2:0 – ADTS2:0: ADC Auto Trigger Source If ADATE in ADCSRA is written to one, the value of these bits selects which source will trigger an ADC conversion. If ADATE is cleared, the ADTS2:0 settings will have no effect. A conversion will be triggered by the rising edge of the selected interrupt flag. Note that switching from a trigger source that is cleared to a trigger source that is set, will generate a positive edge on the trigger signal. If ADEN in ADCSRA is set, this will start a conversion. Switching to Free Running mode (ADTS[2:0]=0) will not cause a trigger event, even if the ADC Interrupt Flag is set. Bit 15 14 13 12 11 10 9 8 ADC9 ADC8 ADC7 ADC6 ADC5 ADC4 ADC3 ADC2 ADCH ADC1 ADC0 – ––––– ADCL Bit 7 6 5 4 3 2 1 0 Read/write R R R R R R R R RRRRRRRR Initial value 0 0 0 0 0 0 0 0 00000000 Bit 7 6 5 4 3 2 1 0 ADHSM ACME – – – ADTS2 ADTS1 ADTS0 ADCSRB Read/write R/W R/W R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Table 26-6. ADC auto trigger source selections. ADTS2 ADTS1 ADTS0 Trigger source 0 0 0 Free running mode 0 0 1 Analog comparator 0 1 0 External interrupt request 0 0 1 1 Timer/Counter0 compare match326 7593L–AVR–09/12 AT90USB64/128 26.9.5 DIDR0 – Digital Input Disable Register 0 • Bit 7:0 – ADC7D..ADC0D: ADC7:0 Digital Input Disable When this bit is written logic one, the digital input buffer on the corresponding ADC pin is disabled. The corresponding PIN Register bit will always read as zero when this bit is set. When an analog signal is applied to the ADC7..0 pin and the digital input from this pin is not needed, this bit should be written logic one to reduce power consumption in the digital input buffer. 1 0 0 Timer/Counter0 overflow 1 0 1 Timer/Counter1 compare match B 1 1 0 Timer/Counter1 overflow 1 1 1 Timer/Counter1 capture event Table 26-6. ADC auto trigger source selections. (Continued) ADTS2 ADTS1 ADTS0 Trigger source Bit 7 6 5 4 3 2 1 0 ADC7D ADC6D ADC5D ADC4D ADC3D ADC2D ADC1D ADC0D DIDR0 Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0327 7593L–AVR–09/12 AT90USB64/128 27. JTAG interface and on-chip debug system 27.0.1 Features • JTAG (IEEE std. 1149.1 compliant) interface • Boundary-scan capabilities according to the IEEE std. 1149.1 (JTAG) standard • Debugger access to: – All internal peripheral units – Internal and external RAM – The internal register file – Program counter – EEPROM and flash memories • Extensive on-chip debug support for break conditions, including – AVR break instruction – Break on change of program memory flow – Single step break – Program memory break points on single address or address range – Data memory break points on single address or address range • Programming of flash, EEPROM, fuses, and lock bits through the JTAG interface • On-chip debugging supported by Atmel AVR Studio® 27.1 Overview The AVR IEEE std. 1149.1 compliant JTAG interface can be used for • Testing PCBs by using the JTAG Boundary-scan capability • Programming the non-volatile memories, Fuses and Lock bits • On-chip debugging A brief description is given in the following sections. Detailed descriptions for Programming via the JTAG interface, and using the Boundary-scan Chain can be found in the sections “Programming via the JTAG interface” on page 377 and “IEEE 1149.1 (JTAG) boundary-scan” on page 333, respectively. The On-chip Debug support is considered being private JTAG instructions, and distributed within Atmel and to selected third party vendors only. Figure 27-1 on page 328 shows a block diagram of the JTAG interface and the On-chip Debug system. The TAP Controller is a state machine controlled by the TCK and TMS signals. The TAP Controller selects either the JTAG Instruction Register or one of several Data Registers as the scan chain (Shift Register) between the TDI – input and TDO – output. The Instruction Register holds JTAG instructions controlling the behavior of a Data Register. The ID-Register, Bypass Register, and the Boundary-scan Chain are the Data Registers used for board-level testing. The JTAG Programming Interface (actually consisting of several physical and virtual Data Registers) is used for serial programming via the JTAG interface. The Internal Scan Chain and Break Point Scan Chain are used for On-chip debugging only. 27.2 TAP – Test Access Port The JTAG interface is accessed through four of the AVR’s pins. In JTAG terminology, these pins constitute the Test Access Port – TAP. These pins are: • TMS: Test mode select. This pin is used for navigating through the TAP-controller state machine • TCK: Test Clock. JTAG operation is synchronous to TCK328 7593L–AVR–09/12 AT90USB64/128 • TDI: Test Data In. Serial input data to be shifted in to the Instruction Register or Data Register (Scan Chains) • TDO: Test Data Out. Serial output data from Instruction Register or Data Register The IEEE std. 1149.1 also specifies an optional TAP signal; TRST – Test ReSeT – which is not provided. When the JTAGEN Fuse is unprogrammed, these four TAP pins are normal port pins, and the TAP controller is in reset. When programmed, the input TAP signals are internally pulled high and the JTAG is enabled for Boundary-scan and programming. The device is shipped with this fuse programmed. For the On-chip Debug system, in addition to the JTAG interface pins, the RESET pin is monitored by the debugger to be able to detect external reset sources. The debugger can also pull the RESET pin low to reset the whole system, assuming only open collectors on the reset line are used in the application. Figure 27-1. Block diagram. TAP CONTROLLER TDI TDO TCK TMS FLASH MEMORY AVR CPU DIGITAL PERIPHERAL UNITS JTAG / AVR CORE COMMUNICATION INTERFACE BREAKPOINT UNIT FLOW CONTROL UNIT OCD STATUS AND CONTROL INTERNAL SCAN CHAIN M U X INSTRUCTION REGISTER ID REGISTER BYPASS REGISTER JTAG PROGRAMMING INTERFACE PC Instruction Address Data BREAKPOINT SCAN CHAIN ADDRESS DECODER ANALOG PERIPHERIAL UNITS I/O PORT 0 I/O PORT n BOUNDARY SCAN CHAIN Analog inputs Control & clock lines DEVICE BOUNDARY329 7593L–AVR–09/12 AT90USB64/128 Figure 27-2. TAP controller state diagram. 27.3 TAP Controller The TAP Controller is a 16-state finite state machine that controls the operation of the Boundaryscan circuitry, JTAG programming circuitry, or On-chip Debug system. The state transitions depicted in Figure 27-2 depend on the signal present on TMS (shown adjacent to each state transition) at the time of the rising edge at TCK. The initial state after a Power-on Reset is TestLogic-Reset. As a definition in this document, the LSB is shifted in and out first for all Shift Registers. Assuming Run-Test/Idle is the present state, a typical scenario for using the JTAG interface is: • At the TMS input, apply the sequence 1, 1, 0, 0 at the rising edges of TCK to enter the Shift Instruction Register – Shift-IR state. While in this state, shift the four bits of the JTAG instructions into the JTAG Instruction Register from the TDI input at the rising edge of TCK. The TMS input must be held low during input of the three LSBs in order to remain in the ShiftIR state. The MSB of the instruction is shifted in when this state is left by setting TMS high. While the instruction is shifted in from the TDI pin, the captured IR-state 0x01 is shifted out on the TDO pin. The JTAG Instruction selects a particular Data Register as path between TDI and TDO and controls the circuitry surrounding the selected Data Register Test-logic-reset Run-test/idle Shift-DR Exit1-DR Pause-DR Exit2-DR Update-DR Select-IR scan Capture-IR Shift-IR Exit1-IR Pause-IR Exit2-IR Update-IR Select-DR scan Capture-DR 0 1 0 11 1 0 0 0 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 0 0 1 1330 7593L–AVR–09/12 AT90USB64/128 • Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. The instruction is latched onto the parallel output from the Shift Register path in the Update-IR state. The Exit-IR, Pause-IR, and Exit2-IR states are only used for navigating the state machine • At the TMS input, apply the sequence 1, 0, 0 at the rising edges of TCK to enter the Shift Data Register – Shift-DR state. While in this state, upload the selected Data Register (selected by the present JTAG instruction in the JTAG Instruction Register) from the TDI input at the rising edge of TCK. In order to remain in the Shift-DR state, the TMS input must be held low during input of all bits except the MSB. The MSB of the data is shifted in when this state is left by setting TMS high. While the Data Register is shifted in from the TDI pin, the parallel inputs to the Data Register captured in the Capture-DR state is shifted out on the TDO pin • Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. If the selected Data Register has a latched parallel-output, the latching takes place in the Update-DR state. The Exit-DR, Pause-DR, and Exit2-DR states are only used for navigating the state machine As shown in the state diagram, the Run-Test/Idle state need not be entered between selecting JTAG instruction and using Data Registers, and some JTAG instructions may select certain functions to be performed in the Run-Test/Idle, making it unsuitable as an Idle state. Note: Independent of the initial state of the TAP Controller, the Test-Logic-Reset state can always be entered by holding TMS high for five TCK clock periods. For detailed information on the JTAG specification, refer to the literature listed in “Bibliography” on page 332. 27.4 Using the Boundary-scan chain A complete description of the Boundary-scan capabilities are given in the section “IEEE 1149.1 (JTAG) boundary-scan” on page 333. 27.5 Using the on-chip debug system As shown in Figure 27-1 on page 328, the hardware support for on-chip debugging consists mainly of • A scan chain on the interface between the internal AVR CPU and the internal peripheral units • Break Point unit • Communication interface between the CPU and JTAG system All read or modify/write operations needed for implementing the Debugger are done by applying AVR instructions via the internal AVR CPU Scan Chain. The CPU sends the result to an I/O memory mapped location which is part of the communication interface between the CPU and the JTAG system. The Break Point Unit implements Break on Change of Program Flow, Single Step Break, two Program Memory Break Points, and two combined Break Points. Together, the four Break Points can be configured as either: • Four single program memory break points • Three single program memory break point + one single data memory break point • Two single program memory break points + two single data memory break points • Two single program memory break points + one program memory break point with mask (“range Break Point”)331 7593L–AVR–09/12 AT90USB64/128 • Two single program memory break points + one data memory break point with mask (“range Break Point”) A debugger, like the Atmel AVR Studio, may however use one or more of these resources for its internal purpose, leaving less flexibility to the end-user. A list of the On-chip Debug specific JTAG instructions is given in “On-chip debug specific JTAG instructions” on page 331. The JTAGEN Fuse must be programmed to enable the JTAG Test Access Port. In addition, the OCDEN Fuse must be programmed and no Lock bits must be set for the On-chip debug system to work. As a security feature, the On-chip debug system is disabled when either of the LB1 or LB2 Lock bits are set. Otherwise, the On-chip debug system would have provided a back-door into a secured device. The AVR Studio enables the user to fully control execution of programs on an AVR device with On-chip Debug capability, AVR In-Circuit Emulator, or the built-in AVR Instruction Set Simulator. AVR Studio supports source level execution of Assembly programs assembled with Atmel Corporation’s AVR Assembler and C programs compiled with third party vendors’ compilers. AVR Studio runs under Microsoft® Windows® 95/98/2000 and Microsoft Windows NT. For a full description of the Atmel AVR Studio, please refer to the AVR Studio User Guide. Only highlights are presented in this document. All necessary execution commands are available in AVR Studio, both on source level and on disassembly level. The user can execute the program, single step through the code either by tracing into or stepping over functions, step out of functions, place the cursor on a statement and execute until the statement is reached, stop the execution, and reset the execution target. In addition, the user can have an unlimited number of code Break Points (using the BREAK instruction) and up to two data memory Break Points, alternatively combined as a mask (range) Break Point. 27.6 On-chip debug specific JTAG instructions The On-chip debug support is considered being private JTAG instructions, and distributed within ATMEL and to selected third party vendors only. Instruction opcodes are listed for reference. 27.6.1 PRIVATE0; 0x8 Private JTAG instruction for accessing On-chip debug system. 27.6.2 PRIVATE1; 0x9 Private JTAG instruction for accessing On-chip debug system. 27.6.3 PRIVATE2; 0xA Private JTAG instruction for accessing On-chip debug system. 27.6.4 PRIVATE3; 0xB Private JTAG instruction for accessing On-chip debug system.332 7593L–AVR–09/12 AT90USB64/128 27.7 On-chip Debug related Register in I/O memory 27.7.1 OCDR – On-chip Debug Register The OCDR Register provides a communication channel from the running program in the microcontroller to the debugger. The CPU can transfer a byte to the debugger by writing to this location. At the same time, an internal flag; I/O Debug Register Dirty – IDRD – is set to indicate to the debugger that the register has been written. When the CPU reads the OCDR Register the seven LSB will be from the OCDR Register, while the MSB is the IDRD bit. The debugger clears the IDRD bit when it has read the information. In some AVR devices, this register is shared with a standard I/O location. In this case, the OCDR Register can only be accessed if the OCDEN Fuse is programmed, and the debugger enables access to the OCDR Register. In all other cases, the standard I/O location is accessed. Refer to the debugger documentation for further information on how to use this register. 27.8 Using the JTAG programming capabilities Programming of AVR parts via JTAG is performed via the 4-pin JTAG port, TCK, TMS, TDI, and TDO. These are the only pins that need to be controlled/observed to perform JTAG programming (in addition to power pins). It is not required to apply 12V externally. The JTAGEN Fuse must be programmed and the JTD bit in the MCUCR Register must be cleared to enable the JTAG Test Access Port. The JTAG programming capability supports: • Flash programming and verifying • EEPROM programming and verifying • Fuse programming and verifying • Lock bit programming and verifying The Lock bit security is exactly as in parallel programming mode. If the Lock bits LB1 or LB2 are programmed, the OCDEN Fuse cannot be programmed unless first doing a chip erase. This is a security feature that ensures no back-door exists for reading out the content of a secured device. The details on programming through the JTAG interface and programming specific JTAG instructions are given in the section “Programming via the JTAG interface” on page 377. 27.9 Bibliography For more information about general Boundary-scan, the following literature can be consulted: • IEEE: IEEE Std. 1149.1-1990. IEEE Standard Test Access Port and Boundary-scan Architecture, IEEE, 1993. • Colin Maunder: The Board Designers Guide to Testable Logic Circuits, Addison-Wesley, 1992. Bit 7 6 5 4 3 2 1 0 MSB/IDRD LSB OCDR Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0333 7593L–AVR–09/12 AT90USB64/128 28. IEEE 1149.1 (JTAG) boundary-scan 28.1 Features • JTAG (IEEE std. 1149.1 compliant) interface • Boundary-scan capabilities according to the JTAG standard • Full scan of all port functions as well as analog circuitry having off-chip connections • Supports the optional IDCODE instruction • Additional public AVR_RESET instruction to reset the AVR 28.2 System overview The Boundary-scan chain has the capability of driving and observing the logic levels on the digital I/O pins, as well as the boundary between digital and analog logic for analog circuitry having off-chip connections. At system level, all ICs having JTAG capabilities are connected serially by the TDI/TDO signals to form a long Shift Register. An external controller sets up the devices to drive values at their output pins, and observe the input values received from other devices. The controller compares the received data with the expected result. In this way, Boundary-scan provides a mechanism for testing interconnections and integrity of components on Printed Circuits Boards by using the four TAP signals only. The four IEEE 1149.1 defined mandatory JTAG instructions IDCODE, BYPASS, SAMPLE/PRELOAD, and EXTEST, as well as the AVR specific public JTAG instruction AVR_RESET can be used for testing the Printed Circuit Board. Initial scanning of the Data Register path will show the ID-Code of the device, since IDCODE is the default JTAG instruction. It may be desirable to have the AVR device in reset during test mode. If not reset, inputs to the device may be determined by the scan operations, and the internal software may be in an undetermined state when exiting the test mode. Entering reset, the outputs of any port pin will instantly enter the high impedance state, making the HIGHZ instruction redundant. If needed, the BYPASS instruction can be issued to make the shortest possible scan chain through the device. The device can be set in the reset state either by pulling the external RESET pin low, or issuing the AVR_RESET instruction with appropriate setting of the Reset Data Register. The EXTEST instruction is used for sampling external pins and loading output pins with data. The data from the output latch will be driven out on the pins as soon as the EXTEST instruction is loaded into the JTAG IR-Register. Therefore, the SAMPLE/PRELOAD should also be used for setting initial values to the scan ring, to avoid damaging the board when issuing the EXTEST instruction for the first time. SAMPLE/PRELOAD can also be used for taking a snapshot of the external pins during normal operation of the part. The JTAGEN Fuse must be programmed and the JTD bit in the I/O Register MCUCR must be cleared to enable the JTAG Test Access Port. When using the JTAG interface for Boundary-scan, using a JTAG TCK clock frequency higher than the internal chip frequency is possible. The chip clock is not required to run. 28.3 Data registers The Data Registers relevant for Boundary-scan operations are: • Bypass Register • Device Identification Register • Reset Register • Boundary-scan Chain334 7593L–AVR–09/12 AT90USB64/128 28.3.1 Bypass register The Bypass register consists of a single Shift register stage. When the Bypass register is selected as path between TDI and TDO, the register is reset to 0 when leaving the Capture-DR controller state. The Bypass register can be used to shorten the scan chain on a system when the other devices are to be tested. 28.3.2 Device Identification register Figure 28-1 shows the structure of the Device Identification register. Figure 28-1. The Format of the Device Identification register. 28.3.2.1 Version Version is a 4-bit number identifying the revision of the component. The JTAG version number follows the revision of the device. Revision A is 0x0, revision B is 0x1 and so on. 28.3.2.2 Part number The part number is a 16-bit code identifying the component. The JTAG Part Number for Atmel AT90USB64/128 is listed in Table 28-1. 28.3.2.3 Manufacturer ID The Manufacturer ID is a 11-bit code identifying the manufacturer. The JTAG manufacturer ID for ATMEL is listed in Table 28-2. 28.3.3 Reset register The Reset Register is a test Data Register used to reset the part. Since the AVR tri-states Port Pins when reset, the Reset Register can also replace the function of the un-implemented optional JTAG instruction HIGHZ. A high value in the Reset Register corresponds to pulling the external Reset low. The part is reset as long as there is a high value present in the Reset Register. Depending on the fuse settings for the clock options, the part will remain reset for a reset time-out period (refer to “Clock sources” on page 41) after releasing the Reset Register. The output from this Data Register is not latched, so the reset will take place immediately, as shown in Figure 28-2 on page 335. MSB LSB Bit 31 28 27 12 11 1 0 Device ID Version Part number Manufacturer ID 1 4 bits 16 bits 11 bits 1-bit Table 28-1. AVR JTAG part number. Part number JTAG part number (hex) AVR USB 0x9782 Table 28-2. Manufacturer ID. Manufacturer JTAG manufacturer ID (hex) ATMEL 0x01F335 7593L–AVR–09/12 AT90USB64/128 Figure 28-2. Reset register. 28.3.4 Boundary-scan Chain The Boundary-scan Chain has the capability of driving and observing the logic levels on the digital I/O pins, as well as the boundary between digital and analog logic for analog circuitry having off-chip connections. See “Boundary-scan chain” on page 337 for a complete description. 28.4 Boundary-scan specific JTAG instructions The Instruction Register is 4-bit wide, supporting up to 16 instructions. Listed below are the JTAG instructions useful for Boundary-scan operation. Note that the optional HIGHZ instruction is not implemented, but all outputs with tri-state capability can be set in high-impedant state by using the AVR_RESET instruction, since the initial state for all port pins is tri-state. As a definition in this datasheet, the LSB is shifted in and out first for all Shift Registers. The OPCODE for each instruction is shown behind the instruction name in hex format. The text describes which Data Register is selected as path between TDI and TDO for each instruction. 28.4.1 EXTEST; 0x0 Mandatory JTAG instruction for selecting the Boundary-scan Chain as Data Register for testing circuitry external to the AVR package. For port-pins, Pull-up Disable, Output Control, Output Data, and Input Data are all accessible in the scan chain. For Analog circuits having off-chip connections, the interface between the analog and the digital logic is in the scan chain. The contents of the latched outputs of the Boundary-scan chain is driven out as soon as the JTAG IRRegister is loaded with the EXTEST instruction. The active states are: • Capture-DR: Data on the external pins are sampled into the Boundary-scan Chain • Shift-DR: The Internal Scan Chain is shifted by the TCK input • Update-DR: Data from the scan chain is applied to output pins 28.4.2 IDCODE; 0x1 Optional JTAG instruction selecting the 32-bit ID-Register as Data Register. The ID-Register consists of a version number, a device number and the manufacturer code chosen by JEDEC. This is the default instruction after power-up. D Q From TDI ClockDR · AVR_RESET To TDO From other internal and external reset sources Internal reset336 7593L–AVR–09/12 AT90USB64/128 The active states are: • Capture-DR: Data in the IDCODE Register is sampled into the Boundary-scan Chain • Shift-DR: The IDCODE scan chain is shifted by the TCK input 28.4.3 SAMPLE_PRELOAD; 0x2 Mandatory JTAG instruction for pre-loading the output latches and taking a snap-shot of the input/output pins without affecting the system operation. However, the output latches are not connected to the pins. The Boundary-scan Chain is selected as Data Register. The active states are: • Capture-DR: Data on the external pins are sampled into the Boundary-scan Chain • Shift-DR: The Boundary-scan Chain is shifted by the TCK input • Update-DR: Data from the Boundary-scan chain is applied to the output latches. However, the output latches are not connected to the pins 28.4.4 AVR_RESET; 0xC The AVR specific public JTAG instruction for forcing the AVR device into the Reset mode or releasing the JTAG reset source. The TAP controller is not reset by this instruction. The one bit Reset Register is selected as Data Register. Note that the reset will be active as long as there is a logic “one” in the Reset Chain. The output from this chain is not latched. The active states are: • Shift-DR: The Reset Register is shifted by the TCK input 28.4.5 BYPASS; 0xF Mandatory JTAG instruction selecting the Bypass Register for Data Register. The active states are: • Capture-DR: Loads a logic “0” into the Bypass Register • Shift-DR: The Bypass Register cell between TDI and TDO is shifted 28.5 Boundary-scan Related Register in I/O memory 28.5.1 MCUCR – MCU Control Register The MCU Control Register contains control bits for general MCU functions. • Bits 7 – JTD: JTAG Interface Disable When this bit is zero, the JTAG interface is enabled if the JTAGEN Fuse is programmed. If this bit is one, the JTAG interface is disabled. In order to avoid unintentional disabling or enabling of the JTAG interface, a timed sequence must be followed when changing this bit: The application software must write this bit to the desired value twice within four cycles to change its value. Note that this bit must not be altered when using the On-chip Debug system. Bit 7 6 5 4 3 2 1 0 JTD – – PUD – – IVSEL IVCE MCUCR Read/write R/W R R R/W R R R/W R/W Initial value 0 0 0 0 0 0 0 0337 7593L–AVR–09/12 AT90USB64/128 28.5.2 MCUSR – MCU Status Register The MCU Status Register provides information on which reset source caused an MCU reset. • Bit 4 – JTRF: JTAG Reset Flag This bit is set if a reset is being caused by a logic one in the JTAG Reset Register selected by the JTAG instruction AVR_RESET. This bit is reset by a Power-on Reset, or by writing a logic zero to the flag. 28.6 Boundary-scan chain The Boundary-scan chain has the capability of driving and observing the logic levels on the digital I/O pins, as well as the boundary between digital and analog logic for analog circuitry having off-chip connection. 28.6.1 Scanning the digital port pins Figure 28-3 on page 338 shows the Boundary-scan Cell for a bi-directional port pin. The pull-up function is disabled during Boundary-scan when the JTAG IC contains EXTEST or SAMPLE_PRELOAD. The cell consists of a bi-directional pin cell that combines the three signals Output Control - OCxn, Output Data - ODxn, and Input Data - IDxn, into only a two-stage Shift Register. The port and pin indexes are not used in the following description The Boundary-scan logic is not included in the figures in the datasheet. Figure 28-4 on page 339 shows a simple digital port pin as described in the section “I/O-ports” on page 71. The Boundaryscan details from Figure 28-3 on page 338 replaces the dashed box in Figure 28-4 on page 339. When no alternate port function is present, the Input Data - ID - corresponds to the PINxn Register value (but ID has no synchronizer), Output Data corresponds to the PORT Register, Output Control corresponds to the Data Direction - DD Register, and the Pull-up Enable - PUExn - corresponds to logic expression PUD · DDxn · PORTxn. Digital alternate port functions are connected outside the dotted box in Figure 28-4 on page 339 to make the scan chain read the actual pin value. For analog function, there is a direct connection from the external pin to the analog circuit. There is no scan chain on the interface between the digital and the analog circuitry, but some digital control signal to analog circuitry are turned off to avoid driving contention on the pads. When JTAG IR contains EXTEST or SAMPLE_PRELOAD the clock is not sent out on the port pins even if the CKOUT fuse is programmed. Even though the clock is output when the JTAG IR contains SAMPLE_PRELOAD, the clock is not sampled by the boundary scan. Bit 7 6 5 4 3 2 1 0 – – – JTRF WDRF BORF EXTRF PORF MCUSR Read/write R R R R/W R/W R/W R/W R/W Initial value 0 0 0 See bit description338 7593L–AVR–09/12 AT90USB64/128 Figure 28-3. Boundary-scan cell for bi-directional port pin with pull-up function. D Q D Q G 0 1 0 1 D Q D Q G 0 1 0 1 0 1 Port Pin (PXn) ShiftDR To next cell EXTEST Vcc Output control (OC) Output data (OD) Input data (ID) From last cell ClockDR UpdateDR FF1 LD1 FF0 LD0 0 1 Pull-up enable (PUE)339 7593L–AVR–09/12 AT90USB64/128 Figure 28-4. General port pin schematic diagram. 28.6.2 Scanning the RESET pin The RESET pin accepts 5V active low logic for standard reset operation, and 12V active high logic for High Voltage Parallel programming. An observe-only cell as shown in Figure 28-5 is inserted for the 5V reset signal. Figure 28-5. Observe-only cell. CLK RPx RRx WRx RDx WDx PUD SYNCHRONIZER WDx: WRITE DDRx WRx: WRITE PORTx RRx: READ PORTx REGISTER RPx: READ PORTx PIN PUD: PULLUP DISABLE CLK : I/O CLOCK RDx: READ DDRx D L Q Q RESET RESET Q D Q Q Q D CLR PORTxn Q Q D CLR DDxn PINxn DATA BUS SLEEP SLEEP: SLEEP CONTROL Pxn I/O I/O See Boundary-scan description for details! PUExn OCxn ODxn IDxn PUExn: PULLUP ENABLE for pin Pxn OCxn: OUTPUT CONTROL for pin Pxn ODxn: OUTPUT DATA to pin Pxn IDxn: INPUT DATA from pin Pxn 0 1 D Q From previous cell ClockDR ShiftDR To next cell From system pin To system logic FF1340 7593L–AVR–09/12 AT90USB64/128 28.7 Atmel AT90USB64/128 Boundary-scan order Table 28-3 shows the Scan order between TDI and TDO when the Boundary-scan chain is selected as data path. Bit 0 is the LSB; the first bit scanned in, and the first bit scanned out. The scan order follows the pin-out order as far as possible. Therefore, the bits of Port A and Port Fis scanned in the opposite bit order of the other ports. Exceptions from the rules are the Scan chains for the analog circuits, which constitute the most significant bits of the scan chain regardless of which physical pin they are connected to. In Figure 28-3 on page 338, PXn. Data corresponds to FF0, PXn. Control corresponds to FF1, PXn. Bit 4, 5, 6 and 7 of Port F is not in the scan chain, since these pins constitute the TAP pins when the JTAG is enabled. The USB pads are not included in the boundary-scan. Table 28-3. AT90USB64/128 Boundary-scan order. Bit number Signal name Module 88 PE6.Data Port E 87 PE6.Control 86 PE7.Data 85 PE7.Control 84 PE3.Data 83 PE3.Control 82 PB0.Data Port B 81 PB0.Control 80 PB1.Data 79 PB1.Control 78 PB2.Data 77 PB2.Control 76 PB3.Data 75 PB3.Control 74 PB4.Data 73 PB4.Control 72 PB5.Data 71 PB5.Control 70 PB6.Data 69 PB6.Control 68 PB7.Data 67 PB7.Control 66 PE4.Data PORTE 65 PE4.Control 64 PE5.Data 63 PE5.Control 62 RSTT Reset Logic (observe only)341 7593L–AVR–09/12 AT90USB64/128 61 PD0.Data Port D 60 PD0.Control 59 PD1.Data 58 PD1.Control 57 PD2.Data 56 PD2.Control 55 PD3.Data 54 PD3.Control 53 PD4.Data 52 PD4.Control 51 PD5.Data 50 PD5.Control 49 PD6.Data 48 PD6.Control 47 PD7.Data 46 PD7.Control 45 PE0.Data Port E 44 PE0.Control 43 PE1.Data 42 PE1.Control 41 PC0.Data Port C 40 PC0.Control 39 PC1.Data 38 PC1.Control 37 PC2.Data 36 PC2.Control 35 PC3.Data 34 PC3.Control 33 PC4.Data 32 PC4.Control 31 PC5.Data 30 PC5.Control 29 PC6.Data 28 PC6.Control 27 PC7.Data 26 PC7.Control Table 28-3. AT90USB64/128 Boundary-scan order. (Continued) Bit number Signal name Module342 7593L–AVR–09/12 AT90USB64/128 28.8 Boundary-scan description language files Boundary-scan Description Language (BSDL) files describe Boundary-scan capable devices in a standard format used by automated test-generation software. The order and function of bits in the Boundary-scan Data Register are included in this description. BSDL files are available for Atmel AT90USB64/128. 25 PE2.Data Port E 24 PE2.Control 23 PA7.Data Port A 22 PA7.Control 21 PA6.Data 20 PA6.Control 19 PA5.Data 18 PA5.Control 17 PA4.Data 16 PA4.Control 15 PA3.Data 14 PA3.Control 13 PA2.Data 12 PA2.Control 11 PA1.Data 10 PA1.Control 9 PA0.Data 8 PA0.Control 7 PF3.Data Port F 6 PF3.Control 5 PF2.Data 4 PF2.Control 3 PF1.Data 2 PF1.Control 1 PF0.Data 0 PF0.Control Table 28-3. AT90USB64/128 Boundary-scan order. (Continued) Bit number Signal name Module343 7593L–AVR–09/12 AT90USB64/128 29. Boot Loader support – read-while-write self-programming The Boot Loader Support provides a real Read-While-Write Self-Programming mechanism for downloading and uploading program code by the MCU itself. This feature allows flexible application software updates controlled by the MCU using a Flash-resident Boot Loader program. The Boot Loader program can use any available data interface and associated protocol to read code and write (program) that code into the Flash memory, or read the code from the program memory. The program code within the Boot Loader section has the capability to write into the entire Flash, including the Boot Loader memory. The Boot Loader can thus even modify itself, and it can also erase itself from the code if the feature is not needed anymore. The size of the Boot Loader memory is configurable with fuses and the Boot Loader has two separate sets of Boot Lock bits which can be set independently. This gives the user a unique flexibility to select different levels of protection. General information on SPM and ELPM is provided in See “AVR CPU core” on page 11. 29.1 Boot Loader features • Read-while-write self-programming • Flexible boot memory size • High security (separate boot lock bits for a flexible protection) • Separate fuse to select reset vector • Optimized page (1) size • Code efficient algorithm • Efficient read-modify-write support Note: 1. A page is a section in the Flash consisting of several bytes (see Table 30-11 on page 364) used during programming. The page organization does not affect normal operation. 29.2 Application and Boot Loader flash sections The Flash memory is organized in two main sections, the Application section and the Boot Loader section (see Figure 29-2 on page 346). The size of the different sections is configured by the BOOTSZ Fuses as shown in Table 29-8 on page 357 and Figure 29-2 on page 346. These two sections can have different level of protection since they have different sets of Lock bits. 29.2.1 Application section The Application section is the section of the Flash that is used for storing the application code. The protection level for the Application section can be selected by the application Boot Lock bits (Boot Lock bits 0), see Table 29-2 on page 347. The Application section can never store any Boot Loader code since the SPM instruction is disabled when executed from the Application section. 29.2.2 BLS – Boot Loader section While the Application section is used for storing the application code, the The Boot Loader software must be located in the BLS since the SPM instruction can initiate a programming when executing from the BLS only. The SPM instruction can access the entire Flash, including the BLS itself. The protection level for the Boot Loader section can be selected by the Boot Loader Lock bits (Boot Lock bits 1), see Table 29-3 on page 347. 29.3 Read-while-write and no read-while-write flash sections Whether the CPU supports Read-While-Write or if the CPU is halted during a Boot Loader software update is dependent on which address that is being programmed. In addition to the two344 7593L–AVR–09/12 AT90USB64/128 sections that are configurable by the BOOTSZ Fuses as described above, the Flash is also divided into two fixed sections, the Read-While-Write (RWW) section and the No Read-WhileWrite (NRWW) section. The limit between the RWW- and NRWW sections is given in Table 29- 1 and Figure 29-1 on page 345. The main difference between the two sections is: • When erasing or writing a page located inside the RWW section, the NRWW section can be read during the operation • When erasing or writing a page located inside the NRWW section, the CPU is halted during the entire operation Note that the user software can never read any code that is located inside the RWW section during a Boot Loader software operation. The syntax “Read-While-Write section” refers to which section that is being programmed (erased or written), not which section that actually is being read during a Boot Loader software update. 29.3.1 RWW – Read-While-Write section If a Boot Loader software update is programming a page inside the RWW section, it is possible to read code from the Flash, but only code that is located in the NRWW section. During an ongoing programming, the software must ensure that the RWW section never is being read. If the user software is trying to read code that is located inside the RWW section (i.e., by load program memory, call, or jump instructions or an interrupt) during programming, the software might end up in an unknown state. To avoid this, the interrupts should either be disabled or moved to the Boot Loader section. The Boot Loader section is always located in the NRWW section. The RWW Section Busy bit (RWWSB) in the Store Program Memory Control and Status Register (SPMCSR) will be read as logical one as long as the RWW section is blocked for reading. After a programming is completed, the RWWSB must be cleared by software before reading code located in the RWW section. See “SPMCSR – Store Program Memory Control and Status Register” on page 349. for details on how to clear RWWSB. 29.3.2 NRWW – No Read-While-Write section The code located in the NRWW section can be read when the Boot Loader software is updating a page in the RWW section. When the Boot Loader code updates the NRWW section, the CPU is halted during the entire Page Erase or Page Write operation. Table 29-1. Read-While-Write features. Which section does the Zpointer address during the programming? Which section can be read during programming? Is the CPU halted? Read-While-Write supported? RWW section NRWW section No Yes NRWW section None Yes No345 7593L–AVR–09/12 AT90USB64/128 Figure 29-1. Read-While-Write vs. no Read-While-Write. Read-While-Write (RWW) section No Read-While-Write (NRWW) section Z-pointer Addresses RWW section Z-pointer addresses NRWW section CPU is halted during the operation Code located in NRWW section. Can be read during the operation346 7593L–AVR–09/12 AT90USB64/128 Figure 29-2. Memory sections. Note: 1. The parameters in the figure above are given in Table 29-8 on page 357. 29.4 Boot Loader lock bits If no Boot Loader capability is needed, the entire Flash is available for application code. The Boot Loader has two separate sets of Boot Lock bits which can be set independently. This gives the user a unique flexibility to select different levels of protection. The user can select: • To protect the entire Flash from a software update by the MCU • To protect only the Boot Loader Flash section from a software update by the MCU • To protect only the Application Flash section from a software update by the MCU • Allow software update in the entire Flash See Table 29-2 on page 347 and Table 29-3 on page 347 for further details. The Boot Lock bits can be set by software and in Serial or in Parallel Programming mode. They can only be cleared by a Chip Erase command only. The general Write Lock (Lock Bit mode 2) does not control the programming of the Flash memory by SPM instruction. Similarly, the general Read/Write Lock (Lock Bit mode 1) does not control reading nor writing by (E)LPM/SPM, if it is attempted. 0x0000 Flashend Program memory BOOTSZ = '11' Application flash section Boot loader flash section Flashend Program memory BOOTSZ = '10' 0x0000 Program memory BOOTSZ = '01' Program memory BOOTSZ = '00' Application flash section Boot loader flash section 0x0000 Flashend Application flash section Flashend End RWW Start NRWW Application flash section Boot loader flash section Boot loader flash section End RWW Start NRWW End RWW Start NRWW 0x0000 End RWW, end application Start NRWW, start boot loader Application flash section Application flash section Application flash section Read-While-Write section No Read-While-Write section Read-While-Write section No Read-While-Write section Read-While-Write section No Read-While-Write section Read-While-Write section No Read-While-Write section End application Start boot loader End application Start boot loader End application Start boot loader347 7593L–AVR–09/12 AT90USB64/128 Note: 1. “1” means unprogrammed, “0” means programmed. Note: 1. “1” means unprogrammed, “0” means programmed. 29.5 Entering the Boot Loader program The boot loader can be executed with three different conditions: 29.5.1 Regular application conditions. A jump or call from the application program. This may be initiated by a trigger such as a command received via USART, SPI or USB. 29.5.2 Boot Reset fuse The Boot Reset Fuse (BOOTRST) can be programmed so that the Reset Vector is pointing to the Boot Flash start address after a reset. In this case, the Boot Loader is started after a reset. After the application code is loaded, the program can start executing the application code. Note that the fuses cannot be changed by the MCU itself. This means that once the Boot Reset Fuse is programmed, the Reset Vector will always point to the Boot Loader Reset and the fuse can only be changed through the serial or parallel programming interface. Table 29-2. Boot Lock Bit0 protection modes (application section) (1). BLB0 Mode BLB02 BLB01 Protection 1 11 No restrictions for SPM or (E)LPM accessing the Application section. 2 1 0 SPM is not allowed to write to the Application section. 3 00 SPM is not allowed to write to the Application section, and (E)LPM executing from the Boot Loader section is not allowed to read from the Application section. If Interrupt Vectors are placed in the Boot Loader section, interrupts are disabled while executing from the Application section. 4 01 (E)LPM executing from the Boot Loader section is not allowed to read from the Application section. If Interrupt Vectors are placed in the Boot Loader section, interrupts are disabled while executing from the Application section. Table 29-3. Boot Lock Bit1 protection modes (boot loader section) (1). BLB1 Mode BLB12 BLB11 Protection 1 11 No restrictions for SPM or (E)LPM accessing the Boot Loader section. 2 1 0 SPM is not allowed to write to the Boot Loader section. 3 00 SPM is not allowed to write to the Boot Loader section, and (E)LPM executing from the Application section is not allowed to read from the Boot Loader section. If Interrupt Vectors are placed in the Application section, interrupts are disabled while executing from the Boot Loader section. 4 01 (E)LPM executing from the Application section is not allowed to read from the Boot Loader section. If Interrupt Vectors are placed in the Application section, interrupts are disabled while executing from the Boot Loader section.348 7593L–AVR–09/12 AT90USB64/128 Note: 1. “1” means unprogrammed, “0” means programmed. 29.5.3 External hardware conditions The Hardware Boot Enable Fuse (HWBE) can be programmed (see Table 29-5) so that upon special hardware conditions under reset, the boot loader execution is forced after reset. Note: 1. “1” means unprogrammed, “0” means programmed. When the HWBE fuse is enable the ALE/HWB pin is configured as input during reset and sampled during reset rising edge. When ALE/HWB pin is ‘0’ during reset rising edge, the reset vector will be set as the Boot Loader Reset address and the Boot Loader will be executed (see Figure 29-3). Figure 29-3. Boot process description. Table 29-4. Boot reset fuse (1). BOOTRST Reset address 1 Reset Vector = Application reset (address 0x0000) 0 Reset Vector = Boot loader reset (see Table 29-8 on page 357) Table 29-5. Hardware boot enable fuse (1). HWBE Reset address 1 ALE/HWB pin can not be used to force boot loader execution after reset 0 ALE/HWB pin is used during reset to force boot loader execution after reset HWBE BOOTRST ? Ext. hardware conditions ? Reset vector = Application reset Reset vector = Boot loader reset ? RESET ALE/HWB t SHRH t HHRH349 7593L–AVR–09/12 AT90USB64/128 29.5.4 SPMCSR – Store Program Memory Control and Status Register The Store Program Memory Control and Status Register contains the control bits needed to control the Boot Loader operations. • Bit 7 – SPMIE: SPM Interrupt Enable When the SPMIE bit is written to one, and the I-bit in the Status Register is set (one), the SPM ready interrupt will be enabled. The SPM ready Interrupt will be executed as long as the SPMEN bit in the SPMCSR Register is cleared. • Bit 6 – RWWSB: Read-While-Write Section Busy When a Self-Programming (Page Erase or Page Write) operation to the RWW section is initiated, the RWWSB will be set (one) by hardware. When the RWWSB bit is set, the RWW section cannot be accessed. The RWWSB bit will be cleared if the RWWSRE bit is written to one after a Self-Programming operation is completed. Alternatively the RWWSB bit will automatically be cleared if a page load operation is initiated. • Bit 5 – SIGRD: Signature Row Read If this bit is written to one at the same time as SPMEN, the next LPM instruction within three clock cycles will read a byte from the signature row into the destination register. see “Reading the Signature Row from software” on page 354 for details. An SPM instruction within four cycles after SIGRD and SPMEN are set will have no effect. This operation is reserved for future use and should not be used. • Bit 4 – RWWSRE: Read-While-Write Section Read Enable When programming (Page Erase or Page Write) to the RWW section, the RWW section is blocked for reading (the RWWSB will be set by hardware). To re-enable the RWW section, the user software must wait until the programming is completed (SPMEN will be cleared). Then, if the RWWSRE bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles re-enables the RWW section. The RWW section cannot be re-enabled while the Flash is busy with a Page Erase or a Page Write (SPMEN is set). If the RWWSRE bit is written while the Flash is being loaded, the Flash load operation will abort and the data loaded will be lost. • Bit 3 – BLBSET: Boot Lock Bit Set If this bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles sets Boot Lock bits, according to the data in R0. The data in R1 and the address in the Zpointer are ignored. The BLBSET bit will automatically be cleared upon completion of the Lock bit set, or if no SPM instruction is executed within four clock cycles. An (E)LPM instruction within three cycles after BLBSET and SPMEN are set in the SPMCSR Register, will read either the Lock bits or the Fuse bits (depending on Z0 in the Z-pointer) into the destination register. See “Reading the Fuse and Lock bits from software” on page 353 for details. Bit 7 6 5 4 3 2 1 0 SPMIE RWWSB SIGRD RWWSRE BLBSET PGWRT PGERS SPMEN SPMCSR Read/write R/W R R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0350 7593L–AVR–09/12 AT90USB64/128 • Bit 2 – PGWRT: Page Write If this bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles executes Page Write, with the data stored in the temporary buffer. The page address is taken from the high part of the Z-pointer. The data in R1 and R0 are ignored. The PGWRT bit will auto-clear upon completion of a Page Write, or if no SPM instruction is executed within four clock cycles. The CPU is halted during the entire Page Write operation if the NRWW section is addressed. • Bit 1 – PGERS: Page Erase If this bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles executes Page Erase. The page address is taken from the high part of the Z-pointer. The data in R1 and R0 are ignored. The PGERS bit will auto-clear upon completion of a Page Erase, or if no SPM instruction is executed within four clock cycles. The CPU is halted during the entire Page Write operation if the NRWW section is addressed. • Bit 0 – SPMEN: Store Program Memory Enable This bit enables the SPM instruction for the next four clock cycles. If written to one together with either RWWSRE, BLBSET, PGWRT’ or PGERS, the following SPM instruction will have a special meaning, see description above. If only SPMEN is written, the following SPM instruction will store the value in R1:R0 in the temporary page buffer addressed by the Z-pointer. The LSB of the Z-pointer is ignored. The SPMEN bit will auto-clear upon completion of an SPM instruction, or if no SPM instruction is executed within four clock cycles. During Page Erase and Page Write, the SPMEN bit remains high until the operation is completed. Writing any other combination than “10001”, “01001”, “00101”, “00011” or “00001” in the lower five bits will have no effect. Note: Only one SPM instruction should be active at any time. 29.6 Addressing the flash during self-programming The Z-pointer is used to address the SPM commands. The Z pointer consists of the Z-registers ZL and ZH in the register file, and RAMPZ in the I/O space. The number of bits actually used is implementation dependent. Note that the RAMPZ register is only implemented when the program space is larger than 64kBytes. Since the Flash is organized in pages (see Table 30-11 on page 364), the Program Counter can be treated as having two different sections. One section, consisting of the least significant bits, is addressing the words within a page, while the most significant bits are addressing the pages. This is shown in Figure 29-4 on page 351. Note that the Page Erase and Page Write operations are addressed independently. Therefore it is of major importance that the Boot Loader software addresses the same page in both the Page Erase and Page Write operation. Once a programming operation is initiated, the address is latched and the Z-pointer can be used for other operations. The (E)LPM instruction use the Z-pointer to store the address. Since this instruction addresses the Flash byte-by-byte, also bit Z0 of the Z-pointer is used. Bit 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 RAMPZ RAMPZ7 RAMPZ6 RAMPZ5 RAMPZ4 RAMPZ3 RAMPZ2 RAMPZ1 RAMPZ0 ZH (R31) Z15 Z14 Z13 Z12 Z11 Z10 Z9 Z8 ZL (R30) Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z0 76543210351 7593L–AVR–09/12 AT90USB64/128 Figure 29-4. Addressing the flash during SPM (1). Note: 1. The different variables used in Figure 29-4 are listed in Table 29-10 on page 358. 29.7 Self-programming the flash The program memory is updated in a page by page fashion. Before programming a page with the data stored in the temporary page buffer, the page must be erased. The temporary page buffer is filled one word at a time using SPM and the buffer can be filled either before the Page Erase command or between a Page Erase and a Page Write operation: Alternative 1, fill the buffer before a Page Erase • Fill temporary page buffer • Perform a Page Erase • Perform a Page Write Alternative 2, fill the buffer after Page Erase • Perform a Page Erase • Fill temporary page buffer • Perform a Page Write If only a part of the page needs to be changed, the rest of the page must be stored (for example in the temporary page buffer) before the erase, and then be rewritten. When using alternative 1, the Boot Loader provides an effective Read-Modify-Write feature which allows the user software to first read the page, do the necessary changes, and then write back the modified data. If alternative 2 is used, it is not possible to read the old data while loading since the page is already erased. The temporary page buffer can be accessed in a random sequence. It is essential that the page address used in both the Page Erase and Page Write operation is addressing the same PROGRAM MEMORY 23 1 0 Z - POINTER BIT 0 ZPAGEMSB WORD ADDRESS WITHIN A PAGE PAGE ADDRESS WITHIN THE FLASH ZPCMSB INSTRUCTION WORD PAGE PCWORD[PAGEMSB:0]: 00 01 02 PAGEEND PAGE PCPAGE PCWORD PCMSB PAGEMSB PROGRAM COUNTER352 7593L–AVR–09/12 AT90USB64/128 page. See “Simple Assembly Code example for a Boot Loader” on page 355 for an assembly code example. 29.7.1 Performing page erase by SPM To execute Page Erase, set up the address in the Z-pointer, write “X0000011” to SPMCSR and execute SPM within four clock cycles after writing SPMCSR. The data in R1 and R0 is ignored. The page address must be written to PCPAGE in the Z-register. Other bits in the Z-pointer will be ignored during this operation. • Page Erase to the RWW section: The NRWW section can be read during the Page Erase • Page Erase to the NRWW section: The CPU is halted during the operation 29.7.2 Filling the Temporary Buffer (page loading) To write an instruction word, set up the address in the Z-pointer and data in R1:R0, write “00000001” to SPMCSR and execute SPM within four clock cycles after writing SPMCSR. The content of PCWORD in the Z-register is used to address the data in the temporary buffer. The temporary buffer will auto-erase after a Page Write operation or by writing the RWWSRE bit in SPMCSR. It is also erased after a system reset. Note that it is not possible to write more than one time to each address without erasing the temporary buffer. If the EEPROM is written in the middle of an SPM Page Load operation, all data loaded will be lost. 29.7.3 Performing a Page Write To execute Page Write, set up the address in the Z-pointer, write “X0000101” to SPMCSR and execute SPM within four clock cycles after writing SPMCSR. The data in R1 and R0 is ignored. The page address must be written to PCPAGE. Other bits in the Z-pointer must be written to zero during this operation. • Page Write to the RWW section: The NRWW section can be read during the Page Write • Page Write to the NRWW section: The CPU is halted during the operation 29.7.4 Using the SPM interrupt If the SPM interrupt is enabled, the SPM interrupt will generate a constant interrupt when the SPMEN bit in SPMCSR is cleared. This means that the interrupt can be used instead of polling the SPMCSR Register in software. When using the SPM interrupt, the Interrupt Vectors should be moved to the BLS section to avoid that an interrupt is accessing the RWW section when it is blocked for reading. How to move the interrupts is described in “Interrupts” on page 68. 29.7.5 Consideration while updating BLS Special care must be taken if the user allows the Boot Loader section to be updated by leaving Boot Lock bit11 unprogrammed. An accidental write to the Boot Loader itself can corrupt the entire Boot Loader, and further software updates might be impossible. If it is not necessary to change the Boot Loader software itself, it is recommended to program the Boot Lock bit11 to protect the Boot Loader software from any internal software changes. 29.7.6 Prevent reading the RWW section during self-programming During Self-Programming (either Page Erase or Page Write), the RWW section is always blocked for reading. The user software itself must prevent that this section is addressed during the self programming operation. The RWWSB in the SPMCSR will be set as long as the RWW section is busy. During Self-Programming the Interrupt Vector table should be moved to the BLS353 7593L–AVR–09/12 AT90USB64/128 as described in “Interrupts” on page 68, or the interrupts must be disabled. Before addressing the RWW section after the programming is completed, the user software must clear the RWWSB by writing the RWWSRE. See “Simple Assembly Code example for a Boot Loader” on page 355 for an example. 29.7.7 Setting the Boot Loader Lock bits by SPM To set the Boot Loader Lock bits, write the desired data to R0, write “X0001001” to SPMCSR and execute SPM within four clock cycles after writing SPMCSR. The only accessible Lock bits are the Boot Lock bits that may prevent the Application and Boot Loader section from any software update by the MCU. See Table 29-2 on page 347 and Table 29-3 on page 347 for how the different settings of the Boot Loader bits affect the Flash access. If bits 5..2 in R0 are cleared (zero), the corresponding Boot Lock bit will be programmed if an SPM instruction is executed within four cycles after BLBSET and SPMEN are set in SPMCSR. The Z-pointer is don’t care during this operation, but for future compatibility it is recommended to load the Z-pointer with 0x0001 (same as used for reading the lOck bits). For future compatibility it is also recommended to set bits 7, 6, 1, and 0 in R0 to “1” when writing the Lock bits. When programming the Lock bits the entire Flash can be read during the operation. 29.7.8 EEPROM Write prevents writing to SPMCSR Note that an EEPROM write operation will block all software programming to Flash. Reading the Fuses and Lock bits from software will also be prevented during the EEPROM write operation. It is recommended that the user checks the status bit (EEPE) in the EECR Register and verifies that the bit is cleared before writing to the SPMCSR Register. 29.7.9 Reading the Fuse and Lock bits from software It is possible to read both the Fuse and Lock bits from software. To read the Lock bits, load the Z-pointer with 0x0001 and set the BLBSET and SPMEN bits in SPMCSR. When an (E)LPM instruction is executed within three CPU cycles after the BLBSET and SPMEN bits are set in SPMCSR, the value of the Lock bits will be loaded in the destination register. The BLBSET and SPMEN bits will auto-clear upon completion of reading the Lock bits or if no (E)LPM instruction is executed within three CPU cycles or no SPM instruction is executed within four CPU cycles. When BLBSET and SPMEN are cleared, (E)LPM will work as described in the Instruction set Manual. The algorithm for reading the Fuse Low byte is similar to the one described above for reading the Lock bits. To read the Fuse Low byte, load the Z-pointer with 0x0000 and set the BLBSET and SPMEN bits in SPMCSR. When an (E)LPM instruction is executed within three cycles after the BLBSET and SPMEN bits are set in the SPMCSR, the value of the Fuse Low byte (FLB) will be loaded in the destination register as shown below. Refer to Table 30-5 on page 361 for a detailed description and mapping of the Fuse Low byte. Bit 7 6 5 4 3 2 1 0 R0 1 1 BLB12 BLB11 BLB02 BLB01 1 1 Bit 7 6 5 4 3 2 1 0 Rd – – BLB12 BLB11 BLB02 BLB01 LB2 LB1 Bit 7 6 5 4 3 2 1 0 Rd FLB7 FLB6 FLB5 FLB4 FLB3 FLB2 FLB1 FLB0354 7593L–AVR–09/12 AT90USB64/128 Similarly, when reading the Fuse High byte, load 0x0003 in the Z-pointer. When an (E)LPM instruction is executed within three cycles after the BLBSET and SPMEN bits are set in the SPMCSR, the value of the Fuse High byte (FHB) will be loaded in the destination register as shown below. Refer to Table 30-4 on page 361 for detailed description and mapping of the Fuse High byte. When reading the Extended Fuse byte, load 0x0002 in the Z-pointer. When an (E)LPM instruction is executed within three cycles after the BLBSET and SPMEN bits are set in the SPMCSR, the value of the Extended Fuse byte (EFB) will be loaded in the destination register as shown below. Refer to Table 30-3 on page 360 for detailed description and mapping of the Extended Fuse byte. Fuse and Lock bits that are programmed, will be read as zero. Fuse and Lock bits that are unprogrammed, will be read as one. 29.7.10 Reading the Signature Row from software To read the Signature Row from software, load the Z-pointer with the signature byte address given in Table 29-6 on page 354 and set the SIGRD and SPMEN bits in SPMCSR. When an LPM instruction is executed within three CPU cycles after the SIGRD and SPMEN bits are set in SPMCSR, the signature byte value will be loaded in the destination register. The SIGRD and SPMEN bits will auto-clear upon completion of reading the Signature Row Lock bits or if no LPM instruction is executed within three CPU cycles. When SIGRD and SPMEN are cleared, LPM will work as described in the Instruction set Manual. AT90USB64/128 includes a unique 10-bytes serial number located in the signature row. This unique serial number can be used as a USB serial number in the device enumeration process. The pointer addresses to access this unique serial number are given in Table 29-6 on page 354. Note: All other addresses are reserved for future use. 29.7.11 Preventing flash corruption During periods of low VCC, the Flash program can be corrupted because the supply voltage is too low for the CPU and the Flash to operate properly. These issues are the same as for board level systems using the Flash, and the same design solutions should be applied. A Flash program corruption can be caused by two situations when the voltage is too low. First, a regular write sequence to the Flash requires a minimum voltage to operate correctly. Secondly, Bit 7 6 5 4 3 2 1 0 Rd FHB7 FHB6 FHB5 FHB4 FHB3 FHB2 FHB1 FHB0 Bit 7 6 5 4 3 2 1 0 Rd – – – – – EFB2 EFB1 EFB0 Table 29-6. Signature Row addressing. Signature byte Z-pointer address Device Signature Byte 1 0x0000 Device Signature Byte 2 0x0002 Device Signature Byte 3 0x0004 RC Oscillator Calibration Byte 0x0001 Unique Serial Number From 0x000E to 0x0018355 7593L–AVR–09/12 AT90USB64/128 the CPU itself can execute instructions incorrectly, if the supply voltage for executing instructions is too low. Flash corruption can easily be avoided by following these design recommendations (one is sufficient): 1. If there is no need for a Boot Loader update in the system, program the Boot Loader Lock bits to prevent any Boot Loader software updates. 2. Keep the AVR RESET active (low) during periods of insufficient power supply voltage. This can be done by enabling the internal Brown-out Detector (BOD) if the operating voltage matches the detection level. If not, an external low VCC reset protection circuit can be used. If a reset occurs while a write operation is in progress, the write operation will be completed provided that the power supply voltage is sufficient. 3. Keep the AVR core in Power-down sleep mode during periods of low VCC. This will prevent the CPU from attempting to decode and execute instructions, effectively protecting the SPMCSR Register and thus the Flash from unintentional writes. 29.7.12 Programming time for flash when using SPM The calibrated RC Oscillator is used to time Flash accesses. Table 29-7 shows the typical programming time for Flash accesses from the CPU. 29.7.13 Simple Assembly Code example for a Boot Loader ;- the routine writes one page of data from RAM to Flash ; the first data location in RAM is pointed to by the Y-pointer ; the first data location in Flash is pointed to by the Z-pointer ;- error handling is not included ;- the routine must be placed inside the Boot space ; (at least the Do_spm sub routine). Only code inside NRWW section can ; be read during Self-Programming (Page Erase and Page Write). ;- registers used: r0, r1, temp1 (r16), temp2 (r17), looplo (r24), ; loophi (r25), spmcsrval (r20) ; storing and restoring of registers is not included in the routine ; register usage can be optimized at the expense of code size ;- it is assumed that either the interrupt table is moved to the Boot ; loader section or that the interrupts are disabled. .equ PAGESIZEB = PAGESIZE*2 ;PAGESIZEB is page size in BYTES, not words .org SMALLBOOTSTART Write_page: ; Page Erase ldi spmcsrval, (1< 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck >= 12MHz High: > 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck >= 12MHz 30.8.1 Serial programming algorithm When writing serial data to the Atmel AT90USB64/128, data is clocked on the rising edge of SCK. When reading data from the AT90USB64/128, data is clocked on the falling edge of SCK. See Figure 30-11 on page 375 for timing details. To program and verify the AT90USB64/128 in the serial programming mode, the following sequence is recommended (See four byte instruction formats in Table 30-16 on page 376): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to “0”. In some systems, the programmer can not guarantee that SCK is held low during power-up. In this case, RESET must be given a positive pulse of at least two CPU clock cycles duration after SCK has been set to “0”. 2. Wait for at least 20ms and enable serial programming by sending the Programming Enable serial instruction to pin PDI. Table 30-14. Pin mapping serial programming. Symbol Pins (TQFP-64) I/O Description PDI PB2 I Serial Data in PDO PB3 O Serial Data out SCK PB1 I Serial Clock VCC GND XTAL1 SCK PDO PDI RESET +1.8 - 5.5V AVCC +1.8 - 5.5V(2)375 7593L–AVR–09/12 AT90USB64/128 3. The serial programming instructions will not work if the communication is out of synchronization. When in sync. the second byte (0x53), will echo back when issuing the third byte of the Programming Enable instruction. Whether the echo is correct or not, all four bytes of the instruction must be transmitted. If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command. 4. The Flash is programmed one page at a time. The memory page is loaded one byte at a time by supplying the 7 LSB of the address and data together with the Load Program Memory Page instruction. To ensure correct loading of the page, the data low byte must be loaded before data high byte is applied for a given address. The Program Memory Page is stored by loading the Write Program Memory Page instruction with the address lines 15..8. Before issuing this command, make sure the instruction Load Extended Address Byte has been used to define the MSB of the address. The extended address byte is stored until the command is re-issued, i.e., the command needs only be issued for the first page, and when crossing the 64KWord boundary. If polling (RDY/BSY) is not used, the user must wait at least tWD_FLASH before issuing the next page. (See Table 30- 15.) Accessing the serial programming interface before the Flash write operation completes can result in incorrect programming. 5. The EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. If polling is not used, the user must wait at least tWD_EEPROM before issuing the next byte. (See Table 30-15.) In a chip erased device, no 0xFFs in the data file(s) need to be programmed. 6. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output PDO. When reading the Flash memory, use the instruction Load Extended Address Byte to define the upper address byte, which is not included in the Read Program Memory instruction. The extended address byte is stored until the command is re-issued, that is, the command needs only be issued for the first page, and when crossing the 64KWord boundary. 7. At the end of the programming session, RESET can be set high to commence normal operation. 8. Power-off sequence (if needed): Set RESET to “1”. Turn VCC power off. Figure 30-11. Serial programming waveforms. Table 30-15. Minimum wait delay before writing the next Flash or EEPROM location. Symbol Minimum wait delay tWD_FLASH 4.5ms tWD_EEPROM 9.0ms tWD_ERASE 9.0ms MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUT376 7593L–AVR–09/12 AT90USB64/128 Table 30-16. Serial programming instruction set. Instruction Instruction format Byte 1 Byte 2 Byte 3 Byte 4 Operation Programming Enable 1010 1100 0101 0011 xxxx xxxx xxxx xxxx Enable Serial Programming after RESET goes low. Chip Erase 1010 1100 100x xxxx xxxx xxxx xxxx xxxx Chip Erase EEPROM and Flash. Load Extended Address Byte 0100 1101 0000 0000 cccc cccc xxxx xxxx Defines Extended Address Byte for Read Program Memory and Write Program Memory Page. Read Program Memory 0010 H000 aaaa aaaa bbbb bbbb oooo oooo Read H (high or low) data o from Program memory at word address c:a:b. Load Program Memory Page 0100 H000 xxxx xxxx xxbb bbbb iiii iiii Write H (high or low) data i to Program Memory page at word address b. Data low byte must be loaded before Data high byte is applied within the same address. Write Program Memory Page 0100 1100 aaaa aaaa bbxx xxxx xxxx xxxx Write Program Memory Page at address c:a:b. Read EEPROM Memory 1010 0000 0000 aaaa bbbb bbbb oooo oooo Read data o from EEPROM memory at address a:b. Write EEPROM Memory 1100 0000 0000 aaaa bbbb bbbb iiii iiii Write data i to EEPROM memory at address a:b. Load EEPROM Memory Page (page access) 1100 0001 0000 0000 0000 00bb iiii iiii Load data i to EEPROM memory page buffer. After data is loaded, program EEPROM page. Write EEPROM Memory Page (page access) 1100 0010 0000 aaaa bbbb bb00 xxxx xxxx Write EEPROM page at address a:b. Read Lock bits 0101 1000 0000 0000 xxxx xxxx xxoo oooo Read Lock bits. “0” = programmed, “1” = unprogrammed. See Table 30-1 on page 359 for details. Write Lock bits 1010 1100 111x xxxx xxxx xxxx 11ii iiii Write Lock bits. Set bits = “0” to program Lock bits. See Table 30-1 on page 359 for details. Read Signature Byte 0011 0000 000x xxxx xxxx xxbb oooo oooo Read Signature Byte o at address b. Write Fuse bits 1010 1100 1010 0000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. Write Fuse High bits 1010 1100 1010 1000 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. Write Extended Fuse Bits 1010 1100 1010 0100 xxxx xxxx iiii iiii Set bits = “0” to program, “1” to unprogram. See Table 30-3 on page 360 for details. Read Fuse bits 0101 0000 0000 0000 xxxx xxxx oooo oooo Read Fuse bits. “0” = programmed, “1” = unprogrammed. Read Fuse High bits 0101 1000 0000 1000 xxxx xxxx oooo oooo Read Fuse High bits. “0” = programmed, “1” = unprogrammed. 377 7593L–AVR–09/12 AT90USB64/128 Note: a = address high bits, b = address low bits, c = address extended bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care. 30.8.2 Serial programming characteristics For characteristics of the Serial Programming module see “SPI timing characteristics” on page 395. 30.9 Programming via the JTAG interface Programming through the JTAG interface requires control of the four JTAG specific pins: TCK, TMS, TDI, and TDO. Control of the reset and clock pins is not required. To be able to use the JTAG interface, the JTAGEN Fuse must be programmed. The device is default shipped with the fuse programmed. In addition, the JTD bit in MCUCR must be cleared. Alternatively, if the JTD bit is set, the external reset can be forced low. Then, the JTD bit will be cleared after two chip clocks, and the JTAG pins are available for programming. This provides a means of using the JTAG pins as normal port pins in Running mode while still allowing In-System Programming via the JTAG interface. Note that this technique can not be used when using the JTAG pins for Boundary-scan or On-chip Debug. In these cases the JTAG pins must be dedicated for this purpose. During programming the clock frequency of the TCK Input must be less than the maximum frequency of the chip. The System Clock Prescaler can not be used to divide the TCK Clock Input into a sufficiently low frequency. As a definition in this datasheet, the LSB is shifted in and out first of all Shift Registers. 30.9.1 Programming specific JTAG instructions The Instruction Register is 4-bit wide, supporting up to 16 instructions. The JTAG instructions useful for programming are listed below. The OPCODE for each instruction is shown behind the instruction name in hex format. The text describes which Data Register is selected as path between TDI and TDO for each instruction. The Run-Test/Idle state of the TAP controller is used to generate internal clocks. It can also be used as an idle state between JTAG sequences. The state machine sequence for changing the instruction word is shown in Figure 30-12 on page 378. Read Extended Fuse Bits 0101 0000 0000 1000 xxxx xxxx oooo oooo Read Extended Fuse bits. “0” = programmed, “1” = unprogrammed. See Table 30-3 on page 360 for details. Read Calibration Byte 0011 1000 000x xxxx 0000 0000 oooo oooo Read Calibration Byte Poll RDY/BSY 1111 0000 0000 0000 xxxx xxxx xxxx xxxo If o = “1”, a programming operation is still busy. Wait until this bit returns to “0” before applying another command. Table 30-16. Serial programming instruction set. (Continued) Instruction Instruction format Byte 1 Byte 2 Byte 3 Byte 4 Operation378 7593L–AVR–09/12 AT90USB64/128 Figure 30-12. State machine sequence for changing the instruction word. 30.9.2 AVR_RESET (0xC) The AVR specific public JTAG instruction for setting the AVR device in the Reset mode or taking the device out from the Reset mode. The TAP controller is not reset by this instruction. The one bit Reset Register is selected as Data Register. Note that the reset will be active as long as there is a logic “one” in the Reset Chain. The output from this chain is not latched. The active states are: • Shift-DR: The Reset Register is shifted by the TCK input 30.9.3 PROG_ENABLE (0x4) The AVR specific public JTAG instruction for enabling programming via the JTAG port. The 16- bit Programming Enable Register is selected as Data Register. The active states are the following: • Shift-DR: The programming enable signature is shifted into the Data Register • Update-DR: The programming enable signature is compared to the correct value, and Programming mode is entered if the signature is valid Test-logic-reset Run-test/idle Shift-DR Exit1-DR Pause-DR Exit2-DR Update-DR Select-IR scan Capture-IR Shift-IR Exit1-IR Pause-IR Exit2-IR Update-IR Select-DR scan Capture-DR 0 1 0 11 1 0 0 0 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 0 0 1 1379 7593L–AVR–09/12 AT90USB64/128 30.9.4 PROG_COMMANDS (0x5) The AVR specific public JTAG instruction for entering programming commands via the JTAG port. The 15-bit Programming Command Register is selected as Data Register. The active states are the following: • Capture-DR: The result of the previous command is loaded into the Data Register • Shift-DR: The Data Register is shifted by the TCK input, shifting out the result of the previous command and shifting in the new command • Update-DR: The programming command is applied to the Flash inputs • Run-Test/Idle: One clock cycle is generated, executing the applied command 30.9.5 PROG_PAGELOAD (0x6) The AVR specific public JTAG instruction to directly load the Flash data page via the JTAG port. An 8-bit Flash Data Byte Register is selected as the Data Register. This is physically the eight LSBs of the Programming Command Register. The active states are the following: • Shift-DR: The Flash Data Byte Register is shifted by the TCK input • Update-DR: The content of the Flash Data Byte Register is copied into a temporary register. A write sequence is initiated that within 11 TCK cycles loads the content of the temporary register into the Flash page buffer. The AVR automatically alternates between writing the low and the high byte for each new Update-DR state, starting with the low byte for the first Update-DR encountered after entering the PROG_PAGELOAD command. The Program Counter is pre-incriminated before writing the low byte, except for the first written byte. This ensures that the first data is written to the address set up by PROG_COMMANDS, and loading the last location in the page buffer does not make the program counter increment into the next page 30.9.6 PROG_PAGEREAD (0x7) The AVR specific public JTAG instruction to directly capture the Flash content via the JTAG port. An 8-bit Flash Data Byte Register is selected as the Data Register. This is physically the 8 LSBs of the Programming Command Register. The active states are the following: • Capture-DR: The content of the selected Flash byte is captured into the Flash Data Byte Register. The AVR automatically alternates between reading the low and the high byte for each new Capture-DR state, starting with the low byte for the first Capture-DR encountered after entering the PROG_PAGEREAD command. The Program Counter is post-incremented after reading each high byte, including the first read byte. This ensures that the first data is captured from the first address set up by PROG_COMMANDS, and reading the last location in the page makes the program counter increment into the next page • Shift-DR: The Flash Data Byte Register is shifted by the TCK input 30.9.7 Data Registers The Data Registers are selected by the JTAG instruction registers described in section “Programming specific JTAG instructions” on page 377. The Data Registers relevant for programming operations are: • Reset Register • Programming Enable Register • Programming Command Register • Flash Data Byte Register380 7593L–AVR–09/12 AT90USB64/128 30.9.8 Reset Register The Reset Register is a Test Data Register used to reset the part during programming. It is required to reset the part before entering Programming mode. A high value in the Reset Register corresponds to pulling the external reset low. The part is reset as long as there is a high value present in the Reset Register. Depending on the Fuse settings for the clock options, the part will remain reset for a Reset Time-out period (refer to “Clock sources” on page 41) after releasing the Reset Register. The output from this Data Register is not latched, so the reset will take place immediately, as shown in Figure 9-1 on page 58. 30.9.9 Programming Enable Register The Programming Enable Register is a 16-bit register. The contents of this register is compared to the programming enable signature, binary code 0b1010_0011_0111_0000. When the contents of the register is equal to the programming enable signature, programming via the JTAG port is enabled. The register is reset to 0 on Power-on Reset, and should always be reset when leaving Programming mode. Figure 30-13. Programming enable register. 30.9.10 Programming Command Register The Programming Command Register is a 15-bit register. This register is used to serially shift in programming commands, and to serially shift out the result of the previous command, if any. The JTAG Programming Instruction Set is shown in Table 30-17 on page 382. The state sequence when shifting in the programming commands is illustrated in Figure 30-15 on page 385. TDI TDO D A T A = D Q ClockDR & PROG_ENABLE Programming enable 0xA370381 7593L–AVR–09/12 AT90USB64/128 Figure 30-14. Programming Command register. TDI TDO S T R O B E S A D D R E S S / D A T A Flash EEPROM fuses lock bits382 7593L–AVR–09/12 AT90USB64/128 Table 30-17. JTAG programming instruction set. a = address high bits, b = address low bits, c = address extended bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care. Instruction TDI sequence TDO sequence Notes 1a. Chip Erase 0100011_10000000 0110001_10000000 0110011_10000000 0110011_10000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx 1b. Poll for Chip Erase Complete 0110011_10000000 xxxxxox_xxxxxxxx (2) 2a. Enter Flash Write 0100011_00010000 xxxxxxx_xxxxxxxx 2b. Load Address Extended High Byte 0001011_cccccccc xxxxxxx_xxxxxxxx (10) 2c. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx 2d. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 2e. Load Data Low Byte 0010011_iiiiiiii xxxxxxx_xxxxxxxx 2f. Load Data High Byte 0010111_iiiiiiii xxxxxxx_xxxxxxxx 2g. Latch Data 0110111_00000000 1110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 2h. Write Flash Page 0110111_00000000 0110101_00000000 0110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 2i. Poll for Page Write Complete 0110111_00000000 xxxxxox_xxxxxxxx (2) 3a. Enter Flash Read 0100011_00000010 xxxxxxx_xxxxxxxx 3b. Load Address Extended High Byte 0001011_cccccccc xxxxxxx_xxxxxxxx (10) 3c. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx 3d. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 3e. Read Data Low and High Byte 0110010_00000000 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo xxxxxxx_oooooooo Low byte High byte 4a. Enter EEPROM Write 0100011_00010001 xxxxxxx_xxxxxxxx 4b. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx (10) 4c. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 4d. Load Data Byte 0010011_iiiiiiii xxxxxxx_xxxxxxxx 4e. Latch Data 0110111_00000000 1110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 4f. Write EEPROM Page 0110011_00000000 0110001_00000000 0110011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1)383 7593L–AVR–09/12 AT90USB64/128 4g. Poll for Page Write Complete 0110011_00000000 xxxxxox_xxxxxxxx (2) 5a. Enter EEPROM Read 0100011_00000011 xxxxxxx_xxxxxxxx 5b. Load Address High Byte 0000111_aaaaaaaa xxxxxxx_xxxxxxxx (10) 5c. Load Address Low Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 5d. Read Data Byte 0110011_bbbbbbbb 0110010_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 6a. Enter Fuse Write 0100011_01000000 xxxxxxx_xxxxxxxx 6b. Load Data Low Byte (6) 0010011_iiiiiiii xxxxxxx_xxxxxxxx (3) 6c. Write Fuse Extended Byte 0111011_00000000 0111001_00000000 0111011_00000000 0111011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 6d. Poll for Fuse Write Complete 0110111_00000000 xxxxxox_xxxxxxxx (2) 6e. Load Data Low Byte (7) 0010011_iiiiiiii xxxxxxx_xxxxxxxx (3) 6f. Write Fuse High Byte 0110111_00000000 0110101_00000000 0110111_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 6g. Poll for Fuse Write Complete 0110111_00000000 xxxxxox_xxxxxxxx (2) 6h. Load Data Low Byte (7) 0010011_iiiiiiii xxxxxxx_xxxxxxxx (3) 6i. Write Fuse Low Byte 0110011_00000000 0110001_00000000 0110011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 6j. Poll for Fuse Write Complete 0110011_00000000 xxxxxox_xxxxxxxx (2) 7a. Enter Lock Bit Write 0100011_00100000 xxxxxxx_xxxxxxxx 7b. Load Data Byte (9) 0010011_11iiiiii xxxxxxx_xxxxxxxx (4) 7c. Write Lock Bits 0110011_00000000 0110001_00000000 0110011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx (1) 7d. Poll for Lock Bit Write complete 0110011_00000000 xxxxxox_xxxxxxxx (2) 8a. Enter Fuse/Lock Bit Read 0100011_00000100 xxxxxxx_xxxxxxxx 8b. Read Extended Fuse Byte (6) 0111010_00000000 0111011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 8c. Read Fuse High Byte (7) 0111110_00000000 0111111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo Table 30-17. JTAG programming instruction set. (Continued) a = address high bits, b = address low bits, c = address extended bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care. Instruction TDI sequence TDO sequence Notes384 7593L–AVR–09/12 AT90USB64/128 Notes: 1. This command sequence is not required if the seven MSB are correctly set by the previous command sequence (which is normally the case). 2. Repeat until o = “1”. 3. Set bits to “0” to program the corresponding Fuse, “1” to un-program the Fuse. 4. Set bits to “0” to program the corresponding Lock bit, “1” to leave the Lock bit unchanged. 5. “0” = programmed, “1” = un-programmed. 6. The bit mapping for Fuses Extended byte is listed in Table 30-3 on page 360. 7. The bit mapping for Fuses High byte is listed in Table 30-4 on page 361. 8. The bit mapping for Fuses Low byte is listed in Table 30-5 on page 361. 9. The bit mapping for Lock bits byte is listed in Table 30-1 on page 359. 10. Address bits exceeding PCMSB and EEAMSB (Table 30-11 on page 364 and Table 30-12 on page 365) are don’t care. 11. All TDI and TDO sequences are represented by binary digits (0b...). 8d. Read Fuse Low Byte (8) 0110010_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 8e. Read Lock Bits (9) 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxoooooo (5) 8f. Read Fuses and Lock Bits 0111010_00000000 0111110_00000000 0110010_00000000 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo xxxxxxx_oooooooo xxxxxxx_oooooooo xxxxxxx_oooooooo (5) Fuse Ext. byte Fuse High byte Fuse Low byte Lock bits 9a. Enter Signature Byte Read 0100011_00001000 xxxxxxx_xxxxxxxx 9b. Load Address Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 9c. Read Signature Byte 0110010_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 10a. Enter Calibration Byte Read 0100011_00001000 xxxxxxx_xxxxxxxx 10b. Load Address Byte 0000011_bbbbbbbb xxxxxxx_xxxxxxxx 10c. Read Calibration Byte 0110110_00000000 0110111_00000000 xxxxxxx_xxxxxxxx xxxxxxx_oooooooo 11a. Load No Operation Command 0100011_00000000 0110011_00000000 xxxxxxx_xxxxxxxx xxxxxxx_xxxxxxxx Table 30-17. JTAG programming instruction set. (Continued) a = address high bits, b = address low bits, c = address extended bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in, x = don’t care. Instruction TDI sequence TDO sequence Notes385 7593L–AVR–09/12 AT90USB64/128 Figure 30-15. State machine sequence for changing/reading the data word. 30.9.11 Flash Data Byte Register The Flash Data Byte Register provides an efficient way to load the entire Flash page buffer before executing Page Write, or to read out/verify the content of the Flash. A state machine sets up the control signals to the Flash and senses the strobe signals from the Flash, thus only the data words need to be shifted in/out. The Flash Data Byte Register actually consists of the 8-bit scan chain and a 8-bit temporary register. During page load, the Update-DR state copies the content of the scan chain over to the temporary register and initiates a write sequence that within 11 TCK cycles loads the content of the temporary register into the Flash page buffer. The AVR automatically alternates between writing the low and the high byte for each new Update-DR state, starting with the low byte for the first Update-DR encountered after entering the PROG_PAGELOAD command. The Program Counter is pre-incremented before writing the low byte, except for the first written byte. This ensures that the first data is written to the address set up by PROG_COMMANDS, and loading the last location in the page buffer does not make the Program Counter increment into the next page. During Page Read, the content of the selected Flash byte is captured into the Flash Data Byte Register during the Capture-DR state. The AVR automatically alternates between reading the low and the high byte for each new Capture-DR state, starting with the low byte for the first CapTest-logic-reset Run-test/idle Shift-DR Exit1-DR Pause-DR Exit2-DR Update-DR Select-IR scan Capture-IR Shift-IR Exit1-IR Pause-IR Exit2-IR Update-IR Select-DR scan Capture-DR 0 1 0 11 1 0 0 0 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 0 0 1 1386 7593L–AVR–09/12 AT90USB64/128 ture-DR encountered after entering the PROG_PAGEREAD command. The Program Counter is post-incremented after reading each high byte, including the first read byte. This ensures that the first data is captured from the first address set up by PROG_COMMANDS, and reading the last location in the page makes the program counter increment into the next page. Figure 30-16. Flash Data Byte Register. The state machine controlling the Flash Data Byte Register is clocked by TCK. During normal operation in which eight bits are shifted for each Flash byte, the clock cycles needed to navigate through the TAP controller automatically feeds the state machine for the Flash Data Byte Register with sufficient number of clock pulses to complete its operation transparently for the user. However, if too few bits are shifted between each Update-DR state during page load, the TAP controller should stay in the Run-Test/Idle state for some TCK cycles to ensure that there are at least 11 TCK cycles between each Update-DR state. 30.9.12 Programming algorithm All references below of type “1a”, “1b”, and so on, refer to Table 30-17 on page 382. 30.9.13 Entering Programming mode 1. Enter JTAG instruction AVR_RESET and shift 1 in the Reset Register. 2. Enter instruction PROG_ENABLE and shift 0b1010_0011_0111_0000 in the Programming Enable Register. 30.9.14 Leaving Programming mode 1. Enter JTAG instruction PROG_COMMANDS. 2. Disable all programming instructions by using no operation instruction 11a. 3. Enter instruction PROG_ENABLE and shift 0b0000_0000_0000_0000 in the programming Enable Register. 4. Enter JTAG instruction AVR_RESET and shift 0 in the Reset Register. TDI TDO D A T A Flash EEPROM fuses lock bits STROBES ADDRESS State machine387 7593L–AVR–09/12 AT90USB64/128 30.9.15 Performing Chip Erase 1. Enter JTAG instruction PROG_COMMANDS. 2. Start Chip Erase using programming instruction 1a. 3. Poll for Chip Erase complete using programming instruction 1b, or wait for tWLRH_CE (refer to Table 30-13 on page 373). 30.9.16 Programming the Flash Before programming the Flash a Chip Erase must be performed, see “Performing Chip Erase” on page 387. 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash write using programming instruction 2a. 3. Load address Extended High byte using programming instruction 2b. 4. Load address High byte using programming instruction 2c. 5. Load address Low byte using programming instruction 2d. 6. Load data using programming instructions 2e, 2f and 2g. 7. Repeat steps 5 and 6 for all instruction words in the page. 8. Write the page using programming instruction 2h. 9. Poll for Flash write complete using programming instruction 2i, or wait for tWLRH (refer to Table 30-13 on page 373). 10. Repeat steps 3 to 9 until all data have been programmed. A more efficient data transfer can be achieved using the PROG_PAGELOAD instruction: 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash write using programming instruction 2a. 3. Load the page address using programming instructions 2b, 2c and 2d. PCWORD (refer to Table 30-11 on page 364) is used to address within one page and must be written as 0. 4. Enter JTAG instruction PROG_PAGELOAD. 5. Load the entire page by shifting in all instruction words in the page byte-by-byte, starting with the LSB of the first instruction in the page and ending with the MSB of the last instruction in the page. Use Update-DR to copy the contents of the Flash Data Byte Register into the Flash page location and to auto-increment the Program Counter before each new word. 6. Enter JTAG instruction PROG_COMMANDS. 7. Write the page using programming instruction 2h. 8. Poll for Flash write complete using programming instruction 2i, or wait for tWLRH (refer to Table 30-13 on page 373). 9. Repeat steps 3 to 8 until all data have been programmed. 30.9.17 Reading the Flash 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash read using programming instruction 3a. 3. Load address using programming instructions 3b, 3c and 3d. 4. Read data using programming instruction 3e. 5. Repeat steps 3 and 4 until all data have been read. A more efficient data transfer can be achieved using the PROG_PAGEREAD instruction:388 7593L–AVR–09/12 AT90USB64/128 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Flash read using programming instruction 3a. 3. Load the page address using programming instructions 3b, 3c and 3d. PCWORD (refer to Table 30-11 on page 364) is used to address within one page and must be written as 0. 4. Enter JTAG instruction PROG_PAGEREAD. 5. Read the entire page (or Flash) by shifting out all instruction words in the page (or Flash), starting with the LSB of the first instruction in the page (Flash) and ending with the MSB of the last instruction in the page (Flash). The Capture-DR state both captures the data from the Flash, and also auto-increments the program counter after each word is read. Note that Capture-DR comes before the shift-DR state. Hence, the first byte which is shifted out contains valid data. 6. Enter JTAG instruction PROG_COMMANDS. 7. Repeat steps 3 to 6 until all data have been read. 30.9.18 Programming the EEPROM Before programming the EEPROM a Chip Erase must be performed, see “Performing Chip Erase” on page 387. 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable EEPROM write using programming instruction 4a. 3. Load address High byte using programming instruction 4b. 4. Load address Low byte using programming instruction 4c. 5. Load data using programming instructions 4d and 4e. 6. Repeat steps 4 and 5 for all data bytes in the page. 7. Write the data using programming instruction 4f. 8. Poll for EEPROM write complete using programming instruction 4g, or wait for tWLRH (refer to Table 30-13 on page 373). 9. Repeat steps 3 to 8 until all data have been programmed. Note that the PROG_PAGELOAD instruction can not be used when programming the EEPROM. 30.9.19 Reading the EEPROM 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable EEPROM read using programming instruction 5a. 3. Load address using programming instructions 5b and 5c. 4. Read data using programming instruction 5d. 5. Repeat steps 3 and 4 until all data have been read. Note that the PROG_PAGEREAD instruction can not be used when reading the EEPROM. 30.9.20 Programming the Fuses 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Fuse write using programming instruction 6a. 3. Load data high byte using programming instructions 6b. A bit value of “0” will program the corresponding fuse, a “1” will un-program the fuse. 4. Write Fuse High byte using programming instruction 6c. 5. Poll for Fuse write complete using programming instruction 6d, or wait for tWLRH (refer to Table 30-13 on page 373).389 7593L–AVR–09/12 AT90USB64/128 6. Load data low byte using programming instructions 6e. A “0” will program the fuse, a “1” will unprogram the fuse. 7. Write Fuse low byte using programming instruction 6f. 8. Poll for Fuse write complete using programming instruction 6g, or wait for tWLRH (refer to Table 30-13 on page 373). 30.9.21 Programming the Lock Bits 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Lock bit write using programming instruction 7a. 3. Load data using programming instructions 7b. A bit value of “0” will program the corresponding lock bit, a “1” will leave the lock bit unchanged. 4. Write Lock bits using programming instruction 7c. 5. Poll for Lock bit write complete using programming instruction 7d, or wait for tWLRH (refer to Table 30-13 on page 373). 30.9.22 Reading the Fuses and Lock Bits 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Fuse/Lock bit read using programming instruction 8a. 3. To read all Fuses and Lock bits, use programming instruction 8e. To only read Fuse High byte, use programming instruction 8b. To only read Fuse Low byte, use programming instruction 8c. To only read Lock bits, use programming instruction 8d. 30.9.23 Reading the Signature Bytes 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Signature byte read using programming instruction 9a. 3. Load address 0x00 using programming instruction 9b. 4. Read first signature byte using programming instruction 9c. 5. Repeat steps 3 and 4 with address 0x01 and address 0x02 to read the second and third signature bytes, respectively. 30.9.24 Reading the Calibration Byte 1. Enter JTAG instruction PROG_COMMANDS. 2. Enable Calibration byte read using programming instruction 10a. 3. Load address 0x00 using programming instruction 10b. 4. Read the calibration byte using programming instruction 10c.390 7593L–AVR–09/12 AT90USB64/128 31. Electrical characteristics for Atmel AT90USB64/128 31.1 Absolute maximum ratings* 31.2 DC characteristics Operating temperature..................................... -40°C to +85°C *NOTICE: Stresses beyond those listed under “Absolute maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage temperature...................................... -65°C to +150°C Voltage on any pin except RESET and VBUS with respect to ground (7) .............................-0.5V to VCC+0.5V Voltage on RESET with respect to ground ......-0.5V to +13.0V Voltage on VBUS with respect to ground...........-0.5V to +6.0V Maximum operating voltage............................................ +6.0V DC current per I/O pin.................................................. 40.0mA DC current VCC and GND pins .................................. 200.0mA TA = -40°C to 85°C, VCC = 2.7V to 5.5V (unless otherwise noted). Symbol Parameter Condition Min. (5) Typ. Max. (5) Units VIL Input Low Voltage,Except XTAL1 and Reset pin VCC = 2.7V - 5.5V -0.5 0.2VCC (1) V VIL1 Input Low Voltage, XTAL1 pin VCC = 2.7V - 5.5V -0.5 0.1VCC (1) VIL2 Input Low Voltage, RESET pin VCC = 2.7V - 5.5V -0.5 0.1VCC (1) VIH Input High Voltage, Except XTAL1 and RESET pins VCC = 2.7V - 5.5V 0.6VCC (2) VCC + 0.5 VIH1 Input High Voltage, XTAL1 pin VCC = 2.7V - 5.5V 0.7VCC (2) VCC + 0.5 VIH2 Input High Voltage, RESET pin VCC = 2.7V - 5.5V 0.9VCC (2) VCC + 0.5 VOL Output Low Voltage (3) IOL = 10mA, VCC = 5V IOL = 5mA, VCC = 3V 0.3 0.2 0.7 0.5 VOH Output High Voltage (4) IOH = -20mA, VCC = 5V IOH = -10mA, VCC = 3V 4.2 2.3 4.5 2.6 IIL Input Leakage Current I/O Pin VCC = 5.5V, pin low (absolute value) 1 µA IIH Input Leakage Current I/O Pin VCC = 5.5V, pin high (absolute value) 1 RRST Reset Pull-up Resistor 30 60 kΩ RPU I/O Pin Pull-up Resistor 20 50391 7593L–AVR–09/12 AT90USB64/128 Note: 1. "Max" means the highest value where the pin is guaranteed to be read as low 2. "Min" means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed: Atmel AT90USB64/128: 1.)The sum of all IOL, for ports A0-A7, G2, C4-C7 should not exceed 100mA. 2.)The sum of all IOL, for ports C0-C3, G0-G1, D0-D7 should not exceed 100mA. 3.)The sum of all IOL, for ports G3-G5, B0-B7, E0-E7 should not exceed 100mA. 4.)The sum of all IOL, for ports F0-F7 should not exceed 100mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed: AT90USB64/128: 1)The sum of all IOH, for ports A0-A7, G2, C4-C7 should not exceed 100mA. 2)The sum of all IOH, for ports C0-C3, G0-G1, D0-D7 should not exceed 100mA. 3)The sum of all IOH, for ports G3-G5, B0-B7, E0-E7 should not exceed 100mA. 4)The sum of all IOH, for ports F0-F7 should not exceed 100mA. 5. All DC Characteristics contained in this datasheet are based on simulation and characterization of other AVR microcontrollers manufactured in the same process technology. These values are preliminary values representing design targets, and will be updated after characterization of actual silicon 6. Values with “PRR1 – Power Reduction Register 1” disabled (0x00). ICC Power Supply Current (6) Active 4MHz, VCC = 3V (AT90USB64/128) 2.5 5 mA Active 8MHz, VCC = 3V (AT90USB64/128) 5 10 Active 8MHz, VCC = 5V (AT90USB64/128) 10 18 Active 16MHz, VCC = 5V (AT90USB64/128) 19 30 Icc Power-down mode WDT enabled, BOD enabled, VCC = 3V, 25°C 30 µA WDT enabled, BOD disabled, VCC = 3V, 25°C 10 WDT disabled, BOD disabled, VCC = 3V, 25°C 2 VACIO Analog Comparator Input Offset Voltage VCC = 5V Vin = VCC/2 10 40 mV IACLK Analog Comparator Input Leakage Current VCC = 5V Vin = VCC/2 -50 50 nA tACID Analog Comparator Propagation Delay VCC = 2.7V VCC = 4.0V 750 500 ns Iq USB Regulator Quiescent Current UVCC >3.6V, I = 0mA 10 30 µA Vusb USB Regulator Output Voltage (Ucap) UVCC >3.6V, I = 40mA (8) 3.0 3.3 3.5 V TA = -40°C to 85°C, VCC = 2.7V to 5.5V (unless otherwise noted). (Continued) Symbol Parameter Condition Min. (5) Typ. Max. (5) Units392 7593L–AVR–09/12 AT90USB64/128 7. As specified on the USB Electrical chapter of USB Specifications 2.0, the D+/D- pads can withstand voltages down to -1V applied through a 39Ω resistor 8. USB Peripheral consumes up to 50mA from the regulator or UVCC pin when USB is used at full-load 31.3 External clock drive waveforms Figure 31-1. External clock drive waveforms. 31.4 External clock drive Note: All DC characteristics contained in this datasheet are based on simulation and characterization of other AVR microcontrollers manufactured in the same process technology. These values are preliminary values representing design targets, and will be updated after characterization of actual silicon. 31.5 Maximum speed vs. VCC Maximum frequency is depending on VCC. As shown in Figure 31-2 on page 393, the maximum frequency vs. VCC curve is linear between 2.7V < VCC < 5.5V. VIL1 VIH1 Table 31-1. External clock drive. Symbol Parameter VCC=1.8-5.5V VCC=2.7-5.5V VCC=4.5-5.5V Min. Max. Min. Max. Min. Max. Units 1/tCLCL Oscillator Frequency 0 2 0 8 0 16 MHz tCLCL Clock Period 500 125 62.5 tCHCX High Time 200 50 25 ns t CLCX Low Time 200 50 25 tCLCH Rise Time 2.0 1.6 0.5 μs tCHCL Fall Time 2.0 1.6 0.5 ΔtCLCL Change in period from one clock cycle to the next 2 2 2%393 7593L–AVR–09/12 AT90USB64/128 Figure 31-2. Maximum frequency vs. VCC, Atmel AT90USB64/128. 31.6 2-wire serial interface characteristics Table 31-2 describes the requirements for devices connected to the 2-wire Serial Bus. The AT90USB64/128 2-wire Serial Interface meets or exceeds these requirements under the noted conditions. Timing symbols refer to Figure 31-3 on page 394. 16MHz 8MHz Table 31-2. 2-wire serial bus requirements. Symbol Parameter Condition Min Max Units VIL Input Low-voltage -0.5 0.3 VCC V VIH Input High-voltage 0.7 VCC VCC + 0.5 Vhys (1) Hysteresis of Schmitt Trigger Inputs 0.05 VCC (2) – VOL (1) Output Low-voltage 3mA sink current 0 0.4 tr (1) Rise Time for both SDA and SCL 20 + 0.1Cb (3)(2) 300 tof ns (1) Output Fall Time from VIHmin to VILmax 10pF < Cb < 400pF (3) 20 + 0.1Cb (3)(2) 250 tSP (1) Spikes Suppressed by Input Filter 0 50 (2) Ii Input Current each I/O Pin 0.1VCC < Vi < 0.9VCC -10 10 µA Ci (1) Capacitance for each I/O Pin – 10 pF fSCL SCL Clock Frequency fCK (4) > max(16fSCL, 250kHz) (5) 0 400 kHz Rp Value of Pull-up resistor fSCL ≤ 100kHz fSCL > 100kHz VCC – 0.4V 3mA ---------------------------- 1000ns Cb ------------------- Ω VCC – 0.4V 3mA ---------------------------- 300ns Cb ----------------394 7593L–AVR–09/12 AT90USB64/128 Notes: 1. In Atmel AT90USB64/128, this parameter is characterized and not 100% tested. 2. Required only for fSCL >100kHz. 3. Cb = capacitance of one bus line in pF. 4. fCK = CPU clock frequency 5. This requirement applies to all AT90USB64/128 2-wire Serial Interface operation. Other devices connected to the 2-wire Serial Bus need only obey the general fSCL requirement. 6. The actual low period generated by the AT90USB64/128 2-wire Serial Interface is (1/fSCL - 2/fCK), thus fCK must be greater than 6MHz for the low time requirement to be strictly met at fSCL = 100kHz. 7. The actual low period generated by the AT90USB64/128 2-wire Serial Interface is (1/fSCL - 2/fCK), thus the low time requirement will not be strictly met for fSCL > 308kHz when fCK = 8MHz. Still, AT90USB64/128 devices connected to the bus may communicate at full speed (400kHz) with other AT90USB64/128 devices, as well as any other device with a proper tLOW acceptance margin. Figure 31-3. 2-wire serial bus timing. tHD;STA Hold Time (repeated) START Condition fSCL ≤ 100kHz 4.0 – µs fSCL > 100kHz 0.6 – tLOW Low Period of the SCL Clock fSCL ≤ 100kHz (6) 4.7 – fSCL > 100kHz (7) 1.3 – tHIGH High period of the SCL clock fSCL ≤ 100kHz 4.0 – fSCL > 100kHz 0.6 – tSU;STA Set-up time for a repeated START condition fSCL ≤ 100kHz 4.7 – fSCL > 100kHz 0.6 – tHD;DAT Data hold time fSCL ≤ 100kHz 0 3.45 fSCL > 100kHz 0 0.9 tSU;DAT Data setup time fSCL ≤ 100kHz 250 – ns fSCL > 100kHz 100 – tSU;STO Setup time for STOP condition fSCL ≤ 100kHz 4.0 – µs fSCL > 100kHz 0.6 – tBUF Bus free time between a STOP and START condition fSCL ≤ 100kHz 4.7 – fSCL > 100kHz 1.3 – Table 31-2. 2-wire serial bus requirements. (Continued) Symbol Parameter Condition Min Max Units t SU;STA t LOW t HIGH t LOW t of t HD;STA t HD;DAT t SU;DAT t SU;STO t BUF SCL SDA t r395 7593L–AVR–09/12 AT90USB64/128 31.7 SPI timing characteristics See Figure 31-4 and Figure 31-5 on page 396 for details. Note: 1. In SPI Programming mode the minimum SCK high/low period is: - 2 tCLCL for fCK <12MHz - 3 tCLCL for fCK >12MHz Figure 31-4. SPI interface timing requirements (master mode). Table 31-3. SPI timing parameters. Description Mode Min. Typ. Max. 1 SCK period Master See Table 18-4 on page 174 ns 2 SCK high/low Master 50% duty cycle 3 Rise/Fall time Master 3.6 4 Setup Master 10 5 Hold Master 10 6 Out to SCK Master 0.5 × tsck 7 SCK to out Master 10 8 SCK to out high Master 10 9 SS low to out Slave 15 10 SCK period Slave 4 × tck 11 SCK high/low (1) Slave 2 × tck 12 Rise/Fall time Slave 1.6 µs 13 Setup Slave 10 ns 14 Hold Slave tck 15 SCK to out Slave 15 16 SCK to SS high Slave 20 17 SS high to tri-state Slave 10 18 SS low to SCK Slave 20 MOSI (Data output) SCK (CPOL = 1) MISO (Data input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 6 1 2 2 4 5 3 7 8396 7593L–AVR–09/12 AT90USB64/128 Figure 31-5. SPI interface timing requirements (slave mode). 31.8 Hardware boot entrance timing characteristics Figure 31-6. Hardware boot timing requirements. MISO (Data output) SCK (CPOL = 1) MOSI (Data input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 10 11 11 13 14 12 15 17 9 X 16 Table 31-4. Hardware boot timings. Symbol Parameter Min. Max. tSHRH HWB low Setup before Reset High 0 tHHRH HWB low Hold after Reset High StartUpTime (SUT) + Time Out Delay (TOUT) RESET ALE/HWB t SHRH t HHRH397 7593L–AVR–09/12 AT90USB64/128 31.9 ADC characteristics Table 31-5. ADC characteristics. Symbol Parameter Condition Min. Typ. Max. Units Resolution Single Ended Conversion 10 Bits Differential Conversion Gain = 1× or 10× 8 Differential Conversion Gain = 200× 7 Absolute accuracy (Including INL, DNL, quantization error, gain and offset error) Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 1.5 LSB Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 1MHz Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz Noise Reduction Mode 1.5 Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 1MHz Noise Reduction Mode Absolute accuracy Gain = 1×, 10×, 200× VREF = 4V, VCC = 5V ADC Clock = 50 - 200kHz 1 Integral Non-Linearity (INL) Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.5 1 Integral Non-Linearity (INL) (Accuracy after calibration for offset and gain error) Gain = 1×, 10×, 200× VREF = 4V, VCC = 5V ADC Clock = 50 - 200kHz 0.5 1 Differential Non-Linearity (DNL) Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.3 1 Gain Error Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz -2 0 +2 Gain = 1×, 10×, 200× -2 0 +2 Offset Error Single Ended Conversion VREF = 4V, VCC = 4V, ADC clock = 200kHz -2 1 +2 Gain = 1×, 10×, 200× VREF = 4V, VCC = 5V ADC Clock = 50 - 200kHz -1 0 +1 Conversion Time Free Running Conversion 65 260 µs Clock Frequency Single Ended Conversion 50 1000 kHz398 7593L–AVR–09/12 AT90USB64/128 AVCC Analog Supply Voltage VCC - 0.3 VCC + 0.3 V VREF Reference Voltage Single Ended Conversion 2.0 AVCC Differential Conversion 2.0 AVCC - 0.5 VIN Input Voltage Single ended channels 0 VREF Differential Conversion 0 AVCC Input Bandwidth Single Ended Channels 38,5 kHz Differential Channels 4 VINT1 Internal Voltage Reference 1.1V 1.0 1.1 1.2 V VINT2 Internal Voltage Reference 2.56V 2.4 2.56 2.8 RREF Reference Input Resistance 32 kΩ RAIN Analog Input Resistance 100 MΩ Table 31-5. ADC characteristics. (Continued) Symbol Parameter Condition Min. Typ. Max. Units399 7593L–AVR–09/12 AT90USB64/128 31.10 External data memory timing Notes: 1. This assumes 50% clock duty cycle. The half period is actually the high time of the external clock, XTAL1. 2. This assumes 50% clock duty cycle. The half period is actually the low time of the external clock, XTAL1. Table 31-6. External data memory characteristics, 4.5 - 5.5 Volts, no wait-state. Symbol Parameter 8MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 16 MHz 1 tLHLL ALE Pulse Width 115 1.0tCLCL-10 ns 2 tAVLL Address Valid A to ALE Low 57.5 0.5tCLCL-5 (1) 3a tLLAX_ST Address Hold After ALE Low, write access 5 5 3b tLLAX_LD Address Hold after ALE Low, read access 5 5 4 tAVLLC Address Valid C to ALE Low 57.5 0.5tCLCL-5 (1) 5 tAVRL Address Valid to RD Low 115 1.0tCLCL-10 6 tAVWL Address Valid to WR Low 115 1.0tCLCL-10 7 tLLWL ALE Low to WR Low 47.5 67.5 0.5tCLCL-15 (2) 0.5tCLCL+5 (2) 8 tLLRL ALE Low to RD Low 47.5 67.5 0.5tCLCL-15 (2) 0.5tCLCL+5 (2) 9 tDVRH Data Setup to RD High 40 40 10 tRLDV Read Low to Data Valid 75 1.0tCLCL-50 11 tRHDX Data Hold After RD High 0 0 12 tRLRH RD Pulse Width 115 1.0tCLCL-10 13 tDVWL Data Setup to WR Low 42.5 0.5tCLCL-20 (1) 14 tWHDX Data Hold After WR High 115 1.0tCLCL-10 15 tDVWH Data Valid to WR High 125 1.0tCLCL 16 tWLWH WR Pulse Width 115 1.0tCLCL-10 Table 31-7. External data memory characteristics, 4.5 - 5.5 Volts, 1 cycle wait-state. Symbol Parameter 8MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 16 MHz 10 tRLDV Read Low to Data Valid 200 2.0tCLCL-50 ns 12 tRLRH RD Pulse Width 240 2.0tCLCL-10 15 tDVWH Data Valid to WR High 240 2.0tCLCL 16 tWLWH WR Pulse Width 240 2.0tCLCL-10400 7593L–AVR–09/12 AT90USB64/128 Table 31-8. External data memory characteristics, 4.5 - 5.5 Volts, SRWn1 = 1, SRWn0 = 0. Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 16 MHz 10 tRLDV Read Low to Data Valid 325 3.0tCLCL-50 ns 12 tRLRH RD Pulse Width 365 3.0tCLCL-10 15 tDVWH Data Valid to WR High 375 3.0tCLCL 16 tWLWH WR Pulse Width 365 3.0tCLCL-10 Table 31-9. External data memory characteristics, 4.5 - 5.5 Volts, SRWn1 = 1, SRWn0 = 1. Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 16 MHz 10 tRLDV Read Low to Data Valid 325 3.0tCLCL-50 ns 12 tRLRH RD Pulse Width 365 3.0tCLCL-10 14 tWHDX Data Hold After WR High 240 2.0tCLCL-10 15 tDVWH Data Valid to WR High 375 3.0tCLCL 16 tWLWH WR Pulse Width 365 3.0tCLCL-10 Table 31-10. External data memory characteristics, 2.7 - 5.5 Volts, no wait-state. Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 8 MHz 1 tLHLL ALE Pulse Width 235 tCLCL-15 ns 2 tAVLL Address Valid A to ALE Low 115 0.5tCLCL-10 (1) 3a tLLAX_ST Address Hold After ALE Low, write access 5 5 3b tLLAX_LD Address Hold after ALE Low, read access 5 5 4 tAVLLC Address Valid C to ALE Low 115 0.5tCLCL-10 (1) 5 tAVRL Address Valid to RD Low 235 1.0tCLCL-15 6 tAVWL Address Valid to WR Low 235 1.0tCLCL-15 7 tLLWL ALE Low to WR Low 115 130 0.5tCLCL-10 (2) 0.5tCLCL+5 (2) 8 tLLRL ALE Low to RD Low 115 130 0.5tCLCL-10 (2) 0.5tCLCL+5 (2) 9 tDVRH Data Setup to RD High 45 45 10 tRLDV Read Low to Data Valid 190 1.0tCLCL-60 11 tRHDX Data Hold After RD High 0 0401 7593L–AVR–09/12 AT90USB64/128 Notes: 1. This assumes 50% clock duty cycle. The half period is actually the high time of the external clock, XTAL1. 2. This assumes 50% clock duty cycle. The half period is actually the low time of the external clock, XTAL1. 12 tRLRH RD Pulse Width 235 1.0tCLCL-15 ns 13 tDVWL Data Setup to WR Low 105 0.5tCLCL-20 (1) 14 tWHDX Data Hold After WR High 235 1.0tCLCL-15 15 tDVWH Data Valid to WR High 250 1.0tCLCL 16 tWLWH WR Pulse Width 235 1.0tCLCL-15 Table 31-10. External data memory characteristics, 2.7 - 5.5 Volts, no wait-state. (Continued) Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit Table 31-11. External data memory characteristics, 2.7 - 5.5 Volts, SRWn1 = 0, SRWn0 = 1. Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 8 MHz 10 tRLDV Read Low to Data Valid 440 2.0tCLCL-60 ns 12 tRLRH RD Pulse Width 485 2.0tCLCL-15 15 tDVWH Data Valid to WR High 500 2.0tCLCL 16 tWLWH WR Pulse Width 485 2.0tCLCL-15 Table 31-12. External data memory characteristics, 2.7 - 5.5 Volts, SRWn1 = 1, SRWn0 = 0. Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 8 MHz 10 tRLDV Read Low to Data Valid 690 3.0tCLCL-60 ns 12 tRLRH RD Pulse Width 735 3.0tCLCL-15 15 tDVWH Data Valid to WR High 750 3.0tCLCL 16 tWLWH WR Pulse Width 735 3.0tCLCL-15 Table 31-13. External data memory characteristics, 2.7 - 5.5 Volts, SRWn1 = 1, SRWn0 = 1. Symbol Parameter 4MHz oscillator Variable oscillator Min. Max. Min. Max. Unit 0 1/tCLCL Oscillator Frequency 0.0 8 MHz 10 tRLDV Read Low to Data Valid 690 3.0tCLCL-60 ns 12 tRLRH RD Pulse Width 735 3.0tCLCL-15 14 tWHDX Data Hold After WR High 485 2.0tCLCL-15 15 tDVWH Data Valid to WR High 750 3.0tCLCL 16 tWLWH WR Pulse Width 735 3.0tCLCL-15402 7593L–AVR–09/12 AT90USB64/128 Figure 31-7. External memory timing (SRWn1 = 0, SRWn0 = 0. Figure 31-8. External memory timing (SRWn1 = 0, SRWn0 = 1). ALE T1 T2 T3 Write Read WR T4 A15:8 Prev. addr. Address DA7:0 Prev. data Address XX Data RD DA7:0 (XMBK = 0) Address Data System clock (CLK CPU) 1 4 2 7 6 3a 3b 5 8 12 16 13 10 11 14 15 9 ALE T1 T2 T3 Write Read WR T5 A15:8 Prev. addr. Address DA7:0 Prev. data Address XX Data RD DA7:0 (XMBK = 0) Address Data System clock (CLK CPU) 1 4 2 7 6 3a 3b 5 8 12 16 13 10 11 14 15 9 T4403 7593L–AVR–09/12 AT90USB64/128 Figure 31-9. External memory timing (SRWn1 = 1, SRWn0 = 0). Figure 31-10. External memory timing (SRWn1 = 1, SRWn0 = 1). The ALE pulse in the last period (T4-T7) is only present if the next instruction accesses the RAM (internal or external). ALE T1 T2 T3 Write Read WR T6 A15:8 Prev. addr. Address DA7:0 Prev. data Address XX Data RD DA7:0 (XMBK = 0) Address Data System clock (CLK CPU) 1 4 2 7 6 3a 3b 5 8 12 16 13 10 11 14 15 9 T4 T5 ALE T1 T2 T3 Write Read WR T7 A15:8 Prev. addr. Address DA7:0 Prev. data Address XX Data RD DA7:0 (XMBK = 0) Address Data System clock (CLK CPU) 1 4 2 7 6 3a 3b 5 8 12 16 13 10 11 14 15 9 T4 T5 T6404 7593L–AVR–09/12 AT90USB64/128 32. Atmel AT90USB64/128 typical characteristics The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A sine wave generator with rail-to-rail output is used as clock source. All Active- and Idle current consumption measurements are done with all bits in the PRR registers set and thus, the corresponding I/O modules are turned off. Also the Analog Comparator is disabled during these measurements. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as CL×VCC×f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer.405 7593L–AVR–09/12 AT90USB64/128 32.1 Input voltage levels Figure 32-1. Input low voltage vs. VCC, all I/Os excluding DP/DM, XTAL1 and reset. Figure 32-2. Input high voltage vs. VCC, all I/Os excluding DP/DM, XTAL1 and reset. 0.50 0.75 1.00 1.25 1.50 1.75 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) Thres hold (V) 85 25 -40 0.50 0.75 1.00 1.25 1.50 1.75 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) Thres hold (V) 85 25 -40406 7593L–AVR–09/12 AT90USB64/128 32.2 Output voltage levels Figure 32-3. Output low voltage vs. output current, all I/Os excluding DP/DM, VCC = 3V. Figure 32-4. Output low voltage vs. output current, all I/Os excluding DP/DM, VCC = 5V. 0 0.2 0.4 0.6 0.8 1.0 1.2 0 5 10 15 20 I OL (mA) VOL (V) 85 25 -40 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 5 10 15 20 I OL (mA) VOL (V) 85 25 -40407 7593L–AVR–09/12 AT90USB64/128 Figure 32-5. Output high voltage vs. output current, all I/Os excluding DP/DM, VCC = 3V. Figure 32-6. Output high voltage vs. output current, all I/Os excluding DP/DM, VCC = 5V. 1.8 2.0 2.2 2.4 2.6 2.8 3.0 0 5 10 15 20 I OH (mA) VOH (V) 85 25 -40 4.2 4.4 4.6 4.8 5.0 0 5 10 15 20 I OH (mA) VOH (V) 85 25 -40408 7593L–AVR–09/12 AT90USB64/128 32.3 Power-down supply current Figure 32-7. Power-down supply current vs. VCC, with BOD disabled, WDT disabled, T = 25°C. Figure 32-8. Power-down supply current vs. VCC, with BOD disabled, WDT enabled, T = 25°C. 0 0.5 1.0 1.5 2.0 2.5 3.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) ICC (µA) 0 2 4 6 8 10 12 14 16 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) ICC (µA)409 7593L–AVR–09/12 AT90USB64/128 Figure 32-9. Power-down supply current vs. VCC, with BOD enabled, WDT enabled, T = 25°C. 32.4 Power-save supply current Figure 32-10. Power-save supply current vs. VCC, with BOD & WDT disabled, T = 25°C. 0 10 20 30 40 50 60 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) ICC (µA) 0 1 2 3 4 5 6 7 8 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) ICC (µA)410 7593L–AVR–09/12 AT90USB64/128 32.5 Idle supply current Figure 32-11. Idle supply current vs. frequency, T = 25°C. 32.6 Active supply current Figure 32-12. Active supply current vs. frequency, T = 25°C. 0 5 10 15 20 246 8 10 12 14 16 Frequency (MHz) ICC (mA) 5.5 5.0 4.5 3.3 2.7 0 5 10 15 20 25 246 8 10 12 14 16 Frequency (MHz) ICC (mA) 5.5 5.0 4.5 3.3 2.7411 7593L–AVR–09/12 AT90USB64/128 32.7 Reset supply current Figure 32-13. Reset supply current vs. frequency. 32.8 I/O pull-up current Figure 32-14. I/O pull-up current vs. pin voltage, VCC = 5V. 0 2 4 6 8 10 12 4 6 8 10 12 14 16 Frequency (MHz) ICC (mA) 5.5 5.0 4.5 3.3 2.7 -20 0 20 40 60 80 100 120 140 012345 VOP (V) IOP (uA) 85 25 -40412 7593L–AVR–09/12 AT90USB64/128 Figure 32-15. Reset pull-up current vs. pin voltage, VCC = 5V. 32.9 Bandgap voltage Figure 32-16. Bandgap voltage vs. temperature. 0 20 40 60 80 100 120 012345 VRESET (V) IRESET (µA) 85 25 -40 1.080 1.085 1.090 1.095 1.100 1.105 1.110 1.115 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) Bandgap voltage (V) 5.5 5.0 4.5 4.0 3.6 2.7413 7593L–AVR–09/12 AT90USB64/128 32.10 Internal ARef voltage Figure 32-17. Internal ARef reference voltage vs. temperature, VCC = 2.7-5.5V. 32.11 USB regulator Figure 32-18. USB regulator quiescent current vs. input voltage, no load. 2.54 2.56 2.58 2.60 2.62 2.64 -40 -20 0 20 40 60 80 Temperature (°C) Tens ion Vref Inter (V) 0 10 20 30 40 50 60 70 80 90 100 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Voltage (V) ICC (µA)414 7593L–AVR–09/12 AT90USB64/128 Figure 32-19. USB regulator output voltage vs. input voltage, load = 75Ω. Note: The 75Ω load is equivalent to the maximum average consumption of the USB peripheral in operation (full bus load). 32.12 BOD levels Figure 32-20. BOD voltage (2.4V level) vs. temperature. 2.6 2.8 3.0 3.2 3.4 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) Output voltage (V) 85 25 -40 2.42 2.44 2.46 2.48 2.50 2.52 2.54 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) Thres hold (V) Rising Vcc Falling Vcc415 7593L–AVR–09/12 AT90USB64/128 Figure 32-21. BOD voltage (3.4V level) vs. temperature. Figure 32-22. BOD voltage (4.3V level) vs. temperature. 3.42 3.44 3.46 3.48 3.50 3.52 3.54 3.56 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) Thres hold (V) Rising Vcc Falling Vcc 4.34 4.36 4.38 4.40 4.42 4.44 4.46 4.48 4.50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) Thres hold (V) Rising Vcc Falling Vcc416 7593L–AVR–09/12 AT90USB64/128 32.13 Watchdog timer frequency Figure 32-23. WDT oscillator frequency vs. VCC. 32.14 Internal RC oscillator frequency Figure 32-24. RC oscillator frequency vs. OSCCAL, T = 25°C. 108 110 112 114 116 118 120 122 124 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) FRC (kHz) 85 25 -40 2 4 6 8 10 12 14 16 -1 15 31 47 63 79 95 111 127 143 159 175 191 207 223 239 255 OSCCAL (X1) FRC (MHz)417 7593L–AVR–09/12 AT90USB64/128 Figure 32-25. RC oscillator frequency vs. VCC. Figure 32-26. RC oscillator frequency vs. temperature. 7.8 7.9 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VCC (V) FRC (MHz) 85 25 -40 7.8 8.0 8.2 8.4 8.6 8.8 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) FRC (MHz) 5.5 4.0 3.3 3.0 2.7418 7593L–AVR–09/12 AT90USB64/128 32.15 Power-on reset Figure 32-27. Power-on reset level vs. temperature. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) POR Voltage (V)419 7593L–AVR–09/12 AT90USB64/128 33. Register summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page (0xFF) Reserved - - - - - - - - (0xFE) Reserved - - - - - - - - (0xFD) Reserved - - - - - - - - (0xFC) Reserved - - - - - - - - (0xFB) Reserved - - - - - - - - (0xFA) Reserved - - - - - - - - (0xF9) OTGTCON PAGE VALUE (0xF8) UPINT PINT7:0 (0xF7) UPBCHX - - - - - PBYCT10:8 (0xF6) UPBCLX PBYCT7:0 (0xF5) UPERRX - COUNTER1:0 CRC16 TIMEOUT PID DATAPID DATATGL (0xF4) UEINT EPINT6:0 (0xF3) UEBCHX - - - - - BYCT10:8 (0xF2) UEBCLX BYCT7:0 (0xF1) UEDATX DAT7:0 (0xF0) UEIENX FLERRE NAKINE - NAKOUTE RXSTPE RXOUTE STALLEDE TXINE (0xEF) UESTA1X - - - - - CTRLDIR CURRBK1:0 (0xEE) UESTA0X CFGOK OVERFI UNDERFI - DTSEQ1:0 NBUSYBK1:0 (0xED) UECFG1X EPSIZE2:0 EPBK1:0 ALLOC (0xEC) UECFG0X EPTYPE1:0 - - EPDIR (0xEB) UECONX STALLRQ STALLRQC RSTDT EPEN (0xEA) UERST EPRST6:0 (0xE9) UENUM EPNUM2:0 (0xE8) UEINTX FIFOCON NAKINI RWAL NAKOUTI RXSTPI RXOUTI STALLEDI TXINI (0xE7) Reserved - - - - (0xE6) UDMFN FNCERR (0xE5) UDFNUMH FNUM10:8 (0xE4) UDFNUML FNUM7:0 (0xE3) UDADDR ADDEN UADD6:0 (0xE2) UDIEN UPRSME EORSME WAKEUPE EORSTE SOFE SUSPE (0xE1) UDINT UPRSMI EORSMI WAKEUPI EORSTI SOFI SUSPI (0xE0) UDCON LSM RMWKUP DETACH (0xDF) OTGINT STOI HNPERRI ROLEEXI BCERRI VBERRI SRPI (0xDE) OTGIEN STOE HNPERRE ROLEEXE BCERRE VBERRE SRPE (0xDD) OTGCON HNPREQ SRPREQ SRPSEL VBUSHWC VBUSREQ VBUSRQC (0xDC) Reserved (0xDB) Reserved (0xDA) USBINT IDTI VBUSTI (0xD9) USBSTA SPEED ID VBUS (0xD8) USBCON USBE HOST FRZCLK OTGPADE IDTE VBUSTE (0xD7) UHWCON UIMOD UIDE UVCONE UVREGE (0xD6) Reserved (0xD5) Reserved (0xD4) Reserved (0xD3) Reserved (0xD2) Reserved - - - - - - - - (0xD1) Reserved - - - - - - - - (0xD0) Reserved - - - - - - - - (0xCF) Reserved - - - - - - - - (0xCE) UDR1 USART1 I/O Data Register (0xCD) UBRR1H - - - - USART1 Baud Rate Register High Byte (0xCC) UBRR1L USART1 Baud Rate Register Low Byte (0xCB) Reserved - - - - - - - - (0xCA) UCSR1C UMSEL11 UMSEL10 UPM11 UPM10 USBS1 UCSZ11 UCSZ10 UCPOL1 (0xC9) UCSR1B RXCIE1 TXCIE1 UDRIE1 RXEN1 TXEN1 UCSZ12 RXB81 TXB81 (0xC8) UCSR1A RXC1 TXC1 UDRE1 FE1 DOR1 PE1 U2X1 MPCM1 (0xC7) Reserved - - - - - - - - (0xC6) Reserved - - - - - - - - (0xC5) Reserved - - - - - - - - (0xC4) Reserved - - - - - - - - (0xC3) Reserved - - - - - - - - (0xC2) Reserved - - - - - - - - (0xC1) Reserved - - - - - - - - (0xC0) Reserved - - - - - - - - (0xBF) Reserved - - - - - - - -420 7593L–AVR–09/12 AT90USB64/128 (0xBE) Reserved - - - - - - - - (0xBD) TWAMR TWAM6 TWAM5 TWAM4 TWAM3 TWAM2 TWAM1 TWAM0 - (0xBC) TWCR TWINT TWEA TWSTA TWSTO TWWC TWEN - TWIE (0xBB) TWDR 2-wire Serial Interface Data Register (0xBA) TWAR TWA6 TWA5 TWA4 TWA3 TWA2 TWA1 TWA0 TWGCE (0xB9) TWSR TWS7 TWS6 TWS5 TWS4 TWS3 - TWPS1 TWPS0 (0xB8) TWBR 2-wire Serial Interface Bit Rate Register (0xB7) Reserved - - - - - - - - (0xB6) ASSR - EXCLK AS2 TCN2UB OCR2AUB OCR2BUB TCR2AUB TCR2BUB (0xB5) Reserved - - - - - - - - (0xB4) OCR2B Timer/Counter2 Output Compare Register B (0xB3) OCR2A Timer/Counter2 Output Compare Register A (0xB2) TCNT2 Timer/Counter2 (8 Bit) (0xB1) TCCR2B FOC2A FOC2B - - WGM22 CS22 CS21 CS20 (0xB0) TCCR2A COM2A1 COM2A0 COM2B1 COM2B0 - - WGM21 WGM20 (0xAF) UPDATX PDAT7:0 (0xAE) UPIENX FLERRE NAKEDE - PERRE TXSTPE TXOUTE RXSTALLE RXINE (0xAD) UPCFG2X INTFRQ7:0 (0xAC) UPSTAX CFGOK OVERFI UNDERFI DTSEQ1:0 NBUSYBK1:0 (0xAB) UPCFG1X PSIZE2:0 PBK1:0 ALLOC (0xAA) UPCFG0X PTYPE1:0 PTOKEN1:0 PEPNUM3:0 (0xA9) UPCONX PFREEZE INMODE RSTDT PEN (0xA8) UPRST PRST6:0 (0xA7) UPNUM PNUM2:0 (0xA6) UPINTX FIFOCON NAKEDI RWAL PERRI TXSTPI TXOUTI RXSTALLI RXINI (0xA5) UPINRQX INRQ7:0 (0xA4) UHFLEN FLEN7:0 (0xA3) UHFNUMH FNUM10:8 (0xA2) UHFNUML FNUM7:0 (0xA1) UHADDR HADD6:0 (0xA0) UHIEN HWUPE HSOFE RXRSME RSMEDE RSTE DDISCE DCONNE (0x9F) UHINT HWUPI HSOFI RXRSMI RSMEDI RSTI DDISCI DCONNI (0x9E) UHCON RESUME RESET SOFEN (0x9D) OCR3CH Timer/Counter3 - Output Compare Register C High Byte (0x9C) OCR3CL Timer/Counter3 - Output Compare Register C Low Byte (0x9B) OCR3BH Timer/Counter3 - Output Compare Register B High Byte (0x9A) OCR3BL Timer/Counter3 - Output Compare Register B Low Byte (0x99) OCR3AH Timer/Counter3 - Output Compare Register A High Byte (0x98) OCR3AL Timer/Counter3 - Output Compare Register A Low Byte (0x97) ICR3H Timer/Counter3 - Input Capture Register High Byte (0x96) ICR3L Timer/Counter3 - Input Capture Register Low Byte (0x95) TCNT3H Timer/Counter3 - Counter Register High Byte (0x94) TCNT3L Timer/Counter3 - Counter Register Low Byte (0x93) Reserved - - - - - - - - (0x92) TCCR3C FOC3A FOC3B FOC3C - - - - - (0x91) TCCR3B ICNC3 ICES3 - WGM33 WGM32 CS32 CS31 CS30 (0x90) TCCR3A COM3A1 COM3A0 COM3B1 COM3B0 COM3C1 COM3C0 WGM31 WGM30 (0x8F) Reserved - - - - - - - - (0x8E) Reserved - - - - - - - - (0x8D) OCR1CH Timer/Counter1 - Output Compare Register C High Byte (0x8C) OCR1CL Timer/Counter1 - Output Compare Register C Low Byte (0x8B) OCR1BH Timer/Counter1 - Output Compare Register B High Byte (0x8A) OCR1BL Timer/Counter1 - Output Compare Register B Low Byte (0x89) OCR1AH Timer/Counter1 - Output Compare Register A High Byte (0x88) OCR1AL Timer/Counter1 - Output Compare Register A Low Byte (0x87) ICR1H Timer/Counter1 - Input Capture Register High Byte (0x86) ICR1L Timer/Counter1 - Input Capture Register Low Byte (0x85) TCNT1H Timer/Counter1 - Counter Register High Byte (0x84) TCNT1L Timer/Counter1 - Counter Register Low Byte (0x83) Reserved - - - - - - - - (0x82) TCCR1C FOC1A FOC1B FOC1C - - - - - (0x81) TCCR1B ICNC1 ICES1 - WGM13 WGM12 CS12 CS11 CS10 (0x80) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 COM1C1 COM1C0 WGM11 WGM10 (0x7F) DIDR1 - - - - - - AIN1D AIN0D (0x7E) DIDR0 ADC7D ADC6D ADC5D ADC4D ADC3D ADC2D ADC1D ADC0D (0x7D) - - - - - - - - - Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page421 7593L–AVR–09/12 AT90USB64/128 (0x7C) ADMUX REFS1 REFS0 ADLAR MUX4 MUX3 MUX2 MUX1 MUX0 (0x7B) ADCSRB ADHSM ACME - - - ADTS2 ADTS1 ADTS0 (0x7A) ADCSRA ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 (0x79) ADCH ADC Data Register High byte (0x78) ADCL ADC Data Register Low byte (0x77) Reserved - - - - - - - - (0x76) Reserved - - - - - - - - (0x75) XMCRB XMBK - - - - XMM2 XMM1 XMM0 (0x74) XMCRA SRE SRL2 SRL1 SRL0 SRW11 SRW10 SRW01 SRW00 (0x73) Reserved - - - - - - - - (0x72) Reserved - - - - - - - - (0x71) TIMSK3 - - ICIE3 - OCIE3C OCIE3B OCIE3A TOIE3 (0x70) TIMSK2 - - - - - OCIE2B OCIE2A TOIE2 (0x6F) TIMSK1 - - ICIE1 - OCIE1C OCIE1B OCIE1A TOIE1 (0x6E) TIMSK0 - - - - - OCIE0B OCIE0A TOIE0 (0x6D) Reserved - - - - - - - - (0x6C) Reserved - - - - - - - - (0x6B) PCMSK0 PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 (0x6A) EICRB ISC71 ISC70 ISC61 ISC60 ISC51 ISC50 ISC41 ISC40 (0x69) EICRA ISC31 ISC30 ISC21 ISC20 ISC11 ISC10 ISC01 ISC00 (0x68) PCICR - - - - - - - PCIE0 (0x67) Reserved - - - - - - - - (0x66) OSCCAL Oscillator Calibration Register (0x65) PRR1 PRUSB - - - PRTIM3 - - PRUSART1 (0x64) PRR0 PRTWI PRTIM2 PRTIM0 - PRTIM1 PRSPI - PRADC (0x63) Reserved - - - - - - - - (0x62) Reserved - - - - - - - - (0x61) CLKPR CLKPCE - - - CLKPS3 CLKPS2 CLKPS1 CLKPS0 (0x60) WDTCSR WDIF WDIE WDP3 WDCE WDE WDP2 WDP1 WDP0 0x3F (0x5F) SREG I T H S V N Z C 0x3E (0x5E) SPH SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 0x3C (0x5C) Reserved - - - - - - - - 0x3B (0x5B) RAMPZ - - - - - - RAMPZ1 RAMPZ0 0x3A (0x5A) Reserved - - - - - - - - 0x39 (0x59) Reserved - - - - - - - - 0x38 (0x58) Reserved - - - - - - - - 0x37 (0x57) SPMCSR SPMIE RWWSB SIGRD RWWSRE BLBSET PGWRT PGERS SPMEN 0x36 (0x56) Reserved - - - - - - - - 0x35 (0x55) MCUCR JTD - - PUD - - IVSEL IVCE 0x34 (0x54) MCUSR - - - JTRF WDRF BORF EXTRF PORF 0x33 (0x53) SMCR - - - - SM2 SM1 SM0 SE 0x32 (0x52) Reserved - - - - - - - - 0x31 (0x51) OCDR/ MONDR OCDR7 OCDR6 OCDR5 OCDR4 OCDR3 OCDR2 OCDR1 OCDR0 Monitor Data Register 0x30 (0x50) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 0x2F (0x4F) Reserved - - - - - - - - 0x2E (0x4E) SPDR SPI Data Register 0x2D (0x4D) SPSR SPIF WCOL - - - - - SPI2X 0x2C (0x4C) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 0x2B (0x4B) GPIOR2 General Purpose I/O Register 2 0x2A (0x4A) GPIOR1 General Purpose I/O Register 1 0x29 (0x49) PLLCSR - - - PLLP2 PLLP1 PLLP0 PLLE PLOCK 0x28 (0x48) OCR0B Timer/Counter0 Output Compare Register B 0x27 (0x47) OCR0A Timer/Counter0 Output Compare Register A 0x26 (0x46) TCNT0 Timer/Counter0 (8 Bit) 0x25 (0x45) TCCR0B FOC0A FOC0B - - WGM02 CS02 CS01 CS00 0x24 (0x44) TCCR0A COM0A1 COM0A0 COM0B1 COM0B0 - - WGM01 WGM00 0x23 (0x43) GTCCR TSM - - - - - PSRASY PSRSYNC 0x22 (0x42) EEARH - - - - EEPROM Address Register High Byte 0x21 (0x41) EEARL EEPROM Address Register Low Byte 0x20 (0x40) EEDR EEPROM Data Register 0x1F (0x3F) EECR - - EEPM1 EEPM0 EERIE EEMPE EEPE EERE 0x1E (0x3E) GPIOR0 General Purpose I/O Register 0 0x1D (0x3D) EIMSK INT7 INT6 INT5 INT4 INT3 INT2 INT1 INT0 0x1C (0x3C) EIFR INTF7 INTF6 INTF5 INTF4 INTF3 INTF2 INTF1 INTF0 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page422 7593L–AVR–09/12 AT90USB64/128 Note: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 2. I/O registers within the address range $00 - $1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the status flags are cleared by writing a logical one to them. Note that the CBI and SBI instructions will operate on all bits in the I/O register, writing a one back into any flag read as set, thus clearing the flag. The CBI and SBI instructions work with registers 0x00 to 0x1F only. 4. When using the I/O specific commands IN and OUT, the I/O addresses $00 - $3F must be used. When addressing I/O registers as data space using LD and ST instructions, $20 must be added to these addresses. The Atmel AT90USB64/128 is a complex microcontroller with more peripheral units than can be supported within the 64 location reserved in Opcode for the IN and OUT instructions. For the Extended I/O space from $60 - $1FF in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used. 0x1B (0x3B) PCIFR - - - - - - - PCIF0 0x1A (0x3A) Reserved - - - - - - - - 0x19 (0x39) Reserved - - - - - - - - 0x18 (0x38) TIFR3 - - ICF3 - OCF3C OCF3B OCF3A TOV3 0x17 (0x37) TIFR2 - - - - - OCF2B OCF2A TOV2 0x16 (0x36) TIFR1 - - ICF1 - OCF1C OCF1B OCF1A TOV1 0x15 (0x35) TIFR0 - - - - - OCF0B OCF0A TOV0 0x14 (0x34) Reserved - - - - - - - - 0x13 (0x33) Reserved - - - - - - - - 0x12 (0x32) Reserved - - - - - - - - 0x11 (0x31) PORTF PORTF7 PORTF6 PORTF5 PORTF4 PORTF3 PORTF2 PORTF1 PORTF0 0x10 (0x30) DDRF DDF7 DDF6 DDF5 DDF4 DDF3 DDF2 DDF1 DDF0 0x0F (0x2F) PINF PINF7 PINF6 PINF5 PINF4 PINF3 PINF2 PINF1 PINF0 0x0E (0x2E) PORTE PORTE7 PORTE6 PORTE5 PORTE4 PORTE3 PORTE2 PORTE1 PORTE0 0x0D (0x2D) DDRE DDE7 DDE6 DDE5 DDE4 DDE3 DDE2 DDE1 DDE0 0x0C (0x2C) PINE PINE7 PINE6 PINE5 PINE4 PINE3 PINE2 PINE1 PINE0 0x0B (0x2B) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 0x0A (0x2A) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 0x09 (0x29) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 0x08 (0x28) PORTC PORTC7 PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 0x07 (0x27) DDRC DDC7 DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 0x06 (0x26) PINC PINC7 PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 0x05 (0x25) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 0x04 (0x24) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 0x03 (0x23) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 0x02 (0x22) PORTA PORTA7 PORTA6 PORTA5 PORTA4 PORTA3 PORTA2 PORTA1 PORTA0 0x01 (0x21) DDRA DDA7 DDA6 DDA5 DDA4 DDA3 DDA2 DDA1 DDA0 0x00 (0x20) PINA PINA7 PINA6 PINA5 PINA4 PINA3 PINA2 PINA1 PINA0 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page423 7593L–AVR–09/12 AT90USB64/128 34. Instruction set summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers Rd ← Rd + Rr Z,C,N,V,H 1 ADC Rd, Rr Add with Carry two Registers Rd ← Rd + Rr + C Z,C,N,V,H 1 ADIW Rdl,K Add Immediate to Word Rdh:Rdl ← Rdh:Rdl + K Z,C,N,V,S 2 SUB Rd, Rr Subtract two Registers Rd ← Rd - Rr Z,C,N,V,H 1 SUBI Rd, K Subtract Constant from Register Rd ← Rd - K Z,C,N,V,H 1 SBC Rd, Rr Subtract with Carry two Registers Rd ← Rd - Rr - C Z,C,N,V,H 1 SBCI Rd, K Subtract with Carry Constant from Reg. Rd ← Rd - K - C Z,C,N,V,H 1 SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl ← Rdh:Rdl - K Z,C,N,V,S 2 AND Rd, Rr Logical AND Registers Rd ← Rd • Rr Z,N,V 1 ANDI Rd, K Logical AND Register and Constant Rd ← Rd • K Z,N,V 1 OR Rd, Rr Logical OR Registers Rd ← Rd v Rr Z,N,V 1 ORI Rd, K Logical OR Register and Constant Rd ← Rd v K Z,N,V 1 EOR Rd, Rr Exclusive OR Registers Rd ← Rd ⊕ Rr Z,N,V 1 COM Rd One’s Complement Rd ← 0xFF − Rd Z,C,N,V 1 NEG Rd Two’s Complement Rd ← 0x00 − Rd Z,C,N,V,H 1 SBR Rd,K Set Bit(s) in Register Rd ← Rd v K Z,N,V 1 CBR Rd,K Clear Bit(s) in Register Rd ← Rd • (0xFF - K) Z,N,V 1 INC Rd Increment Rd ← Rd + 1 Z,N,V 1 DEC Rd Decrement Rd ← Rd − 1 Z,N,V 1 TST Rd Test for Zero or Minus Rd ← Rd • Rd Z,N,V 1 CLR Rd Clear Register Rd ← Rd ⊕ Rd Z,N,V 1 SER Rd Set Register Rd ← 0xFF None 1 MUL Rd, Rr Multiply Unsigned R1:R0 ← Rd x Rr Z,C 2 MULS Rd, Rr Multiply Signed R1:R0 ← Rd x Rr Z,C 2 MULSU Rd, Rr Multiply Signed with Unsigned R1:R0 ← Rd x Rr Z,C 2 FMUL Rd, Rr Fractional Multiply Unsigned R1:R0 ← (Rd x Rr) << 1 Z,C 2 FMULS Rd, Rr Fractional Multiply Signed R1:R0 ← (Rd x Rr) << 1 Z,C 2 FMULSU Rd, Rr Fractional Multiply Signed with Unsigned R1:R0 ← (Rd x Rr) << 1 Z,C 2 BRANCH INSTRUCTIONS RJMP k Relative Jump PC ← PC + k + 1 None 2 IJMP Indirect Jump to (Z) PC ← Z None 2 EIJMP Extended Indirect Jump to (Z) PC ←(EIND:Z) None 2 JMP k Direct Jump PC ← k None 3 RCALL k Relative Subroutine Call PC ← PC + k + 1 None 4 ICALL Indirect Call to (Z) PC ← Z None 4 EICALL Extended Indirect Call to (Z) PC ←(EIND:Z) None 4 CALL k Direct Subroutine Call PC ← k None 5 RET Subroutine Return PC ← STACK None 5 RETI Interrupt Return PC ← STACK I 5 CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC ← PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd − Rr Z, N,V,C,H 1 CPC Rd,Rr Compare with Carry Rd − Rr − C Z, N,V,C,H 1 CPI Rd,K Compare Register with Immediate Rd − K Z, N,V,C,H 1 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC ← PC + 2 or 3 None 1/2/3 SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC ← PC + 2 or 3 None 1/2/3 BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PC←PC+k + 1 None 1/2 BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PC←PC+k + 1 None 1/2 BREQ k Branch if Equal if (Z = 1) then PC ← PC + k + 1 None 1/2 BRNE k Branch if Not Equal if (Z = 0) then PC ← PC + k + 1 None 1/2 BRCS k Branch if Carry Set if (C = 1) then PC ← PC + k + 1 None 1/2 BRCC k Branch if Carry Cleared if (C = 0) then PC ← PC + k + 1 None 1/2 BRSH k Branch if Same or Higher if (C = 0) then PC ← PC + k + 1 None 1/2 BRLO k Branch if Lower if (C = 1) then PC ← PC + k + 1 None 1/2 BRMI k Branch if Minus if (N = 1) then PC ← PC + k + 1 None 1/2 BRPL k Branch if Plus if (N = 0) then PC ← PC + k + 1 None 1/2 BRGE k Branch if Greater or Equal, Signed if (N ⊕ V= 0) then PC ← PC + k + 1 None 1/2 BRLT k Branch if Less Than Zero, Signed if (N ⊕ V= 1) then PC ← PC + k + 1 None 1/2 BRHS k Branch if Half Carry Flag Set if (H = 1) then PC ← PC + k + 1 None 1/2 BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC ← PC + k + 1 None 1/2 BRTS k Branch if T Flag Set if (T = 1) then PC ← PC + k + 1 None 1/2 BRTC k Branch if T Flag Cleared if (T = 0) then PC ← PC + k + 1 None 1/2 BRVS k Branch if Overflow Flag is Set if (V = 1) then PC ← PC + k + 1 None 1/2424 7593L–AVR–09/12 AT90USB64/128 BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC ← PC + k + 1 None 1/2 BRIE k Branch if Interrupt Enabled if ( I = 1) then PC ← PC + k + 1 None 1/2 BRID k Branch if Interrupt Disabled if ( I = 0) then PC ← PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set Bit in I/O Register I/O(P,b) ← 1 None 2 CBI P,b Clear Bit in I/O Register I/O(P,b) ← 0 None 2 LSL Rd Logical Shift Left Rd(n+1) ← Rd(n), Rd(0) ← 0 Z,C,N,V 1 LSR Rd Logical Shift Right Rd(n) ← Rd(n+1), Rd(7) ← 0 Z,C,N,V 1 ROL Rd Rotate Left Through Carry Rd(0)←C,Rd(n+1)← Rd(n),C←Rd(7) Z,C,N,V 1 ROR Rd Rotate Right Through Carry Rd(7)←C,Rd(n)← Rd(n+1),C←Rd(0) Z,C,N,V 1 ASR Rd Arithmetic Shift Right Rd(n) ← Rd(n+1), n=0..6 Z,C,N,V 1 SWAP Rd Swap Nibbles Rd(3..0)←Rd(7..4),Rd(7..4)←Rd(3..0) None 1 BSET s Flag Set SREG(s) ← 1 SREG(s) 1 BCLR s Flag Clear SREG(s) ← 0 SREG(s) 1 BST Rr, b Bit Store from Register to T T ← Rr(b) T 1 BLD Rd, b Bit load from T to Register Rd(b) ← T None 1 SEC Set Carry C ← 1 C1 CLC Clear Carry C ← 0 C 1 SEN Set Negative Flag N ← 1 N1 CLN Clear Negative Flag N ← 0 N 1 SEZ Set Zero Flag Z ← 1 Z1 CLZ Clear Zero Flag Z ← 0 Z 1 SEI Global Interrupt Enable I ← 1 I1 CLI Global Interrupt Disable I ← 0 I 1 SES Set Signed Test Flag S ← 1 S1 CLS Clear Signed Test Flag S ← 0 S 1 SEV Set Twos Complement Overflow. V ← 1 V1 CLV Clear Twos Complement Overflow V ← 0 V 1 SET Set T in SREG T ← 1 T1 CLT Clear T in SREG T ← 0 T 1 SEH Set Half Carry Flag in SREG H ← 1 H1 CLH Clear Half Carry Flag in SREG H ← 0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers Rd ← Rr None 1 MOVW Rd, Rr Copy Register Word Rd+1:Rd ← Rr+1:Rr None 1 LDI Rd, K Load Immediate Rd ← K None 1 LD Rd, X Load Indirect Rd ← (X) None 2 LD Rd, X+ Load Indirect and Post-Inc. Rd ← (X), X ← X + 1 None 2 LD Rd, - X Load Indirect and Pre-Dec. X ← X - 1, Rd ← (X) None 2 LD Rd, Y Load Indirect Rd ← (Y) None 2 LD Rd, Y+ Load Indirect and Post-Inc. Rd ← (Y), Y ← Y + 1 None 2 LD Rd, - Y Load Indirect and Pre-Dec. Y ← Y - 1, Rd ← (Y) None 2 LDD Rd,Y+q Load Indirect with Displacement Rd ← (Y + q) None 2 LD Rd, Z Load Indirect Rd ← (Z) None 2 LD Rd, Z+ Load Indirect and Post-Inc. Rd ← (Z), Z ← Z+1 None 2 LD Rd, -Z Load Indirect and Pre-Dec. Z ← Z - 1, Rd ← (Z) None 2 LDD Rd, Z+q Load Indirect with Displacement Rd ← (Z + q) None 2 LDS Rd, k Load Direct from SRAM Rd ← (k) None 2 ST X, Rr Store Indirect (X) ← Rr None 2 ST X+, Rr Store Indirect and Post-Inc. (X) ← Rr, X ← X + 1 None 2 ST - X, Rr Store Indirect and Pre-Dec. X ← X - 1, (X) ← Rr None 2 ST Y, Rr Store Indirect (Y) ← Rr None 2 ST Y+, Rr Store Indirect and Post-Inc. (Y) ← Rr, Y ← Y + 1 None 2 ST - Y, Rr Store Indirect and Pre-Dec. Y ← Y - 1, (Y) ← Rr None 2 STD Y+q,Rr Store Indirect with Displacement (Y + q) ← Rr None 2 ST Z, Rr Store Indirect (Z) ← Rr None 2 ST Z+, Rr Store Indirect and Post-Inc. (Z) ← Rr, Z ← Z + 1 None 2 ST -Z, Rr Store Indirect and Pre-Dec. Z ← Z - 1, (Z) ← Rr None 2 STD Z+q,Rr Store Indirect with Displacement (Z + q) ← Rr None 2 STS k, Rr Store Direct to SRAM (k) ← Rr None 2 LPM Load Program Memory R0 ← (Z) None 3 LPM Rd, Z Load Program Memory Rd ← (Z) None 3 LPM Rd, Z+ Load Program Memory and Post-Inc Rd ← (Z), Z ← Z+1 None 3 ELPM Extended Load Program Memory R0 ← (RAMPZ:Z) None 3 ELPM Rd, Z Extended Load Program Memory Rd ← (Z) None 3 ELPM Rd, Z+ Extended Load Program Memory Rd ← (RAMPZ:Z), RAMPZ:Z ←RAMPZ:Z+1 None 3 Mnemonics Operands Description Operation Flags #Clocks425 7593L–AVR–09/12 AT90USB64/128 SPM Store Program Memory (Z) ← R1:R0 None - IN Rd, P In Port Rd ← P None 1 OUT P, Rr Out Port P ← Rr None 1 PUSH Rr Push Register on Stack STACK ← Rr None 2 POP Rd Pop Register from Stack Rd ← STACK None 2 MCU CONTROL INSTRUCTIONS NOP No Operation None 1 SLEEP Sleep (see specific descr. for Sleep function) None 1 WDR Watchdog Reset (see specific descr. for WDR/timer) None 1 BREAK Break For On-chip Debug Only None N/A Mnemonics Operands Description Operation Flags #Clocks426 7593L–AVR–09/12 AT90USB64/128 35. Ordering information 35.1 Atmel AT90USB646 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging complies to the European directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully green. 3. See “Maximum speed vs. VCC” on page 392. Speed [MHz] Power supply [V] Ordering code (2) USB interface Package (1) Operating range 16 (3) 2.7-5.5 AT90USB646-AU AT90USB646-MU Device MD PS Industrial (-40° to +85°C) MD 64 - lead, 14 × 14mm body size, 1.0mm body thickness 0.8mm lead pitch, thin profile plastic quad flat package (TQFP) PS 64 - lead, 9 × 9mm body size, 0.50mm pitch Quad flat no lead package (QFN)427 7593L–AVR–09/12 AT90USB64/128 35.2 Atmel AT90USB647 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging complies to the European directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully green. 3. See “Maximum speed vs. VCC” on page 392. Speed [MHz] Power supply [V] Ordering code (2) USB interface Package (1) Operating range 16 (3) 2.7-5.5 AT90USB647-AU AT90USB647-MU USB OTG MD PS Industrial (-40° to +85°C) MD 64 - lead, 14 × 14mm body size, 1.0mm body thickness 0.8mm lead pitch, thin profile plastic quad flat package (TQFP) PS 64 - lead, 9 × 9mm body size, 0.50mm pitch Quad flat no lead package (QFN)428 7593L–AVR–09/12 AT90USB64/128 35.3 Atmel AT90USB1286 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging complies to the European directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully green. 3. See “Maximum speed vs. VCC” on page 392. Speed [MHz] Power supply [V] Ordering code (2) USB interface Package (1) Operating range 16 (3) 2.7-5.5 AT90USB1286-AU AT90USB1286-MU Device MD PS Industrial (-40° to +85°C) MD 64 - lead, 14 × 14mm body size, 1.0mm body thickness 0.8mm lead pitch, thin profile plastic quad flat package (TQFP) PS 64 - lead, 9 × 9mm body size, 0.50mm pitch Quad flat no lead package (QFN)429 7593L–AVR–09/12 AT90USB64/128 35.4 Atmel AT90USB1287 Notes: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging complies to the European directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully green. 3. See “Maximum speed vs. VCC” on page 392. Speed [MHz] Power supply [V] Ordering code (2) USB interface Package (1) Operating range 16 (3) 2.7-5.5 AT90USB1287-AU AT90USB1287-MU Host (OTG) MD PS Industrial (-40° to +85°C) MD 64 - lead, 14 × 14mm body size, 1.0mm body thickness 0.8mm lead pitch, thin profile plastic quad flat package (TQFP) PS 64 - lead, 9 × 9mm body size, 0.50mm pitch Quad flat no lead package (QFN)430 7593L–AVR–09/12 AT90USB64/128 36. Packaging information 36.1 TQFP64431 7593L–AVR–09/12 AT90USB64/128432 7593L–AVR–09/12 AT90USB64/128 36.2 QFN64433 7593L–AVR–09/12 AT90USB64/128434 7593L–AVR–09/12 AT90USB64/128 37. Errata 37.1 Atmel AT90USB1287/6 errata 37.1.1 AT90USB1287/6 errata history Notes: 1. A blank or any alphanumeric string. 37.1.2 AT90USB1287/6 first release • Incorrect CPU behavior for VBUSTI and IDTI interrupts routines • USB Eye Diagram violation in low-speed mode • Transient perturbation in USB suspend mode generates over consumption • VBUS Session valid threshold voltage • USB signal rate • VBUS residual level • Spike on TWI pins when TWI is enabled • High current consumption in sleep mode • Async timer interrupt wake up from sleep generate multiple interrupts 9. Incorrect CPU behavior for VBUSTI and IDTI interrupts routines The CPU core may incorrectly execute the interrupt vector related to the VBUSTI and IDTI interrupt flags. Problem fix/workaround Do not enable these interrupts, firmware must process these USB events by polling VBUSTI and IDTI flags. 8. USB Eye Diagram violation in low-speed mode The low to high transition of D- violates the USB eye diagram specification when transmitting with low-speed signaling. Problem fix/workaround None. 7. Transient perturbation in USB suspend mode generates overconsumption In device mode and when the USB is suspended, transient perturbation received on the USB lines generates a wake up state. However the idle state following the perturbation does Silicon Release 90USB1286-16MU 90USB1287-16AU 90USB1287-16MU First Release Date Code up to 0648 Date Code up to 0714 and lots 0735 6H2726 (1) Date Code up to 0701 Second Release Date Code from 0709 to 0801 except lots 0801 7H5103 (1) from Date Code 0722 to 0806 except lots 0735 6H2726 (1) Date Code from 0714 to 0810 except lots 0748 7H5103 (1) Third Release Lots 0801 7H5103 (1) and Date Code from 0814 Date Code from 0814 Lots 0748 7H5103 (1) and Date Code from 0814 Fourth Release TBD TBD TBD435 7593L–AVR–09/12 AT90USB64/128 not set the SUSPI bit anymore. The internal USB engine remains in suspend mode but the USB differential receiver is still enabled and generates a typical 300µA extra-power consumption. Detection of the suspend state after the transient perturbation should be performed by software (instead of reading the SUSPI bit). Problem fix/workaround USB waiver allows bus powered devices to consume up to 2.5mA in suspend state. 6. VBUS session valid threshold voltage The VSession valid threshold voltage is internally connected to VBus_Valid (4.4V approx.). That causes the device to attach to the bus only when Vbus is greater than VBusValid instead of V_Session Valid. Thus if VBUS is lower than 4.4V, the device is detached. Problem fix/workaround According to the USB power drop budget, this may require connecting the device toa root hub or a self-powered hub. 5. UBS signal rate The average USB signal rate may sometime be measured out of the USB specifications (12MHz ±30kHz) with short frames. When measured on a long period, the average signal rate value complies with the specifications. This bit rate deviation does not generates communication or functional errors. Problem fix/workaround None. 4. VBUS residual level In USB device and host mode, once a 5V level has been detected to the VBUS pad, a residual level (about 3V) can be measured on the VBUS pin. Problem fix/workaround None. 3. Spike on TWI pins when TWI is enabled 100ns negative spike occurs on SDA and SCL pins when TWI is enabled. Problem fix/workaround No known workaround, enable Atmel AT90USB64/128 TWI first versus the others nodes of the TWI network. 2. High current consumption in sleep mode If a pending interrupt cannot wake the part up from the selected mode, the current consumption will increase during sleep when executing the SLEEP instruction directly after a SEI instruction. Problem fix/workaround Before entering sleep, interrupts not used to wake up the part from the sleep mode should be disabled.436 7593L–AVR–09/12 AT90USB64/128 1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts If the CPU core is in sleep and wakes-up from an asynchronous timer interrupt and then go back in sleep again it may wake up multiple times. Problem fix/workaround A software workaround is to wait with performing the sleep instruction until TCNT2>OCR2+1.437 7593L–AVR–09/12 AT90USB64/128 37.1.3 Atmel AT90USB1287/6 second release • Incorrect CPU behavior for VBUSTI and IDTI interrupts routines • USB Eye Diagram violation in low-speed mode • Transient perturbation in USB suspend mode generates over consumption • VBUS Session valid threshold voltage • Spike on TWI pins when TWI is enabled • High current consumption in sleep mode • Async timer interrupt wake up from sleep generate multiple interrupts 7. Incorrect CPU behavior for VBUSTI and IDTI interrupts routines The CPU core may incorrectly execute the interrupt vector related to the VBUSTI and IDTI interrupt flags. Problem fix/workaround Do not enable these interrupts, firmware must process these USB events by polling VBUSTI and IDTI flags. 6. USB Eye Diagram violation in low-speed mode The low to high transition of D- violates the USB eye diagram specification when transmitting with low-speed signaling. Problem fix/workaround None. 5. Transient perturbation in USB suspend mode generates overconsumption In device mode and when the USB is suspended, transient perturbation received on the USB lines generates a wake up state. However the idle state following the perturbation does not set the SUSPI bit anymore. The internal USB engine remains in suspend mode but the USB differential receiver is still enabled and generates a typical 300µA extra-power consumption. Detection of the suspend state after the transient perturbation should be performed by software (instead of reading the SUSPI bit). Problem fix/workaround USB waiver allows bus powered devices to consume up to 2.5mA in suspend state. 4. VBUS session valid threshold voltage The VSession valid threshold voltage is internally connected to VBus_Valid (4.4V approx.). That causes the device to attach to the bus only when Vbus is greater than VBusValid instead of V_Session Valid. Thus if VBUS is lower than 4.4V, the device is detached. Problem fix/workaround According to the USB power drop budget, this may require connecting the device toa root hub or a self-powered hub. 3. Spike on TWI pins when TWI is enabled 100ns negative spike occurs on SDA and SCL pins when TWI is enabled.438 7593L–AVR–09/12 AT90USB64/128 Problem fix/workaround No known workaround, enable Atmel AT90USB64/128 TWI first versus the others nodes of the TWI network. 2. High current consumption in sleep mode If a pending interrupt cannot wake the part up from the selected mode, the current consumption will increase during sleep when executing the SLEEP instruction directly after a SEI instruction. Problem fix/workaround Before entering sleep, interrupts not used to wake up the part from the sleep mode should be disabled. 1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts If the CPU core is in sleep and wakes-up from an asynchronous timer interrupt and then go back in sleep again it may wake up multiple times. Problem fix/workaround A software workaround is to wait with performing the sleep instruction until TCNT2>OCR2+1.439 7593L–AVR–09/12 AT90USB64/128 37.1.4 Atmel AT90USB1287/6 Third Release • Incorrect CPU behavior for VBUSTI and IDTI interrupts routines • Transient perturbation in USB suspend mode generates over consumption • Spike on TWI pins when TWI is enabled • High current consumption in sleep mode • Async timer interrupt wake up from sleep generate multiple interrupts 5. Incorrect CPU behavior for VBUSTI and IDTI interrupts routines The CPU core may incorrectly execute the interrupt vector related to the VBUSTI and IDTI interrupt flags. Problem fix/workaround Do not enable these interrupts, firmware must process these USB events by polling VBUSTI and IDTI flags. 4. Transient perturbation in USB suspend mode generates overconsumption In device mode and when the USB is suspended, transient perturbation received on the USB lines generates a wake up state. However the idle state following the perturbation does not set the SUSPI bit. The internal USB engine remains in suspend mode but the USB differential receiver is still enabled and generates a typical 300µA extra-power consumption. Detection of the suspend state after the transient perturbation should be performed by software (instead of reading the SUSPI bit). Problem fix/workaround USB waiver allows bus powered devices to consume up to 2.5mA in suspend state. 3. Spike on TWI pins when TWI is enabled 100ns negative spike occurs on SDA and SCL pins when TWI is enabled. Problem fix/workaround No known workaround, enable AT90USB64/128 TWI first, before the others nodes of the TWI network. 2. High current consumption in sleep mode If a pending interrupt cannot wake the part up from the selected mode, the current consumption will increase during sleep when executing the SLEEP instruction directly after a SEI instruction. Problem fix/workaround Before entering sleep, interrupts not used to wake up the part from sleep mode should be disabled. 1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts If the CPU core is in sleep mode and wakes-up from an asynchronous timer interrupt and then goes back into sleep mode, it may wake up multiple times.440 7593L–AVR–09/12 AT90USB64/128 Problem fix/workaround A software workaround is to wait before performing the sleep instruction: until TCNT2>OCR2+1.441 7593L–AVR–09/12 AT90USB64/128 37.1.5 Atmel AT90USB1287/6 Fourth Release • Transient perturbation in USB suspend mode generates over consumption • Spike on TWI pins when TWI is enabled • High current consumption in sleep mode • Async timer interrupt wake up from sleep generate multiple interrupts 4. Transient perturbation in USB suspend mode generates overconsumption In device mode and when the USB is suspended, transient perturbation received on the USB lines generates a wake up state. However the idle state following the perturbation does not set the SUSPI bit. The internal USB engine remains in suspend mode but the USB differential receiver is still enabled and generates a typical 300µA extra-power consumption. Detection of the suspend state after the transient perturbation should be performed by software (instead of reading the SUSPI bit). Problem fix/workaround USB waiver allows bus powered devices to consume up to 2.5mA in suspend state. 3. Spike on TWI pins when TWI is enabled 100ns negative spike occurs on SDA and SCL pins when TWI is enabled. Problem fix/workaround No known workaround, enable Atmel AT90USB64/128 TWI first, before the others nodes of the TWI network. 2. High current consumption in sleep mode If a pending interrupt cannot wake the part up from the selected mode, the current consumption will increase during sleep when executing the SLEEP instruction directly after a SEI instruction. Problem fix/workaround Before entering sleep, interrupts not used to wake up the part from sleep mode should be disabled. 1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts If the CPU core is in sleep mode and wakes-up from an asynchronous timer interrupt and then goes back into sleep mode, it may wake up multiple times. Problem fix/workaround A software workaround is to wait before performing the sleep instruction: until TCNT2>OCR2+1.442 7593L–AVR–09/12 AT90USB64/128 37.2 Atmel AT90USB646/7 errata 37.2.1 AT90USB646/7 errata history TBD Note ‘*’ means a blank or any alphanumeric string. 37.2.2 AT90USB646/7 first release. • Incorrect interrupt routine execution for VBUSTI, IDTI interrupts flags • USB Eye Diagram violation in low-speed mode • Transient perturbation in USB suspend mode generates over consumption • Spike on TWI pins when TWI is enabled • High current consumption in sleep mode • Async timer interrupt wake up from sleep generate multiple interrupts 6. Incorrect CPU behavior for VBUSTI and IDTI interrupts routines The CPU core may incorrectly execute the interrupt vector related to the VBUSTI and IDTI interrupt flags. Problem fix/workaround Do not enable these interrupts, firmware must process these USB events by polling VBUSTI and IDTI flags. 5. USB Eye Diagram violation in low-speed mode The low to high transition of D- violates the USB eye diagram specification when transmitting with low-speed signaling. Problem fix/workaround None. 4. Transient perturbation in USB suspend mode generates overconsumption In device mode and when the USB is suspended, transient perturbation received on the USB lines generates a wake up state. However the idle state following the perturbation does not set the SUSPI bit anymore. The internal USB engine remains in suspend mode but the USB differential receiver is still enabled and generates a typical 300µA extra-power consumption. Detection of the suspend state after the transient perturbation should be performed by software (instead of reading the SUSPI bit). Problem fix/workaround USB waiver allows bus powered devices to consume up to 2.5mA in suspend state. 3. Spike on TWI pins when TWI is enabled 100ns negative spike occurs on SDA and SCL pins when TWI is enabled. Silicon Release 90USB646-16MU 90USB647-16AU 90USB647-16MU First Release Second Release443 7593L–AVR–09/12 AT90USB64/128 Problem fix/workaround No known workaround, enable Atmel AT90USB64/128 TWI first versus the others nodes of the TWI network. 2. High current consumption in sleep mode If a pending interrupt cannot wake the part up from the selected mode, the current consumption will increase during sleep when executing the SLEEP instruction directly after a SEI instruction. Problem fix/workaround Before entering sleep, interrupts not used to wake up the part from the sleep mode should be disabled. 1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts If the CPU core is in sleep and wakes-up from an asynchronous timer interrupt and then go back in sleep mode again it may wake up several times. Problem fix/workaround A software workaround is to wait with performing the sleep instruction until TCNT2>OCR2+1.444 7593L–AVR–09/12 AT90USB64/128 37.2.3 Atmel AT90USB646/7 Second Release. • USB Eye Diagram violation in low-speed mode • Transient perturbation in USB suspend mode generates over consumption • Spike on TWI pins when TWI is enabled • High current consumption in sleep mode • Async timer interrupt wake up from sleep generate multiple interrupts 5. USB Eye Diagram violation in low-speed mode The low to high transition of D- violates the USB eye diagram specification when transmitting with low-speed signaling. Problem fix/workaround None. 4. Transient perturbation in USB suspend mode generates overconsumption In device mode and when the USB is suspended, transient perturbation received on the USB lines generates a wake up state. However the idle state following the perturbation does not set the SUSPI bit anymore. The internal USB engine remains in suspend mode but the USB differential receiver is still enabled and generates a typical 300µA extra-power consumption. Detection of the suspend state after the transient perturbation should be performed by software (instead of reading the SUSPI bit). Problem fix/workaround USB waiver allows bus powered devices to consume up to 2.5mA in suspend state. 3. Spike on TWI pins when TWI is enabled 100ns negative spike occurs on SDA and SCL pins when TWI is enabled. Problem fix/workaround No known workaround, enable Atmel AT90USB64/128 TWI first versus the others nodes of the TWI network. 2. High current consumption in sleep mode If a pending interrupt cannot wake the part up from the selected mode, the current consumption will increase during sleep when executing the SLEEP instruction directly after a SEI instruction. Problem fix/workaround Before entering sleep, interrupts not used to wake up the part from the sleep mode should be disabled. 1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts If the CPU core is in sleep and wakes-up from an asynchronous timer interrupt and then go back in sleep mode again it may wake up several times. Problem fix/workaround A software workaround is to wait with performing the sleep instruction until TCNT2>OCR2+1.445 7593L–AVR–09/12 AT90USB64/128 38. Datasheet revision history for Atmel AT90USB64/128 Please note that the referring page numbers in this section are referred to this document. The referring revision in this section are referring to the document revision. 38.1 Changes from 7593A to 7593B 1. Changed default configuration for fuse bytes and security byte. 2. Suppression of timer 4,5 registers which does not exist. 3. Updated typical application schematics in USB section 38.2 Changes from 7593B to 7593C 1. Update to package drawings, MQFP64 and TQFP64. 38.3 Changes from 7593C to 7593D 1. For further product compatibility, changed USB PLL possible prescaler configurations. Only 8MHz and 16MHz crystal frequencies allows USB operation (see Table 7-11 on page 50). 38.4 Changes from 7593D to 7593E 1. Updated PLL Prescaler table: configuration words are different between AT90USB64x and AT90USB128x to enable the PLL with a 16MHz source. 2. Cleaned up some bits from USB registers, and updated information about OTG timers, remote wake-up, reset and connection timings. 3. Updated clock distribution tree diagram (USB prescaler source and configuration register). 4. Cleaned up register summary. 5. Suppressed PCINT23:8 that do not exist from External Interrupts. 6. Updated Electrical Characteristics. 7. Added Typical Characteristics. 8. Update Errata section. 38.5 Changes from 7593E to 7593F 1. Removed ’Preliminary’ from document status. 2. Clarification in Stand by mode regarding USB. 38.6 Changes from 7593F to 7593G 1. Updated Errata section. 38.7 Changes from 7593G to 7593H 1. Added Signature information for 64K devices. 2. Fixed figure for typical bus powered application 3. Added min/max values for BOD levels 4. Added ATmega32U6 product 5. Update Errata section 6. Modified descriptions for HWUPE and WAKEUPE interrupts enable (these interrupts should be enabled only to wake up the CPU core from power down mode).446 7593L–AVR–09/12 AT90USB64/128 7. Added description to access unique serial number located in Signature Row see “Reading the Signature Row from software” on page 354. 38.8 Changes from 7593H to 7593I 1. Updated Table 9-2 in “Brown-out detection” on page 60. Unused BOD levels removed. 38.9 Changes from 7593I to 7593J 1. Updated Table 9-2 in “Brown-out detection” on page 60. BOD level 100 removed. 2. Updated “Ordering information” on page 426. 3. Removed ATmega32U6 errata section. 38.10 Changes from 7593J to 7593K 1. Corrected Figure 6-7 on page 34, Figure 6-8 on page 34 and Figure 6-9 on page 35. 2. Corrected ordering information for Section 35.3 ”Atmel AT90USB1286” on page 428, Section 35.4 ”Atmel AT90USB1287” on page 429 andSection 35.2 ”Atmel AT90USB647” on page 427. 3. Removed the ATmega32U6 device and updated the datasheet accordingly. 4. Updated Assembly Code Example in “Watchdog reset” on page 61. 38.11 Changes from 7593K to 7593L 1. Updated the “Ordering information” on page 426. Changed the speed from 20MHz to 16MHz. 2. Replaced ATmegaAT90USBxxxx by AT90USBxxxx through the datasheet. 3. Updated the first paragraph of “Overview” on page 307. Port A replaced by Port F. 4. Updated ADC equation in “ADC conversion result” on page 318. The equation has 1024 instead of 1023. 5. Created “Packaging Information” chapter. 6. Replaced the “QFN64” Packaging by an updated QFN64 Packaging drawing. 7. Updated “Errata” on page 434. AT90USB1286/7 has a fourth release, while AT90USB646/7 updated with a second release. 8. In Section “Overview” on page 307, “Port A” has been replaced by “Port F” in the first section. 9. In Section “Atmel AT90USB647” on page 427 the USB interface has been changed to USB OTG. 10. In Section “Atmel AT90USB1286” on page 428 the USB interface has been changed to Device. 11. In Section “Atmel AT90USB1287” on page 429 the USB interface has been changed to Host OTG. 12. General update according to new template.i 7593L–AVR–09/12 AT90USB64X/128X Table of contents Features ..................................................................................................... 1 1 Pin configurations ................................................................................... 3 2 Overview ................................................................................................... 5 2.1 Block diagram ..........................................................................................................6 2.2 Pin descriptions .......................................................................................................8 3 Resources ............................................................................................... 10 4 About code examples ............................................................................ 10 5 AVR CPU core ........................................................................................ 11 5.1 Introduction ............................................................................................................11 5.2 Architectural overview ...........................................................................................11 5.3 ALU – Arithmetic Logic Unit ..................................................................................12 5.4 Status register .......................................................................................................13 5.5 General purpose register file .................................................................................14 5.6 Stack pointer .........................................................................................................15 5.7 Instruction execution timing ...................................................................................16 5.8 Reset and interrupt handling .................................................................................17 6 Atmel AVR AT90USB64/128 memories ................................................ 20 6.1 In-system re-programmable flash program memory .............................................20 6.2 SRAM data memory ..............................................................................................21 6.3 EEPROM data memory .........................................................................................24 6.4 I/O memory ............................................................................................................30 6.5 External memory interface ....................................................................................31 7 System clock and clock options .......................................................... 40 7.1 Clock systems and their distribution ......................................................................40 7.2 Clock sources ........................................................................................................41 7.3 Low power crystal oscillator ..................................................................................42 7.4 Low frequency crystal oscillator ............................................................................44 7.5 Calibrated internal RC oscillator ............................................................................45 7.6 External clock ........................................................................................................46 7.7 Clock output buffer ................................................................................................47 7.8 Timer/counter oscillator .........................................................................................47 7.9 System clock prescaler .........................................................................................47ii 7593L–AVR–09/12 AT90USB64X/128X 7.10 PLL ......................................................................................................................49 8 Power management and sleep modes ................................................. 51 8.1 Idle mode ...............................................................................................................52 8.2 ADC noise reduction mode ...................................................................................52 8.3 Power-down mode ................................................................................................52 8.4 Power-save mode .................................................................................................52 8.5 Standby mode .......................................................................................................53 8.6 Extended Standby mode .......................................................................................53 8.7 Power Reduction Register .....................................................................................54 8.8 Minimizing power consumption .............................................................................55 9 System control and reset ...................................................................... 57 9.1 Resetting the AVR .................................................................................................57 9.2 Reset sources .......................................................................................................57 9.3 Power-on reset ......................................................................................................58 9.4 External reset ........................................................................................................59 9.5 Brown-out detection ..............................................................................................60 9.6 Watchdog reset .....................................................................................................61 9.7 Internal voltage reference ......................................................................................62 9.8 Watchdog timer .....................................................................................................63 10 Interrupts ................................................................................................ 68 10.1 Interrupt vectors in AT90USB64/128 ...................................................................68 11 I/O-ports .................................................................................................. 71 11.1 Introduction ..........................................................................................................71 11.2 Ports as general digital I/O ..................................................................................72 11.3 Alternate port functions .......................................................................................76 11.4 Register description for I/O-ports ........................................................................89 12 External interrupts ................................................................................. 92 13 Timer/Counter0, Timer/Counter1, and Timer/Counter3 prescalers ... 96 13.1 Internal clock source ...........................................................................................96 13.2 Prescaler reset ....................................................................................................96 13.3 External clock source ..........................................................................................96 13.4 GTCCR – General Timer/Counter Control Register ............................................97 14 8-bit Timer/Counter0 with PWM ............................................................ 98 14.1 Overview .............................................................................................................98iii 7593L–AVR–09/12 AT90USB64X/128X 14.2 Timer/Counter clock sources ...............................................................................99 14.3 Counter unit .........................................................................................................99 14.4 Output compare unit ..........................................................................................100 14.5 Compare Match Output Unit ..............................................................................102 14.6 Modes of operation ............................................................................................103 14.7 Timer/Counter timing diagrams .........................................................................107 14.8 8-bit Timer/Counter register description ............................................................108 15 16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3) ........... 115 15.1 Overview ...........................................................................................................115 15.2 Accessing 16-bit registers .................................................................................117 15.3 Timer/Counter clock sources .............................................................................120 15.4 Counter unit .......................................................................................................121 15.5 Input Capture unit ..............................................................................................122 15.6 Output Compare units .......................................................................................124 15.7 Compare Match Output unit ..............................................................................126 15.8 Modes of operation ............................................................................................127 15.9 Timer/Counter timing diagrams .........................................................................134 15.10 16-bit Timer/Counter register description ........................................................136 16 8-bit Timer/Counter2 with PWM and asynchronous operation ........ 145 16.1 Overview ...........................................................................................................145 16.2 Timer/Counter clock sources .............................................................................146 16.3 Counter unit .......................................................................................................146 16.4 Output Compare unit .........................................................................................147 16.5 Compare Match Output unit ..............................................................................149 16.6 Modes of operation ............................................................................................150 16.7 Timer/Counter timing diagrams .........................................................................154 16.8 8-bit Timer/Counter register description ............................................................156 16.9 Asynchronous operation of the Timer/Counter ..................................................161 16.10 Timer/Counter prescaler ..................................................................................164 17 Output Compare Modulator (OCM1C0A) ........................................... 166 17.1 Overview ...........................................................................................................166 17.2 Description ........................................................................................................166 18 SPI – Serial Peripheral Interface ......................................................... 168 18.1 SS Pin Functionality ..........................................................................................172 18.2 Data modes .......................................................................................................175iv 7593L–AVR–09/12 AT90USB64X/128X 19 USART ................................................................................................... 177 19.1 Overview ...........................................................................................................177 19.2 Clock generation ...............................................................................................178 19.3 Frame formats ...................................................................................................180 19.4 USART initialization ...........................................................................................181 19.5 Data transmission – The USART transmitter ....................................................182 19.6 Data reception – The USART receiver ..............................................................185 19.7 Asynchronous data reception ............................................................................189 19.8 Multi-processor Communication mode ..............................................................192 19.9 USART register description ...............................................................................193 19.10 Examples of baud rate setting .........................................................................198 20 USART in SPI mode ............................................................................. 202 20.1 Overview ...........................................................................................................202 20.2 Clock generation ...............................................................................................202 20.3 SPI data modes and timing ...............................................................................203 20.4 Frame formats ...................................................................................................203 20.5 Data transfer ......................................................................................................205 20.6 USART MSPIM register description ..................................................................207 20.7 AVR USART MSPIM vs. AVR SPI ....................................................................209 21 2-wire serial interface .......................................................................... 211 21.1 Features ............................................................................................................211 21.2 2-wire Serial Interface bus definition .................................................................211 21.3 Data transfer and frame format .........................................................................212 21.4 Multi-master bus systems, arbitration and synchronization ...............................215 21.5 Overview of the TWI module .............................................................................216 21.6 TWI register description ....................................................................................219 21.7 Using the TWI ....................................................................................................222 21.8 Transmission modes .........................................................................................225 21.9 Multi-master systems and arbitration .................................................................239 22 USB controller ...................................................................................... 241 22.1 Features ............................................................................................................241 22.2 Block diagram ....................................................................................................241 22.3 Typical application implementation ...................................................................242 22.4 General operating modes ..................................................................................246 22.5 Power modes ....................................................................................................250v 7593L–AVR–09/12 AT90USB64X/128X 22.6 Speed control ....................................................................................................251 22.7 Memory management .......................................................................................252 22.8 PAD suspend ....................................................................................................253 22.9 OTG timers customizing ....................................................................................254 22.10 Plug-in detection ..............................................................................................255 22.11 ID detection .....................................................................................................256 22.12 Registers description .......................................................................................256 22.13 USB Software Operating modes .....................................................................261 23 USB device operating modes ............................................................. 262 23.1 Introduction ........................................................................................................262 23.2 Power-on and reset ...........................................................................................262 23.3 Endpoint reset ...................................................................................................262 23.4 USB reset ..........................................................................................................263 23.5 Endpoint selection .............................................................................................263 23.6 Endpoint activation ............................................................................................263 23.7 Address setup ...................................................................................................264 23.8 Suspend, wake-up and resume .........................................................................265 23.9 Detach ...............................................................................................................265 23.10 Remote Wake-up ............................................................................................266 23.11 STALL request ................................................................................................266 23.12 CONTROL endpoint management ..................................................................267 23.13 OUT endpoint management ............................................................................268 23.14 IN endpoint management ................................................................................269 23.15 Isochronous mode ...........................................................................................271 23.16 Overflow ..........................................................................................................272 23.17 Interrupts .........................................................................................................272 23.18 Registers .........................................................................................................273 24 USB host operating modes ................................................................. 285 24.1 Pipe description .................................................................................................285 24.2 Detach ...............................................................................................................285 24.3 Power-on and reset ...........................................................................................285 24.4 Device detection ................................................................................................286 24.5 Pipe selection ....................................................................................................286 24.6 Pipe configuration ..............................................................................................286 24.7 USB reset ..........................................................................................................288vi 7593L–AVR–09/12 AT90USB64X/128X 24.8 Address setup ...................................................................................................288 24.9 Remote wake-up detection ................................................................................288 24.10 USB pipe reset ................................................................................................288 24.11 Pipe data access .............................................................................................288 24.12 Control pipe management ...............................................................................289 24.13 OUT pipe management ...................................................................................289 24.14 IN Pipe management .......................................................................................290 24.15 Interrupt system ...............................................................................................291 24.16 Registers .........................................................................................................292 25 Analog Comparator ............................................................................. 304 25.1 Analog Comparator multiplexed input ...............................................................306 26 ADC – Analog to Digital Converter ..................................................... 307 26.1 Features ............................................................................................................307 26.2 Overview ...........................................................................................................307 26.3 Operation ...........................................................................................................309 26.4 Starting a conversion .........................................................................................309 26.5 Prescaling and conversion timing ......................................................................310 26.6 Changing channel or reference selection ..........................................................313 26.7 ADC noise canceler ...........................................................................................314 26.8 ADC conversion result .......................................................................................318 26.9 ADC register description ...................................................................................321 27 JTAG interface and on-chip debug system ....................................... 327 27.1 Overview ...........................................................................................................327 27.2 TAP – Test Access Port ....................................................................................327 27.3 TAP Controller ...................................................................................................329 27.4 Using the Boundary-scan chain ........................................................................330 27.5 Using the on-chip debug system .......................................................................330 27.6 On-chip debug specific JTAG instructions .........................................................331 27.7 On-chip Debug related Register in I/O memory ................................................332 27.8 Using the JTAG programming capabilities ........................................................332 27.9 Bibliography .......................................................................................................332 28 IEEE 1149.1 (JTAG) boundary-scan ................................................... 333 28.1 Features ............................................................................................................333 28.2 System overview ...............................................................................................333 28.3 Data registers ....................................................................................................333vii 7593L–AVR–09/12 AT90USB64X/128X 28.4 Boundary-scan specific JTAG instructions ........................................................335 28.5 Boundary-scan Related Register in I/O memory ...............................................336 28.6 Boundary-scan chain .........................................................................................337 28.7 Atmel AT90USB64/128 Boundary-scan order ...................................................340 28.8 Boundary-scan description language files .........................................................342 29 Boot Loader support – read-while-write self-programming ............. 343 29.1 Boot Loader features .........................................................................................343 29.2 Application and Boot Loader flash sections ......................................................343 29.3 Read-while-write and no read-while-write flash sections ...................................343 29.4 Boot Loader lock bits .........................................................................................346 29.5 Entering the Boot Loader program ....................................................................347 29.6 Addressing the flash during self-programming ..................................................350 29.7 Self-programming the flash ...............................................................................351 30 Memory programming ......................................................................... 359 30.1 Program and data memory lock bits ..................................................................359 30.2 Fuse bits ............................................................................................................360 30.3 Signature bytes .................................................................................................362 30.4 Calibration byte .................................................................................................362 30.5 Parallel programming parameters, pin mapping, and commands .....................362 30.6 Parallel programming ........................................................................................365 30.7 Serial downloading ............................................................................................373 30.8 Serial programming pin mapping ......................................................................374 30.9 Programming via the JTAG interface ................................................................377 31 Electrical characteristics for Atmel AT90USB64/128 ....................... 390 31.1 Absolute maximum ratings* ...............................................................................390 31.2 DC characteristics .............................................................................................390 31.3 External clock drive waveforms .........................................................................392 31.4 External clock drive ...........................................................................................392 31.5 Maximum speed vs. VCC ...........................................................................................................................392 31.6 2-wire serial interface characteristics ................................................................393 31.7 SPI timing characteristics ..................................................................................395 31.8 Hardware boot entrance timing characteristics .................................................396 31.9 ADC characteristics ...........................................................................................397 31.10 External data memory timing ...........................................................................399 32 Atmel AT90USB64/128 typical characteristics ................................. 404viii 7593L–AVR–09/12 AT90USB64X/128X 32.1 Input voltage levels ............................................................................................405 32.2 Output voltage levels .........................................................................................406 32.3 Power-down supply current ...............................................................................408 32.4 Power-save supply current ................................................................................409 32.5 Idle supply current .............................................................................................410 32.6 Active supply current .........................................................................................410 32.7 Reset supply current .........................................................................................411 32.8 I/O pull-up current ..............................................................................................411 32.9 Bandgap voltage ...............................................................................................412 32.10 Internal ARef voltage .......................................................................................413 32.11 USB regulator ..................................................................................................413 32.12 BOD levels ......................................................................................................414 32.13 Watchdog timer frequency ..............................................................................416 32.14 Internal RC oscillator frequency ......................................................................416 32.15 Power-on reset ................................................................................................418 33 Register summary ................................................................................ 419 34 Instruction set summary ..................................................................... 423 35 Ordering information ........................................................................... 426 35.1 Atmel AT90USB646 ..........................................................................................426 35.2 Atmel AT90USB647 ..........................................................................................427 35.3 Atmel AT90USB1286 ........................................................................................428 35.4 Atmel AT90USB1287 ........................................................................................429 36 Packaging information ........................................................................ 430 36.1 TQFP64 .............................................................................................................430 36.2 QFN64 ...............................................................................................................432 37 Errata ..................................................................................................... 434 37.1 Atmel AT90USB1287/6 errata ...........................................................................434 37.2 Atmel AT90USB646/7 errata .............................................................................442 38 Datasheet revision history for Atmel AT90USB64/128 ..................... 445 38.1 Changes from 7593A to 7593B .........................................................................445 38.2 Changes from 7593B to 7593C .........................................................................445 38.3 Changes from 7593C to 7593D .........................................................................445 38.4 Changes from 7593D to 7593E .........................................................................445 38.5 Changes from 7593E to 7593F .........................................................................445ix 7593L–AVR–09/12 AT90USB64X/128X 38.6 Changes from 7593F to 7593G .........................................................................445 38.7 Changes from 7593G to 7593H ........................................................................445 38.8 Changes from 7593H to 7593I ..........................................................................446 38.9 Changes from 7593I to 7593J ...........................................................................446 38.10 Changes from 7593J to 7593K ........................................................................446 38.11 Changes from 7593K to 7593L .......................................................................446 Table of contents ....................................................................................... i7593L–AVR–09/12 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: (+1)(408) 441-0311 Fax: (+1)(408) 487-2600 www.atmel.com Atmel Asia Limited Unit 1-5 & 16, 19/F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax: (+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax: (+49) 89-3194621 Atmel Japan 16F, Shin Osaki Kangyo Bldg. 1-6-4 Osaki Shinagawa-ku Tokyo 104-0032 JAPAN Tel: (+81) 3-6417-0300 Fax: (+81) 3-6417-0370 © 2012 Atmel Corporation. All rights reserved. Atmel®, Atmel logo and combinations thereof, AVR®, AVR Studio®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Windows® is a registered trademark of Microsoft Corporation in U.S. and or other countries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice. 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Features • High performance, low power Atmel® AVR® 8-bit microcontroller • Advanced RISC architecture – 131 powerful instructions – most single clock cycle execution – 32 × 8 general purpose working registers – Fully static operation – Up to 20 MIPS throughput at 20MHz – On-chip 2-cycle multiplier • High endurance non-volatile memory segments – 4/8/16 Kbytes of in-system self-programmable flash program memory – 256/512/512 bytes EEPROM – 512/1K/1Kbytes internal SRAM – Write/erase cyles: 10,000 flash/100,000 EEPROM – Data retention: 20 years at 85°C/100 years at 25°C() – Optional boot code section with independent lock bits In-system programming by on-chip boot program True read-while-write operation – Programming lock for software security • QTouch® library support – Capacitive touch buttons, sliders and wheels – QTouch and QMatrix acquisition – Up to 64 sense channels • Peripheral features – Two 8-bit timer/counters with separate prescaler and compare mode – One 16-bit timer/counter with separate prescaler, compare mode, and capture mode – Real time counter with separate oscillator – Six PWM channels – 8-channel 10-bit ADC in TQFP and QFN/MLF package – 6-channel 10-bit ADC in PDIP Package – Programmable serial USART – Master/slave SPI serial interface – Byte-oriented 2-wire serial interface (Philips I2 C compatible) – Programmable watchdog timer with separate on-chip oscillator – On-chip analog comparator – Interrupt and wake-up on pin change • Special microcontroller features – DebugWIRE on-chip debug system – Power-on reset and programmable brown-out detection – Internal calibrated oscillator – External and internal interrupt sources – Five sleep modes: Idle, ADC noise reduction, power-save, power-down, and standby • I/O and packages – 23 programmable I/O lines – 28-pin PDIP, 32-lead TQFP, 28-pad QFN/MLF and 32-pad QFN/MLF • Operating voltage: – 1.8V - 5.5V for Atmel ATmega48V/88V/168V – 2.7V - 5.5V for Atmel ATmega48/88/168 • Temperature range: – -40°C to 85°C • Speed grade: – ATmega48V/88V/168V: 0 - 4MHz @ 1.8V - 5.5V, 0 - 10MHz @ 2.7V - 5.5V – ATmega48/88/168: 0 - 10MHz @ 2.7V - 5.5V, 0 - 20MHz @ 4.5V - 5.5V • Low power consumption – Active mode: 250µA at 1MHz, 1.8V 15µA at 32kHz, 1.8V (including oscillator) – Power-down mode: 0.1µA at 1.8V Note: 1. See “Data retention” on page 8 for details. 8-bit Atmel Microcontroller with 4/8/16K Bytes In-System Programmable Flash ATmega48/V ATmega88/V ATmega168/V Rev. 2545T–AVR–05/112 2545T–AVR–05/11 ATmega48/88/168 1. Pin configurations Figure 1-1. Pinout Atmel ATmega48/88/168. 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 (PCINT19/OC2B/INT1) PD3 (PCINT20/XCK/T0) PD4 GND VCC GND VCC (PCINT6/XTAL1/TOSC1) PB6 (PCINT7/XTAL2/TOSC2) PB7 PC1 (ADC1/PCINT9) PC0 (ADC0/PCINT8) ADC7 GND AREF ADC6 AVCC PB5 (SCK/PCINT5) 32 31 30 29 28 27 26 25 9 10 11 12 13 14 15 16 (PCINT21/OC0B/T1) PD5 (PCINT22/OC0A/AIN0) PD6 (PCINT23/AIN1) PD7 (PCINT0/CLKO/ICP1) PB0 (PCINT1/OC1A) PB1 (PCINT2/SS/OC1B) PB2 (PCINT3/OC2A/MOSI) PB3 (PCINT4/MISO) PB4 PD2 (INT0/PCINT18) PD1 (TXD/PCINT17) PD0 (RXD/PCINT16) PC6 (RESET/PCINT14) PC5 (ADC5/SCL/PCINT13) PC4 (ADC4/SDA/PCINT12) PC3 (ADC3/PCINT11) PC2 (ADC2/PCINT10) TQFP Top View 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 (PCINT14/RESET) PC6 (PCINT16/RXD) PD0 (PCINT17/TXD) PD1 (PCINT18/INT0) PD2 (PCINT19/OC2B/INT1) PD3 (PCINT20/XCK/T0) PD4 VCC GND (PCINT6/XTAL1/TOSC1) PB6 (PCINT7/XTAL2/TOSC2) PB7 (PCINT21/OC0B/T1) PD5 (PCINT22/OC0A/AIN0) PD6 (PCINT23/AIN1) PD7 (PCINT0/CLKO/ICP1) PB0 PC5 (ADC5/SCL/PCINT13) PC4 (ADC4/SDA/PCINT12) PC3 (ADC3/PCINT11) PC2 (ADC2/PCINT10) PC1 (ADC1/PCINT9) PC0 (ADC0/PCINT8) GND AREF AVCC PB5 (SCK/PCINT5) PB4 (MISO/PCINT4) PB3 (MOSI/OC2A/PCINT3) PB2 (SS/OC1B/PCINT2) PB1 (OC1A/PCINT1) PDIP 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 32 31 30 29 28 27 26 25 9 10 11 12 13 14 15 16 32 MLF Top View (PCINT19/OC2B/INT1) PD3 (PCINT20/XCK/T0) PD4 GND VCC GND VCC (PCINT6/XTAL1/TOSC1) PB6 (PCINT7/XTAL2/TOSC2) PB7 PC1 (ADC1/PCINT9) PC0 (ADC0/PCINT8) ADC7 GND AREF ADC6 AVCC PB5 (SCK/PCINT5) (PCINT21/OC0B/T1) PD5 (PCINT22/OC0A/AIN0) PD6 (PCINT23/AIN1) PD7 (PCINT0/CLKO/ICP1) PB0 (PCINT1/OC1A) PB1 (PCINT2/SS/OC1B) PB2 (PCINT3/OC2A/MOSI) PB3 (PCINT4/MISO) PB4 PD2 (INT0/PCINT18) PD1 (TXD/PCINT17) PD0 (RXD/PCINT16) PC6 (RESET/PCINT14) PC5 (ADC5/SCL/PCINT13) PC4 (ADC4/SDA/PCINT12) PC3 (ADC3/PCINT11) PC2 (ADC2/PCINT10) NOTE: Bottom pad should be soldered to ground. 1 2 3 4 5 6 7 21 20 19 18 17 16 15 28 27 26 25 24 23 22 8 9 10 11 12 13 14 28 MLF Top View (PCINT19/OC2B/INT1) PD3 (PCINT20/XCK/T0) PD4 VCC GND (PCINT6/XTAL1/TOSC1) PB6 (PCINT7/XTAL2/TOSC2) PB7 (PCINT21/OC0B/T1) PD5 (PCINT22/OC0A/AIN0) PD6 (PCINT23/AIN1) PD7 (PCINT0/CLKO/ICP1) PB0 (PCINT1/OC1A) PB1 (PCINT2/SS/OC1B) PB2 (PCINT3/OC2A/MOSI) PB3 (PCINT4/MISO) PB4 PD2 (INT0/PCINT18) PD1 (TXD/PCINT17) PD0 (RXD/PCINT16) PC6 (RESET/PCINT14) PC5 (ADC5/SCL/PCINT13) PC4 (ADC4/SDA/PCINT12) PC3 (ADC3/PCINT11) PC2 (ADC2/PCINT10) PC1 (ADC1/PCINT9) PC0 (ADC0/PCINT8) GND AREF AVCC PB5 (SCK/PCINT5) NOTE: Bottom pad should be soldered to ground.3 2545T–AVR–05/11 ATmega48/88/168 1.1 Pin descriptions 1.1.1 VCC Digital supply voltage. 1.1.2 GND Ground. 1.1.3 Port B (PB7:0) XTAL1/XTAL2/TOSC1/TOSC2 Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Depending on the clock selection fuse settings, PB6 can be used as input to the inverting Oscillator amplifier and input to the internal clock operating circuit. Depending on the clock selection fuse settings, PB7 can be used as output from the inverting Oscillator amplifier. If the Internal Calibrated RC Oscillator is used as chip clock source, PB7..6 is used as TOSC2..1 input for the Asynchronous Timer/Counter2 if the AS2 bit in ASSR is set. The various special features of Port B are elaborated in “Alternate functions of port B” on page 78 and “System clock and clock options” on page 27. 1.1.4 Port C (PC5:0) Port C is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The PC5..0 output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running. 1.1.5 PC6/RESET If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical characteristics of PC6 differ from those of the other pins of Port C. If the RSTDISBL Fuse is unprogrammed, PC6 is used as a Reset input. A low level on this pin for longer than the minimum pulse length will generate a Reset, even if the clock is not running. The minimum pulse length is given in Table 29-3 on page 307. Shorter pulses are not guaranteed to generate a Reset. The various special features of Port C are elaborated in “Alternate functions of port C” on page 81. 1.1.6 Port D (PD7:0) Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are externally pulled low will source current if the pull-up4 2545T–AVR–05/11 ATmega48/88/168 resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running. The various special features of Port D are elaborated in “Alternate functions of port D” on page 84. 1.1.7 AVCC AVCC is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. Note that PC6..4 use digital supply voltage, VCC. 1.1.8 AREF AREF is the analog reference pin for the A/D Converter. 1.1.9 ADC7:6 (TQFP and QFN/MLF package only) In the TQFP and QFN/MLF package, ADC7:6 serve as analog inputs to the A/D converter. These pins are powered from the analog supply and serve as 10-bit ADC channels.5 2545T–AVR–05/11 ATmega48/88/168 2. Overview The Atmel ATmega48/88/168 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega48/88/168 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. 2.1 Block diagram Figure 2-1. Block diagram. The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting PORT D (8) PORT B (8) PORT C (7) USART 0 8bit T/C 2 8bit T/C 0 16bit T/C 1 A/D conv. Internal bandgap Analog comp. SPI TWI Flash SRAM EEPROM Watchdog oscillator Watchdog timer Oscillator circuits / clock generation Power supervision POR / BOD & RESET GND VCC PROGRAM LOGIC debugWIRE 2 GND AREF AVCC DATABUS PD[0..7] PB[0..7] PC[0..6] ADC[6..7] 6 RESET XTAL[1..2] CPU6 2545T–AVR–05/11 ATmega48/88/168 architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. The Atmel ATmega48/88/168 provides the following features: 4K/8K/16K bytes of In-System Programmable Flash with Read-While-Write capabilities, 256/512/512 bytes EEPROM, 512/1K/1K bytes SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with compare modes, internal and external interrupts, a serial programmable USART, a byte-oriented 2-wire Serial Interface, an SPI serial port, a 6-channel 10-bit ADC (8 channels in TQFP and QFN/MLF packages), a programmable Watchdog Timer with internal Oscillator, and five software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, USART, 2-wire Serial Interface, SPI port, and interrupt system to continue functioning. The Power-down mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next interrupt or hardware reset. In Power-save mode, the asynchronous timer continues to run, allowing the user to maintain a timer base while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules except asynchronous timer and ADC, to minimize switching noise during ADC conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low power consumption. Atmel offers the QTouch Library for embedding capacitive touch buttons, sliders and wheels functionality into AVR microcontrollers. The patented charge-transfer signal acquisition offers robust sensing and includes fully debounced reporting of touch keys and includes Adjacent Key Suppression® (AKS®) technology for unambigiuous detection of key events. The easy-to-use QTouch Suite toolchain allows you to explore, develop and debug your own touch applications. The device is manufactured using the Atmel high density non-volatile memory technology. The On-chip ISP Flash allows the program memory to be reprogrammed In-System through an SPI serial interface, by a conventional non-volatile memory programmer, or by an On-chip Boot program running on the AVR core. The Boot program can use any interface to download the application program in the Application Flash memory. Software in the Boot Flash section will continue to run while the Application Flash section is updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the Atmel ATmega48/88/168 is a powerful microcontroller that provides a highly flexible and cost effective solution to many embedded control applications. The ATmega48/88/168 AVR is supported with a full suite of program and system development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit Emulators, and Evaluation kits. 2.2 Comparison between Atmel ATmega48, Atmel ATmega88, and Atmel ATmega168 The ATmega48, ATmega88 and ATmega168 differ only in memory sizes, boot loader support, and interrupt vector sizes. Table 2-1 summarizes the different memory and interrupt vector sizes for the three devices. Table 2-1. Memory size summary. Device Flash EEPROM RAM Interrupt vector size ATmega48 4Kbytes 256Bytes 512Bytes 1 instruction word/vector ATmega88 8Kbytes 512Bytes 1Kbytes 1 instruction word/vector ATmega168 16Kbytes 512Bytes 1Kbytes 2 instruction words/vector7 2545T–AVR–05/11 ATmega48/88/168 ATmega88 and ATmega168 support a real Read-While-Write Self-Programming mechanism. There is a separate Boot Loader Section, and the SPM instruction can only execute from there. In ATmega48, there is no Read-While-Write support and no separate Boot Loader Section. The SPM instruction can execute from the entire Flash.8 2545T–AVR–05/11 ATmega48/88/168 3. Resources A comprehensive set of development tools, application notes and datasheets are available for download on http://www.atmel.com/avr. 4. Data retention Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C. 5. About code examples This documentation contains simple code examples that briefly show how to use various parts of the device. These code examples assume that the part specific header file is included before compilation. Be aware that not all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler dependent. Please confirm with the C compiler documentation for more details. For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with instructions that allow access to extended I/O. Typically “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”. 6. Capacitive touch sensing The Atmel QTouch Library provides a simple to use solution to realize touch sensitive interfaces on most Atmel AVR microcontrollers. The QTouch Library includes support for the QTouch and QMatrix acquisition methods. Touch sensing can be added to any application by linking the appropriate Atmel QTouch Library for the AVR Microcontroller. This is done by using a simple set of APIs to define the touch channels and sensors, and then calling the touch sensing API’s to retrieve the channel information and determine the touch sensor states. The QTouch Library is FREE and downloadable from the Atmel website at the following location: www.atmel.com/qtouchlibrary. For implementation details and other information, refer to the Atmel QTouch Library User Guide - also available for download from the Atmel website.9 2545T–AVR–05/11 ATmega48/88/168 7. AVR CPU core 7.1 Overview This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. 7.2 Architectural overview Figure 7-1. Block diagram of the AVR architecture. In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is In-System Reprogrammable Flash memory. Flash program memory Instruction register Instruction decoder Program counter Control lines 32 x 8 general purpose registrers ALU Status and control I/O lines EEPROM Data bus 8-bit Data SRAM Direct addressing Indirect addressing Interrupt unit SPI unit Watchdog timer Analog comparator I/O module 2 I/O module 1 I/O module n10 2545T–AVR–05/11 ATmega48/88/168 The fast-access Register File contains 32 × 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU) operation. In a typical ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling efficient address calculations. One of the these address pointers can also be used as an address pointer for look up tables in Flash program memory. These added function registers are the 16-bit X-register, Y-register, and Z-register, described later in this section. The ALU supports arithmetic and logic operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetic operation, the Status Register is updated to reflect information about the result of the operation. Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every program memory address contains a 16-bit or 32-bit instruction. Program Flash memory space is divided in two sections, the Boot Program section and the Application Program section. Both sections have dedicated Lock bits for write and read/write protection. The SPM instruction that writes into the Application Flash memory section must reside in the Boot Program section. During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the Reset routine (before subroutines or interrupts are executed). The Stack Pointer (SP) is read/write accessible in the I/O space. The data SRAM can easily be accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. A flexible interrupt module has its control registers in the I/O space with an additional Global Interrupt Enable bit in the Status Register. All interrupts have a separate Interrupt Vector in the Interrupt Vector table. The interrupts have priority in accordance with their Interrupt Vector position. The lower the Interrupt Vector address, the higher the priority. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, SPI, and other I/O functions. The I/O Memory can be accessed directly, or as the Data Space locations following those of the Register File, 0x20 - 0x5F. In addition, the ATmega48/88/168 has Extended I/O space from 0x60 - 0xFF in SRAM where only the ST/STS/STD and LD/LDS/LDD instructions can be used. 7.3 ALU – Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, arithmetic operations between general purpose registers or between a register and an immediate are executed. The ALU operations are divided into three main categories – arithmetic, logical, and bit-functions. Some implementations of the architecture also provide a powerful multiplier supporting both signed/unsigned multiplication and fractional format. See “Instruction set summary” on page 347 for a detailed description.11 2545T–AVR–05/11 ATmega48/88/168 7.4 Status register The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations. Note that the Status Register is updated after all ALU operations, as specified in the Instruction Set Reference. This will in many cases remove the need for using the dedicated compare instructions, resulting in faster and more compact code. The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an interrupt. This must be handled by software. 7.4.1 SREG – AVR Status Register The AVR Status Register – SREG – is defined as: • Bit 7 – I: Global interrupt enable The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the Global Interrupt Enable Register is cleared, none of the interrupts are enabled independent of the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-bit can also be set and cleared by the application with the SEI and CLI instructions, as described in the instruction set reference. • Bit 6 – T: Bit copy storage The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or destination for the operated bit. A bit from a register in the Register File can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the Register File by the BLD instruction. • Bit 5 – H: Half carry flag The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half Carry Is useful in BCD arithmetic. See the “Instruction Set Description” for detailed information. • Bit 4 – S: Sign bit, S = N ⊕ V The S-bit is always an exclusive or between the Negative Flag N and the Two’s Complement Overflow Flag V. See the “Instruction Set Description” for detailed information. • Bit 3 – V: Two’s complement overflow flag The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See the “Instruction Set Description” for detailed information. • Bit 2 – N: Negative flag The Negative Flag N indicates a negative result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. • Bit 1 – Z: Zero flag The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. Bit 7 6 5 4 3 2 1 0 0x3F (0x5F) I T H S V N Z C SREG Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 012 2545T–AVR–05/11 ATmega48/88/168 • Bit 0 – C: Carry flag The Carry Flag C indicates a carry in an arithmetic or logic operation. See the “Instruction Set Description” for detailed information. 7.5 General purpose register file The register file is optimized for the AVR enhanced RISC instruction set. In order to achieve the required performance and flexibility, the following input/output schemes are supported by the register file: • One 8-bit output operand and one 8-bit result input • Two 8-bit output operands and one 8-bit result input • Two 8-bit output operands and one 16-bit result input • One 16-bit output operand and one 16-bit result input Figure 7-2 shows the structure of the 32 general purpose working registers in the CPU. Figure 7-2. AVR CPU general purpose working registers. Most of the instructions operating on the register file have direct access to all registers, and most of them are single cycle instructions. As shown in Figure 7-2, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X-, Y- and Z-pointer registers can be set to index any register in the file. 7 0 Addr. R0 0x00 R1 0x01 R2 0x02 … R13 0x0D General R14 0x0E purpose R15 0x0F working R16 0x10 registers R17 0x11 … R26 0x1A X-register low byte R27 0x1B X-register high byte R28 0x1C Y-register low byte R29 0x1D Y-register high byte R30 0x1E Z-register low byte R31 0x1F Z-register high byte13 2545T–AVR–05/11 ATmega48/88/168 7.5.1 The X-register, Y-register, and Z-register The registers R26..R31 have some added functions to their general purpose usage. These registers are 16-bit address pointers for indirect addressing of the data space. The three indirect address registers X, Y, and Z are defined as described in Figure 7-3. Figure 7-3. The X-, Y-, and Z-registers. In the different addressing modes these address registers have functions as fixed displacement, automatic increment, and automatic decrement (see the instruction set reference for details). 7.6 Stack pointer The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses after interrupts and subroutine calls. The Stack Pointer Register always points to the top of the Stack. Note that the Stack is implemented as growing from higher memory locations to lower memory locations. This implies that a Stack PUSH command decreases the Stack Pointer. The Stack Pointer points to the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer must be set to point above 0x0100, preferably RAMEND. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when the return address is pushed onto the Stack with subroutine call or interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when data is popped from the Stack with return from subroutine RET or return from interrupt RETI. The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits actually used is implementation dependent. Note that the data space in some implementations of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register will not be present. 15 XH XL 0 X-register 7 07 0 R27 (0x1B) R26 (0x1A) 15 YH YL 0 Y-register 7 07 0 R29 (0x1D) R28 (0x1C) 15 ZH ZL 0 Z-register 70 7 0 R31 (0x1F) R30 (0x1E)14 2545T–AVR–05/11 ATmega48/88/168 7.6.1 SPH and SPL – Stack pointer high and stack pointer low register 7.7 Instruction execution timing This section describes the general access timing concepts for instruction execution. The AVR CPU is driven by the CPU clock clkCPU, directly generated from the selected clock source for the chip. No internal clock division is used. Figure 7-4 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access Register File concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. Figure 7-4. The parallel instruction fetches and instruction executions. Figure 7-5 shows the internal timing concept for the Register File. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. Figure 7-5. Single cycle ALU operation. Bit 15 14 13 12 11 10 9 8 0x3E (0x5E) SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 SPH 0x3D (0x5D) SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 SPL 76543210 Read/write R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Initial value RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND RAMEND clk 1st instruction fetch 1st instruction execute 2nd instruction fetch 2nd instruction execute 3rd instruction fetch 3rd instruction execute 4th instruction fetch T1 T2 T3 T4 CPU Total execution time Register operands fetch ALU operation execute Result write back T1 T2 T3 T4 clkCPU15 2545T–AVR–05/11 ATmega48/88/168 7.8 Reset and interrupt handling The AVR provides several different interrupt sources. These interrupts and the separate Reset Vector each have a separate program vector in the program memory space. All interrupts are assigned individual enable bits which must be written logic one together with the Global Interrupt Enable bit in the Status Register in order to enable the interrupt. Depending on the Program Counter value, interrupts may be automatically disabled when Boot Lock bits BLB02 or BLB12 are programmed. This feature improves software security. See the section “Memory programming” on page 285 for details. The lowest addresses in the program memory space are by default defined as the Reset and Interrupt Vectors. The complete list of vectors is shown in “Interrupts” on page 56. The list also determines the priority levels of the different interrupts. The lower the address the higher is the priority level. RESET has the highest priority, and next is INT0 – the External Interrupt Request 0. The Interrupt Vectors can be moved to the start of the Boot Flash section by setting the IVSEL bit in the MCU Control Register (MCUCR). Refer to “Interrupts” on page 56 for more information. The Reset Vector can also be moved to the start of the Boot Flash section by programming the BOOTRST Fuse, see “Boot loader support – Read-while-write self-programming, Atmel ATmega88 and Atmel ATmega168” on page 269. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a Return from Interrupt instruction – RETI – is executed. There are basically two types of interrupts. The first type is triggered by an event that sets the Interrupt Flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector in order to execute the interrupt handling routine, and hardware clears the corresponding Interrupt Flag. Interrupt Flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared, the Interrupt Flag will be set and remembered until the interrupt is enabled, or the flag is cleared by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable bit is cleared, the corresponding Interrupt Flag(s) will be set and remembered until the Global Interrupt Enable bit is set, and will then be executed by order of priority. The second type of interrupts will trigger as long as the interrupt condition is present. These interrupts do not necessarily have Interrupt Flags. If the interrupt condition disappears before the interrupt is enabled, the interrupt will not be triggered. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register is not automatically stored when entering an interrupt routine, nor restored when returning from an interrupt routine. This must be handled by software. When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled. No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the CLI instruction. The following example shows how this can be used to avoid interrupts during the timed EEPROM write sequence.16 2545T–AVR–05/11 ATmega48/88/168 When using the SEI instruction to enable interrupts, the instruction following SEI will be executed before any pending interrupts, as shown in this example. 7.8.1 Interrupt response time The interrupt execution response for all the enabled AVR interrupts is four clock cycles minimum. After four clock cycles the program vector address for the actual interrupt handling routine is executed. During this four clock cycle period, the Program Counter is pushed onto the Stack. The vector is normally a jump to the interrupt routine, and this jump takes three clock cycles. If an interrupt occurs during execution of a multi-cycle instruction, this instruction is completed before the interrupt is served. If an interrupt occurs when the MCU is in sleep mode, the interrupt execution response time is increased by four clock cycles. This increase comes in addition to the start-up time from the selected sleep mode. A return from an interrupt handling routine takes four clock cycles. During these four clock cycles, the Program Counter (two bytes) is popped back from the Stack, the Stack Pointer is incremented by two, and the I-bit in SREG is set. Assembly code example in r16, SREG ; store SREG value cli ; disable interrupts during timed sequence sbi EECR, EEMPE ; start EEPROM write sbi EECR, EEPE out SREG, r16 ; restore SREG value (I-bit) C code example char cSREG; cSREG = SREG; /* store SREG value */ /* disable interrupts during timed sequence */ _CLI(); EECR |= (1< xxx ... ... ... ... 22 0x015 ADC ADC conversion complete 23 0x016 EE READY EEPROM ready 24 0x017 ANALOG COMP Analog comparator 25 0x018 TWI 2-wire serial interface 26 0x019 SPM READY Store program memory ready Table 12-1. Reset and interrupt vectors in ATmega48. (Continued) Vector no. Program address Source Interrupt definition58 2545T–AVR–05/11 ATmega48/88/168 12.3 Interrupt vectors in Atmel ATmega88 Notes: 1. When the BOOTRST fuse is programmed, the device will jump to the boot loader address at reset, see “Boot loader support – Read-while-write self-programming, Atmel ATmega88 and Atmel ATmega168” on page 269. 2. When the IVSEL bit in MCUCR is set, interrupt vectors will be moved to the start of the boot flash section. The address of each Interrupt Vector will then be the address in this table added to the start address of the boot flash section. Table 12-3 on page 59 shows reset and interrupt vectors placement for the various combinations of BOOTRST and IVSEL settings. If the program never enables an interrupt source, the Interrupt Vectors are not used, and regular program code can be placed at these locations. This is also the case if the reset vector is in the application section while the interrupt vectors are in the boot section or vice versa. Table 12-2. Reset and interrupt vectors in ATmega88. Vector no. Program address(2) Source Interrupt definition 1 0x000(1) RESET External pin, power-on reset, brown-out reset and watchdog system reset 2 0x001 INT0 External interrupt request 0 3 0x002 INT1 External interrupt request 1 4 0x003 PCINT0 Pin change interrupt request 0 5 0x004 PCINT1 Pin change interrupt request 1 6 0x005 PCINT2 Pin change interrupt request 2 7 0x006 WDT Watchdog time-out interrupt 8 0x007 TIMER2 COMPA Timer/Counter2 compare match A 9 0x008 TIMER2 COMPB Timer/Counter2 compare match B 10 0x009 TIMER2 OVF Timer/Counter2 overflow 11 0x00A TIMER1 CAPT Timer/Counter1 capture event 12 0x00B TIMER1 COMPA Timer/Counter1 compare match A 13 0x00C TIMER1 COMPB Timer/Coutner1 compare match B 14 0x00D TIMER1 OVF Timer/Counter1 overflow 15 0x00E TIMER0 COMPA Timer/Counter0 compare match A 16 0x00F TIMER0 COMPB Timer/Counter0 compare match B 17 0x010 TIMER0 OVF Timer/Counter0 overflow 18 0x011 SPI, STC SPI serial transfer complete 19 0x012 USART, RX USART Rx complete 20 0x013 USART, UDRE USART, data register empty 21 0x014 USART, TX USART, Tx complete 22 0x015 ADC ADC conversion complete 23 0x016 EE READY EEPROM ready 24 0x017 ANALOG COMP Analog comparator 25 0x018 TWI 2-wire serial interface 26 0x019 SPM READY Store program memory ready59 2545T–AVR–05/11 ATmega48/88/168 Note: 1. The boot reset address is shown in Table 27-6 on page 281. For the BOOTRST Fuse “1” means unprogrammed while “0” means programmed. The most typical and general program setup for the reset and interrupt vector addresses in ATmega88 is: Address Labels Code Comments 0x000 rjmp RESET ; Reset Handler 0x001 rjmp EXT_INT0 ; IRQ0 Handler 0x002 rjmp EXT_INT1 ; IRQ1 Handler 0x003 rjmp PCINT0 ; PCINT0 Handler 0x004 rjmp PCINT1 ; PCINT1 Handler 0x005 rjmp PCINT2 ; PCINT2 Handler 0x006 rjmp WDT ; Watchdog Timer Handler 0x007 rjmp TIM2_COMPA ; Timer2 Compare A Handler 0X008 rjmp TIM2_COMPB ; Timer2 Compare B Handler 0x009 rjmp TIM2_OVF ; Timer2 Overflow Handler 0x00A rjmp TIM1_CAPT ; Timer1 Capture Handler 0x00B rjmp TIM1_COMPA ; Timer1 Compare A Handler 0x00C rjmp TIM1_COMPB ; Timer1 Compare B Handler 0x00D rjmp TIM1_OVF ; Timer1 Overflow Handler 0x00E rjmp TIM0_COMPA ; Timer0 Compare A Handler 0x00F rjmp TIM0_COMPB ; Timer0 Compare B Handler 0x010 rjmp TIM0_OVF ; Timer0 Overflow Handler 0x011 rjmp SPI_STC ; SPI Transfer Complete Handler 0x012 rjmp USART_RXC ; USART, RX Complete Handler 0x013 rjmp USART_UDRE ; USART, UDR Empty Handler 0x014 rjmp USART_TXC ; USART, TX Complete Handler 0x015 rjmp ADC ; ADC Conversion Complete Handler 0x016 rjmp EE_RDY ; EEPROM Ready Handler 0x017 rjmp ANA_COMP ; Analog Comparator Handler 0x018 rjmp TWI ; 2-wire Serial Interface Handler 0x019 rjmp SPM_RDY ; Store Program Memory Ready Handler ; 0x01ARESET: ldi r16, high(RAMEND); Main program start 0x01B out SPH,r16 ; Set Stack Pointer to top of RAM 0x01C ldi r16, low(RAMEND) 0x01D out SPL,r16 0x01E sei ; Enable interrupts 0x01F xxx Table 12-3. Reset and interrupt vectors placement in Atmel ATmega88(1). BOOTRST IVSEL Reset address Interrupt vectors start address 1 0 0x000 0x001 1 1 0x000 Boot reset address + 0x001 0 0 Boot reset address 0x001 0 1 Boot reset address Boot reset address + 0x00160 2545T–AVR–05/11 ATmega48/88/168 When the BOOTRST fuse is unprogrammed, the boot section size set to 2Kbytes and the IVSEL bit in the MCUCR register is set before any interrupts are enabled, the most typical and general program setup for the reset and interrupt vector addresses in Atmel ATmega88 is: Address Labels Code Comments 0x000 RESET: ldi r16,high(RAMEND); Main program start 0x001 out SPH,r16 ; Set Stack Pointer to top of RAM 0x002 ldi r16,low(RAMEND) 0x003 out SPL,r16 0x004 sei ; Enable interrupts 0x005 xxx ; .org 0xC01 0xC01 rjmp EXT_INT0 ; IRQ0 Handler 0xC02 rjmp EXT_INT1 ; IRQ1 Handler ... ... ... ; 0xC19 rjmp SPM_RDY ; Store Program Memory Ready Handler When the BOOTRST fuse is programmed and the boot section size set to 2Kbytes, the most typical and general program setup for the reset and interrupt vector addresses in ATmega88 is: Address Labels Code Comments .org 0x001 0x001 rjmp EXT_INT0 ; IRQ0 Handler 0x002 rjmp EXT_INT1 ; IRQ1 Handler ... ... ... ; 0x019 rjmp SPM_RDY ; Store Program Memory Ready Handler ; .org 0xC00 0xC00 RESET: ldi r16,high(RAMEND); Main program start 0xC01 out SPH,r16 ; Set Stack Pointer to top of RAM 0xC02 ldi r16,low(RAMEND) 0xC03 out SPL,r16 0xC04 sei ; Enable interrupts 0xC05 xxx When the BOOTRST fuse is programmed, the boot section size set to 2Kbytes and the IVSEL bit in the MCUCR register is set before any interrupts are enabled, the most typical and general program setup for the reset and interrupt vector addresses in ATmega88 is: Address Labels Code Comments ; .org 0xC00 0xC00 rjmp RESET ; Reset handler 0xC01 rjmp EXT_INT0 ; IRQ0 Handler 0xC02 rjmp EXT_INT1 ; IRQ1 Handler ... ... ... ; 0xC19 rjmp SPM_RDY ; Store Program Memory Ready Handler ; 0xC1A RESET: ldi r16,high(RAMEND); Main program start 0xC1B out SPH,r16 ; Set Stack Pointer to top of RAM61 2545T–AVR–05/11 ATmega48/88/168 0xC1C ldi r16,low(RAMEND) 0xC1D out SPL,r16 0xC1E sei ; Enable interrupts 0xC1F xxx 12.4 Interrupt vectors in Atmel ATmega168 Notes: 1. When the BOOTRST fuse is programmed, the device will jump to the boot loader address at reset, see “Boot loader support – Read-while-write self-programming, Atmel ATmega88 and Atmel ATmega168” on page 269. 2. When the IVSEL bit in MCUCR is set, interrupt vectors will be moved to the start of the boot flash section. The address of each Interrupt Vector will then be the address in this table added to the start address of the boot flash section. Table 12-4. Reset and interrupt vectors in ATmega168. Vector no. Program address(2) Source Interrupt definition 1 0x0000(1) RESET External pin, power-on reset, brown-out reset and watchdog system reset 2 0x0002 INT0 External interrupt request 0 3 0x0004 INT1 External interrupt request 1 4 0x0006 PCINT0 Pin change interrupt request 0 5 0x0008 PCINT1 Pin change interrupt request 1 6 0x000A PCINT2 Pin change interrupt request 2 7 0x000C WDT Watchdog time-out interrupt 8 0x000E TIMER2 COMPA Timer/Counter2 compare match A 9 0x0010 TIMER2 COMPB Timer/Counter2 compare match B 10 0x0012 TIMER2 OVF Timer/Counter2 overflow 11 0x0014 TIMER1 CAPT Timer/Counter1 capture event 12 0x0016 TIMER1 COMPA Timer/Counter1 compare match A 13 0x0018 TIMER1 COMPB Timer/Coutner1 compare match B 14 0x001A TIMER1 OVF Timer/Counter1 overflow 15 0x001C TIMER0 COMPA Timer/Counter0 compare match A 16 0x001E TIMER0 COMPB Timer/Counter0 compare match B 17 0x0020 TIMER0 OVF Timer/Counter0 overflow 18 0x0022 SPI, STC SPI serial transfer complete 19 0x0024 USART, RX USART Rx complete 20 0x0026 USART, UDRE USART, data register empty 21 0x0028 USART, TX USART, Tx complete 22 0x002A ADC ADC conversion complete 23 0x002C EE READY EEPROM ready 24 0x002E ANALOG COMP Analog comparator 25 0x0030 TWI 2-wire serial interface 26 0x0032 SPM READY Store program memory ready62 2545T–AVR–05/11 ATmega48/88/168 Table 12-5 shows reset and interrupt vectors placement for the various combinations of BOOTRST and IVSEL settings. If the program never enables an interrupt source, the interrupt vectors are not used, and regular program code can be placed at these locations. This is also the case if the reset vector is in the application section while the interrupt vectors are in the boot section or vice versa. Note: 1. The boot reset address is shown in Table 27-6 on page 281. For the BOOTRST fuse “1” means unprogrammed while “0” means programmed. The most typical and general program setup for the reset and interrupt vector addresses in ATmega168 is: Address Labels Code Comments 0x0000 jmp RESET ; Reset Handler 0x0002 jmp EXT_INT0 ; IRQ0 Handler 0x0004 jmp EXT_INT1 ; IRQ1 Handler 0x0006 jmp PCINT0 ; PCINT0 Handler 0x0008 jmp PCINT1 ; PCINT1 Handler 0x000A jmp PCINT2 ; PCINT2 Handler 0x000C jmp WDT ; Watchdog Timer Handler 0x000E jmp TIM2_COMPA ; Timer2 Compare A Handler 0x0010 jmp TIM2_COMPB ; Timer2 Compare B Handler 0x0012 jmp TIM2_OVF ; Timer2 Overflow Handler 0x0014 jmp TIM1_CAPT ; Timer1 Capture Handler 0x0016 jmp TIM1_COMPA ; Timer1 Compare A Handler 0x0018 jmp TIM1_COMPB ; Timer1 Compare B Handler 0x001A jmp TIM1_OVF ; Timer1 Overflow Handler 0x001C jmp TIM0_COMPA ; Timer0 Compare A Handler 0x001E jmp TIM0_COMPB ; Timer0 Compare B Handler 0x0020 jmp TIM0_OVF ; Timer0 Overflow Handler 0x0022 jmp SPI_STC ; SPI Transfer Complete Handler 0x0024 jmp USART_RXC ; USART, RX Complete Handler 0x0026 jmp USART_UDRE ; USART, UDR Empty Handler 0x0028 jmp USART_TXC ; USART, TX Complete Handler 0x002A jmp ADC ; ADC Conversion Complete Handler 0x002C jmp EE_RDY ; EEPROM Ready Handler 0x002E jmp ANA_COMP ; Analog Comparator Handler 0x0030 jmp TWI ; 2-wire Serial Interface Handler 0x0032 jmp SPM_RDY ; Store Program Memory Ready Handler ; 0x0033RESET: ldi r16, high(RAMEND); Main program start Table 12-5. Reset and interrupt vectors placement in Atmel ATmega168(1). BOOTRST IVSEL Reset address Interrupt vectors start address 1 0 0x000 0x001 1 1 0x000 Boot reset address + 0x0002 0 0 Boot reset address 0x001 0 1 Boot reset address Boot reset address + 0x000263 2545T–AVR–05/11 ATmega48/88/168 0x0034 out SPH,r16 ; Set Stack Pointer to top of RAM 0x0035 ldi r16, low(RAMEND) 0x0036 out SPL,r16 0x0037 sei ; Enable interrupts 0x0038 xxx ... ... ... ... When the BOOTRST fuse is unprogrammed, the boot section size set to 2Kbytes and the IVSEL bit in the MCUCR Register is set before any interrupts are enabled, the most typical and general program setup for the reset and interrupt vector addresses in Atmel ATmega168 is: Address Labels Code Comments 0x0000 RESET: ldi r16,high(RAMEND); Main program start 0x0001 out SPH,r16 ; Set Stack Pointer to top of RAM 0x0002 ldi r16,low(RAMEND) 0x0003 out SPL,r16 0x0004 sei ; Enable interrupts 0x0005 xxx ; .org 0xC02 0x1C02 jmp EXT_INT0 ; IRQ0 Handler 0x1C04 jmp EXT_INT1 ; IRQ1 Handler ... ... ... ; 0x1C32 jmp SPM_RDY ; Store Program Memory Ready Handler When the BOOTRST fuse is programmed and the boot section size set to 2Kbytes, the most typical and general program setup for the reset and interrupt vector addresses in ATmega168 is: Address Labels Code Comments .org 0x0002 0x0002 jmp EXT_INT0 ; IRQ0 Handler 0x0004 jmp EXT_INT1 ; IRQ1 Handler ... ... ... ; 0x0032 jmp SPM_RDY ; Store Program Memory Ready Handler ; .org 0x1C00 0x1C00 RESET: ldi r16,high(RAMEND); Main program start 0x1C01 out SPH,r16 ; Set Stack Pointer to top of RAM 0x1C02 ldi r16,low(RAMEND) 0x1C03 out SPL,r16 0x1C04 sei ; Enable interrupts 0x1C05 xxx When the BOOTRST fuse is programmed, the boot section size set to 2Kbytes and the IVSEL bit in the MCUCR register is set before any interrupts are enabled, the most typical and general program setup for the reset and interrupt vector addresses in ATmega168 is:64 2545T–AVR–05/11 ATmega48/88/168 Address Labels Code Comments ; .org 0x1C00 0x1C00 jmp RESET ; Reset handler 0x1C02 jmp EXT_INT0 ; IRQ0 Handler 0x1C04 jmp EXT_INT1 ; IRQ1 Handler ... ... ... ; 0x1C32 jmp SPM_RDY ; Store Program Memory Ready Handler ; 0x1C33 RESET: ldi r16,high(RAMEND); Main program start 0x1C34 out SPH,r16 ; Set Stack Pointer to top of RAM 0x1C35 ldi r16,low(RAMEND) 0x1C36 out SPL,r16 0x1C37 sei ; Enable interrupts 0x1C38 xxx 12.4.1 Moving interrupts between application and boot space, Atmel ATmega88 and Atmel ATmega168 The MCU control register controls the placement of the interrupt vector table. 12.5 Register description 12.5.1 MCUCR – MCU control register • Bit 1 – IVSEL: Interrupt vector select When the IVSEL bit is cleared (zero), the interrupt vectors are placed at the start of the flash memory. When this bit is set (one), the interrupt vectors are moved to the beginning of the boot loader section of the flash. The actual address of the start of the boot flash section is determined by the BOOTSZ fuses. Refer to the section “Boot loader support – Read-while-write self-programming, Atmel ATmega88 and Atmel ATmega168” on page 269 for details. To avoid unintentional changes of interrupt vector tables, a special write procedure must be followed to change the IVSEL bit: a. Write the interrupt vector change enable (IVCE) bit to one. b. Within four cycles, write the desired value to IVSEL while writing a zero to IVCE. Interrupts will automatically be disabled while this sequence is executed. Interrupts are disabled in the cycle IVCE is set, and they remain disabled until after the instruction following the write to IVSEL. If IVSEL is not written, interrupts remain disabled for four cycles. The I-bit in the status register is unaffected by the automatic disabling. Note: If interrupt vectors are placed in the boot loader section and boot lock bit BLB02 is programmed, interrupts are disabled while executing from the Application section. If interrupt vectors are placed in the Application section and boot lock bit BLB12 is programmed, interrupts are disabled while executing from the Boot Loader section. Refer to the section “Boot loader support – Read-whilewrite self-programming, Atmel ATmega88 and Atmel ATmega168” on page 269 for details on Boot Lock bits. This bit is not available in Atmel ATmega48. Bit 7 6 5 4 3 2 1 0 0x35 (0x55) – – – PUD – – IVSEL IVCE MCUCR Read/write R R R R/W R R R/W R/W Initial value 0 0 0 0 0 0 0 065 2545T–AVR–05/11 ATmega48/88/168 • Bit 0 – IVCE: Interrupt vector change enable The IVCE bit must be written to logic one to enable change of the IVSEL bit. IVCE is cleared by hardware four cycles after it is written or when IVSEL is written. Setting the IVCE bit will disable interrupts, as explained in the IVSEL description above. See code example below. This bit is not available in Atmel ATmega48. Assembly code example Move_interrupts: ; Get MCUCR in r16, MCUCR mov r17, r16 ; Enable change of Interrupt Vectors ori r16, (1< CSn2:0 > 1). The number of system clock cycles from when the timer is enabled to the first count occurs can be from 1 to N+1 system clock cycles, where N equals the prescaler divisor (8, 64, 256, or 1024). It is possible to use the prescaler reset for synchronizing the Timer/Counter to program execution. However, care must be taken if the other Timer/Counter that shares the same prescaler also uses prescaling. A prescaler reset will affect the prescaler period for all Timer/Counters it is connected to. 17.0.3 External clock source An external clock source applied to the T1/T0 pin can be used as Timer/Counter clock (clkT1/clkT0). The T1/T0 pin is sampled once every system clock cycle by the pin synchronization logic. The synchronized (sampled) signal is then passed through the edge detector. Figure 17-1 shows a functional equivalent block diagram of the T1/T0 synchronization and edge detector logic. The registers are clocked at the positive edge of the internal system clock (clkI/O). The latch is transparent in the high period of the internal system clock. The edge detector generates one clkT1/clkT0 pulse for each positive (CSn2:0 = 7) or negative (CSn2:0 = 6) edge it detects. Figure 17-1. T1/T0 pin sampling. The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles from an edge has been applied to the T1/T0 pin to the counter is updated. Tn_sync (to clock select logic) Synchronization Edge detector D Q D Q LE Tn D Q clkI/O138 2545T–AVR–05/11 ATmega48/88/168 Enabling and disabling of the clock input must be done when T1/T0 has been stable for at least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated. Each half period of the external clock applied must be longer than one system clock cycle to ensure correct sampling. The external clock must be guaranteed to have less than half the system clock frequency (fExtClk < fclk_I/O/2) given a 50/50% duty cycle. Since the edge detector uses sampling, the maximum frequency of an external clock it can detect is half the sampling frequency (Nyquist sampling theorem). However, due to variation of the system clock frequency and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is recommended that maximum frequency of an external clock source is less than fclk_I/O/2.5. An external clock source can not be prescaled. Figure 17-2. Prescaler for timer/counter0 and timer/counter1(1). Note: 1. The synchronization logic on the input pins (T1/T0) is shown in Figure 17-1 on page 137. PSRSYNC Clear clkT1 clkT0 T1 T0 clkI/O Synchronization Synchronization139 2545T–AVR–05/11 ATmega48/88/168 17.1 Register description 17.1.1 GTCCR – General timer/counter control register • Bit 7 – TSM: Timer/counter synchronization mode Writing the TSM bit to one activates the Timer/Counter Synchronization mode. In this mode, the value that is written to the PSRASY and PSRSYNC bits is kept, hence keeping the corresponding prescaler reset signals asserted. This ensures that the corresponding Timer/Counters are halted and can be configured to the same value without the risk of one of them advancing during configuration. When the TSM bit is written to zero, the PSRASY and PSRSYNC bits are cleared by hardware, and the Timer/Counters start counting simultaneously. • Bit 0 – PSRSYNC: Prescaler reset When this bit is one, Timer/Counter1 and Timer/Counter0 prescaler will be Reset. This bit is normally cleared immediately by hardware, except if the TSM bit is set. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler and a reset of this prescaler will affect both timers. Bit 7 6 5 4 3 2 1 0 0x23 (0x43) TSM – – – – – PSRASY PSRSYNC GTCCR Read/write R/W R R R R R R/W R/W Initial value 0 0 0 0 0 0 0 0140 2545T–AVR–05/11 ATmega48/88/168 18. 8-bit Timer/Counter2 with PWM and asynchronous operation 18.1 Features • Single channel counter • Clear timer on compare match (auto reload) • Glitch-free, phase correct pulse width modulator (PWM) • Frequency generator • 10-bit clock prescaler • Overflow and compare match interrupt sources (TOV2, OCF2A and OCF2B) • Allows clocking from external 32kHz watch crystal independent of the I/O clock 18.2 Overview Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 18-1. For the actual placement of I/O pins, refer to “Pinout Atmel ATmega48/88/168.” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “Register description” on page 153. The PRTIM2 bit in “Minimizing power consumption” on page 41 must be written to zero to enable Timer/Counter2 module. Figure 18-1. 8-bit timer/counter block diagram. Clock select Timer/counter DATA BUS OCRnA OCRnB = = TCNTn Waveform generation Waveform generation OCnA OCnB = Fixed TOP value Control logic = 0 TOP BOTTOM Count Clear Direction TOVn (Int.req.) OCnA (Int.req.) OCnB (Int.req.) TCCRnA TCCRnB Tn Edge detector (From prescaler) clkTn141 2545T–AVR–05/11 ATmega48/88/168 18.2.1 Registers The Timer/Counter (TCNT2) and Output Compare Register (OCR2A and OCR2B) are 8-bit registers. Interrupt request (shorten as Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFR2). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK2). TIFR2 and TIMSK2 are not shown in the figure. The Timer/Counter can be clocked internally, via the prescaler, or asynchronously clocked from the TOSC1/2 pins, as detailed later in this section. The asynchronous operation is controlled by the Asynchronous Status Register (ASSR). The Clock Select logic block controls which clock source he Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the Clock Select logic is referred to as the timer clock (clkT2). The double buffered Output Compare Register (OCR2A and OCR2B) are compared with the Timer/Counter value at all times. The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pins (OC2A and OC2B). See “Output compare unit” on page 142. for details. The compare match event will also set the Compare Flag (OCF2A or OCF2B) which can be used to generate an Output Compare interrupt request. 18.2.2 Definitions Many register and bit references in this document are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 2. However, when using the register or bit defines in a program, the precise form must be used, that is, TCNT2 for accessing Timer/Counter2 counter value and so on. The definitions in Table 18-1 are also used extensively throughout the section. 18.3 Timer/counter clock sources The Timer/Counter can be clocked by an internal synchronous or an external asynchronous clock source. The clock source clkT2 is by default equal to the MCU clock, clkI/O. When the AS2 bit in the ASSR Register is written to logic one, the clock source is taken from the Timer/Counter Oscillator connected to TOSC1 and TOSC2. For details on asynchronous operation, see “ASSR – Asynchronous status register” on page 159. For details on clock sources and prescaler, see “Timer/counter prescaler” on page 152. 18.4 Counter unit The main part of the 8-bit Timer/Counter is the programmable bi-directional counter unit. Figure 18-2 on page 142 shows a block diagram of the counter and its surrounding environment. Table 18-1. Definitions. BOTTOM The counter reaches the BOTTOM when it becomes zero (0x00). MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255). TOP The counter reaches the TOP when it becomes equal to the highest value in the count sequence. The TOP value can be assigned to be the fixed value 0xFF (MAX) or the value stored in the OCR2A Register. The assignment is dependent on the mode of operation.142 2545T–AVR–05/11 ATmega48/88/168 Figure 18-2. Counter unit block diagram. Signal description (internal signals): count Increment or decrement TCNT2 by 1. direction Selects between increment and decrement. clear Clear TCNT2 (set all bits to zero). clkTn Timer/Counter clock, referred to as clkT2 in the following. top Signalizes that TCNT2 has reached maximum value. bottom Signalizes that TCNT2 has reached minimum value (zero). Depending on the mode of operation used, the counter is cleared, incremented, or decremented at each timer clock (clkT2). clkT2 can be generated from an external or internal clock source, selected by the Clock Select bits (CS22:0). When no clock source is selected (CS22:0 = 0) the timer is stopped. However, the TCNT2 value can be accessed by the CPU, regardless of whether clkT2 is present or not. A CPU write overrides (has priority over) all counter clear or count operations. The counting sequence is determined by the setting of the WGM21 and WGM20 bits located in the Timer/Counter Control Register (TCCR2A) and the WGM22 located in the Timer/Counter Control Register B (TCCR2B). There are close connections between how the counter behaves (counts) and how waveforms are generated on the Output Compare outputs OC2A and OC2B. For more details about advanced counting sequences and waveform generation, see “Modes of operation” on page 145. The Timer/Counter Overflow Flag (TOV2) is set according to the mode of operation selected by the WGM22:0 bits. TOV2 can be used for generating a CPU interrupt. 18.5 Output compare unit The 8-bit comparator continuously compares TCNT2 with the Output Compare Register (OCR2A and OCR2B). Whenever TCNT2 equals OCR2A or OCR2B, the comparator signals a match. A match will set the Output Compare Flag (OCF2A or OCF2B) at the next timer clock cycle. If the corresponding interrupt is enabled, the Output Compare Flag generates an Output Compare interrupt. The Output Compare Flag is automatically cleared when the interrupt is executed. Alternatively, the Output Compare Flag can be cleared by software by writing a logical one to its I/O bit location. The Waveform Generator uses the match signal to generate an output according to operating mode set by the WGM22:0 bits and Compare Output mode (COM2x1:0) bits. The max and bottom signals are used by the Waveform Generator for handling the special cases of the extreme values in some modes of operation (“Modes of operation” on page 145). Figure 18-3 on page 143 shows a block diagram of the Output Compare unit. DATA BUS TCNTn Control logic count TOVn (Int.req.) bottom top direction clear TOSC1 T/C oscillator TOSC2 Prescaler clkI/O clk Tn143 2545T–AVR–05/11 ATmega48/88/168 Figure 18-3. Output compare unit, block diagram. The OCR2x Register is double buffered when using any of the Pulse Width Modulation (PWM) modes. For the Normal and Clear Timer on Compare (CTC) modes of operation, the double buffering is disabled. The double buffering synchronizes the update of the OCR2x Compare Register to either top or bottom of the counting sequence. The synchronization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free. The OCR2x Register access may seem complex, but this is not case. When the double buffering is enabled, the CPU has access to the OCR2x Buffer Register, and if double buffering is disabled the CPU will access the OCR2x directly. 18.5.1 Force output compare In non-PWM waveform generation modes, the match output of the comparator can be forced by writing a one to the Force Output Compare (FOC2x) bit. Forcing compare match will not set the OCF2x Flag or reload/clear the timer, but the OC2x pin will be updated as if a real compare match had occurred (the COM2x1:0 bits settings define whether the OC2x pin is set, cleared or toggled). 18.5.2 Compare match blocking by TCNT2 write All CPU write operations to the TCNT2 Register will block any compare match that occurs in the next timer clock cycle, even when the timer is stopped. This feature allows OCR2x to be initialized to the same value as TCNT2 without triggering an interrupt when the Timer/Counter clock is enabled. 18.5.3 Using the output compare unit Since writing TCNT2 in any mode of operation will block all compare matches for one timer clock cycle, there are risks involved when changing TCNT2 when using the Output Compare channel, independently of whether the Timer/Counter is running or not. If the value written to TCNT2 equals the OCR2x value, the compare match will be missed, resulting in incorrect waveform generation. Similarly, do not write the TCNT2 value equal to BOTTOM when the counter is downcounting. OCFnx (int.req.) = (8-bit comparator) OCRnx OCnx DATA BUS TCNTn WGMn1:0 Waveform generator top FOCn COMnX1:0 bottom144 2545T–AVR–05/11 ATmega48/88/168 The setup of the OC2x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC2x value is to use the Force Output Compare (FOC2x) strobe bit in Normal mode. The OC2x Register keeps its value even when changing between Waveform Generation modes. Be aware that the COM2x1:0 bits are not double buffered together with the compare value. Changing the COM2x1:0 bits will take effect immediately. 18.6 Compare match output unit The Compare Output mode (COM2x1:0) bits have two functions. The Waveform Generator uses the COM2x1:0 bits for defining the Output Compare (OC2x) state at the next compare match. Also, the COM2x1:0 bits control the OC2x pin output source. Figure 18-4 shows a simplified schematic of the logic affected by the COM2x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM2x1:0 bits are shown. When referring to the OC2x state, the reference is for the internal OC2x Register, not the OC2x pin. Figure 18-4. Compare match output unit, schematic. The general I/O port function is overridden by the Output Compare (OC2x) from the Waveform Generator if either of the COM2x1:0 bits are set. However, the OC2x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC2x pin (DDR_OC2x) must be set as output before the OC2x value is visible on the pin. The port override function is independent of the Waveform Generation mode. The design of the Output Compare pin logic allows initialization of the OC2x state before the output is enabled. Note that some COM2x1:0 bit settings are reserved for certain modes of operation. See “Register description” on page 153. PORT DDR D Q D Q OCnx OCnx pin D Q Waveform generator COMnx1 COMnx0 0 1 DATA BUS FOCnx clkI/O145 2545T–AVR–05/11 ATmega48/88/168 18.6.1 Compare output mode and waveform generation The Waveform Generator uses the COM2x1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM2x1:0 = 0 tells the Waveform Generator that no action on the OC2x Register is to be performed on the next compare match. For compare output actions in the non-PWM modes refer to Table 18-5 on page 154. For fast PWM mode, refer to Table 18-6 on page 155, and for phase correct PWM refer to Table 18-7 on page 155. A change of the COM2x1:0 bits state will have effect at the first compare match after the bits are written. For non-PWM modes, the action can be forced to have immediate effect by using the FOC2x strobe bits. 18.7 Modes of operation The mode of operation, that is, the behavior of the Timer/Counter and the Output Compare pins, is defined by the combination of the Waveform Generation mode (WGM22:0) and Compare Output mode (COM2x1:0) bits. The Compare Output mode bits do not affect the counting sequence, while the Waveform Generation mode bits do. The COM2x1:0 bits control whether the PWM output generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes the COM2x1:0 bits control whether the output should be set, cleared, or toggled at a compare match (See “Compare match output unit” on page 144.). For detailed timing information refer to “Timer/counter timing diagrams” on page 149. 18.7.1 Normal mode The simplest mode of operation is the Normal mode (WGM22:0 = 0). In this mode the counting direction is always up (incrementing), and no counter clear is performed. The counter simply overruns when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV2) will be set in the same timer clock cycle as the TCNT2 becomes zero. The TOV2 Flag in this case behaves like a ninth bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV2 Flag, the timer resolution can be increased by software. There are no special cases to consider in the Normal mode, a new counter value can be written anytime. The Output Compare unit can be used to generate interrupts at some given time. Using the Output Compare to generate waveforms in Normal mode is not recommended, since this will occupy too much of the CPU time. 18.7.2 Clear timer on compare match (CTC) mode In Clear Timer on Compare or CTC mode (WGM22:0 = 2), the OCR2A Register is used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value (TCNT2) matches the OCR2A. The OCR2A defines the top value for the counter, hence also its resolution. This mode allows greater control of the compare match output frequency. It also simplifies the operation of counting external events. The timing diagram for the CTC mode is shown in Figure 18-5 on page 146. The counter value (TCNT2) increases until a compare match occurs between TCNT2 and OCR2A, and then counter (TCNT2) is cleared.146 2545T–AVR–05/11 ATmega48/88/168 Figure 18-5. CTC mode, timing diagram. An interrupt can be generated each time the counter value reaches the TOP value by using the OCF2A Flag. If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value. However, changing TOP to a value close to BOTTOM when the counter is running with none or a low prescaler value must be done with care since the CTC mode does not have the double buffering feature. If the new value written to OCR2A is lower than the current value of TCNT2, the counter will miss the compare match. The counter will then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the compare match can occur. For generating a waveform output in CTC mode, the OC2A output can be set to toggle its logical level on each compare match by setting the Compare Output mode bits to toggle mode (COM2A1:0 = 1). The OC2A value will not be visible on the port pin unless the data direction for the pin is set to output. The waveform generated will have a maximum frequency of fOC2A = fclk_I/O/2 when OCR2A is set to zero (0x00). The waveform frequency is defined by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). As for the normal mode of operation, the TOV2 Flag is set in the same timer clock cycle that the counter counts from MAX to 0x00. 18.7.3 Fast PWM mode The fast Pulse Width Modulation or fast PWM mode (WGM22:0 = 3 or 7) provides a high frequency PWM waveform generation option. The fast PWM differs from the other PWM option by its single-slope operation. The counter counts from BOTTOM to TOP then restarts from BOTTOM. TOP is defined as 0xFF when WGM2:0 = 3, and OCR2A when MGM2:0 = 7. In noninverting Compare Output mode, the Output Compare (OC2x) is cleared on the compare match between TCNT2 and OCR2x, and set at BOTTOM. In inverting Compare Output mode, the output is set on compare match and cleared at BOTTOM. Due to the single-slope operation, the operating frequency of the fast PWM mode can be twice as high as the phase correct PWM mode that uses dual-slope operation. This high frequency makes the fast PWM mode well suited for power regulation, rectification, and DAC applications. High frequency allows physically small sized external components (coils, capacitors), and therefore reduces total system cost. TCNTn OCnx (toggle) OCnx interrupt flag set Period 1 2 3 4 (COMnx1:0 = 1) f OCnx f clk_I/O 2 ⋅ ⋅ N ( ) 1 + OCRnx = -------------------------------------------------147 2545T–AVR–05/11 ATmega48/88/168 In fast PWM mode, the counter is incremented until the counter value matches the TOP value. The counter is then cleared at the following timer clock cycle. The timing diagram for the fast PWM mode is shown in Figure 18-6. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the single-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2x and TCNT2. Figure 18-6. Fast PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches TOP. If the interrupt is enabled, the interrupt handler routine can be used for updating the compare value. In fast PWM mode, the compare unit allows generation of PWM waveforms on the OC2x pin. Setting the COM2x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting the COM2x1:0 to three. TOP is defined as 0xFF when WGM2:0 = 3, and OCR2A when MGM2:0 = 7. (See Table 18-3 on page 154). The actual OC2x value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by setting (or clearing) the OC2x Register at the compare match between OCR2x and TCNT2, and clearing (or setting) the OC2x Register at the timer clock cycle the counter is cleared (changes from TOP to BOTTOM). The PWM frequency for the output can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2A Register represent special cases when generating a PWM waveform output in the fast PWM mode. If the OCR2A is set equal to BOTTOM, the output will be a narrow spike for each MAX+1 timer clock cycle. Setting the OCR2A equal to MAX will result in a constantly high or low output (depending on the polarity of the output set by the COM2A1:0 bits.) A frequency (with 50% duty cycle) waveform output in fast PWM mode can be achieved by setting OC2x to toggle its logical level on each compare match (COM2x1:0 = 1). The waveform TCNTn OCRnx update and TOVn interrupt flag set Period 1 2 3 OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx interrupt flag set 4 5 6 7 f OCnxPWM f clk_I/O N ⋅ 256 = ------------------148 2545T–AVR–05/11 ATmega48/88/168 generated will have a maximum frequency of foc2 = fclk_I/O/2 when OCR2A is set to zero. This feature is similar to the OC2A toggle in CTC mode, except the double buffer feature of the Output Compare unit is enabled in the fast PWM mode. 18.7.4 Phase correct PWM mode The phase correct PWM mode (WGM22:0 = 1 or 5) provides a high resolution phase correct PWM waveform generation option. The phase correct PWM mode is based on a dual-slope operation. The counter counts repeatedly from BOTTOM to TOP and then from TOP to BOTTOM. TOP is defined as 0xFF when WGM2:0 = 3, and OCR2A when MGM2:0 = 7. In noninverting Compare Output mode, the Output Compare (OC2x) is cleared on the compare match between TCNT2 and OCR2x while upcounting, and set on the compare match while downcounting. In inverting Output Compare mode, the operation is inverted. The dual-slope operation has lower maximum operation frequency than single slope operation. However, due to the symmetric feature of the dual-slope PWM modes, these modes are preferred for motor control applications. In phase correct PWM mode the counter is incremented until the counter value matches TOP. When the counter reaches TOP, it changes the count direction. The TCNT2 value will be equal to TOP for one timer clock cycle. The timing diagram for the phase correct PWM mode is shown on Figure 18-7. The TCNT2 value is in the timing diagram shown as a histogram for illustrating the dual-slope operation. The diagram includes non-inverted and inverted PWM outputs. The small horizontal line marks on the TCNT2 slopes represent compare matches between OCR2x and TCNT2. Figure 18-7. Phase correct PWM mode, timing diagram. The Timer/Counter Overflow Flag (TOV2) is set each time the counter reaches BOTTOM. The Interrupt Flag can be used to generate an interrupt each time the counter reaches the BOTTOM value. In phase correct PWM mode, the compare unit allows generation of PWM waveforms on the OC2x pin. Setting the COM2x1:0 bits to two will produce a non-inverted PWM. An inverted PWM TOVn interrupt flag set OCnx interrupt flag set 1 2 3 TCNTn Period OCnx OCnx (COMnx1:0 = 2) (COMnx1:0 = 3) OCRnx update149 2545T–AVR–05/11 ATmega48/88/168 output can be generated by setting the COM2x1:0 to three. TOP is defined as 0xFF when WGM2:0 = 3, and OCR2A when MGM2:0 = 7 (See Table 18-4 on page 154). The actual OC2x value will only be visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is generated by clearing (or setting) the OC2x Register at the compare match between OCR2x and TCNT2 when the counter increments, and setting (or clearing) the OC2x Register at compare match between OCR2x and TCNT2 when the counter decrements. The PWM frequency for the output when using phase correct PWM can be calculated by the following equation: The N variable represents the prescale factor (1, 8, 32, 64, 128, 256, or 1024). The extreme values for the OCR2A Register represent special cases when generating a PWM waveform output in the phase correct PWM mode. If the OCR2A is set equal to BOTTOM, the output will be continuously low and if set equal to MAX the output will be continuously high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. At the very start of period 2 in Figure 18-7 on page 148 OCnx has a transition from high to low even though there is no Compare Match. The point of this transition is to guarantee symmetry around BOTTOM. There are two cases that give a transition without Compare Match. • OCR2A changes its value from MAX, like in Figure 18-7 on page 148. When the OCR2A value is MAX the OCn pin value is the same as the result of a down-counting compare match. To ensure symmetry around BOTTOM the OCn value at MAX must correspond to the result of an up-counting Compare Match • The timer starts counting from a value higher than the one in OCR2A, and for that reason misses the Compare Match and hence the OCn change that would have happened on the way up 18.8 Timer/counter timing diagrams The following figures show the Timer/Counter in synchronous mode, and the timer clock (clkT2) is therefore shown as a clock enable signal. In asynchronous mode, clkI/O should be replaced by the Timer/Counter Oscillator clock. The figures include information on when Interrupt Flags are set. Figure 18-8 contains timing data for basic Timer/Counter operation. The figure shows the count sequence close to the MAX value in all modes other than phase correct PWM mode. Figure 18-8. Timer/counter timing diagram, no prescaling. Figure 18-9 on page 150 shows the same timing data, but with the prescaler enabled. f OCnxPCPWM f clk_I/O N ⋅ 510 = ------------------ clkTn (clkI/O/1) TOVn clkI/O TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1150 2545T–AVR–05/11 ATmega48/88/168 Figure 18-9. Timer/counter timing diagram, with prescaler (fclk_I/O/8). Figure 18-10 shows the setting of OCF2A in all modes except CTC mode. Figure 18-10. Timer/counter timing diagram, setting of OCF2A, with prescaler (fclk_I/O/8). Figure 18-11 shows the setting of OCF2A and the clearing of TCNT2 in CTC mode. Figure 18-11. Timer/counter timing diagram, clear timer on compare match mode, with prescaler (fclk_I/O/8). TOVn TCNTn MAX - 1 MAX BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn OCRnx value OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2 clkI/O clkTn (clkI/O/8) OCFnx OCRnx TCNTn (CTC) TOP TOP - 1 TOP BOTTOM BOTTOM + 1 clkI/O clkTn (clkI/O/8)151 2545T–AVR–05/11 ATmega48/88/168 18.9 Asynchronous operation of Timer/Counter2 When Timer/Counter2 operates asynchronously, some considerations must be taken. • Warning: When switching between asynchronous and synchronous clocking of Timer/Counter2, the Timer Registers TCNT2, OCR2x, and TCCR2x might be corrupted. A safe procedure for switching clock source is: a. Disable the Timer/Counter2 interrupts by clearing OCIE2x and TOIE2. b. Select clock source by setting AS2 as appropriate. c. Write new values to TCNT2, OCR2x, and TCCR2x. d. To switch to asynchronous operation: Wait for TCN2xUB, OCR2xUB, and TCR2xUB. e. Clear the Timer/Counter2 Interrupt Flags. f. Enable interrupts, if needed. • The CPU main clock frequency must be more than four times the Oscillator frequency • When writing to one of the registers TCNT2, OCR2x, or TCCR2x, the value is transferred to a temporary register, and latched after two positive edges on TOSC1. The user should not write a new value before the contents of the temporary register have been transferred to its destination. Each of the five mentioned registers have their individual temporary register, which means that, for example, writing to TCNT2 does not disturb an OCR2x write in progress. To detect that a transfer to the destination register has taken place, the Asynchronous Status Register – ASSR has been implemented • When entering Power-save or ADC Noise Reduction mode after having written to TCNT2, OCR2x, or TCCR2x, the user must wait until the written register has been updated if Timer/Counter2 is used to wake up the device. Otherwise, the MCU will enter sleep mode before the changes are effective. This is particularly important if any of the Output Compare2 interrupt is used to wake up the device, since the Output Compare function is disabled during writing to OCR2x or TCNT2. If the write cycle is not finished, and the MCU enters sleep mode before the corresponding OCR2xUB bit returns to zero, the device will never receive a compare match interrupt, and the MCU will not wake up • If Timer/Counter2 is used to wake the device up from Power-save or ADC Noise Reduction mode, precautions must be taken if the user wants to re-enter one of these modes: If reentering sleep mode within the TOSC1 cycle, the interrupt will immidiately occur and the device wake up again. The result is multiple interrupts and wake-ups within one TOSC1 cycle from the first interrupt. If the user is in doubt whether the time before re-entering Power-save or ADC Noise Reduction mode is sufficient, the following algorithm can be used to ensure that one TOSC1 cycle has elapsed: a. Write a value to TCCR2x, TCNT2, or OCR2x. b. Wait until the corresponding Update Busy Flag in ASSR returns to zero. c. Enter Power-save or ADC Noise Reduction mode. • When the asynchronous operation is selected, the 32.768kHz Oscillator for Timer/Counter2 is always running, except in Power-down and Standby modes. After a Power-up Reset or wakeup from Power-down or Standby mode, the user should be aware of the fact that this Oscillator might take as long as one second to stabilize. The user is advised to wait for at least one second before using Timer/Counter2 after power-up or wake-up from Power-down or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after a wake-up from Power-down or Standby mode due to unstable clock signal upon start-up, no matter whether the Oscillator is in use or a clock signal is applied to the TOSC1 pin152 2545T–AVR–05/11 ATmega48/88/168 • Description of wake up from Power-save or ADC Noise Reduction mode when the timer is clocked asynchronously: When the interrupt condition is met, the wake up process is started on the following cycle of the timer clock, that is, the timer is always advanced by at least one before the processor can read the counter value. After wake-up, the MCU is halted for four cycles, it executes the interrupt routine, and resumes execution from the instruction following SLEEP • Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect result. Since TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be done through a register synchronized to the internal I/O clock domain. Synchronization takes place for every rising TOSC1 edge. When waking up from Power-save mode, and the I/O clock (clkI/O) again becomes active, TCNT2 will read as the previous value (before entering sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after waking up from Powersave mode is essentially unpredictable, as it depends on the wake-up time. The recommended procedure for reading TCNT2 is thus as follows: a. Write any value to either of the registers OCR2x or TCCR2x. b. Wait for the corresponding Update Busy Flag to be cleared. c. Read TCNT2. During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous timer takes 3 processor cycles plus one timer cycle. The timer is therefore advanced by at least one before the processor can read the timer value causing the setting of the Interrupt Flag. The Output Compare pin is changed on the timer clock and is not synchronized to the processor clock. 18.10 Timer/counter prescaler Figure 18-12. Prescaler for Timer/Counter2. 10-BIT T/C PRESCALER TIMER/COUNTER2 CLOCK SOURCE clkI/O clkT2S TOSC1 AS2 CS20 CS21 CS22 clkT2S/8 clkT2S/64 clkT2S/128 clkT2S/1024 clkT2S/256 clkT2S/32 PSRASY 0 Clear clkT2153 2545T–AVR–05/11 ATmega48/88/168 The clock source for Timer/Counter2 is named clkT2S. clkT2S is by default connected to the main system I/O clock clkIO. By setting the AS2 bit in ASSR, Timer/Counter2 is asynchronously clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real Time Counter (RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from Port C. A crystal can then be connected between the TOSC1 and TOSC2 pins to serve as an independent clock source for Timer/Counter2. The Oscillator is optimized for use with a 32.768kHz crystal. For Timer/Counter2, the possible prescaled selections are: clkT2S/8, clkT2S/32, clkT2S/64, clkT2S/128, clkT2S/256, and clkT2S/1024. Additionally, clkT2S as well as 0 (stop) may be selected. Setting the PSRASY bit in GTCCR resets the prescaler. This allows the user to operate with a predictable prescaler. 18.11 Register description 18.11.1 TCCR2A – Timer/counter control register A • Bits 7:6 – COM2A1:0: Compare match output A mode These bits control the Output Compare pin (OC2A) behavior. If one or both of the COM2A1:0 bits are set, the OC2A output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC2A pin must be set in order to enable the output driver. When OC2A is connected to the pin, the function of the COM2A1:0 bits depends on the WGM22:0 bit setting. Table 18-2 shows the COM2A1:0 bit functionality when the WGM22:0 bits are set to a normal or CTC mode (non-PWM). Table 18-3 on page 154 shows the COM2A1:0 bit functionality when the WGM21:0 bits are set to fast PWM mode. Bit 7 6 5 4 3 2 1 0 (0xB0) COM2A1 COM2A0 COM2B1 COM2B0 – – WGM21 WGM20 TCCR2A Read/write R/W R/W R/W R/W R R R/W R/W Initial value 0 0 0 0 0 0 0 0 Table 18-2. Compare output mode, non-PWM mode. COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected 0 1 Toggle OC2A on compare match 1 0 Clear OC2A on compare match 1 1 Set OC2A on compare match154 2545T–AVR–05/11 ATmega48/88/168 Note: 1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Fast PWM mode” on page 146 for more details. Table 18-4 shows the COM2A1:0 bit functionality when the WGM22:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 148 for more details. • Bits 5:4 – COM2B1:0: Compare match output B mode These bits control the Output Compare pin (OC2B) behavior. If one or both of the COM2B1:0 bits are set, the OC2B output overrides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to the OC2B pin must be set in order to enable the output driver. When OC2B is connected to the pin, the function of the COM2B1:0 bits depends on the WGM22:0 bit setting. Table 18-5 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to a normal or CTC mode (non-PWM). Table 18-3. Compare output mode, fast PWM mode(1). COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected 0 1 WGM22 = 0: Normal port operation, OC0A disconnected WGM22 = 1: Toggle OC2A on compare match 1 0 Clear OC2A on compare match, set OC2A at BOTTOM, (non-inverting mode) 1 1 Set OC2A on compare match, clear OC2A at BOTTOM, (inverting mode) Table 18-4. Compare output mode, phase correct PWM Mode(1). COM2A1 COM2A0 Description 0 0 Normal port operation, OC2A disconnected 0 1 WGM22 = 0: Normal port operation, OC2A disconnected WGM22 = 1: Toggle OC2A on compare match 1 0 Clear OC2A on compare match when up-counting Set OC2A on compare match when down-counting 1 1 Set OC2A on compare match when up-counting Clear OC2A on compare match when down-counting Table 18-5. Compare output mode, non-PWM mode. COM2B1 COM2B0 Description 0 0 Normal port operation, OC2B disconnected 0 1 Toggle OC2B on compare match 1 0 Clear OC2B on compare match 1 1 Set OC2B on compare match155 2545T–AVR–05/11 ATmega48/88/168 Table 18-6 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to fast PWM mode. Note: 1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 148 for more details. Table 18-7 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to phase correct PWM mode. Note: 1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Compare Match is ignored, but the set or clear is done at TOP. See “Phase correct PWM mode” on page 148 for more details. • Bits 3, 2 – Res: Reserved bits These bits are reserved bits in the Atmel ATmega48/88/168 and will always read as zero. • Bits 1:0 – WGM21:0: Waveform generation mode Combined with the WGM22 bit found in the TCCR2B Register, these bits control the counting sequence of the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used, see Table 18-8 on page 156. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes (see “Modes of operation” on page 145). Table 18-6. Compare output mode, fast PWM mode(1). COM2B1 COM2B0 Description 0 0 Normal port operation, OC2B disconnected 0 1 Reserved 1 0 Clear OC2B on compare match, set OC2B at BOTTOM, (non-inverting mode) 1 1 Set OC2B on compare match, clear OC2B at BOTTOM, (invertiing mode) Table 18-7. Compare output mode, phase correct PWM mode(1). COM2B1 COM2B0 Description 0 0 Normal port operation, OC2B disconnected 0 1 Reserved 1 0 Clear OC2B on compare match when up-counting Set OC2B on compare match when down-counting 1 1 Set OC2B on compare match when up-counting Clear OC2B on compare match when down-counting156 2545T–AVR–05/11 ATmega48/88/168 Notes: 1. MAX= 0xFF 2. BOTTOM= 0x00 18.11.2 TCCR2B – Timer/counter control register B • Bit 7 – FOC2A: Force output compare A The FOC2A bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2A bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC2A output is changed according to its COM2A1:0 bits setting. Note that the FOC2A bit is implemented as a strobe. Therefore it is the value present in the COM2A1:0 bits that determines the effect of the forced compare. A FOC2A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2A as TOP. The FOC2A bit is always read as zero. • Bit 6 – FOC2B: Force output compare B The FOC2B bit is only active when the WGM bits specify a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2B bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC2B output is changed according to its COM2B1:0 bits setting. Note that the FOC2B bit is implemented as a strobe. Therefore it is the value present in the COM2B1:0 bits that determines the effect of the forced compare. Table 18-8. Waveform generation mode bit description. Mode WGM2 WGM1 WGM0 Timer/counter mode of operation TOP Update of OCRx at TOV flag set on(1)(2) 0 0 0 0 Normal 0xFF Immediate MAX 10 0 1 PWM, phase correct 0xFF TOP BOTTOM 2 0 1 0 CTC OCRA Immediate MAX 3 0 1 1 Fast PWM 0xFF BOTTOM MAX 4 1 0 0 Reserved – – – 51 0 1 PWM, phase correct OCRA TOP BOTTOM 6 1 1 0 Reserved – – – 7 1 1 1 Fast PWM OCRA BOTTOM TOP Bit 7 6 5 4 3 2 1 0 (0xB1) FOC2A FOC2B – – WGM22 CS22 CS21 CS20 TCCR2B Read/write W W R R R R R/W R/W Initial value 0 0 0 0 0 0 0 0157 2545T–AVR–05/11 ATmega48/88/168 A FOC2B strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2B as TOP. The FOC2B bit is always read as zero. • Bits 5:4 – Res: Reserved bits These bits are reserved bits in the Atmel ATmega48/88/168 and will always read as zero. • Bit 3 – WGM22: Waveform generation mode See the description in the “TCCR2A – Timer/counter control register A” on page 153. • Bit 2:0 – CS22:0: Clock select The three Clock Select bits select the clock source to be used by the Timer/Counter, see Table 18-9. If external pin modes are used for the Timer/Counter0, transitions on the T0 pin will clock the counter even if the pin is configured as an output. This feature allows software control of the counting. 18.11.3 TCNT2 – Timer/counter register The Timer/Counter Register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the Compare Match on the following timer clock. Modifying the counter (TCNT2) while the counter is running, introduces a risk of missing a Compare Match between TCNT2 and the OCR2x Registers. 18.11.4 OCR2A – Output compare register A Table 18-9. Clock select bit description. CS22 CS21 CS20 Description 0 0 0 No clock source (timer/counter stopped) 0 0 1 clkT2S/(no prescaling) 0 1 0 clkT2S/8 (from prescaler) 0 1 1 clkT2S/32 (from prescaler) 1 0 0 clkT2S/64 (from prescaler) 1 0 1 clkT2S/128 (from prescaler) 1 1 0 clkT2S/256 (from prescaler) 1 1 1 clkT2S/1024 (from prescaler) Bit 7 6 5 4 3 2 1 0 (0xB2) TCNT2[7:0] TCNT2 Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0xB3) OCR2A[7:0] OCR2A Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0158 2545T–AVR–05/11 ATmega48/88/168 The Output Compare Register A contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2A pin. 18.11.5 OCR2B – Output compare register B The Output Compare Register B contains an 8-bit value that is continuously compared with the counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to generate a waveform output on the OC2B pin. 18.11.6 TIMSK2 – Timer/Counter2 interrupt mask register • Bit 2 – OCIE2B: Timer/Counter2 output compare match B interrupt enable When the OCIE2B bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match B interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, that is, when the OCF2B bit is set in the Timer/Counter 2 Interrupt Flag Register – TIFR2. • Bit 1 – OCIE2A: Timer/Counter2 output compare match A interrupt enable When the OCIE2A bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match A interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, that is, when the OCF2A bit is set in the Timer/Counter 2 Interrupt Flag Register – TIFR2. • Bit 0 – TOIE2: Timer/Counter2 overflow interrupt enable When the TOIE2 bit is written to one and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter2 occurs, that is, when the TOV2 bit is set in the Timer/Counter2 Interrupt Flag Register – TIFR2. 18.11.7 TIFR2 – Timer/Counter2 interrupt flag register • Bit 2 – OCF2B: Output compare flag 2 B The OCF2B bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2B – Output Compare Register2. OCF2B is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF2B is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2B (Timer/Counter2 Compare match Interrupt Enable), and OCF2B are set (one), the Timer/Counter2 Compare match Interrupt is executed. Bit 7 6 5 4 3 2 1 0 (0xB4) OCR2B[7:0] OCR2B Read/write R/W R/W R/W R/W R/W R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 (0x70) – – – – – OCIE2B OCIE2A TOIE2 TIMSK2 Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 0 0x17 (0x37) – – – – – OCF2B OCF2A TOV2 TIFR2 Read/write R R R R R R/W R/W R/W Initial value 0 0 0 0 0 0 0 0159 2545T–AVR–05/11 ATmega48/88/168 • Bit 1 – OCF2A: Output compare flag 2 A The OCF2A bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2A – Output Compare Register2. OCF2A is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF2A is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE2A (Timer/Counter2 Compare match Interrupt Enable), and OCF2A are set (one), the Timer/Counter2 Compare match Interrupt is executed. • Bit 0 – TOV2: Timer/Counter2 overflow flag The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV2 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE2A (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter2 changes counting direction at 0x00. 18.11.8 ASSR – Asynchronous status register • Bit 7 – RES: Reserved bit This bit is reserved and will always read as zero. • Bit 6 – EXCLK: Enable external clock input When EXCLK is written to one, and asynchronous clock is selected, the external clock input buffer is enabled and an external clock can be input on Timer Oscillator 1 (TOSC1) pin instead of a 32kHz crystal. Writing to EXCLK should be done before asynchronous operation is selected. Note that the crystal Oscillator will only run when this bit is zero. • Bit 5 – AS2: Asynchronous Timer/Counter2 When AS2 is written to zero, Timer/Counter2 is clocked from the I/O clock, clkI/O. When AS2 is written to one, Timer/Counter2 is clocked from a crystal Oscillator connected to the Timer Oscillator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of TCNT2, OCR2A, OCR2B, TCCR2A and TCCR2B might be corrupted. • Bit 4 – TCN2UB: Timer/Counter2 update busy When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set. When TCNT2 has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value. • Bit 3 – OCR2AUB: Output compare Register2 update busy When Timer/Counter2 operates asynchronously and OCR2A is written, this bit becomes set. When OCR2A has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2A is ready to be updated with a new value. • Bit 2 – OCR2BUB: Output compare Register2 update busy When Timer/Counter2 operates asynchronously and OCR2B is written, this bit becomes set. When OCR2B has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that OCR2B is ready to be updated with a new value. Bit 7 6 5 4 3 2 1 0 (0xB6) – EXCLK AS2 TCN2UB OCR2AUB OCR2BUB TCR2AUB TCR2BUB ASSR Read/write R R/W R/W R R R R R Initial value 0 0 0 0 0 0 0 0160 2545T–AVR–05/11 ATmega48/88/168 • Bit 1 – TCR2AUB: Timer/counter control Register2 update busy When Timer/Counter2 operates asynchronously and TCCR2A is written, this bit becomes set. When TCCR2A has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2A is ready to be updated with a new value. • Bit 0 – TCR2BUB: Timer/counter control Register2 update busy When Timer/Counter2 operates asynchronously and TCCR2B is written, this bit becomes set. When TCCR2B has been updated from the temporary storage register, this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2B is ready to be updated with a new value. If a write is performed to any of the five Timer/Counter2 Registers while its update busy flag is set, the updated value might get corrupted and cause an unintentional interrupt to occur. The mechanisms for reading TCNT2, OCR2A, OCR2B, TCCR2A and TCCR2B are different. When reading TCNT2, the actual timer value is read. When reading OCR2A, OCR2B, TCCR2A and TCCR2B the value in the temporary storage register is read. 18.11.9 GTCCR – General timer/counter control register • Bit 1 – PSRASY: Prescaler reset Timer/Counter2 When this bit is one, the Timer/Counter2 prescaler will be reset. This bit is normally cleared immediately by hardware. If the bit is written when Timer/Counter2 is operating in asynchronous mode, the bit will remain one until the prescaler has been reset. The bit will not be cleared by hardware if the TSM bit is set. Refer to the description of the “Bit 7 – TSM: Timer/counter synchronization mode” on page 139 for a description of the Timer/Counter Synchronization mode. Bit 7 6 5 4 3 2 1 0 0x23 (0x43) TSM – – – – – PSRASY PSRSYNC GTCCR Read/write R/W R R R R R R/W R/W Initial value 0 0 0 0 0 0 0 0161 2545T–AVR–05/11 ATmega48/88/168 19. SPI – Serial peripheral interface 19.1 Features • Full-duplex, three-wire synchronous data transfer • Master or slave operation • LSB first or MSB first data transfer • Seven programmable bit rates • End of transmission interrupt flag • Write collision flag protection • Wake-up from idle mode • Double speed (CK/2) master SPI mode 19.2 Overview The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the Atmel ATmega48/88/168 and peripheral devices or between several AVR devices. The USART can also be used in Master SPI mode, see “USART in SPI mode” on page 199. The PRSPI bit in “Minimizing power consumption” on page 41 must be written to zero to enable SPI module.162 2545T–AVR–05/11 ATmega48/88/168 Figure 19-1. SPI block diagram(1). Note: 1. Refer to Figure 1-1 on page 2, and Table 14-3 on page 78 for SPI pin placement. The interconnection between Master and Slave CPUs with SPI is shown in Figure 19-2 on page 163. The system consists of two shift Registers, and a Master clock generator. The SPI Master initiates the communication cycle when pulling low the Slave Select SS pin of the desired Slave. Master and Slave prepare the data to be sent in their respective shift Registers, and the Master generates the required clock pulses on the SCK line to interchange data. Data is always shifted from Master to Slave on the Master Out – Slave In, MOSI, line, and from Slave to Master on the Master In – Slave Out, MISO, line. After each data packet, the Master will synchronize the Slave by pulling high the Slave Select, SS, line. When configured as a Master, the SPI interface has no automatic control of the SS line. This must be handled by user software before communication can start. When this is done, writing a byte to the SPI Data Register starts the SPI clock generator, and the hardware shifts the eight bits into the Slave. After shifting one byte, the SPI clock generator stops, setting the end of Transmission Flag (SPIF). If the SPI Interrupt Enable bit (SPIE) in the SPCR Register is set, an interrupt is requested. The Master may continue to shift the next byte by writing it into SPDR, or signal the end of packet by pulling high the Slave Select, SS line. The last incoming byte will be kept in the Buffer Register for later use. When configured as a Slave, the SPI interface will remain sleeping with MISO tri-stated as long as the SS pin is driven high. In this state, software may update the contents of the SPI Data Register, SPDR, but the data will not be shifted out by incoming clock pulses on the SCK pin until the SS pin is driven low. As one byte has been completely shifted, the end of Transmission SPI2X SPI2X DIVIDER /2/4/8/16/32/64/128163 2545T–AVR–05/11 ATmega48/88/168 Flag, SPIF is set. If the SPI Interrupt Enable bit, SPIE, in the SPCR Register is set, an interrupt is requested. The Slave may continue to place new data to be sent into SPDR before reading the incoming data. The last incoming byte will be kept in the Buffer Register for later use. Figure 19-2. SPI master-slave interconnection. The system is single buffered in the transmit direction and double buffered in the receive direction. This means that bytes to be transmitted cannot be written to the SPI Data Register before the entire shift cycle is completed. When receiving data, however, a received character must be read from the SPI Data Register before the next character has been completely shifted in. Otherwise, the first byte is lost. In SPI Slave mode, the control logic will sample the incoming signal of the SCK pin. To ensure correct sampling of the clock signal, the minimum low and high periods should be: Low periods: Longer than 2 CPU clock cycles. High periods: Longer than 2 CPU clock cycles. When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden according to Table 19-1. For more details on automatic port overrides, refer to “Alternate port functions” on page 76. Note: See “Alternate functions of port B” on page 78 for a detailed description of how to define the direction of the user defined SPI pins. The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. For example if MOSI is placed on pin PB3, replace DD_MOSI with DDB3 and DDR_SPI with DDRB. Table 19-1. SPI pin overrides(Note:). Pin Direction, master SPI Direction, slave SPI MOSI User defined Input MISO Input User defined SCK User defined Input SS User defined Input SHIFT ENABLE164 2545T–AVR–05/11 ATmega48/88/168 Note: 1. See ”About code examples” on page 8. Assembly code example(1) SPI_MasterInit: ; Set MOSI and SCK output, all others input ldi r17,(1<>8); UBRR0L = (unsigned char)ubrr; Enable receiver and transmitter */ UCSR0B = (1<> 1) & 0x01; return ((resh << 8) | resl); }184 2545T–AVR–05/11 ATmega48/88/168 20.7.3 Receive complete flag and interrupt The USART Receiver has one flag that indicates the Receiver state. The Receive Complete (RXCn) Flag indicates if there are unread data present in the receive buffer. This flag is one when unread data exist in the receive buffer, and zero when the receive buffer is empty (that is, does not contain any unread data). If the Receiver is disabled (RXENn = 0), the receive buffer will be flushed and consequently the RXCn bit will become zero. When the Receive Complete Interrupt Enable (RXCIEn) in UCSRnB is set, the USART Receive Complete interrupt will be executed as long as the RXCn Flag is set (provided that global interrupts are enabled). When interrupt-driven data reception is used, the receive complete routine must read the received data from UDRn in order to clear the RXCn Flag, otherwise a new interrupt will occur once the interrupt routine terminates. 20.7.4 Receiver error flags The USART Receiver has three Error Flags: Frame Error (FEn), Data OverRun (DORn) and Parity Error (UPEn). All can be accessed by reading UCSRnA. Common for the Error Flags is that they are located in the receive buffer together with the frame for which they indicate the error status. Due to the buffering of the Error Flags, the UCSRnA must be read before the receive buffer (UDRn), since reading the UDRn I/O location changes the buffer read location. Another equality for the Error Flags is that they can not be altered by software doing a write to the flag location. However, all flags must be set to zero when the UCSRnA is written for upward compatibility of future USART implementations. None of the Error Flags can generate interrupts. The Frame Error (FEn) Flag indicates the state of the first stop bit of the next readable frame stored in the receive buffer. The FEn Flag is zero when the stop bit was correctly read (as one), and the FEn Flag will be one when the stop bit was incorrect (zero). This flag can be used for detecting out-of-sync conditions, detecting break conditions and protocol handling. The FEn Flag is not affected by the setting of the USBSn bit in UCSRnC since the Receiver ignores all, except for the first, stop bits. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. The Data OverRun (DORn) Flag indicates data loss due to a receiver buffer full condition. A Data OverRun occurs when the receive buffer is full (two characters), it is a new character waiting in the Receive Shift Register, and a new start bit is detected. If the DORn Flag is set there was one or more serial frame lost between the frame last read from UDRn, and the next frame read from UDRn. For compatibility with future devices, always write this bit to zero when writing to UCSRnA. The DORn Flag is cleared when the frame received was successfully moved from the Shift Register to the receive buffer. The Parity Error (UPEn) Flag indicates that the next frame in the receive buffer had a Parity Error when received. If Parity Check is not enabled the UPEn bit will always be read zero. For compatibility with future devices, always set this bit to zero when writing to UCSRnA. For more details see “Parity bit calculation” on page 176 and “Parity checker” on page 184. 20.7.5 Parity checker The Parity Checker is active when the high USART Parity mode (UPMn1) bit is set. Type of Parity Check to be performed (odd or even) is selected by the UPMn0 bit. When enabled, the Parity Checker calculates the parity of the data bits in incoming frames and compares the result with the parity bit from the serial frame. The result of the check is stored in the receive buffer together with the received data and stop bits. The Parity Error (UPEn) Flag can then be read by software to check if the frame had a Parity Error.185 2545T–AVR–05/11 ATmega48/88/168 The UPEn bit is set if the next character that can be read from the receive buffer had a Parity Error when received and the Parity Checking was enabled at that point (UPMn1 = 1). This bit is valid until the receive buffer (UDRn) is read. 20.7.6 Disabling the receiver In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing receptions will therefore be lost. When disabled (that is, the RXENn is set to zero) the Receiver will no longer override the normal function of the RxDn port pin. The Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in the buffer will be lost 20.7.7 Flushing the receive buffer The receiver buffer FIFO will be flushed when the Receiver is disabled, that is, the buffer will be emptied of its contents. Unread data will be lost. If the buffer has to be flushed during normal operation, due to for instance an error condition, read the UDRn I/O location until the RXCn Flag is cleared. The following code example shows how to flush the receive buffer. Note: 1. See ”About code examples” on page 8. 20.8 Asynchronous data reception The USART includes a clock recovery and a data recovery unit for handling asynchronous data reception. The clock recovery logic is used for synchronizing the internally generated baud rate clock to the incoming asynchronous serial frames at the RxDn pin. The data recovery logic samples and low pass filters each incoming bit, thereby improving the noise immunity of the Receiver. The asynchronous reception operational range depends on the accuracy of the internal baud rate clock, the rate of the incoming frames, and the frame size in number of bits. 20.8.1 Asynchronous clock recovery The clock recovery logic synchronizes internal clock to the incoming serial frames. Figure 20-5 on page 186 illustrates the sampling process of the start bit of an incoming frame. The sample rate is 16 times the baud rate for Normal mode, and eight times the baud rate for Double Speed mode. The horizontal arrows illustrate the synchronization variation due to the sampling process. Note the larger time variation when using the Double Speed mode (U2Xn = 1) of operation. Samples denoted zero are samples done when the RxDn line is idle (that is, no communication activity). Assembly code example(1) USART_Flush: sbis UCSRnA, RXCn ret in r16, UDRn rjmp USART_Flush C code example(1) void USART_Flush( void ) { unsigned char dummy; while ( UCSRnA & (1< 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck >= 12MHz High: > 2 CPU clock cycles for fck < 12MHz, 3 CPU clock cycles for fck >= 12MHz VCC GND XTAL1 SCK MISO MOSI RESET +1.8V - 5.5V AVCC +1.8V - 5.5V(2)299 2545T–AVR–05/11 ATmega48/88/168 28.8.1 Serial programming pin mapping 28.8.2 Serial programming algorithm When writing serial data to the Atmel ATmega48/88/168, data is clocked on the rising edge of SCK. When reading data from the ATmega48/88/168, data is clocked on the falling edge of SCK. See Figure 28-9 on page 302 for timing details. To program and verify the ATmega48/88/168 in the serial programming mode, the following sequence is recommended (See Serial Programming Instruction set in Table 28-17 on page 300): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to “0”. In some systems, the programmer can not guarantee that SCK is held low during power-up. In this case, RESET must be given a positive pulse of at least two CPU clock cycles duration after SCK has been set to “0”. 2. Wait for at least 20ms and enable serial programming by sending the Programming Enable serial instruction to pin MOSI. 3. The serial programming instructions will not work if the communication is out of synchronization. When in sync. the second byte (0x53), will echo back when issuing the third byte of the Programming Enable instruction. Whether the echo is correct or not, all four bytes of the instruction must be transmitted. If the 0x53 did not echo back, give RESET a positive pulse and issue a new Programming Enable command. 4. The Flash is programmed one page at a time. The memory page is loaded one byte at a time by supplying the 6 LSB of the address and data together with the Load Program Memory Page instruction. To ensure correct loading of the page, the data low byte must be loaded before data high byte is applied for a given address. The Program Memory Page is stored by loading the Write Program Memory Page instruction with the 7 MSB of the address. If polling (RDY/BSY) is not used, the user must wait at least tWD_FLASH before issuing the next page (see Table 28-16 on page 300). Accessing the serial programming interface before the Flash write operation completes can result in incorrect programming. 5. A: The EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. If polling (RDY/BSY) is not used, the user must wait at least tWD_EEPROM before issuing the next byte (see Table 28-16 on page 300). In a chip erased device, no 0xFFs in the data file(s) need to be programmed. B: The EEPROM array is programmed one page at a time. The Memory page is loaded one byte at a time by supplying the 6 LSB of the address and data together with the Load EEPROM Memory Page instruction. The EEPROM Memory Page is stored by loading the Write EEPROM Memory Page Instruction with the 7 MSB of the address. When using EEPROM page access only byte locations loaded with the Load EEPROM Memory Page instruction is altered. The remaining locations remain unchanged. If polling (RDY/BSY) is not used, the used must wait at least tWD_EEPROM before issuing the next byte (See Table Table 28-15. Pin mapping serial programming. Symbol Pins I/O Description MOSI PB3 I Serial Data in MISO PB4 O Serial Data out SCK PB5 I Serial Clock300 2545T–AVR–05/11 ATmega48/88/168 28-16 on page 300). In a chip erased device, no 0xFF in the data file(s) need to be programmed. 6. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO. 7. At the end of the programming session, RESET can be set high to commence normal operation. 8. Power-off sequence (if needed): Set RESET to “1”. Turn VCC power off. 28.8.3 Serial programming instruction set Table 28-17 and Figure 28-8 on page 302 describes the instruction set. Table 28-16. Typical wait delay before writing the next flash or EEPROM location. Symbol Minimum wait delay tWD_FLASH 4.5ms tWD_EEPROM 3.6ms tWD_ERASE 9.0ms Table 28-17. Serial programming instruction set (hexadecimal values). Instruction/operation Instruction format Byte 1 Byte 2 Byte 3 Byte 4 Programming enable $AC $53 $00 $00 Chip erase (program memory/EEPROM) $AC $80 $00 $00 Poll RDY/BSY $F0 $00 $00 data byte out Load instructions Load extended address byte(1) $4D $00 Extended adr $00 Load program memory page, high byte $48 $00 adr LSB high data byte in Load program memory page, low byte $40 $00 adr LSB low data byte in Load EEPROM memory page (page access) $C1 $00 0000 000aa data byte in Read instructions Read program memory, high byte $28 adr MSB adr LSB high data byte out Read program memory, low byte $20 adr MSB adr LSB low data byte out Read EEPROM memory $A0 0000 00aa aaaa aaaa data byte out Read lock bits $58 $00 $00 data byte out Read signature byte $30 $00 0000 000aa data byte out Read fuse bits $50 $00 $00 data byte out Read fuse high bits $58 $08 $00 data byte out Read extended fuse bits $50 $08 $00 data byte out Read calibration byte $38 $00 $00 data byte out301 2545T–AVR–05/11 ATmega48/88/168 Notes: 1. Not all instructions are applicable for all parts. 2. a = address. 3. Bits are programmed ‘0’, unprogrammed ‘1’. 4. To ensure future compatibility, unused fuses and lock bits should be unprogrammed (‘1’). 5. Refer to the correspondig section for fuse and lock bits, calibration and signature bytes and page size. 6. Instructions accessing program memory use a word address. This word may be random within the page range. 7. See htt://www.atmel.com/avr for application notes regarding programming and programmers. If the LSB in RDY/BSY data byte out is ‘1’, a programming operation is still pending. Wait until this bit returns ‘0’ before the next instruction is carried out. Within the same page, the low data byte must be loaded prior to the high data byte. After data is loaded to the page buffer, program the EEPROM page, see Figure 28-8. Write instructions(6) Write program memory page $4C adr MSB adr LSB $00 Write EEPROM memory $C0 0000 00aa aaaa aaaa data byte in Write EEPROM memory page (page access) $C2 0000 00aa aaaa aa00 $00 Write lock bits $AC $E0 $00 data byte in Write fuse bits $AC $A0 $00 data byte in Write fuse high bits $AC $A8 $00 data byte in Write extended fuse bits $AC $A4 $00 data byte in Table 28-17. Serial programming instruction set (hexadecimal values). (Continued) Instruction/operation Instruction format Byte 1 Byte 2 Byte 3 Byte 4302 2545T–AVR–05/11 ATmega48/88/168 Figure 28-8. Serial programming instruction example. 28.8.4 SPI serial programming characteristics Figure 28-9. Serial programming waveforms. For characteristics of the SPI module see “SPI timing characteristics” on page 309. Byte 1 Byte 2 Byte 3 Byte 4 Adr MSB Adr LSB Bit 15 B 0 Serial programming instruction Program memory/ EEPROM memory Page 0 Page 1 Page 2 Page N-1 Page buffer Write program memory page/ Write EEPROM memory page Load program memory page (high/low byte)/ Load EEPROM memory page (page access) Byte 1 Byte 2 Byte 3 Byte 4 Bit 15 B 0 Adr MSB Adr LSB Page offset Page number Adr MSB Adr LSB MSB MSB LSB LSB SERIAL CLOCK INPUT (SCK) SERIAL DATA INPUT (MOSI) (MISO) SAMPLE SERIAL DATA OUTPUT303 2545T–AVR–05/11 ATmega48/88/168 29. Electrical characteristics 29.1 Absolute maximum ratings* 29.2 DC characteristics Operating temperature................................... -55°C to +125°C *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Storage temperature...................................... -65°C to +150°C Voltage on any pin except RESET with respect to ground .................................-0.5V to VCC+0.5V Voltage on RESET with respect to ground ......-0.5V to +13.0V Maximum operating voltage.............................................. 6.0V DC current per I/O pin.................................................. 40.0mA DC current VCC and GND pins .................................. 200.0mA TA = -40°C to 85°C, VCC = 1.8V to 5.5V (unless otherwise noted). Symbol Parameter Condition Minimum Typical Maximum Units VIL Input low voltage, except XTAL1 and RESET pin VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V -0.5 -0.5 0.2VCC(1) 0.3VCC(1) V VIH Input high voltage, except XTAL1 and RESET pins VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.7VCC(2) 0.6VCC(2) VCC + 0.5 VCC + 0.5 VIL1 Input low voltage, XTAL1 pin VCC = 1.8V - 5.5V -0.5 0.1VCC(1) VIH1 Input high voltage, XTAL1 pin VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.8VCC(2) 0.7VCC(2) VCC + 0.5 VCC + 0.5 VIL2 Input low voltage, RESET pin VCC = 1.8V - 5.5V -0.5 0.2VCC(1) VIH2 Input high voltage, RESET pin VCC = 1.8V - 5.5V 0.9VCC(2) VCC + 0.5 VIL3 Input low voltage, RESET pin as I/O VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V -0.5 -0.5 0.2VCC(1) 0.3VCC(1) VIH3 Input high voltage, RESET pin as I/O VCC = 1.8V - 2.4V VCC = 2.4V - 5.5V 0.7VCC(2) 0.6VCC(2) VCC + 0.5 VCC + 0.5 VOL Output low voltage(3), RESET pin as I/O I OL = 20mA, VCC = 5V IOL = 6mA, VCC = 3V 0.7 0.5 VOH Output high voltage(4), RESET pin as I/O I OH = -20mA, VCC = 5V I OH = -10mA, VCC = 3V 4.2 2.3 IIL Input leakage current I/O pin VCC = 5.5V, pin low (absolute value) 1 µA I IH Input leakage current I/O pin VCC = 5.5V, pin high (absolute value) 1 RRST Reset pull-up resistor 30 60 kΩ RPU I/O pin pull-up resistor 20 50304 2545T–AVR–05/11 ATmega48/88/168 Notes: 1. “Max” means the highest value where the pin is guaranteed to be read as low 2. “Min” means the lowest value where the pin is guaranteed to be read as high 3. Although each I/O port can sink more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed: ATmega48/88/168: 1] The sum of all IOL, for ports C0 - C5, ADC7, ADC6 should not exceed 100mA. 2] The sum of all IOL, for ports B0 - B5, D5 - D7, XTAL1, XTAL2 should not exceed 100mA. 3] The sum of all IOL, for ports D0 - D4, RESET should not exceed 100mA. If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition. 4. Although each I/O port can source more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed: ATmega48/88/168: 1] The sum of all IOH, for ports C0 - C5, D0- D4, ADC7, RESET should not exceed 150mA. 2] The sum of all IOH, for ports B0 - B5, D5 - D7, ADC6, XTAL1, XTAL2 should not exceed 150mA. If IIOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition. 5. Values with “Minimizing power consumption” on page 41 enabled (0xFF). ICC Power supply current(5) Active 1MHz, VCC = 2V (Atmel ATmega48/88/168V) 0.55 mA Active 4MHz, VCC = 3V (Atmel ATmega48/88/168L) 3.5 Active 8MHz, VCC = 5V (Atmel ATmega48/88/168) 12 Idle 1MHz, VCC = 2V (ATmega48/88/168V) 0.25 0.5 Idle 4MHz, VCC = 3V (ATmega48/88/168L) 1.5 Idle 8MHz, VCC = 5V (ATmega48/88/168) 5.5 Power-down mode WDT enabled, VCC = 3V 8 15 µA WDT disabled, VCC = 3V 1 2 VACIO Analog comparator input offset voltage VCC = 5V Vin = VCC/2 10 40 mV IACLK Analog comparator input leakage current VCC = 5V Vin = VCC/2 -50 50 nA t ACID Analog comparator propagation delay VCC = 2.7V VCC = 4.0V 750 500 ns TA = -40°C to 85°C, VCC = 1.8V to 5.5V (unless otherwise noted). (Continued) Symbol Parameter Condition Minimum Typical Maximum Units305 2545T–AVR–05/11 ATmega48/88/168 29.3 Speed grades Maximum frequency is dependent on VCC. As shown in Figure 29-1 and Figure 29-2, the Maximum Frequency vs. VCC curve is linear between 1.8V < VCC < 2.7V and between 2.7V < VCC < 4.5V. Figure 29-1. Maximum frequency vs. VCC, Atmel ATmega48V/88V/168V. Figure 29-2. Maximum frequency vs. VCC, ATmega48/88/168. 10MHz 4MHz 1.8V 2.7V 5.5V Safe operating area 20MHz 10MHz 2.7V 4.5V 5.5V Safe operating area306 2545T–AVR–05/11 ATmega48/88/168 29.4 Clock characteristics 29.4.1 Calibrated internal RC oscillator accuracy Notes: 1. Voltage range for Atmel ATmega48V/88V/168V. 2. Voltage range for Atmel ATmega48/88/168. 29.4.2 External clock drive waveforms Figure 29-3. External clock drive waveforms. 29.4.3 External clock drive Table 29-1. Calibration accuracy of internal RC oscillator. Frequency VCC Temperature Calibration accuracy Factory calibration 8.0MHz 3V 25°C ±10% User calibration 7.3MHz - 8.1MHz 1.8V - 5.5V(1) 2.7V - 5.5V(2) -40°C - 85°C ±1% VIL1 VIH1 Table 29-2. External clock drive. Symbol Parameter VCC = 1.8V - 5.5V VCC = 2.7V - 5.5V VCC = 4.5V - 5.5V Min. Max. Min. Max. Min. Max. Units 1/tCLCL Oscillator frequency 0 4 0 10 0 20 MHz tCLCL Clock period 250 100 50 tCHCX High time 100 40 20 ns tCLCX Low time 100 40 20 tCLCH Rise time 2.0 1.6 0.5 μs tCHCL Fall time 2.0 1.6 0.5 ΔtCLCL Change in period from one clock cycle to the next 2 2 2%307 2545T–AVR–05/11 ATmega48/88/168 29.5 System and reset characteristics Note: 1. The power-on reset will not work unless the supply voltage has been below VPOT (falling). Notes: 1. VBOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is tested down to VCC = VBOT during the production test. This guarantees that a brown-out reset will occur before VCC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. The test is performed using BODLEVEL = 110 and BODLEVEL = 101 for Atmel ATmega48V/88V/168V, and BODLEVEL = 101 and BODLEVEL = 100 for Atmel ATmega48/88/168. Table 29-3. Reset, brown-out and internal voltage characteristics. Symbol Parameter Condition Min. Typ. Max. Units VPOT Power-on reset threshold voltage (rising) 0.7 1.0 1.4 V Power-on reset threshold voltage (falling)(1) 0.05 0.9 1.3 VPONSR Power-on slope rate 0.01 4.5 V/ms VRST RESET pin threshold voltage 0.2VCC 0.9VCC V tRST Minimum pulse width on RESET pin 2.5 µs VHYST Brown-out detector hysteresis 50 mV tBOD Min pulse width on brown-out reset 2 µs VBG Bandgap reference voltage VCC = 2.7 TA = 25°C 1.0 1.1 1.2 V t BG Bandgap reference start-up time VCC = 2.7 TA = 25°C 40 70 µs I BG Bandgap reference current consumption VCC = 2.7 TA = 25°C 10 µA Table 29-4. BODLEVEL fuse coding(1). BODLEVEL 2:0 Fuses Min. VBOT Typ. VBOT Max. VBOT Units 111 BOD disabled 110 1.7 1.8 2.0 101 2.5 2.7 2.9 V 100 4.1 4.3 4.5 011 Reserved 010 001 000308 2545T–AVR–05/11 ATmega48/88/168 29.6 2-wire serial interface characteristics Table 29-5 describes the requirements for devices connected to the 2-wire Serial Bus. The Atmel ATmega48/88/168 2-wire Serial Interface meets or exceeds these requirements under the noted conditions. Timing symbols refer to Figure 29-4 on page 309. Notes: 1. In ATmega48/88/168, this parameter is characterized and not 100% tested. 2. Required only for fSCL > 100kHz. Table 29-5. 2-wire serial bus requirements. Symbol Parameter Condition Min. Max. Units VIL Input low-voltage -0.5 0.3VCC V VIH Input high-voltage 0.7VCC VCC + 0.5 Vhys(1) Hysteresis of schmitt trigger inputs 0.05VCC(2) – VOL(1) Output low-voltage 3mA sink current 0 0.4 tr (1) Rise time for both SDA and SCL 20 + 0.1Cb (3)(2) 300 tof ns (1) Output fall time from VIHmin to VILmax 10pF < Cb < 400pF(3) 20 + 0.1Cb (3)(2) 250 tSP(1) Spikes suppressed by input filter 0 50(2) Ii Input current each I/O pin 0.1VCC < Vi < 0.9VCC -10 10 µA Ci (1) Capacitance for each I/O pin – 10 pF fSCL SCL clock frequency fCK(4) > max(16fSCL, 250kHz)(5) 0 400 kHz Rp Value of pull-up resistor fSCL ≤ 100kHz fSCL > 100kHz tHD;STA Hold time (repeated) START condition fSCL ≤ 100kHz 4.0 – µs fSCL > 100kHz 0.6 – tLOW Low period of the SCL clock fSCL ≤ 100kHz 4.7 – fSCL > 100kHz 1.3 – tHIGH High period of the SCL clock fSCL ≤ 100kHz 4.0 – fSCL > 100kHz 0.6 – tSU;STA Setup time for a repeated START condition fSCL ≤ 100kHz 4.7 – fSCL > 100kHz 0.6 – tHD;DAT Data hold time fSCL ≤ 100kHz 0 3.45 fSCL > 100kHz 0 0.9 tSU;DAT Data setup time fSCL ≤ 100kHz 250 – ns fSCL > 100kHz 100 – tSU;STO Setup time for STOP condition fSCL ≤ 100kHz 4.0 – µs fSCL > 100kHz 0.6 – tBUF Bus free time between a STOP and START condition fSCL ≤ 100kHz 4.7 – fSCL > 100kHz 1.3 – VCC – 0.4V 3mA ---------------------------- 1000ns Cb ----------------- Ω VCC – 0.4V 3mA ---------------------------- 300ns Cb --------------309 2545T–AVR–05/11 ATmega48/88/168 3. Cb = capacitance of one bus line in pF. 4. fCK = CPU clock frequency. 5. This requirement applies to all Atmel ATmega48/88/168 2-wire Serial Interface operation. Other devices connected to the 2- wire Serial Bus need only obey the general fSCL requirement. Figure 29-4. 2-wire serial bus timing. 29.7 SPI timing characteristics See Figure 29-5 on page 310 and Figure 29-6 on page 310 for details. Note: 1. In SPI programming mode the minimum SCK high/low period is: - 2 tCLCL for fCK < 12MHz - 3 tCLCL for fCK > 12MHz t SU;STA t LOW t HIGH t LOW t of t HD;STA t HD;DAT t SU;DAT t SU;STO t BUF SCL SDA t r Table 29-6. SPI timing parameters. Description Mode Minimum Typical Maximum 1 SCK period Master See Table 19-5 on page 169 ns 2 SCK high/low Master 50% duty cycle 3 Rise/fall time Master 3.6 4 Setup Master 10 5 Hold Master 10 6 Out to SCK Master 0.5 • tsck 7 SCK to out Master 10 8 SCK to out high Master 10 9 SS low to out Slave 15 10 SCK period Slave 4 • tck 11 SCK high/low(1) Slave 2 • tck 12 Rise/fall time Slave 1600 13 Setup Slave 10 14 Hold Slave tck 15 SCK to out Slave 15 16 SCK to SS high Slave 20 17 SS high to tri-state Slave 10 18 SS low to SCK Slave 20310 2545T–AVR–05/11 ATmega48/88/168 Figure 29-5. SPI interface timing requirements (master mode). Figure 29-6. SPI interface timing requirements (slave mode). MOSI (Data output) SCK (CPOL = 1) MISO (Data input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 6 1 2 2 4 5 3 7 8 MISO (Data output) SCK (CPOL = 1) MOSI (Data input) SCK (CPOL = 0) SS MSB LSB MSB LSB ... ... 10 11 11 13 14 12 15 17 9 X 16311 2545T–AVR–05/11 ATmega48/88/168 29.8 ADC characteristics Note: 1. AVCC absolute min./max.: 1.8V/5.5V Table 29-7. ADC characteristics. Symbol Parameter Condition Minimum Typical Maximum Units Resolution 10 Bits Absolute accuracy (Including INL, DNL, quantization error, gain and offset error) VREF = 4V, VCC = 4V, ADC clock = 200kHz 2 LSB VREF = 4V, VCC = 4V, ADC clock = 1MHz 4.5 VREF = 4V, VCC = 4V, ADC clock = 200kHz Noise reduction mode 2 VREF = 4V, VCC = 4V, ADC clock = 1MHz Noise reduction mode 4.5 Integral non-linearity (INL) VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.5 Differential non-linearity (DNL) VREF = 4V, VCC = 4V, ADC clock = 200kHz 0.25 Gain error VREF = 4V, VCC = 4V, ADC clock = 200kHz 2 Offset error VREF = 4V, VCC = 4V, ADC clock = 200kHz 2 Conversion time Free running conversion 13 260 µs Clock frequency 50 1000 kHz AVCC(1) Analog supply voltage VCC - 0.3 VCC + 0.3 VREF Reference voltage 1.0 AVCC V VIN Input voltage GND VREF Input bandwidth 38.5 kHz VINT Internal voltage reference 1.0 1.1 1.2 V RREF Reference input resistance 32 kΩ RAIN Analog input resistance 100 MΩ312 2545T–AVR–05/11 ATmega48/88/168 29.9 Parallel programming characteristics Figure 29-7. Parallel programming timing, including some general timing requirements. Figure 29-8. Parallel programming timing, loading sequence with timing requirements(1). Note: 1. The timing requirements shown in Figure 29-7 (that is, tDVXH, tXHXL, and tXLDX) also apply to loading operation. Data & contol (DATA, XA0/1, BS1, BS2) XTAL1 t XHXL t WLWH t DVXH t XLDX t PLWL t WLRH WR RDY/BSY PAGEL t PHPL t PLBX t BVPH t XLWL t WLBX tBVWL WLRL XTAL1 PAGEL t XLXH PLXH t t XLPH DATA ADDR0 (low byte) DATA (low byte) DATA (high byte) ADDR1 (low byte) BS1 XA0 XA1 LOAD ADDRESS (LOW BYTE) LOAD DATA (LOW BYTE) LOAD DATA (HIGH BYTE) LOAD DATA LOAD ADDRESS (LOW BYTE)313 2545T–AVR–05/11 ATmega48/88/168 Figure 29-9. Parallel programming timing, reading sequence (within the same page) with timing requirements(1). Note: 1. The timing requirements shown in Figure 29-7 on page 312 (that is, tDVXH, tXHXL, and tXLDX) also apply to reading operation. Table 29-8. Parallel programming characteristics, VCC = 5V ±10%. Symbol Parameter Min. Typ. Max. Units VPP Programming enable voltage 11.5 12.5 V IPP Programming enable current 250 µA tDVXH Data and control valid before XTAL1 high 67 ns tXLXH XTAL1 low to XTAL1 high 200 tXHXL XTAL1 pulse width high 150 tXLDX Data and control hold after XTAL1 low 67 tXLWL XTAL1 low to WR low 0 tXLPH XTAL1 low to PAGEL high 0 tPLXH PAGEL low to XTAL1 high 150 tBVPH BS1 valid before PAGEL high 67 tPHPL PAGEL pulse width high 150 tPLBX BS1 hold after PAGEL low 67 tWLBX BS2/1 hold after WR low 67 tPLWL PAGEL low to WR low 67 tBVWL BS1 valid to WR low 67 tWLWH WR pulse width low 150 tWLRL WR low to RDY/BSY low 0 1 µs tWLRH WR low to RDY/BSY high(1) 3.7 4.5 ms tWLRH_CE WR low to RDY/BSY high for chip erase(2) 7.5 9 XTAL1 OE DATA ADDR0 (low byte) DATA (low byte) DATA (high byte) ADDR1 (low byte) BS1 XA0 XA1 LOAD ADDRESS (LOW BYTE) READ DATA (LOW BYTE) READ DATA (HIGH BYTE) LOAD ADDRESS (LOW BYTE) t BVDV t OLDV t XLOL t OHDZ314 2545T–AVR–05/11 ATmega48/88/168 Notes: 1. tWLRH is valid for the write flash, write EEPROM, write fuse bits and write lock bits commands. 2. tWLRH_CE is valid for the chip erase command. t XLOL XTAL1 low to OE low 0 ns t BVDV BS1 valid to DATA valid 0 250 tOLDV OE low to DATA valid 250 t OHDZ OE high to DATA tri-stated 250 Table 29-8. Parallel programming characteristics, VCC = 5V ±10%. (Continued) Symbol Parameter Min. Typ. Max. Units315 2545T–AVR–05/11 ATmega48/88/168 30. Typical characteristics The following charts show typical behavior. These figures are not tested during manufacturing. All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups enabled. A square wave generator with rail-to-rail output is used as clock source. All Active- and Idle current consumption measurements are done with all bits in the PRR register set and thus, the corresponding I/O modules are turned off. Also the Analog Comparator is disabled during these measurements. Table 30-1 on page 321 and Table 30-2 on page 321 show the additional current consumption compared to ICC Active and ICC Idle for every I/O module controlled by the Power Reduction Register. See “Power reduction register” on page 41 for details. The power consumption in Power-down mode is independent of clock selection. The current consumption is a function of several factors such as: operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The current drawn from capacitive loaded pins may be estimated (for one pin) as CL*VCC*f where CL = load capacitance, VCC = operating voltage and f = average switching frequency of I/O pin. The parts are characterized at frequencies higher than test limits. Parts are not guaranteed to function properly at frequencies higher than the ordering code indicates. The difference between current consumption in Power-down mode with Watchdog Timer enabled and Power-down mode with Watchdog Timer disabled represents the differential current drawn by the Watchdog Timer. 30.1 Active supply current Figure 30-1. Active supply current vs. frequency (0.1MHz - 1.0MHz). 5.5V 5.0V 4.5V 4.0V 3.3V 2.7V 1.8V 0 0.2 0.4 0.6 0.8 1 1.2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)316 2545T–AVR–05/11 ATmega48/88/168 Figure 30-2. Active supply current vs. frequency (1MHz - 24MHz). Figure 30-3. Active supply current vs. VCC (internal RC oscillator, 128kHz). 0 2 4 6 8 10 12 14 16 18 0 4 8 12 16 20 24 Frequency (MHz) ICC (mA) 2.7V 1.8V 3.3V 4.0V 4.5V 5.0V 5.5V , 85°C 25°C -40°C 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)317 2545T–AVR–05/11 ATmega48/88/168 Figure 30-4. Active supply current vs. VCC (internal RC oscillator, 1MHz). Figure 30-5. Active supply current vs. VCC (internal RC oscillator, 8MHz). , 85°C 25°C -40°C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) , 85°C 25°C -40°C 0 1 2 3 4 5 6 7 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)318 2545T–AVR–05/11 ATmega48/88/168 Figure 30-6. Active supply current vs. VCC (32kHz external oscillator). 30.2 Idle supply current Figure 30-7. Idle supply current vs. frequency (0.1MHz - 1.0MHz). 25°C 0 10 20 30 40 50 60 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 5.5V 5.0V 4.5V 4.0V 3.3V 2.7V 1.8V 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA)319 2545T–AVR–05/11 ATmega48/88/168 Figure 30-8. Idle supply current vs. frequency (1MHz - 24MHz). Figure 30-9. Idle supply current vs. VCC (internal RC oscillator, 128kHz). 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 4 8 12 16 20 24 Frequency (MHz) ICC (mA) 2.7V 1.8V 3.3V 4.0V 4.5V 5.0V 5.5V 85°C 25°C -40°C 0 0.005 0.01 0.015 0.02 0.025 0.03 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)320 2545T–AVR–05/11 ATmega48/88/168 Figure 30-10. Idle supply current vs. VCC (internal RC oscillator, 1MHz). Figure 30-11. Idle supply current vs. VCC (internal RC oscillator, 8MHz). , 85°C 25°C -40°C 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) , 85°C 25°C -40°C 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)321 2545T–AVR–05/11 ATmega48/88/168 Figure 30-12. Idle supply current vs. VCC (32kHz external oscillator). 30.3 Supply current of I/O modules The tables and formulas below can be used to calculate the additional current consumption for the different I/O modules in Active and Idle mode. The enabling or disabling of the I/O modules are controlled by the Power Reduction Register. See “Power reduction register” on page 41 for details. 25°C 0 5 10 15 20 25 30 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) Table 30-1. Additional current consumption for the different I/O modules (absolute values). PRR bit Typical numbers VCC = 2V, F = 1MHz VCC = 3V, F = 4MHz VCC = 5V, F = 8MHz PRUSART0 8.0µA 51µA 220µA PRTWI 12µA 75µA 315µA PRTIM2 11µA 72µA 300µA PRTIM1 5.0µA 32µA 130µA PRTIM0 4.0µA 24µA 100µA PRSPI 15µA 95µA 400µA PRADC 12µA 75µA 315µA Table 30-2. Additional current consumption (percentage) in active and idle mode. PRR bit Additional current consumption compared to active with external clock (see Figure 30-1 on page 315 and Figure 30-2 on page 316) Additional current consumption compared to Idle with external clock (see Figure 30-7 on page 318 and Figure 30-8 on page 319) PRUSART0 3.3% 18% PRTWI 4.8% 26% PRTIM2 4.7% 25%322 2545T–AVR–05/11 ATmega48/88/168 It is possible to calculate the typical current consumption based on the numbers from Table 30-2 on page 321 for other VCC and frequency settings than listed in Table 30-1 on page 321. 30.3.0.1 Example 1 Calculate the expected current consumption in idle mode with USART0, TIMER1, and TWI enabled at VCC = 3.0V and F = 1MHz. From Table 30-2 on page 321, third column, we see that we need to add 18% for the USART0, 26% for the TWI, and 11% for the TIMER1 module. Reading from Figure 30-7 on page 318, we find that the idle current consumption is ~0.075mA at VCC = 3.0V and F = 1MHz. The total current consumption in idle mode with USART0, TIMER1, and TWI enabled, gives: 30.3.0.2 Example 2 Same conditions as in example 1, but in active mode instead. From Table 30-2 on page 321, second column we see that we need to add 3.3% for the USART0, 4.8% for the TWI, and 2.0% for the TIMER1 module. Reading from Figure 30-1 on page 315, we find that the active current consumption is ~0.42mA at VCC = 3.0V and F = 1MHz. The total current consumption in idle mode with USART0, TIMER1, and TWI enabled, gives: 30.3.0.3 Example 3 All I/O modules should be enabled. Calculate the expected current consumption in active mode at VCC = 3.6V and F = 10MHz. We find the active current consumption without the I/O modules to be ~ 4.0mA (from Figure 30-2 on page 316). Then, by using the numbers from Table 30-2 on page 321 - second column, we find the total current consumption: PRTIM1 2.0% 11% PRTIM0 1.6% 8.5% PRSPI 6.1% 33% PRADC 4.9% 26% Table 30-2. Additional current consumption (percentage) in active and idle mode. (Continued) PRR bit Additional current consumption compared to active with external clock (see Figure 30-1 on page 315 and Figure 30-2 on page 316) Additional current consumption compared to Idle with external clock (see Figure 30-7 on page 318 and Figure 30-8 on page 319) ICCtotal ≈ ≈ 0.075mA • ( ) 1 0.18 0.26 0.11 +++ 0.116mA ICCtotal ≈ ≈ 0.42mA • ( ) 1 0.033 0.048 0.02 +++ 0.46mA ICCtotal ≈ ≈ 4.0mA • ( ) 1 0.033 0.048 0.047 0.02 0.016 0.061 0.049 + + + ++ + + 5.1mA323 2545T–AVR–05/11 ATmega48/88/168 30.4 Power-down supply current Figure 30-13. Power-down supply current vs. VCC (watchdog timer disabled). Figure 30-14. Power-down supply current vs. VCC (watchdog timer enabled). 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C 0 2 4 6 8 10 12 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)324 2545T–AVR–05/11 ATmega48/88/168 30.5 Power-save supply current Figure 30-15. Power-save supply current vs. VCC (watchdog timer disabled). 30.6 Standby supply current Figure 30-16. Standby supply current vs. VCC (low power crystal oscillator). 25°C 0 2 4 6 8 10 12 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 6MHz Xtal 6MHz Res. 4MHz Xtal 4MHz Res. 455kHz Res. 32kHz Xtal 2MHz Xtal 2MHz Res. 1MHz Res. 0 20 40 60 80 100 120 140 160 180 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)325 2545T–AVR–05/11 ATmega48/88/168 Figure 30-17. Standby supply current vs. VCC (full swing crystal oscillator). 30.7 Pin pull-up Figure 30-18. I/O pin pull-up resistor current vs. input voltage (VCC = 5V). 6MHz Xtal (ckopt) 4MHz Xtal (ckopt) 2MHz Xtal (ckopt) 16MHz Xtal 12MHz Xtal 0 50 100 150 200 250 300 350 400 450 500 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C 0 20 40 60 80 100 120 140 160 0123456 VOP (V) IOP (µA)326 2545T–AVR–05/11 ATmega48/88/168 Figure 30-19. I/O pin pull-up resistor current vs. input voltage (VCC = 2.7V). Figure 30-20. Reset pull-up resistor current vs. reset pin voltage (VCC = 5V). 85°C 25°C -40°C 0 10 20 30 40 50 60 70 80 90 0 0.5 1 1.5 2 2.5 3 VOP (V) IOP (µA) 0 20 40 60 80 100 120 0123456 VRESET (V) IRESET (µA) -40°C 25°C 85°C327 2545T–AVR–05/11 ATmega48/88/168 Figure 30-21. Reset pull-up resistor current vs. reset pin voltage (VCC = 2.7V). 30.8 Pin driver strength Figure 30-22. I/O pin source current vs. output voltage (VCC = 5V). -40°C 0 10 20 30 40 50 60 70 0 0.5 1 1.5 2 2.5 3 VRESET (V) IRESET (µA) 25°C 85°C 85°C 25°C -40°C 0 10 20 30 40 50 60 70 80 90 0123456 VOH (V) IOH (mA)328 2545T–AVR–05/11 ATmega48/88/168 Figure 30-23. I/O pin source current vs. output voltage (VCC = 2.7V). Figure 30-24. I/O pin source current vs. output voltage (VCC = 1.8V). 85°C 25°C -40°C 0 5 10 15 20 25 30 35 0 0.5 1 1.5 2 2.5 3 VOH (V) IOH (mA) 85°C 25°C -40°C 0 1 2 3 4 5 6 7 8 9 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOH (V) IOH (mA)329 2545T–AVR–05/11 ATmega48/88/168 Figure 30-25. I/O pin sink current vs. output voltage (VCC = 5V). Figure 30-26. I/O pin sink current vs. output voltage (VCC = 2.7V). 85°C 25°C 0 10 20 30 40 50 60 70 80 0 0.5 1 1.5 2 2.5 VOL (V) IOL (mA) 85°C 25°C -40°C 0 5 10 15 20 25 30 35 40 0 0.5 1 1.5 2 2.5 VOL (V) IOL (mA)330 2545T–AVR–05/11 ATmega48/88/168 Figure 30-27. I/O pin sink current vs. output voltage (VCC = 1.8V). 30.9 Pin thresholds and hysteresis Figure 30-28. I/O pin input threshold voltage vs. VCC (VIH, I/O pin read as '1'). 85°C 25°C -40°C 0 2 4 6 8 10 12 14 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VOL (V) IOL (mA) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V)331 2545T–AVR–05/11 ATmega48/88/168 Figure 30-29. I/O pin input threshold voltage vs. VCC (VIL, I/O pin read as '0'). Figure 30-30. I/O pin input hystreresis vs. Vcc. 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.1 0.2 0.3 0.4 0.5 0.6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input hysteresis (V)332 2545T–AVR–05/11 ATmega48/88/168 Figure 30-31. Reset input threshold voltage vs. VCC (VIH, reset pin read as '1'). Figure 30-32. Reset input threshold voltage vs. VCC (VIL, reset pin read as '0'). 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V) 85°C 25°C -40°C 0 0.5 1 1.5 2 2.5 3 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Threshold (V)333 2545T–AVR–05/11 ATmega48/88/168 Figure 30-33. Reset input pin hysteresis vs. VCC. 30.10 BOD thresholds and analog comparator offset Figure 30-34. BOD thresholds vs. temperature (BODLEVEL is 4.3V). VIL 0 100 200 300 400 500 600 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Input hysteresis (mV) 4.2 4.25 4.3 4.35 4.4 4.45 4.5 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) Threshold (V) Rising Vcc Falling Vcc334 2545T–AVR–05/11 ATmega48/88/168 Figure 30-35. BOD thresholds vs. temperature (BODLEVEL is 2.7V). Figure 30-36. BOD thresholds vs. temperature (BODLEVEL is 1.8V). 2.6 2.65 2.7 2.75 2.8 2.85 2.9 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) Threshold (V) Rising Vcc Falling Vcc 1.76 1.78 1.8 1.82 1.84 1.86 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) Threshold (V) Rising Vcc Falling Vcc335 2545T–AVR–05/11 ATmega48/88/168 Figure 30-37. Bandgap voltage vs. VCC. Figure 30-38. Analog comparator offset voltage vs. common mode voltage (VCC = 5V). -40°C 85°C 1.08 1.085 1.09 1.095 1.1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 VCC (V) Bandgap voltage (V) -40°C 85°C 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Common Mode Voltage (V) Analog comparator offset voltage (V)336 2545T–AVR–05/11 ATmega48/88/168 Figure 30-39. Analog comparator offset voltage vs. common mode voltage (VCC = 2.7V). 30.11 Internal oscillator speed Figure 30-40. Watchdog oscillator frequency vs. VCC. -40°C 85°C 0 0.5 1 1.5 2 2.5 3 3.5 4 0 0.5 1 1.5 2 2.5 Common Mode Voltage (V) Analog comparator offset voltage (mV) 85°C 25°C -40°C 95 100 105 110 115 120 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (kHz)337 2545T–AVR–05/11 ATmega48/88/168 Figure 30-41. Calibrated 8MHz RC oscillator frequency vs. temperature. Figure 30-42. Calibrated 8MHz RC oscillator frequency vs. VCC. 5.0V 2.7V 1.8V 7.4 7.5 7.6 7.7 7.8 7.9 8 8.1 8.2 8.3 8.4 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) FRC (MHz) 85°C 25°C -40°C 7.4 7.6 7.8 8 8.2 8.4 8.6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) FRC (MHz)338 2545T–AVR–05/11 ATmega48/88/168 Figure 30-43. Calibrated 8MHz RC oscillator frequency vs. osccal value. 30.12 Current consumption of peripheral units Figure 30-44. Brownout detector current vs. VCC. 85°C 25°C -40°C 3.5 5.5 7.5 9.5 11.5 13.5 0 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 OSCCAL VALUE FRC (MHz) 85°C 25°C -40°C 18 20 22 24 26 28 30 32 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)339 2545T–AVR–05/11 ATmega48/88/168 Figure 30-45. ADC current vs. VCC (AREF = AVCC). Figure 30-46. AREF external reference current vs. VCC. 85°C 25°C -40°C 150 200 250 300 350 400 450 500 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C 0 20 40 60 80 100 120 140 160 180 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA)340 2545T–AVR–05/11 ATmega48/88/168 Figure 30-47. Analog comparator current vs. VCC. Figure 30-48. Programming current vs. VCC. 85°C 25°C -40°C 0 20 40 60 80 100 120 140 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (µA) 85°C 25°C -40°C 0 2 4 6 8 10 12 14 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA) 85°C 25°C -40°C 0 2 4 6 8 10 12 14 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) ICC (mA)341 2545T–AVR–05/11 ATmega48/88/168 30.13 Current consumption in reset and reset pulse width Figure 30-49. Reset supply current vs. VCC (0.1MHz - 1.0MHz, excluding current through the reset pull-up). Figure 30-50. Reset supply current vs. VCC (1MHz - 24MHz, excluding current through the reset pull-up). 5.5V 5.0V 4.5V 4.0V 3.3V 2.7V 1.8V 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frequency (MHz) ICC (mA) , 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 4 8 12 16 20 24 Frequency (MHz) ICC (mA) 2.7V 1.8V 3.3V 4.0V 4.5V 5.0V 5.5V342 2545T–AVR–05/11 ATmega48/88/168 Figure 30-51. Reset pulse width vs. VCC. 85°C 25°C -40°C 0 500 1000 1500 2000 2500 1.5 2 2.5 3 3.5 4 4.5 5 5.5 VCC (V) Pulsewidth (ns)343 2545T–AVR–05/11 ATmega48/88/168 31. Register summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page (0xFF) Reserved – – – – – – – – (0xFE) Reserved – – – – – – – – (0xFD) Reserved – – – – – – – – (0xFC) Reserved – – – – – – – – (0xFB) Reserved – – – – – – – – (0xFA) Reserved – – – – – – – – (0xF9) Reserved – – – – – – – – (0xF8) Reserved – – – – – – – – (0xF7) Reserved – – – – – – – – (0xF6) Reserved – – – – – – – – (0xF5) Reserved – – – – – – – – (0xF4) Reserved – – – – – – – – (0xF3) Reserved – – – – – – – – (0xF2) Reserved – – – – – – – – (0xF1) Reserved – – – – – – – – (0xF0) Reserved – – – – – – – – (0xEF) Reserved – – – – – – – – (0xEE) Reserved – – – – – – – – (0xED) Reserved – – – – – – – – (0xEC) Reserved – – – – – – – – (0xEB) Reserved – – – – – – – – (0xEA) Reserved – – – – – – – – (0xE9) Reserved – – – – – – – – (0xE8) Reserved – – – – – – – – (0xE7) Reserved – – – – – – – – (0xE6) Reserved – – – – – – – – (0xE5) Reserved – – – – – – – – (0xE4) Reserved – – – – – – – – (0xE3) Reserved – – – – – – – – (0xE2) Reserved – – – – – – – – (0xE1) Reserved – – – – – – – – (0xE0) Reserved – – – – – – – – (0xDF) Reserved – – – – – – – – (0xDE) Reserved – – – – – – – – (0xDD) Reserved – – – – – – – – (0xDC) Reserved – – – – – – – – (0xDB) Reserved – – – – – – – – (0xDA) Reserved – – – – – – – – (0xD9) Reserved – – – – – – – – (0xD8) Reserved – – – – – – – – (0xD7) Reserved – – – – – – – – (0xD6) Reserved – – – – – – – – (0xD5) Reserved – – – – – – – – (0xD4) Reserved – – – – – – – – (0xD3) Reserved – – – – – – – – (0xD2) Reserved – – – – – – – – (0xD1) Reserved – – – – – – – – (0xD0) Reserved – – – – – – – – (0xCF) Reserved – – – – – – – – (0xCE) Reserved – – – – – – – – (0xCD) Reserved – – – – – – – – (0xCC) Reserved – – – – – – – – (0xCB) Reserved – – – – – – – – (0xCA) Reserved – – – – – – – – (0xC9) Reserved – – – – – – – – (0xC8) Reserved – – – – – – – – (0xC7) Reserved – – – – – – – – (0xC6) UDR0 USART I/O data register 190 (0xC5) UBRR0H USART baud rate register high 194 (0xC4) UBRR0L USART baud rate register low 194 (0xC3) Reserved – – – – – – – – (0xC2) UCSR0C UMSEL01 UMSEL00 UPM01 UPM00 USBS0 UCSZ01 /UDORD0 UCSZ00 / UCPHA0 UCPOL0 192/207 (0xC1) UCSR0B RXCIE0 TXCIE0 UDRIE0 RXEN0 TXEN0 UCSZ02 RXB80 TXB80 191 (0xC0) UCSR0A RXC0 TXC0 UDRE0 FE0 DOR0 UPE0 U2X0 MPCM0 190344 2545T–AVR–05/11 ATmega48/88/168 (0xBF) Reserved – – – – – – – – (0xBE) Reserved – – – – – – – – (0xBD) TWAMR TWAM6 TWAM5 TWAM4 TWAM3 TWAM2 TWAM1 TWAM0 – 239 (0xBC) TWCR TWINT TWEA TWSTA TWSTO TWWC TWEN – TWIE 236 (0xBB) TWDR 2-wire serial interface data register 238 (0xBA) TWAR TWA6 TWA5 TWA4 TWA3 TWA2 TWA1 TWA0 TWGCE 239 (0xB9) TWSR TWS7 TWS6 TWS5 TWS4 TWS3 – TWPS1 TWPS0 238 (0xB8) TWBR 2-wire serial interface bit rate register 236 (0xB7) Reserved – – – – – – – (0xB6) ASSR – EXCLK AS2 TCN2UB OCR2AUB OCR2BUB TCR2AUB TCR2BUB 159 (0xB5) Reserved – – – – – – – – (0xB4) OCR2B Timer/Counter2 output compare register B 158 (0xB3) OCR2A Timer/Counter2 output compare register A 157 (0xB2) TCNT2 Timer/Counter2 (8-bit) 157 (0xB1) TCCR2B FOC2A FOC2B – – WGM22 CS22 CS21 CS20 156 (0xB0) TCCR2A COM2A1 COM2A0 COM2B1 COM2B0 – – WGM21 WGM20 153 (0xAF) Reserved – – – – – – – – (0xAE) Reserved – – – – – – – – (0xAD) Reserved – – – – – – – – (0xAC) Reserved – – – – – – – – (0xAB) Reserved – – – – – – – – (0xAA) Reserved – – – – – – – – (0xA9) Reserved – – – – – – – – (0xA8) Reserved – – – – – – – – (0xA7) Reserved – – – – – – – – (0xA6) Reserved – – – – – – – – (0xA5) Reserved – – – – – – – – (0xA4) Reserved – – – – – – – – (0xA3) Reserved – – – – – – – – (0xA2) Reserved – – – – – – – – (0xA1) Reserved – – – – – – – – (0xA0) Reserved – – – – – – – – (0x9F) Reserved – – – – – – – – (0x9E) Reserved – – – – – – – – (0x9D) Reserved – – – – – – – – (0x9C) Reserved – – – – – – – – (0x9B) Reserved – – – – – – – – (0x9A) Reserved – – – – – – – – (0x99) Reserved – – – – – – – – (0x98) Reserved – – – – – – – – (0x97) Reserved – – – – – – – – (0x96) Reserved – – – – – – – – (0x95) Reserved – – – – – – – – (0x94) Reserved – – – – – – – – (0x93) Reserved – – – – – – – – (0x92) Reserved – – – – – – – – (0x91) Reserved – – – – – – – – (0x90) Reserved – – – – – – – – (0x8F) Reserved – – – – – – – – (0x8E) Reserved – – – – – – – – (0x8D) Reserved – – – – – – – – (0x8C) Reserved – – – – – – – – (0x8B) OCR1BH Timer/Counter1 - output compare register B high byte 134 (0x8A) OCR1BL Timer/Counter1 - output compare register B low byte 134 (0x89) OCR1AH Timer/Counter1 - output compare register A high byte 134 (0x88) OCR1AL Timer/Counter1 - output compare register A low byte 134 (0x87) ICR1H Timer/Counter1 - input capture register high byte 135 (0x86) ICR1L Timer/Counter1 - input capture register low byte 135 (0x85) TCNT1H Timer/Counter1 - counter register high byte 134 (0x84) TCNT1L Timer/Counter1 - counter register low byte 134 (0x83) Reserved – – – – – – – – (0x82) TCCR1C FOC1A FOC1B – – – – – – 133 (0x81) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 132 (0x80) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 – – WGM11 WGM10 130 (0x7F) DIDR1 – – – – – – AIN1D AIN0D 243 (0x7E) DIDR0 – – ADC5D ADC4D ADC3D ADC2D ADC1D ADC0D 259 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page345 2545T–AVR–05/11 ATmega48/88/168 (0x7D) Reserved – – – – – – – – (0x7C) ADMUX REFS1 REFS0 ADLAR – MUX3 MUX2 MUX1 MUX0 255 (0x7B) ADCSRB – ACME – – – ADTS2 ADTS1 ADTS0 258 (0x7A) ADCSRA ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 256 (0x79) ADCH ADC data register high byte 258 (0x78) ADCL ADC data register low byte 258 (0x77) Reserved – – – – – – – – (0x76) Reserved – – – – – – – – (0x75) Reserved – – – – – – – – (0x74) Reserved – – – – – – – – (0x73) Reserved – – – – – – – – (0x72) Reserved – – – – – – – – (0x71) Reserved – – – – – – – – (0x70) TIMSK2 – – – – – OCIE2B OCIE2A TOIE2 158 (0x6F) TIMSK1 – – ICIE1 – – OCIE1B OCIE1A TOIE1 135 (0x6E) TIMSK0 – – – – – OCIE0B OCIE0A TOIE0 106 (0x6D) PCMSK2 PCINT23 PCINT22 PCINT21 PCINT20 PCINT19 PCINT18 PCINT17 PCINT16 70 (0x6C) PCMSK1 – PCINT14 PCINT13 PCINT12 PCINT11 PCINT10 PCINT9 PCINT8 70 (0x6B) PCMSK0 PCINT7 PCINT6 PCINT5 PCINT4 PCINT3 PCINT2 PCINT1 PCINT0 70 (0x6A) Reserved – – – – – – – – (0x69) EICRA – – – – ISC11 ISC10 ISC01 ISC00 67 (0x68) PCICR – – – – – PCIE2 PCIE1 PCIE0 (0x67) Reserved – – – – – – – – (0x66) OSCCAL Oscillator calibration register 37 (0x65) Reserved – – – – – – – – (0x64) PRR PRTWI PRTIM2 PRTIM0 – PRTIM1 PRSPI PRUSART0 PRADC 41 (0x63) Reserved – – – – – – – – (0x62) Reserved – – – – – – – – (0x61) CLKPR CLKPCE – – – CLKPS3 CLKPS2 CLKPS1 CLKPS0 37 (0x60) WDTCSR WDIF WDIE WDP3 WDCE WDE WDP2 WDP1 WDP0 53 0x3F (0x5F) SREG I T H S V N Z C 11 0x3E (0x5E) SPH – – – – – (SP10) 5. SP9 SP8 13 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 13 0x3C (0x5C) Reserved – – – – – – – – 0x3B (0x5B) Reserved – – – – – – – – 0x3A (0x5A) Reserved – – – – – – – – 0x39 (0x59) Reserved – – – – – – – – 0x38 (0x58) Reserved – – – – – – – – 0x37 (0x57) SPMCSR SPMIE (RWWSB)5. – (RWWSRE)5. BLBSET PGWRT PGERS SELFPRGEN 283 0x36 (0x56) Reserved – – – – – – – – 0x35 (0x55) MCUCR – – – PUD – – IVSEL IVCE 0x34 (0x54) MCUSR – – – – WDRF BORF EXTRF PORF 0x33 (0x53) SMCR – – – – SM2 SM1 SM0 SE 39 0x32 (0x52) Reserved – – – – – – – – 0x31 (0x51) Reserved – – – – – – – – 0x30 (0x50) ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 242 0x2F (0x4F) Reserved – – – – – – – – 0x2E (0x4E) SPDR SPI data register 170 0x2D (0x4D) SPSR SPIF WCOL – – – – – SPI2X 169 0x2C (0x4C) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 168 0x2B (0x4B) GPIOR2 General purpose I/O register 2 26 0x2A (0x4A) GPIOR1 General purpose I/O register 1 26 0x29 (0x49) Reserved – – – – – – – – 0x28 (0x48) OCR0B Timer/Counter0 output compare register B 0x27 (0x47) OCR0A Timer/Counter0 output compare register A 0x26 (0x46) TCNT0 Timer/Counter0 (8-bit) 0x25 (0x45) TCCR0B FOC0A FOC0B – – WGM02 CS02 CS01 CS00 0x24 (0x44) TCCR0A COM0A1 COM0A0 COM0B1 COM0B0 – – WGM01 WGM00 0x23 (0x43) GTCCR TSM – – – – – PSRASY PSRSYNC 139/160 0x22 (0x42) EEARH (EEPROM address register high byte) 5. 22 0x21 (0x41) EEARL EEPROM address register low byte 22 0x20 (0x40) EEDR EEPROM data register 22 0x1F (0x3F) EECR – – EEPM1 EEPM0 EERIE EEMPE EEPE EERE 22 0x1E (0x3E) GPIOR0 General purpose I/O register 0 26 0x1D (0x3D) EIMSK – – – – – – INT1 INT0 68 0x1C (0x3C) EIFR – – – – – – INTF1 INTF0 68 Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page346 2545T–AVR–05/11 ATmega48/88/168 Note: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written. 2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. 3. Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operate on the specified bit, and can therefore be used on registers containing such Status Flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only. 4. When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing I/O Registers as data space using LD and ST instructions, 0x20 must be added to these addresses. The Atmel ATmega48/88/168 is a complex microcontroller with more peripheral units than can be supported within the 64 location reserved in Opcode for the IN and OUT instructions. For the Extended I/O space from 0x60 - 0xFF in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used. 5. Only valid for ATmega88/168 0x1B (0x3B) PCIFR – – – – – PCIF2 PCIF1 PCIF0 0x1A (0x3A) Reserved – – – – – – – – 0x19 (0x39) Reserved – – – – – – – – 0x18 (0x38) Reserved – – – – – – – – 0x17 (0x37) TIFR2 – – – – – OCF2B OCF2A TOV2 158 0x16 (0x36) TIFR1 – – ICF1 – – OCF1B OCF1A TOV1 136 0x15 (0x35) TIFR0 – – – – – OCF0B OCF0A TOV0 0x14 (0x34) Reserved – – – – – – – – 0x13 (0x33) Reserved – – – – – – – – 0x12 (0x32) Reserved – – – – – – – – 0x11 (0x31) Reserved – – – – – – – – 0x10 (0x30) Reserved – – – – – – – – 0x0F (0x2F) Reserved – – – – – – – – 0x0E (0x2E) Reserved – – – – – – – – 0x0D (0x2D) Reserved – – – – – – – – 0x0C (0x2C) Reserved – – – – – – – – 0x0B (0x2B) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 88 0x0A (0x2A) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 88 0x09 (0x29) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 88 0x08 (0x28) PORTC – PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 87 0x07 (0x27) DDRC – DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 87 0x06 (0x26) PINC – PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 87 0x05 (0x25) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 87 0x04 (0x24) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 87 0x03 (0x23) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 87 0x02 (0x22) Reserved – – – – – – – – 0x01 (0x21) Reserved – – – – – – – – 0x0 (0x20) Reserved – – – – – – – – Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page347 2545T–AVR–05/11 ATmega48/88/168 32. Instruction set summary Mnemonics Operands Description Operation Flags #Clocks ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two registers Rd ← Rd + Rr Z, C, N, V, H 1 ADC Rd, Rr Add with carry two registers Rd ← Rd + Rr + C Z, C, N, V, H 1 ADIW Rdl,K Add immediate to word Rdh:Rdl ← Rdh:Rdl + K Z, C, N, V, S 2 SUB Rd, Rr Subtract two registers Rd ← Rd - Rr Z, C, N, V, H 1 SUBI Rd, K Subtract constant from register Rd ← Rd - K Z, C, N, V, H 1 SBC Rd, Rr Subtract with carry two registers Rd ← Rd - Rr - C Z, C, N, V, H 1 SBCI Rd, K Subtract with carry constant from reg. Rd ← Rd - K - C Z, C, N, V, H 1 SBIW Rdl,K Subtract immediate from Word Rdh:Rdl ← Rdh:Rdl - K Z, C, N, V, S 2 AND Rd, Rr Logical AND registers Rd ← Rd • Rr Z, N, V 1 ANDI Rd, K Logical AND register and constant Rd ← Rd • K Z, N, V 1 OR Rd, Rr Logical OR registers Rd ← Rd v Rr Z, N, V 1 ORI Rd, K Logical OR register and constant Rd ← Rd v K Z, N, V 1 EOR Rd, Rr Exclusive OR registers Rd ← Rd ⊕ Rr Z, N, V 1 COM Rd One’s complement Rd ← 0xFF − Rd Z, C, N, V 1 NEG Rd Two’s complement Rd ← 0x00 − Rd Z, C, N, V, H 1 SBR Rd,K Set bit(s) in register Rd ← Rd v K Z, N, V 1 CBR Rd,K Clear bit(s) in register Rd ← Rd • (0xFF - K) Z, N, V 1 INC Rd Increment Rd ← Rd + 1 Z, N, V 1 DEC Rd Decrement Rd ← Rd − 1 Z, N, V 1 TST Rd Test for zero or minus Rd ← Rd • Rd Z, N, V 1 CLR Rd Clear register Rd ← Rd ⊕ Rd Z, N, V 1 SER Rd Set register Rd ← 0xFF None 1 MUL Rd, Rr Multiply unsigned R1:R0 ← Rd x Rr Z, C 2 MULS Rd, Rr Multiply signed R1:R0 ← Rd x Rr Z, C 2 MULSU Rd, Rr Multiply signed with unsigned R1:R0 ← Rd x Rr Z, C 2 FMUL Rd, Rr Fractional multiply unsigned R1:R0 ← (Rd x Rr) << 1 Z, C 2 FMULS Rd, Rr Fractional multiply signed R1:R0 ← (Rd x Rr) << 1 Z, C 2 FMULSU Rd, Rr Fractional multiply signed with unsigned R1:R0 ← (Rd x Rr) << 1 Z, C 2 BRANCH INSTRUCTIONS RJMP k Relative jump PC ← PC + k + 1 None 2 IJMP Indirect jump to (Z) PC ← Z None 2 JMP(1) k Direct jump PC ← k None 3 RCALL k Relative subroutine call PC ← PC + k + 1 None 3 ICALL Indirect call to (Z) PC ← Z None 3 CALL(1) k Direct subroutine call PC ← k None 4 RET Subroutine return PC ← STACK None 4 RETI Interrupt return PC ← STACK I 4 CPSE Rd,Rr Compare, skip if equal if (Rd = Rr) PC ← PC + 2 or 3 None 1/2/3 CP Rd,Rr Compare Rd − Rr Z, N, V, C, H 1 CPC Rd,Rr Compare with carry Rd − Rr − C Z, N, V, C, H 1 CPI Rd,K Compare register with immediate Rd − K Z, N, V, C, H 1 SBRC Rr, b Skip if bit in register cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBRS Rr, b Skip if bit in register is set if (Rr(b)=1) PC ← PC + 2 or 3 None 1/2/3 SBIC P, b Skip if bit in I/O register cleared if (P(b)=0) PC ← PC + 2 or 3 None 1/2/3 SBIS P, b Skip if bit in I/O register is set if (P(b)=1) PC ← PC + 2 or 3 None 1/2/3 BRBS s, k Branch if status flag set if (SREG(s) = 1) then PC←PC+k + 1 None 1/2 BRBC s, k Branch if status flag cleared if (SREG(s) = 0) then PC←PC+k + 1 None 1/2 BREQ k Branch if equal if (Z = 1) then PC ← PC + k + 1 None 1/2 BRNE k Branch if not equal if (Z = 0) then PC ← PC + k + 1 None 1/2 BRCS k Branch if carry set if (C = 1) then PC ← PC + k + 1 None 1/2 BRCC k Branch if carry cleared if (C = 0) then PC ← PC + k + 1 None 1/2 BRSH k Branch if same or higher if (C = 0) then PC ← PC + k + 1 None 1/2 BRLO k Branch if lower if (C = 1) then PC ← PC + k + 1 None 1/2 BRMI k Branch if minus if (N = 1) then PC ← PC + k + 1 None 1/2 BRPL k Branch if plus if (N = 0) then PC ← PC + k + 1 None 1/2 BRGE k Branch if greater or equal, signed if (N ⊕ V= 0) then PC ← PC + k + 1 None 1/2 BRLT k Branch if less than zero, signed if (N ⊕ V= 1) then PC ← PC + k + 1 None 1/2 BRHS k Branch if half carry flag set if (H = 1) then PC ← PC + k + 1 None 1/2 BRHC k Branch if half carry flag cleared if (H = 0) then PC ← PC + k + 1 None 1/2 BRTS k Branch if T flag set if (T = 1) then PC ← PC + k + 1 None 1/2 BRTC k Branch if T flag cleared if (T = 0) then PC ← PC + k + 1 None 1/2 BRVS k Branch if overflow flag is set if (V = 1) then PC ← PC + k + 1 None 1/2 BRVC k Branch if overflow flag is cleared if (V = 0) then PC ← PC + k + 1 None 1/2348 2545T–AVR–05/11 ATmega48/88/168 BRIE k Branch if interrupt enabled if ( I = 1) then PC ← PC + k + 1 None 1/2 BRID k Branch if interrupt disabled if ( I = 0) then PC ← PC + k + 1 None 1/2 BIT AND BIT-TEST INSTRUCTIONS SBI P,b Set bit in I/O register I/O(P,b) ← 1 None 2 CBI P,b Clear bit in I/O register I/O(P,b) ← 0 None 2 LSL Rd Logical shift left Rd(n+1) ← Rd(n), Rd(0) ← 0 Z, C, N, V 1 LSR Rd Logical shift right Rd(n) ← Rd(n+1), Rd(7) ← 0 Z, C, N, V 1 ROL Rd Rotate left through carry Rd(0)←C,Rd(n+1)← Rd(n),C←Rd(7) Z, C, N, V 1 ROR Rd Rotate right through carry Rd(7)←C,Rd(n)← Rd(n+1),C←Rd(0) Z, C, N, V 1 ASR Rd Arithmetic shift right Rd(n) ← Rd(n+1), n=0..6 Z, C, N, V 1 SWAP Rd Swap nibbles Rd(3..0)←Rd(7..4),Rd(7..4)←Rd(3..0) None 1 BSET s Flag set SREG(s) ← 1 SREG(s) 1 BCLR s Flag clear SREG(s) ← 0 SREG(s) 1 BST Rr, b Bit store from register to T T ← Rr(b) T 1 BLD Rd, b Bit load from T to register Rd(b) ← T None 1 SEC Set carry C ← 1 C1 CLC Clear carry C ← 0 C 1 SEN Set negative flag N ← 1 N1 CLN Clear negative flag N ← 0 N 1 SEZ Set zero flag Z ← 1 Z1 CLZ Clear zero flag Z ← 0 Z 1 SEI Global interrupt enable I ← 1 I1 CLI Global interrupt disable I ← 0 I 1 SES Set signed test flag S ← 1 S1 CLS Clear signed test flag S ← 0 S 1 SEV Set Twos complement overflow V ← 1 V1 CLV Clear Twos complement overflow V ← 0 V 1 SET Set T in SREG T ← 1 T1 CLT Clear T in SREG T ← 0 T 1 SEH Set half carry flag in SREG H ← 1 H1 CLH Clear half carry flag in SREG H ← 0 H 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move between registers Rd ← Rr None 1 MOVW Rd, Rr Copy register Word Rd+1:Rd ← Rr+1:Rr None 1 LDI Rd, K Load immediate Rd ← K None 1 LD Rd, X Load indirect Rd ← (X) None 2 LD Rd, X+ Load indirect and post-inc. Rd ← (X), X ← X + 1 None 2 LD Rd, - X Load indirect and pre-dec. X ← X - 1, Rd ← (X) None 2 LD Rd, Y Load indirect Rd ← (Y) None 2 LD Rd, Y+ Load indirect and post-inc. Rd ← (Y), Y ← Y + 1 None 2 LD Rd, - Y Load indirect and pre-dec. Y ← Y - 1, Rd ← (Y) None 2 LDD Rd,Y+q Load indirect with displacement Rd ← (Y + q) None 2 LD Rd, Z Load indirect Rd ← (Z) None 2 LD Rd, Z+ Load indirect and post-inc. Rd ← (Z), Z ← Z+1 None 2 LD Rd, -Z Load indirect and pre-dec. Z ← Z - 1, Rd ← (Z) None 2 LDD Rd, Z+q Load indirect with displacement Rd ← (Z + q) None 2 LDS Rd, k Load direct from SRAM Rd ← (k) None 2 ST X, Rr Store indirect (X) ← Rr None 2 ST X+, Rr Store indirect and post-inc. (X) ← Rr, X ← X + 1 None 2 ST - X, Rr Store indirect and pre-dec. X ← X - 1, (X) ← Rr None 2 ST Y, Rr Store indirect (Y) ← Rr None 2 ST Y+, Rr Store indirect and post-inc. (Y) ← Rr, Y ← Y + 1 None 2 ST - Y, Rr Store indirect and pre-dec. Y ← Y - 1, (Y) ← Rr None 2 STD Y+q,Rr Store indirect with displacement (Y + q) ← Rr None 2 ST Z, Rr Store indirect (Z) ← Rr None 2 ST Z+, Rr Store indirect and post-inc. (Z) ← Rr, Z ← Z + 1 None 2 ST -Z, Rr Store indirect and pre-dec. Z ← Z - 1, (Z) ← Rr None 2 STD Z+q,Rr Store indirect with displacement (Z + q) ← Rr None 2 STS k, Rr Store direct to SRAM (k) ← Rr None 2 LPM Load program memory R0 ← (Z) None 3 LPM Rd, Z Load program memory Rd ← (Z) None 3 LPM Rd, Z+ Load program memory and post-inc Rd ← (Z), Z ← Z+1 None 3 SPM Store program memory (Z) ← R1:R0 None - IN Rd, P In port Rd ← P None 1 OUT P, Rr Out port P ← Rr None 1 PUSH Rr Push register on stack STACK ← Rr None 2 Mnemonics Operands Description Operation Flags #Clocks349 2545T–AVR–05/11 ATmega48/88/168 Note: 1. These instructions are only available in Atmel ATmega168. POP Rd Pop register from stack Rd ← STACK None 2 MCU CONTROL INSTRUCTIONS NOP No operation None 1 SLEEP Sleep (See specific descr. for sleep function) None 1 WDR Watchdog reset (See specific descr. for WDR/timer) None 1 BREAK Break For on-chip debug only None N/A Mnemonics Operands Description Operation Flags #Clocks350 2545T–AVR–05/11 ATmega48/88/168 33. Ordering information 33.1 Atmel ATmega48 Note: 1. This device can also be supplied in wafer form. Please contact your local Atmel sales office for detailed ordering information and minimum quantities. 2. Pb-free packaging alternative, complies to the European Directive for Restriction of Hazardous Substances (RoHS directive). Also Halide free and fully Green. 3. See Figure 29-1 on page 305 and Figure 29-2 on page 305. 4. NiPdAu lead finish. 5. Tape & Reel. Speed (MHz) Power supply Ordering code(2) Package(1) Operational range 10(3) 1.8V - 5.5V ATmega48V-10AUR(5) ATmega48V-10MUR(5) ATmega48V-10AU ATmega48V-10MMU ATmega48V-10MMUR(5) ATmega48V-10MMH(4) ATmega48V-10MMHR(4)(5) ATmega48V-10MU ATmega48V-10PU