Features • High-performance, Low-power 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 16 MHz – On-chip 2-cycle Multiplier High Endurance Non-volatile Memory segments – 8K Bytes of In-System Self-programmable Flash program memory – 512 Bytes EEPROM – 1K Byte 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 – 2.7 - 5.5V for ATmega8A Speed Grades – 0 - 16 MHz for ATmega8A Power Consumption at 4 Mhz, 3V, 25°C – Active: 3.6 mA – Idle Mode: 1.0 mA – Power-down Mode: 0.5 µA 8-bit with 8K Bytes In-System Programmable Flash ATmega8A Summary 8159CS–AVR–07/09 ATmega8A 1. Pin Configurations Figure 1-1. Pinout ATmega8A PDIP (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 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 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) 32 31 30 29 28 27 26 25 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 24 23 22 21 20 19 18 17 PC1 (ADC1) PC0 (ADC0) ADC7 GND AREF ADC6 AVCC PB5 (SCK) 24 23 22 21 20 19 18 17 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 9 10 11 12 13 14 15 16 (INT1) PD3 (XCK/T0) PD4 GND VCC GND VCC (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 32 31 30 29 28 27 26 25 PD2 (INT0) PD1 (TXD) PD0 (RXD) PC6 (RESET) PC5 (ADC5/SCL) PC4 (ADC4/SDA) PC3 (ADC3) PC2 (ADC2) MLF Top View 1 2 3 4 5 6 7 8 (T1) PD5 (AIN0) PD6 (AIN1) PD7 (ICP1) PB0 (OC1A) PB1 (SS/OC1B) PB2 (MOSI/OC2) PB3 (MISO) PB4 9 10 11 12 13 14 15 16 (INT1) PD3 (XCK/T0) PD4 GND VCC GND VCC (XTAL1/TOSC1) PB6 (XTAL2/TOSC2) PB7 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. 2 8159CS–AVR–07/09 ATmega8A 2. Overview The 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 XTAL1 RESET PC0 - PC6 PB0 - PB7 VCC XTAL2 GND PORTC DRIVERS/BUFFERS PORTB DRIVERS/BUFFERS PORTC DIGITAL INTERFACE PORTB DIGITAL INTERFACE MUX & ADC ADC INTERFACE PROGRAM COUNTER STACK POINTER PROGRAM FLASH SRAM TWI AGND AREF INSTRUCTION REGISTER GENERAL PURPOSE REGISTERS TIMERS/ COUNTERS OSCILLATOR INTERNAL OSCILLATOR WATCHDOG TIMER OSCILLATOR X INSTRUCTION DECODER Y MCU CTRL. & TIMING Z CONTROL LINES ALU INTERRUPT UNIT AVR CPU STATUS REGISTER EEPROM PROGRAMMING LOGIC SPI USART + - COMP. INTERFACE PORTD DIGITAL INTERFACE PORTD DRIVERS/BUFFERS PD0 - PD7 3 8159CS–AVR–07/09 ATmega8A 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 ATmega8A provides the following features: 8K bytes of In-System Programmable Flash with Read-While-Write 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 ATmega8A 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 2.2.1 Pin Descriptions 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. 4 8159CS–AVR–07/09 ATmega8A 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 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 25-3 on page 247. Shorter pulses are not guaranteed to generate a Reset. The various special features of Port C are elaborated on page 61. 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 63. 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 25-3 on page 247. 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. 5 8159CS–AVR–07/09 ATmega8A 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. 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. 6 8159CS–AVR–07/09 ATmega8A 5. Register Summary Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0x3F (0x5F) SREG I T H S V N Z C Page 8 0x3E (0x5E) SPH – – – – – SP10 SP9 SP8 11 0x3D (0x5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 11 0x3C (0x5C) Reserved 0x3B (0x5B) GICR INT1 INT0 – – – – IVSEL IVCE 48, 68 0x3A (0x5A) GIFR INTF1 INTF0 – – – – – – 69 0x39 (0x59) TIMSK OCIE2 TOIE2 TICIE1 OCIE1A OCIE1B TOIE1 – TOIE0 73, 104, 124 74, 104, 104 0x38 (0x58) TIFR OCF2 TOV2 ICF1 OCF1A OCF1B TOV1 – TOV0 0x37 (0x57) SPMCR SPMIE RWWSB – RWWSRE BLBSET PGWRT PGERS SPMEN 224 0x36 (0x56) TWCR TWINT TWEA TWSTA TWSTO TWWC TWEN – TWIE 191 0x35 (0x55) MCUCR SE SM2 SM1 SM0 ISC11 ISC10 ISC01 ISC00 36, 67 0x34 (0x54) MCUCSR – – – – WDRF BORF EXTRF PORF 43 0x33 (0x53) TCCR0 – – – – – CS02 CS01 CS00 73 0x32 (0x52) TCNT0 Timer/Counter0 (8 Bits) 0x31 (0x51) OSCCAL Oscillator Calibration Register 0x30 (0x50) SFIOR – – – – 73 31 ACME PUD PSR2 PSR10 57, 77, 125, 196 0x2F (0x4F) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 FOC1A FOC1B WGM11 WGM10 99 0x2E (0x4E) TCCR1B ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10 101 0x2D (0x4D) TCNT1H Timer/Counter1 – Counter Register High byte 102 0x2C (0x4C) TCNT1L 102 0x2B (0x4B) OCR1AH Timer/Counter1 – Counter Register Low byte Timer/Counter1 – Output Compare Register A High byte 103 0x2A (0x4A) OCR1AL Timer/Counter1 – Output Compare Register A Low byte 103 0x29 (0x49) OCR1BH Timer/Counter1 – Output Compare Register B High byte 103 0x28 (0x48) OCR1BL Timer/Counter1 – Output Compare Register B Low byte 103 0x27 (0x47) ICR1H Timer/Counter1 – Input Capture Register High byte 103 0x26 (0x46) ICR1L Timer/Counter1 – Input Capture Register Low byte 103 0x25 (0x45) TCCR2 0x24 (0x44) TCNT2 0x23 (0x43) OCR2 FOC2 WGM20 COM21 COM20 WGM21 CS22 CS21 CS20 Timer/Counter2 (8 Bits) Timer/Counter2 Output Compare Register 123 123 0x22 (0x42) ASSR – – – – AS2 TCN2UB OCR2UB TCR2UB 0x21 (0x41) WDTCR – – – WDCE WDE WDP2 WDP1 WDP0 UBRRH URSEL – – – 0x20(1) (0x40)(1) 121 UBRR[11:8] 123 43 160 UCSRC URSEL UMSEL UPM1 UPM0 USBS UCSZ1 UCSZ0 UCPOL 0x1F (0x3F) EEARH – – – – – – – EEAR8 19 0x1E (0x3E) EEARL EEAR7 EEAR6 EEAR5 EEAR4 EEAR3 EEAR2 EEAR1 EEAR0 19 0x1D (0x3D) EEDR 0x1C (0x3C) EECR – – – – EERIE EEMWE EEWE EERE 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 0x0F (0x2F) SPDR EEPROM Data Register 159 19 SPI Data Register 19 66 135 0x0E (0x2E) SPSR SPIF WCOL – – – – – SPI2X 134 0x0D (0x2D) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 133 0x0C (0x2C) UDR 0x0B (0x2B) UCSRA RXC TXC UDRE 0x0A (0x2A) UCSRB RXCIE TXCIE UDRIE 0x09 (0x29) UBRRL 0x08 (0x28) ACSR ACD ACBG ACO USART I/O Data Register 156 FE DOR PE U2X MPCM 157 RXEN TXEN UCSZ2 RXB8 TXB8 158 ACIC ACIS1 ACIS0 196 USART Baud Rate Register Low byte ACI ACIE 160 0x07 (0x27) ADMUX REFS1 REFS0 ADLAR – MUX3 MUX2 MUX1 MUX0 208 0x06 (0x26) ADCSRA ADEN ADSC ADFR ADIF ADIE ADPS2 ADPS1 ADPS0 209 0x05 (0x25) ADCH ADC Data Register High byte 210 0x04 (0x24) ADCL ADC Data Register Low byte 210 0x03 (0x23) TWDR 0x02 (0x22) TWAR Two-wire Serial Interface Data Register TWA6 TWA5 TWA4 TWA3 TWA2 193 TWA1 TWA0 TWGCE 194 7 8159CS–AVR–07/09 ATmega8A 5. Register Summary (Continued) Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page 0x01 (0x21) TWSR TWS7 TWS6 TWS5 TWS4 TWS3 – TWPS1 TWPS0 193 0x00 (0x20) TWBR Note: Two-wire Serial Interface Bit Rate Register 191 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. 8 8159CS–AVR–07/09 ATmega8A 6. 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 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 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 1 AND Rd, Rr Logical AND Registers Rd ← Rd • Rr Z,N,V 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) << Z,C 2 FMULS Rd, Rr Fractional Multiply Signed Z,C 2 FMULSU Rd, Rr Fractional Multiply Signed with Unsigned 1 R1:R0 ← (Rd x Rr) << 1 R1:R0 ← (Rd x Rr) << 1 Z,C 2 Relative Jump PC ← PC + k + 1 None 2 Indirect Jump to (Z) PC ← Z None 2 BRANCH INSTRUCTIONS RJMP k IJMP 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 if (Rd = Rr) PC ← PC + 2 or 3 None RCALL k 4 CPSE Rd,Rr Compare, Skip if Equal 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 SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1 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 Mnemonics Operands Description Operation Flags 1/2 #Clocks 9 8159CS–AVR–07/09 ATmega8A 6. Instruction Set Summary (Continued) 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 None 1 None 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr Move Between Registers MOVW Rd, Rr Copy Register Word Rd ← Rr Rd+1:Rd ← Rr+1:Rr 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 2 LD Rd, Y Load Indirect Rd ← (Y) None 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 2 LDS Rd, k Load Direct from SRAM Rd ← (k) None 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 Load Program Memory R0 ← (Z) None 3 LPM 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 Store Program Memory (Z) ← R1:R0 None - In Port Rd ← P None 1 SPM IN Rd, P 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 1 SEC Set Carry C←1 C 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 1 SES Set Signed Test Flag S←1 S CLS Clear Signed Test Flag S←0 S 1 SEV Set Twos Complement Overflow. V←1 V 1 CLV Clear Twos Complement Overflow V←0 V 1 SET Set T in SREG T←1 T Mnemonics Operands Description Operation 1 Flags #Clocks 10 8159CS–AVR–07/09 ATmega8A 6. Instruction Set Summary (Continued) CLT Clear T in SREG T←0 T 1 SEH CLH Set Half Carry Flag in SREG Clear Half Carry Flag in SREG H←1 H←0 H H 1 1 MCU CONTROL INSTRUCTIONS NOP SLEEP WDR No Operation Sleep Watchdog Reset (see specific descr. for Sleep function) (see specific descr. for WDR/timer) None None None 1 1 1 11 8159CS–AVR–07/09 ATmega8A 7. Ordering Information Speed (MHz) Power Supply (V) Ordering Code (2) 16 Notes: 2.7 - 5.5 ATmega8A-AU ATmega8A-PU(2) ATmega8A-MU(2) Package(1) 32A 28P3 32M1-A Operation Range Industrial (-40°C to 85°C) 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. Package Type 32A 32-lead, Thin (1.0 mm) 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) 12 8159CS–AVR–07/09 ATmega8A 8. Packaging Information 8.1 32A PIN 1 B PIN 1 IDENTIFIER E1 e E D1 D C 0˚~7˚ A1 A2 A L COMMON DIMENSIONS (Unit of Measure = mm) 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 0.25 mm per side. Dimensions D1 and E1 are maximum plastic body size dimensions including mold mismatch. 3. Lead coplanarity is 0.10 mm maximum. SYMBOL MIN NOM MAX 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 E 8.75 9.00 9.25 E1 6.90 7.00 7.10 B 0.30 – 0.45 C 0.09 – 0.20 L 0.45 – 0.75 e NOTE Note 2 Note 2 0.80 TYP 10/5/2001 R 2325 Orchard Parkway San Jose, CA 95131 TITLE 32A, 32-lead, 7 x 7 mm Body Size, 1.0 mm Body Thickness, 0.8 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP) DRAWING NO. REV. 32A B 13 8159CS–AVR–07/09 ATmega8A 8.2 28P3 D PIN 1 E1 A SEATING PLANE L B2 B1 A1 B (4 PLACES) 0º ~ 15º REF e E C COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL eB Note: 1. Dimensions D and E1 do not include mold Flash or Protrusion. Mold Flash or Protrusion shall not exceed 0.25 mm (0.010"). A MIN – NOM MAX – 4.5724 A1 0.508 – – D 34.544 – 34.798 E 7.620 – 8.255 E1 7.112 – 7.493 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 NOTE Note 1 Note 1 2.540 TYP 09/28/01 R 2325 Orchard Parkway San Jose, CA 95131 TITLE 28P3, 28-lead (0.300"/7.62 mm Wide) Plastic Dual Inline Package (PDIP) DRAWING NO. 28P3 REV. B 14 8159CS–AVR–07/09 ATmega8A 32M1-A D D1 1 2 3 0 Pin 1 ID E1 SIDE VIEW E TOP VIEW A3 A2 A1 A K 0.08 C P D2 1 2 3 P Pin #1 Notch (0.20 R) K e SYMBOL MIN NOM MAX A 0.80 0.90 1.00 A1 – 0.02 0.05 A2 – 0.65 1.00 A3 E2 b COMMON DIMENSIONS (Unit of Measure = mm) L BOTTOM VIEW 0.20 REF b 0.18 0.23 0.30 D 4.90 5.00 5.10 D1 4.70 4.75 4.80 D2 2.95 3.10 3.25 5.10 E 4.90 5.00 E1 4.70 4.75 4.80 E2 2.95 3.10 3.25 e Note: JEDEC Standard MO-220, Fig. 2 (Anvil Singulation), VHHD-2. NOTE 0.50 BSC L 0.30 0.40 0.50 0.60 12o P – – 0 – – K 0.20 – – 5/25/06 R 2325 Orchard Parkway San Jose, CA 95131 TITLE 32M1-A, 32-pad, 5 x 5 x 1.0 mm Body, Lead Pitch 0.50 mm, 3.10 mm Exposed Pad, Micro Lead Frame Package (MLF) DRAWING NO. 32M1-A REV. E 15 8159CS–AVR–07/09 ATmega8A 9. Errata The revision letter in this section refers to the revision of the ATmega8A device. 9.1 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 32 KHz 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 32 KHz 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 32 KHz 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). 16 8159CS–AVR–07/09 ATmega8A 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. 17 8159CS–AVR–07/09 ATmega8A 10. 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. 10.1 10.2 10.3 Rev.8159C – 07/09 1. Updated “Errata” on page 298. 2. Updated the last page with Atmel’s new addresses. Rev.8159BS – 05/09 1. Updated “System and Reset Characteristics” on page 247 with new BODLEVEL values 2. Updated “ADC Characteristics” on page 251 with new VINT values. 3. Updated “Typical Characteristics” view. 4. Updated “Errata” on page 298. ATmega8A, rev L. 5. Created a new Table Of Contents. Rev.8159AS – 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” on page 244. – Updated “DC Characteristics” on page 244 with new VOL Max (0.9V and 0.6V) and typical value for ICC. – Added “Speed Grades” on page 246. – Added a new sub section “System and Reset Characteristics” on page 247. – Updated “System and Reset Characteristics” on page 247 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” on page 252. – New “Ordering Information” on page 294. 18 8159CS–AVR–07/09 Headquarters International Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Atmel Asia 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 Europe Le Krebs 8, Rue Jean-Pierre Timbaud BP 309 78054 Saint-Quentin-enYvelines Cedex France Tel: (33) 1-30-60-70-00 Fax: (33) 1-30-60-71-11 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 Technical Support [email protected] Sales Contact www.atmel.com/contacts Product Contact Web Site www.atmel.com Literature Requests www.atmel.com/literature Disclaimer: The information in this document is provided in connection with Atmel products. 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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. © 2009 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. 8159CS–AVR–07/09