ATMEGA8-16MU - Atmel - Pdf.Support

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 16 MIPS 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

with 8KBytes In-

System

Programmable

Flash

ATmega8

ATmega8L

Summary

Rev. 2486ZS–AVR–02/11

2486ZS–AVR–02/11

ATmega8(L)

Configurations

(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)

TQFP Top View

(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

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.

2486ZS–AVR–02/11

ATmega8(L)

Overview The 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 1 MIPS per MHz, allowing the system designer to optimize power consumption ver-

sus processing speed.

Block Diagram Figure 1. Block Diagram

INTERNAL

OSCILLATOR

WATCHDOG

TIMER

MCU CTRL.

& TIMING

OSCILLATOR

TIMERS/

COUNTERS

INTERRUPT

UNIT

STACK

POINTER

EEPROM

SRAM

STATUS

USART

PROGRAM

COUNTER

PROGRAM

FLASH

INSTRUCTION

DECODER

PROGRAMMING

LOGIC SPI

ADC

INTERFACE

COMP.

INTERFACE

PORTC DRIVERS/BUFFERS

PORTC DIGITAL INTERFACE

GENERAL

PURPOSE

REGISTERS

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

RESET

2486ZS–AVR–02/11

ATmega8(L)

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 con-

ventional 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 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 func-

tions 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 sleep-

ing. 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 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.

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 Maxi-

mum values will be available after the device is characterized.

2486ZS–AVR–02/11

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 Oscil-

lator 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 char-

acteristics 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.

2486ZS–AVR–02/11

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 con-

nected 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.

2486ZS–AVR–02/11

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.

2486ZS–AVR–02/11

ATmega8(L)

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 –TOV072, 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 167

2486ZS–AVR–02/11

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

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page

2486ZS–AVR–02/11

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 ← ZNone3

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

2486ZS–AVR–02/11

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 ← KNone1

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 ← PNone1

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) ← 1None2

CBI P,b Clear Bit in I/O Register I/O(P,b) ← 0None2

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) ← TNone1

SEC Set Carry C ← 1C1

CLC Clear Carry C ← 0 C 1

SEN Set Negative Flag N ← 1N1

CLN Clear Negative Flag N ← 0 N 1

SEZ Set Zero Flag Z ← 1Z1

CLZ Clear Zero Flag Z ← 0 Z 1

SEI Global Interrupt Enable I ← 1I1

CLI Global Interrupt Disable I ← 0 I 1

SES Set Signed Test Flag S ← 1S1

CLS Clear Signed Test Flag S ← 0 S 1

SEV Set Twos Complement Overflow. V ← 1V1

CLV Clear Twos Complement Overflow V ← 0 V 1

SET Set T in SREG T ← 1T1

Instruction Set Summary (Continued)

2486ZS–AVR–02/11

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 ← 1H1

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

Instruction Set Summary (Continued)

2486ZS–AVR–02/11

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

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

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

28P3

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)

2486ZS–AVR–02/11

ATmega8(L)

Packaging Information

32A

2325 Orchard Parkway

San Jose, CA 95131

TITLE DRAWING NO.

REV.

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) C

32A

2010-10-20

PIN 1 IDENTIFIER

0°~7°

PIN 1

A1 A2 A

eE1 E

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.

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 NOTE

2486ZS–AVR–02/11

ATmega8(L)

28P3

2325 Orchard Parkway

San Jose, CA 95131

TITLE DRAWING NO.

REV.

28P3, 28-lead (0.300"/7.62 mm Wide) Plastic Dual

Inline Package (PDIP) B

28P3

09/28/01

REF

SEATING PLANE

0º ~ 15º

(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 0.25 mm (0.010").

2486ZS–AVR–02/11

ATmega8(L)

32M1-A

2325 Orchard Parkway

San Jose, CA 95131

TITLE DRAWING NO.

REV.

32M1-A, 32-pad, 5 x 5 x 1.0 mm Body, Lead Pitch 0.50 mm, E

32M1-A

5/25/06

3.10 mm Exposed Pad, Micro Lead Frame Package (MLF)

COMMON DIMENSIONS

(Unit of Measure = mm)

SYMBOL MIN NOM MAX NOTE

E1 E

0.08 C

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

D2 2.95 3.10 3.25

4.90 5.00 5.10

4.70 4.75 4.80

4.90 5.00 5.10

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

Pin 1 ID

Pin #1 Notch

(0.20 R)

K 0.20 – –

2486ZS–AVR–02/11

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, espe-

cially, 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. Cus-

tomers who want compatibility between Rev. G and older revisions, must ensure that

CKOPT is unprogrammed (CKOPT = 1).

2486ZS–AVR–02/11

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 reg-

ister triggers an unexpected EEPROM interrupt request.

Problem Fix / Workaround

Always use OUT or SBI to set EERE in EECR.

2486ZS–AVR–02/11

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.

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 13. Added Ording 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 289.

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 ICC typical values.

Changes from Rev.

2486S- 08/07 to

Rev. 2486T- 05/08

1. Updated Table 98 on page 233.

2. Updated “Ordering Information” on page 285.

- Commercial Ordering Code removed.

- No Pb-free packaging option removed.

2486ZS–AVR–02/11

ATmega8(L)

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 289.

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 289.

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.

8. Updated “Errata” on page 289.

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 1 MHz default value.

2486ZS–AVR–02/11

ATmega8(L)

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 285.

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.

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 Character-

istics” on page 235.

2486ZS–AVR–02/11

ATmega8(L)

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” on page 242.

4. Updated “Errata” on page 289.

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 “32 kHz

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.

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 286.

2486ZS–AVR–02/11

ATmega8(L)

Changes from Rev.

2486H-09/02 to

Rev. 2486I-12/02

1. Added errata for Rev D, E, and F on page 289.

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 Char-

acteristics,” 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 Pres-

caler,” on page 167.

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” on page 242.

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 8 MHz Oscillator selections. This is now added in the following sections:

Improved description of “Oscillator Calibration Register – OSCCAL” on page 31 and “Cali-

bration 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 Dis-

abled or if External Oscillators are Selected.

Added a note in section “Enter Programming Mode” on page 221.

2486ZS–AVR–02/11

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

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1-24-8 Shinkawa

Chuo-ku, Tokyo 104-0033

JAPAN

Tel: (+81)(3) 3523-3551

Fax: (+81)(3) 3523-7581

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