309
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
0x3E (0x5E)
SPH
–
SP10
SP9
SP8
0x3D (0x5D)
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
0x3C (0x5C)
Reserved
0x3B (0x5B)
GICR
INT1
INT0
–
IVSEL
IVCE
0x3A (0x5A)
GIFR
INTF1
INTF0
–
0x39 (0x59)
TIMSK
OCIE2
TOIE2
TICIE1
OCIE1A
OCIE1B
TOIE1
–
TOIE0
0x38 (0x58)
TIFR
OCF2
TOV2
ICF1
OCF1A
OCF1B
TOV1
–TOV0
0x37 (0x57)
SPMCR
SPMIE
RWWSB
–
RWWSRE
BLBSET
PGWRT
PGERS
SPMEN
0x36 (0x56)
TWCR
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
–TWIE
0x35 (0x55)
MCUCR
SE
SM2
SM1
SM0
ISC11
ISC10
ISC01
ISC00
0x34 (0x54)
MCUCSR
–
WDRF
BORF
EXTRF
PORF
0x33 (0x53)
TCCR0
–
CS02
CS01
CS00
0x32 (0x52)
TCNT0
Timer/Counter0 (8 Bits)
0x31 (0x51)
OSCCAL
Oscillator Calibration Register
0x30 (0x50)
SFIOR
–
ACME
PUD
PSR2
PSR10
0x2F (0x4F)
TCCR1A
COM1A1
COM1A0
COM1B1
COM1B0
FOC1A
FOC1B
WGM11
WGM10
0x2E (0x4E)
TCCR1B
ICNC1
ICES1
–
WGM13
WGM12
CS12
CS11
CS10
0x2D (0x4D)
TCNT1H
Timer/Counter1 – Counter Register High byte
0x2C (0x4C)
TCNT1L
Timer/Counter1 – Counter Register Low byte
0x2B (0x4B)
OCR1AH
Timer/Counter1 – Output Compare Register A High byte
0x2A (0x4A)
OCR1AL
Timer/Counter1 – Output Compare Register A Low byte
0x29 (0x49)
OCR1BH
Timer/Counter1 – Output Compare Register B High byte
0x28 (0x48)
OCR1BL
Timer/Counter1 – Output Compare Register B Low byte
0x27 (0x47)
ICR1H
Timer/Counter1 – Input Capture Register High byte
0x26 (0x46)
ICR1L
Timer/Counter1 – Input Capture Register Low byte
0x25 (0x45)
TCCR2
FOC2
WGM20
COM21
COM20
WGM21
CS22
CS21
CS20
0x24 (0x44)
TCNT2
Timer/Counter2 (8 Bits)
0x23 (0x43)
OCR2
Timer/Counter2 Output Compare Register
0x22 (0x42)
ASSR
–
AS2
TCN2UB
OCR2UB
TCR2UB
0x21 (0x41)
WDTCR
–
WDCE
WDE
WDP2
WDP1
WDP0
UBRRH
URSEL
–
UBRR[11:8]
UCSRC
URSEL
UMSEL
UPM1
UPM0
USBS
UCSZ1
UCSZ0
UCPOL
0x1F (0x3F)
EEARH
–
–EEAR8
0x1E (0x3E)
EEARL
EEAR7
EEAR6
EEAR5
EEAR4
EEAR3
EEAR2
EEAR1
EEAR0
0x1D (0x3D)
EEDR
EEPROM Data Register
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
0x17 (0x37)
DDRB
DDB7
DDB6
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0
0x16 (0x36)
PINB
PINB7
PINB6
PINB5
PINB4
PINB3
PINB2
PINB1
PINB0
0x15 (0x35)
PORTC
–
PORTC6
PORTC5
PORTC4
PORTC3
PORTC2
PORTC1
PORTC0
0x14 (0x34)
DDRC
–
DDC6
DDC5
DDC4
DDC3
DDC2
DDC1
DDC0
0x13 (0x33)
PINC
–
PINC6
PINC5
PINC4
PINC3
PINC2
PINC1
PINC0
0x12 (0x32)
PORTD
PORTD7
PORTD6
PORTD5
PORTD4
PORTD3
PORTD2
PORTD1
PORTD0
0x11 (0x31)
DDRD
DDD7
DDD6
DDD5
DDD4
DDD3
DDD2
DDD1
DDD0
0x10 (0x30)
PIND
PIND7
PIND6
PIND5
PIND4
PIND3
PIND2
PIND1
PIND0
0x0F (0x2F)
SPDR
SPI Data Register
0x0E (0x2E)
SPSR
SPIF
WCOL
–
–SPI2X
0x0D (0x2D)
SPCR
SPIE
SPE
DORD
MSTR
CPOL
CPHA
SPR1
SPR0
0x0C (0x2C)
UDR
USART I/O Data Register
0x0B (0x2B)
UCSRA
RXC
TXC
UDRE
FE
DOR
PE
U2X
MPCM
0x0A (0x2A)
UCSRB
RXCIE
TXCIE
UDRIE
RXEN
TXEN
UCSZ2
RXB8
TXB8
0x09 (0x29)
UBRRL
USART Baud Rate Register Low byte
0x08 (0x28)
ACSR
ACD
ACBG
ACO
ACI
ACIE
ACIC
ACIS1
ACIS0
0x07 (0x27)
ADMUX
REFS1
REFS0
ADLAR
–
MUX3
MUX2
MUX1
MUX0
0x06 (0x26)
ADCSRA
ADEN
ADSC
ADFR
ADIF
ADIE
ADPS2
ADPS1
ADPS0
0x05 (0x25)
ADCH
ADC Data Register High byte
0x04 (0x24)
ADCL
ADC Data Register Low byte
0x03 (0x23)
TWDR
Two-wire Serial Interface Data Register
0x02 (0x22)
TWAR
TWA6
TWA5
TWA4
TWA3
TWA2
TWA1
TWA0
TWGCE