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7
ATmega8(L)
2486LS–AVR–10/03
Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
0x3F (0x5F)
0x3E (0x5E)
0x3D (0x5D)
0x3C (0x5C)
0x3B (0x5B)
0x3A (0x5A)
0x39 (0x59)
0x38 (0x58)
0x37 (0x57)
0x36 (0x56)
0x35 (0x55)
0x34 (0x54)
0x33 (0x53)
0x32 (0x52)
0x31 (0x51)
0x30 (0x50)
0x2F (0x4F)
0x2E (0x4E)
0x2D (0x4D)
0x2C (0x4C)
0x2B (0x4B)
0x2A (0x4A)
0x29 (0x49)
0x28 (0x48)
0x27 (0x47)
0x26 (0x46)
0x25 (0x45)
0x24 (0x44)
0x23 (0x43)
0x22 (0x42)
0x21 (0x41)
SREG
SPH
SPL
Reserved
GICR
GIFR
TIMSK
TIFR
SPMCR
TWCR
MCUCR
MCUCSR
TCCR0
TCNT0
OSCCAL
SFIOR
TCCR1A
TCCR1B
TCNT1H
TCNT1L
OCR1AH
OCR1AL
OCR1BH
OCR1BL
ICR1H
ICR1L
TCCR2
TCNT2
OCR2
ASSR
WDTCR
UBRRH
UCSRC
EEARH
EEARL
EEDR
EECR
Reserved
Reserved
Reserved
PORTB
DDRB
PINB
PORTC
DDRC
PINC
PORTD
DDRD
PIND
SPDR
SPSR
SPCR
UDR
UCSRA
UCSRB
UBRRL
ACSR
ADMUX
ADCSRA
ADCH
ADCL
TWDR
TWAR
I
–
T
–
H
–
S
–
V
–
N
Z
C
9
SP10
SP2
SP9
SP1
SP8
SP0
11
11
SP7
SP6
SP5
SP4
SP3
INT1
INTF1
OCIE2
OCF2
SPMIE
TWINT
SE
–
–
INT0
INTF0
TOIE2
TOV2
RWWSB
TWEA
SM2
–
–
–
–
–
–
–
–
–
–
IVSEL
–
–
–
PGERS
–
ISC01
EXTRF
CS01
IVCE
–
TOIE0
TOV0
SPMEN
TWIE
ISC00
PORF
CS00
47, 65
66
70, 100, 120
71, 101, 120
209
167
31, 64
39
70
70
29
56, 73, 121, 189
95
98
99
99
99
99
99
99
100
100
115
117
117
117
41
154
152
18
18
18
18
TICIE1
ICF1
–
TWSTA
SM1
–
–
OCIE1A
OCF1A
RWWSRE
TWSTO
SM0
–
–
Timer/Counter0 (8 Bits)
Oscillator Calibration Register
–
COM1B0
WGM13
Timer/Counter1 – Counter Register High byte
Timer/Counter1 – Counter Register Low byte
Timer/Counter1 – Output Compare Register A High byte
Timer/Counter1 – Output Compare Register A Low byte
Timer/Counter1 – Output Compare Register B High byte
Timer/Counter1 – Output Compare Register B Low byte
OCIE1B
OCF1B
BLBSET
TWWC
ISC11
WDRF
–
TOIE1
TOV1
PGWRT
TWEN
ISC10
BORF
CS02
–
–
–
ACME
FOC1A
WGM12
PUD
FOC1B
CS12
PSR2
WGM11
CS11
PSR10
WGM10
CS10
COM1A1
ICNC1
COM1A0
ICES1
COM1B1
–
Timer/Counter1 – Input Capture Register High byte
Timer/Counter1 – Input Capture Register Low byte
COM21
COM20
Timer/Counter2 (8 Bits)
Timer/Counter2 Output Compare Register
FOC2
WGM20
WGM21
CS22
CS21
CS20
–
–
–
–
–
–
–
–
–
AS2
WDE
TCN2UB
WDP2
OCR2UB
WDP1
TCR2UB
WDP0
WDCE
–
UPM0
–
EEAR4
EEPROM Data Register
–
0x20
(1)
(0x40)
(1)
URSEL
URSEL
–
EEAR7
UBRR[11:8]
UMSEL
–
EEAR6
UPM1
–
EEAR5
USBS
–
EEAR3
UCSZ1
–
EEAR2
UCSZ0
–
EEAR1
UCPOL
EEAR8
EEAR0
0x1F (0x3F)
0x1E (0x3E)
0x1D (0x3D)
0x1C (0x3C)
0x1B (0x3B)
0x1A (0x3A)
0x19 (0x39)
0x18 (0x38)
0x17 (0x37)
0x16 (0x36)
0x15 (0x35)
0x14 (0x34)
0x13 (0x33)
0x12 (0x32)
0x11 (0x31)
0x10 (0x30)
0x0F (0x2F)
0x0E (0x2E)
0x0D (0x2D)
0x0C (0x2C)
0x0B (0x2B)
0x0A (0x2A)
0x09 (0x29)
0x08 (0x28)
0x07 (0x27)
0x06 (0x26)
0x05 (0x25)
0x04 (0x24)
0x03 (0x23)
0x02 (0x22)
–
–
–
EERIE
EEMWE
EEWE
EERE
PORTB7
DDB7
PINB7
–
–
–
PORTD7
DDD7
PIND7
PORTB6
DDB6
PINB6
PORTC6
DDC6
PINC6
PORTD6
DDD6
PIND6
PORTB5
DDB5
PINB5
PORTC5
DDC5
PINC5
PORTD5
DDD5
PIND5
PORTB4
DDB4
PINB4
PORTC4
DDC4
PINC4
PORTD4
DDD4
PIND4
PORTB3
DDB3
PINB3
PORTC3
DDC3
PINC3
PORTD3
DDD3
PIND3
PORTB2
DDB2
PINB2
PORTC2
DDC2
PINC2
PORTD2
DDD2
PIND2
PORTB1
DDB1
PINB1
PORTC1
DDC1
PINC1
PORTD1
DDD1
PIND1
PORTB0
DDB0
PINB0
PORTC0
DDC0
PINC0
PORTD0
DDD0
PIND0
63
63
63
63
63
63
63
63
63
128
128
126
149
150
151
154
190
201
203
204
204
169
170
SPI Data Register
–
MSTR
USART I/O Data Register
FE
RXEN
USART Baud Rate Register Low byte
ACI
–
ADIF
ADC Data Register High byte
ADC Data Register Low byte
Two-wire Serial Interface Data Register
TWA3
SPIF
SPIE
WCOL
SPE
–
–
–
–
SPI2X
SPR0
DORD
CPOL
CPHA
SPR1
RXC
RXCIE
TXC
TXCIE
UDRE
UDRIE
DOR
TXEN
PE
U2X
RXB8
MPCM
TXB8
UCSZ2
ACD
REFS1
ADEN
ACBG
REFS0
ADSC
ACO
ADLAR
ADFR
ACIE
MUX3
ADIE
ACIC
MUX2
ADPS2
ACIS1
MUX1
ADPS1
ACIS0
MUX0
ADPS0
TWA6
TWA5
TWA4
TWA2
TWA1
TWA0
TWGCE