142
ATmega161(L)
1228B–09/01
Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
$3F ($5F)
SREG
I
T
H
S
V
N
Z
C
$3E ($5E)
SPH
SP15
SP14
SP13
SP12
SP11
SP10
SP9
SP8
$3D ($5D)
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
$3C ($5C)
Reserved
$3B ($5B)
GIMSK
INT1
INT0
INT2
-
-
-
-
-
$3A ($5A)
GIFR
INTF1
INTF0
INTF2
$39 ($59)
TIMSK
TOIE1
OCIE1A
OCIE1B
TOIE2
TICIE1
OCIE2
TOIE0
OCIE0
$38 ($58)
TIFR
TOV1
OCF1A
OCF1B
TOV2
ICF1
OCFI2
TOV0
OCIF0
$37 ($57)
SPMCR
-
-
-
-
LBSET
PGWRT
PGERS
SPMEN
$36 ($56)
EMCUCR
SM0
SRL2
SRL1
SRL0
SRW01
SRW00
SRW11
ISC2
$35 ($55)
MCUCR
SRE
SRW10
SE
SM1
ISC11
ISC10
ISC01
ISC00
$34 ($54)
MCUSR
-
-
-
-
WDRF
BORF
EXTRF
PORF
$33 ($53)
TCCR0
FOC0
PWM0
COM01
COM00
CTC0
CS02
CS01
CS00
$32 ($52)
TCNT0
Timer/Counter0 Counter Register
$31 ($51)
OCR0
Timer/Counter0 Output Compare Register
$30 ($50)
SFIOR
-
-
-
-
-
-
PSR2
PSR10
$2F ($4F)
TCCR1A
COM1A1
COM1A0
COM1B1
COM1B0
FOC1A
FOC1B
PWM11
PWM10
$2E ($4E)
TCCR1B
ICNC1
ICES1
-
-
CTC1
CS12
CS11
CS10
$2D ($4D)
TCNT1H
Timer/Counter1 - Counter Register High Byte
$2C ($4C)
TCNT1L
Timer/Counter1 - Counter Register Low Byte
$2B ($4B)
OCR1AH
Timer/Counter1 - Output Compare Register A High Byte
$2A ($4A)
OCR1AL
Timer/Counter1 - Output Compare Register A Low Byte
$29 ($49)
OCR1BH
Timer/Counter1 - Output Compare Register B High Byte
$28 ($48)
OCR1BL
Timer/Counter1 - Output Compare Register B Low Byte
$27 ($47)
TCCR2
FOC2
PWM2
COM21
COM20
CTC2
CS22
CS21
CS20
$26 ($46)
ASSR
-
-
-
-
AS20
TCON2UB
OCR2UB
TCR2UB
$25 ($45)
ICR1H
Timer/Counter1 - Input Capture Register High Byte
$24 ($44)
ICR1L
Timer/Counter1 - Input Capture Register Low Byte
$23 ($43)
TCNT2
Timer/Counter2 Counter Register
$22 ($42)
OCR2
Timer/Counter2 Output Compare Register
$21 ($41)
WDTCR
-
-
-
WDTOE
WDE
WDP2
WDP1
WDP0
$20 ($40)
UBRRHI
UBRR1[11:8]
UBRR0[11:8]
$1F ($3F)
EEARH
-
-
-
-
-
-
-
EEAR8
$1E ($3E)
EEARL
EEPROM Address Register Low Byte
$1D ($3D)
EEDR
EEPROM Data Register
$1C ($3C)
EECR
-
-
-
-
EERIE
EEMWE
EEWE
EERE
$1B ($3B)
PORTA
PORTA7
PORTA6
PORTA5
PORTA4
PORTA3
PORTA2
PORTA1
PORTA0
$1A ($3A)
DDRA
DDA7
DDA6
DDA5
DDA4
DDA3
DDA2
DDA1
DDA0
$19 ($39)
PINA
PINA7
PINA6
PINA5
PINA4
PINA3
PINA2
PINA1
PINA0
$18 ($38)
PORTB
PORTB7
PORTB6
PORTB5
PORTB4
PORTB3
PORTB2
PORTB1
PORTB0
$17 ($37)
DDRB
DDB7
DDB6
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0
$16 ($36)
PINB
PINB7
PINB6
PINB5
PINB4
PINB3
PINB2
PINB1
PINB0
$15 ($35)
PORTC
PORTC7
PORTC6
PORTC5
PORTC4
PORTC3
PORTC2
PORTC1
PORTC0
$14 ($34)
DDRC
DDC7
DDC6
DDC5
DDC4
DDC3
DDC2
DDC1
DDC0
$13 ($33)
PINC
PINC7
PINC6
PINC5
PINC4
PINC3
PINC2
PINC1
PINC0
$12 ($32)
PORTD
PORTD7
PORTD6
PORTD5
PORTD4
PORTD3
PORTD2
PORTD1
PORTD0
$11 ($31)
DDRD
DDD7
DDD6
DDD5
DDD4
DDD3
DDD2
DDD1
DDD0
$10 ($30)
PIND
PIND7
PIND6
PIND5
PIND4
PIND3
PIND2
PIND1
PIND0
$0F ($2F)
SPDR
SPI Data Register
$0E ($2E)
SPSR
SPIF
WCOL
-
-
-
-
-
SPI2X
$0D ($2D)
SPCR
SPIE
SPE
DORD
MSTR
CPOL
CPHA
SPR1
SPR0
$0C ($2C)
UDR0
UART0 I/O Data Register
$0B ($2B)
UCSR0A
RXC0
TXC0
UDRE0
FE0
OR0
-
U2X0
MPCM0
$0A ($2A)
UCSR0B
RXCIE0
TXCIE0
UDRIE0
RXEN0
TXEN0
CHR90
RXB80
TXB80
$09 ($29)
UBRR0
UART0 Baud Rate Register
$08 ($28)
ACSR
ACD
AINBG
ACO
ACI
ACIE
ACIC
ACIS1
ACIS0
$07 ($27)
PORTE
-
-
-
-
-
PORTE2
PORTE1
PORTE0
$06 ($26)
DDRE
-
-
-
-
-
DDE2
DDE1
DDE0
$05 ($25)
PINE
-
-
-
-
-
PINE2
PINE1
PINE0
$04 ($24)
Reserved
$03 ($23)
UDR1
UART1 I/O Data Register
$02 ($22)
UCSR1A
RXC1
TXC1
UDRE1
FE1
OR1
-
U2X1
MPCM1
$01 ($21)
UCSR1B
RXCIE1
TXCIE1
UDRIE1
RXEN1
TXEN1
CHR91
RXB81
TXB81
$00 ($20)
UBRR1
UART1 Baud Rate Register