Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
$3F ($5F)
$3E ($5E)
$3D ($5D)
$3C ($5C)
$3B ($5B)
$3A ($5A)
$39 ($59)
$38 ($58)
$37 ($57)
$36 ($56)
$35 ($55)
$34 ($54)
$33 ($53)
$32 ($52)
SREG
SPH
I
–
T
–
H
–
S
–
V
–
N
Z
C
7
SP10
SP2
SP9
SP1
SP8
SP0
10
SPL
SP7
SP6
SP5
SP4
SP3
10
Timer/Counter0 Output Compare Register
OCR0
83
GICR
INT1
INTF1
OCIE2
OCF2
SPMIE
TWINT
SM2
INT0
INTF0
TOIE2
TOV2
RWWSB
TWEA
SE
INT2
INTF2
TICIE1
ICF1
–
–
–
–
IVSEL
–
IVCE
–
46, 67
GIFR
–
–
–
68
TIMSK
TIFR
OCIE1A
OCF1A
RWWSRE
TWSTO
SM0
OCIE1B
OCF1B
BLBSET
TWWC
ISC11
WDRF
WGM01
TOIE1
TOV1
PGWRT
TWEN
ISC10
BORF
CS02
OCIE0
OCF0
PGERS
–
TOIE0
TOV0
SPMEN
TWIE
ISC00
PORF
CS00
83, 114, 132
84, 115, 132
SPMCR
TWCR
MCUCR
MCUCSR
TCCR0
TCNT0
OSCCAL
OCDR
SFIOR
TCCR1A
TCCR1B
TCNT1H
TCNT1L
OCR1AH
OCR1AL
OCR1BH
OCR1BL
ICR1H
ICR1L
250
TWSTA
SM1
178
ISC01
EXTRF
CS01
30, 66
JTD
ISC2
–
JTRF
39, 67, 229
FOC0
WGM00
COM01
COM00
81
83
Timer/Counter0 (8 Bits)
Oscillator Calibration Register
On-Chip Debug Register
28
$31(1) ($51)(1)
225
55,86,133,199,219
109
112
113
113
113
113
113
113
114
114
127
129
129
130
41
$30 ($50)
$2F ($4F)
$2E ($4E)
$2D ($4D)
$2C ($4C)
$2B ($4B)
$2A ($4A)
$29 ($49)
$28 ($48)
$27 ($47)
$26 ($46)
$25 ($45)
$24 ($44)
$23 ($43)
$22 ($42)
$21 ($41)
ADTS2
COM1A1
ICNC1
ADTS1
COM1A0
ICES1
ADTS0
COM1B1
–
–
ACME
FOC1A
WGM12
PUD
FOC1B
CS12
PSR2
WGM11
CS11
PSR10
WGM10
CS10
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
Timer/Counter1 – Input Capture Register High Byte
Timer/Counter1 – Input Capture Register Low Byte
TCCR2
TCNT2
OCR2
FOC2
Timer/Counter2 (8 Bits)
Timer/Counter2 Output Compare Register
WGM20
COM21
COM20
WGM21
CS22
CS21
CS20
ASSR
–
–
–
–
–
WDTOE
–
AS2
TCN2UB
WDP2
OCR2UB
WDP1
TCR2UB
WDP0
WDTCR
UBRRH
UCSRC
EEARH
EEARL
EEDR
–
–
WDE
URSEL
URSEL
–
–
UMSEL
–
–
UPM1
–
UBRR[11:8]
165
164
17
$20(2) ($40)(2)
UPM0
–
USBS
–
UCSZ1
–
UCSZ0
–
UCPOL
EEAR8
$1F ($3F)
$1E ($3E)
$1D ($3D)
$1C ($3C)
$1B ($3B)
$1A ($3A)
$19 ($39)
$18 ($38)
$17 ($37)
$16 ($36)
$15 ($35)
$14 ($34)
$13 ($33)
$12 ($32)
$11 ($31)
$10 ($30)
$0F ($2F)
$0E ($2E)
$0D ($2D)
$0C ($2C)
$0B ($2B)
$0A ($2A)
$09 ($29)
$08 ($28)
$07 ($27)
$06 ($26)
$05 ($25)
$04 ($24)
$03 ($23)
$02 ($22)
EEPROM Address Register Low Byte
EEPROM Data Register
17
17
EECR
–
–
–
–
EERIE
PORTA3
DDA3
EEMWE
PORTA2
DDA2
EEWE
PORTA1
DDA1
EERE
PORTA0
DDA0
17
PORTA
DDRA
PORTA7
DDA7
PORTA6
DDA6
PORTA5
DDA5
PORTA4
DDA4
64
64
PINA
PINA7
PINA6
PORTB6
DDB6
PINA5
PORTB5
DDB5
PINA4
PORTB4
DDB4
PINA3
PINA2
PINA1
PINA0
64
PORTB
DDRB
PORTB7
DDB7
PORTB3
DDB3
PORTB2
DDB2
PORTB1
DDB1
PORTB0
DDB0
64
64
PINB
PINB7
PINB6
PORTC6
DDC6
PINB5
PORTC5
DDC5
PINB4
PORTC4
DDC4
PINB3
PINB2
PINB1
PINB0
64
PORTC
DDRC
PINC
PORTC7
DDC7
PORTC3
DDC3
PORTC2
DDC2
PORTC1
DDC1
PORTC0
DDC0
65
65
PINC7
PINC6
PORTD6
DDD6
PINC5
PORTD5
DDD5
PINC4
PORTD4
DDD4
PINC3
PORTD3
DDD3
PINC2
PINC1
PORTD1
DDD1
PINC0
PORTD0
DDD0
65
PORTD
DDRD
PIND
PORTD7
DDD7
PORTD2
DDD2
65
65
PIND7
PIND6
PIND5
PIND4
PIND3
PIND2
PIND1
PIND0
65
SPDR
SPI Data Register
SPIF
140
140
138
161
162
163
165
200
215
217
218
218
180
180
SPSR
WCOL
SPE
–
–
–
–
–
SPI2X
SPR0
SPCR
SPIE
DORD
MSTR
CPOL
CPHA
SPR1
UDR
USART I/O Data Register
UCSRA
UCSRB
UBRRL
ACSR
RXC
TXC
UDRE
UDRIE
FE
DOR
PE
U2X
MPCM
TXB8
RXCIE
TXCIE
RXEN
TXEN
UCSZ2
RXB8
USART Baud Rate Register Low Byte
ACD
REFS1
ADEN
ACBG
REFS0
ADSC
ACO
ACI
MUX4
ADIF
ACIE
MUX3
ADIE
ACIC
MUX2
ADPS2
ACIS1
MUX1
ADPS1
ACIS0
MUX0
ADPS0
ADMUX
ADCSRA
ADCH
ADLAR
ADATE
ADC Data Register High Byte
ADC Data Register Low Byte
ADCL
TWDR
TWAR
Two-wire Serial Interface Data Register
TWA6 TWA5 TWA4
TWA3
TWA2
TWA1
TWA0
TWGCE
6
ATmega16(L)
2466NS–AVR–10/06
ATMEL [ ATMEL ]
