Addr

Name

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

($FF)

Reserved

–

–

–

–

–

–

–

–

..

Reserved

–

–

–

–

–

–

–

–

($9E)

Reserved

–

–

–

–

–

–

–

–

($9D)

UCSR1C

–

UMSEL1

UPM11

UPM10

USBS1

UCSZ11

UCSZ10

UCPOL1

($9B)

UCSR1A

RXC1

TXC1

UDRE1

FE1

DOR1

UPE1

U2X1

MPCM1

($9A)

UCSR1B

RXCIE1

TXCIE1

UDRIE1

RXEN1

TXEN1

UCSZ12

RXB81

TXB81

($99)

UBRR1L

($98)

($97)

Reserved

–

–

–

–

–

–

–

–

($96)

Reserved

–

–

–

–

–

–

–

–

($95)

UCSR0C

–

UMSEL0

UPM01

UPM00

USBS0

UCSZ01

UCSZ00

UCPOL0

($94)

Reserved

–

–

–

–

–

–

–

–

($93)

Reserved

–

–

–

–

–

–

–

–

($92)

Reserved

–

–

–

–

–

–

–

–

($91)

Reserved

–

–

–

–

–

–

–

–

($90)

($8F)

Reserved

–

–

–

–

–

–

–

–

($8E)

Reserved

–

–

–

–

–

–

–

–

($8D)

Reserved

–

–

–

–

–

–

–

–

($8C)

TCCR3C

FOC3A

FOC3B

FOC3C

–

–

–

–

–

($8B)

TCCR3A

COM3A1

COM3A0

COM3B1

COM3B0

COM3C1

COM3C0

WGM31

WGM30

($8A)

TCCR3B

ICNC3

ICES3

–

WGM33

WGM32

CS32

CS31

CS30

($89)

TCNT3H

Timer/Counter3 – Counter Register High Byte

($88)

TCNT3L

Timer/Counter3 – Counter Register Low Byte

($87)

OCR3AH

Timer/Counter3 – Output Compare Register A High Byte

($86)

OCR3AL

Timer/Counter3 – Output Compare Register A Low Byte

($85)

OCR3BH

Timer/Counter3 – Output Compare Register B High Byte

($84)

OCR3BL

Timer/Counter3 – Output Compare Register B Low Byte

($83)

OCR3CH

Timer/Counter3 – Output Compare Register C High Byte

($82)

OCR3CL

Timer/Counter3 – Output Compare Register C Low Byte

($81)

ICR3H

Timer/Counter3 – Input Capture Register High Byte

($80)

ICR3L

Timer/Counter3 – Input Capture Register Low Byte

($7F)

Reserved

–

–

–

–

–

–

–

–

($7E)

Reserved

–

–

–

–

–

–

–

–

($7D)

ETIMSK

–

–

TICIE3

OCIE3A

OCIE3B

TOIE3

OCIE3C

OCIE1C

($7C)

ETIFR

–

–

ICF3

OCF3A

OCF3B

TOV3

OCF3C

OCF1C

($7B)

Reserved

–

–

–

–

–

–

–

–

($7A)

TCCR1C

FOC1A

FOC1B

FOC1C

–

–

–

–

–

($79)

OCR1CH

Timer/Counter1 – Output Compare Register C High Byte

($78)

OCR1CL

Timer/Counter1 – Output Compare Register C Low Byte

($77)

Reserved

–

–

–

–

–

–

–

–

($76)

Reserved

–

–

–

–

–

–

–

–

($75)

Reserved

–

–

–

–

–

–

–

–

($74)

TWCR

TWINT

TWEA

TWSTA

TWSTO

TWWC

TWEN

–

TWIE

($73)

TWDR

Two-wire Serial Interface Data Register

($72)

TWAR

TWA6

TWA5

TWA4

TWA3

TWA2

TWA1

TWA0

TWGCE

($71)

TWSR

TWS7

TWS6

TWS5

TWS4

TWS3

–

TWPS1

TWPS0

($70)

TWBR

Two-wire Serial Interface Bit Rate Register

($6F)

OSCCAL

Oscillator Calibration Register

($6E)

Reserved

–

–

–

–

–

–

–

–

($6D)

XMCRA

–

SRL2

SRL1

SRL0

SRW01

SRW00

SRW11

29

($6C)

XMCRB

XMBK

–

–

–

–

XMM2

XMM1

XMM0

($6B)

Reserved

–

–

–

–

–

–

–

–

($6A)

EICRA

ISC31

ISC30

ISC21

ISC20

ISC11

ISC10

ISC01

ISC00

($69)

Reserved

–

–

–

–

–

–

–

–

($68)

SPMCSR

SPMIE

RWWSB

–

RWWSRE

BLBSET

PGWRT

PGERS

SPMEN

($67)

Reserved

–

–

–

–

–

–

–

–

($66)

Reserved

–

–

–

–

–

–

–

–

($65)

PORTG

–

–

–

PORTG4

PORTG3

PORTG2

PORTG1

PORTG0

($64)

DDRG

–

–

–

DDG4

DDG3

DDG2

DDG1

DDG0

($63)

PING

–

–

–

PING4

PING3

PING2

PING1

PING0

($62)

PORTF

PORTF7

PORTF6

PORTF5

PORTF4

PORTF3

PORTF2

PORTF1

PORTF0

($61)

DDRF

DDF7

DDF6

DDF5

DDF4

DDF3

DDF2

DDF1

DDF0

($60)

Reserved

–

–

–

–

–

–

–

–

$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)

XDIV

XDIVEN

XDIV6

XDIV5

XDIV4

XDIV3

XDIV2

XDIV1

XDIV0

$3B($5B)

RAMPZ

–

–

–

–

–

–

–

RAMPZ0

$3A($5A)

EICRB

ISC71

ISC70

ISC61

ISC60

ISC51

ISC50

ISC41

ISC40

$39($59)

EIMSK

INT7

INT6

INT5

INT4

INT3

INT2

INT1

INT0

$38($58)

EIFR

INTF7

INTF6

INTF5

INTF4

INTF3

INTF

INTF1

INTF0

$37($57)

TIMSK

OCIE2

TOIE2

TICIE1

OCIE1A

OCIE1B

TOIE1

OCIE0

TOIE0

$36($56)

TIFR

OCF2

TOV2

ICF1

OCF1A

OCF1B

TOV1

OCF0

TOV0

$35($55)

MCUCR

SRE

SRW10

SE

SM1

SM0

SM2

IVSEL

IVCE

$34($54)

MCUCSR

JTD

–

–

JTRF

WDRF

BORF

EXTRF

PORF

$33($53)

TCCR0

FOC0

WGM00

COM01

COM00

WGM01

CS02

CS01

CS00

$32($52)

TCNT0

Timer/Counter0 (8 Bit)

$31($51)

OCR0

Timer/Counter0 Output Compare Register

$30($50)

ASSR

–

–

–

–

AS0

TCN0UB

OCR0UB

TCR0UB

$2F($4F)

TCCR1A

COM1A1

COM1A0

COM1B1

COM1B0

COM1C1

COM1C0

WGM11

WGM10

$2E($4E)

TCCR1B

ICNC1

ICES1

–

WGM13

WGM12

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)

ICR1H

Timer/Counter1 – Input Capture Register High Byte

$26($46)

ICR1L

Timer/Counter1 – Input Capture Register Low Byte

$25($45)

TCCR2

FOC2

WGM20

COM21

COM20

WGM21

CS22

CS21

CS20

$24($44)

TCNT2

Timer/Counter2 (8 Bit)

$23($43)

OCR2

Timer/Counter2 Output Compare Register

$22($42)

OCDR

IDRD/OCDR7

OCDR6

OCDR5

OCDR4

OCDR3

OCDR2

OCDR1

OCDR0

$21($41)

WDTCR

–

–

–

WDCE

WDE

WDP2

WDP1

WDP0

$20($40)

SFIOR

TSM

–

–

–

ACME

PUD

PSR0

PSR321

$1F($3F)

EEARH

–

–

–

–

EEPROM Address Register High Byte

$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

USART0 I/O Data Register

$0B($2B)

UCSR0A

RXC0

TXC0

UDRE0

FE0

DOR0

UPE0

U2X0

MPCM0

$0A($2A)

UCSR0B

RXCIE0

TXCIE0

UDRIE0

RXEN0

TXEN0

UCSZ02

RXB80

TXB80

$09($29)

UBRR0L

USART0

Baud

Rate

Register

Low

194

$08($28)

ACSR

ACD

ACBG

ACO

ACI

ACIE

ACIC

ACIS1

ACIS0

$07($27)

ADMUX

REFS1

REFS0

ADLAR

MUX4

MUX3

MUX2

MUX1

MUX0

$06($26)

ADCSRA

ADEN

ADSC

ADFR

ADIF

ADIE

ADPS2

ADPS1

ADPS0

$05($25)

ADCH

ADC Data Register High Byte

$04($24)

ADCL

ADC Data Register Low byte

$03($23)

PORTE

PORTE7

PORTE6

PORTE5

PORTE4

PORTE3

PORTE2

PORTE1

PORTE0

$02($22)

DDRE

DDE7

DDE6

DDE5

DDE4

DDE3

DDE2

DDE1

DDE0

$01($21)

PINE

PINE7

PINE6

PINE5

PINE4

PINE3

PINE2

PINE1

PINE0

$00($20)

PINF

PINF7

PINF6

PINF5

PINF4

PINF3

PINF2

PINF1

PINF0