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

page 20

$3E

($5E)

SPH

SP15

SP14

SP13

 

SP12

SP11

SP10

 

SP9

SP8

page 21

$3D

($5D)

SPL

SP7

SP6

SP5

 

SP4

SP3

SP2

 

SP1

SP0

page 21

$3C

($5C)

Reserved

 

 

 

 

 

 

 

 

 

 

 

$3B

($5B)

GIMSK

INT1

INT0

-

 

-

-

-

 

-

-

page 26

$3A

($5A)

GIFR

INTF1

INTF0

 

 

 

 

 

 

 

 

page 26

$39

($59)

TIMSK

TOIE1

OCIE1A

OCIE1B

 

-

TICIE1

-

 

TOIE0

-

page 27

$38

($58)

TIFR

TOV1

OCF1A

OCF1B

 

-

ICF1

-

 

TOV0

-

page 28

$37

($57)

Reserved

 

 

 

 

 

 

 

 

 

 

 

$36

($56)

Reserved

 

 

 

 

 

 

 

 

 

 

 

$35

($55)

MCUCR

SRE

SRW

SE

 

SM

ISC11

ISC10

 

ISC01

ISC00

page 29

$34

($54)

Reserved

 

 

 

 

 

 

 

 

 

 

 

$33

($53)

TCCR0

-

-

-

 

-

-

CS02

 

CS01

CS00

page 33

$32

($52)

TCNT0

 

 

 

 

Timer/Counter0 (8 Bits)

 

 

 

 

page 34

 

...

Reserved

 

 

 

 

 

 

 

 

 

 

 

$2F

($4F)

TCCR1A

COM1A1

COM1A0

COM1B1

 

COM1B0

-

-

 

PWM11

PWM10

page 35

$2E

($4E)

TCCR1B

ICNC1

ICES1

-

 

-

CTC1

CS12

 

CS11

CS10

page 36

$2D

($4D)

TCNT1H

 

 

Timer/Counter1 – Counter Register High Byte

 

 

page 38

$2C

($4C)

TCNT1L

 

 

Timer/Counter1 – Counter Register Low Byte

 

 

page 38

$2B

($4B)

OCR1AH

 

 

Timer/Counter1 – Output Compare Register A High Byte

 

 

page 38

$2A

($4A)

OCR1AL

 

 

Timer/Counter1 – Output Compare Register A Low Byte

 

 

page 38

$29

($49)

OCR1BH

 

 

Timer/Counter1 – Output Compare Register B High Byte

 

 

page 39

$28

($48)

OCR1BL

 

 

Timer/Counter1 – Output Compare Register B Low Byte

 

 

page 39

 

...

Reserved

 

 

 

 

 

 

 

 

 

 

 

$25

($45)

ICR1H

 

 

Timer/Counter1 – Input Capture Register High Byte

 

 

page 39

$24

($44)

ICR1L

 

 

Timer/Counter1 – Input Capture Register Low Byte

 

 

page 39

 

...

Reserved

 

 

 

 

 

 

 

 

 

 

 

$21

($41)

WDTCR

-

-

-

 

WDTOE

WDE

WDP2

 

WDP1

WDP0

page 42

$20

($40)

Reserved

 

 

 

 

 

 

 

 

 

 

 

$1F

($3F)

EEARH

-

-

-

 

-

-

-

 

-

EEAR8

page 44

$1E

($3E)

EEARL

 

 

 

EEPROM Address Register Low Byte

 

 

page 44

$1D

($3D)

EEDR

 

 

 

 

EEPROM Data Register

 

 

 

 

page 44

$1C

($3C)

EECR

-

-

-

 

-

-

EEMWE

 

EEWE

EERE

page 44

$1B

($3B)

PORTA

PORTA7

PORTA6

PORTA5

 

PORTA4

PORTA3

PORTA2

 

PORTA1

PORTA0

page 63

$1A

($3A)

DDRA

DDA7

DDA6

DDA5

 

DDA4

DDA3

DDA2

 

DDA1

DDA0

page 63

$19

($39)

PINA

PINA7

PINA6

PINA5

 

PINA4

PINA3

PINA2

 

PINA1

PINA0

page 63

$18

($38)

PORTB

PORTB7

PORTB6

PORTB5

 

PORTB4

PORTB3

PORTB2

 

PORTB1

PORTB0

page 65

$17

($37)

DDRB

DDB7

DDB6

DDB5

 

DDB4

DDB3

DDB2

 

DDB1

DDB0

page 65

$16

($36)

PINB

PINB7

PINB6

PINB5

 

PINB4

PINB3

PINB2

 

PINB1

PINB0

page 65

$15

($35)

PORTC

PORTC7

PORTC6

PORTC5

 

PORTC4

PORTC3

PORTC2

 

PORTC1

PORTC0

page 70

$14

($34)

DDRC

DDC7

DDC6

DDC5

 

DDC4

DDC3

DDC2

 

DDC1

DDC0

page 71

$13

($33)

PINC

PINC7

PINC6

PINC5

 

PINC4

PINC3

PINC2

 

PINC1

PINC0

page 71

$12

($32)

PORTD

PORTD7

PORTD6

PORTD5

 

PORTD4

PORTD3

PORTD2

 

PORTD1

PORTD0

page 73

$11

($31)

DDRD

DDD7

DDD6

DDD5

 

DDD4

DDD3

DDD2

 

DDD1

DDD0

page 73

$10

($30)

PIND

PIND7

PIND6

PIND5

 

PIND4

PIND3

PIND2

 

PIND1

PIND0

page 73

$0F

($2F)

SPDR

 

 

 

 

SPI Data Register

 

 

 

 

page 51

$0E

($2E)

SPSR

SPIF

WCOL

-

 

-

-

-

 

-

-

page 50

$0D

($2D)

SPCR

SPIE

SPE

DORD

 

MSTR

CPOL

CPHA

 

SPR1

SPR0

page 49

$0C

($2C)

UDR

 

 

 

 

UART I/O Data Register

 

 

 

 

page 55

$0B

($2B)

USR

RXC

TXC

UDRE

 

FE

OR

-

 

-

-

page 55

$0A

($2A)

UCR

RXCIE

TXCIE

UDRIE

 

RXEN

TXEN

CHR9

 

RXB8

TXB8

page 56

$09

($29)

UBRR

 

 

 

 

UART Baud Rate Register

 

 

 

 

page 58

$08

($28)

ACSR

ACD

-

ACO

 

ACI

ACIE

ACIC

 

ACIS1

ACIS0

page 59

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

$00

($20)

Reserved

 

 

 

 

 

 

 

 

 

 

 

Notes: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory addresses should never be written.

2.Some of the status flags are cleared by writing a logical “1” to them. Note that the CBI and SBI instructions will operate on all bits in the I/O register, writing a one back into any flag read as set, thus clearing the flag. The CBI and SBI instructions work with registers $00 to $1F only.

6AT90S8515

0841GS–09/01