6
AT90S8515
0841GS–09/01
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.
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