AT90S/LS4434 and AT90S/LS8535
16
I/O Memory
The I/O space definition of the AT90S4434/8535 is shown in Table 2.
Table 2.
AT90S4434/8535 I/O Space
I/O Address (SRAM Address)
Name
Function
$3F ($5F)
SREG
Status REGister
$3E ($5E)
SPH
Stack Pointer High
$3D ($5D)
SPL
Stack Pointer Low
$3B ($5B)
GIMSK
General Interrupt MaSK register
$3A ($5A)
GIFR
General Interrupt Flag Register
$39 ($59)
TIMSK
Timer/Counter Interrupt MaSK register
$38 ($58)
TIFR
Timer/Counter Interrupt Flag register
$35 ($55)
MCUCR
MCU general Control Register
$34 ($45)
MCUSR
MCU general Status Register
$33 ($53)
TCCR0
Timer/Counter0 Control Register
$32 ($52)
TCNT0
Timer/Counter0 (8-bit)
$2F ($4F)
TCCR1A
Timer/Counter1 Control Register A
$2E ($4E)
TCCR1B
Timer/Counter1 Control Register B
$2D ($4D)
TCNT1H
Timer/Counter1 High Byte
$2C ($4C)
TCNT1L
Timer/Counter1 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
T/C 1 Input Capture Register High Byte
$26 ($46)
ICR1L
T/C 1 Input Capture Register Low Byte
$25 ($45)
TCCR2
Timer/Counter2 Control Register
$24 ($44)
TCNT2
Timer/Counter2 (8-bit)
$23 ($43)
OCR2
Timer/Counter2 Output Compare Register
$22 ($42)
ASSR
Asynchronous Mode Status Register
$21 ($41)
WDTCR
Watchdog Timer Control Register
$1F ($3E)
EEARH
EEPROM Address Register High Byte
$1E ($3E)
EEARL
EEPROM Address Register Low Byte
$1D ($3D)
EEDR
EEPROM Data Register
$1C ($3C)
EECR
EEPROM Control Register
$1B ($3B)
PORTA
Data Register, Port A
$1A ($3A)
DDRA
Data Direction Register, Port A
$19 ($39)
PINA
Input Pins, Port A
$18 ($38)
PORTB
Data Register, Port B