AT90S/LS2333 and AT90S/LS4433
15
Figure 23. On-Chip Data SRAM Access Cycles
I/O Memory
The I/O space definition of the AT90S2333/4433 is shown in the following table:
Table 2. AT90S2333/4433 I/O Space
I/O Address (SRAM Address)
Name
Function
$3F ($5F)
SREG
Status REGister
$3D ($5D)
SP
Stack Pointer
$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 ($54)
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)
OCR1H
Timer/Counter1 Output Compare Register High Byte
$2A ($4A)
OCR1L
Timer/Counter1 Output Compare Register Low Byte
$27 ($47)
ICR1H
Timer/Counter1 Input Capture Register High Byte
$26 ($46)
ICR1L
Timer/Counter 1 Input Capture Register Low Byte
$21 ($41)
WDTCR
Watchdog Timer Control Register
$1E ($3E)
EEAR
EEPROM Address Register
$1D ($3D)
EEDR
EEPROM Data Register
$1C ($3C)
EECR
EEPROM Control Register
$18 ($38)
PORTB
Data Register, Port B
$17 ($37)
DDRB
Data Direction Register, Port B
$16 ($36)
PINB
Input Pins, Port B
System Clock Ø
WR
RD
Data
Data
Address
Address
T1
T2
T3
T4
Prev. Address
Read
Wr
ite