Manual

3
AT90S/LS8535
1041H–11/01
Description The AT90S8535 is a low-power CMOS 8-bit microcontroller based on the AVR RISC
architecture. By executing powerful instructions in a single clock cycle, the AT90S8535
achieves throughputs approaching 1 MIPS per MHz allowing the system designer to
optimize power consumption versus processing speed.
Block Diagram Figure 1. The AT90S8535 Block Diagram
PROGRAM
COUNTER
INTERNAL
OSCILLATOR
WATCHDOG
TIMER
STACK
POINTER
PROGRAM
FLASH
MCU CONTROL
REGISTER
SRAM
GENERAL
PURPOSE
REGISTERS
INSTRUCTION
REGISTER
TIMER/
COUNTERS
INSTRUCTION
DECODER
DATA DIR.
REG. PORTB
DATA DIR.
REG. PORTA
DATA DIR.
REG. PORTD
DATA DIR.
REG. PORTC
DATA REGISTER
PORTB
DATA REGISTER
PORTA
ANALOG MUX ADC
DATA REGISTER
PORTD
DATA REGISTER
PORTC
PROGRAMMING
LOGIC
TIMING AND
CONTROL
OSCILLATOR
OSCILLATOR
INTERRUPT
UNIT
EEPROM
SPI
UART
STATUS
REGISTER
Z
Y
X
ALU
PORTB DRIVERS
PORTA DRIVERS
PORTD DRIVERS
PORTC DRIVERS
PB0 - PB7
PA0 - PA7
RESET
VCC
AVCC
AGND
AREF
GND
XTAL2
XTAL1
CONTROL
LINES
+
-
ANALOG
COMP
ARATOR
PD0 - PD7
PC0 - PC7
8-BIT DATA BUS