AT90LS4434-4AI ATMEL Corporation, AT90LS4434-4AI Datasheet - Page 2

• Manufacturer Part Number: AT90LS4434-4AI
• Description: 8-Bit Microcontroller with 4K/8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Block Diagram
The AVR core combines a rich instruction set with 32 gen-
eral purpose working registers. All the 32 registers are
directly connected to the Arithmetic Logic Unit (ALU),
allowing two independent registers to be accessed in one
single instruction executed in one clock cycle. The resulting
architecture is more code efficient while achieving through-
puts up to ten times faster than conventional CISC micro-
controllers.
The AT90S4434/8535 provides the following features:
4K/8K bytes of In-System Programmable Flash, 256/512
bytes EEPROM, 256/512 bytes SRAM, 32 general purpose
I/O lines, 32 general purpose working registers, RTC, three
flexible timer/counters with compare modes, internal and
2
AT90S/LS4434 and AT90S/LS8535
AGND
AVCC
AREF
VCC
GND
PROGRAMMING
INSTRUCTION
INSTRUCTION
PROGRAM
PROGRAM
REGISTER
COUNTER
CONTROL
DECODER
FLASH
LOGIC
LINES
DATA REGISTER
DATA REGISTER
ANALOG MUX
PORTB
PORTA
PORTA DRIVERS
PORTB DRIVERS
PA0 - PA7
PB0 - PB7
REGISTERS
REGISTER
GENERAL
PURPOSE
POINTER
STATUS
STACK
SRAM
ALU
SPI
X
Y
Z
REG. PORTA
REG. PORTB
DATA DIR.
DATA DIR.
ADC
8-BIT DATA BUS
external interrupts, a programmable serial UART, 8-chan-
nel, 10-bit ADC, programmable Watchdog Timer with inter-
nal oscillator, an SPI serial port and three software
selectable power saving modes. The Idle mode stops the
CPU while allowing the SRAM, timer/counters, SPI port
and interrupt system to continue functioning. The Power
Down mode saves the register contents but freezes the
oscillator, disabling all other chip functions until the next
interrupt or hardware reset. In Power Save mode, the timer
oscillator continues to run, allowing the user to maintain a
timer base while the rest of the device is sleeping.
The device is manufactured using Atmel’s high density
non-volatile memory technology. The on-chip ISP Flash
DATA REGISTER
DATA REGISTER
MCU CONTROL
OSCILLATOR
WATCHDOG
INTERRUPT
COUNTERS
REGISTER
INTERNAL
EEPROM
PORTC
TIMER/
PORTD
TIMER
UART
UNIT
PORTC DRIVERS
PORTD DRIVERS
PC0 - PC7
PD0 - PD7
REG. PORTC
REG. PORTD
DATA DIR.
DATA DIR.
OSCILLATOR
OSCILLATOR
TIMING AND
CONTROL
XTAL1
XTAL2
RESET