4

8183BS–AVR–03/10

ATtiny24A/44A

2. Overview

ATtiny24A/44A are low-power CMOS 8-bit microcontrollers based on the AVR enhanced RISC

architecture. By executing powerful instructions in a single clock cycle, the ATtiny24A/44A

achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize

power consumption versus processing speed.

Figure 2-1.

Block Diagram

The AVR core combines a rich instruction set with 32 general purpose working registers. All 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 throughputs up to ten times faster than con-

ventional CISC microcontrollers.

WATCHDOG

TIMER

MCU CONTROL

REGISTER

TIMER/

COUNTER0

DATA DIR.

REG.PORT A

DATA REGISTER

PORT A

PROGRAMMING

LOGIC

TIMING AND

CONTROL

MCU STATUS

REGISTER

PORT A DRIVERS

PA7-PA0

VCC

GND

8-BIT DATABUS

ADC

ISP INTERFACE

INTERRUPT

UNIT

EEPROM

INTERNAL

OSCILLATOR

OSCILLATORS

CALIBRATED

OSCILLATOR

INTERNAL

DATA DIR.

REG.PORT B

DATA REGISTER

PORT B

PORT B DRIVERS

PB3-PB0

PROGRAM

COUNTER

STACK

POINTER

PROGRAM

FLASH

SRAM

GENERAL

PURPOSE

REGISTERS

INSTRUCTION

REGISTER

INSTRUCTION

DECODER

STATUS

REGISTER

Z

Y

X

ALU

CONTROL

LINES

TIMER/

COUNTER1