5

2545JS–AVR–12/06

ATmega48/88/168

2.

Overview

The ATmega48/88/168 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced

RISC architecture. By executing powerful instructions in a single clock cycle, the

ATmega48/88/168 achieves throughputs approaching 1 MIPS per MHz allowing the system

designer to optimize power consumption versus processing speed.

2.1

Block Diagram

Figure 2-1.

Block Diagram

The AVR core combines a rich instruction set with 32 general 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

PORT C (7)

PORT B (8)

PORT D (8)

USART 0

8bit T/C 2

16bit T/C 1

8bit T/C 0

A/D Conv.

Internal

Bandgap

Analog

Comp.

SPI

TWI

SRAM

Flash

EEPROM

Watchdog

Oscillator

Watchdog

Timer

Oscillator

Circuits /

Clock

Generation

Power

Supervision

POR / BOD &

RESET

PROGRAM

LOGIC

debugWIRE

2

GND

AREF

AVCC

ADC[6..7]

PC[0..6]

PB[0..7]

PD[0..7]

6

RESET

XTAL[1..2]

CPU