5

8271BS–AVR–04/10

ATmega48A/48PA/88A/88PA/168A/168PA/328/328P

2.

Overview

The ATmega48A/48PA/88A/88PA/168A/168PA/328/328P is a low-power CMOS 8-bit microcon-

troller based on the AVR enhanced RISC architecture. By executing powerful instructions in a

single clock cycle, the ATmega48A/48PA/88A/88PA/168A/168PA/328/328P achieves through-

puts 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

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