ATMEGA48V-10AU 参数 Datasheet PDF下载

ATmega48/88/168

4. AVR CPU Core

4.1

Introduction

This section discusses the AVR core architecture in general. The main function of the CPU core

is to ensure correct program execution. The CPU must therefore be able to access memories,

perform calculations, control peripherals, and handle interrupts.

4.2

Architectural Overview

Figure 4-1.

Block Diagram of the AVR Architecture

Data Bus 8-bit

Flash

Program

Memory

Program

Counter

Status

and Control

Instruction

Register

32 x 8

General

Purpose

Registrers

Interrupt

Unit

SPI

Unit

Watchdog

Timer

Indirect Addressing

Instruction

Decoder

Direct Addressing

ALU

Control Lines

Analog

Comparator

I/O Module1

Data

SRAM

I/O Module 2

I/O Module n

EEPROM

I/O Lines

In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with

separate memories and buses for program and data. Instructions in the program memory are

executed with a single level pipelining. While one instruction is being executed, the next instruc-

tion is pre-fetched from the program memory. This concept enables instructions to be executed

in every clock cycle. The program memory is In-System Reprogrammable Flash memory.

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2545E–AVR–02/05