ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 8

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

7. AVR CPU Core
7.1
8
Overview
Atmel ATmega48PA/88PA/168PA [Preliminary]
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 mem-
ories, perform calculations, control peripherals, and handle interrupts.
Figure 7-1.
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
instruction 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.
Control Lines
Instruction
Instruction
Program
Memory
Decoder
Register
Flash
Block Diagram of the AVR Architecture
Program
Counter
and Control
EEPROM
Registrers
I/O Lines
Purpose
General
SRAM
Data Bus 8-bit
Status
32 x 8
Data
ALU
Comparator
I/O Module1
I/O Module 2
I/O Module n
Watchdog
Interrupt
9223B–AVR–09/11
Timer
Analog
Unit
Unit
SPI