Microprocessor Chapter 2

AVR

• Advanced Virtual RISC

• Advanced Virtual RAM

• Advanced Virtual ROM

• Advanced Virtual Reality

AVR

• manufactures by ATMEL since 1984

• based on modified Harvard architecture

• based on Von Neumann architecture

• mainly 8-bit microprocessor except for AVR32

ATMega32

• has 32 KB flash memory

• has 4 Ports, i.e. Port A, Port B, Port C and Port D

• 32-bit microprocessor

• Von Neumann architecture

ATMega32 Ports

• has 3 registers, i.e. DDRx, PORTx, and PINx

• DDRx for setting the pin direction

• PORTx for sending data and setting the pull-up resistor

• PINx for receiving data

AVR CPU

• PC stores address of next instruction

• IR stores prefetched instruction

• ID decodes current instruction

• ALU performs learning operation

ATMega32 Programmer Model

• has Data Memory and Program Memory

• has one and shared bus system for Data Memory and Program Memory

• has 32 General Purpose Registers

• 8-bit memory data size