Chapter 1Introduction

Architecture & Organization 1

• Architecture is those attributes visible to the programmer—Instruction set, number of bits used for data

representation, I/O mechanisms, addressing techniques.

—e.g. Is there a multiply instruction?

• Organization is how features are implemented—Control signals, interfaces, memory

technology.—e.g. Is there a hardware multiply unit or is it

done by repeated addition?

Architecture & Organization 2

• All Intel x86 family share the same basic architecture

• The IBM System/370 family share the same basic architecture

• This gives code compatibility—At least backwards

• Organization differs between different versions

Structure & Function

• Structure is the way in which components relate to each other

• Function is the operation of individual components as part of the structure

Function

• All computer functions are:—Data processing—Data storage—Data movement—Control

Functional View

• The computer must be able to process data. The data could be in a variety of forms.

• It is also essential that the computer can store data.

• The computer could also able to move data between itself and the outside worl.

• The computer must control the process, storing data and move data.

Operations (a) Data movement

Operations (b) Storage

Operation (c) Processing from/to storage

Operation (d)Processing from storage to I/O

Structure - Top Level

Computer

Main Memory

InputOutput

SystemsInterconnection

Peripherals

Communicationlines

CentralProcessing Unit

Computer

Structure - The CPU

Computer Arithmeticand Login Unit

ControlUnit

Internal CPUInterconnection

Registers

CPU

I/O

Memory

SystemBus

CPU

• Control Processing Unit: control the operation of the computer and performs its data processing functions, often simply referred to a processor.

• Main memory : stores data.• I/O: moves data between the computer

and its external environment.• System Interconnection: There should be

a mechanism for communication among CPU, main memory, I/O.

Structure - The Control Unit

CPU

ControlMemory

Control Unit Registers and Decoders

SequencingLogin

ControlUnit

ALU

Registers

InternalBus

Control Unit

• Major structural components:—Control Unit: controls the operations of the

CPU and hence the computers.—ALU: Performs the computer’s data processing

functions.—Registers: Provides storage internal to the

CPU.—CPU interconnection: probably the best

example is bus system.