Chapter 1 Introduction

Contents Organization & Architecture Structure & Function

Computer Architecture Organization and architecture Bear: “The design of the integrated system which provides a useful tool to the programmer” Hayes: “The study of the structure, behavior and design of computers” Abd-Alla: “The design of the system specification at a general or subsystem level” Foster: “The art of designing a machine that will be a pleasure to work with” Hennessy and Patterson: “The interface between the hardware and the lowest level software”

Computer Architecture Organization and architecture Common themes Design/structure Art System Tool for programmer and application Interface Thus, computer architecture refers to those attributes of the system that are visible to a programmer-- those attributes that have a direct impact on the execution of a program Instruction sets Data representation Addressing I/O

Architecture & Organization Organization and architecture 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 Organization and architecture 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 A computer is a complex system Structure and function A computer is a complex system A description of complex system is to recognize the hierarchic nature of most complex systems The hierarchic nature of complex systems is essential to their design and description The behavior at each level depends only on a simplified, abstracted characterization of the system at the next lower level

Structure & Function Structure and 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 Structure and function All computer functions are: Data processing Data storage Data movement Control

Functional view Functional view of a computer Storage Facility Data Structure and function Functional view of a computer Data Movement Apparatus Control Mechanism Storage Facility Processing

Operations e.g. keyboard to screen Data movement Storage Facility Data Structure and function Data movement e.g. keyboard to screen Data Movement Apparatus Control Mechanism Storage Facility Processing

Operations e.g. Internet download to disk Storage Storage Facility Structure and function Storage e.g. Internet download to disk Data Movement Apparatus Control Mechanism Storage Facility Processing

Operations e.g. updating bank statement Processing from/to storage Structure and function Processing from/to storage e.g. updating bank statement Data Movement Apparatus Control Mechanism Storage Facility Processing

Operations e.g. printing a bank statement Structure and function Processing from storage to I/O e.g. printing a bank statement Data Movement Apparatus Control Mechanism Storage Facility Processing

Structure Outline of the book The computer is an entity that interacts in some fashion with its external environment

Top-Level Structure Top-Level structure Central processing unit (CPU) Main memory I/O System interconnection

Top-Level Structure Peripherals Central Main Processing Memory Unit Structure and function Computer Main Memory Input Output Systems Interconnection Peripherals Communication lines Central Processing Unit

The Central Processing Unit(CPU) Structure and function Computer Arithmetic and Login Unit Control Unit Internal CPU Interconnection Registers CPU I/O Memory System Bus

The Control Unit Control Unit Arithmetic CPU and Registers Login Unit Structure and function CPU Arithmetic and Login Unit Control Unit Internal CPU Interconnection Registers ALU Internal Bus Control Unit