Computer Organization CS 206T

Topics

• Introduction

• Historical Background

• Structure & Function

• System Interconnection 2

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Why study computer organization and

architecture?

– Design better programs, including system software such as compilers, operating systems, and device drivers.

– Optimize program behavior.

– Evaluate (benchmark) computer system performance.

– Understand time, space, and price tradeoffs.

1. Introduction

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1.1 Overview

• Computer organization

– Encompasses all physical aspects of computer systems. In other word the internal arrangements of a computer, which includes the design of the processor, memory and input/output circuits

– E.g., circuit design, control signals, memory types.

– How does a computer work? how features are implemented

1. Introduction

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1.1 Overview

• Computer architecture

– those attributes or Logical aspects of system implementation as seen by the programmer. It describes features of a computer family (notably the instructions) and not the specific implementation, just like architecture of a house might be described as Victorian

– E.g., instruction sets, instruction formats, data types, addressing modes.

– How do I design a computer?

– Some do not differentiate between computer organization and computer architecture.

1. Introduction

• 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

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1. Introduction

2. Historical Background

• To fully appreciate the computers of today, it is

helpful to understand how things got the way they

are.

• The evolution of computing machinery has taken

place over several centuries.

• In modern times computer evolution is usually

classified into four generations according to the

salient technology of the era.

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We note that many of the following dates are approximate.

• Generation Zero: Mechanical Calculating Machines

(1642 - 1945)

– Calculating Clock - Wilhelm Schickard (1592 - 1635).

– Pascaline - Blaise Pascal (1623 - 1662).

– Difference Engine - Charles Babbage (1791 - 1871),

also designed but never built the Analytical Engine.

– Punched card tabulating machines - Herman Hollerith

(1860 - 1929).

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Hollerith cards were commonly used for

computer input well into the 1970s.

2. Historical Background

2. Historical Background

• The First Generation: Vacuum Tube Computers

(1945 - 1953)

– Atanasoff Berry Computer (1937 -

1938) solved systems of linear

equations.

– John Atanasoff and Clifford Berry of

Iowa State University.

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2. Historical Background

• The First Generation: Vacuum Tube Computers

(1945 - 1953)

– Electronic Numerical Integrator and

Computer (ENIAC)

– John Mauchly and J. Presper Eckert

– University of Pennsylvania, 1946

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• The ENIAC was the first general-purpose computer.

2. Historical Background

• The First Generation: Vacuum Tube Computers

(1945 - 1953)

– The IBM 650 first mass-produced computer. (1955)

° It was phased out in 1969.

– Other major computer manufacturers of this period

include UNIVAC, Engineering Research Associates

(ERA), and Computer Research Corporation (CRC).

° UNIVAC and ERA were bought by Remington Rand, the

ancestor of the Unisys Corporation.

° CRC was bought by the Underwood (typewriter)

Corporation, which left the computer business.

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2. Historical Background

• The Second Generation: Transistorized

Computers (1954 - 1965)

– IBM 7094 (scientific) and 1401 (business)

– Digital Equipment Corporation (DEC) PDP-1

– Univac 1100

– Control Data Corporation 1604.

– . . . and many others.

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These systems had few architectural similarities.

Transistors • Replaced vacuum tubes

• Smaller

• Cheaper

• Less heat dissipation

• Solid State device

• Made from Silicon (Sand)

• Invented 1947 at Bell Labs

• William Shockley et al.

2. Historical Background

2. Historical Background

• The Third Generation: Integrated Circuit

Computers (1965 - 1980) – IBM 360

– DEC PDP-8 and PDP-11

– Cray-1 supercomputer

– . . . and many others.

• By this time, IBM had gained overwhelming

dominance in the industry.

– Computer manufacturers of this era were characterized as

IBM and the BUNCH (Burroughs, Unisys, NCR, Control

Data, and Honeywell).

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2. Historical Background

• The Fourth Generation: Later Generations

VLSI Computers (1980 - ????)

– large scale integrated circuits (LSI) have 1000

components per chip.

– Very large scale integrated circuits (VLSI) have

more than 10,000 components per chip.

– Ultra very large scale integrated circuits (UVLSI)

have more than 1000,000 components per chip.

– Enabled the creation of microprocessors.

– The first was the 4-bit Intel 4004.

– Later versions, such as the 8080, 8086, and 8088

spawned the idea of “personal computing.”

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2. Historical Background

• Moore’s Law (1965)

– Gordon Moore, Intel founder

– “The density of transistors in an integrated circuit

will double every year.”

• Contemporary version:

– “The density of silicon chips doubles every 18

months.”

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2. Historical Background

• Rock’s Law

– Arthur Rock, Intel financier

– “The cost of capital equipment to build

semiconductors will double every four years.”

– In 1968, a new chip plant cost about $12,000.

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3. 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

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3.1. Function

• All computer functions are:

– Data processing

– Data storage

– Data movement

– Control

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3.1. Operations (1) Data movement

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3.1. Operations (2) Storage

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3.1. Operation (3) Processing from I/O to storage

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3.1.Operation (4) Processing from storage to I/O

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3.2. Structure

• The Computer

– CPU

• Controls the operation of the computer and performs its data processing functions.

– Main memory

• Stores data

– I/O

• Moves data between the computer and its external environment

– System interconnection

• Provides for communication among CPU, main memory, and I/O

3.2. Structure - Top Level

Computer

Main

Memory

Input

Output

Systems

Interconnection

Peripherals

Communication

lines

Central

Processing

Unit

Computer

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3.2. Structure - The CPU

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• Control unit: Controls the operation of the CPU and hence

the computer

• Arithmetic and logic unit (ALU): Performs the computer’s

data processing functions

• Registers: Provides storage internal to the CPU

• CPU interconnection: Some mechanism that provides for

communication among the control unit, ALU, and registers

3.2. Structure - The CPU

Computer Arithmetic

and

Logic Unit

Control

Unit

Internal CPU

Interconnection

Registers

CPU

I/O

Memory

System

Bus

CPU

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3.2. Structure - The Control Unit

CPU

Control

Memory

Control Unit

Registers and

Decoders

Sequencing

Logic

Control

Unit

ALU

Registers

Internal

Bus

Control Unit

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Computer

Components:

Top Level

View

The interconnection structure must support the following types of transfers:

Memory to

processor

Processor reads an

instruction or a unit of data from memory

Processor to

memory

Processor writes a unit

of data to memory

I/O to processor

Processor reads data

from an I/O device via

an I/O module

Processor to I/O

Processor sends data to the I/O

device

I/O to or from

memory

An I/O module is allowed to exchange

data directly with

memory without going

through the processor

using direct memory access

30 4. Components Interconnection

B

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I

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t

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A communication pathway connecting two or more devices

• Key characteristic is that it is a shared transmission medium

Signals transmitted by any one device are available for reception by all other devices attached to the bus

• If two devices transmit during the same time period their signals will overlap and become garbled

Typically consists of multiple communication lines

• Each line is capable of transmitting signals representing binary 1 and binary 0

Computer systems contain a number of different buses

that provide pathways between components at

various levels of the computer system hierarchy

System bus

• A bus that connects major computer components (processor, memory, I/O)

The most common computer interconnection structures

are based on the use of one or more system buses

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Data Bus

Data lines that provide a path for moving data among system

modules

May consist of 32, 64, 128, or more separate lines

The number of lines is referred to as the width of the data bus

The number of lines determines how many bits can be

transferred at a time

The width of the data bus

is a key factor in

determining overall

system performance

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+ Address Bus Control Bus

Used to designate the source or destination of the data on the data bus

If the processor wishes to read a word of data from memory it puts the address of the desired word on the address lines

Width determines the maximum possible memory capacity of the system

Also used to address I/O ports

The higher order bits are used to select a particular module on the bus and the lower order bits select a memory location or I/O port within the module

Used to control the access and the use of the data and address lines

Because the data and address lines are shared by all components there must be a means of controlling their use

Control signals transmit both command and timing information among system modules

Timing signals indicate the validity of data and address information

Command signals specify operations to be performed

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Bus Interconnection Scheme

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Chapter 1: Computer Organization and Architecture: Designing

for Performance,

Chapter1: The Essential of Computer Organization and

Architecture

Chapter 3: Computer Organization and Architecture: Designing

for Performance

That’s all …..