AN INTRODUCTION TO COMPUTER ARCHITECTURE

DAT 10403

CHAPTER 1

LEARNING OUTCOMES

Reference

Computer Organization and Architecture Designing for Performance by William Stallings

WHY STUDY COMPUTER ARCHITECTURE IEEE/ACM Computer Science Curriculum

2008

By IEEE (Institute of Electrical and Electronics Engineers) Computer Science and ACM (Association for Computing Machinery)

Students need to understand computer architecture in order to make best use of the software tools and computer languages they used to create programs.

INTRODUCTION

COMPUTER ORGANIZATION & ARCHITECTURE

Refers to attributes of a system visible to a programmer (attributes that have a direct impact on the logical execution of a program)

Examples : Instruction set, data types (numbers, characters), I/O mechanism & techniques for addressing memory.

Refers to the operational units & their interconnections that realize the architectural specifications.

Examples : Hardware, interfaces between computer and peripherals & memory technology used

COMPUTER OPERATION CYCLE

COMPUTER FUNCTIONS

Computer must be able to :-

COMPUTER OPERATIONS

Simply transferring data from one peripheral or communication line to the other

Data transferred from the external environment to computer storage (read) and vice versa (write)

Data processing en route between storage and the external environment

• Function as a data movement device.

• Simply transferring data from one peripheral or communication line to another.

TYPES OF COMPUTER OPERATIONS

MOVEMENT

CONTROL

STORAGE PROCESSING

1. Data Movement Operation

•Function as a data storage device, with data transferred from the external environment to computer storage (read) and vice versa (write).

TYPES OF COMPUTER OPERATIONS

MOVEMENT

CONTROL

STORAGE PROCESSING

2. Read/Write Operation

MOVEMENT

CONTROL

STORAGE

PROCESSING

MOVEMENT

CONTROL

STORAGE

PROCESSING

COMPUTER OPERATIONS [S.William 2003)

3. Process/Storage Operation 4. Process Storage/External Environment

Operations involving data processing, on data either in storage (3) or en route between storage and the external environment (4)

SYSTEM INTERCONNECTION

COMPUTER STRUCTURE [S. William,

2003]

COMPUTER

CPUMAIN

MEMORY

INPUTOUTPU

T

COMPUTERPERIPHERALS

COMMUNICATION LINES

COMPUTER STRUCTURE

CPU STRUCTURE Major structural components of CPU:

CPU INTERCONNECTIONS [S. William, 2003]

REGISTERS ALU

CONTROL

UNIT

COMPUTER

CPUI/O SYS.BUS

MEMORY

CPU

INTERNAL CPU

INTERCONNECTI

ON

A BRIEF HISTORY OF COMPUTERS

• born: 12/26/1791

• son of a London banker

• Trinity College, Cambridge

• Lucasian Professorship

• Mathematician and Scientist

Charles Babbage (1791-1871) THE FATHER OF COMPUTER

Difference Engine

• 1822 plan for calculating and printing mathematical tables like they were used in the navy

• using the method of difference, based on polynomial functions

Difference Engine

• 1822design 6 decimal places with second-order difference

• 1830engine with 20 decimal places and a sixth-order difference

• 1834plans for an improved device, capable of calculating any mathematical function

• increase of calculating speed

• never completed

Analytical Engine

Analytical Engine - Architecture

separation of storage and calculation: store mill

control of operations by microprogram: control barrels

user program control using punched cards operations cards variable cards number cards

more than 200 columns of gear trains and number wheels

16 column register (store 2 numbers) 50 register columns, with 40 decimal digits

of precision counting apparatus to keep track of

repetitions cycle time: 2.5 seconds to transfer a

number from the store to a register in the mill

addition: 3 seconds conditional statements

Analytical Engine

Analytical Engine

First programmer – Ada Lovelace

Ada Lady Lovelace, daughter of Lord Byron, was working with Babbage on the Analytical Engine

first ideas of algorithm representation programming languages

already realized: program loops conditional statements

COMPUTER HISTORY

It has become widely accepted to classify computers into generations based on the fundamental hardware technology employed.

Each new generation is characterized by greater processing performance, larger memory capacity, and smaller size than the previous one.

COMPUTER GENERATIONS

Generation

Approximate Dates

Technology Typical Speed

(Operations per second)

1 1946 – 1957 Vacuum Tube 40,000

2 1958 – 1964 Transistor 200,000

3 1965 – 1971 Integrated Circuit 1,000,000

4 1972 – 1977 Large Scale Integration

10,000,000

5 1978 – 1991 Very large Scale Integration

100,000,000

6 1992 - Ultra large Scale Integration

1,000,000,000

Moore’s Law

Increased density of components on chip Gordon Moore - cofounder of Intel Number of transistors on a chip will double every year Since 1970’s development has slowed a little

Number of transistors doubles every 18 months Cost of a chip has remained almost unchanged Higher packing density means shorter electrical

paths, giving higher performance Smaller size gives increased flexibility Reduced power and cooling requirements Fewer interconnections increases reliability

FIRST GENERATION

Vacuum Tubes - 1941 - 1957

First Generation Electronic Computers used Vacuum Tubes

Vacuum tubes are glass tubes with circuits inside.

Vacuum tubes have no air inside of them, which protects the circuitry.

Vacuum tube

Vacuum Tubes - 1941 - 1957

Vacuum Tubes - 1941 - 1957

Vacuum Tubes - 1941 - 1957

ENIAC

first fully electronic digital computer built in the U.S.

Created at the University of Pennsylvania

ENIAC weighed 30 tons contained 18,000

vacuum tubes Cost a paltry $487,000

IAS Computer Memory of IAS consists of 1000 storage

locations. Both Data and Instructions are stored there. Numbers are represented in binary form. Each instruction is a binary code. Each number is represented by a 39 bit

value. With each instruction consisting of an 8-bit

operation code (opcode)

ENIAC Electronic Numerical Integrator And Computer A decimal rather than a binary machine.

Numbers were represented in a decimal form.

used stored-program concept. A program could be represented in a form suitable for

storing in memory alongside data.

Design of a new stored-program computer called IAS computer. Main memory Arithmetic Logic Unit (ALU) Control Unit Input/Output (I/O)

First Computer Bug - 1945

Relay switches part of computers

Grace Hopper found a moth stuck in a relay responsible for a malfunction

Called it “debugging” a computer

First Generation Computers

•Used the vacuum tubes technology for calculation as well as for storage and control purpose.

Advantages: (1) Fastest computing devices of their time; (2) These computers were able to execute complex

mathematical problems in an efficient manner.

Disadvantages:(1) The functioning of these computers depended on the machine language.(2) There were generally designed as special-purpose computers. (3) The use of vacuum tube technology make these computers very large and bulky. (4) They were not easily transferable from one place to another due to their huge size and also required to be placed in cool places.(5) They were single tasking because they could execute only one program at a time.(6) The generated huge amount of heat and hence were prone to hardware faults.

First Generation Computers

Too bulky i.e large in size

First Generation Computers

Vacuum tubes burn frequently

First Generation Computers

SECOND GENERATION

First Transistor

Uses Silicon developed in 1948 won a Nobel prize on-off switch

Second Generation Computers used Transistors, starting in 1956

Transistor

1 2

Transistor board

Second Generation Computers

• Use transistors in place of vacuum tubes in building the basic logic circuits.

Advantages: (1) Fastest computing devices of their time; (2) Easy to program because of the use assembly

language;(3) Could be transferred from one place to other very

easily because they were small and light; (4) Require very less power in carrying out their

operations; (5) More reliable, did not require maintenance at regular

intervals of time.

Disadvantages: (1)The input and output media were not improved to a considerable extent(2) Required to be placed in air-conditioned places(3) The cost of these computers was very high and they were beyond the reach of home users(4) Special-purpose computers and could execute only specific applications.

Second Generation Computers

THIRD GENERATION

IC (integrated circuit)

ICs (integrated circuits)

IC (integrated circuit)

Third Generation Computers

• Use of Integrated Circuits

Advantages: (1) Fastest computing devices; (2) Very productive; (3) Easily transportable from one place to another

because of their small size; (4) Use high-level languages; (5) Could be installed very easily and required less

space; (6) Can execute any type of application. (7) More reliable and require less frequent maintenance

schedules.

Disadvantages:(1)The storage capacity of these computers was still very small;(2) The performance of these computers degraded while executing large applications, involving complex computations because of the small storage capacity;(3) The cost of these computers was very high;(4) They were still required to be placed in air-conditioned places.

Third Generation Computers

FOURTH GENERATION

Birth of Personal Computers - 1975

256 byte memory (not Kilobytes or Megabytes)

2 MHz Intel 8080 chips

Just a box with flashing lights

cost $395 kit, $495 assembled.

The MITS Altair 8800 is a microcomputer designed in 1974 based on the Intel 8080 CPU.

Fourth Generation Computers

•Use of Large Scale Integration technology and Very Large Scale Integration technology

•The term Personal Computer (PC) became known to the people during this era.

Advantages: (1) Very powerful in terms of their processing speed and access time; (2) Storage capacity was very large and faster;(3) Highly reliable and required very less maintenance;(4) User-friendly environment; (5) Programs written on these computers were highly portable; (6) Versatile and suitable for every type of applications;(7) Require very less power to operate.

Fourth Generation Computers

Disadvantages: (1) The soldering of LSI and VLSI chips on the wiring board was not an easy task and required complicated technologies to bind these chips on the wiring board;(2) The working of these computers is still dependent on the instructions given by the programmer.

Fourth Generation Computers

FIFTH GENERATION

Fifth Generation Computers

•The different types of modern digital computers come under this category.

•Use Ultra Large Scale Integration technology that allows almost ten million electronic components to be fabricated on one small chip.

Advantages: (1) Fastest and powerful computers till date; (2) Being able to execute a large number of applications at the same time and that too at a very high speed; (3) Decreasing the size of these computers to a large extent; (4)The users of these computers find it very comfortable to use them because of the several additional multimedia features; (5) They are versatile for communications and resource sharing.

Fifth Generation Computers

LATER GENERATIONS

1990s: Pentiums and Power Macs

Early 1990s began penetration of computers into every niche: every desk, most homes, etc.

Faster, less expensive computers paved way for this

Windows 95 was first decent GUI for “PCs” Macs became more PC compatible - easy file

transfers Prices have plummeted

$2000 for entry level to $500 $6000 for top of line to $1500

21st Century Computing

Great increases in speed, storage, and memory

Increased networking, speed in Internet

Widespread use of CD-RW PDAs Cell Phone/PDA WIRELESS!!!

Pentium Evolution (1) 8080

first general purpose microprocessor 8 bit data path Used in first personal computer – Altair

8086 much more powerful 16 bit instruction cache, prefetch few instructions 8088 (8 bit external bus) used in first IBM PC

80286 16 Mbyte memory addressable up from 1Mb

80386 32 bit Support for multitasking

Pentium Evolution (2) 80486

sophisticated powerful cache and instruction pipelining

built in maths co-processor Pentium

Superscalar Multiple instructions executed in parallel

Pentium Pro Increased superscalar organization Aggressive register renaming branch prediction data flow analysis speculative execution

Pentium Evolution (3) Pentium II

MMX technology graphics, video & audio processing

Pentium III Additional floating point instructions for 3D graphics

Pentium 4 Note Arabic rather than Roman numerals Further floating point and multimedia enhancements

Itanium 64 bit

Core i7 Xeon See Intel web pages for detailed information on

processors

What’s next for computers?

Use your imagination to come up with what the next century holds for computers. What can we expect in two years? What can we expect in twenty years?