Computer Architecture

Prologue

1

Topics • Computer Architecture

• Computer Organization

• Organization vs. Architecture

• History of Computers

• Generations of Computers

• M’LMoore’s Law

2 Computer Architecture (1) • Definition? • “The desigggyn of integrated system which provides a useful tool to the programmer.” (Baer) • “The study of the structure, behaviour, and design of computers.” (Hayes) • “The design of the system specification at a general or subsystem level.” (Abd-Alla) • “The art of desigggning a machine that will be a pleasure to work with.” (Foster)

3

Computer Architecture (2) • “The interface between the hardware and the lowest level software.” ((yHennessy and Patterson)

• Keywords: —Design —System —Structure —Art TlTool IfInterface

4 Computer Architecture (3) • Therefore, computer architecture refers to —Attributes of a system visible to programmers —Attributes that have a direct impact on the execution of programs

• Attributes —Instruction set —Data representation —I/O mechanisms —Addressing techniques

5

Computer Organization • Organization refers to operational units and their interconnections that realize the architectural specifications.

• Attributes: hardware details transparent to programmers —Control signals —Computer/peripheral interface —MthlMemory technology

6 Architecture vs. Organization (1) • Architecture is attributes visible to programmers • Organization is how features are implemented • Example: —Architecture: multiply instruction? —Organization: hardware multiply unit or done by repeated addition? (how is it implemented?) • Example: —IBM/370 architecture —different models (organizations)

7

Architecture vs. Organization (2) • Family Concept —All Intel x86 family share the same basic architecture —The IBM System/370 family share the same basic architecture —This gi ves cod e compatibili ty ( at l east b ack ward s)

• OiidiffbOrganization differs between diff erent versi ons

8 History of Computers (1) • Pre-mechanical Era —Abacus (ancient China) • Mechanical Era (1623 – 1940s) —Wilhelm Schickhard (1623) – Automatically +, -, x,  —Blaise Pascal (1642) – Mass produced first working machine (50) – Only +, - —Gottfried Liebniz (1673) – Impp(,roved on Pascal’s machine (+, -,,, x, )

9

History of Computers (2) • Mechanical Era (cont’d) —Charles Babbagg(e (1822) – Father of modern computer – Automatic computation of math tables – Any math operation – Punch cards – Modern structure: I/O, storage, ALU – +: 1 sec. x: 1 min. —George Boole (1847) – Mathmatical analysis of logic

10 History of Computers (3) • Mechanical Era (cont’d) —Herman Hollerith (()1889) – Modern day punch card machine – Tabulating machine company b predecessor of IBM —Konard Zuse (1938) – First working mechanical computer, Z1 (later on Z2 – Z4) – First programmable computer – Binary floating point machine —Howard Aiken (1943) – Harvard Mark I, built by IBM – Implementation of Babbage’s machine

11

History of Computers (4) • Summary of Mechanical Era —Contributions – Reduce calculation time – Increase accuracy —Drawback – Speed: limited by moving parts – Cumbersome – Expensive – Unreliable • Entered the Electronic Era (1945 – present)!!

12 von Neumann/Turing • Stored Program concept • Main memoryygpg storingprograms and data • ALU operating on binary data • Control unit interpreting instructions from memory and executing • Input and output equipment operated by control unit • Princeton Institute for Advanced Studies —IAS • Completed 1952: Basis for virtually every machine designed since then

13

Structure of von Neumann machine

14 Generations of Computer • First generation: Vacuum tube - 1946-1957 • Second generation: Transistor - 1958-1964 • Third generation: Integrated circuits – 1965 – 1971 —SllliSmall scale integrati on - 1965 on – Up to 100 devices on a chip —Medium scale integration - to 1971 – 100-3,000 devices on a chip —Semiconductor memory (1970) —Microprocessor (1971)

15

Generations of Computer • Fourth generation: Large scale integration (LSI) - 1971-1977 —3,000 - 100,000 devices on a chip —Intel 8080: first general-purpose microprocessor (1974) • Fifth generation: 1978 – present —Very large scale integration (VLSI) - 1978 to date – 100,000 - 100,000,000 devices on a chip —Ultra large scale integration (ULSI) – Over 100,000,000 devices on a chip —GSI ??

16 Moore’s Law • Increased density of components on chip • 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, ggggpiving higher performance • Smaller size gives increased flexibility • Reduced power and cooling requirements • Fewer iiinterconnections

increases reliability 17