INTRODUCTION TO COMPUTER ORGANIZATION

COURSE CODE : IAS 2123COURSE NAME : COMPUTER ORGANIZATIONLECTURER : MDM ROZIYANI HAJI SETIKHP NO : 019-6181835/019-3170659EMAIL : roziyani@unisel.edu.my

TYPICAL COMPUTER AD

Is the computer fast enough to run necessary programs?

Is the computer cost-effective?

Will it be obsolete in 6 months?

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WHY STUDY COMPUTER ORGANIZATION?

User

• Understand system capabilities and limitations• Make informed decisions• Improve communications with information technology professionals

Systems Analyst

• Conduct surveys, determine feasibility and define and document user requirements

• Specify computer systems to meet application requirements

Programmer

• Create efficient application software for specific processing needs

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WHY STUDY COMPUTER ORGANIZATION?

System Administrator / Manager• Install, configure, maintain, and upgrade computer

systems• Maximize system availability• Optimize system performance• Ensure system security

Web Designer• Optimize customer accessibility to Web services• System administration of Web servers• Select appropriate data formats• Design efficient Web pages

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INPUT-PROCESS-OUTPUT MODEL (IPO)

•Input: keyboard, mouse, scanner, punch cards

•Processing: CPU executes the computer program

•Output: monitor, printer, fax machine

•Storage: hard drive, optical media, diskettes, magnetic tape

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DIFFERENCE BETWEEN COMPUTER ORGANIZATION AND COMPUTER ARCHITECTURE

Computer Architecture

• Attributes of a system visible to a programmer or those attributes that have direct impact on the logical execution of program

• Eg. Instruction set, no. of bit used to represent various data types (no., characters), I/O mechanism, techniques for addressing memory

• Eg. of Issue: Whether a computer will have multiply instruction• Many computer manufacturer offers a family of computer

model with same architecture but with differences organization, with different price and different performance.

• Eg. IBM System/370 Architecture

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COMPUTER ORGANIZATION

• Study on • internal computer systems such as the hardware

resources available, • the function and the objective of the resources and

their relationship.• Focusing on

• the organization and relationship between computer physical resources,

• the integration of the system function, and the communication and data flow controlling between the physical component.

• Operational units and their interconnections that realize the architectural specification and hardware detail transparent to the programmers (William Stalling,1996)

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EXAMPLE• control signals, interfaces between the computer and peripheral, and the memory technology used

• Issue: • Whether that instruction will be implemented

by a special multiply unit. • Organizational decision may be based on

the anticipated frequency of use of the multiply instruction, the speed between two approaches, the cost and physical size of a special multiply unit.

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COMPUTER ORGANIZATION

helps optimize performance-based products.

For example, software engineers need to know the processing ability of processors. They may need to optimize software in order to gain the most performance at the least expense. This can require quite detailed analysis of the computer organization.

For example, in a multimedia decoder, the designers might need to arrange for most data to be processed in the fastest data path.

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CONT..Computer organization also helps plan the selection of a processor for a particular project.

Multimedia projects may need very rapid data access, while supervisory software may need fast interrupts.

Sometimes certain tasks need additional components as well. For example, a computer capable of virtualization needs virtual memory hardware so that the memory of different simulated computers can be kept separated.

The computer organization and features also affect the power consumption and the cost of the processor

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ARCHITECTURE COMPONENTS

Hardware• Processes data by executing instructions• Provides input and output

Software• Instructions executed by the system

Data• Fundamental representation of facts and observations

Communications• Sharing data and processing among different systems

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HARDWARE COMPONENT

Input/Output devices

Storage Devices

CPU

• ALU: arithmetic/logic unit• CU: control unit• Interface unit

Memory

• Short-term storage for CPU calculations

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TYPICAL PERSONAL COMPUTER SYSTEM

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1. Scanner2. CPU (Microprocessor)3. Primary storage (RAM)4. Expansion cards (graphics cards, etc.)5. Power supply6. Optical disc drive7. Secondary storage (Hard disk)8. Motherboard9. Speakers10.Monitor11.System software12.Application software13.Keyboard14.Mouse15.External hard disk16.Printer

CPU: CENTRAL PROCESSING UNIT

ALU: arithmetic/logic unit• Performs arithmetic and Boolean logical calculations

CU: control unit• Controls processing of instructions• Controls movement of data within the CPU

Interface unit• Moves instructions and data between the CPU and other hardware components

• Bus: bundle of wires that carry signals and power between different components

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MEMORY

Also known as primary storage, working storage, and RAM (random access memory)

Consists of bits, each of which hold a value of either 0 or 1 (8 bits = 1 byte)

Holds both instructions and data of a computer program (stored program concept)

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SOFTWARE COMPONENTApplications

Operating System

• API: application program interface

• File management

• I/O

• Kernel

• Memory management

• Resource scheduling

• Program communication

• Security

• Network Module

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COMMUNICATIONS COMPONENT

Hardware

• Communication channels• Physical connections between computer systems• Examples: wire cable, phone lines, fiber optic cable,

infrared light, radio waves• Interface hardware

• Handles communication between the computer and the communication channel

• Modem or network interface card (NIC)Software

• Network protocols: HTTP, TCP/IP, ATAPI

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COMPUTER SYSTEMS

All computer systems, no matter how complex,

consists of the following:

At least one CPU

Memory to hold programs and data

I/O devices

Long-term storage

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PROTOCOLSCommon ground rules of communication between computers, I/O devices, and many software programs

Examples

• HTTP: between Web servers and Web browsers• TCP/IP: between computers on the Internet and local area

networks• ATAPI: between a CPU and CD-ROMs

AT Attachment with Packet Interface

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ATAPI

standard interface used to connect storage devices drives inside personal computers

ATA connector on the left, with two motherboard ATA connectors on the right.

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STANDARDS

Created to ensure universal compatibility of data formats and protocols

May be created by committee or may become a de facto standard through popular use

Examples:• Computer languages: Java, SQL, C, JavaScript• Display standards: Postscript, MPEG-2, JPEG, GIF• Character set standards: ASCII, Unicode, EBCDIC• Video standards: VGA, XGA, RGB

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EARLY HISTORY

1642: Blaise Pascal invents a calculating machine

1801: Joseph Marie Jacquard invents a loom that uses punch cards

1800’s:

• Charles Babbage attempts to build an analytical engine (mechanical computer)

• Augusta Ada Byron develops many of the fundamental concepts of programming

• George Boole invents Boolean logic.

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EARLY COMPUTERS

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Babbage’s Analytical Engine

ENIAC

PROGRAMMABLE: PUNCH CARDSJOSEPH JACQUARD (1752-1834): PUNCH CARD LOOM

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punch card tabulator

MODERN COMPUTER DEVELOPMENT1937: Mark I is built (Aiken, Harvard University, IBM).

• First electronic computer using relays.1939: ABC is built

• First fully electronic digital computer. Used vacuum tubes.1943-46: ENIAC (Mauchly, Eckert, University of Pennsylvania).

• First general purpose digital computer.1945: Von Neumann architecture proposed.

• Still the standard for present day computers.1947: Creation of transistor

• (Bardeen, Shockley, Brattain, Bell Labs).1951: UNIVAC.

• First commercially available computer.

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VON NEUMANN ARCHITECTURE

Three key concepts:

• Data and instruction are stored in a single read-write memory

• The content of this memory are addressable by location, without regard to the type of data contained there

• Execution occurs in a sequential fashion (unless explicitly modified) from one instruction to the next

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CPU is the central processor unit (Arithmetic unit), ROM is a read only memory, RAM is a random access memory and the I/O-units are the input- and output devices

THE VON NEUMANN COMPUTER ARCHITECTURE MODEL

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VIRTUAL MACHINE CONCEPT

Virtual Machines

Specific Machine Levels

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VIRTUAL MACHINESTanenbaum: Virtual machine concepta virtual machine (VM) is a software

implementation of a machine (computer) that executes programs like a real machine.

[Popek and Goldberg] an efficient, isolated duplicate of a real machine. Current use includes virtual machines which have no direct correspondence to any real hardware

An essential characteristic of a virtual machine is that the software running inside is limited to the resources and abstractions provided by the virtual machine—it cannot break out of its virtual world.

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VIRTUAL MACHINES

Programming Language analogy:◦Each computer has a native machine language

(language L0) that runs directly on its hardware◦A more human-friendly language is usually constructed

above machine language, called Language L1

Programs written in L1 can run two different ways:◦Interpretation – L0 program interprets and executes L1

instructions one by one◦Translation – L1 program is completely translated into an L0

program, which then runs on the computer hardware

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TRANSLATING LANGUAGES

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English: Display the sum of A times B plus C.

C++: cout << (A * B + C);

Assembly Language:

mov eax,Amul Badd eax,Ccall WriteInt

Intel Machine Language:

A1 00000000

F7 25 00000004

03 05 00000008

E8 00500000

VIRTUAL MACHINE LEVELS

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HIGH-LEVEL LANGUAGE

Level 5

Application-oriented languages

• C++, Java, Pascal, Visual Basic . . .Programs compile into assembly language (Level 4)

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ASSEMBLY LANGUAGE

Level 4 Instruction mnemonics that have a one-to-one

correspondence to machine language Calls functions written at the operating system level

(Level 3) Programs are translated into machine language (Level 2)

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OPERATING SYSTEM

Level 3

Provides services to Level 4 programs

Translated and run at the instruction set architecture level (Level 2)

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INSTRUCTION SET ARCHITECTURE

Level 2

Also known as conventional machine language

Executed by Level 1 (microarchitecture) program

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MICROARCHITECTURE

Level 1

Interprets conventional machine instructions (Level 2)

Executed by digital hardware (Level 0)

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DIGITAL LOGIC

Level 0 CPU, constructed from digital logic gates System bus Memory Implemented using bipolar transistors

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