Lecture 1

• Basic structure of computer• History of computer development

Basic structure of computer

Chapter 1

Computer Systems

Is a system that includes computer as one of its components

Computer Organization

Towards the operation units and interconnection which realize computer architecture specification

What is a Computer ?

Electronic device under the instruction and programming control; and execute four basic operation

• input• processing• output• storage

IPOS cycle

IPOS : Input, Processing, Output, Storage

Types of Computer

• Special purpose computer– Eg: Traffic light controller

• General purpose computer– Computer for individual– Computer for organization

Individual Computer

• Professional workstation• Desktop computers• Networked computers (NC)• Notebook computers• Subnotebooks• Personal Digital Assistants (PDA)/

– Handheld computers/ Palmtop

Computer for Organization

• Supercomputer– Fastest– Most expensive

• Mainframe– High speed– More expensive– Process huge amount of data and fast– Support many users– perform server jobs

• Minicomputer – Performance and speed lesser than mainframe

• Server

Computer Systems

• Hardware– Physical component of computer such as

mechanical & electronic circuit which can be touched

• Software– Program which instructs computer to do

something– Consist from bunch of programming, algorithm

and instruction set which can’t be touched

Computer Software

• System software:– All program related to computer operation

coordination • Eg

– Operating System- Windows 98, Mac OS, Unix, Linux, MS Dos

– Utility programs –file management– compiler, interpreter

• Application software– Program that direct computer to do specific task

• text processing (Microsoft Word), mathematical operation (Microsoft Excel), database management.

Personal Computer Hardware

• Component inside microcomputer system

Digital & Analog System

• Digital System - Any system which handle digital signal

(discrete)

• Analog System • Any system which handle analog signal

4 Basic Functional Unit of a Computer

1. Input Unit

• Computer receive coded information from input where the function is to read data

• Example of input device: keyboard, joystick, trackball, mouse.

2. Output Unit

• Its function is to send processed data to be displayed• Output device example:

3. Storage Unit

• Store program and data in extended period of time • Fix• Reliable • Easy – to find and fetch data swiftly

• Compressed storage– Diskettes –500 book pages– Optical Disk –500 books

• Economy– Save in term of physical storage cost – Convenient and fast in filing and access data

Storage type

•Magnetic disk storage

•Optical disk

–Magneto-optical

–CD-ROM

–CD-R

–CD-RW

–DVD-ROM

•Magnetic Tape Storage

Diskette

• Low capacity– small file• Portable• Layered with metallic

substance • Hard plastic jacket for

protection • 3 ½ inch, 1.44 MB

High Capacity Portable Diskette

• Large file• Portable • High capacity

– 120 / 200 MB– Eg: Superdisk

• Zip disk– 250 MB– Not compatible with 3 ½ inch diskette

Hard Disk

• Variety of size (Mb,Gb)• Portable characteristic

– Generally is not portable – Portable hard disk is also available

• Hard scrap layered with metallic material

4. Processing Unit• Central Processing Unit (CPU)• Types of Storage• Program execution • Search data inside memory

• System Unit• Microprocessor • Semiconductor memory • Bus line • Speed and power

Unit Pemprosesan Pusat(CPU)

Central Processing Unit (CPU)

• Change data to information• Control center • One set of electronic circuit which execute stored

instruction program • Two parts

– Control Unit (CU)– Arithmetic Logic Unit (ALU)

Control Unit

• Device which responsile to control• Instruct computer system to execute

program• Communicate with other parts inside a

device

Arithmetic Logic Unit (ALU)

Perrform mathematical operation

Perrform logical operation

Arithmetic Operation

AdditionSubtraction

MultiplicationDivision

Logical Operation

• Evaluate condition• Compare• Can compare

– Numbers– Characters– Specialized character

Register

Special purposeHigh speed

Temporary storageInside CPU

Instruction register

Hold instruction currently being used Data register

Hold data which waiting to be processed

Hold answers from processing outcome

ControlUnit ALU

Register

Memory

Types of Storage• Secondary

– Data which will be used in the end– Long term

• Main Memory– Data which will be used in short period of time – Temporary – Access faster that secondary storage

• Register– Data which related to opeation being execute– Access faster than main memory

Measure storage capacity

KB – kilobyte• 1024 byte• diskette• Cache memory

MB – megabyte• million byte• RAM

GB – gigabyte• Billion bytes• Hard disk• CDs and DVDs

TB – terabytes• Trillion bytes• Large hard disk

Memory

Primary storagePrimary memory

Main storageInternal storageMain memory

Types of memory

RAMRandom Access Memory

ROMRead Only Memory

RAM

• Need electric energy to store data• Not fix• Data and instruction can be read and altered• User always referred to this type of storage

What inside a RAM?

• Operating system• Program that’s running• Data needed by the program• Intermediate answer which wait to be

displayed as output

ROM

• Fix• Instruction to start computer• Data and instuction can be read but can’t be

altered• Mostly, instruction is written in the factory

Execute Program

• Control unit (CU) received one instruction and placed in memory

• CU decode the instruction• CU inform related device to take action• Control in transferred to related device• Task executed• Control returned to CU

Machine Cycle I-time + E-time

Instruction time (I-time)• CU fetch one instruction inside memory and place

in one register• CU decode the instruction and determine the

memory location for the needed data

Machine Cycle

Execution time (E-time)• Execution

– CU moved data from memory to register in ALU– ALU is given the control and execute the instruction– Control is returned to control unit

• CU store operation answer inside memory or register

System Clock

• Clock system produced pulse in a fix rate• Every pulse is one machine cycle• One instruction program actually might be

consist of a number of instruction to the CPU

• Every CPU instruction will take one pulse• CPU has one instruction set – instructions

which it can understand and process

Finding data inside a memory

• Each location inside memory have unique address– Address never change– Content might change

• Memory location can hold one instruction or one data• Programmer used symbolic names

Data representation On/Off

Binary number system represent circuit condition

Bit, Byte, Word

• BIT– Binary DigIT– On/off circuit– 1 or 0

• BYTE– 8 bit– Store one alphanumeric character– 01001010 = J

• WORD– Register size– Number of BIT processed by CPU in one unit– Differ from one computer to another computer (64bit/8

bit)

Coding Scheme• One code to determine which bit group representing which

character on keyboard• ASCII

– Use one byte (8-bit)– 28 = 256 combination or character – Almost all PC and larger computer

• EBCDIC– Use one byte (8-bit)– 28 = 256 combination or character – Used mainly on IBM compatible mainframes

• Unicode– Use two bytes 8-bit (16 bits)– 216 = 65,536 combination or character – Support character for all language in the world– Compatible with ASCII

System Unit• Store electronic component

– Main board – Storage device– Interconnection

• A number of Apple Macintosh have system unit in its monitor

System Unit

Main Board• Microprocessor chip• Memory chip• Interconnection to other

device’s parts• Additional chip -

mathematical processor

System Unit

Storage Device

Hard DriveDisk Drive

CD-ROM DriveDVD-ROM Drive

Microprocessor

• CPU etched on chip• One chip is ¼ x ¼ inci• Consist of silicon• Consist of million gates

– Electric switch that allows electric supply to flow

Microprocesor’s Component

• Control Unit - CU• Arithmetic Logic Unit – ALU• Register• System clock

Development of a better microprocessor

• Microprocessor computer print circuit on microchip– Cheaper– Faster

• Perform other device task– Current mathematical co-processor is part of

microprocessor– Current multimedia instruction is part of

microprocessor

Development of a better microprocessor

• Faster computer execution• Cheaper it is made• More reliable

More functions combined in one microprocessor:

Types of Microprocessor

Intel• Pentium• Celeron • Xeon and Itanium

Compatible Intel• Cyrix• AMD

Types of Microprocessor

• PowerPC– Collabration of Apple, IBM, and Motorola– Used in Apple Macintosh PC group– Inside server and additional system

• Alpha– Produced by Compaq– High power server and workstation

Semiconductor memory

• Reliable• Small • Low cost• Low power consumption • Economically produced in bulk • Not fix• All circuit together become one storage unit that

can’t be separated

Semiconductor memory CMOS

• Complementary metal oxide semiconductor• Use low electric supply• Used inside PC to store device control

needed to start a computer• Store information using power from battery

RAM

• Store instruction and data for current program

• Data inside memory can be randomly accessed

• Easy and fast access• Not fix• Can be erased• Able to be Rewrite

Types of RAM

SRAM (Static RAM)

• Store content when power exist• Faster than DRAM

Types of RAM

DRAM (dynamic RAM)

• Must always refresh• Used in most PC memory because of size and cost• SDRAM

– Faster than DRAM• Rambus DRAM

– Faster than SDRAM– Expensive

Adding RAM

• Buy memory module packaged on circuit board• SIMMS – chip on one side• DIMMS – chip on two sides• Maximum RAM that can be installed is based on

main board design

ROM

• Program and data that has been permanently recorded in factory

• Read only• Can’t be changed by user• Store start computer routine which is

activated when computer is switched on• Fix

PROM

• Programmable ROM • ROM burner can change instruction on

some ROM chip

Bus Line

• Path which transfer electric signal• Bus system

– Transfer data between CPU and memory

• Bas width– Bit data numbers which can carried at one time– Most of the time the same size woth CPU word

• Speed is measured in MHz

Bus Line

CPU can support more and variety of instruction

Larger bus width = More powerful computer

CPU can transfer more data at one time = Faster computer

CPU can refer larger address = More memory can be

used

Expansion Bus

• Connect main board to expansion slot • Attach expansion board to slot

– Interface card – Changeable card

• External connection/port– Serial – Parallel

Expansion Bus

Bus and PC Port

ISA Slow device like mouse and modem

PCI Fast device like hard disk and network card

AGP Connect memmory and graphic card to present faster video

USB Support “daisy-chaining” eliminate the needs to have variety type of expansion card; hot change

IEEE 1394 (FireWire)

High speed bus connects video device with computer

PC Card Credit card size PC card devices mostly found in laptop computer

Speed and power

What make computer fast?

• Microprocssor speed • Bus line size• Cache• Flash memory• RISC type computer• Parallel processing

Computer processing speed

Time to executer one instruction• Millisecond• Microsecond• Nanosecond

– Modern Computer • Picosecond

– In the future

Computer processing speed

• Clock speed– Megahertz (MHz) – Gigahertz (GHz)

• Number of instruction per second• Million Instruction per Second (MIPS)• Complex mathematic operation

– One million operation floating point per second (Megaflop )

Cache

• Small memory block and temporary• Accelerate data transfer• Always used recent instruction and data

Cache

Step 1Processor ask data or instruction

Step 2Go to address in main

memory and read

Step 3Transfer to main CPU and cache

The next processor ask• See first in cache • Go to memory

PROCESSOR

R

A

M

Cache

Types of Cache

• Internal Cache– Level 1 (L1)– Embed in microprocessor – Up to 128KB

• External Cache– Level 2 (L2)– External chip– 256KB or 512 KB– SRAM technology– Cheaper and slower than L1– Faster and more expensive than memory

Flash memory

• RAM that is not change• Used in

– Mobile phone– Digital camera– Digital music recorder– PDA

Instruction set

• CISC Technology• Complex Instruction Set Computing

– Conventional computer – A lot of the instruction is not used

• RISC Technology • Reduce Instruction Set Computing

– Small instruction subset – Increase speed– Program with a number of complex instruction

• Graphic • Engineering

Types of processing

• Serial processing– Executer one instruction at one time – Fetch, decode, execute and store

• Parallel Processing– More than one processor used simultaneously– Can do trillion floating point per second teraflops– Example: Network server, supercomputer

Types of Processing

• Pipelining– instruction do not need to finish before the next is

started– Fetch instruction 1, start to decode and fetch

instruction 2