mis theory section ii(hardware)

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Stage II, ICMAPStage II, ICMAP 11

Computer HardwareComputer Hardware

Section Section -- IIII


ComputerComputer

Stage II, ICMAPStage II, ICMAP 33 Stage II, ICMAPStage II, ICMAP 44

The System UnitThe System Unit

�� Houses the electronic components of the Houses the electronic components of the

computer systemcomputer system

�� MotherboardMotherboard

�� Storage devicesStorage devices

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MotherboardMotherboard

�� Flat circuit board that holds Flat circuit board that holds

the computer circuitrythe computer circuitry

�� Central processing unit Central processing unit

((microprocessormicroprocessor) is most ) is most

important componentimportant component

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MotherboardMotherboard


MicroprocessorMicroprocessor

�� Central processing unit etched Central processing unit etched

on silicon chipon silicon chip

�� Contain tens of millions of tiny Contain tens of millions of tiny

transistorstransistors

�� Key components:Key components:

�� Central processing unitCentral processing unit

�� RegistersRegisters

�� System clockSystem clock

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DieDie of an of an Intel 80486DX2Intel 80486DX2 microprocessor (actual microprocessor (actual

size: 12×6.75size: 12×6.75 mm) in its packaging.mm) in its packaging.

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Microcomputer ProcessorsMicrocomputer Processors

�� IntelIntel

�� Leading manufacturer of processorsLeading manufacturer of processors

�� Intel 4004 was worlds first microprocessorIntel 4004 was worlds first microprocessor

�� IBM PC powered by Intel 8086IBM PC powered by Intel 8086

�� Current processorsCurrent processors

•• CentrinoCentrino

•• ItaniumItanium

•• Pentium IVPentium IV

•• XeonXeon


Microcomputer ProcessorsMicrocomputer Processors

�� Advanced Micro Devices (AMD)Advanced Micro Devices (AMD)

�� Main competitor to IntelMain competitor to Intel

�� Originally produced budget productsOriginally produced budget products

�� Current products outperform IntelCurrent products outperform Intel

�� Current processorsCurrent processors

•• SempronSempron

•• Athlon FX 64Athlon FX 64

•• Athlon XPAthlon XP


Comparing ProcessorsComparing Processors

�� Speed of processorSpeed of processor

�� Size of cacheSize of cache

�� Number of registersNumber of registers

�� Bit sizeBit size

�� Speed of Front side busSpeed of Front side bus


TransistorsTransistors

�� Electronic switches that may or may not Electronic switches that may or may not

allow electric current to pass throughallow electric current to pass through

�� If current passes through, switch is on, If current passes through, switch is on,

representing a 1 bitrepresenting a 1 bit

�� Otherwise, switch is off, representing a 0 bitOtherwise, switch is off, representing a 0 bit

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Types of ChipsTypes of Chips

�� Intel makes a family of processorsIntel makes a family of processors�� Pentium III and Pentium4 processors in most PCsPentium III and Pentium4 processors in most PCs

�� Celeron processor sold for lowCeleron processor sold for low--cost PCscost PCs�� Xeon and Itanium for highXeon and Itanium for high--end workstations and end workstations and

network serversnetwork servers

�� Other processorsOther processors�� Cyrix and AMD make IntelCyrix and AMD make Intel--compatible compatible

microprocessorsmicroprocessors

�� PowerPC chips used primarily in Macintosh PowerPC chips used primarily in Macintosh computerscomputers

�� Compaq’s Alpha microprocessor used in highCompaq’s Alpha microprocessor used in high--end end serversservers


Central Processing Unit Central Processing Unit -- CPUCPU

�� CPU consists of electronic circuits that CPU consists of electronic circuits that

interpret and execute program instructions interpret and execute program instructions

and communicate with the input, output and communicate with the input, output

and storage device. and storage device.

�� CPU is a highly complex, extensive set of CPU is a highly complex, extensive set of

electronic circuitry that executes stored electronic circuitry that executes stored

program instruction.program instruction.


Secondary Storage Device

Central Processing Unit Central Processing Unit -- CPUCPU

Primary storage device

CU ALU

Input device Output device

Central Processing Unit-CPU


Central Processing Unit Central Processing Unit -- CPUCPUCPU consists of two parts.CPU consists of two parts.

1.1. Control unitControl unit--CUCU

2.2. Arithmetic/logical unit Arithmetic/logical unit --ALUALU

Control Unit:Control Unit:

�� How does the input know that it is the time for How does the input know that it is the time for it to feed data into the storage unit?it to feed data into the storage unit?

�� How does the ALU know, what should be done How does the ALU know, what should be done with the data once it is received ?with the data once it is received ?

�� How could the final result be sent to the output How could the final result be sent to the output device ?device ?

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Control unit Control unit -- CUCU

�� All this is possible due to the control unit of All this is possible due to the control unit of the computer system. the computer system.

�� The control unitThe control unit--CU contains circuitry that CU contains circuitry that uses electrical signals to direct the entire uses electrical signals to direct the entire computer system to carry out, or execute computer system to carry out, or execute store program instruction.store program instruction.

�� The CU does not execute program The CU does not execute program instruction; rather, it directs other parts of instruction; rather, it directs other parts of the system to do so.the system to do so.


Arithmetic/Logic Unit Arithmetic/Logic Unit ––ALUALU

�� ALU is digital circuit that perform arithmetic ALU is digital circuit that perform arithmetic operation like(+, operation like(+, --, X, /) and logical operation like , X, /) and logical operation like (OR, AND, NOT, <, > etc)(OR, AND, NOT, <, > etc)

�� ALU performs these operations at very high ALU performs these operations at very high speed.speed.

�� ALU consists of number of registers and adders.ALU consists of number of registers and adders.

�� RegistersRegisters are a number of small, highare a number of small, high--speed speed memory. They hold various types of information memory. They hold various types of information such as data, instructions, addresses and the such as data, instructions, addresses and the

intermediate results of calculationsintermediate results of calculations

�� AnAn adderadder is a is a digital circuit that performs that performs additionaddition of numbers. In modern of numbers. In modern computerscomputersadders reside in the ALU.adders reside in the ALU.


How the CPU Executes InstructionsHow the CPU Executes Instructions

�� Four steps performed for each instructionFour steps performed for each instruction

�� Fetch Fetch

�� Decode Decode

�� ExecuteExecute

�� StorageStorage

Each CPU has its own instruction setEach CPU has its own instruction set

�� those instructions that CPU can understand those instructions that CPU can understand

and executeand execute


The Machine CycleThe Machine Cycle

�� The time required to The time required to retrieve, execute, and retrieve, execute, and store an operationstore an operation

�� ComponentsComponents�� Instruction timeInstruction time

�� Execution timeExecution time

�� System clock System clock synchronizes synchronizes operationsoperations

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Instruction TimeInstruction Time

�� Also called IAlso called I--timetime

�� Control unit gets instruction from memory Control unit gets instruction from memory

and puts it into a registerand puts it into a register

�� Control unit decodes instruction and Control unit decodes instruction and

determines the memory location of needed determines the memory location of needed

datadata

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Execution TimeExecution Time

�� Control unit moves data from memory to Control unit moves data from memory to

registers in ALUregisters in ALU

�� ALU executes instruction on the dataALU executes instruction on the data

�� Control unit stores result of operation in Control unit stores result of operation in

memory or in a registermemory or in a register

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PipeliningPipelining

�� Feeds a new instruction into CPU at each step Feeds a new instruction into CPU at each step

of the machine cycleof the machine cycle

�� Instruction 2 fetched when instruction 1 is being Instruction 2 fetched when instruction 1 is being

decoded, rather than waiting until cycle is completedecoded, rather than waiting until cycle is complete

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Microprocessor SpeedsMicroprocessor Speeds

�� Measure of system clock speed Measure of system clock speed

�� How many electronic pulses the clock How many electronic pulses the clock

produces per secondproduces per second

�� Usually expressed in gigahertz (GHz) Usually expressed in gigahertz (GHz)

•• Billions of machine cycles per secondBillions of machine cycles per second

•• Some old PCs measured in megahertz (MHz)Some old PCs measured in megahertz (MHz)

�� Comparison of clock speed only Comparison of clock speed only

meaningful between identical meaningful between identical

microprocessorsmicroprocessors

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Other Performance MeasuresOther Performance Measures

�� Millions of Instructions per Second (MIPS)Millions of Instructions per Second (MIPS)

�� HighHigh--speed personal computers can perform speed personal computers can perform

over 500 MIPSover 500 MIPS

�� Typically a more accurate measure of Typically a more accurate measure of

performance than clock speedperformance than clock speed

�� Megaflop: one million floatingMegaflop: one million floating--point point

operationsoperations

�� Measures ability of computer to perform Measures ability of computer to perform

complex mathematical operationscomplex mathematical operations


Representing DataRepresenting Data

�� BitBit

�� ByteByte (8(8--bits)bits)

�� WordWord (16(16--bits)bits)

�� DwordDword (32(32--bits)bits)

�� Quad Word /Paragraph (64Quad Word /Paragraph (64--bits)bits)


BitBit

�� Short for binary digitShort for binary digit

�� Two possible values: 0 and 1Two possible values: 0 and 1

�� Can never be emptyCan never be empty

�� Basic unit for storing dataBasic unit for storing data

�� 0 means off, 1 means on0 means off, 1 means on

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ByteByte

�� A group of 8 bitsA group of 8 bits

�� Each byte has 256 (2Each byte has 256 (288) possible values) possible values

�� For text, stores one characterFor text, stores one character

�� Can be letter, digit, or special characterCan be letter, digit, or special character

�� Memory and storage Memory and storage devices measured in devices measured in

number of bytesnumber of bytes

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CPU’s Word Size CPU’s Word Size

�� The number of bits the CPU processes as The number of bits the CPU processes as

a unita unit

�� Equal to the width of accumulator registerEqual to the width of accumulator register

�� Typically a whole number of bytesTypically a whole number of bytes

�� The larger the word, the more powerful the The larger the word, the more powerful the

computercomputer

�� Personal computers typically 32 or 64 bits in Personal computers typically 32 or 64 bits in

lengthlength

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……MemoryMemory

�� Storage capacity of memory is measured in Storage capacity of memory is measured in bytes.bytes.

�� A Collection of 8 bits is called byte.A Collection of 8 bits is called byte.

8 bits=1 Byte8 bits=1 Byte

1 KB=1024 Bytes (21 KB=1024 Bytes (21010) )

1 MB=1KB * 1024 (21 MB=1KB * 1024 (22020) )

1 GB= 1 MB * 1024 (21 GB= 1 MB * 1024 (23030) )

1 TB = 1 GB * 1024 (21 TB = 1 GB * 1024 (24040) )

1 PB = I TB *1024 (21 PB = I TB *1024 (25050) )

�� Types of memory areTypes of memory are

�� Random Access MemoryRandom Access Memory--RAMRAM

�� Read Only MemoryRead Only Memory--ROMROM


Data RepresentationData Representation

�� Computers understand two Computers understand two

things: on and offthings: on and off

�� Data represented in binary formData represented in binary form

�� Binary (base 2) number systemBinary (base 2) number system

�� Contains only two digits, 0 and 1Contains only two digits, 0 and 1

•• Corresponds to two states, on and offCorresponds to two states, on and off


Coding SchemesCoding Schemes

�� Provide a common way of representing a Provide a common way of representing a

character of datacharacter of data

�� Needed so computers can exchange dataNeeded so computers can exchange data

�� Common SchemesCommon Schemes

�� ASCIIASCII

�� EBCDICEBCDIC

�� UnicodeUnicode

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ASCIIASCII

�� Stands for “American Standard Code for Stands for “American Standard Code for

Information Interchange”Information Interchange”

�� Most widely used standardMost widely used standard

�� Used on virtually all personal computersUsed on virtually all personal computers

�� Uses 7Uses 7--8 bits to represent one character8 bits to represent one character

�� 128128--256 possible values256 possible values


EBCDICEBCDIC

�� ““Extended Binary Coded Decimal Extended Binary Coded Decimal

Interchange Code”Interchange Code”

�� Used primarily on IBM and IBMUsed primarily on IBM and IBM--compatible compatible

mainframesmainframes

�� Uses 8 bits to represent one characterUses 8 bits to represent one character

•• 256 possible values256 possible values

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UnicodeUnicode

�� Designed to accommodate alphabets of Designed to accommodate alphabets of

more than 256 charactersmore than 256 characters

�� Uses 16 bits to represent one characterUses 16 bits to represent one character

�� 65,536 possible values65,536 possible values

�� Requires twice as much space to store Requires twice as much space to store

datadata

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The CPU and MemoryThe CPU and Memory

�� CPU cannot process data from disk or input CPU cannot process data from disk or input devicedevice�� It must first reside in memoryIt must first reside in memory

�� Control unit retrieves data from disk and moves it into Control unit retrieves data from disk and moves it into memorymemory

�� Items sent to ALU for processingItems sent to ALU for processing�� Control unit sends items to ALU, then sends back to Control unit sends items to ALU, then sends back to

memory after processingmemory after processing

�� Data and instructions held in memory until sent Data and instructions held in memory until sent to an output or storage device or program is shut to an output or storage device or program is shut downdown

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Temporary Storage AreasTemporary Storage Areas

�� RegistersRegisters

�� MemoryMemory


RegistersRegisters

�� HighHigh--speed temporary storage areasspeed temporary storage areas

�� Storage locations located within the CPUStorage locations located within the CPU

�� Work under direction of control unitWork under direction of control unit

�� Accept, hold, and transfer instructions or dataAccept, hold, and transfer instructions or data

�� Keep track of where the next instruction to be Keep track of where the next instruction to be

executed or needed data is storedexecuted or needed data is stored

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RegistersRegisters

�� Registers are a number of small, volatile, Registers are a number of small, volatile, highhigh--speed memory. speed memory.

�� Registers are temporary memory units that Registers are temporary memory units that store store wordswords..

�� The registers are located in the The registers are located in the processor, instead of in processor, instead of in RAMRAM. .

�� So data can be accessed and stored So data can be accessed and stored faster.faster.


RegisterRegister

�� They hold various types of information They hold various types of information

such as data, instructions, addresses and such as data, instructions, addresses and

the intermediate results of calculations. the intermediate results of calculations.

�� Registers work under the direction of Registers work under the direction of

control unitcontrol unit--CU to accept, hold and CU to accept, hold and

transfer instructions or data and perform transfer instructions or data and perform

arithmetic or logical comparison at a very arithmetic or logical comparison at a very

high speed.high speed.

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Types of RegistersTypes of Registers

�� Memory Access RegisterMemory Access Register--MAR:MAR: it holds it holds the addresses of instruction being the addresses of instruction being currently accessed by the CPU.currently accessed by the CPU.

�� Memory Buffer RegisterMemory Buffer Register--MBR: MBR: It holds It holds the contents of data or instruction read the contents of data or instruction read from, or written in memory (RAM)from, or written in memory (RAM)

�� Instruction Pointer RegisterInstruction Pointer Register--IPR: IPR: It It points to the memory location that hold the points to the memory location that hold the instruction/data that is to be executed next instruction/data that is to be executed next by the CPUby the CPU


Types of Registers Types of Registers �� Instruction RegisterInstruction Register--IR:IR: holds current holds current

instruction which is being executed.instruction which is being executed.

�� PC: PC: Program Counter. Stores the address Program Counter. Stores the address

of the of the macromacro--instructioninstruction currently being currently being

executed. executed.

�� ((MacroMacro--IntructionIntruction--An An intructionintruction stored in stored in RAMRAM))

�� Input/Output RegisterInput/Output Register--I/OI/O: this register is : this register is

used to communicate with the I/O devices.used to communicate with the I/O devices.


Types of Types of RegistersRegisters

�� Stack Control RegisterStack Control Register: A stack : A stack represents a set of memory blocks . Data represents a set of memory blocks . Data is stored in FILO order.is stored in FILO order.

�� Flag RegisterFlag Register: Flag register is used to : Flag register is used to indicate occurrence of a certain condition indicate occurrence of a certain condition during and operation of the CPUduring and operation of the CPU

�� ACAC Accumulator. Stores a previously Accumulator. Stores a previously calculated value or a value loaded from calculated value or a value loaded from the main memorythe main memory


MemoryMemory

�� Memory is the part of computer that holds data Memory is the part of computer that holds data or instruction before and after the processingor instruction before and after the processing

�� Memory is also called primary storage, primary Memory is also called primary storage, primary memory, main storage or main memorymemory, main storage or main memory�� Often expressed as randomOften expressed as random--access memory (RAM)access memory (RAM)

�� Not part of the CPUNot part of the CPU

�� Stores information only as long as the program Stores information only as long as the program is in operationis in operation

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Memory AddressesMemory Addresses

�� Each memory location has Each memory location has an addressan address�� A unique number, much like A unique number, much like

a mailboxa mailbox

�� Data in RAM has an addressData in RAM has an address

�� CPU reads data using the CPU reads data using the addressaddress

�� CPU can read any addressCPU can read any address

�� May contain only one May contain only one instruction or piece of datainstruction or piece of data�� When data is written back to When data is written back to

memory, previous contents of memory, previous contents of that address are destroyedthat address are destroyed


Types of MemoryTypes of Memory

�� Semiconductor MemorySemiconductor Memory

�� RAM and ROMRAM and ROM

�� Flash MemoryFlash Memory

�� Cache MemoryCache Memory


Semiconductor MemorySemiconductor Memory

�� Used by most modern computersUsed by most modern computers

�� Reliable, inexpensive, and compactReliable, inexpensive, and compact

�� Volatile: requires continuous electric currentVolatile: requires continuous electric current

•• If the current is interrupted, data is lostIf the current is interrupted, data is lost

�� Complementary Metal Oxide Semiconductor Complementary Metal Oxide Semiconductor

(CMOS)(CMOS)

•• Retains information when power is shut downRetains information when power is shut down

•• Used to store information needed when the Used to store information needed when the

computer bootscomputer boots


CMOSCMOS

�� Stands for “Complementary Metal Oxide Stands for “Complementary Metal Oxide

Semiconductor”Semiconductor”

�� CMOS CMOS memorymemory to hold the date, time, and to hold the date, time, and

systemsystem setupsetup parametersparameters like disk drives, like disk drives,

keyboard, mouse etc. keyboard, mouse etc.

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RAM and ROMRAM and ROM

�� Random Access Memory Random Access Memory (RAM)(RAM)

�� ReadRead--Only Memory Only Memory (ROM)(ROM)

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Random Access MemoryRandom Access Memory--RAMRAM

�� RAM is the most common type of memory found RAM is the most common type of memory found

in in computerscomputers and other and other devicesdevices, such as , such as

printersprinters..

�� memory can be accessed randomly in an easy memory can be accessed randomly in an easy

and fast manner, no matter where it is.and fast manner, no matter where it is.

�� Its contents are lost once the power is shut off.Its contents are lost once the power is shut off.

�� And therefore, it is also called volatile memory. And therefore, it is also called volatile memory.


RAMRAM


Random Access MemoryRandom Access Memory

�� Data can be Data can be

accessed randomly accessed randomly

�� Memory address 10 Memory address 10

can be accessed as can be accessed as

quickly as memory quickly as memory

address 10,000,000address 10,000,000

�� Types:Types:

�� Static RAM Static RAM (SRAM)(SRAM)

�� Dynamic RAM Dynamic RAM (DRAM)(DRAM)

�� Packaged on circuit Packaged on circuit

boardsboards

�� Single inSingle in--line memory line memory

modules (SIMMS)modules (SIMMS)

�� Dual inDual in--line memory line memory

modules (DIMMS)modules (DIMMS)

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Random Access MemoryRandom Access Memory--RAMRAM�� There are two types or RAMThere are two types or RAM

1.1. Dynamic Random Access MemoryDynamic Random Access Memory--DRAMDRAM

2.2. Static Random Access MemoryStatic Random Access Memory--SSRAMRAM

ExpensiveExpensive3. Cheaper3. Cheaper

which makes it faster which makes it faster 2. which makes it slower 2. which makes it slower

Static RAM does not need Static RAM does not need

to be refreshedto be refreshed

1.Dynamic RAM needs to be 1.Dynamic RAM needs to be

refreshedrefreshed thousands of times per thousands of times per

secondsecond

SRAMSRAMDRAMDRAM


Dynamic RAMDynamic RAM

�� Must be continuously refreshed by CPU or Must be continuously refreshed by CPU or

it loses its contentsit loses its contents

�� Used for personal computer memoryUsed for personal computer memory

�� Synchronous DRAM (SDRAM): faster type of Synchronous DRAM (SDRAM): faster type of

DRAM used todayDRAM used today

�� RambusRambus DRAM (RDRAM): faster than DRAM (RDRAM): faster than

SDRAM, will become more commonly used SDRAM, will become more commonly used

as price declinesas price declines

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Static RAMStatic RAM

�� Retains its contents with intervention from Retains its contents with intervention from

CPUCPU

�� Faster and more expensive than DRAMFaster and more expensive than DRAM

�� Typically used for Level 2 cacheTypically used for Level 2 cache

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Memory ModulesMemory Modules--RAMRAM

�� SIMMSIMM--single insingle in--line memory moduleline memory module

�� DIMMDIMM--Double inDouble in--line memory moduleline memory module

�� RambusRambus inin--line memory moduleline memory module

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ReadRead--Only MemoryOnly Memory

�� Contains programs and data permanently Contains programs and data permanently

recorded into memory at the factoryrecorded into memory at the factory

�� Cannot be changed by userCannot be changed by user

�� Not volatile: contents do not disappear when Not volatile: contents do not disappear when

power is lostpower is lost

�� Data on ROM can be changed using ROM Data on ROM can be changed using ROM

burner.burner.

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ReadRead--Only MemoryOnly Memory

�� When PC is turn ON, the boot routine is When PC is turn ON, the boot routine is

activated from ROMactivated from ROM

�� Basic Input Output System (BIOS)Basic Input Output System (BIOS)

•• Power On Self Test (POST)Power On Self Test (POST)

•• Loading Operating System from Hard disk into Loading Operating System from Hard disk into

RAMRAM


Types of ROM Types of ROM

�� PROM PROM (Programmable Read only Memory)(Programmable Read only Memory)

�� EPROM EPROM (Erasable Programmable ROM)(Erasable Programmable ROM)

�� EEPROM EEPROM (Electrically Erasable Programmable (Electrically Erasable Programmable

ROM)ROM)

�� Programmable ROM (PROM) chipsProgrammable ROM (PROM) chips�� Instructions on chip can be changedInstructions on chip can be changed


Flash MemoryFlash Memory

�� Nonvolatile RAMNonvolatile RAM

�� Used in cellular phones, digital cameras, and Used in cellular phones, digital cameras, and

some handheld computerssome handheld computers

�� Flash memory chips resemble credit cardsFlash memory chips resemble credit cards

�� Smaller than disk drive and require less Smaller than disk drive and require less

powerpower

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Cache MemoryCache Memory

A cache is a temporary storage area A cache is a temporary storage area

where frequently accessed data can be where frequently accessed data can be

stored for rapid accessstored for rapid access

�� Faster than RAMFaster than RAM

�� Used between RAM and processor.Used between RAM and processor.

�� Types of Cache MemoryTypes of Cache Memory

�� L1 CacheL1 Cache�� builtbuilt--in into micro processorin into micro processor

�� L2 CacheL2 Cache�� resides on mother boardresides on mother board


Cache memoryCache memory

�� Very fast memoryVery fast memory

�� Holds common or recently used dataHolds common or recently used data

�� Speeds up computer processingSpeeds up computer processing

�� Most computers have several cachesMost computers have several caches

�� L1 holds recently used dataL1 holds recently used data

�� L2 holds upcoming dataL2 holds upcoming data

�� L3 holds possible upcoming dataL3 holds possible upcoming data


The BUSThe BUS

�� Collection of wires through which Collection of wires through which datadata is is

transmitted from one part of a transmitted from one part of a computercomputer to to

another. another.

�� The term The term busbus usually refers to usually refers to internal businternal bus. This . This

is a bus that connects all the internal computer is a bus that connects all the internal computer

components to the components to the CPUCPU and and main memorymain memory. .

�� There's also an There's also an expansion busexpansion bus that enables that enables

expansion boardsexpansion boards to access the CPU and to access the CPU and

memory memory


TheThe BUSBUS

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The BusThe Bus

�� Parallel electrical paths that transport data Parallel electrical paths that transport data between the CPU and memorybetween the CPU and memory

�� Typically the same as CPU’s word sizeTypically the same as CPU’s word size

�� With a larger bus size, CPU can:With a larger bus size, CPU can:�� Transfer more data at a timeTransfer more data at a time

•• Makes computer fasterMakes computer faster

�� Bus widthBus width�� The number of electrical paths to carry dataThe number of electrical paths to carry data�� Measured in bitsMeasured in bits

�� Bus speedBus speed�� Measured in megahertz (MHz)Measured in megahertz (MHz)


Classification of BusClassification of Bus

�� Internal BusesInternal Buses�� AddressAddress

�� DataData

�� ControlControl

�� External Buses( Add peripheral devices to External Buses( Add peripheral devices to system)system)�� Expansion BoardExpansion Board / Slots /Adapter Cards/ Slots /Adapter Cards

�� PortPort

�� Common expansion busesCommon expansion buses


TheThe BUSBUS�� The data bus transfers actual dataThe data bus transfers actual data

�� The address bus transfers information The address bus transfers information

about where the data should go. about where the data should go.

�� The size of a bus, known as its The size of a bus, known as its width,width, is is

important because it determines how important because it determines how

much data can be transmitted at one time. much data can be transmitted at one time.

For example, a 16For example, a 16--bitbit bus can transmit 16 bus can transmit 16

bits of data, whereas a bits of data, whereas a 3232--bitbit bus can bus can

transmit 32 bits of data. transmit 32 bits of data.


External BusesExternal Buses

�� Add peripheral devices to systemAdd peripheral devices to system

�� Expansion boardExpansion board

�� PortPort

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Expansion Slots and BoardsExpansion Slots and Boards

�� Allows users to configure the machineAllows users to configure the machine

�� Slots allow the addition of new devicesSlots allow the addition of new devices

�� Devices are stored on cardsDevices are stored on cards

�� Computer must be off before insertingComputer must be off before inserting


Expansion BoardsExpansion Boards

�� Connect to expansion Connect to expansion

slots on motherboardslots on motherboard

�� Used to connect Used to connect

peripheral devicesperipheral devices

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Common Expansion Buses and PortsCommon Expansion Buses and Ports

�� Industry Standard Architecture (ISA) busIndustry Standard Architecture (ISA) bus�� Used for slow devices such as the mouse and modemUsed for slow devices such as the mouse and modem

�� Peripheral Component Interconnect (PSI) busPeripheral Component Interconnect (PSI) bus�� Used for faster devices such as hard disksUsed for faster devices such as hard disks

�� Accelerated Graphics Port (AGP)Accelerated Graphics Port (AGP)�� Provides faster video performanceProvides faster video performance

�� Universal Serial Bus (USB) portUniversal Serial Bus (USB) port�� Allows you to convert many devices in a series into the USB portAllows you to convert many devices in a series into the USB port

�� IEEE 1394 busIEEE 1394 bus�� A highA high--speed bus normally used to connect video equipmentspeed bus normally used to connect video equipment

�� PC Card busPC Card bus�� Used on laptops to plug in a creditUsed on laptops to plug in a credit--card sized devicecard sized device

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Industry Standard Architecture Industry Standard Architecture

(ISA)(ISA)

�� External bus standardsExternal bus standards

�� Local busLocal bus

�� Peripheral control interfacePeripheral control interface

�� Accelerated graphics portAccelerated graphics port

�� Universal serial busUniversal serial bus

�� IEEE 1394 (FireWire)IEEE 1394 (FireWire)

�� PC CardPC Card

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Peripheral control interface (PCI)Peripheral control interface (PCI)

�� Connects modems and sound cardsConnects modems and sound cards

�� Found in most modern computersFound in most modern computers


Accelerated Graphics Port (AGP)Accelerated Graphics Port (AGP)

�� Connects video card to motherboardConnects video card to motherboard

�� Extremely fast busExtremely fast bus

�� Found in all modern computersFound in all modern computers


Universal Serial Bus (USB)Universal Serial Bus (USB)

�� Connects external devicesConnects external devices

�� Hot swappableHot swappable

�� Allows up to 127 devicesAllows up to 127 devices

�� Cameras, printers, and scannersCameras, printers, and scanners


FireWireFireWire

�� IEEE 1384IEEE 1384

�� Cameras and video equipmentCameras and video equipment


�� Port is very expensivePort is very expensive

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PC CardPC Card

�� Used on laptopsUsed on laptops


�� Devices are the size of a credit cardDevices are the size of a credit card


PC CardsPC Cards

�� Expansion bus for laptopsExpansion bus for laptops

�� PCMCIAPCMCIA


�� Small card sizeSmall card size

�� Three types, I, II and IIIThree types, I, II and III

�� Type II is most commonType II is most common


PortsPorts

�� External connectors to plug in peripherals External connectors to plug in peripherals such as printerssuch as printers

�� Two types of portsTwo types of ports�� Serial: transmit data one bit at a timeSerial: transmit data one bit at a time

•• Used for slow devices such as the mouse and Used for slow devices such as the mouse and keyboardkeyboard

�� Parallel: transmit groups of bits together sideParallel: transmit groups of bits together side--byby--sideside•• Used for faster devices such as printers and Used for faster devices such as printers and

scannersscannersReturn


Standard Computer PortsStandard Computer Ports

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PortPort

�� In computer hardware, a In computer hardware, a portport serves as an serves as an

interface between the computer and other interface between the computer and other

computers or devices. computers or devices.

�� Physically, a port is a specialized Physically, a port is a specialized outletoutlet on a piece on a piece

of equipment to which a of equipment to which a plugplug or or cablecable connects connects


Types of Types of PortPort

�� Serial portsSerial ports send and receive one bit at a send and receive one bit at a

time via a single wire pair and used for slow time via a single wire pair and used for slow

speed devises speed devises e.ge.g keyboard, mouse etc. keyboard, mouse etc.

�� Parallel portsParallel ports send multiple (8) bits at the send multiple (8) bits at the

same time over several sets of wires. same time over several sets of wires.


Serial CommunicationsSerial Communications


Parallel CommunicationsParallel Communications

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Parallel CommunicationsParallel Communications


USB PortUSB Port

�� USBUSB-- Universal Serial BusUniversal Serial Bus

-- USB is a "plug and play" interface between a computer USB is a "plug and play" interface between a computer and addand add--on devices such camera and microphone.on devices such camera and microphone.

-- With USB, a device can be added to your computer With USB, a device can be added to your computer without having to turn the computer off and therefore it is without having to turn the computer off and therefore it is called “Hot swappable”called “Hot swappable”

�� Supports up to 127 devicesSupports up to 127 devices

-- USB supports a data speed of 12 megabit per second. USB supports a data speed of 12 megabit per second. This speed will accommodate MPEG video cameras.This speed will accommodate MPEG video cameras.


USB HubUSB Hub

�� A single USB port can be used to connect A single USB port can be used to connect

up to 127 peripheral devices, such as up to 127 peripheral devices, such as

mice, modems, and keyboards mice, modems, and keyboards


Universal Serial Bus (USB)Universal Serial Bus (USB) PortPort

�� Up to 127 devices can connect to the host, Up to 127 devices can connect to the host, either directly or by way of USB hubs. either directly or by way of USB hubs.

�� Individual USB cables can run as long as 5 Individual USB cables can run as long as 5 meters; with hubs, meters; with hubs,

�� devices can be up to 30 meters (six cables' devices can be up to 30 meters (six cables' worth) away from the host.worth) away from the host.

�� USB 1 Released in September 1998 & slow USB 1 Released in September 1998 & slow speed speed

�� With USB 2(released in April 2000),the bus has With USB 2(released in April 2000),the bus has a maximum data rate of 480 megabits per a maximum data rate of 480 megabits per second and called “Hisecond and called “Hi--speed”speed”

23


Male ConnectorMale Connector

1.1.The part bearing one or more pins, or The part bearing one or more pins, or

which fits inside the other which fits inside the other

2.2.A connector with pins that fit into the A connector with pins that fit into the

sockets of a female connector. sockets of a female connector.


Female ConnectorFemale Connector�� A A female connectorfemale connector is a is a connectorconnector attached to a attached to a

wire, cable, or piece of hardware, having one or wire, cable, or piece of hardware, having one or

more recessed holes with electrical terminals more recessed holes with electrical terminals

inside, inside, ......


SCSISCSI

�� Small Computer System InterfaceSmall Computer System Interface

�� Supports dozens of devicesSupports dozens of devices

�� External devices daisy chainExternal devices daisy chain

�� Fast hard drives and CDFast hard drives and CD--ROMsROMs


Our PakistanOur Pakistan

�� Pakistan is the most connected country in South Asia , with the Pakistan is the most connected country in South Asia , with the highest teledensityhighest teledensity

�� · · Pakistan's communications costs are lower than any other countryPakistan's communications costs are lower than any other country in the region in the region �� · · Pakistan has the Pakistan has the world's largest biometric databaseworld's largest biometric database (NADRA); this system (not the data)(NADRA); this system (not the data) is now is now

being provided to allied countries being provided to allied countries

�� · · Pakistan has the Pakistan has the world's largest WiMAX networkworld's largest WiMAX network

�� · · Pakistan has one of the Pakistan has one of the world's most aggressive Fibreworld's most aggressive Fibre--toto--thethe-- Home (FTTH) rolloutsHome (FTTH) rollouts

�� · · Pakistan has one of the highest rates of cellular connectivity gPakistan has one of the highest rates of cellular connectivity growth in the world (According to rowth in the world (According to PTA 2007's report the rate of growth in Pakistan 's mobile sectoPTA 2007's report the rate of growth in Pakistan 's mobile sector is fourth highest in the world) r is fourth highest in the world)

�� · · Pakistan Pakistan was the winner of the 2007 GSM industry association awardwas the winner of the 2007 GSM industry association award

�� · · · · With WLL (CDMA), WiMAX, GSM and FTTH, Pakistan is pretty much leWith WLL (CDMA), WiMAX, GSM and FTTH, Pakistan is pretty much leading the pack in ading the pack in terms of diversity and breadth of connectivity terms of diversity and breadth of connectivity

�� · · The world's The world's youngest Microsoft Certified Professional is a Pakistani youngest Microsoft Certified Professional is a Pakistani and so if the and so if the world's world's youngest Cisco CCNA professionalyoungest Cisco CCNA professional

�� · · Pakistani students Pakistani students excelled in MIT's global software talent competitionexcelled in MIT's global software talent competition

�� · · Citations of Citations of Pakistani scientific publications are rising sharplyPakistani scientific publications are rising sharply

�� · · Over two dozen Over two dozen Pakistani scientists are working on the Large Hadron ColliderPakistani scientists are working on the Large Hadron Collider; the grandest ; the grandest experiment in the history of Physicsexperiment in the history of Physics

�� http://www.microsoft.com/SURFACE/http://www.microsoft.com/SURFACE/videos.htmlvideos.html

mis theory section ii(hardware)

Technology