IT Week 3

Week-3 & 4Week-3 & 4The System Unit

Mother Board CMOS, BIOSCMOS, BIOS

Processor Machine Cycle System Clock Multi-Core Processor Basic Unit of Measurement Data Representation Memory

RAM

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System UnitSystem Unit The System Unit is a case which

is just like a box made up of a metalor plastic. This casing actually contain the electronic components of a computerused to process data.

The casing is some time called Chassis The most important component of this

System box is Mother Board. All the components are then installed on this Mother Board.

system unit

system unit

system unit

system unit

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The System UnitThe System Unit What are common components inside the system unit? Processor Memory Adapter cards

Sound card Modem card

Ports Drive bays Power supply

power supply

ports

drive bays

processor

memory

sound card

video cardmodem cardnetwork card

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Mother BoardMother Board It is the main circuit board of

the system unit. It is the centralized platform

where all the hardware componentsof a computer are connected.

Many electronic components are attached to the mother board, others are built-in on it.

The processor chips, memory chips & the other

components on the motherboard consist one or more chip’s.

Most chip’s are not bigger than one-half inch square.

processor chipadapter cards

memory chips

memory slots

motherboard

Expansionslots for adapter cards

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CMOS, BIOSCMOS, BIOS Each and every Motherboard has a small battery cell

“CMOS memory”. It gives to Motherboard a small amount of power to

remember the settings such as hardware configurations, date and time etc

BIOS is kind of software which holds the most important data for machine.

It informs the PC about the compatibility of Motherboard with different hardware components such as CPU etc…

It is the most important component which resides in the ROM CHIP (Read Only Memory) of the Motherboard.

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Mother Board (Cont’d)Mother Board (Cont’d) Small piece of semi-conducting material on which integrated

circuits are etched Two types of packaging for processor

and memory chip’s on desktop computersmotherboard

PGA It holds a larger number of pins,

these pins are mounted on the surface of the package.

DIP It consist two parallel rows of

downward pointing pins that attached to the circuit board.

pin grid array (PGA) package holds processor chips

dual inline packages (DIP) holds memory chips

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ProcessorProcessor The Processor is also called Central Processing Unit (CPU). All the CPUs looks very similar, but they are different in the

way, they have different numbers of pins and different layouts.

The processor significantly impact over all computing power & manages most of computer operations.

On larger computers, such as Mini or Mainframe computers, the various functions performed by the processor extend over many separate chips and often on multiple circuit boards.

On a personal computer, all function of the processor usually are on a single chip.

Some computer manufacturer use the term Microprocessor which refers to a personal computer chip.

Most PC’s today use processors manufactured by IntEL, AMD etc..

“Central Processing Unit (CPU) is an electronic device that interprets and carries out the instructions that operates the

computer.

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Processor (Cont’d)Processor (Cont’d)

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Processor (Processor (Cont’dCont’d)) The combination of Arithmetic Logic Unit and Control Unit is

called as Central Processing Unit (CPU). OR The two main parts of CPU are ALU & CU.

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Processor (Processor (Cont’dCont’d)) ARITHMETIC LOGIC UNIT (ALU)

This component of the computer is responsible for the actual processing.

This component is capable to perform all types of arithmetic operations such as addition, subtraction, multiplication and division etc.

Also it is capable to perform logical operations such as AND, OR etc. it is capable of comparison as well.

The ALU is connected to a set of registers—small & faster memory areas in the CPU, which hold data and program instructions while they are being processed.

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Processor (Processor (Cont’dCont’d)) Registers are the part of the processor, not a part of

memory or storage devices. It contain different type of registers, each with a specific

storage functions. E.g. General purpose registers used for arithmetic operations & data movement. AX, BX, CX, DX

Register function includes Storing the location from where an instruction is

fetched, Storing the location while the CU encode/decode it, Storing data while the ALU compute it and Storing the results after a calculation.

Today, most PCs have 32-bit registers, mean the CPU can process four bytes of data at one time.

Register sizes are rapidly growing to 64 bits.

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Processor (Processor (Cont’dCont’d)) ALU Operations List

Arithmetic Operations

LogicalOperations

+ Add , equal to, not equal to

Subtract >, > greater than, not greater than

x Multiply <, < less than, not less than

Divide , greater than or equal to, not greater than or equal to

^ Raise by a power , less than or equal to, not less than or equal to

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Processor (Cont’d)Processor (Cont’d) CONTROL UNIT (CU)

This unit is responsible for the overall supervision of the computer system.

It does not perform the actual processing but by reading and interpreting the instructions contained in a program, Control Unit (CU) directs other unit of the system to perform a specific task.

Control unit (CU) behaves like a traffic police instructor. It manages the functions performed by different parts of computer.

It controls and coordinates the entire computer system, just the brain directs the human body.

It is responsible to accept data from input device and send it to the memory, from memory to ALU, finally CU sent back the results and store in the memory, until the results are released to an output device.

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Machine CycleMachine Cycle The CPU follows a set of steps-called a machine cycle-for each

instruction it carries out. By using a technique called pipelining, many CPUs can process

more than one instruction at a time. Four operations of the CPU comprise a machine cycle

Step 2. Decode Translate instruction into commands

Processor

Control Unit

Memory

ALU

Step 1. Fetch Obtain program instruction or data item from memory

Step 4. Store Write result to memory

Step 3. Execute Carry out command

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System ClockSystem Clock

Each tick Each tick is a is a

clock cycleclock cycle

Pace of system Pace of system clock is clock is clock speedclock speed

Most clock speeds are Most clock speeds are in the gigahertz (GHz) in the gigahertz (GHz)

range (1 GHz = one range (1 GHz = one billion ticks of system billion ticks of system

clock per second)clock per second)

Processor speed can Processor speed can also be measured in also be measured in

mmillions of illions of iinstructions nstructions pper er ssecond econd (MIPS) or in FLOPs(MIPS) or in FLOPs

Controls timing of all computer operations Generates regular electronic pulses, or ticks, that

set operating pace of components of system unit

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Heat SinkHeat Sink Heat sink—

component with fans that cools processor

heat sink fan

heat sink

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Parallel ProcessingParallel Processing

Control ProcessorControl Processor

Processor 1Processor 1

MemoryMemory


MemoryMemory


MemoryMemory


MemoryMemory

Results combined

Using multiple processors simultaneously to execute a program faster

Requires special software to divide problem and bring results together

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Multi-Core ProcessorMulti-Core Processor A Multi-Core Processor is a processing system composed of two

or more independent cores. The cores are typically integrated onto a single integrated circuit die(known as a chip multiprocessor or CMP).

Core Basic processing area of a computer processor Die A die in the context of integrated circuits is a small block of

semiconducting material, on which a given functional circuit is fabricated.

A medium-scale integrated circuit die

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Multi-Core Processor Multi-Core Processor (Cont’d)(Cont’d)

A Dual-Core and Core 2 Duo Processor contains two cores, and a Quad-Core Processor contains four cores.

A Multi-core processor implements multiprocessing in a single physical package.

Cores in a multi-core device coupled together tightly. Cores may or may not share caches. Dual Core and Core 2 Duo’s are both dual core processor. Core2 duo only takes advantage because The Core 2 Duo has the same L2 cache but it has more cache size

than a Dual core. However, There are architectural changes to the silicon that give the Core 2

Duo more sophisticated processing. The single- and dual-core models are single-die, whereas the

quad-core models comprise two dies, each containing two cores, packaged in a multi-chip module.

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Basic Units Of MeasurementBasic Units Of Measurement BIT

BInary digiT Smallest unit of measurement Two possible values 0 & 1

ON OFF or

BYTE

8 bits

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Data RepresentationData Representation

Recognize only two discrete states: on or off

Use a binary system to recognize two states

Use Number system with two unique digits: 0 and 1, called bits (short for binary digits)

Most computers are digital

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Data Representation Data Representation (Cont’d)(Cont’d)

Eight bits grouped together as a unit Provides enough different combinations of 0s

and 1s to represent 256 individual characters Numbers Uppercase

and lowercase letters

Punctuation marks

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ASCII—American Standard Code for Information Interchange

EBCDIC—Extended Binary Coded Decimal Interchange Code

Unicode—coding scheme capable of representing allworld’s languages

ASCII Symbol EBCDIC

00110000 0 11110000

00110001 1 11110001

00110010 2 11110010

00110011 3 11110011

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How is a letter converted to binary form and back?

Step 1.The user presses the capital letter D (shift+D key) on the keyboard.

Step 2.An electronic signal for the capital letter D is sent to the system unit.

Step 3.The signal for the capital letter D is converted to its ASCII binary code (01000100) and is stored in memory for processing.

Step 4.After processing, the binary code for the capital letter D is converted to an image, and displayed on the output device.

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Basic Units Of Measurement Basic Units Of Measurement ((Processor And Memory Speed))

Millisecond (ms) – a thousandth of a second (1/1,000 = 10-3) Microsecond (µs) - a millionth of a second (1/1,000,000 = 10-6) Nanosecond (ns) – a billionth of a second (1/1,000,000,000 = 10-

9)

Large Units Of Measurement (Memory, Storage) Note: powers of two are used because computer memory and

storage are based on the basic unit (bit). Kilobyte (KB) – a thousand bytes (1,024 = 210) Megabyte (MB) -1,024 KB - a million (1,048,576 = 220) Gigabyte (GB) –1,024 MB - a billion (1,073,741,824 = 230) Terabyte (TB) – a trillion (1,099,511,627,776 = 240)

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Memory The electronic component which provides storage capability to a

computer is called Memory. Memory contains one or more sets of

chips that store data/program instructions need processing, either temporarily or permanently.

All the computers which are used today needs memory or storage capability.

The CPU accesses each location in memory by using a unique number, called the memory address.

Each byte stored in unique location called an address, similar to addresses on a passenger train

Seat #2B4 Seat #2B3

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Memory Memory (Cont’d)(Cont’d)

The are two types of Memory Random Access Memory Read Only Memory

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Random Access MemoryRandom Access Memory RAM is also called volatile memory and Keeps the

information for a shorter period of time because RAM Lost information if powered off or the computer is shutdown.

RAM store data or instructions, the computer then uses these instructions to perform any processing work.

The contents of RAM change rapidly and often. Typical ranges from Mega Bytes to Giga Bytes Random Access means direct access to any part of memory

The more RAM a The more RAM a computer has, the computer has, the faster it respondsfaster it responds

Also called Also called main memorymain memory

or or primary primary storagestorage

Most RAM is Most RAM is volatilevolatile, it is lost , it is lost when computer’s when computer’s

power is power is turned offturned off

Memory chips that can be Memory chips that can be read from and written read from and written

to by processorto by processor

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How do program instructions transfer in and out of How do program instructions transfer in and out of RAM?RAM?

Step 1. When you start the computer, certain operating system files load into RAM from the hard disk. The operating system displays the user interface on the screen.

Operating system Operating system instructionsinstructions

Operating system Operating system interfaceinterface

RAM

RAM

Web browser Web browser program instructions program instructions

are removed from are removed from RAMRAM

Web browser Web browser window no longer window no longer

is displayed on is displayed on desktopdesktop

Step 2. When you start a word processing program, the program’s instructions load into RAM from the hard disk. The word processing program, along with the Web Browser and certain operating system instructions are in RAM. The word processing program window is displayed on the screen.

Step 3. When you quit a program, such as the Web browser, its program instructions are removed from RAM. The Web browser no longer is displayed on the screen.

Word processing Word processing program program instructionsinstructions

Word processing Word processing program windowprogram window

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Where does Memory Reside?Where does Memory Reside?

Resides on small Resides on small circuit board called circuit board called memory modulememory module

Memory slotsMemory slots on on motherboard hold motherboard hold memory modulesmemory modules

memory chip memory slot

dual inline memory module

IT Week 3

Technology

Transcript of IT Week 3