Cs ch3

Full form of cpu

Central Processing Unit

purpose of cpu

to fetch, decode , excute and it has responsibility for processing of all instruction and data in computer application

what is micropocerssor

is a type of integated circuit on single chip

von neumann architecture consist of what

CU, ALU, resister, buses

function of ALU

1. carries out mathematical operation Eg + - * /

2. carries out logical operation - help computer to make certain decisions such as AND, OR, NOT.

3. it can have more than 1 input

Function of CU

1. how data moves around the CPU by sending signal to control the movement of data

2. decode instruction fetched from memory

type of resister

CIR(current Instruction resister )

PC( program counter)

MAR(memory address register)

MDR(memory data resister)

ACC(Accmulator)

funtion of CIR

store current instruction being decode and execute

funtion of pc

holds memory address where next instruction to be read and can be found

funtion of MAR

store address of memory location currntly being read form

function of MDR

store data which just been read from memory

Function of ACC

Store result of calculation that have taken place in ALU

Name 3 type of buses

1. Address bus

2. Data bus

3. Control bus

Function of address bus

Carries lactation data

Function of data bus

Carries data or instructions

Function of control bus

Carries signal from CU to all other computer components

Fetch decode execute cycle step

1. program counter point to next intruction

2. instruction fetched from memory into MAR then MDR

3. instruction decoded in CIR

4. ALU executes instruction and result store in accumulator

Name the factor affecting CPU speed

Clock and core

Describe clock speed

Refer to the number of electrical pulses

When increasing clock speed it increases 3.5GHz

Describe over clock

Use clock speed higher than the computer was designed for

Describe the problem of over clock

1. Instructions cannot complete in time before next one

2. Overheating of CPU

Function of core

Allow multiple register

Using more core increases clock speed

Dual core has 2 channel

Quad core has 4 channel

Decribe cache

Faster access to the cpu

Store frequently

It has instruction before accessing to ram

What is instruction set

• Set of comman intruction

• command are machine code

List of command in instruction set

Add - value store in ACC

Subtact - Subtact value from ACC

Load - Sore in memory location into accumulator

Store - Store value in accumulator in specific location in memory

Stop - Stop the program

What is embedded system

• perform dedicated function

• Use firmware

• Eg: Coffee machine, Traffic light, washing machines

Property of embedded system

Small in size

Use less power

What is input device

• hardware component that allows data to be entered into a computer system

• is it required because it allow user to interact and provide the data

Name of input device

1. Keyboard

2. Optical mouse

3. Touch screen

4. Scanner

5. Barcode

6. QR code scanner

7. Digital camera

8. Microphone

Function of keyboard

• Connected to the computer by wireliss connection

• Selection of key all pertorn ditterent task

Other type of keyboard

• magic Keyboard

• digital keyboard

• Qwerty keyboard

How keyboard work

the action will translate to binary and send to CPU to be process.

Function of optical mouse

• use to pointing device s interact with GUI

• Connected to the computer by Bluetooth connection

How optical mouse work

• uses an LED or laser to shine light onto the surface.

• A CMOS sensor captures multiple images per second, and a DSP (Digital Signal Processor) detects movement by analyzing changes in patterns.

• The processed data is sent to the computer, which moves the cursor accordingly.

Name 3 type of touch screen

• Capacitive

• Resistive

• infrated

Describe capacitive

• Made up layer of glass, creating electing fields between glass plates in layers

• when bare figures touch the electric current will change

Advantage of capacitive

• support muti- touch

• better image clarity

Disadvantage of capacitive

More expensive

Describe resistive

• work by calculate amount of downward pressure when applied to the screen.

• based on pressure they detect coordinate where the pressure change happen

Advantage of resistive

Work with input device

Disadvantage of resistive

• No muti - touch

• Low touch sensitivity

Describe infrared

• work by emitting a grid of light across the screen.

• user touches the screen, the finger interrupts the light grid, creating a disturbance

• disturbance translates this into coordinates, activating the correct part of the screen.

Advantage of infrared

Very sensible

Disadvantage of infrared

Low bandwidth

Describe scanner

used to convert image on paper into digital information can be store on computer through OCR (optical character recognition)

Describe 3d scanner

• used to scan 3d object and the scanning will translate into model

Eg CI scanner

Describe 2d scanner

Can read ang type of barcode Eg - read passpont

How barcode work when it scan

• use infra- red light to read the bar

• light reflected back to device and convert into digital

• Eg: LDDLLD

L = 0

D= 1 → Binary equivalent

Represent 12 digit number

1 st - product type

Next 5 number - Manufacturer

Next 5 number - Product code

Last digit - Check digit

How barcode scan

→ Read by red laser

→ Light reflected off white line & black line is not reflect

→ A LED light scan across barcode

How barcode read

→look up in the stock database Key field identifies each stock item

→ The price and stock item sent back to POs

→number of stock item reduce by 1 each time

→ New value no of stock written back to stock item recode

Decribe QR code scanner

• the smallest grild is 21 rows by 21 coulms

• the largest grill is 177 rows by 177 coulombs

• allow character, digit e, internet address

• Used to track information about product in sup by chain

Advantage of QR code

• More secure

• Easy to save

• High storage capacity

Disadvantage of QR code

• difficult to use If people don't have smart phone

• Not secure

Different between barcode and QR code

BARCODE

• Mor than 1 format is available

• Less data

  QR code

• hold much mor information

• More data

Decribe digital camera

Capture photo graph into digital memory

Process by ADC to produce image

Use electronic image sensor to create photograph and record the video

Advantage of digital camera

take image quickly

Image can store permanent on CD or DVD

Disadvantage of digital camera

• difficult to focus

• If the memory card corrup, photo can lost

Decribe microphone

Convert sound wave into electronic signal

works by detecting vibrations in air

Advantage and disadvantage of microphone

Advantage

Easy to give voice

Disadvantage

Take a lot of storage

uses of sensor

• use to measure or read physical properties from surroundings

• use for monitoring system y control system

Monitoring system - track state of system

Control system - control based upon input from sensor

How many sensor type is there?

14

How digital camera work

• capture photograph into digital memory

• use electronic image sensor to create photograph e record video

• process by ADC to produce digital image

Advantage of digital camera

• take image quickly

• image can store permenent on CD or DVD

Use of acoustic sensor

• to moniter noise pollution

• detect change sound level of industrial machinery

- Measure Sound level

Use of accelerometer sensor

-detect orientation of device

- deploy safety feature if need

- measure vibration

Use of flow sensor

-Detect change in flow through pipes in water system

- measure rate of gas & liquild

Use of Gas sensor

Detect level of gas in confined space

- measure carbon monoxide

Use of humidity sensor

• moniter humidity in greenhouse

- measure level of water vapour

Use of infrared sensor

Measure heat radiation of object

Use of level sensor

Detect level of water in water in water tank

measure liquild level

Use of light sensor

Automatic swich on the light when get dark

measure light level

Use of magnetic field

Anti- click braking system

measure presence & strength

Use of moisture

Monitoring moisture in solid

measure level of moisture

Use of pH

Monitor ph level in chemical process

measure alkaline

Use of pressure

Monitoring tyre pressure

measure gas, liquild, physical pressure

Use of proximity

Monitoring positional-object

Measure distance

Use of temperature

maintain tem in swimming pool

- control tem in chemical

- measure in c or k

What is output device

Hardware components receive information fron computer systems

- Enable computer to communicate the result of processed data

Name all output device

Actuator

DLP(Digital light processing projector)

LCD(liquid crystal display projector)

Inject printer

Laser printer

3D printer

LED screen

LCD screen

Speaker

Actuator uses

Convert energy into motion

Eg: Make a robot move

How actuator works

Perform physical task based on instruction from a computer

Why actuator use

In any system that need require movement key

Uses of DLP(Digital light processing projector

• Project image onto a screen

• Eg: Large presentation

How DLP work

By shining light though tiny mirror

Why DLP use

High quality image

Uses LCD (liquid crystal display projector)

• Eg Home cinema

• Excellent balance of quality

How LCD work

by shining light through liquid crystal panels

Different between DLP and LCD

DLP

+ • quiether running than LCD

- not have grey component in image

LCD

+• better color saturation than DLP

- have a limited like

Uses of inkjet printer

Thermal bubble

• tiny resistors create heat

Piezoelectric

• containing special which electric current is applied

How inkjet printer work

• By sparying tiny droplets of ink

Uses of laser printer

Use dry power ink (toner) estatic electricity

Different between inkjet printer and laser printer

INKJET

• chep in price

• produce hard copies

LASER

• Expensive than Inkje

• provide output trough laser

Uses of 3d printer

• create 3 dimensional

• printing material from nozzle

Advantage of 3d printer

Advantage

• Allow more complex design

• Save space & cost

Disadvantage of 3d printers

Selection of plastic and not exhaustive

require cleaning up

Uses LED screen

• allow screen to produce lot of light, with little electricity

• work by adjusting intensity of diodes

• billions color can be formed

Advantage of LED screen

• Light weight

• low energy consuption

Disadvantage of LED screen

• Light pollution

• High power consumption

Uses of speaker

• output gear that connect to computer to produce sound resultant

• translate signal into sound wave by moving cone to vibrate

Advantage of speaker

Every in room can hear

- help blind people because text can convert into sound

Disadvantage of speaker

Can disturb other