5.6 BASIC COMPUTER STRUCTURE

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AIM

a. Computer terminology - CPU, ALU, IC and control unit

- Software and hardware - Bit and byte - Memory devices such as RAM, ROM, PROMb. Computer technology in aircraft systems

AIRPLANE COMPUTER

• What computer can do :– To detect fault – To monitor aircraft performance– To help pilot do their work– Aircraft does not overstress through excessive

control– Aircraft can be operate efficiently

DEFINITION

• Electronic device• Accept and process data by carrying out of set

of store instructions in sequence. • Using mathematical and logic operation is

know as PROGRAM.

DIGITAL COMPUTER

INPUT CPU / PROCESSOR OUTPUT

INPUT DEVICE

• Keyboard• Keypad• Pointing Devices• Touch pad• Mouse• Joysticks• Paddle• Microphone

OUTPUT DEVICE

• CRT monitor (cathod ray tube)• LCD monitor (liquid crystal display)• LED monitor (light emiting diode)• Sound Output• Light• Aircraft Control Surface• Printer

HARDWARE

• Physical parts of a computer.• Internal hardware device include motherboards, • Hard drives and graphic card, RAM, etc.• External hardware devices include monitors,

keyboards, mouse, printers, etc.• Internal hardware called components, external

hardware devices called peripherals.

SOFTWARE

• Software cannot be touch• Provides the instructions to hardware or serve

as input to another software.• Can be programs, procedures, algorithms and

its documentation.• Binary number as a language.• Type of software : System software & Application software

CPU/PROCESSORS

• Brain of computer• To process data• Microprocessor is a central processing

unit (CPU) that fits on one microchip.• Fabricated by silicon.• Small zap of high voltage current (static

electricity) can destroy the chip.

COMPUTER

CONTROL

ARITHMETIC

MEMORYINPUT

CENTRAL PROCESSOR UNIT (CPU)

OUTPUT

CONTROL UNIT

• Responsible for overall action of computer to perform correct sequence and at the right time.

• Determine by software.• Will control the timing and electronic

switching throughout the computer by clock (synchronous operation).

ALU – ARITHMATIC LOGIC UNIT

• Perform mathematic and basic logical operations.

• Required power processor to perform variable task of division, multiplication, fixed and floating point arithmetic and employ parallel operation for high speed.

Simple example of ALU

REGISTER

• Temporary storage units within CPU.• Can store data or program information.• Store limit amount of temporary basis.

BUSES• As a medium for transfer data from one part to

other part of computer.• Computer highway use large number of parallel

connected wires.• 3 type of buses which is data bus, address bus

and control bus. - Control bus : medium for communicating - Address bus : carry information - Data Bus : Carry actual data being process

MEMORYINPUT/OUTPUT

UNIT

CONTROL BUS

DATA BUS

CENTRALPROCESSING

UNIT

ADDRESS BUS

I/P

O/P

Control bus : medium for communicating Address bus : carry information Data Bus : Carry actual data being process

BIT AND BYTE

• A bit is a binary digit, the smallest increment of data on a computer

• Bits are usually assembled into a group of eight to form a byte.

• Used for measuring the amount of data that is transferred in a second between two telecommunication points

• 1 byte = 8 bits• 1 kilobyte (K / Kb) = 2^10 bytes = 1,024 bytes• 1 megabyte (M / MB) = 2^20 bytes = 1,048,576 bytes• 1 gigabyte (G / GB) = 2^30 bytes = 1,073,741,824 bytes

MEMORY

• Physical devices used to store information which is instructions and data.

• Using binary digit.• Can store data temporary and permanently.

VOLATILE MEMORY

• Lost data when power off.• Volatile memory requires power to maintain

the stored information.

NON-VOLATILE MEMORY

• Permanent store• Non-volatile computer memory that can retain

the stored information even when not powered.

PERMANENT STORAGE• ROM : Read Only Memory

- Use to store permanent data (FIRMWARE)- Cannot be reprogram or change the data - Eg : PROM( for BIOS), CD-ROM

• EPROM : Erasable Program Read Only Memory- Can erase by expose in strong UV light in 10min - Use by military

• EAROM : Electrical Altered Read Only Memory- Combine non-volatility of ROM with electrically alterable of RAM. Considered non volatile RAM.

• Flash Memories- Eg : Hard Disc, Thumb drive

TEMPERORY STORAGE

• RAM : Random Access Memory– Primary Memory (fast but limited capacity)– takes the form of integrated circuits– Allow data to be read quickly – Used to run programs.– Eg : SRAM, DRAM, DDR RAM etc

MEMORY APPLICATION

POWER ON

BIOS

HD

RAM

LOAD

LOAD OSCPU

Only critical part of OS maintain in RAM

When opening Operating System

When opening Application

RAMCPU HD

Application conserve in RAM,

Saved in HD

MICROPROCESSOR

• central processing part of a computer contained within an IC.

• small, lightweight, and relatively cheap when compared to any CPU

• Use for simple application• Can incorporate all the elements of a total

computing system: I/O, ROM, RAM and CPU

ELEMENTARY MICROCOMPUTER

MICROPROCESSOR(CPU) COMPUTER HIGHWAY

ROM

RAM

OUTPUT

INPUT

INPUT/OUTPUTPORTS

AIRBORNE DIGITAL COMPUTER APPLICATION

REGISTERSSEQUENCING

&ADDRESSING

SENSORS:

VOR/DME - OMEGADOPPLER - COMPASS

ETC

MAGNETIC TAPECASSETTE/CARTRIDGE

PUSH BUTTONCONTROLLER

ALPHANUMERICDEDICATED

MAGNETIC CARD READER

TO CONTROL

FROM CONTROLTO

STORE

FROM CONTROL

AD

Signal convert from analog to digital

COMPUTER INPUT

FMS - FLIGHT MANAGEMENT SYSTEM

DISPLAYSCREEN

1 2 3

4 5 6

7 8 9

0

EXEC

MSG

CLEAR

A B C D E F G

H I J K L M N

O P Q R S T U

V W X Y Z /

PPOS NEXTPHASE PERF

FUEL AIRPORTS

DATA FIX

START

DIR

HDGSEL

ENGOUT

SPECF-PLN

ALPHANUMERICKEYPADFUNCTION

SELECTKEYS

LINESELECT

KEYS

DISPLAYBRIGHTNESS

CONTROL

FMS - FLIGHT MANAGEMENT SYSTEM

• Have 2 FMC (Flight Management Computer) in aircraft for redundancy

• Four main functions of FMS:– Automatic Flight Control– Performance Management– Navigation and Guidance– Status and Warning Displays

• Receive input from sub system computer– Flight Control Computer (FCC).– Thrust Management Computer (TMC).– Digital Air Data Computer (DADC)– Engine Indicating & Crew Alerting System (EICAS).