Notes from Class Book

Question 1

Why is FDE cycle used

Answer 1

Cycle carried out to process data

Question 2

What happens in the Fetch stage and what registers are involved

Answer 2

Fetches data from RAM and stores it in registers

PC, MAR, MDR

Question 3

What happens in the Decode stage and what registers are involved

Answer 3

CPU Decodes and gets ready for next step

CIR

Question 4

What happens in the Execute stage and what registers are involved

Answer 4

Instruction is carried out

ALU, ACC

Question 5

What makes up the CPU

Answer 5

ALU, CU and Registers

Question 6

What is clock speed

Answer 6

Instructions carried out per second. It can be increased, overclocking

Question 7

What is pipelining

Answer 7

Where the output of one stage is the input of the next

Question 8

Why is pipelining used

Answer 8

To speed up tasks

Question 9

What is instruction pipelining

Answer 9

As one instruction is executed the next can be decoded and the next fetched, queueing them up and decreasing processing time.

Question 10

What is are the limitations of pipelining

Answer 10

If it fails and fetches the wrong instruction them whole pipeline must be flushed

Question 11

What are the 5 registers (in order of use)

Answer 11

PC
MAR
MDR
CIR
ALU
ACC

Question 12

What does the PC do

Answer 12

Points to the address of the next instruction to be executed

Question 13

What does the MAR do

Answer 13

Holds address of instruction in memory

Question 14

What happens after MAR is used in FDE cycle

Answer 14

Address travels to RAM and data is returned by data bus

Question 15

What does the MDR do

Answer 15

Stores data after it has been fetched from RAM

Question 16

What happens after MDR is used FDE cycle

Answer 16

CU decodes instruction

Question 17

What does the CIR do

Answer 17

Stores decoded instruction

Question 18

What does ALU do

Answer 18

Performs arithmetic or logic calculations

Question 19

What does ACC do

Answer 19

Stores result of calculations in ALU

Question 20

What are buses and what are the 3 types

Answer 20

Metal tracks on the motherboard
- Address
- Data
- Control

Question 21

What is a register

Answer 21

Small, temporary, super fast memory

Question 22

What happens when you open a program

Answer 22

Data and instructions are loaded into RAM

Question 23

What does the CU do

Answer 23

Decodes instructions, controls flow of data

Question 24

What is a feature of both the data and control bus

Answer 24

2 directional (CPU <-> Memory)

Question 25

What does the control bus do

Answer 25

Responsible for communicating control signals

Question 26

What is a feature of the address bus

Answer 26

One directional (CPU --> Memory)

Question 27

What affects performance of CPU

Answer 27

- Clock Speed (Hz) - Cores - Cache Size - Heat - Width of address bus - Parallel Processing

Question 28

What is clock speed determined by

Answer 28

Vibrations of a quartz crystal

Question 29

What is the speed of the FDE cycle determined by

Answer 29

CPUs clock chip

Question 30

Name the 4 types of primary storage

Answer 30

Cache, RAM, ROM, registers

Question 31

Name 2 types of secondary storage

Answer 31

Hard disk, Flash drive

Question 32

How does width of address bus affect performance of CPU

Answer 32

If the width is larger then more memory locations can be addressed

Question 33

What is the Operand

Answer 33

The data itself

Question 34

What is a drawback of parallel/concurrent processing

Answer 34

Some instructions are not compatible with parallel processing

Question 35

What is the stored program concept

Answer 35

Program must be loaded into main memory to be executed by the processor - instructions are fetched one at a time

Question 36

What is Von Neumann Architecture and name a limitation

Answer 36

Shared memory for programs + data instructions + data, both share a bus. Limitation - Bottlenecking

Question 37

What is bottlenecking

Answer 37

Component that limits the potential of other hardware due to the differences in maximum capabilities of the 2 components

Question 38

What is Harvard Architecture and name a limitation

Answer 38

Separate memories with separate buses. Programs and data don't have to compete for same bus Limitation - Cost (very expensive)

Question 39

When would Harvard be used over Von Neumann

Answer 39

When speed is more important than cost, if the system is a risk to life, normally in specialist embedded systems

Question 40

Advantages of Von Neumann

Answer 40

Simplifies design of control unit Cheaper Data from memory and devices accessed in same way

Question 41

Can processors use both architectures

Answer 41

Yes, In desktop computers Cache uses Harvard and RAM uses Von Neumann

Question 42

What is CISC

Answer 42

Complex Instruction Set Computer

Question 43

What is RISC

Answer 43

Reduced Instruction Set Computer

Question 44

Features of CISC

Answer 44

- Quicker to code programs - Compiler has little work to do to translate high level language to machine code - As code is short, less RAM needed to store instructions

Question 45

Features of RISC

Answer 45

- Instruction set made up of a small number of fixed length instructions - Hardware is simpler to build with fewer circuits needed for carrying out complex instructions - Each instruction takes same amount of time so pipelining is possible - RAM is now cheap so RISCs use of RAM and software allows better performance processors at less cost

Question 46

What is a GPU

Answer 46

Graphics Processing Unit, uses 1000s of small efficient cores. Used to accelerate scientific, engineering and other applications

Question 47

What is a Co-Processor

Answer 47

Uses an extra, more powerful core

Question 48

Name 3 Manual Input devices

Answer 48

Keyboard Microphone Sensors

Question 49

Name 3 Output devices

Answer 49

Printer Projector Speakers

Question 50

Name 3 types of Sensor

Answer 50

Infrared Light Pressure

Question 51

What are the 2 types of barcodes

Answer 51

- UPC-A Retail and Warehousing (digits only) - Code 128 Transport and Shipment Tracking (Letters and numbers)

Question 52

What is a Sensor

Answer 52

Hardware device that can take measurement of physical properties

Question 53

What is Monitoring

Answer 53

Report Values

Question 54

What is Control

Answer 54

Can change value of next input. The output can alter how the process operates

Question 55

Name 4 types of Printer

Answer 55

- Inkjet - Laser - Dot Matrix - 3D

Question 56

What does an Inkjet printer do

Answer 56

Most common printer. Printer is cheap, the ink is marked up.

Question 57

What does a Laser printer do

Answer 57

Uses dry powdered ink called toner. Businesses use them almost exclusively. Fast, reliable, excellent quality.

Question 58

What does a dot matrix printer do

Answer 58

Impact printer, similar to a typewriter. Noisy, Expensive, poor quality. Useful in damp environment.

Question 59

What is an RFID

Answer 59

Radio Frequency ID card. Use a transponder and reciever.

Question 60

What is an Actuator

Answer 60

Motors commonly used in conjunction with sensors to control a mechanism.