1.1 Systems Architecture

Question 1

Hardware

Answer 1

Physical components that make up a computer

Question 2

Software

Answer 2

Programs or applications that a computer runs

Question 3

What do computers do?

Answer 3

Input
Process (done by CPU)
Stores
Outputs data

Question 4

CPU full form

Answer 4

Central Processing Unit

Question 5

CPU

Answer 5

The brain of a computer system
Processes data + instructions to make the system work
-> its processing power depends on other components

Question 6

Main components of the CPU

Answer 6

CU
ALU
Cache

Question 7

CU

Answer 7

Control Unit
Fetches, decodes and executes program instructions (by following the fetch-execute cycle)

Controls the flow of data in the CPU

Question 8

ALU

Answer 8

Arithmetic Logic Unit
Performs all calculations: addition, subtraction, multiplication, division
Performs logic operations: AND, OR, NOT, binary shifts

Question 9

How does the ALU do multiplication and division?

Answer 9

Repeated addition and subtraction

Question 10

What does the ALU contain?

Answer 10

The accumulator

Question 11

Cache

Answer 11

Data storage in the CU
Stores regularly used data so that the CPU can access it quickly when needed for operations

Question 12

How does the CPU check for data?

Answer 12

It checks the Cache first, then the RAM

Question 13

Disadvantage of Cache

Answer 13

Low capacity and expensive

Question 14

Different levels of cache

Answer 14

L1 - quickest, lowest capacity
L2 - slower, higher capacity
L3 - slower, higher capacity
L4 - slower, higher capacity

The levels increase in size, and decrease in speed

Question 15

Von Neumann Architecture

Answer 15

Describes a system where the CPU runs programs stored in memory

Question 16

What is a program?

Answer 16

Consists of data + instructions

Question 17

What does the CU contain?

Answer 17

Program Counter

Question 18

What does the ALU contain?

Answer 18

Accumulator

Question 19

What are the registers

Answer 19

MAR
MDR

Question 20

Program Counter

Answer 20

Holds the memory address of the instruction for each cycle

Question 21

MAR full form

Answer 21

Memory Address Register

Question 22

MDR full form

Answer 22

Memory Data Register

Question 23

MAR

Answer 23

Holds any memory address of an instruction or data, about to be used by the CPU

Question 24

MDR

Answer 24

Holds the actual instructions or data

Question 25

Memory

Answer 25

Holds program instructions or program data

Question 26

Accumulator

Answer 26

Stores intermediate results of calculations in the ALU

Question 27

Fetch - Execute Cycle

Answer 27

The process that the CPU uses to retrieve and execute instructions

Question 28

FETCH in Fetch - Execute Cycle

Answer 28

1. Copy memory address from program counter to MAR 2. Copy instruction stored in MAR address to the MDR 3. Increment program counter, ready for next cycle

Question 29

DECODE in Fetch - Execute Cycle

Answer 29

4. Instruction in MDR is decoded by the CU

Question 30

EXECUTE in Fetch - Execute Cycle

Answer 30

5. The instruction is performed

Question 31

Factors that affect CPU performance

Answer 31

Clock Speed Cache Size Number of Cores RAM Size GPU

Question 32

Clock Speed

Answer 32

The number of instructions that a single process can carry out per second (Hz)

Question 33

Number of Cores

Answer 33

Each core works independently from eachother

Question 34

GPU full form

Answer 34

Graphics Processing Unit

Question 35

GPU

Answer 35

Specialised circuits for handling graphics + image processing

Question 36

How Clock Speed affects CPU performance

Answer 36

Higher clock speed = more instructions carried out per second

Question 37

How the Number of Cores affects CPU performance

Answer 37

More cores = more instructions carried out at once

Question 38

How RAM Size affects CPU performance

Answer 38

More RAM = more applications can smoothly run

Question 39

How GPU affects CPU performance

Answer 39

GPU = improved performance of graphic intensive applications (e.g. P.C. gaming)

Question 40

Advantages of Embedded Systems

Answer 40

Easy to deign Cheap More efficient at doing the designated task compared to a general purpose computer

Question 41

Embedded Systems

Answer 41

Computers inside a larger system/other device

Question 42

What are Embedded Systems dedicated to?

Answer 42

A single task

Question 43

Example of an Embedded System

Answer 43

Washing Machine Microwave Oven