1.1 System Architecture

Question 1

What’s the purpose of the CPU

Answer 1

TO manage basic operations of the computer, “the brain”

Question 2

4 elements to form a basic computer system

Answer 2

1.INput
2. CPU
3.Output
$.Secondary Storage

Question 3

2 main components of the CPU?

Answer 3

ALU and CU

Question 4

Most common form of computer architecture

Answer 4

Von Neumann Architecture

Question 5

What cycle does the CPU continuously do to process instructions

Answer 5

FDE cycle

Question 6

What is data stored in a computer on?

Answer 6

Binary

Question 7

Role of the register in the CPU

Answer 7

Hold on to temporary data and instructions being held by the CPU

Question 8

What is the name of the register which keeps the address of the next instruction to be processed

Answer 8

PC - Programme Counter

Question 9

Which register is used to store data that is fetched from main memory?

Answer 9

The memory data register (MDR)

Question 10

Which register is used to tell the CPU where to locate this data?

Answer 10

The memory address register (MAR)

Question 11

What is the name of the register that temporarily stores the results of logic operations and calculations during processing?

Answer 11

The accumulator (ACC)

Question 12

What unit of measurement is used to describe the clock speed of a processor?

Answer 12

Hertz/Gigahertz

Question 13

Suppose a CPU is capable of performing 1 billion operations per second. What is the clock speed of CPU?

Answer 13

1 GHz

Question 14

Why does increasing the cache size increase the performance of the processor?

Answer 14

The CPU has more immediate access to data, instead of having to fetch the data from RAM, which is slower.

Question 15

State one drawback of cache memory in comparison with main memory.

Answer 15

Cache memory is much more expensive than main memory.

Question 16

Typically, around how large is the cache memory located closest to the CPU?

Answer 16

Anywhere between 2 and 64 kB

Question 17

Does doubling the number of cores exactly double the performance of a processor?

Answer 17

No

Question 18

What is meant by an ‘embedded’ system?

Answer 18

A computer system which forms part of an electronic device

Question 19

Give an example of an embedded system that could be found in the human body.

Answer 19

Pacemaker

Question 20

Give three examples of devices that you can find in your house that may contain an embedded system.

Answer 20

1. Fridges 2. Microwaves 3. Digital clocks

Question 21

Cars are an example of an object with multiple embedded systems for performing different tasks. Suggest two uses for an embedded system in a car.

Answer 21

1. Air conditioning 2. Parking sensors

Question 22

Suggest two reasons why a manufacturer may use embedded systems instead of general purpose computers in their products.

Answer 22

1. They are cheaper 2. They can be smaller

Question 23

How do embedded systems and general-purpose computers differ?

Answer 23

Embedded systems generally perform a single simple task, and don’t have operating systems. General-purpose computer systems can perform multiple tasks and have an operating system.

Question 24

State two functions of the control unit.

Answer 24

1. Sending signals to control the flow of data and instructions 2. Decoding instructions

Question 25

What is ‘cache memory’? Why is it useful during program execution?

Answer 25

A small section of extremely fast memory used to store commonly used instructions and data. It is useful as the CPU has direct access to the cache.

Question 26

Order the three levels of cache in order of proximity to the processor (1 = closest, 3 = furthest).

Answer 26

1. L1 cache 2. L2 cache 3. L3 cache

Question 27

Explain the function of the ALU and give some examples of the operations that it carries out.

Answer 27

The ALU carries out mathematical operations / logical operations / shifting operations on data; examples include multiplication, division, logical comparisons.

Question 28

What is meant by an ‘address’ in the context of a CPU?

Answer 28

A location in the main memory which stores data or instructions

Question 29

Which bus is used to carry memory addresses from the CPU to main memory?

Answer 29

The address bus

Question 30

Describe the first process that occurs in the fetch and execute cycle.

Answer 30

(Instructions to be executed are / Data is) fetched from memory.

Question 31

Suppose data is fetched from main memory. Which register does it get stored in?

Answer 31

The memory data register (MDR)

Question 32

Suppose an instruction is fetched from main memory. Which register is does it get stored in?

Answer 32

The current instruction register (CIR)

Question 33

Which register is used to keep track of which memory location to look at for the next instruction?

Answer 33

The program counter (PC)

Question 34

Which part of the CPU is used to translate instructions into a set of operations that can be performed directly by the CPU?

Answer 34

The control unit