1.1 Sytems Architecture

Question 1

What is a general purpose computer ?

Answer 1

a computer that is designed to be able to carry out many different tasks.

Question 2

What is an application ?

Answer 2

A software program that allows a user to perform a specific task.

Question 3

What is hardware ?

Answer 3

the physical components of the computer

Question 4

What is software ?

Answer 4

the programs that run on a computer

Question 5

What is the purpose of the CPU ?

Answer 5

• process data and instructions
• control the rest of the computer system

Question 6

What is the first step of the fetch - decode- execute cycle ?

Answer 6

memory address held in the PC is copied into the MAR.

Question 7

What is the second step of the fetch - decode- execute cycle ?

Answer 7

address in the PC is then incremented
by one.

Question 8

What is the third step of the fetch - decode- execute cycle ?

Answer 8

processor sends a signal along the address bus to the memory address held in the MAR.

Question 9

What is the fourth step of the fetch - decode- execute cycle ?

Answer 9

instruction/data held in that memory address is sent along the data bus to the MDR.

Question 10

What is the fifth step of the fetch - decode- execute cycle ?

Answer 10

The instruction/data held in the MDR is copied into the CIR.

Question 11

What is the sixth step of the fetch - decode- execute cycle ?

Answer 11

The instruction/data held in the CIR is decoded and then executed.
Results of processing are stored in the ACC.

Question 12

What is the seventh step of the fetch - decode- execute cycle ?

Answer 12

The cycle returns to step one

Question 13

What are the six main components of the CPU ?

Answer 13

control unit (CU)
arithmetic logic unit (ALU)
registers
cache
buses
clock

Question 14

What is the Control Unit ?

Answer 14

The component of the CPU that manages instructions.

Question 15

What is the ALU ?

Answer 15

performs arithmetic and logic calculations.

Question 16

What is a register ?

Answer 16

high speed memory that stores data to be processed.

Question 17

What is a bus ?

Answer 17

A channel of communication used to transport data and instructions in the CPU

Question 18

What is a clock ?

Answer 18

sends out regular pulse to synchronise the computer’s hardware components.

Question 19

What are the three main functions of the Control Unit ?

Answer 19

• fetch ,decode, execute instructions
• issues control signals that control hardware
• moves data around the system

Question 20

What are the two main functions of the ALU ?

Answer 20

• performs arithmetic and logical operations
• gateway between primary memory and secondary storage

Question 21

What is the purpose of the cache ?

Answer 21

used to temporarily hold data and instructions that the processor is likely to reuse

Question 22

What are the two types of cache ?

Answer 22

L1, L2

Question 23

What are the properties of L1 cache ?

Answer 23

• extremely fast transfer rates
• very small in size.

Question 24

What does L1 cache hold ?

Answer 24

most frequently used instructions and data.

Question 25

What are the properties of L2 cache ?

Answer 25

- Bigger in capacity than L1 - Slower in speed

Question 26

What does L2 cache hold ?

Answer 26

data and instructions that are needed less frequently.

Question 27

What is Von Neumann architecture ?

Answer 27

A stored program concept

Question 28

What are the key elements of Von Neumann architecture ?

Answer 28

- D and I stored in binary digits - D and I stored in primary memory - Instructions are fetched serially - the processor decodes and executes an instruction, before cycling around -The cycle runs till there is no more variables

Question 29

What is the purpose of the MAR ?

Answer 29

- holds the address of the current instruction that is to be fetched from memory - or the address in memory to which data is to be transferred

Question 30

What is the purpose of the MDR ?

Answer 30

- holds the contents found at the address held in the MAR - or data which is to be transferred to primary memory

Question 31

What is the purpose of the CIR ?

Answer 31

holds the instruction that is currently being decoded and executed

Question 32

What is the purpose of the ACC (Accumulator)?

Answer 32

holds the data being processed and the results of processing

Question 33

What is clock speed ?

Answer 33

The frequency of the pulses

Question 34

What are the three factors that affect CPU performance ?

Answer 34

- clock speed - cache size - number of cores

Question 35

How is clock speed measured ?

Answer 35

Hertz - Hz

Question 36

What are the effects of overclocking ?

Answer 36

long term damage to the CPU as it is working harder and producing more heat.

Question 37

What is the Program Counter ?

Answer 37

holds the memory address of the next instruction to be fetched from primary memory

Question 38

What is an embedded system ?

Answer 38

A special purpose computer built into another device.

Question 39

What are the advantages of embedded systems over general purpose computers ?

Answer 39

- limited functions = cheaper to design +build - Require less power - Don't need much processing power

Question 40

Do embedded systems require frequent updates ?

Answer 40

YES