1.1 System Architecture

Question 1

What is a computer?

Answer 1

An electronic device which takes input, processes data , and delivers output

Question 2

What is the CPU?

Answer 2

Executes instructions and performs calculations

Question 3

What is memory?

Answer 3

Stored in programs

Question 3

What is the FDE cycle?

Answer 3

In which a computer fetches institutions, decodes them, and executes them in a continuous repetitive cycle billions of times in a second

Question 4

What is the role of Fetch in the FDE cycle?

Answer 4

when the CPU fetches the instructions from the main memory and stores it into the processor

Question 5

What is the role of Decode in the FDE cycle?

Answer 5

The instruction needs to be decoded before it can run. The control signal works out what signals to issue to the component for execution.

Question 6

What is Execute?

Answer 6

The instruction is carried out(the control unit sends signals to relevant components)

Question 7

What is the clock speed?

Answer 7

Measured in Hertz - one cycle per second

Question 8

What is the CPU made up of?

Answer 8

Arithmetic Logic Unit, Control Unit, Cache and Registers

Question 9

What is the Arithmetic Logic Unit (ALU)?

Answer 9

This is responsible for carrying out arithmetic calculations and making logical decisions

Question 10

What is the Control Unit?

Answer 10

The control unit sends signals to control how data moves around CPU and co-ordinates the CPU’s operations

Question 11

What is the Cache?

Answer 11

A small amount of very fast memory, is located in the CPU. It provides fast access to frequently used instructions and data.

Question 12

What is the Register?

Answer 12

Tiny super-fast pieces of onboard memory inside the CPU, each with a very specific purpose.

Question 13

What is the Von Neumann Architecture?

Answer 13

It is based on the stored-program computer concept, where instruction data and program data are stored in the same memory in binary form.

Question 14

What does VNA consist of?

Answer 14

CPU, CU, ALU, Memory Unit (RAM) and Inputs and Outputs

Question 15

What are programs made up of?

Answer 15

A sequence of instructions, stored in the main memory outside of the CPU. They are fetched, one by one, to the registers for processing.

Question 16

Examples of special purpose registers

Answer 16

Accumulator, Memory Address Register, Program Counter and Memory Data Register

Question 17

What is the Program Counter?

Answer 17

Holds the address of the next instructions to be executed in memory

Question 18

What is the Memory Address Register?

Answer 18

Holds the address of the current instructions (of where data is to be fetched or stored) to be executed

Question 19

What is the Memory Data Register?

Answer 19

Holds the data fetched from, or to be written to memory.

Question 20

What is the Accumulator?

Answer 20

Holds the results of calculations.

Question 21

What are the Characteristics of the CPU?

Answer 21

Clock Speed, Cache size, Number of Cores

Question 22

What is the Clock Speed?

Answer 22

Refers to the number of instructions a CPU can execute per second. It is measured in hertz (Hz) or gigahertz (GHz). Higher clock speeds generally result in faster processing

Question 23

What is Cache size?

Answer 23

A temporary storage of instructions and data which are being read from and written to the main memory. It stores copies of recent data and instructions, allowing the CPU to retrieve them quickly from the cache than from the main memory (RAM)

Question 24

What is Number of Cores?

Answer 24

Core - a complete copy of CPU e.g. Quad-core processor would have 4 separate processing units - Registers, ALU, Accumulator, CU, etc. The number of cores impacts processor performance by enabling the CPU to perform multiple instructions at the same time.

Question 25

Does doubling number of cores increase overall speed?

Answer 25

No. CPU cores have to communicate with each other which takes time. Many programs are not designed to make use of multiple cores

Question 26

What is an embedded system?

Answer 26

A computer system with a dedicated function within a larger mechanical and electrical system`

Question 27

Examples of properties of embedded computers compared to general purpose computer:

Answer 27

Low power consumption, small size, rugged operating systems, low cost per unit

Question 28

Give examples of embedded systems

Answer 28

These include traffic lights, smartwatches, home security systems