Architecture of the CPU *

Question 1

What are the three stages of the fetch-execute cycle?

Answer 1

Fetch
Decode
Execute

Question 2

What happens at each stage of the fetch execute cycle?

Answer 2

Fetch - fetches next instruction from main memory CPU
Brings instructions back

Decode - inspects instructions and works out what needs to be done

Execute - carries out the instruction

Question 3

List the four common CPU components

Answer 3

ALU (Arithmetic Logic Unit)
CU (Control Unit)
Cache
Registers

Question 4

What is the ALU?

Answer 4

(Arithmetic Logic Unit)
Performs calculations and logical decisions

Question 5

What is the CU?

Answer 5

(Control Unit)
Sends signals to control how data moves around the CPU

Question 6

What is cache?

Answer 6

Provides fast access to frequently used instructions and data

Question 7

What are registers?

Answer 7

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

Question 8

What does Von Neumann architecture consist of?

Answer 8

CU, ALU, memory unit (usually RAM), inputs and outputs

Question 9

What does the register Program Counter (PC) do?

Answer 9

it holds the address of the next instruction in memory

Question 10

What does the Memory Address Register (MAR) do?

Answer 10

it holds the address of where data is to be fetched or stored

Question 11

What does the Memory Data Register (MDR) do?

Answer 11

it holds the data fetched from, or to be written to memory

Question 12

What does the accumulator do?

Answer 12

it holds the results of calculations