System Architecture

Question 1

What is the purpose of the cpu

Answer 1

Fetch decode and execute instructions

Question 2

What does cpu stand for

Answer 2

Central processing unit

Question 3

Von Neumann architecture

Answer 3

1.Data and instructions stored in the primary storage
2.Instructions are fetched from memory one at a time in order
3.the processor decor and executes and instruction before cycling round to get new instruction this repeats till no more instruction available

Question 4

What does pc stand for

Answer 4

Program counter

Question 5

What does the pc do

Answer 5

Holds the memory adress of the next instruction to be executed

Question 6

What does Mar stand for

Answer 6

Memory adress register

Question 7

What does the mar do

Answer 7

Holds the memory adress of where data is about to be fetched from or stored into

Question 8

What does mdr stand for

Answer 8

Memory data register

Question 9

What does the mdr do

Answer 9

Holds data that has been fetched from ram

Question 10

What does the accumulator do

Answer 10

Holds result of calculations from alu

Question 11

What does alu stand for

Answer 11

Arithmetic logic unit

Question 12

What does the alu do

Answer 12

Performs calculations

Question 13

What does cu stand for

Answer 13

Control unit

Question 14

What does the cu do

Answer 14

Decodes instructions

Question 15

What does the cache do

Answer 15

Allows for very quick access to frequently used data and instructions
By holding memory in or close to the processor

Question 16

What happens during a fetch decode and execute cycle

Answer 16

fetch : address of next instruction to be processed copied from PC to the MAR
Pc is incremented to point next instruction when cycle restart . The instruction held by the MAR copied to MDR
2.DECODE - the CU decode the instructions and sends signals to around CPU to fetch or write
3.EXECUTE -the operation performed for example the ALU might add operations given the control unit