Fetch-Decode-execute cycle

Question 1

What happens when a program is to be run?

Answer 1

It first has to be loaded into main memory and from here it can be accessed by the processor which runs each instructions in turn. When the program is loaded the processor is given the start address of where it is held in the main memory.

Question 2

Describe briefly what fetch-decode-execute cycle does to run a program

Answer 2

Fetch an instruction from the main memory Decode the instruction and execute the instruction.

Question 3

How many instructions does the processor execute at a time?

Answer 3

1 instruction at a time

Question 4

What does the processor contain?

Answer 4

It contains Control Unit (CU) Arithmetic Logic Unit (ALU) and registers