Fetch Execute Cycle

Question 1

What is fetch used for

Answer 1

Gets next instruction that is to be executed from main memory

Question 2

Name the first 3 steps:

Answer 2

1. Content from PC is copied to MAR.
2. Content from MAR is then transferred via address bus to main memory.
3. Instruction is then copied from main memory to MBR via the data bus

Question 3

Name the last 2 parts of the fetch part of the fetch-execute cycle

Answer 3

4. PC increments by one.
5. Content form MBR is copied to the CIR.

Question 4

WHAT HAPPENS IN DECODE PART OF THE CYCLE?

Answer 4

Fetched instruction is decoded.
1. Content of CIR is decoded.
2. And then split into two parts operand and opcode.

Question 5

What happens during execute part of the cycle?

Answer 5

Instruction is carried out.
1. Gets any missing data that is required by the register.
2. The instruction is carried out.
3. Results are stored in main memory or in registers.

Question 6

How do you check for interrupts?

Answer 6

Contents inside the status register checks of there are occurrences of an interrupt.