FDE Cycle

Question 1

FETCH

Answer 1

• store the PC in the MAR
• address transferred to address bus
• control unit sends a signal to control bus
• the contents of the memory location is transferred along the data bus to the MDR
• if its an instruction its placed in the CIR
• increment the PC by one

Question 2

DECODE

Answer 2

• look at the opcode in the CIR from Instruction Set

Question 3

EXECUTE

Answer 3

if it is a request for data, the address is stored on the MAR and the data in the memory location is transferred across the data bus to the MDR.
- carry out the instruction