Fetch Decode Execute Cycle

Question 1

Fetch 1

Answer 1

Next instruction is copied from the PC to the MAR

Question 2

Fetch 2

Answer 2

Instruction held at the address is copied to the MDR

Question 3

Fetch 3

Answer 3

PC is incremented

Question 4

Fetch 4

Answer 4

Contents of the MDR is copied to the CIR

Question 5

Decode

Answer 5

Contents of the CIR is decoded. Instruction is split into opcode and operand

Question 6

Execute

Answer 6

Opcode is carried out on operand, location of operand saved in MDR