Correct the order of instruction cycle: A. Read the effective address B. Fetch…

Correct order: Fetch the instruction, Decode the instruction, Read the effective address (if required), Execute the instruction.

• Fetch the instruction: retrieve the instruction from memory into the CPU.

• Decode the instruction: interpret the opcode and determine the addressing mode and what actions are required.

• Read the effective address (if required): compute or fetch operand addresses based on the addressing mode determined during decode.

• Execute the instruction: perform the operation using the operands obtained.

Why this order?

• Fetching must occur first because the CPU cannot decode or execute an instruction it has not retrieved.

• Decoding determines whether an effective address is needed and how to compute it, so computing the effective address comes after decode.

• Execution is last because it uses the fully prepared operands and control signals established by the prior steps.