Which phase of the fetch-decode-execute cycle might use a circuit in the arithmetic-logic unit?
A) fetch
B) decode
C) execute
D) during fetch or execute, but not decode
E) any of the phases

Question

Quizplus · Accepted Answer

The arithmetic-logic unit (ALU) is responsible for performing arithmetic and logical operations on data, which occurs during the execute phase of the fetch-decode-execute cycle. Therefore, choice C, execute, is the best answer. The fetch and decode phases are focused on fetching the instruction and decoding it, respectively, and do not involve the ALU. During fetch or execute, but not decode is also incorrect because the ALU is not used during fetch. Finally, while it is possible for the ALU to be used during any phase in theory, it is most commonly used during the execute phase.

Which Phase of the Fetch-Decode-Execute Cycle Might Use a Circuit