CPUs and architecture
What is the correct basic order in which a CPU processes an instruction?
- AExecute → decode → fetch
- BFetch → decode → execute
- CDecode → fetch → execute
Show answer and explanation
Answer: B. Fetch → decode → execute
The CPU fetches an instruction from memory, decodes it to determine what to do, and executes the operation. Where needed, it writes the result back to a register or memory. Pipelining overlaps these stages so they proceed in parallel.
- A. An instruction cannot be executed before it is fetched.
- B. Correct. Fetch, decode, then execute.
- C. An instruction cannot be decoded before it is fetched.