Question

What are the pipelining stages include?

(a) Fetch, Decode, Write

(b) Fetch, Decode, Execute

(c) Fetch, Execute, Write

(d) Fetch, Decode, Execute, Write

This question was addressed to me in an online quiz.

Question is taken from Microcontroller (ARM 7- Pipelining) in portion Prototyping Embedded Devices of IOT

Answer 1

The correct answer is (a) Fetch, Decode, Write

For explanation: ARM7 core has 3-stage pipeline that increases instruction flow through processor up to three times. So each instruction is executed in 3 stages:

Fetch – instruction is fetched from memory and placed in pipeline

Decode – instruction is fetched and data-path signals prepared for next cycle

Execute – instruction from prepared data-path reads from registry bank, shifts operand to ALU and writes generated result to dominant register.