PIPELINING

Question 1

What is pipelining?

Answer 1

• the process of completing the fetch, decode, and execute cycles of three separate instructions simultaneously
• while one instruction is being executed, another can be decoded and another can be fetched

Question 2

How does pipelining work? (example)

Answer 2

• fetch instruction 1
• fetch instruction 2, decode instruction 1
• fetch instruction 3, decode instruction 2, execute instruction 1
• fetch instruction 4, decode instruction 3, execute instruction 2
  etc.

Question 3

Why is pipelining used?

Answer 3

• allows different parts of instructions across multiple stages to be held in different registers at the same time
• this is efficient as it makes use of all the registers and cache