Question

1. (20 pts each) Read the following set of instructions, and answer questions.

or r1, r2, r3

or r2, r1, r4

or r1, r1, r2

Assume the following cycle times for each of the options related to forwarding:

Without forwarding	With full forwarding	With only ALU-ALU forwarding
250ps	300ps	290ps

ALU-ALU forward means there is only data forward from EX/MEM to ID/EX (which is from the output of the ALU to the input of the ALU), and no data forwarding from MEM/WB to ID/EX.

1. Assume not forwarding, identify all data hazards similar to the requirement in question 1- Draw multiple-cycle diagram to demonstrate pipeline execution. How much time is consumed to finish these three instructions?

2. Repeat above question assuming full forwarding.

3. Repeat above question assuming there is only ALU-ALU forwarding.

Answer 1