Gateforum Test Series: CO & Architecture - Pipelining

Question

Comments

10 clock cycles is the answer as no data forwarding is used

Answer 1

answer should be 10 clock cycles

	1	2	3	4	5	6	7	8	9	10
I1	F	D/OF	EX	WB
I2		F	X	X	D/OF	EX	WB
I3			F	X	X	X	X	D/OF	EX	WB

so 10 cycles are required

Comments

your answer is correct. It should be 10

---

see i have studied it from some video lectures..... but you can also refer Computer Organization, Carl Hamacher

---

Yeah, I have that one..Fine

Answer 2

As no operand forwarding is used and we have data dependency in these instructions

we are using values of R1 in second and third instructions, which are yet to be computed by Instruction 1.

If there were operand forwarding then Instruction decode of instruction 2 can happen when write back of instruction 1 was happening

IF	ID	EX	WB
	IF			ID	EX	WB
		IF					ID	EX	WB