Pipeline

Question

@Arjun sir

In the Question :-  https://gateoverflow.in/1391/gate2005-68

I have drawn like :- 

F  D  E  M  W

    F   D  D   E  M  W

          F  -    D   E  M  W            Total 8 Clock cycle with operand forwarding.

Why cant we Overlap stuffs means:- 

In first case at second instruction the data will be available only after the memory access of first instruction.We could do something like in the Upper edge of the clock fetch from the memory and in the downward edge of clock Do the execution operation of next stage. If we follow this policy we will get 7 clock cycles.

Checkout the comment of Arjun Sir:-  https://gateoverflow.in/3623/gate2006-it-79

Or when to use such technique as depicted by Arjun Sir.

Answer 1

 

serial no.	cycle 1	cycle 2	cycle 3	cycle 4	cycle 5	cycle 6	cycle 7	cycle 8	cycle 9
I1	IF	RD	EX	MA	WB
I2		IF	---------	RD	EX	MA	WB
I3			IF	--------	RD	EX	MA	WB

USING THE DATA FORWARDING