Quiz submission record for quiz5-2-2 at Thu Jul 22 09:32:00 2004:

Your Answer for Question 1:
The branch delay slot is used in delayed branching.  This method always executes the next sequential instruction, with the branch taking place after that one instruction. The slot is used for storing the next instruction. Branch delay is used to control hazards.

Your Answer for Question 2:
There is a stall due to a data hazard.  Since t0 is used in lw, delayed branching makes the instruction wait until t0 has been written in the fifth stage in order to have access to it in the add instruction.  Schemes used to reduce this delay are callled forwarding or bypassing.  The idea is that right after the load has taken place, we can suppply it as an input for subtract, thereby getting the item early from theinternal resources.

Your Answer for Question 3:
Since pipelining uses a delay where it is stored in a slot, by reducing the transistor count, this branch delay will no longer work.  The idea for pipelining is that it increases the number of simultaneously executing instructions , but it still takes the same amount of time for an individual instruction.  So the data memory is essential for the pipelining scheme.


Your unique submission ID is quiz5-2-2-cs61c-av-1090513920-981.