Quiz submission record for quiz6-1-1 at Sun Jul 25 18:20:51 2004:

Your Answer for Question 1:
without a pipelined control, certain events would be off in timing.
A call to a register that was written on the line before (or two,three,four lines) would use the old value of that register, possibly rendering the first line useless.

A branch could occur, then the lines that should not have run would still run if they had already been queued into the pipeline.

If by pipelined control included the pipeline registers, then nothing would ever happen because values would continually be overwritten before they propagated down he datapath.

Your Answer for Question 2:
1.  The original register value
add $2, $3, $4
2.  The updated value from the previous line
add $2, $3, $4
sub $3, $2, $4
3.  The value which was just loaded in from memory
lw  $2, 0($sp)
add $2, $2, $2

Your Answer for Question 3:
The hazard unit inserts a bubble by keeping the PC and the instruction fetch -> instruction decode pipeline registers from changing.
It also sends a noop instruction to the instruction decoder.

Since a bubble was inserted into the instruction decode register, a second test for a load will return false and the pipeline will continue.




Your unique submission ID is quiz6-1-1-cs61c-am-1090804851-520.