Quiz submission record for quiz6-1-1 at Mon Jul 26 08:44:47 2004:

Your Answer for Question 1:
The result would be that you would be writing to registers that you didn't intend to write to and you would be storing incorrect data into memory.  You might add a sign extended 16-bit number when you wanted to add from a register.  You might be branching when you wanted to just execute an add instruction.

Your Answer for Question 2:
Feeding data from register file or ID/EX pipeline register:
  add $1, $2, $3
  sub $4, $5, $6

Feeding data from EX/MEM pipeline register:
  sub $2, $1, $3
  and $12, $2, $5

Feeding data from MEM/WB pipeline register:
  sub $2, $1, $3
  add $3, $6, $7
  or $13, $6, $2

Your Answer for Question 3:
The hazard unit inserts bubbles by preventing the PC register and the IF/ID register from changing.  In addition, to stall the pipeline, we need to deassert all the control signals in the EX MEM and WB stages.  These control values are then percolated forward so that nothing is done during the clock cycle.
Fetching the next instruction prevents the hazard unit from inserting the same bubble over and over.


Your unique submission ID is quiz6-1-1-cs61c-ee-1090856687-1847.