Quiz submission record for quiz6-2-2 at Thu Jul 29 10:02:44 2004:

Your Answer for Question 1:
it used to hold teh address of the affected instruction. The cause register used to hold the cause of the exception. EPC is for la and branch instructions, and J type instructions, which are related to the address. Cause is for R-type instructions and some I-type instructions, such as add, sub, addi.

Your Answer for Question 2:
The difficulty of always associating teh correct exception with the correct instructions in pipelined computers.

Your Answer for Question 3:
The process of periodically checking status bits to see if it is time for teh next I/O operation is called polling. It can waste a lot of processor time because processors are so much faster than I/O devices.

Your Answer for Question 4:
contain addresses are not regular memory. Instead, they correspond to register in I/O device.
     la $s0, receiver
loop: lb $t0, 0($s0)
      addi $s0, $s0, 1
      beqz $t0, receive
      j loop
receive: mov $v0, $t0
         jr $ra


Your unique submission ID is quiz6-2-2-cs61c-cq-1091120564-3234.