Quiz submission record for quiz6-2-2 at Thu Jul 29 06:15:59 2004:

Your Answer for Question 1:
the EPC holds the address of the affected instruction
the cause register it used to record the cause of the exception

mfc0 $k1 $14 uses EPC and mov $a0 $k0 uses cause


Your Answer for Question 2:
imprecise exceptions are caused when pipelined computers don't record the correct instruction that the exception occured at.

Your Answer for Question 3:
polling an I/O device causes lots of overhead and is generally much slower than the memory

Your Answer for Question 4:
memory-mapped io means that portions of teh address space in memory are assigned to i/o devices.

li $t0, 0xffff0000
li $t1, 0xffff0004
li $t2, 0xffff0008
li $t3, 0xffff000c

L1: lw $t7, 0($t1)
    lw $t4, 0($t2)
    and $t5, $t4, 1
L2: bne $0, $t5, exit
    j L1
exit: sw $t7, 0($t3)
      j L1


Your unique submission ID is quiz6-2-2-cs61c-ao-1091106959-2583.