Quiz submission record for quiz6-2-2 at Thu Jul 29 08:19:40 2004:

Your Answer for Question 1:
The EPC (exception program counter) holds the address of the instruction that has caused the exception. The cause register is a state register that has a field that stores the reason for the exception. 
EPC is accessed by swc0 and cause by mtc0

Your Answer for Question 2:
When an exception is not critically dangerous, the machines might not associate the exception with its correct instruction. this feature is called imprecise exceptions

Your Answer for Question 3:
Polling is a way for an io device to communicate with the processor.
the drawback of polling is that it can waste a lot of the processor time because often the processor is much faster than the io devices

Your Answer for Question 4:
Memory mapped io means that each register that controls the terminals for input and output has a special memory location. 

loop:
lui $t0, 0xffff
lw $t1, 0($t0)
andi $t1, $t1, 1
beq $t1, $0, exit
lw $v0, 0($t0)

exit:


Your unique submission ID is quiz6-2-2-cs61c-aq-1091114380-564.