Quiz submission record for quiz6-2-2 at Wed Jul 28 18:37:40 2004:

Your Answer for Question 1:
There are 2 types of exceptions that we consider here: an undefined instruction and an arithmetic overflow.  EPC register holds the address of the offending instruction when the machine performs an action to deal with exception occurance.

The Cause Register holds a field that indicates the reason for the exception.

MIPS instructions that access EPC and Cause are lw, sw, j, beq. 

Your Answer for Question 2:
We know that the difficulty of always associating the correct exception with the correct instruction has led some computer designers to relax this requirement in noncritical cases.  Such machines are said to have imprecise interrupts or imprecise exceptions.

Your Answer for Question 3:
The disadvantage of polling is that it can waste a lot of processor time because processors are so much faster than I/O devices.

Your Answer for Question 4:
One of the two methods used to address the device is "memory-mapped io".  In memory-mapped I/O, portions of the address space are assigned to I/O devices.  Read and writes to those addresses are interpreted as commands to the I/O device.


I don't really understand how to poll the receiver.


Your unique submission ID is quiz6-2-2-cs61c-cb-1091065060-836.