Quiz submission record for quiz5-1-2 at Mon Jul 19 20:10:04 2004:

Your Answer for Question 1:
c5 = g4 + (p4 . g3) + (p4 . p3 . g2) + (p4 . p3 . p2 . g1) + (p4 . p3 . p2 . p1 . g0) + (p4 . p3 . p2 . p1 . p0 . c0)

Your Answer for Question 2:
The ALUSrc control signal is needed because both the arithmetic-logical (R-type) instruction and memory instruction use the ALU. ALUSrc selects which input to put into the ALU's second input, based on the current instruction. The ALU cannot support two different sources for data without the control signal.

Your Answer for Question 3:
Xs in truth tables represent don't cares, which mean that their value does not matter. In the case of this table, where the x's are in the inputs, the xed out inputs do not matter when determining output. So, for the first line, if a is equal to zero, then regardless of b or c's values, the output will be 1.

not(a) + (a . not(c))

The table is complete. It represents all inputs, although some of them are not shown because of the don't cares.


Your unique submission ID is quiz5-1-2-cs61c-ev-1090293004-2033.