Quiz submission record for quiz5-1-2 at Mon Jul 19 13:38:01 2004:

Your Answer for Question 1:
c5 will have a carry in if the 4th bit generated a carry out or if a previous carry out has propagated all the way through.

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 function of the ALUSrc control signal is to choose which input (a second source register or a sign extended immediate) to use as the second input for the ALU.  This 2 to 1 multiplexor is necessary in order to reuse the ALU for both the R type and I type formats.

Your Answer for Question 3:
The X's in the truth table mean don't care.  To write a sum-of-products boolean expression for the truth table, write a product boolean expression for each row in the table in which "o" is true or has a value of "1".

o = not(a) + a*not(c)

Yes the table is complete.  Each X can take on two values and represents two lines of the complete truth table.  In the first row, there are 2 X's which means that the first line represents 4 rows of the complete truth table.  The next two rows both have 1 X which means that they each represent 2 lines ion the complete truth table.  4+2+2 = 8 which is the number of unique combinations for 3 bits of input.


Your unique submission ID is quiz5-1-2-cs61c-cj-1090269481-3280.