Assignment 8, due Oct 21

On every assignment, write your name legibly as it appears on your University ID card! Homework is due on paper at the start of class on the day indicated (usually Friday). Exceptions will be made only by advance arrangement (excepting "acts of God"). Late work must be turned in to the TA's mailbox (ask the CS receptionist in 14 MLH for help). Never push homework under someone's door!

1. Background: Consider the logic circuit shown to the right. If the function inputs on the left, f₁ to f₇ are all set to one, the circuit behaves exactly like the adder circuit shown in the notes.

   Assume, in the following, that 32 of these modified adders are ganged up with the carry connections as usual for adders and used to combine two 32-bit binary numbers a and b to produce a 32-bit result s. All f inputs are set to one unless specified otherwise in the following questions:

   a) Suppose f₃, f₅ and f₆ are set to zero, and c₀ is also set to zero. What effect does this have the carry outputs from the modified adder? (0.5 points)

   b) Suppose f₃, f₅ and f₆ are set to zero, and c₀ is also set to zero, as in part a). What is s as a function of a and b. (0.5 points)

2. Exercises from Chapter 9 of the Notes:

   d) (0.5 points).

   g) (0.5 points)

   n) (1.0 points).