Assignment 11, due Nov 11

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 this circuit: It is some kind of flipflop (hence the Q label on the output). The problem is to figure out what kind of flopflop, but we will work this in stages:

   a) Give a timing diagram showing how Q responds when the inputs change: Inputs a and b should both go through the following values:

   a 00010010111100010
   b 01000111101001000
   

   Neatness counts. Use a ruler if you can't draw a straight line. Use graph paper if you have trouble getting uniform spacing! You may want to graph not only the inputs and outputs, but also one or more of the intermediate values. (0.5 points).

   b) How do you set this flipflop? (0.2 points).

   c) How do you reset this flipflop? (0.2 points).

   d) What type of flipflop is it -- in terms of overall behavior. (0.2 points).

   e) Now consider a second closely related circuit, as shown to the right. What is it? That is, give its full descriptive name that completely describes its function. (0.4 points).

2. Problems from Chapter 12 of the notes:

   h) (0.5 point)

3. Problems from Chapter 13 of the notes:

   c) (0.5 point)

4. A Problem: The Hawk hardware responds to illegal memory accesses by forcing a bus trap. The output on the display screen that follows a trap is put there by the trap handler in the Hawk monitor. Explain the meaning of this output, and for those values in the output that the trap handler gets from the CPU, explain how it gets them. Note that the entire source code for the Hawk monitor is available on line, and you are welcome to read it, but your answer must not quote code so much as explain it. (0.5 points)