When turning in a homework problem, mark it with the exercise number shown in bold here. These will be the reference numbers I use in reporting back your standing on the homework.
C.x1: Consider the following truth table:
| inputs | outputs | |||
|---|---|---|---|---|
| A | B | C | D | E |
| 0 | 0 | 0 | 1 | 0 |
| 0 | 0 | 1 | 0 | 1 |
| 0 | 1 | 0 | 1 | 0 |
| 0 | 1 | 1 | 0 | 1 |
| 1 | 0 | 0 | 1 | 1 |
| 1 | 0 | 1 | 0 | 1 |
| 1 | 1 | 0 | 0 | 0 |
| 1 | 1 | 1 | 0 | 1 |
Use input don't cares to rewrite the truth table using only four rows.
Use your reduced truth table as the basis for drawing a PLA in the style of Figure C.3.5 on page C-16. Your PLA should have as few product terms as possible.
C.x2: A state machine with three states has the following next-state function:
| inputs | outputs | |||
|---|---|---|---|---|
| S1 | S0 | B | NS1 | NS0 |
| 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 0 | 1 |
| 0 | 1 | 0 | 1 | 0 |
| 0 | 1 | 1 | 0 | 0 |
| 1 | 0 | 0 | 1 | 0 |
| 1 | 0 | 1 | 0 | 1 |
| 1 | 1 | X | X | X |
In this table, S1 and S0 encode the current state, NS1 and NS0 encode the next state, and B is the single input to the state machine.
The last row in the table has two output don't cares as well as an input don't care. Briefly explain why.
Draw a diagram of the three states in the style of Figure C.10.2 on page C-70. Because you are not given any information about outputs from the state machine, you won't show anything inside the circles. The states in Figure C.10.2 are labeled with the names NSgreen and EWgreen; your three states should instead be labeled with their S1 and S0 values. For example, write 01 next to the state that has S1=0 and S0=1. Label the arrows appropriately.
Instructor: Max Hailperin