Learning the Art of Electronics: 19L.1.4 Boolean Equations for Next States
We find it easer to see patterns in the truth table if we separate the state bits.
Here is the Truth Table for D1:
| Q1 Q0 | NS (start, stop) = | 00 | 01 | 10 | 11 |
|---|---|---|---|---|---|
| 00 | 0 | 1 | 0 | 1 | |
| 01 | 0 | 1 | 0 | 1 | |
| 11 | 1 | 1 | 1 | 1 | |
| 10 | 1 | 1 | 1 | 1 |
And here is the Truth Table for D0:
| Q1 Q0 | NS (start, stop) = | 00 | 01 | 10 | 11 |
|---|---|---|---|---|---|
| 00 | 0 | 0 | 1 | 0 | |
| 01 | 1 | 1 | 1 | 1 | |
| 11 | 1 | 1 | 1 | 1 | |
| 10 | 0 | 0 | 0 | 0 |
There cannot be any [unwanted] stuck states because all four possible states are used.