Lab 3-Don't Care Conditions

[Arun Sharma]

Hi all,

We were just wondering about don't care conditions.

When doing our Karnaugh maps from the State Diags, we came across
conditions that should never exist (such as Ba & Bg both being on).
Should we make these into don't care conditions or should we have them
continue on in the same state that they are currently in.

Thanks,
Arun

[Muhammad M. Khellah]

Ba and Bg are outputs that are fed back to the state machine (control
block). If you design according to the lab specs, the case where
Ba=Bg=1 should never occur. Thus in the state table, you will only need
the following combinations:

Ba Bg
1 X
X 1
0 X
X 0
X X

-- M. M. Khellah