Problem 2 - Digital Design

Design a digital key which opens by an input 1, 1, 0, 0, 1.

1.

Draw a state diagram.

2.

Obtain a state table.

3.

Obtain an excitation table.

4.

Obtain logic equations and draw a logic diagram.

1.

$$\includegraphics{digital-key-state-diagram.ps}$$

2.

$$\begin{tabular}{c\vert cc} & \multicolumn{2}{\vert c}{Next state}... ... 010 & 011 & 000 \\ 011 & 100 & 000 \\ 100 & 000 & 101 \\ \end{tabular}$$

3.

$$\begin{tabular}{cc\vert cc} \multicolumn{2}{c\vert}{Inputs of the... ... 0 & 0 \\ 1 0 0 & 1 & 1 0 1 & 1 \\ 1 0 0 & 0 & 0 0 0 & 0 \\ \end{tabular}$$

4.

101X, 110X, and 111X are don't-care conditions.

$$\includegraphics{karnaugh-maps-digital-key.ps}$$