It’s easy to design logic circuits. Simply draw up a truth table, showing what the output should be for each combination of the input, then use Karnaugh Maps to simplify the boolean expressions, then draw the logic diagram…

Send me an email if you want more detail on how any of these circuits were designed.

Electronic Dice:

The combinational logic decodes the input and displays the count in a dice pattern. Use the 0 to 5 Synchronous counter below to provide the input (increase the clock frequency so you can’t see the dice rolling).

7 Segment decoder:

Decodes the 4 bit input to display 0 to 9. Use the Asynchronous counter below as the input. Note that the counter counts 0 to F, and the decoder only decodes 0 to 9.

Full Adder:

Takes two bits and adds them. For more bits, connect the Cout to Cin of the next stage.

Synchronous Counter (0 to 5):

Uses JK flip flops to count from 0 to 5.

Asyncronous Counter (0 to F):

Uses D type flip flops to count from 0 to F.