I'm trying to design an asynchronous counter with JK flip- flops, with an arbitrary sequence.
The sequence is: 0,1,10,11,0,5,14,15.
I know how to solve this kind of problems, but in this case the sequence repeats one number, 0.
I want to solve this like this guy: https://www.youtube.com/watch?v=Zce6NlHuvfs
But I don't how to manage the problem of the repetition of one number in the sequence.
Any idea?
Thanks in advance.
Best Answer
If you write down the mapping of count states 0-7 to outputs
You see that
O0 = C0
O1 = O3 = C1
O2 = (C0 OR C1) AND C2
So you can accomplish that simply with a 3 bit counter one OR and one AND gate:
simulate this circuit – Schematic created using CircuitLab
Note: there is, however, a so-called hazard between count state 5 and 6, i.e. there might be multiple edges before the signal settles to the new state. That won't be a problem if you don't care about output edges, only about levels.