Find and correct the mistakes: Synchronous N.E.T. JK-FF mod-15 up counter

Thread Starter

ssddssdd

Joined Feb 29, 2020
2
We are given this counter diagram:
7777ee - Copy.png

And we must locate the mistakes and correct them, to make sure it's a synchronous mod-15 counter.
Now, from what I've tried it should look like this:

7777ee - Copy - Copy.png
So when it reads 1110 (14), it resets the counter to 0000.
Is my answer correct?
 
Last edited:

dl324

Joined Mar 30, 2015
10,720
Welcome to AAC!
So when it reads 1110 (14), it resets the counter to 0000.
Is my answer correct?
Your answer in incorrect.

Do you have this circuit in a simulator? If so, what does it show happening during the transition from 13 to 14?
 

Thread Starter

ssddssdd

Joined Feb 29, 2020
2
Welcome to AAC!
Your answer in incorrect.

Do you have this circuit in a simulator? If so, what does it show happening during the transition from 13 to 14?
Thank you.

No I don't, it's supposed to be hand-drawn using Karnaugh etc. and I tried solving it as is.
 

WBahn

Joined Mar 31, 2012
25,745
For starters, your proposed solution is not a synchronous counter because you are using the asynchronous resets as part of the normal operation. Note that even the original circuit did not use (or even have) the resets.
 
Top