Mod 16 ripple down counter and Mod 12 ripple down counter

[eutynem]

1. How do you force a mod 16 down counter into a mod 12 down counter at any time. The mod 16 has been designed and build using the 74ls76 chip.

2. Then design and build the gate logic to detect the counter reset state.

3.  Use the output of the reset state detector (step 2) to activate the initial state circuit (Step 2)

Any help would be appreciated.  Diagrams too.  Am building this on the hard white breadboard....

 

[Hero999]

You use logic gates to detect when the counter has reached 12 and connect to output to the counter's reset pin.