How to design a synchronous counter 4 bit using JK flip flop that can count up even numbers from 0 to 14, and count down odd numbers from 15 to 0 in 1 system - Quora
Synchronous counters
Design BCD (MOD-10) Ripple Counter using JK Flip-Flop || Sequential Logic Circuits - YouTube
Designing Synchronous Counters Using JK Flip Flops - YouTube
Synchronous 4-Bit counter circuit using JK-flip-flops | TikZ example