How to implement a 3 bit asynchronous odd counter with JK flip flops - Quora
Synchronous counter
Synchronous counter
DeldSim - 4-Bit Down Counter
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
Solved I need the Verilog code for 4 bit Synchronous Up/Down | Chegg.com