1. Synchronous counters - The counters which use clock signal to change their transition are called “Synchronous counters”. The synchronous counters depends on their clock input to change state values. In synchronous counters, all flip flops are connected to the same clock signal and all flip flops will trigger at the same time.

2. 4 Bit Synchronous Up Counter - The inputs of first flip flop  are connected to HIGH (logic 1), which makes the flip flop to toggle, for every clock pulse entered into it. So the synchronous counter will work with single clock signal and changes its state with each pulse.

3. In the up counter the 4 bit binary sequence starts from 0000 and increments up to 1111.

4. Working of Synchronous Counter