76. Design 4-bit Asynchronous Up counter

Asynchronous Circuits: Memory elements operate independently and do not share a common centralized clock line.

Asynchronous Counters: Also called ripple counters; the output of one stage acts as the clock for the next stage, cascading the state change down the line.

Pause/Play Logic: Tying all T inputs to hold the system data when T=0, and enables toggling when T=1.

Advantages: Minimal wiring requirements, lower hardware density, and easy expansion due to the elimination of complex carry-lookahead circuitry.

Disadvantages: Cumulative propagation delay accumulates across stages, creating transient states and rendering the system unsafe for high-speed operation.