Compare counter types: Evaluate the statement “An asynchronous counter differs from a synchronous counter in the method of clocking.” Choose whether this distinction correctly captures their key difference.

Introduction / Context:
Understanding how counters are clocked is crucial for predicting timing behavior, maximum frequency, and glitch susceptibility. This question asks whether the defining difference between asynchronous (ripple) and synchronous counters is indeed their method of clocking.

Given Data / Assumptions:

• Asynchronous (ripple) counters: only the first flip-flop is clocked externally; subsequent stages are clocked by preceding outputs.
• Synchronous counters: all flip-flops receive the same external clock simultaneously.
• Other aspects (encoding, modulus) are independent of the clocking method.

Concept / Approach:
The clocking method drives the key behavioral differences: asynchronous counters exhibit ripple delays and potential decoding glitches; synchronous counters minimize skew between stages and support higher reliable speeds. Thus, “method of clocking” summarizes the core distinction accurately.

Step-by-Step Solution:

Verification / Alternative check:
Examine timing diagrams; asynchronous outputs change sequentially, synchronous outputs change together (after propagation delay from the same edge).

Why Other Options Are Wrong:
Tying the distinction to Johnson or BCD counters confuses code/modulus with clocking. “Incorrect” would deny a standard textbook definition.

Common Pitfalls:
Overlooking skew and routing in synchronous designs; although clocking is simultaneous in intent, physical skew must be controlled to maintain timing margins.

Final Answer:
Correct