Using a J–K flip-flop in a design: Evaluate the statement “To determine the next outputs, we only need to consider the levels at J and K at the active clock edge.” Assess whether this captures the core edge-triggered behavior (ignoring asynchronous controls and timing violations).

Introduction / Context: The J–K flip-flop is edge-triggered in most logic families, meaning the next state is determined by inputs sampled at a specific clock edge. This question evaluates whether considering J and K only at the active edge is sufficient to determine the next state under normal, synchronous operating conditions.

Given Data / Assumptions:

• We are dealing with an edge-triggered J–K flip-flop.
• Asynchronous preset/clear, if present, are inactive.
• Setup and hold time requirements for J and K are met (no metastability).

Concept / Approach: For an edge-triggered device, inputs are effectively sampled at the clock edge. The J–K characteristic table then determines the next state: J=0,K=0→no change; J=1,K=0→set; J=0,K=1→reset; J=1,K=1→toggle. Provided timing constraints are met, the values at that instant fully define the next output.

Step-by-Step Solution:

Verification / Alternative check: Simulations and datasheets confirm that, absent violations and asynchronous actions, only edge-sampled values determine Q(n+1).

Why Other Options Are Wrong: “Incorrect” would imply level-sensitive behavior, which contradicts edge-triggered operation. Limiting correctness to J=K or a specific edge polarity misunderstands the general rule.

Common Pitfalls: Ignoring setup/hold, which can invalidate the assumption. Also, forgetting asynchronous set/clear can override edge-determined behavior if asserted.

Final Answer: Correct