Difficulty: Medium
Correct Answer: The inputs to a trigger device are changing at the same time as the active trigger edge.
Explanation:
Introduction / Context:
A race condition in sequential logic occurs when signals that should be stable during the sampling event change too close to the active clock edge, potentially violating setup or hold requirements and causing unpredictable outputs or metastability.
Given Data / Assumptions:
Concept / Approach:
When inputs transition during the aperture window around the clock edge, internal latches can capture inconsistent states, leading to raced or metastable outcomes. Ensuring ts and th margins avoids races.
Step-by-Step Solution:
Verification / Alternative check:
Static timing analysis should show positive slack for ts and th; oscilloscope capture reveals glitches if violated.
Why Other Options Are Wrong:
Common Pitfalls:
Feeding asynchronous inputs directly to synchronous logic without synchronization, and neglecting clock skew while budgeting ts/th.
Final Answer:
The inputs to a trigger device are changing at the same time as the active trigger edge.
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