Sample interview questions: Can you discuss your familiarity with different clock domain crossing (CDC) analysis and mitigation techniques?
Sample answer:
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Clock Domain Crossing (CDC) Analysis Techniques:
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Static Timing Analysis (STA):
- Industry standard approach for CDC analysis.
- Identifies potential CDC violations by comparing the arrival and required times of signals crossing clock domains.
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Formal Verification:
- Exhaustive analysis technique that can detect all potential CDC violations.
- Computationally intensive and may not be practical for large designs.
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Simulation:
- Dynamic analysis technique that can be used to verify the effectiveness of CDC mitigation techniques.
- May not be able to detect all potential CDC violations, especially in large designs.
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CDC Mitigation Techniques:
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Synchronous Clock Crossing:
- Use a single clock source for all domains.
- Phase shift the clocks to ensure that data is stable at the crossing point.
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Asynchronous Clock Crossing:
- Use separate clock sources for different domains.
- Employ handshake protocols or FIFOs to transfer data between domains.
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Clock Gating: Read full answer
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