A control pulse crosses into a slower clock domain. Simulation was clean, yet bring-up logs show intermittent hangs under voltage droop and high temperature. This generic, illustrative scenario rehearses the hardest interview position: a failure the team did everything right and still missed, where the answer must cover evidence, fix, and process without blaming anyone.
Lesson | After it you can... |
|---|---|
State the bring-up symptom and why corner conditions implicate the crossing. | |
Sort bring-up logs, simulation results, and analysis reports into what each can and cannot prove. | |
Name the design fix and the review change that stops the next escape. |
The traps to avoid are given with the scenario: assuming noise without a crossing audit, relying on two flops for a one-cycle pulse without width analysis, and skipping liveness checks after the RTL patch.
Corners slow the flops and shrink timing margins, which widens the capture window and lengthens settling: a marginal crossing fails at the hot corner first while deterministic logic still passes.