SI Timing & Noise: Tricky Q&A

Section Q&A bank

Use these drills after completing all topics in SI Timing & Noise. Answer with corner/mode/view, path group, metric, artifact, ECO, and regression.

What is delta delay?

[INT][STA][SI-TIMING]

Q: What is delta delay?

A:
Extra delay on victim net due to switching aggressors — SI effect on timing.

FOLLOW-UP TRAP: Ignoring SI after timing ECO.

Noise vs delta delay?

[INT][STA][SI-TIMING]

Q: Noise vs delta delay?

A:
Delta delay changes timing; noise glitch risks functional wrong data on inputs.

FOLLOW-UP TRAP: Fixing only setup without noise check.

Q&A drill guide

CONSTRAINT -> VIEW -> PATH -> METRIC -> ECO -> REGRESSION

Sketch while answering

SI ON VICTIM

victim net delay = base_RC + coupling_from_aggressors

Key takeaways

• State corner, mode, view, and database tag with every slack claim.

• Run setup and hold plus MMMC regression after every ECO.

Common pitfalls

• Comparing STA runs with different SPEF or SDC tags.

• Broad false_path to green-wash violations.

• Setup-only ECO without hold check.