OCV, AOCV, POCV & Variation: Tricky Q&A

Section Q&A bank

Use these drills after completing all topics in OCV, AOCV, POCV & Variation. Answer with corner/mode/view, path group, metric, artifact, ECO, and regression.

OCV vs AOCV?

[INT][STA][VARIATION-TIMING]

Q: OCV vs AOCV?

A:
OCV applies fixed derate; AOCV reduces derate with path depth to cut over-pessimism.

FOLLOW-UP TRAP: Assuming AOCV helps hold automatically.

Why are short paths hold-sensitive?

[INT][STA][VARIATION-TIMING]

Q: Why are short paths hold-sensitive?

A:
Min-delay analysis with variation can fail on short logic depths after setup ECO.

FOLLOW-UP TRAP: Setup-only regression.

Q&A drill guide

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

Sketch while answering

VARIATION STACK

nominal delay + OCV/AOCV/POCV margin = signoff delay

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.