Step-by-step analysis walkthrough

Use this when you own Data Validity Debug during an AMS war room.

1. Capture failing mode and environmental condition.

2. Pull synchronized waveform, logs, and report artifacts.

3. Mark first boundary where legal behavior diverges.

4. Audit reset/clock/power sequence assumptions.

5. Check physical coupling contributors (floorplan/power/package) where relevant.

6. Assign single-thread ownership for the first fix.

7. Propose bounded change and define success criterion.

8. Run scenario and safety regressions.

9. Document findings in closure memo.

10. Update signoff dashboard and waiver state.

Artifacts to collect

• validity checker report, sampled trace set, anomaly triage memo

• handoff contract

• firmware/config tag

• physical signoff snapshot

• decision memo

Decision memo template

AMS DECISION MEMO — Data Validity Debug
mode/condition:
metric:
hypothesis:
fix:
regression:
owners: signal-processing owner, RTL owner, system validation lead

Reference visuals

Data validity checks

frame valid + saturation flag + sequence integrity + freshness
all must pass before data is trusted.

AMS deep dive

Wrapper and sampling contracts determine data trustworthiness.

Concept diagram

CONVERTER DATA FLOW

sampling clock -> wrapper -> sync boundary -> system consumer

Metric graph

INVALID SAMPLE BURSTS

time --->  _|¯¯|__|¯¯¯|____|¯|_

Reports and artifacts

• sample validity ratio

• calibration convergence

• CDC audit

• overflow/stale sample counters

Mini case study

Mode transition changed sample phase and invalidated wrapper framing assumptions.

Debug branches

• Sample timing contract

• Calibration hook behavior

• Wrapper CDC integrity

Senior review question

Ask: what boundary condition proves this topic is actually closed?

Key takeaways

• State boundary, mode, and evidence tag with every claim.

• Always align analog, digital, and physical owners before signoff decisions.

Common pitfalls

• Fixing averages while tails still fail.

• Skipping package/supply evidence in jitter or SerDes issues.

• Shipping with waivers that lack owner and expiration criteria.

Principal AMS review addendum

Data validity must combine framing correctness, saturation/overflow signaling, and synchronization sanity so software trusts converter samples.

Metric: invalid sample bursts, clipping incidents, stale-data escapes