Low Power Verification · All levels

Power Bug Triage: Worked Example

Worked Example for Power Bug Triage.

Worked example

Worked Example for Power Bug Triage is anchored on illegal transition rate, corruption incidence, and deterministic replay quality under low-power scenarios. Convert observations into mechanism-backed and owner-bound actions.

A regression appears in illegal transition rate, corruption incidence, and deterministic replay quality under low-power scenarios. Strong closure isolates first failing boundary, proves mechanism, applies one reversible fix, and validates blast radius before release.

Execution lens

diagram
LOW-POWER VERIFICATION FLOW - Power Bug Triage

power intent and mode definitions
      |
      v
domain controls and transition sequencing
      |
      v
simulation behavior (isolation, retention, corruption)
      |
      v
assertions and coverage evidence
      |
      v
triage, bounded fix, and signoff closure

Decision matrix

diagram
EVIDENCE MATRIX - Power Bug Triage

+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| Evidence                    | Tells you                      | Does not prove                 | Next action               |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| transition timeline traces  | first failing LP phase         | complete root-cause ownership  | correlate with intent map |
| UPF-aware assertion logs    | contract violations by phase   | silicon product impact         | map to scenario severity  |
| corruption/X classification | actionable vs noisy failures   | legal transition completeness  | replay key mode corners   |
| save/restore snapshots      | state integrity movement       | isolation correctness          | pair with crossing checks |
| before-after regressions    | mitigation movement quality    | long-tail stability            | run full matrix           |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+

Low-power verification deep dive

Signoff confidence comes from triage discipline, reproducible proof, and explicit residual-risk decisions.

Concept diagram

diagram
LPV SIGNOFF LADDER

reproduce -> classify -> isolate boundary -> bounded fix -> replay -> signoff decision

Metric graph

diagram
SIGNOFF CONFIDENCE

open ambiguous failures  ██████
reproducible closures    ███████
residual-risk unknowns   ███

Metrics and artifacts to collect

  • X-prop triage classification report

  • bug root-cause closure packet

  • regression stability and recurrence trend

  • signoff checklist completion matrix

Mini case study

A signoff block cleared after the team replaced broad waivers with boundary-specific evidence and replay criteria.

Debug branches

  • Classify X behavior before broad waiving.

  • Capture one definitive artifact packet per closure claim.

  • Define residual risk and rollback path at signoff.

Senior review question

Ask: what exact low-power transition boundary failed first, and which artifact proves the closure claim reproducibly?

Key takeaways

  • Tie each LPV claim to a concrete transition boundary and one proving artifact.

  • Prefer minimal reversible fixes with explicit owner and rollback criteria.

Common pitfalls

  • Treating power-aware failures as random before boundary classification.

  • Waiving X-prop failures before proving impact and root cause.

  • Declaring closure without deterministic replay across key modes.

Worked-example reasoning

Start by proving phase and boundary assumptions before tuning checks.

Use one reversible change per hypothesis to preserve causality.