Silicon impact and release risk

Coverage gaps in transitions become expensive silicon escapes.

Area drivers

• isolation and retention cell overhead

• switch bank footprint

• AON routing resources

Power drivers

• AON leakage budget

• switch control overhead

• wake-up transient penalties

Timing and latency impact

• transition latency

• crossing delay through LP cells

• mode-dependent timing drift

PD consequences

• rail partitioning constraints

• IR under staged wake-up

• placement legality for LP cells

Verification burden

• transition IR checks

• formal LP proofs

• waiver revalidation

PPA / ROBUSTNESS — Isolation Coverage
area/power/latency/robustness trade envelope

PPA takeaways

• Low-power correctness has direct silicon reliability impact

• Transition-mode signoff is mandatory

Design option impact snapshot

BEFORE / AFTER FIX — Isolation Coverage

metric quality
  ^
  |                       o target region
  |                 o post-fix + regression
  |            o
  |      o failing baseline
  +----------------------------------------> iteration
      sequence audit   policy fix   full re-run

Low-power deep dive

Transition-centric verification closes LP risk better than active-mode-centric regressions.

Concept diagram

VERIFY LOOP

transition matrix -> simulation + formal -> coverage -> closure

Metric graph

COVERAGE CLOSURE

state transitions covered   ███████████
isolation activation        █████████
retention restore paths     ████████

Reports and artifacts

• state coverage

• formal LP properties

• isolation coverage

• LP bug triage dashboard

Mini case study

Coverage looked high, but one untested OFF->RUN transition hid a restore race.

Debug branches

• Rank by transition criticality

• Correlate PMU logs with failures

• Escalate unproven properties

Senior review question

Ask: what transition evidence proves this topic is closed, and which owner signs it?

Key takeaways

• State transition context must accompany every low-power metric claim.

• Intent changes require simulation, formal, and implementation re-validation.

Common pitfalls

• Comparing results from mismatched UPF revisions.

• Assuming static checks replace transition validation.

• Shipping with aged waivers and unclear ownership.

Execution drill pack 1

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 1

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 2

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 2

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 3

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 3

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 4

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 4

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 5

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 5

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 6

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 6

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 7

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 7

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 8

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 8

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 9

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 9

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 10

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 10

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 11

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 11

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 12

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 12

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Execution drill pack 13

Use this pack to rehearse low-power closure on low-power/low-power-verification/isolation-coverage/silicon-ppa-impact: transition framing, policy ownership, implementation evidence, and release confidence.

Transition checklist

• State transition explicitly named with legal source/target states.

• Crossing and domain ownership are mapped and agreed.

• Policy controls are traced to always-on source logic.

• Waveform bookmarks align controls with state timestamps.

Review prompts

1. Which policy object is first to deviate from intent?

2. Which owner can apply the smallest reversible fix?

3. What regression matrix proves no collateral damage?

4. Which waiver conditions would still block release?

Evidence capsule

LP EVIDENCE CAPSULE 13

PATH: low-power/low-power-verification/isolation-coverage/silicon-ppa-impact
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>

Principal LP review addendum

Coverage must prove every required crossing is isolated under relevant OFF states and that clamps match downstream protocol assumptions.

Metric: isolation activation coverage, clamp-value observability, and crossing protection completeness