Mechanism for Retention Register Design focuses on retention coverage %, restore mismatch count, and retained state corruption escapes. The goal is to link observed behavior to power-intent mechanism, ownership, and release risk.
Retention flops preserve selected state through power collapse by copying data into retention latches powered by an always-on supply. Read this topic as an executable contract: power states, boundary policies, and transition sequencing must agree across architecture, UPF, RTL, and implementation.
Identify state transition where failure appears first.
Identify source and destination domains plus crossing policy.
Identify control signal origin and sequencing requirements.
POWER INTENT FLOW — Retention Register Design
architecture intent
|
v
UPF objects (domain/supply/state/strategy)
|
v
RTL + synthesis + PD interpretation
|
v
verification + signoff evidence
|
v
release decision
Primary metric: retention coverage %, restore mismatch count, and retained state corruption escapesRETENTION FLOP MODEL
functional FF ----save----> retention latch (AON rail)
functional FF <---restore-- retention latch
retention_supply must remain alive through collapse.LP OWNERSHIP LAYERS — Retention Register Design
layer owns typical failure
------------------ --------------------------- --------------------------
architecture domain strategy infeasible power states
UPF intent policy objects + bindings wrong/missing policy
implementation LP cell insertion/routing illegal physical behavior
verification transition scenarios uncovered LP bug
signoff governance waiver + release decisions late escape to siliconIsolation and retention are sequence-sensitive contracts, not static checkboxes.
SEQUENCE
save -> isolate -> power-off -> power-on -> restore -> releaseTRANSITION DEFECT MIX
polarity errors ███████
late iso assertion █████
restore ordering ████isolation crossing report
retention list
save/restore timing
X-propagation log
A late isolation enable caused intermittent X leaks only on one PMU path.
Validate control polarity
Trace AON source
Replay transition waveform
Ask: what transition evidence proves this topic is closed, and which owner signs it?
State transition context must accompany every low-power metric claim.
Intent changes require simulation, formal, and implementation re-validation.
Comparing results from mismatched UPF revisions.
Assuming static checks replace transition validation.
Shipping with aged waivers and unclear ownership.
Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 1
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 2
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 3
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 4
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 5
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 6
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 7
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 8
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 9
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 10
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 11
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 12
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Use this pack to rehearse low-power closure on low-power/isolation-retention/retention-register-design/mechanism: transition framing, policy ownership, implementation evidence, and release confidence.
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.
Which policy object is first to deviate from intent?
Which owner can apply the smallest reversible fix?
What regression matrix proves no collateral damage?
Which waiver conditions would still block release?
LP EVIDENCE CAPSULE 13
PATH: low-power/isolation-retention/retention-register-design/mechanism
STATE WINDOW: <from -> to>
POLICY OBJECT: <isolation / retention / shifter / switch>
OWNER: <name>
PRIMARY ARTIFACT: <report/waveform/formal result>
RELEASE DECISION: <close / bounded waiver / escalate>Retention flops preserve selected state through power collapse by copying data into retention latches powered by an always-on supply.
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