26 Power Manager

Standby SleepWalking Mode

When the device enters Standby sleep mode with an active host, APB clock-domain crossings and periodic RTC-related events may repeatedly request clocks. This can cause excessive clock activity and repeated start/stop cycling of the GEN0 oscillator, resulting in higher-than-expected Standby power consumption.

The issue is more likely when the active host is configured for ONDEMAND operation rather than RunStandby.

Workaround

To reduce recurring clock requests in Standby:

  • Set the RTC prescaler to 0 to disable periodic interval events, or
  • Configure GEN0 as ALWAYS_ON instead of ONDEMAND to prevent oscillator start/stop cycling

For maximum effectiveness, apply both settings. This disables RTC periodic intervals and keeps GEN0 continuously running, allowing the RPMU to remain in STANDBY NO-SLEEP-WALKING when the ONDEMAND host is idle.

Affected Silicon Revisions

A1A2
X