23.6.3.4.2 Leaving Battery Backup Mode

Leaving backup mode can be triggered by either:

• RTC requests and externally triggered RSTC requests, under one of these conditions:
  • The Backup Domain is supplied by Main Power, and the Battery Backup Power Switch is not forced (BBPS.CONF not set to FORCED)
  • The Battery Backup Power Switch is forced (BBPS.CONF is FORCED)
  The device is kept in battery-powered backup mode until Main Power is restored to supply the device. Then, the backup domain will be powered by Main Power.
• Automatic Power Switch. Leaving backup mode will happen when Main Power is restored and the Battery Backup Power Switch configuration (BBPS.CONF) is set to APWS: When BBPS.WAKEEN=1, the device will leave backup mode and wake up.

  When BBPS.WAKEEN=0, the backup domain will be powered by Main Power, but the device will stay in backup mode.

• PSOK pin. A low-to-high transition on PSOK will wake up the device if BBPS.PSOKEN=1, BBPS.WAKEEN=1, and the Battery Backup Power Switch is different from APWS (BBPS.CONF is not APWS).

  When BBPS.WAKEEN=0, the backup domain will be powered by Main Power, but the device will stay in backup mode.