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.
23.6.4. Output Pins
The SUPC can drive two outputs. By writing a '1' to the corresponding Output Enable bit in the Backup
Output Control register (BKOUT.EN), the OUTx pin is driven by the SUPC.
The OUT pin can be set by writing a '1' to the corresponding Set Output bit in the Backup Output Control
register (BKOUT.SETx).
The OUT pin can be cleared by writing a '1' to the corresponding CLR bit (BKOUT.CLRx).
If a RTC Toggle Enable bit is written to '1' (BKOUT.RTCTGLx), the corresponding OUTx pin will toggle
when an RTC event occurs.
23.6.5. Brown-Out Detectors
23.6.5.1. Initialization
Before a Brown-Out Detector (BOD33) is enabled, it must be configured, as outlined by the following:
•
Set the BOD threshold level (BODVDD.LEVEL)
•
Set the configuration in active, standby, backup modes (BODVDD.ACTCDG,
BODVDD.STDBYCFG, BODVDD.BKUP)
•
Set the prescaling value if the BOD will run in sampling mode (BODVDD.PSEL)
•
Set the action and hysteresis (BODVDD.ACTION and BODVDD.HYST)
The BOD33 register is Enable-Protected, meaning that they can only be written when the respective BOD
is disabled (BOD33.ENABLE=0 and SYNCBUSY.BOD33EN=0). As long as the Enable bit is '1', any
writes to Enable-Protected registers will be discarded, and an APB error will be generated. The Enable
bits are not Enable-Protected.
23.6.5.2. Enabling, Disabling, and Resetting
After power or user reset, the BOD33 and BOD12 register values are loaded from the NVM User Row.
The BODVDD is enabled by writing a '1' to the Enable bit in the BOD control register (BOD33.ENABLE).
The BOD is disabled by writing a '0' to the BODVDD.ENABLE.
Related Links
23.6.5.3. 3.3V Brown-Out Detector (BOD33)
The 3.3V Brown-Out Detector (BOD33) is able to monitor either the VDD or the VBAT supply .
The Voltage Monitored bit in the BOD33 Control register (BOD33.VMON) selects which supply is
monitored in active and standby mode. In backup mode, BOD33 will always monitor the supply of the
backup domain, i.e. either VDD or VBAT.
If VDD is monitored, the BOD33 compares the voltage with the brown-out threshold level. This level is set
in the BOD33 Level field in the BOD33 register (BOD33.LEVEL). This level is used in all modes except
the backup sleep modes. In backup sleep modes, a different voltage reference is used, which is
configured by the
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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