9.3.5 Sleep Mode Operation
If there is no ongoing write operation, the NVMCTRL will enter sleep mode when the system enters sleep mode.
If a write operation is ongoing when the system enters a sleep mode, the NVM block, the NVM Controller and the system clock will remain on until the write is finished. This is valid for all sleep modes, including Power Down sleep mode.
The EEPROM Ready interrupt will wake up the device only from Idle sleep mode.
The page buffer is cleared when waking up from sleep.