__HAL_PWR_GET_FLAG macro

specifies the flag to check. This parameter can be one of the following values: @arg PWR_FLAG_WU: Wake Up flag. This flag indicates that a wakeup event was received from the WKUP pin or from the RTC alarm (Alarm A or Alarm B), RTC Tamper event, RTC TimeStamp event or RTC Wakeup. An additional wakeup event is detected if the WKUP pin is enabled (by setting the EWUP bit) when the WKUP pin level is already high. @arg PWR_FLAG_SB: StandBy flag. This flag indicates that the system was resumed from StandBy mode. @arg PWR_FLAG_PVDO: PVD Output. This flag is valid only if PVD is enabled by the HAL_PWR_EnablePVD() function. The PVD is stopped by Standby mode For this reason, this bit is equal to 0 after Standby or reset until the PVDE bit is set. @arg PWR_FLAG_BRR: Backup regulator ready flag. This bit is not reset when the device wakes up from Standby mode or by a system reset or power reset. @arg PWR_FLAG_VOSRDY: This flag indicates that the Regulator voltage scaling output selection is ready.