Solved
Is CFG_HW_PWR_STANDBY_SEMID really only used in STM3215xx devices to go into standby?
It seems odd that this semaphore doesn’t apply across the entire STM32WB family. Is this really the case, and if so, why?
Remy ISSALYSBest answer
ST Technical Moderator
August 18, 2026
Hello,
On STM32WB55, STOP2 is the deepest low power mode supported when RF is active. When the user application must enter Standby mode, it must first stop all RF activities, and fully reinitialize CPU2 when coming out of Standby mode.
On STM32WB15, the deepest low power mode supported when RF is active is STANDBY, that’s why the CFG_HW_PWR_STANDBY_SEMID semaphore is used only in STM32WB15 project (like BLE_HeartRate).
Best Regards,