BSSRR register
Hi,
You can have a look in the GPIO examples in CUBE HAL L4.
I don’t know if they use BSSRR reg but at least there is a GPIO toggle example.
You can import it in SW4STM32.
Also for STM32L4R5ZI SD card, you can have a look in the demo or in the FatFs Application in the cube L4 (Disco or Eval L4R9I).
Rgds,
Laurent