 I would like to address now the specific case of STM32-L4 family. For this family, the algorithm is slightly different. In fact, once you program the option byte ADP, any execution from Flash will be seen as an intrusion, so the Flash will be locked. The solution is to execute from RAM the change of ADP level on author's entering standby mode. You can see here the code snippet of the function that we will do in RAM. We don't use hashL because we want just to have a register access to ensure everything is executed from RAM. First, I do the hobby launch. This one will reload the option byte. But no reset generated, and I need also to trigger the enter and standby mode to erase the debugging flag. It's what I'm doing here. Associated with this addendum, I did review a full project that have been tested on the Nucleo F446RE. Thanks for your attention.