Hello Leopoldo,
Indeed, during reset events, the contents of NVPROT and NVOPT in the reserved flash memory are transferred into corresponding FPROT and FOPT registers in the high-page registers area to control security and block protection options.
In order to get more detailed information, please refer to Chapter 4.6.2.4 at the Reference Manual from the following link:
I hope this information will be useful for you.
If I misunderstood your question, feel free to let me know. I will be glad to help.
Have a great day.
David Diaz.
Thanks David, as I understand, but my English is medium.