56.4.5.2 Fuse Programming

All the fuses can be written by software.

The sequence to program fuses is the following:

1. Write the key code 0xFB in the Key register (SFC_KR).
2. Write the word to program in the corresponding SFC_DRx.
For example, if fuses 0 to 31 must be programmed, SFC_DR0 must be written. If fuses 32 to 61 must be programmed, SFC_DR1 must be written. Only the data bits set to level ‘1’ are programmed.
3. Wait for flag SFC_SR.PGMC to rise by polling or interrupt.
4. Check the value of flag PGMF. If it is set to 1, the programming procedure has failed.

After programming, the fuses are read back in the corresponding SFC_DRx.