RM0383 Rev 3 3.8.6 Flash option control register (FLASH_OPTCR) maybe wrong default value

[Uwe Bonnes]

To whom it may concern:

RM0383 Rev 3 for the STM32F411 on page 63 states as default value for

3.8.6 Flash option control register (FLASH_OPTCR)

a default value 0x0FFF AAED

Value read back on a new device is however 0x00FF AAED

This fits more with bits 24-30 in the bitfield explanation marked as reserved.

[Imen.D]

Hello,

If you put flash sectors (0 to 5), as non protected: all the nWRP bits are at “1�?, also the reserved bits;

When change one sector to PCROP, you will see that the polarity of these bits are inverted, reserved bits included.

So, the default value in the RM is correct. If a die is brand new (without change from factory), you should have the reset value as states in the doc,

But, if PCROP is selected on one sector, the polarity is inverted also for the reserved sectors. (and the other sectors needs to be not protected or PCROP protected, since a mix PCROP and write protect is not allowed) 

Best Regards,

Imen