Bug when erasing flash STM32F412

> it will be impossible to write a correct reliable bootloader. 

That would be my interpretation as well, as doing a full erase would also erase your bootloader.

I have no background on this, but I imagine the errata was written by someone who didn't entirely understand the problem and, instead of figuring out the issue, came up with the lazy solution of "don't do that" instead.

There should be a relatively compatible STM32F4 chip you could use as a replacement. I don't see similar errata other members of the family:

https://www.st.com/resource/en/errata_sheet/dm00037591-stm32f405-407xx-and-stm32f415-417xx-device-limitations-stmicroelectronics.pdf

Thanks for your feedback!

I chose the chip according to many criteria (USB with > 5 EP, 2 CAN, QSPI, SDIO, 2 UART, SPI, 2 I2C, 256kB of RAM and all this in an LQFP-64 package). The determining factor was the price. Our distributors have found this chip to be the cheapest among the STM32F4. And now I understand why. The saddest thing is that ST has no plans to fix this in future revisions:(

Errata sheet says that only first rev. , i.e. 'Z', is affected, whereas 'C' and '1' are not. Unfortunately the errata sheet doesn't doesn't tell when the particular revisions were introduced, but as there are already two more recent revisions not affected, it's quite likely 'Z' won't be shipped anymore by any official distributor.

Where did you read that?

I look here and see that this bug applies to all chip revisions:

https://www.st.com/resource/en/errata_sheet/dm00183231-stm32f412xexg-device-limitations-stmicroelectronics.pdf

I found it! Thanks!

I will contact our distributors and try to find out the revision of the chips.

Just checked a F412-Disco board I got in 2017 or 2018: Rev. 'C' from week 32 in 2016. So 'Z' is probably *very* early.