Nothing has been done with the flash content of the stm32f407, but its content has changed.

[LucyLiu]

Hi, I'm Lucy. I've come across a difficulty that I can't solve. I was hoping you could help me see what the problem is.

One of my programs uses IAP. The APP program starts at 0x8020000. After the APP program worked properly for a while, the APP program would not run. So I read the content of the non-running FLASH and compared it with the content of the normal running FLASH. I checked the code and there is no operation of FLSH, what else could cause this?

 

Edit: This post has been translated from Chinese to comply with the ST Community guidelines.

[Uwe Bonnes]

Change happened from some bits still unprogramm to all bits programmed(0x00). The only reason I can think of is some part of the program running amoc. Radiation, extrem high temperature and similar will make the bit cells loose charge ans return to the unprogrammed state (0xff).
Look first for the probable cause!

[LucyLiu]

Thank you very much for your reply. Could you please explain "amoc" to me?

[Andrew Neil]

https://dictionary.cambridge.org/dictionary/english/run-amok

[Andrew Neil]

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@LucyLiu wrote:

I checked the code and there is no operation of FLSH, .

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But you said the code does IAP - how can it do that without any Flash operations?

Also, does it emulate EEPROM in Flash?

[LucyLiu]

Sorry, I didn't make myself clear. When I say no operation on FLASH, I mean no operation after the code works properly.

[unsigned_char_array]

Have you disabled download in your debug configuration?
If you start a debug session the debugger will reflash the target unless you uncheck download.