Failed to erase an STM32F779NIH6 MCU

[Julien M]

Posted on July 19, 2017 at 16:05

Hello everybody,

I have some trouble when I want to erase my chip by  sector erase  or mass erase (ST LINK UTILITY with ST LINK dongle)   I obtain  some  dummy bytes after an erase operation like that :

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00 00 00 00 00 00 00 00 3C 29 00 08 29 21 00 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF BD 3B 00 08 BD 3B 00 08 00 00 00 00 BD 3B 00 08 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF BD 3B 00 08 BD 3B 00 08 00 00 00 00 BD 3B 00 08 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF BD 3B 00 08 BD 3B 00 08 18 08 00 00 BD 3B 00 08 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

Can I forget something ?

Normaly is filled by 0xFF ?

When I use this method on a STM32F103 it works well.

Of course when I try to put a firmware it become like a random firmware because the flash was not really erased.

Do you have some idea to help me ?

Thank you so much .

Julien.

[STOne-32 · Accepted solution]

Posted on July 20, 2017 at 20:09

Hi Julien,

Check all of our Hardware connections on board, including VDDs, VDDAs, VCAP Pins etc.. PDR_ON etc..

you can monitor VCAP pins with a voltmeter and check the value of ~1.2Volts.   Hope it helps you.

Cheers,

STOne-32.

[Julien M]

Posted on July 21, 2017 at 10:24

Hi ,

Thank you so much for your help,  my power path management  seems to be wrong in my custom board , but in another one it works fine. thank you so much.

[Julien M]

Posted on July 21, 2017 at 15:12

Hi, 

Thank you but I try to test my  other custom board (same batch) and I have some trouble STLINK tool can't erase all the time the board, if I use OpenOCD tools, I can erase sometime but with different time for sector 1  sometime 1 second and sometime 17 seconds and of course when I read again all byte stay in place. (erase failed) . I am so confuse, it is seems to be work but not always.  Power issue  on my schematic ?  But 3.3V not so bad and 1.2V seems to be ok . 1 mistake maybe VCAP are 4.7uF and not 2.2uF do you think than it can be the cause of my issue ?

And when I succeed to flash correctly, the CPU won't start correctly just 1 time... 

Thank you so much for your help.

Thank you community.

[Julien M]

Posted on August 01, 2017 at 10:11

Finally, I found the issue, the power wires were not properly connected.