USB DFU Error Uploading Option Bytes, and incorrect serial number reported - STM32F746

[sasha]

We have custom hardware with STM32F746, and having issues getting factory bootloader DFU USB working. When I run STM32_Programmer_CLI -l usb command, I can see my device (although Serial Number looks wrong).

When I try to connect with STM32CubeBootloader (tried V2.1 and V2.2), I get the following errors:

16:19:53:063 : Error: Uploading Option Bytes bank: 0 failed

16:19:53:091 : Error: Initializing the Option Bytes failed

My board has a 24MHz external crystal.

Does anyone know what the issue might be?

I think the correct drivers are installed.

[Nesrine.JLASSI]

Hello @sasha​ 

Try to repeat the same scenario with the latest version of CubeProgrammer . I just tested it now and did not have any problems.

Best regards,

Nesrine

[sasha]

Hi, I am still having issues with this. I have tried with version 2.3.0 of STM32CubeProgrammer and it has the same issue - I can connect via USB, it reports the correct Device ID and FW version, but has an incorrect Serial Number & fails to upload option bytes.

We have two hardware configuration which both have the same issue: One is clocked with 24MHz crystal, and one with 25MHz External Oscillator.

I have also tried this on two different computers - same issue.

What could be the issue?

[sasha]

Hi again, does anyone know what happens if the internal bootloader mis-calculates the HSE frequency? I'm wondering if this could cause the issue I'm seeing.

Sometimes my custom PCB will work with Dfu, and sometimes it will not - it does connect, but then fails when reading the option bytes as described above. I have tested 10 different pieces if PCB - one day all of them worked with DFU, another day only 1 of them worked.

I see in the App Note it mentions that if the HSI calibration is out by 1% it can miscalculate and HSE value and that DFU might "dysfunction or not work at all". We are testing at 25degC.

Is DFU stable with 25MHz HSE clock (oscillator)? Has anyone had experience with this?

[SJULI.1]

Hi Sasha, Did you find a solution? I have the problem...

[HTitalia]

Hi Sasha and SJuli

did you solved your problem? I just got the error and don't know how to solve it..

Thanks.