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.