Unexpected CAN Baud Rate Discrepancy on Verdin iMX8MM

Technical Support
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1

Hello,

During development, I found that the actual baud rate of CAN on a Verdin iMX8MM is half of what is being set with IP command. It took me quite some time to figure this out I am posting this in the hope that some of you can give it a quick try and if my finding is correct you guys can at least document this.

How to reproduce:

  1. Take a Verdin iMX8M Mini Quad (with CAN)
  2. Install BSP 5.7 LTS, BSP 6.3.0 (upstream or downstream) or Torizon 6.3.0
  3. sudo ip link set can0 up type can bitrate 100000 restart-ms 1000
  4. candump can0 and or cansend can0 069#DEADBEEF
  5. The measured baud rate is not as expected 100 kbps it is 50 kbps

I measured the baud rate with an oscilloscope and I tested it against two independent CAN-bus partners

  • Ixxat USB-to-CAN v2 (setup at 50 kbps)
  • My uC-based CAN-Device that runs at 50 kbps

As mentioned above I reproduced this with:

  • BSP 5.7 LTS
  • BSP 6.3.0 Quarterly upstream and downstream
  • Torizon 6.3.0

Cheers,
Philippe

3

Hello @philschenker ,
The issue that you are experiencing might be related to some changes mentioned here.

You can try flashing an older BSP version (e.g. 5.6.0+build.18 ) and check if it works.

Please let us know the outcome.

Best regards,
Josep

5

Very interesting! Thanks for your answer, that makes sense - thanks for pointing this out I didn’t notice it in the release notes!

Best Regards,
Philippe

6

Hello @philschenker , thanks for the feedback :slight_smile:
If that solved the problem, could you please the most suitable answer as solution?

Best regards,
Josep