Difference between nominal and data bit time FDCAN parameters
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
‎2024-03-26 8:21 AM
Hello,
I am developing a CAN bus application.
I am new to the FDCAN peripheral and I haven't understood the difference between nominal bit time parameters and data bit time parameters.
Which of these two groups of parameters should I configure to obtain the desired baud-rate and sample point?
Regards,
Carlo
Solved! Go to Solution.
- Labels:
-
STM32H5 Series
Accepted Solutions
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
‎2024-03-26 8:37 AM
It depends on what mode you configured for your FDCAN peripheral.
Did you configure it in Classical mode? i.e. CAN2.0 of CANFD?
For Classical CAN, only Nominal bit time is taken the data bit time is discarded.
For CANFD configuration, you can have tow bitrates on a CAN frame: bitrate for the arbitration phase and another bitrate for the data phase.
refer to this link.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
‎2024-03-26 8:37 AM
It depends on what mode you configured for your FDCAN peripheral.
Did you configure it in Classical mode? i.e. CAN2.0 of CANFD?
For Classical CAN, only Nominal bit time is taken the data bit time is discarded.
For CANFD configuration, you can have tow bitrates on a CAN frame: bitrate for the arbitration phase and another bitrate for the data phase.
refer to this link.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
‎2024-03-26 8:49 AM
Thank you very much.
Yes, have configured the peripheral in classical mode.
So I just have to configure the nominal bit time parameters, while leaving the data bit time parameters at their default values. Isn't it?
I have always worked with CAN 2.0A, and I don't know the FDCAN extended features.
Regards,
Carlo
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
‎2024-03-26 8:54 AM
Yes, have configured the peripheral in classical mode.
So I just have to configure the nominal bit time parameters, while leaving the data bit time parameters at their default values. Isn't it?
Yes it is. keep them at default values. They are discarded by the CAN cell.
I have always worked with CAN 2.0A, and I don't know the FDCAN extended features.
It's time to start ;)
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
‎2024-03-26 9:04 AM
It's time to start ;)
Yes you are right! :grinning_face_with_sweat:
