Exact allocation between propagation segment and phase segment 1

BBute.1 · ‎2025-06-20

Hello,

I am considering to use several STM32 microcontrollers to develop CANFD devices. I just saw CANFD Bosch specification v1.0, and more particularly scope 8 which defines the following requirements:

Unfortunately, on all STM32 I have been confronted so far, you cannot specify exactly PROP seg and Phase seg 1 indivually but just the overall (Prop_seg+Phase_seg1). Which is fine to determine the sample point but I am not able to check if my bit timings are meeting the requirements above as I cannot discriminate prop seg length from phase 1 length.

1. Is the dispatch between propseg and phase seg 1 constant over all devices ?

2. Is the propagation segment always fixed to 1Tq for example ?

Any insight regarding this would be appreciated,

Best regards

mƎALLEm · ‎2025-06-20

Hello,

Hello for FDCAN timing, I propose you to refer to this Youtube video: FDCAN Normal Operating Mode

Kvaser calculator can also help you for CAN-FD bit timing.

Hope that helps.

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