S32K144 CAN sample point configure

[jianguo_li]

1. The figure below shows that the sample point I configured is 80%, the crystal vibration on the board is 20MHz, the baud rate is 500K, and the time share of 20tq, which can be configured successfully.

2. The current problem is: based on the same 20MHz crystal vibration on the board and the baud rate of 500K, the sampling point should be configured to meet the requirements of 75%~83.4%, but the time share is 16tq, and the configuration is not successful.

How to configure it?Thank you very much!

[PetrS]

Hi,

how did you get a 16tq? With 20MHz protocol clock and desired 500kbps you will need either 8, 10 or 20 tq and also 40tq if CBT register is used. The setting of 80% sample point is possible.

You can try to test below tool for CAN bit calculation.

https://community.nxp.com/docs/DOC-342618 

BR, Petr