topic Re: FlexCAN BautRate setting of S32R274 in MPC5xxx

FlexCAN BautRate setting of S32R274

Durant-Harden-Irving — Tue, 09 Mar 2021 17:21:25 GMT

Hello,

Sorry to trouble you!

My question is:

1. The FlexCAN bautRate can be calculate as below, am I right? (Using 40M OSC clock)

BautRate = 40M / (PRESDIV + 1) X (PROPSEG + PSEG1 + PSEG2 + 4)

2. How to determine the value of PROPSEG / PSEG1 / PSEG2 / RJW? Which value is recommend or perfect for S32R274?

Thanks!

Re: FlexCAN BautRate setting of S32R274

PetrS — Tue, 09 Mar 2021 20:47:02 GMT

Hi,

1) yes, the bitrate for standard CAN is calculated that way and parameters are set in CTRL1 register. For CAN FD the CBT and FDCBT should be used to define bitrate for nominal and data phases.

2) you can try to use this tool https://community.nxp.com/t5/MPC5xxx-Knowledge-Base/MPC5xxx-S32Kxx-CAN-CAN-FD-bit-timing-calculation/ta-p/1119319
S32R274 is not listed there, but you can use e.g. MPC5748G, it has the same registers.

BR, Petr

Re: FlexCAN BautRate setting of S32R274

Durant-Harden-Irving — Wed, 10 Mar 2021 02:36:20 GMT

Thanks very much!

Re: FlexCAN BautRate setting of S32R274

Durant-Harden-Irving — Wed, 10 Mar 2021 03:01:13 GMT

The tool is very helpful，Thanks！