topic Re: S32K144 FlexCAN Stop to Send Messages in S32K

S32K144 FlexCAN Stop to Send Messages

xiaoyuwang — Sun, 07 Oct 2018 02:06:46 GMT

I am using S32K144 FlexCAN module. I met a problem now:

When I debug my source code, I set several break points. Every time when I start to run the SW after it stopped at a break point, then it will stop to send CAN messages. I want to know the root cause and how to avoid this case.

Thank you very much~~

Re: S32K144 FlexCAN Stop to Send Messages

danielmartynek — Mon, 08 Oct 2018 19:48:51 GMT

Hi,
Please see Section 53.5.11.1 RM rev.8 Freeze mode.
“This mode is requested either by the CPU through the assertion of the HALT bit in the CAN_MCR Register or when the chip is put into Debug mode. In both cases it is also necessary that the FRZ bit is asserted in the CAN_MCR Register and the module is not in a low-power mode.”

Freeze Enable is enabled by default MCR[FRZ] = 1.
And it will be disabled if you clear that bit.

Regards,
Daniel

Re: S32K144 FlexCAN Stop to Send Messages

xiaoyuwang — Tue, 09 Oct 2018 05:56:24 GMT

hi Daniel,

I have tried to enable Freeze Mode, it works.

But I met another problem now: My ECU will receive 24 messages from vehicle and 3 messages for transmission. 2 messages are 20ms period(ID: 0x190, 0x191)，the third one is 500ms period(ID: 0x390). Sometimes when I start ECU, message 0x390 cannot be sent, but sometimes it is OK. Do you have any idea about this?

ps: Current BusLoad is 25.9%.

Re: S32K144 FlexCAN Stop to Send Messages

pritampatil — Tue, 20 Nov 2018 13:46:46 GMT

Check for NOSTALL bit.

make it high.

Hope it helps..

Regards,

Pritam.