topic Re: CAN stop sending data in S32K

CAN stop sending data

tamiritzhaki — Thu, 18 May 2017 12:53:49 GMT

I am using S32K144EVB boards based on S32K144_CAN_MASTER/SLAVE example. I modify the code so the slaves will send periodic data (every ~20mS) on the bus. The problem I have is that every couple of hours one of the slaves stop sending data and it recovers only after reset. The bus configuration set to CAN (not FD) at 100kbps.

I am aware of the Bus Off Recovery bit (BOFFREC) but it already enabled (not sure if its relevant to non FD setup).

Whats the possible options I have to recover the data transmission?

Re: CAN stop sending data

PetrS — Fri, 19 May 2017 08:46:07 GMT

Hi Tamir,

If the issue appears, do you see any error detected, look at ECR, ESR1 registers?

The CTRL1[BOFFREC] defines how the FlexCAN recovers from Bus Off State. If the bit is set, then automatic recovering is disabled. Bus off state is indicated by setting ESR1[BOFFINT], ESR1[FLTCONF] becomes 0b1x. The user have to clear BOFFREC manually so the module can leave Bus Off state.

BR, Petr

Re: CAN stop sending data

tamiritzhaki — Sun, 21 May 2017 14:11:01 GMT

Hi Petr,

The registers value in the time when the issue occurs:

CNTR1 = 0x04610007

ESR1 = 0x00040080

ECR = 0

Can you see reason for this phenomenon?

BR,

Tamir

Re: CAN stop sending data

PetrS — Mon, 22 May 2017 08:36:06 GMT

Hi Tamir,

Those values do not indicate any issue. It says the module is synchronized to the bus and is error active.

If there is any active MB set for the TX or RX operation it should work.

I can recommend to enable the error interrupt and read ESR/ECR once it is called. This way you can find the reason of the errors, if there are any.

If you will have a doubts still, please share your modified SLAVE example so I can test it on the EVB.

BR, Petr

Re: CAN stop sending data

tamiritzhaki — Thu, 25 May 2017 06:45:04 GMT

Thank you Petr, I will check the ESR/ECR once it is called and if needed will share my project.

BR, Tamir