topic In MC9S12X, stop sending the error frames in CAN Bus-Off state in S12 / MagniV Microcontrollers

In MC9S12X, stop sending the error frames in CAN Bus-Off state

Nash_win — Wed, 14 Jan 2015 13:50:19 GMT

Currently I am using the Auto Bus-Off recovery feature of MSCAN of MC9S12X.

However, the problem with this is that when the Bus-Off occurs, due to the auto-recovery, the uC starts sending the error frames continuously in the Bus-Off state.

If i want to stop the Error frames for certain period, how can i do it?

Re: In MC9S12X, stop sending the error frames in CAN Bus-Off state

lama — Tue, 24 Feb 2015 11:41:19 GMT

It looks like you are going into the same error after buss off recovery. If the MCU is in the bus off then it does not sends any frames. A bus-off node is not allowed to have any influence on the bus (e.g. output drivers switched off). It looks like you are facing behavior presented in attached files.

What I would like to suggest you is to abort the messages and fix all mistakes:

if (CAN0TFLG != 0x07)

{

if( !CAN0TFLG_TXE0 )

{ CAN0TARQ_ABTRQ0 = 1; // abort the transmission

while ( ! CAN0TAAK_ABTAK0 ) {}

}

if( !CAN0TFLG_TXE1 )

{ CAN0TARQ_ABTRQ1 = 1; // abort the transmission

while ( ! CAN0TAAK_ABTAK1 ) {}

}

if( !CAN0TFLG_TXE2 )

{ CAN0TARQ_ABTRQ2 = 1; // abort the transmission

while ( ! CAN0TAAK_ABTAK2 ) {}

}

while(CAN0TFLG != 7);

}

Best Regards, Ladislav

Re: In MC9S12X, stop sending the error frames in CAN Bus-Off state

howardg — Thu, 24 May 2018 21:37:04 GMT

Ladislav, do you know whether this technique should fail on the KE06? I tried it, modified for the different register names, but I'm not consistently getting bus-off interrupts with the KE06's MSCAN peripheral. After a bus off interrupt and abort I back off for 5 seconds and then try again. I can do that twice before the KE06/MSCAN gives up and stops generating bus off interrupts.