topic Busoff interrupt lost when S32K118 at high load in S32K

Busoff interrupt lost when S32K118 at high load

chenwilsoft — Thu, 09 Mar 2023 02:14:11 GMT

The test case is shorting CANH & CANL repeatedly.

If the load of S32K118 is low, the recovery strategy works fine.

Step1. Busoff raised interrupt & set a flag. Step2. In the main loop, if the flag is set, DeInit & Init CAN. Step 3. wait 100ms. Step 4. Send a frame of data. Step 5. Busoff raised again.

But when the load is high ( ADC interrupt raised every 10ms ), there is a different symptom that occurs in a very low probability. The beginning 4 steps are the same.

Step1. Busoff raised interrupt & set a flag. Step2. In the main loop, if the flag is set, DeInit & Init CAN. Step 3. wait 100ms. Step 4. Send a frame of data.

But in step 5, Busoff interrupt is not raised. Instead, Busoff Done Int ( Bit 19 of ESR1) is set and FLTCONF of ESR1 changed from 0x00 to 0x11, which means busoff status.

I don't know why the status of CAN has been changed to BusOff. But the BufOff Int Flag ( bit 2 of ESR1 ) is not set. Instead, Busoff Done Int is set.

Re: Busoff interrupt lost when S32K118 at high load

PetrS — Thu, 09 Mar 2023 14:35:05 GMT

Hi,

could you please specify the code/driver you are using and its version (SDK, RTD,...)?
If using SDK/RTD do you use callbacks to indicate ISR hit?
How do you check flag setting in the main?
If you increase priority of FlexCAN interrupts, do you see the same?

BR, Petr

Re: Busoff interrupt lost when S32K118 at high load

chenwilsoft — Mon, 13 Mar 2023 03:12:20 GMT

The version of IDE is S32DS 2008 R1，update11, using SDK version 3.0.0.

The callback function judges the flag of ESR1 and sets a variable to 1. In the main loop, judge the variable. If it becomes 1, trigger functions and reset the variable to 0.

Increasing the priority of FlexCAN is under testing.