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Watchdog is resetting the ECU Continuously when there is no communication on the CAN bus

Question asked by surya phani teja on Sep 19, 2019
Latest reply on Oct 3, 2019 by Diana Batrlova


Dear NXP Support, I am working on S32K146 Controller. I have an issue with Watchdog.
My current watchdog configuration contains below data
WdgMSupervisionCycle: 10ms
WdgMSupervisionReferenceCycle: 10
Total Supervision Reference cycle: 10*10 = 100ms
WdgMExpectedAliveIndications: 10
WdgMMaxMargin: 1
WdgMMinMargin: 1
Min Count of ExpectedAliveIndications: 10-1 = 9
Max Count of ExpectedAliveIndications: 10+1 = 11
This means the WdgM should expect 9, 10 or 11 occurrences within one supervised reference cycle, which is fixed to 100ms (which is 10 WdgM supervision cycle).
I have checkpoint to invoke for every 10ms, then there are 10 or 11 "ExpectedAliveIndications" within 100ms which will satisfy the configuration .
Normal Scenario when there is Issue in the code like Commenting the watchdog checkpoint. In this case, there are 0 Alive_indications in 100ms which will create a watchdog reset (which is working as expected)
1. I am triggering Nm Frames from the canalyzer periodically.
2. Executing the software.
3. Keeping the breakpoint at Application Init Function
4. Able to see the communication with error Frames and Init Function is invoked after everytime reset.
There is another scenario when there is no issue in the code.
In this case, when I am triggering the Nm Frames periodically. watchdog is not resetting the ECU (Didn't observe error frames during communication). But when I stop sending Nm Frames then the watchdog is resetting the ECU continuously.
So, Can you please help me regarding this issue?