I'm trying to troubleshoot an issue with the TM4C1290NCPDT microcontroller.
Our device outputs messages when in certain modes. In normal operation we have a mode which outputs no messages and another mode which puts messages out at 100Hz. Modes are switched via CAN messages but in the situations I'm looking at there are no CAN messages on the bus that would direct the unit to switch modes. It appears there may be something external triggering the condition but the message transmission drought ALWAYS lasts for 3.01 seconds.
We have had situations occur where multiple units are putting out messages at 100 Hz as usual and then something occurs to cause all of the units to cease outputting messages simultaneously. Again all for exactly 3.01 seconds. We've also captured numerous occurrences of single units on the bus exhibiting this behavior.
We are running the processor at 120 MHz and the CAN baud rate is 250 kbps. I'm interested in finding out what mechanisms are in the microcontroller that would cause this to occur. As far as I can tell no CAN message(s) are received to instruct the microcontroller to switch the output mode or to disable the CAN transmission when this occurs.
Based on the fact that we have seen multiple devices experience this phenomena at the same time, the event seems to be triggered externally perhaps by an RF field, low voltage condition, brownout condition or something of that nature. What mechanisms are there that might cause this? That is, what mechanisms in the microprocessor might cause it to stop transmitting the messages for precisely a 3.01 second period?
Thank you in advance for your time and effort in this regard.
