TM4C1231C3PM: forced hard fault

Hi,

  I suppose you do not have any problem (i.e. hard fault) when your MCU is isolated from the motor, correct? I think the problem you have is a board level problem although I don't know what exactly caused it. I will suggest several things to check:

 - Can you confirm if the MCU is cut off from the motor, will it see hard fault?

 - Monitor the power supply to the MCU. Do you see any voltage out of regulation when you tur off the motor? I wonder if the back emf causes the power to drop for the MCU. 

 - Go through this app note to find out the cause of the hard fault. https://www.ti.com/lit/pdf/spma043. Please back trace and find out where in your application caused the hard fault. Is it always the same source when you turn off the motor?

  - Can you repeat the same problem on a different board?

  - Can you repeat the same problem on the LaunchPad?

This issue is not happens with MSP430FR6970 MCU, for upgrade i did PCB using TM4C1231C3 MCU, issue happens with 32 bit mcu only, this factor is confusing for me.

All the power supply ground are same, not isolated from the source.

Hi,

  You have not answered any of my questions. Without some clarity, I don't have any suggestion. The only information I have from you is that back emf caused the device to a hard fault.