CCS/TM4C123GH6PM: It jumps to ResetISR

The images you added did not show up. I use "snip" to grab a screen image, then save it as a ".png" file. Then I use this icon from the tool bar to insert the picture.

Thanks, Bob

It's helpful and I insert the picture successfully.

The issue happens when it runs into USBDCDCInit. FaultISR is run when it steps into GPIOPinWrite.

I haven't modified any code. It is ok after I removed usbdcdc.c file from my project.

Normally I would say that you executed a fault because you tried to write to GPIO port F without enabling the clock to that port. However, I don't see why calling USBDCDCCompositeInit() would have any impact. With a breakpoint on the GPIOPinWrite() on line 2435 look at the GPIO F registers in the CCS register window to verify that they can be read. Can you export your project to a .zip file and attach it to this thread?

Thanks, Bob

Enclosed is my project .zip file. I'm debugging the usb_dev_serial project.

The project can run well if I remove the usbdcdc.c file.

So, I stepped into the file and came to USBDCDCInit() -> GPIOPinWrite().0636.usb_dev_serial.zip

In this thread you selected part number TM4C123GH6PM. This is the part on the EK-TM4C123GXL LaunchPad. In line 714 of your C file "usb_dev_serial.c" you enable GPIOL. The TM4C123GH6PM part does not have GPIOL. What part/board are you actually using?

Hi, Bob

Sorry for my mistakes. Thank you for pointing it out.

The part number is EK-TM4C123GXL LaunchPad.