Other Parts Discussed in Thread: SEGGER
Tool/software: Code Composer Studio
I have been running into a puzzling - frustrating problem over the last several months. I'm using a very recent installation of CCS and a Segger JTAG interface that has worked flawlessly on another design.
My board keeps getting into a state where it will repeatably get the error on programming: "CORTEX_M4_0: File Loader: Verification failed: Target failed to write 0x00007FF0", always the same address. The program I'm running is the usbserialdevice_DK_TM4C129X_TI example modified for the very few changes needed for my board, specifically the CPU and how the onboard LED's are connected. My schematic is as close as possible to the DK_TM4C129X board. The 3.3v and 1.2v power rails seem quiet and rock solid (the 3.3v rail is from a linear regulator).
I replaced the CPU and it worked again, for a few times, then the same error again. I thought that maybe I didn't have heavy enough traces to the bypass capacitors on VddC (most close to pin 115). After that it programmed again a few times before failing again. When I probed some JTAG signals (which look good), it started programming again for a little bit. I changed the JTAG clock from "auto" to 1Mb and again it seemed to program reliably for a while.
Now it's failing consistently, if I then download the "Typical SYS-BIOS Example" that will program and run and I can again then run the slightly modified usbserialdevice_DK_TM4C129X_TI example.
I'm flummoxed !! Any thoughts would be appreciated. Thanks.
