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TMS320F280025: Unable to communicate with the device

Steven Shenker
Intellectual 800 points
Part Number: TMS320F280025

Hi there, 

I have two prototype boards made with this TI micro and am unable to connect to this device using the XDS100V3 debugger. I get the message: "The JTAG IR and DR scan-paths cannot circulate bits, they may be broken."

I am unsure whether my boards are functioning properly as with one of them VDD seems to gradually drop below 1.2V until it hits 0.8V. XRSn reset pin is measured at 3.3V which looks right.

On the other board VDD is stable at around 1.2V but the XRSn reset pin seems to be pulling itself down to a constant 0.5V (I read somewhere this device can drive this pin low in the event of an internal issue). 

See my circuit below, the only difference I see between the recommended layout is I do not have a capacitor between VREFHI and VREFLO as I am not using the ADC. 

I have set the boot mode to SCI / Wait Boot which I assume is correct for flashing/debugging?

Another thing that comes to mind is that this JTAG 14-pin interface recommends leaving the TRST pin unconnected on the header as per the below. I wonder if the XDS100V3 is not happy with this lack of ground/VCC on this pin?


 I get the same message trying to flash either board. The 3.3V supplies look fine when measured. I am not sure how to solve this issue and any input would be appreciated.

Thanks in advance for your help.

  • 0
    Intellectual 800 points

    Complete error message below:

    [Start: Texas Instruments XDS100v3 USB Debug Probe_0]

    Execute the command:

    %ccs_base%/common/uscif/dbgjtag -f %boarddatafile% -rv -o -F inform,logfile=yes -S pathlength -S integrity

    [Result]


    -----[Print the board config pathname(s)]------------------------------------

    C:\Users\Steven\AppData\Local\TEXASI~1\CCS\
    ccs1120\0\0\BrdDat\testBoard.dat

    -----[Print the reset-command software log-file]-----------------------------

    This utility has selected a 100/110/510 class product.
    This utility will load the adapter 'jioserdesusbv3.dll'.
    The library build date was 'Mar 17 2022'.
    The library build time was '15:43:48'.
    The library package version is '9.7.0.00213'.
    The library component version is '35.35.0.0'.
    The controller does not use a programmable FPGA.
    The controller has a version number of '4' (0x00000004).
    The controller has an insertion length of '0' (0x00000000).
    This utility will attempt to reset the controller.
    This utility has successfully reset the controller.

    -----[Print the reset-command hardware log-file]-----------------------------

    The scan-path will be reset by toggling the JTAG TRST signal.
    The controller is the FTDI FT2232 with USB interface.
    The link from controller to target is direct (without cable).
    The software is configured for FTDI FT2232 features.
    The controller cannot monitor the value on the EMU[0] pin.
    The controller cannot monitor the value on the EMU[1] pin.
    The controller cannot control the timing on output pins.
    The controller cannot control the timing on input pins.
    The scan-path link-delay has been set to exactly '0' (0x0000).

    An error occurred while hard opening the controller.

    -----[An error has occurred and this utility has aborted]--------------------

    This error is generated by TI's USCIF driver or utilities.

    The value is '-233' (0xffffff17).
    The title is 'SC_ERR_PATH_BROKEN'.

    The explanation is:
    The JTAG IR and DR scan-paths cannot circulate bits, they may be broken.
    An attempt to scan the JTAG scan-path has failed.
    The target's JTAG scan-path appears to be broken
    with a stuck-at-ones or stuck-at-zero fault.

    [End: Texas Instruments XDS100v3 USB Debug Probe_0]

  • 0 in reply to Steven Shenker
    TI__Guru 50430 points

    We have US holiday on Monday. We will get back to you on Tuesday.

  • 0 in reply to Santosh Jha
    Intellectual 800 points

    Thank you. FWIW this is my XDS100V3 configuration. I scoped the signals and I noticed the TDO signal is not changing so the micro is not happy. Would prefer not to try and replace the f280025 ICs if there is something else I can try - especially since both prototypes are not working/have same error behaviour.

  • 0 in reply to Steven Shenker
    TI__Guru 50430 points

    Steven,

    The subject matter expert will get back to you tomorrow. Sincere apology for late response.

    Thanks & Regards,

    Santosh

  • 0 in reply to Santosh Jha
    TI__Mastermind 25321 points
    Steven Shenker said:
    I have two prototype boards made with this TI micro and am unable to connect to this device using the XDS100V3 debugger. I get the message: "The JTAG IR and DR scan-paths cannot circulate bits, they may be broken."

    I would recommend switching to an XDS110 debug probe if possible: https://www.ti.com/tool/TMDSEMU110-U. 

    Regarding the XDS100v3, there is this note here. Can you try the cJTAG setting to see if this works?

    Steven Shenker said:

    I am unsure whether my boards are functioning properly as with one of them VDD seems to gradually drop below 1.2V until it hits 0.8V. XRSn reset pin is measured at 3.3V which looks right.

    On the other board VDD is stable at around 1.2V but the XRSn reset pin seems to be pulling itself down to a constant 0.5V (I read somewhere this device can drive this pin low in the event of an internal issue). 

    Having VDD drop below 1.2V is problematic as it indicates the internal VREG is not functioning correctly. Maybe double check the MCU pinout in your schematic against the datasheet pinout to make sure there is no error. I would leave the JTAG probe disconnected while checking basics like power, reset, and clock.