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AM2434: In JTAG debugging, how can I connect EMU0 and EMU1?

Part Number: AM2434
Other Parts Discussed in Thread: LP-AM243

Hi Team,

I consulted technical support before designing the board, and he replied that EMU0 and EMU1 would not affect debugging, and it could be suspended or pulled high. Now the board has been made. I used XDS200 and connected it with JTAG, but it cannot be connected at all. My JTAG signals were connected (TCK, TMS, TDI, TDO, TRSTN, RESET). Could you please tell me why this happened?

I think that XDS200 can support AM2434.

Kind regards,

Katherine

  • Hello,

    This is the information about the test. It says that it was not well connected. I don’t know what it meant. I used the multimeter, and the lines were all connected.

    -----[Print the reset-command software log-file]-----------------------------
    
    This utility has selected a 560/2xx-class product.
    This utility will load the program 'xds2xxu.out'.
    The library build date was 'Sep 20 2022'.
    The library build time was '17:17:24'.
    The library package version is '9.9.0.00040'.
    The library component version is '35.35.0.0'.
    The controller does not use a programmable FPGA.
    
    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 '-183' (0xffffff49).
    The title is 'SC_ERR_CTL_CBL_BREAK_FAR'.
    
    The explanation is:
    The controller has detected a cable break far-from itself.
    The user must connect the cable/pod to the target.
    
    [End: Texas Instruments XDS2xx USB Debug Probe_0]

    Regards,

    Katherine

  • Hello Katerine,

    I apologize for the delay but there are a few clarifying questions that I have before I can help you further with your issue.

    1. Could you please provide a block diagram or schematic showing the JTAG signals with the pull resistors? 
    I consulted technical support before designing the board, and he replied that EMU0 and EMU1 would not affect debugging, and it could be suspended or pulled high

            2. Was this in an e2e? If so, could you provide a link? For EMU0 and EMU1, are these signals pulled up?

    I think that XDS200 can support AM2434.

    The XDS200 does support the AM2434. 

           3.Are you able to provide a scope capture of the JTAG signals?

           4.How far away is the AM2434 from the emulator?

    Regards,

    Erik

  • Hello Erik,

    1. When designing it, our hardware engineers directly floated it.

    2. We are the technical support of the consulting agent. It was that it could be pulled up or floated. In the earlier manual, for debugging, there was no detailed information on how to use EMU0/1.

    3. The JTAG waveform was not easy to capture. After I cut off the connection of AM2434 on the board, I lead out the XD110 debugging signal of LP-AM243, making it completely independently. Then I used it on the board designed by us, and everything worked well. However, XDS200, if connected to the same JTAG signal, cannot be debugged, and the test cannot be successful.

    4. When using XDS200 for testing, the distance between the emulator and AM2434 was at most 30CM, and the wire should not be too long. At the same time, I checked XDS200. For the EMU0/1 inside, the signal can be selected. So the floating should be of high impedance, right?

    Kind regards,

    Katherine

  • Hello Katherine,

    This "cable break far-from itself" error means the JTAG debugger is sending data to the device via the TDI pin but is not receiving anything back on the TDO pin.

    Is it possible to probe the TDO signal on the board during the connection test? If you are able to observe data on TDO through probing the board, then you can isolate the cause of the error to either the debug probe or the debug probe connector adapters (if they are being used). 

    Are you able to swap out the debug probe and/or the adapters needed to connect to the board?

    Another possible cause of a "cable break far-from itself" could be that the TVRef signal (pin 5) is pulled up to the IO voltage, or TDIS (pin 4) is pulled-down to ground. TVRef should be connected to the IO voltage through a small current limiting resistor. TDIS should be connected directly to ground. The XDS Target Connection Guide provides additional detail on the connection of emulator signals. 

    Regards,

    Erik

  • Hello Erik,

    Is "Another possible cause of a "cable break far-from itself" could be that the TVRef signal (pin 5) is pulled up to the IO voltage, or TDIS (pin 4) is pulled-down to ground" conflicting with "TDIS should be connected directly to ground"?

    Regards,

    Katherine

  • Hello Katherine,

    TDIS should be connected directly to ground meaning that a 0Ω resistor or direct connection is used rather than using a >0Ω pull-down resistor. 

    Regards,

    Erik

  • Hello Erik,

    I extended the JTAG debugging line of the emulator, and it worked. But I'm afraid if the temperature changes by 0.1 and the resistance changes by 1mo, will problems emerge again?

    Regards,

    Katherine

  • Hello Erik,

    The customer thinks that this is due to the fact that the margin considered in the design of the emulator is too small. Increasing the line's length is equivalent to adding a small resistor. The divided voltage just falls within the recognition range of the emulator. The reference voltage of the IO port and TDIS should be values within a reasonable range. They shouldn't be precise values or fluctuate within a small range. The customer's understanding is that this is owing to the improper design of the emulator.

    Regards,

    Katherine

  • Hello Katherine,

    Are you able to swap out the debug probe and/or the adapters needed to connect to the board?

    Was the customer able to try to connect using a different emulator to rule out that the fault is stemming from the emulator itself?

    Regards,

    Erik

  • Hello Erik,

    The customer replied that he was able to connect using a different emulator and there should be no fault stemming from the emulator itself.

    Regards,

    Katherine

  • Hello Katherine,

    Did they use a second XDS200 to successfully connect or was it a different emulator? 

    Regards,

    Erik

  • Hello Erik,

    I used two simulators, XDS110 and XDS200. XDS110 could be connected directly, and XDS200 needed to be extended to get connected.

    Regards,

    Katherine

  • Hello Katherine,

    I can't speak to the design of the emulator, but I am glad that the customer was able to get both the XDS110 and XDS200 working with the board. Are there any further questions or can I close this thread?

    Regards,

    Erik

  • Hello Erik,

    The customer has no further questions. You could close this thread. Thank you.

    Regards,

    Katherine