[SOLVED] VCOM enable/disable issues with J-Link OB SAM3U

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  • [SOLVED] VCOM enable/disable issues with J-Link OB SAM3U

    Hi,

    I am trying to debug an application we are using in production which programs and tests development kits with the J-Link OB, and have run into the following issue:

    - The software calls the JLink programming application and downloads firmware (the OB license is pretty old, the fw sting is J-Link OB-SAM3U128 V1 compiled Aug 27 2013 15:22:27 - I believe it came with Jlink v4.79b). The VCOM is enabled in this fw.
    - The production application then updates the firmware to a newer version (6.22a) and the VCOM disappears (this also happens when updating to any intermediate version from JLink v4.98 onwards).

    Since the VCOM is needed for subsequent tests, it must get re-enabled. This is all handled by the test app (in Labview, but can call external .dlls or .exes) and should be done preferably without any popups to the operator.

    So, is there a way to re-enable programmatically the VCOM or prevent it from disappearing in the first place before updating?
    The only workaround I see is calling Jlink.exe and running the "vcom enable" command as described in your Wiki, but it's a bit cumbersome. Isn't there any other more direct way? Like a call to JLinkARM.dll, or some command string?

    Thanks for your time :)
    Kostas
  • Hello Kostas,

    Thank you for your inquiry.

    To enable VCOM permanently you can also use the J-Link Configurator.
    You can simply open the J-Link Configurator, double click your device and enable VCOM, then power the J-Link off and on and press ok.
    Now the VCOM setting should be memorized even after a power on reset.

    Does that solve the issue?

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.
  • Hi Nino,

    Thanks for your reply.

    I am aware of this option too, but since this software runs in production in "batch" mode, there should be no popups/no extra action needed from the operator.

    I finally got around this by writing the EMU's configuration area directly, and it now works.

    Regarding these config bytes, I see that enabling/disabling the VCOM changes a different set of config bytes depending on which version of Jlink Configurator you are using.
    Is there any sort of table of what each config byte does, or this is not public info?

    Thanks again :)

    Best regards,
    Kostas
  • Hi Kostas,

    What board are you using and what target device are you trying to program with your OB?
    We will then investigate why VCOM was even disabled if this was originally part of the OB FW.

    Is there any sort of table of what each config byte does, or this is not public info?

    This is not public info as the user should never have to care what is written in there.

    Regarding these config bytes, I see that enabling/disabling the VCOM changes a different set of config bytes depending on which version of Jlink Configurator you are using.

    Can you give an example which version does what?

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.
  • Hi Kostas,

    I have contacted you per email in this regard.
    This thread will be closed now.

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.