External J-LINK to flash nRF52840 DK chip

I am currently using a J-LINK EDU Mini to try and learn how to use an external device to flash the nrf board. I am running into trouble because I have connected my external J-LINK to my debug-in pins on the board, but segger embedded studio/ J-LINK commander are both having a problem connecting to the target. What am I doing wrong?

         

  • I've tried to replicate your setup, but I have not been able to reproduce the issue. Just to confirm, I assume you are able to program the nRF52840 with the on-board debugger?

    My setup:

    J-Link Commander:

  • Interesting. Yes, I have been able to use the on-board debugger for some time now. This was just a recent thing that I have been trying to learn how to use the external debugger.

    There would not be a driver or anything that I may be missing?

  • I decided to flip the way the wire was connected to the jlink and got this error message instead.

    Preparing target for download
    Executing Reset script TargetInterface.resetAndStop()
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via AIRCR.SYSRESETREQ.
    Reset: SYSRESETREQ has confused core.
    Failed to power up DAP
    Reset: Using fallback: VECTRESET.
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via AIRCR.VECTRESET.
    Reset: VECTRESET has confused core.
    Reset: Using fallback: Reset pin.
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via reset pin
    Reset: VC_CORERESET did not halt CPU. (Debug logic also reset by reset pin?).
    Reset: Reconnecting and manually halting CPU.
    Failed to power up DAP
    CPU could not be halted
    Reset: Core did not halt after reset, trying to disable WDT.
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via reset pin
    Reset: VC_CORERESET did not halt CPU. (Debug logic also reset by reset pin?).
    Reset: Reconnecting and manually halting CPU.
    Failed to power up DAP
    CPU could not be halted
    Reset: Failed. Toggling reset pin and trying reset strategy again.
    Failed to power up DAP
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via AIRCR.SYSRESETREQ.
    Reset: SYSRESETREQ has confused core.
    Failed to power up DAP
    Reset: Using fallback: VECTRESET.
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via AIRCR.VECTRESET.
    Reset: VECTRESET has confused core.
    Reset: Using fallback: Reset pin.
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via reset pin
    Reset: VC_CORERESET did not halt CPU. (Debug logic also reset by reset pin?).
    Reset: Reconnecting and manually halting CPU.
    Failed to power up DAP
    CPU could not be halted
    Reset: Core did not halt after reset, trying to disable WDT.
    Reset: Halt core after reset via DEMCR.VC_CORERESET.
    Reset: Reset device via reset pin
    Reset: VC_CORERESET did not halt CPU. (Debug logic also reset by reset pin?).
    Reset: Reconnecting and manually halting CPU.
    Failed to power up DAP
    CPU could not be halted
    CPU could not be halted
    Failed to halt CPU.
    CPU could not be halted
    

  • Sorry for the spam, I was just updating with each step I found. It works now. Just flipping the way the wire was attached on the J-LINK device was the cause

  • Glad to hear you found the problem and thanks for the update. I hadn't thought of this. The connector on the DK has a slot to prevent incorrect orientation, but it sounds like the connector on the J-Link didn't have that. 

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