External J-LINK to flash nRF52840 DK chip

[Lewy2552]

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?

        

[Vidar Berg]

Hello,

I don't see anything wrong with your setup (thank you for including the picture). As a test, could you please set the switch shown in the picture below to the 'nRF Only' position and try again? This will disconnect the on-board debugger from the nRF target.

Best regards,

Vidar

[Lewy2552]

Hello,

Unfortunately it did not seem to do anything rather than turn off the on board LED's. When I ran segger/J-LINK commander, I got the same pop up message. Additionally, I am still getting the pop up message telling me the J-LINK edu mini should only be used for educational purposes. What is reassuring about the pop up message is that I only get that when the nrf is properly powered. Is there any other ideas by chance?

Here are the pop up messages and board:

[Vidar Berg]

I see now that you selected the JTAG interface in J-Link Commander. However, the nRF chip does not have a JTAG interface. Please use SWD instead.

[Lewy2552]

Just tried that, it is giving me the same message on segger and jlink. Tried with both in default mode and nrf only mode

[Vidar Berg]

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:

[Lewy2552]

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?

[Lewy2552]

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

[Lewy2552]

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

[Vidar Berg]

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.