RE: Questions related to nRF52840 DK on-board debug out header (P19)

Bendik Heiskel — Fri, 01 Nov 2024 13:36:21 GMT

Hi,

[quote user=""]Q1) If I'm using the P19 debug out header, is SWD0_SEL supposed to be connected to GND or 3V0 on the custom board?[/quote]

SWD0_SEL must be connected to GND for the debugger to use the debug out connector.

[quote user=""]Q2) I don't want to power my custom board using the nRF52840 DK while programming/debugging it, is that okay? If so, am I supposed to short SB19 and connect VREF on pin1 which is 3V0 to VIO_REF and leave SB47 open (VDD isn't connected to VREF). I have attached an image below for reference
[/quote]

If your custom board is powered with 3V externally there's not need to modify any of the solder bridges on the nRF52840 DK, as it will by default use 3V for the SWDIO and SWDCLK lines.

[quote user=""]Q3) If SWD0_SEL has to be connected to GND on the custom board, would I also be able to use a J-Link Lite CortexM external debugger since the pinout would be the same. (TDI isn't used in SWD). I just wanna confirm and make sure I understand this properly. I have attached an image of the J-Link's debug header pinout below. [/quote]

Yes, there's no issues using a J-Link external debugger with pin 3(SWD0_SEL on the DK) connected to ground.

Best regards,

Bendik

RE: Questions related to nRF52840 DK on-board debug out header (P19)

PaKa — Wed, 30 Oct 2024 08:24:37 GMT

You can check out the nRF52832 DK user guide as that has the correct wiring setup for the DK you have.