Using the J-link OB on nRF52840-DK to program nRF54L15

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

Pavanreddy0 — Thu, 02 Apr 2026 10:59:30 GMT

Hi,

Thanks for the clarification.

I checked the information about nRF52840 DK versions supporting Cortex-M33 devices.

In my case, I am using an nRF52840 DK, but I am facing the following behavior:

The debugger detects the nRF54L15 over SWD
I am able to read the device ID
However, flashing fails (erase/write does not work)

Could you please help clarify:

Does the J-Link OB on nRF52840 DK fully support flashing (erase/write) for nRF54L15, or is the support limited?
Are there any specific requirements such as:
- Minimum DK version (v3.0.0 or later)?
- Required J-Link firmware version?
- Required nRF Connect SDK / tools version?
Is there any known limitation when using J-Link OB with nRF54L15 RRAM?

I want to confirm whether this setup is officially supported for programming, or if using an nRF54L15 DK / external J-Link is recommended.

Thanks!

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

k.leonhardt — Tue, 12 Aug 2025 11:41:23 GMT

Just to be sure before buying more stuff.

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

Håkon Alseth — Tue, 12 Aug 2025 10:44:04 GMT

Happy to help out, Kasper.

Was the issue related to the DK version?

Kind regards,

Håkon

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

k.leonhardt — Tue, 12 Aug 2025 09:05:29 GMT

Hi Håkon

Thank you for precise explanation.

Regards

Kasper

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

Håkon Alseth — Mon, 11 Aug 2025 07:49:52 GMT

Hi,

Which version of the nRF52840-DK do you have?

v3.0.0 and newer can program Cortex M33 based nRF's (nRF53, nRF91, nRF54)

v2.x.x can only program up to Cortex M4 based devices (nRF51-series, and nRF52-series).

Kind reghards,

Håkon

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

frogrammer — Sun, 10 Aug 2025 15:28:35 GMT

Hey my bad, actually the datasheet says with nRF54L15 DK you can program boards with other series nrf5 series.

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

k.leonhardt — Sun, 10 Aug 2025 15:28:01 GMT

Did you see in my post, that I did not want to use the nRF54L15DK but the nRF52840-DK?

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

k.leonhardt — Sun, 10 Aug 2025 15:23:31 GMT

Thanks.

RE: Using the J-link OB on nRF52840-DK to program nRF54L15

frogrammer — Sun, 10 Aug 2025 15:21:21 GMT

Yes you can , see datasheet page 20 of nRF54L15DK hardware.

for Programming setup other than the debug out cable , i use from DK P20 output

(nRF_VDD+ VTG ) ------ target_VDD

GND ------target_GND

SWDIO ------target_SWDIO

SWDCLK ------target_SWDCLK

SWO ------target_SWO

nRESET ------target_nRESET

Putting nRF_VDD and VTG together will make your DK to target custom board and provide power as well.