We are unable to connect the nRF54L15 DK Debug Out port to our external nRF54L15 pre-production board. Error: code: 1, description: Generic, message: Batch task protection-get failed, Device error: Setting the debug port SELECT register failed

[Steve]

We have the Nordic nRF54L15-DK PCA10156 0.9.3 2025.19

We use nRF Connect for Desktop v5.2.1 and Programmer v4.7.2 and connect by USB to our ASI_nRF54L_DK1 001057739416.

Windows OS: Windows 11 Pro v 25H2 build 26200.7623

PC Hardware: Intel Core i7-8700 3.2GHz  16GB RAM  64-bit OS, x64 processor

The Programmer Logs the following initialization:

14:19:58.371

Initialising the bundled nrfutil device

14:19:59.280

Using the bundled core version for nrfutil device: 8.1.1

14:19:59.307

Using nrfutil device version: 2.15.7

14:19:59.308

Using nrf-device-lib version: 0.22.5

14:19:59.308

Using nrf-probe version: 0.51.0

14:19:59.308

Using SEGGER J-Link version: JLink_V8.76

14:19:59.325

Getting serial port options from the persistent store for AH02X0KT.pc-nrfconnect-programmer

14:19:59.326

Device connected with the serial number AH02X0KT

14:21:06.589

Getting serial port options from the persistent store for 001057739416.pc-nrfconnect-programmer

14:21:06.589

Device connected with the serial number 001057739416

14:21:06.613

Getting serial port options from the persistent store for 001057739416.pc-nrfconnect-programmer

The setup works fine for programming the DK's BLE chip.

We are following the instructions from the nRF54L15_DK_HW__USER_Guide_v0.9.1.pdf for programming an external board, but always get this error:

12:33:34.446 Failed "reading readback protection status for application core". Error: code: 1, description: Generic, message: Batch task protection-get failed, Device error: Setting the debug port SELECT register failed while powering up sys and debug regions (Unknown error in the J-Link DLL (error code =-1)). This might indicate that the debug port is unavailable. Double-check device power supply and SWD lines, and ensure that SWD is not disabled
12:33:58.273

These are our Connections from P19 DEBUG_OUT to our external board:

• Power Supply 2.5V to SWDO_VTG and to our board's BLE VDD.
• GND to Ground
• SWDO_SWDIO to SWDIO
• SWDO_SELECT to Ground
• SWDO_SWDCLK to SWDCLK
• SWD0_SW0  Not Used
• SWDO_RESET  Not Used

Is the RESET connection required now? Because on nRF52 devices, Reset would break the programming. What must we do to enable the SWD? What J-LINK Settings should we use on the Programmer GUI?

[Steve]

Thanks to all who replied with hints to a solution. The answer for nrf54 devices is to forget about nrfjprog which is unsupported and depricated. The new programmer is nrfutil but this beast takes an AI to help you figure out what to do with it.

First, go to  One tool to rule them all: nRF Util becomes a unified command line utility to learn how to set it up.

I found that the command completion icing still does not work reliably.

The new command line for programming at a new clock speed is:

> nrfutil device program --firmware app.hex --swd-clock-frequency 1000 --options chip_erase_mode=ERASE_ALL --reset-kind RESET_SYSTEM

You may still need the nRF Connect and Programmer apps to connect with the right device, and there's no command line entry there so you need a Windows PowerShell (if that is your platform) to enter the line.

This is all the worst kind of clunky first time out sophomoric user interface, but looks like it  works.