nRF54LM20 DK PCA10184 Rev. 0.7.0: PC-controlled power-cycle through Board Controller / nPM1300

[unknown012345678]

Hi Nordic Support,

We are using an nRF54LM20 DK, PCA10184 hardware revision 0.7.0, for automated side-channel analysis (SCA) testing.

Our requirement is to repeatedly perform this sequence from a Windows PC:

Remove power from the nRF54LM20 target → keep it unpowered for approximately 100 ms → restore power automatically → wait for debug/serial communication to recover → start the next test.

Our distributor’s FAE has explained that Board Configurator can adjust nPM1300 VOUT2. We would like to clarify the supported method for actual power-off and automatic power restoration.

1. Does the Board Controller firmware for PCA10184 Rev. 0.7.0 expose a PC-callable power-cycle command or VOUT disable/enable commands? Please provide an exact nrfutil command, API example, or Board Controller protocol/opcode, together with the required tool and firmware versions.

2. Can the onboard nRF5340 Board Controller trigger nPM1300 TASKSWRESET, or provide raw PMIC register read/write passthrough? We are considering I²C address 0x6B, register 0x0001, value 0x01. Please confirm whether this operation is accessible through the supported interface and what it does on this specific board.

3. During the supported operation, what happens to VOUT1 and VOUT2? Which parts of the board lose power or restart? Does J-Link / Virtual COM Port disconnect and re-enumerate, and are the configured output voltages retained?

4. Is the power-off interval configurable? Approximately 100 ms is our desired interval, not a confirmed capability. If it cannot be configured, what interval should we expect?

5. Is there an official script or example for repeated power-cycling and automatic reconnection? If this is not supported by the existing Board Controller, what alternative setup does Nordic recommend?

We require actual removal and restoration of target power. Voltage adjustment or a CPU reset alone does not meet this requirement. Once a supported method is identified, we will verify the supply waveforms, cold boot, possible back-powering through connected interfaces, and reliability over repeated cycles.

Thank you.

[Kenneth]

Hello,

In theory a lot can be done with the right software, but the DK and board configurator does not provide any api or driver to allow it to control it the way you describe. It's simply a GUI that allow you for instance to configure the following for the nRF54LM20:

If you want to do what you want to do, then I see two options, either (1) for instance get a USB swithchable hub that you can control from a command line (e.g. https://www.yepkit.com/products/ykush), alternatively (2) the nRF54LM20-DK do have a nRF Current Measure header where you can apply an external power source, you can turn off an on the nRF54LM20 as you want using this header, you can even use a second nRF54LM20-DK where you simply control a GPIO that control a small relay that is attached to the nRF Current Measure header of the first DK, with the help of Claude it should be fairly easy to setup a small project where you can control a GPIO over a serial interface.

Btw: please get yourself a new nRF54LM20-DK (v1.0.0 or newer), the DK you have (v0.7.0) have early engineering silicon that is not going to production.

Kenneth

[unknown012345678]

Hi Kenneth,

Thank you for the clarification and the practical suggestions.

We understand that the DK and Board Configurator do not provide an API or driver for the automated power-cycle sequence we described. We will evaluate the two external control options you suggested: a command-line-controlled USB hub, and switching an external supply through the nRF Current Measure header.

Thank you also for pointing out that our Rev. 0.7.0 DK contains early engineering silicon. We will arrange to obtain a Rev. 1.0.0 or newer DK for further testing.

Your explanation has helped us clarify the next steps. Thank you for your support.

Best regards,
David

[unknown012345678]

Hi Kenneth,

Thank you for your explanation and the suggested alternatives. We understand that the current Board Configurator does not provide an API for the automated power-cycle operation we need.

Before adding external switching hardware, we would appreciate your advice on whether there might be another way to use the existing onboard nRF5340 and nPM1300—for example, a Board Controller command, a PMIC register-access interface, or a supported J-Link script.

If this would require additional firmware support, would it be possible to forward our request to the relevant team for consideration? A PC-controlled power-cycle function would be helpful for our repeated SCA measurements.

We need actual removal and restoration of the target supply, rather than a CPU reset. We also plan to follow your recommendation to use a Rev. 1.0.0 or newer DK.

If external switching remains the recommended approach, we understand and appreciate your guidance.

Best regards,
David

[Kenneth]

We’d love to help, but there are a lot of other tasks ongoing with higher priority, so I don't see that we can meet this request.

Kenneth

[unknown012345678]

Hi Kenneth,

Thank you for checking and letting us know. We understand the current priorities and appreciate your time and guidance.

We will proceed with evaluating the external power-switching options you suggested.

Best regards,
David