Embedded J-Link into nRF53840 DK for programming nRF52832

[Domenico]

Hi,

my board is configured for working @1V8 so I do expect that nRF52832 OB J-Link doesn't work for programming it due to the fact that DK can work @3 / 3.3V only.

I'm gonna buying a nRF53840-DK for a future design an I just read that in a particular configuration OB can use VDD_nRF that should be FW configurable.

There are no detailed description of that procedure, can someone guide me through it in order to program my nRF52832 @1V8 using the J-Link OB embedded into nRF53840-DK ?

Thank you in advance

Domenico

[Susheel Nuguru]

Thanks for your patience. All the possible configuration as documented in the DK userguide. If check this and let me know if you think some info is missing.

[Domenico]

How can I configure the SOC to reduce VDD_nRF down to 1V8?

[Susheel Nuguru]

I can't find anywhere on how to do that. That documentation about being able to configure the VDD_nRF is confusing. 

I just read that in a particular configuration OB can use VDD_nRF that should be FW configurable.

Where did you read this?  Maybe I can try to investigate the source of that documentation that you read?

[Domenico]

Pag. 26 of the DK Userguide you are referring:

so how can I configure VDD (Aka VDD_nRF via nRF5340 FW) ?

Thank you

[Susheel Nuguru]

I am not sure what is the meaning of "VDD can be set from nRF5340 firmware" means here. The best I can think of selecting the regulators within the nRF5340 using the firmware running inside it.

You should be able to use BREGHVOUT which is 1.8v by defailt at nrF USB port.

• Connect a usb to both J2 and NRF_USB
• Switch from "VDD POWER" to "USB SOURCE" on SW9
• Power up the DK
• Enjoy 1.8V debugging