Possibility to debugging and flashing the 52840 DK while PPK is on top.

[rico]

Is there a possibility to debug and flash the DK while the PPK is connected via the headers? Right now I am taking the PPK off to flash; debuging is not possible.

If not, what is the recommended setup? Using one DK to debug and connect the PPK via External DUT to the DKs external supply? Use a second DK to connect to the PPK?

[Stian Røed Hafskjold]

Hi, there's a switch on the PPK that selects which chip to flash. SW3 (COM). I think maybe the naming is wrong, so that the DK position is the PPK, and EXT is the DK.

You can't debug while using the PPK (PPK on top of the DK), because the PPK uses the debugger on the DK to communicate with the PC.

If you want to debug while using the PPK you will need a separate DK or debugger. You can power the nRF5240 DK through the DUT supply -> external supply on DK. Then on the DK you need to set the VEXT->nRF switch to ON and the SW6 to the nRF ONLY position so that the external supply header is not powering everything else on the DK. You must also have a USB cable connected to the USB port on the DK so that the debugger chip is powered. Otherwise the debugger chip will be powered through the SWD lines and RESET line, which will give a high leakage current.

Anyways, the chip in debug mode has a constant current draw of about 3 mA. So you might not get that much information from measuring the current while debugging.

[rico]

Thanks for the answer.

Stian Røed Hafskjold said:

Anyways, the chip in debug mode has a constant current draw of about 3 mA. So you might not get that much information from measuring the current while debugging.

I think that is fine, since the workflow would be to make some changes,flash&debug them, disconnect the debugger and make a current consumption check.

Is this still true even if __WFI() is called for example?

[Stian Røed Hafskjold]

Yes, even if __WFI() is called, the current consumption will be high in debug mode.