nRF5840 custom board won't boot on power on.

[mark.spanberg]

I have a custom board based on QIAA Reference Layout 1.1 Variant 6.

The application is built with Zephyr without bootloader and is placed directly on address 0x0.

When I compile the application for the nRF52840 USB-stick and run it on that board everything works as it should.

When I compile it for my board it will run after programming but when I power cycle the board nothing happens.

If i connect to the board with GDB over SWD and issue "monitor reset" and then "continue" it will however start and run as it should.

Any ideas?

[mark.spanberg]

Ok, so there might have been a "CONFIG_BOARD_ENABLE_DCDC=y" that shouldn't be there in one of the millions of Zephyr config files.

[Susheel Nuguru]

Enabling the DCDC is normally when you are using peripherals that draw high current like RADIO.

Just enabling the DCDC should not be the main reason for the behavior you are looking at.

But does disabling the DCDC fix the problem for you? Can you give me more details on the power source that is connected to your board? 

[mark.spanberg]

I don't have the DCDC-coil on my board (nRF52840 QIAA Reference Layout 1.1 Variant 6) so I guess enabling it could cause some trouble. Anyway it did solve the problem on my design.