NRF52820 Custom board is found by J-Link but seems to hang when starting CPU.

[dslobodzian]

Hello,

I've recently created a custom board based on the NRF52820 which is configured based on the datasheet.

I'm using an NRF52833 DK OB J-Link to program the device. The J-LINK does detect the NRF52820 as well as read the NRF52820 memory which is viewed in the NRF Connect Programmer.

I've tested the board with the example Blinky code but nothing seems to be occurring, I've attached an oscilloscope to a specific pin connected to the MCU and I receive no switching signal.

I've also attempted to use the GDB debugger but it ends up hanging on "Starting target CPU" and if you pause the execution it ends up being stuck on "msr BASEPRI, r0"  which is what I think my problem is.

Does anyone have any potential solutions or is my design incorrect?

[Bendik Heiskel]

Hi,

The blinky example code uses a external 32.768kHz crystal connected to P0.00 and P0.01 as the default LFCLK source. The system will wait until the crystal is started before continuing. Since you are not using a external crystal you will have to switch the source for the LFCLK to the internal RC oscillator.

 

Best regards,

Bendik