J-link OB cannot find nRF52811 on custom board

[bardia3000]

Hello, I'm working on a custom board, and I use JLink OB as programmer. Whenever I try to connect to nRF52811 on the board, this happens:

I check the connections, everything looks fine, Could It be because of the firmware of my Jlink OB?

[bardia3000]

By the way, I checked voltage on all pins, It is a bit strange that P0.21/nRST is Low( while I used pull up resistor on it) and also I've never program it, So this GPIO shouldn't be configured as an active-low Reset!

Is it normal for the P0.21/nRST to be Low in this situation?

[bardia3000]

Sorry Sigurd, Is it possible to answer me?

[Sigurd]

Hi,

bardia3000 said:

Is it normal for the P0.21/nRST to be Low in this situation?

No, in this situation the pin should not be low.

Do you see this issue on several custom boards, or is it only one board ?

[bardia3000]

There was a problem about this pin, I solved It, It was connected to another chip, but It can be unsoldered, now the NRST is high, but still the same problem happens, It cannot find the nrf52811.

[Sigurd]

bardia3000 said:

but still the same problem happens, It cannot find the nrf52811.

1) Do you see this issue on several custom boards, or is it only one board ?

2) Could you try to power it at 3V, and see if you are able to program it then ?

3) Also make sure that you have not accidentally switched SWDCLK and SWDIO when connecting the debugger.