The nRF9161 DK supports programming and debugging external boards with Nordic System on Chip (SoC)s and System in Package (SiP)s.
To debug an external board with SEGGER J-Link OB IF, connect the Debug out connector P19 to your target board with a 10-pin flat cable.
When the external board is powered up, the interface MCU detects the supply voltage of the board and programs or debugs the target chip on the external board instead of the onboard nRF9161.
P20 can also be used as a debug out connector to program shield-mounted targets. For P19 and P20, the interface MCU detects the supply voltage on the mounted shield and programs or debugs the target.
If the interface MCU detects target power on P19 and P20, it programs or debugs the target connected to P19 by default.
If you do not have a separate power supply on the external board, the nRF9161 DK can supply power through the Debug out connector P18. To enable this, short solder bridge SB24.