The nRF9160 DK supports Serial Wire Debug (SWD) programming interfaces for both onboard and off-board nRF targets.
The primary target for programming and debugging in the Development Kit (DK) is the nRF9160 System in Package (SiP). The interface MCU also supports programming the onboard nRF52840 as well as external nRF devices fitted on a shield or through a connector to external boards such as the user's own prototypes.
The interface MCU will automatically detect if external targets are plugged in. The PROG/DEBUG switch (SW10) is used to select nRF9160 or nRF52840 for programming or debugging on board. Note that there are significant limitations on using the nRF52840 on the nRF9160 DK. For more information, see nRF9160 DK board control.