SWD interface
The SWD debug interface is used for programming the firmware and accessing registers. SWD can be accessed, for example, with SEGGER J-Link debugger hardware. A standard 2 x 5 pin header interface can be found on the nRF9160 DK.
UART interface UART communicates through the GPIO pins. All GPIO pins can be configured for UART communication in the application firmware. The UART interface can be used to control the DUT using AT commands.