SAM D20 Xplained Pro contains an Embedded Debugger (EDBG) that can be used to program and debug the ATSAMD20J18A using Serial Wire Debug (SWD). The Embedded Debugger also include a Virtual Com port interface over UART, an Atmel Data Gateway Interface over SPI and TWI and it monitors four of the SAM D20 GPIOs. Atmel Studio can be used as a front end for the Embedded Debugger.