36.7 Programming and Debugging Ports

For programming and/or debugging the SAM D20 device, it must be connected using the Serial Wire Debug (SWD) interface. Currently the SWD interface is supported by several Microchip and third party programmers and debuggers, like the JTAGICE3, SAM-ICE, ATMEL_ICE, or SAM D20 Xplained Pro ( SAM D20 evaluation kit) Embedded Debugger.

Refer to the JTAGICE3, SAM-ICE, ATMEL_ICE, or SAM D20 Xplained Pro user guides for additional information on debugging and programming connections and options. For connecting to any other programming or debugging tool, refer to that specific programmer or debugger’s user guide.

The SAM D20 Xplained Pro evaluation board for the SAM D20 supports programming and debugging through the onboard embedded debugger and thus no external programmer or debugger is needed.

A pull-up resistor on the SWCLK pin is critical for reliable operations. For additional information, refer to the related link.

Figure 36-9. SWCLK Circuit Connections
Table 36-8. SWCLK Circuit Connections
Header Signal NameDescriptionRecommended Pin Connection
SWDCLKSerial wire clock pinPull-up resistor 1kΩ
SWDIOSerial wire bidirectional data pin
RESETTarget device reset pin, active low
GNDGround