User manual

Atmel SAM D20 Xplained Pro [USER GUIDE]

42102C-MCU-02/2014

Pin on SAM D20 Function

PB16 SERCOM5 PAD[0] SPI MISO (Master In, Slave Out)

PB22 SERCOM5 PAD[2] SPI MOSI (Master Out, Slave in)

PB23 SERCOM5 PAD[3] SPI SCK (Clock Out)

Table 4-10. DGI Interface Connections when using I²C

Pin on SAM D20 Function

PA08 SERCOM2 PAD[0] SDA (Data line)

PA09 SERCOM2 PAD[1] SCL (Clock line)

Four GPIO lines are connected to the Embedded Debugger. The EDBG can monitor these lines and time

stamp pin value changes. This makes it possible to accurately time stamp events in the SAM D20 application

code. For further information on how to configure and use the GPIO monitoring features see “Embedded

Debugger” on page 6.

Table 4-11. GPIO Lines Connected to the EDBG

Pin on SAM D20 Function

PA27 GPIO0

PA28 GPIO1

PA20 GPIO2

PA21 GPIO3

4.3.4 External Programming and Debugging

The SAM D20 Xplained Pro features a Cortex

Debug Connector (10-pin) for programming and debugging an

external target. The connector is limited to the SWD interface and is intended for in-system programming and

debugging of SAM D20 devices in the users final products.

The debug connector is connected to the onboard EDBG through level shifters and switches. When an external

target voltage is detected, the EDBG will switch the SWD interface from the onboard target device to the

external debug connector and the green LED next to the connector will be lit. The voltage of the external target

must be between 1.6V and 5.0V.

Note

This connector can't be used for attaching an external debug unit for programming and debugging

the onboard device.

Table 4-12. Cortex Debug Connector

Pin on connecor Specification Function implemented

1 VCC VCC

2 SWDIO / TMS SWDIO

3 GND GND

4 SWDCLK / TCK SWDCLK

5 GND GND

6 SWO / TDO NC

7 KEY NC

8 NC / TDI NC

9 GNDDetect GND

10 nRESET nRESET