1.

External power.

2.

Embedded Debugger USB.

3.

Target USB.

Info:  External power is required when 500mA from a USB connector is not enough to power

the board with possible extension boards. A connected USB device in a USB host application

might easily exceed this limit.

3.4.

Xplained Pro Headers and Connectors

3.4.1.

Xplained Pro Standard Extension Header

All Xplained Pro kits have one or more dual row, 20-pin, 100mil extension header. Xplained Pro MCU

boards have male headers, while Xplained Pro extensions have their female counterparts. Note that all

pins are not always connected. All connected pins follow the defined pin-out description in the table

below.

The extension headers can be used to connect a variety of Xplained Pro extensions to Xplained Pro MCU

boards or to access the pins of the target MCU on Xplained Pro MCU boards directly.

Table 3-4. Xplained Pro Standard Extension Header

Pin number

Name

Description

1

ID

Communication line to the ID chip on an extension board

2

GND

Ground

3

ADC(+)

Analog to digital converter, alternatively positive part of differential

ADC

4

ADC(-)

Analog to digital converter, alternatively negative part of differential

ADC

5

GPIO1

General purpose I/O

6

GPIO2

General purpose I/O

7

PWM(+)

Pulse width modulation, alternatively positive part of differential

PWM

8

PWM(-)

Pulse width modulation, alternatively negative part of differential

PWM

9

IRQ/GPIO

Interrupt request line and/or general purpose I/O

10

SPI_SS_B/

GPIO

Slave select for SPI and/or general purpose I/O

11

12

13

UART_RX

Receiver line of target device UART

14

UART_TX

Transmitter line of target device UART

Atmel SAM R21 Xplained Pro [USER GUIDE]

Atmel-42243D-SAM-R21-Xplained-Pro_User Guide-04/2016

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