User manual

Atmel SAM D20 Xplained Pro [USER GUIDE]
42102C-MCU-02/2014
10
Pin on EXT2 SAM D20 pin Function Shared functionality
9 PB14 EXTINT[14]
10 PB15 GPIO
11 PA08 SERCOM2 PAD[0] I²C SDA EXT1, EXT3 and EDBG
12 PA09 SERCOM2 PAD[1] I²C SCL EXT1, EXT3 and EDBG
13 PB13 SERCOM4 PAD[1] UART RX
1
14 PB12 SERCOM4 PAD[0] UART TX
1
15 PA17 SERCOM1 PAD[1] SPI SS
16 PA18 SERCOM1 PAD[2] SPI MOSI
17 PA16 SERCOM1 PAD[0] SPI MISO
18 PA19 SERCOM1 PAD[3] SPI SCK
19 - - GND
20 - - VCC
Notes:
1
The SERCOM4 module is shared between EXT1, 2 and 3 UART's, but uses different pins.
Table 4-3. Extension Header EXT3
Pin on EXT3 SAM D20 pin Function Shared functionality
1 - - Communication line to ID chip on
extension board.
2 - - GND
3 PA02 AIN[0]
4 PA03 AIN[1]
5 PB30 GPIO
6 PA15 GPIO Onboard SW0
7 PA12 TC2/WO[0]
8 PA13 TC2/WO[1]
9 PA28 EXTINT[8]
10 PA27 GPIO
11 PA08 SERCOM2 PAD[0] I²C SDA EXT1, EXT2 and EDBG
12 PA09 SERCOM2 PAD[1] I²C SCL EXT1, EXT2 and EDBG
13 PB11 SERCOM4 PAD[3] UART RX
1
14 PB10 SERCOM4 PAD[2] UART TX
1
15 PB17 SERCOM5 PAD[1] SPI SS
16 PB22 SERCOM5 PAD[2] SPI MOSI EDBG
17 PB16 SERCOM5 PAD[0] SPI MISO EDBG
18 PB23 SERCOM5 PAD[3] SPI SCK EDBG
19 - - GND
20 - - VCC
Notes:
1
The SERCOM4 module is shared between EXT1, 2 and 3 UART's, but uses different pins.
4.2 Peripherals
4.2.1 Crystal
The SAM D20 Xplained Pro kit contains one crystals that can be used as clock source for the SAM D20 device.
The crystal has a cut-strap next to it that can be used to measure the oscillator safety factor. This is done by
cutting the strap and adding a resistor across the strap. More information about oscillator allowance and safety
factor can be found in appnote AVR4100
1
.
1
http://www.atmel.com/images/doc8333.pdf