Atmel Xplained Pro Evaluation Kit for the ATSAMD21J18A Microcontroller ATSAMD21-XPRO ATSAMD21-XPRO Data Sheet
Product codes
ATSAMD21-XPRO
Atmel SAM D21 Xplained Pro [USER GUIDE]
42220A-MCU-02/2014
11
Pin on EXT2
SAM D21 pin
Function
Shared functionality
9 [IRQ/GPIO]
PB14
EXTINT[14]
10 [SPI_SS_B/GPIO]
PB15
GPIO
11 [TWI_SDA]
PA08
SERCOM2 PAD[0] I²C SDA
EXT1, EXT3, and EDBG
12 [TWI_SCL]
PA09
SERCOM2 PAD[1] I²C SCL
EXT1, EXT3, and EDBG
13 [USART_RX]
PB11
SERCOM4 PAD[1] UART RX
1
EXT3
14 [USART_TX]
PB10
SERCOM4 PAD[0] UART TX
1
EXT3
15 [SPI_SS_A]
PA17
SERCOM1 PAD[1] SPI SS
16 [SPI_MOSI]
PA18
SERCOM1 PAD[2] SPI MOSI
17 [SPI_MISO]
PA16
SERCOM1 PAD[0] SPI MISO
18 [SPI_SCK]
PA19
SERCOM1 PAD[3] SPI SCK
19 [GND]
-
-
GND
20 [VCC]
-
-
VCC
Notes:
1
The SERCOM4 module is shared between EXT1, 2 and 3 UART's, but uses different pins on EXT1 and EXT2/3.
Table 4-3. Extension Header EXT3
Pin on EXT3
SAM D21 pin
Function
Shared functionality
1 [ID]
-
-
Communication line to ID chip
on extension board.
2 [GND]
-
-
GND
3 [ADC(+)]
PA02
AIN[0]
4 [ADC(-)]
PA03
AIN[1]
1
USB ID
5 [GPIO1]
PB30
GPIO
Onboard LED0
6 [GPIO2]
PA15
GPIO
Onboard SW0
7 [PWM(+)]
PA12
TC2/WO[0]
8 [PWM(-)]
PA13
TC2/WO[1]
2
Serial Flash SS
9 [IRQ/GPIO]
PA28
EXTINT[8]
10 [SPI_SS_B/GPIO]
PA27
GPIO
11 [TWI_SDA]
PA08
SERCOM2 PAD[0] I²C SDA
EXT1, EXT2, and EDBG
12 [TWI_SCL]
PA09
SERCOM2 PAD[1] I²C SCL
EXT1, EXT2, and EDBG
13 [USART_RX]
PB11
SERCOM4 PAD[1] UART RX
3
14 [USART_TX]
PB10
SERCOM4 PAD[0] UART TX
3
15 [SPI_SS_A]
PB17
SERCOM5 PAD[1] SPI SS
16 [SPI_MOSI]
PB22
SERCOM5 PAD[2] SPI MOSI
EDBG and Serial Flash
17 [SPI_MISO]
PB16
SERCOM5 PAD[0] SPI MISO
EDBG and Serial Flash
18 [SPI_SCK]
PB23
SERCOM5 PAD[3] SPI SCK
EDBG and Serial Flash
19 [GND]
-
-
GND
20 [VCC]
-
-
VCC
Notes:
1
PA03 can be used by USB ID or EXT3 PIN4 by changing the position of the jumper JS300 on J307.
2
PA13 is by default connected to the Serial Flash SS line and is disconnected from the EXT3 PIN8. This can be changed by
moving the 0-Ohm resistor R314 to R313.
3
The SERCOM4 module is shared between EXT1, 2 and 3 UART's, but uses different pins on EXT1 and EXT2/3.
4.2
Peripherals
4.2.1
Crystal
The SAM D21 Xplained Pro kit contains one crystals that can be used as clock source for the SAM D21 device.
The crystal has a cut-strap next to it that can be used to measure the oscillator safety factor. This is done by