User Manual

3. I/O Pin Assignment
The module pin assignment is shown in below table. The Column "MCU pin" is referring to the
ATSAMR21G18 datasheet [SAMR21]. The column “Port Configuration” is intended to help determine the
required SAMR21 port configuration..
Table 3-1 RF Front End Control
Module Pin Function MCU Pin Port Configuration
1 GND
2 GND
3 VCC
4 VCC
5 RSTN 40
6 SPI_CS 26 SERCOM1; MUX=C; DOPO=0x1; Master PAD1
7 SPI_MOSI 27 SERCOM1; MUX=C; DOPO=0x1 Master PAD2
For slave operation this pin is MISO
8 SPI_MISO 25 SERCOM1; MUX=C; DIPO=0x0 Master PAD0
For slave operation this pin is MOSI
9 SPI_SCLK 28 SERCOM1; MUX=C; DOPO=0x1 Master PAD3
10 GPIO 41 PA28 (Yellow LED; low active)
11 - Not connected
12 GND
13 RXD1 12 SERCOM0; MUX=D; PAD[3] RXPO=0x3
Can be used for UART with RTS/CTS
14 TXD1 15 SERCOM0; MUX=C; PAD[0] TXPO=0x0
Can be used for UART with RTS/CTS
15 - Not connected
16 - Not connected
17 FEM_RX_TX 22 PA13; MUX=F; FECTRL3 (LED red)
18 ANT_DIV_P 21 PA12; MUX=F; FECTRL2 (LED green)
19 GPIO/USB_DM 33 PA24 for USB MUX=G
20 GPIO/USB_DP 34 PA25 for USB MUX=G
21 - Not connected
22 RXD0 24 SERCOM2; MUX=C; PAD[3]; RXPO=0x3
23 TXD0 23 SERCOM2; MUX=C; PAD[2]; TXPO=0x1
Atmel ATSAMR21G18-MR210UA [DATASHEET]
Atmel-42475B-ATSAMR21G18-MR210UA_Datasheet_Preliminary-09/2015
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