User Manual

Module Pin MCU Function MCU Pin Port and SERCOM Configuration
26 UART RTS 11 SERCOM0; MUX=D; PAD[2] TXPO=0x2
13 UART CTS 12 SERCOM0; MUX=D; PAD[3] TXPO=0x2
The signals in this table are not available as module IO. More information about the FLASH IC can be
found in its related datasheet. (ADESTO)
1.2.3. 32kHz Crystal
PA00 and PA01 are used for the 32kHz crystal. This pins are not available as module IO.
1.2.4. SAM R21 USB Availability
The USB pins are made available as differential pair routed GPIO’s. A base board with the required
connection hardware can support an USB interface.
Table 1-3 SAM R21 USB Availability
Module Pin Function MCU Pin Port Configuration or Xplain Function
19 GPIO or USB_D+ 33 PA24: For USB MUX=G
20 SPIO or USB_D- 34 PA25: For USB MUX=G
The module power supply can’t be operated directly from a 5V USB source. The module base board has
to implement the required voltage regulator.
1.3. RF Front End Control
The antenna diversity signals ANT_DIV_P/N are used to control the diversity switch U4. The signal
ANT_DIV_P is available at the IO ring pin 18 to indicate the antenna currently in use.
In addition at pin 17, the RX_TX indicator signal is available to indicate if the module is currently in
transmit mode.
Atmel ATSAMR21G18-MR210UA [DATASHEET]
Atmel-42475B-ATSAMR21G18-MR210UA_Datasheet_Preliminary-09/2015
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