4.4.2.

Virtual COM port

The Embedded Debugger acts as a Virtual Com Port gateway by using one of the ATSAMR21G18A

UARTs.

Table 4-12. Virtual COM Port Connections

Pin on SAM R21

Function

PA04

SERCOM0 PAD[0] UART TXD (SAM R21 TX line)

PA05

SERCOM1 PAD[1] UART RXD (SAM R21 RX line)

Related Links

Embedded Debugger on page 8

4.4.3.

Atmel Data Gateway Interface

The Embedded Debugger features an Atmel Data Gateway Interface (DGI) by using either an SPI or I²C

port. The DGI can be used to send a variety of data from the SAM R21 to the host PC.

Table 4-13. DGI Interface Connections When Using SPI

Pin on SAM R21

Function

PA27

GPIO SPI SS (Slave select) (SAM R21 is Master)

PB02

SERCOM5 PAD[0] SPI MISO (Master In, Slave Out)

PB22

SERCOM5 PAD[2] SPI MOSI (Master Out, Slave in)

PB23

SERCOM5 PAD[3] SPI SCK (Clock Out)

Table 4-14. DGI Interface Connections When Using I²C

Pin on SAM R21

Function

PA16

SERCOM1 PAD[0] I²C SDA (Data line)

PA17

SERCOM1 PAD[1] I²C SCL (Clock line)

Four GPIO lines are connected to the Embedded Debugger. The EDBG can monitor these lines and time

stamp pin value changes. This makes it possible to accurately time stamp events in the SAM R21

application code.

Table 4-15. GPIO Lines Connected to the EDBG

Pin on SAM R21

Function

PA08

GPIO0

PA09

GPIO1

PA12

GPIO2

PA14

GPIO3

Related Links

Embedded Debugger on page 8

Atmel SAM R21 Xplained Pro [USER GUIDE]

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

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