User Manual

Atmel SAM R21 Xplained Pro [USER GUIDE]
42243B-MCU-06/2014
15
4.4.1 Serial Wire Debug
The Serial Wire Debug (SWD) use two pins to communicate with the target. For further information on how to
use the programming and debugging capabilities of the EDBG, see “Embedded Debugger” on page 6.
Table 4-11. SWD Connections
Pin on SAM R21 Function
PA30 SWD clock
PA31 SWD data
4.4.2 Virtual COM port
The Embedded Debugger acts as a Virtual Com Port gateway by using one of the ATSAMR21G18A UARTs.
For further information on how to use the Virtual COM port see “Embedded Debugger” on page 6.
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)
4.4.3 Atmel Data Gateway Interface
The Embedded Debugger features an Atmel Data Gateway Interface (DGI) by using either a SPI or I²C port.
The DGI can be used to send a variety of data from the SAM R21 to the host PC. For further information on
how to use the DGI interface see “Embedded Debugger” on page 6.
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. For further information on how to configure and use the GPIO monitoring features see “Embedded
Debugger” on page 6.
Table 4-15. GPIO Lines Connected to the EDBG
Pin on SAM R21 Function
PA08 GPIO0
PA09 GPIO1
PA12 GPIO2
PA14 GPIO3