Atmel SAM R21 Xplained Pro [USER GUIDE]
42243A-MCU-02/2014
6
3.
Xplained Pro
Xplained Pro is an evaluation platform that provides the full Atmel microcontroller experience. The platform
consists of a series of Microcontroller (MCU) boards and extension boards that are integrated with Atmel
Studio, have Atmel Software Framework (ASF) drivers and demo code, support data streaming and more.
Xplained Pro MCU boards support a wide range of Xplained Pro extension boards that are connected through
a set of standardized headers and connectors. Each extension board has an identification (ID) chip to uniquely
identify which boards are mounted on a Xplained Pro MCU board. This information is used to present relevant
user guides, application notes, datasheets and example code through Atmel Studio. Available Xplained Pro
MCU and extension boards can be purchased in the
1
.
3.1
Embedded Debugger
The SAM R21 Xplained Pro contains the Atmel Embedded Debugger (EDBG) for on-board debugging. The
EDBG is a composite USB device of three interfaces; a debugger, Virtual COM Port and Data Gateway
Interface (DGI).
In conjunction with Atmel Studio, the EDBG debugger interface can program and debug the ATSAMR21G18A.
On the SAM R21 Xplained Pro, the SWD interface is connected between the EDBG and the ATSAMR21G18A.
The Virtual COM Port is connected to a UART port on the ATSAMR21G18A (see section
for pinout), and provides an easy way to communicate with the target
application through simple terminal software. It offers variable baud rate, parity and stop bit settings. Note that
the settings on the target device UART must match the settings given in the terminal software.
The DGI consists of several physical data interfaces for communication with the host computer. See section
“Embedded Debugger Implementation” on page 14
for available interfaces and pinout. Communication
over the interfaces are bidirectional. It can be used to send events and values from the ATSAMR21G18A, or
as a generic printf-style data channel. Traffic over the interfaces can be timestamped on the EDBG for more
accurate tracing of events. Note that timestamping imposes an overhead that reduces maximal throughput. The
DGI uses a proprietary protocol, and is thus only compatible with Atmel Studio.
The EDBG controls two LEDs on SAM R21 Xplained Pro, a power LED and a status LED.
shows how the LEDs are controlled in different operation modes.
Table 3-1. EDBG LED Control
Operation mode
Power LED
Status LED
Normal operation
Power LED is lit when power is
applied to the board.
Activity indicator, LED flashes
every time something happens on
the EDBG.
Bootloader mode (idle)
The power LED and the status LED blinks simultaneously.
Bootloader mode (firmware
upgrade)
The power LED and the status LED blinks in an alternating pattern.
For further documentation on the EDBG, see the
2
.
3.2
Hardware Identification System
All Xplained Pro compatible extension boards have an Atmel ATSHA204 CryptoAuthentication™ chip mounted.
This chip contains information that identifies the extension with its name and some extra data. When an
Xplained Pro extension board is connected to an Xplained Pro MCU board the information is read and sent
to Atmel Studio. The Atmel Kits extension, installed with Atmel Studio, will give relevant information, code
examples and links to relevant documents.
Table 3-2, “Xplained Pro ID Chip Content” on page 6
data fields stored in the ID chip with example content.
Table 3-2. Xplained Pro ID Chip Content
Data Field
Data Type
Example Content
Manufacturer
ASCII string
Atmel’\0’
Product Name
ASCII string
Segment LCD1 Xplained Pro’\0’
Product Revision
ASCII string
02’\0’
Product Serial Number
ASCII string
1774020200000010’\0’
1
http://store.atmel.com/ATSAMR21-XPRO
2
http://www.atmel.com/Images/Atmel-42096-Microcontrollers-Embedded-Debugger_User-Guide.pdf
