blob: 2051b9efa189096b981924f5201807b5ce35e516 [file] [log] [blame]
.. _atsaml21_xpro:
SAM L21 Xplained Pro Evaluation Kit
###################################
Overview
********
The SAM L21 Xplained Pro evaluation kit is ideal for evaluation and
prototyping with the SAM L21 Cortex®-M0+ processor-based
microcontrollers. The kit includes Atmels Embedded Debugger (EDBG),
which provides a full debug interface without the need for additional
hardware.
.. image:: img/atsaml21-xpro.jpg
:align: center
:alt: ATSAML21-XPRO
Hardware
********
- ATSAML21J18 ARM Cortex-M0+ processor at 48 MHz
- 32.768 kHz crystal oscillator
- 256 KiB flash memory, 32 KiB of SRAM, 8KB Low Power SRAM
- One yellow user LED
- One mechanical user push button
- One reset button
- On-board USB based EDBG unit with serial console
Supported Features
==================
The atsaml21_xpro board configuration supports the following hardware
features:
.. list-table::
:header-rows: 1
* - Interface
- Controller
- Driver / Component
* - NVIC
- on-chip
- nested vector interrupt controller
* - Flash
- on-chip
- Can be used with LittleFS to store files
* - SYSTICK
- on-chip
- systick
* - WDT
- on-chip
- Watchdog
* - GPIO
- on-chip
- I/O ports
* - PWM
- on-chip
- Pulse Width Modulation
* - USART
- on-chip
- Serial ports
* - I2C
- on-chip
- I2C ports
* - SPI
- on-chip
- Serial Peripheral Interface ports
* - TRNG
- on-chip
- True Random Number Generator
Other hardware features are not currently supported by Zephyr.
The default configuration can be found in the Kconfig
``boards/arm/atsaml21_xpro/atsaml21_xpro_defconfig``.
Pin Mapping
===========
The SAM L21 Xplained Pro evaluation kit has 2 GPIO controllers. These
controllers are responsible for pin muxing, input/output, pull-up, etc.
For mode details please refer to `SAM L21 Family Datasheet`_ and the `SAM L21
Xplained Pro Schematic`_.
.. image:: img/atsaml21-xpro-pinout.jpg
:align: center
:alt: ATSAML21-XPRO-pinout
Default Zephyr Peripheral Mapping:
----------------------------------
- SERCOM0 SPI MISO : PA04
- SERCOM0 SPI MOSI : PA06
- SERCOM0 SPI SCK : PA07
- SERCOM1 USART TX : PA18
- SERCOM1 USART RX : PA19
- SERCOM2 I2C SDA : PA08
- SERCOM2 I2C SCL : PA09
- SERCOM3 USART TX : PA22
- SERCOM3 USART RX : PA23
- SERCOM4 USART TX : PB08
- SERCOM4 USART RX : PB09
- SERCOM5 SPI MISO : PB16
- SERCOM5 SPI MOSI : PB22
- SERCOM5 SPI SCK : PB23
- USB DP : PA25
- USB DM : PA24
- GPIO SPI CS : PB17
- GPIO/PWM LED0 : PB10
System Clock
============
The SAML21 MCU is configured to use the 32.768 kHz external oscillator
with the on-chip PLL generating the 48 MHz system clock.
Serial Port
===========
The SAML21 MCU has six SERCOM based USARTs with two configured as USARTs in
this BSP. SERCOM3 is the default Zephyr console.
- SERCOM1 115200 8n1 - connected to EXT2 and EXT3
- SERCOM3 115200 8n1 - connected to the onboard Atmel Embedded Debugger (EDBG)
- SERCOM4 115200 8n1 - connected to EXT1
PWM
===
The SAML21 MCU has 3 TCC based PWM units with up to 4 outputs each and a period
of 24 bits or 16 bits. If :code:`CONFIG_PWM_SAM0_TCC` is enabled then LED0 is
driven by TCC0 instead of by GPIO.
SPI Port
========
The SAML21 MCU has 6 SERCOM based SPIs, with two configured as SPI in this BSP.
- SERCOM0 - connected to EXT1
- SERCOM5 - connected to EXT2 and EXT3
Programming and Debugging
*************************
The SAM L21 Xplained Pro comes with a Atmel Embedded Debugger (EDBG). This
provides a debug interface to the SAML21 chip and is supported by
OpenOCD.
Flashing
========
#. Build the Zephyr kernel and the ``hello_world`` sample application:
.. zephyr-app-commands::
:zephyr-app: samples/hello_world
:board: atsaml21_xpro
:goals: build
:compact:
#. Connect the SAM L21 Xplained Pro to your host computer using the USB debug
port.
#. Run your favorite terminal program to listen for output. Under Linux the
terminal should be :code:`/dev/ttyACM0`. For example:
.. code-block:: console
$ picocom -b 115200 /dev/ttyACM0
- Speed: 115200
- Data: 8 bits
- Parity: None
- Stop bits: 1
#. To flash an image:
.. zephyr-app-commands::
:zephyr-app: samples/hello_world
:board: atsaml21_xpro
:goals: flash
:compact:
You should see "Hello World! atsaml21_xpro" in your terminal.
References
**********
.. target-notes::
.. _Microchip website:
https://www.microchip.com/en-us/development-tool/atsaml21-xpro-b
.. _SAM L21 Family Datasheet:
https://ww1.microchip.com/downloads/en/DeviceDoc/SAM_L21_Family_DataSheet_DS60001477C.pdf
.. _SAM L21 Xplained Pro Schematic:
https://ww1.microchip.com/downloads/en/DeviceDoc/SAML21-Xplained-Pro_Design-Documentation.zip