| .. _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 Atmel’s Embedded Debugger (EDBG), |
| which provides a full debug interface without the need for additional |
| hardware. |
| |
| .. image:: img/atsaml21-xpro.png |
| :width: 500px |
| :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.png |
| :width: 500px |
| :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 |
