1.. zephyr:board:: saml21_xpro
2
3Overview
4********
5
6The SAM L21 Xplained Pro evaluation kit is ideal for evaluation and
7prototyping with the SAM L21 Cortex®-M0+ processor-based
8microcontrollers. The kit includes Atmel’s Embedded Debugger (EDBG),
9which provides a full debug interface without the need for additional
10hardware.
11
12Hardware
13********
14
15- SAML21J18 ARM Cortex-M0+ processor at 48 MHz
16- 32.768 kHz crystal oscillator
17- 256 KiB flash memory, 32 KiB of SRAM, 8KB Low Power SRAM
18- One yellow user LED
19- One mechanical user push button
20- One reset button
21- On-board USB based EDBG unit with serial console
22
23Supported Features
24==================
25
26.. zephyr:board-supported-hw::
27
28Pin Mapping
29===========
30
31The SAM L21 Xplained Pro evaluation kit has 2 GPIO controllers. These
32controllers are responsible for pin muxing, input/output, pull-up, etc.
33
34For more details please refer to `SAM L21 Family Datasheet`_ and the `SAM L21
35Xplained Pro Schematic`_.
36
37.. image:: img/atsaml21-xpro-pinout.jpg
38     :align: center
39     :alt: SAML21-XPRO-pinout
40
41Default Zephyr Peripheral Mapping:
42----------------------------------
43- SERCOM0 SPI MISO : PA04
44- SERCOM0 SPI MOSI : PA06
45- SERCOM0 SPI SCK  : PA07
46- SERCOM1 USART TX : PA18
47- SERCOM1 USART RX : PA19
48- SERCOM2 I2C SDA  : PA08
49- SERCOM2 I2C SCL  : PA09
50- SERCOM3 USART TX : PA22
51- SERCOM3 USART RX : PA23
52- SERCOM4 USART TX : PB08
53- SERCOM4 USART RX : PB09
54- SERCOM5 SPI MISO : PB16
55- SERCOM5 SPI MOSI : PB22
56- SERCOM5 SPI SCK  : PB23
57- USB DP           : PA25
58- USB DM           : PA24
59- GPIO SPI CS      : PB17
60- GPIO/PWM LED0    : PB10
61
62System Clock
63============
64
65The SAML21 MCU is configured to use the 32.768 kHz external oscillator
66with the on-chip PLL generating the 48 MHz system clock.
67
68Serial Port
69===========
70
71The SAML21 MCU has six SERCOM based USARTs with two configured as USARTs in
72this BSP. SERCOM3 is the default Zephyr console.
73
74- SERCOM1 115200 8n1 - connected to EXT2 and EXT3
75- SERCOM3 115200 8n1 - connected to the onboard Atmel Embedded Debugger (EDBG)
76- SERCOM4 115200 8n1 - connected to EXT1
77
78PWM
79===
80
81The SAML21 MCU has 3 TCC based PWM units with up to 4 outputs each and a period
82of 24 bits or 16 bits.  If :code:`CONFIG_PWM_SAM0_TCC` is enabled then LED0 is
83driven by TCC0 instead of by GPIO.
84
85SPI Port
86========
87
88The SAML21 MCU has 6 SERCOM based SPIs, with two configured as SPI in this BSP.
89
90- SERCOM0 - connected to EXT1
91- SERCOM5 - connected to EXT2 and EXT3
92
93Programming and Debugging
94*************************
95
96The SAM L21 Xplained Pro comes with a Atmel Embedded Debugger (EDBG).  This
97provides a debug interface to the SAML21 chip and is supported by
98OpenOCD.
99
100Flashing
101========
102
103#. Build the Zephyr kernel and the ``hello_world`` sample application:
104
105   .. zephyr-app-commands::
106      :zephyr-app: samples/hello_world
107      :board: saml21_xpro
108      :goals: build
109      :compact:
110
111#. Connect the SAM L21 Xplained Pro to your host computer using the USB debug
112   port.
113
114#. Run your favorite terminal program to listen for output. Under Linux the
115   terminal should be :code:`/dev/ttyACM0`. For example:
116
117   .. code-block:: console
118
119      $ picocom -b 115200 /dev/ttyACM0
120
121   - Speed: 115200
122   - Data: 8 bits
123   - Parity: None
124   - Stop bits: 1
125
126#. To flash an image:
127
128   .. zephyr-app-commands::
129      :zephyr-app: samples/hello_world
130      :board: saml21_xpro
131      :goals: flash
132      :compact:
133
134   You should see "Hello World! saml21_xpro" in your terminal.
135
136References
137**********
138
139.. target-notes::
140
141.. _Microchip website:
142    https://www.microchip.com/en-us/development-tool/atsaml21-xpro-b
143
144.. _SAM L21 Family Datasheet:
145    https://ww1.microchip.com/downloads/en/DeviceDoc/SAM_L21_Family_DataSheet_DS60001477C.pdf
146
147.. _SAM L21 Xplained Pro Schematic:
148    https://ww1.microchip.com/downloads/en/DeviceDoc/SAML21-Xplained-Pro_Design-Documentation.zip
149