.. _iotdk:

DesignWare(R) ARC(R) IoT Development Kit
########################################

Overview
********

The DesignWare(R) ARC(R) IoT Development Kit is a versatile platform that
includes the necessary hardware and software to accelerate software
development and debugging of sensor fusion, voice recognition, and face
detection designs. The ARC IoT Development Kit includes a silicon
implementation of the ARC Data Fusion IP Subsystem running at 144 MHz on
SMIC's 55-nm ultra-low power process, and a rich set of peripherals commonly
used in IoT designs such as USB, UART, SPI, I2C, PWM, SDIO, and ADCs.

.. image:: iotdk.jpg
   :align: center
   :alt: DesignWare(R) ARC(R)IoT Development Kit (synopsys.com)

For details about the board, see: `ARC IoT Development Kit
(IoTDK) <https://www.synopsys.com/dw/ipdir.php?ds=arc_iot_development_kit>`__


Hardware
********

For hardware feature details, refer to : `ARC IoT Development Kit
<https://embarc.org/project/arc-iot-development-kit/>`__


Programming and Debugging
*************************

Required Hardware and Software
==============================

To use Zephyr RTOS applications on the IoT Development Kit board, a few
additional pieces of hardware are required.

* A micro USB cable provides power to the board; however, if the
  board is to run standalone, the universal switching power adaptor (110-240V
  AC to 5V DC), provided in the package, can be used to power the board.

* :ref:`The Zephyr SDK <toolchain_zephyr_sdk>`

* Terminal emulator software for use with the USB-UART. Suggestion:
  `Putty Website`_.

* (optional) A collection of Pmods, Arduino modules, or Mikro modules.
  See `Digilent Pmod Modules`_ or develop your custom interfaces to attach
  to the Pmod connector.

Set up the ARC IoT Development Kit
==================================

To run Zephyr application on IoT Development Kit, you need to
setup the board correctly.

* Connect the digilent usb cable from your host to the board.

* Connect the 5V DC power supply to your board (optional).

Set up Zephyr Software
======================

Building Sample Applications
==============================

You can try many of the sample applications or tests, but let us discuss
the one called :ref:`hello_world`.
It is found in :zephyr_file:`samples/hello_world`.

Configuring
-----------

You may need to write a prj_arc.conf file if the sample doesn't have one.
Next, you can use the menuconfig rule to configure the target. By specifying
``iotdk`` as the board configuration, you can select the ARC IoT Development
Kit board support for Zephyr.

.. zephyr-app-commands::
   :board: iotdk
   :zephyr-app: samples/hello_world
   :goals: menuconfig


Building
--------

You can build an application in the usual way.  Refer to
:ref:`build_an_application` for more details. Here is an example for
:ref:`hello_world`.

.. zephyr-app-commands::
   :board: iotdk
   :zephyr-app: samples/hello_world
   :maybe-skip-config:
   :goals: build

Connecting Serial Output
=========================

In the default configuration, Zephyr's IoT Development Kit images support
serial output via the USB-UART on the board.  To enable serial output:

* Open a serial port emulator (i.e. on Linux minicom, putty, screen, etc)

* Specify the tty driver name, for example, on Linux this may be
  :file:`/dev/ttyUSB0`

* Set the communication settings to:


========= =====
Parameter Value
========= =====
Baud:     115200
Data:     8 bits
Parity:    None
Stopbits:  1
========= =====

Debugging
==========

Using the latest version of Zephyr SDK(>=0.9), you can debug and flash IoT
Development Kit directly.

One option is to build and debug the application using the usual
Zephyr build system commands.

.. zephyr-app-commands::
   :board: iotdk
   :app: <my app>
   :goals: debug

At this point you can do your normal debug session. Set breakpoints and then
'c' to continue into the program.

The other option is to launch a debug server, as follows.

.. zephyr-app-commands::
   :board: iotdk
   :app: <my app>
   :goals: debugserver

Then connect to the debug server at the IoT Development Kit from a second
console, from the build directory containing the output :file:`zephyr.elf`.

.. code-block:: console

   $ cd <my app>
   $ $ZEPHYR_SDK_INSTALL_DIR/arc-zephyr-elf/bin/arc-zephyr-elf-gdb zephyr.elf
   (gdb) target remote localhost:3333
   (gdb) load
   (gdb) b main
   (gdb) c

Flashing
========

If you just want to download the application to the IoT Development Kit's CCM
and run, you can do so in the usual way.

.. zephyr-app-commands::
   :board: iotdk
   :app: <my app>
   :goals: flash

This command still uses openocd and gdb to load the application elf file to
IoT Development Kit, but it will load the application and immediately run. If
power is removed, the application will be lost since it wasn't written to flash.

Most of the time you will not be flashing your program but will instead debug
it using openocd and gdb. The program can be download via the USB cable into
the code and data memories.

When you are ready to deploy the program so that it boots up automatically on
reset or power-up, you can follow the steps to place the program on SPI-FLASH
or internal eFlash.

For instructions on how to write your program to FLASH, refer to the
documentation on the IoT Development Kit at the `embARC website`_.

Release Notes
*************

References
**********

.. _embARC website: https://www.embarc.org

.. _Designware ARC IoT Development Kit website: <https://www.synopsys.com/dw/ipdir.php?ds=arc_iot_development_kit>`_

.. _Digilent Pmod Modules: http://store.digilentinc.com/pmod-modules

.. _Putty website: http://www.putty.org
