Running Chiseltests
===================

This is a brief guide on how to run Chiseltests found on some Chisel projects.

Structure
---------

- Chiseltests are located in a fixed location: ``src/test/scala``.
- The file name ends with ``Spec.scala`` and test class name with ``Spec``

Running the test
----------------

Chiseltests are run with ``sbt``. For example, to run ``DataCacheSpec`` under ``acorechip``, you should navigate to ``Entities/acorechip/chisel`` and run:

.. code-block:: bash

    sbt 'testOnly acorechip.DataCacheSpec'

Debugging
---------

In a Chiseltest, you can print with ``println``. However, this is not very helpful for debugging.

Best way to debug is to check waveforms. They don't get generated by default. You need to add ``.withAnnotations(Seq(WriteVcdAnnotation))`` after the ``test`` wrapper. For example:

.. code-block:: scala

    test(new DataCache(memory_map, config)).withAnnotations(Seq(WriteVcdAnnotation)) { c =>
    ...

After running the test, it will generate a ``<className>.vcd`` file under ``test_run_dir/test_name/``. You can open it with GTKWave:

.. code-block:: bash

    gtkwave test_run_dir/test_name/className.vcd

You can add traces to the waveform window from the panel on the left.