NOTE the following is a work-in-progress (WIP) and has not reached a minor release point. If you happen to come across this public repository feel free to try it out and contribute. This repository will be unstable until the first minor release 0.1. This repository is a merge of the mn and gizflo projects.

The rhea python package is a collection of HDL cores written in MyHDL. The rhea package also includes a small set of utilities to augment the myhdl types and functions as well as FPGA build automation tools.

Pronounced ray (as in ray-gun), just a random name and not pronounced the same as the bird or moon.

• myhdl currently 0.9 (watch the 1.0 rhea branch)
• pytest for the test suite
• Pillow >= 2.9, some video tests utilize the imaging library
• FPGA vendor tools, only for automated build tools.

If you are not familiar with myhdl starting with the myhdl manual and examples is recommended. General myhdl questions can be answered on the #myhdl IRC channel or on the myhdl mailing-list.
I am often available to answer rhea specific questions on the previously mentioned communications or the rhea gitter can be used.

IMPORTANT NOTE this repository is under development and is using features from a development version of MyHDL (1.0dev). If you wish to try out this package get the development myhdl (you will need to clone it and install the source). The first rhea release will not occur until myhdl 1.0 is released (probably much later).

Getting close to the fist minor release. The first minor release will contain a small collection of documented cores and frameworks.

This code/package is licensed under the MIT license. This allows anyone to use the package in their projects with no limitations.
Questions and other license options email me.

The following are the definition of some terms used in this README :

• cores : the building blocks of a system. Also, know as IP (intellectual property).

• system : the digital design being implement, synonymous with system-on-a-chip, not using the term system-on-a-chip (SoC) because SoC it is typically reserved for systems that contains a CPU. In this document and the example the system can be a SoC or other complex digital design.

• register : collection of bits that retain state.

• register file : collection of same-sized registers, a register file is organized into read-write entities and read-only entities. A register-file is a programming/configuration interface to a core.

• CSR: control and status registers also known as config and status.
  This term is commonly used for the memory-mapped interface to the cores.

To get started with the latest version (repo version) checkout out the code and run setup in develop mode. The dependencies listed above need to be installed.

Install the latest myhdl.

  >> git clone https://github.com/jandecaluwe/myhdl
  >> sudo python setup.py install
  >> cd ..

or

  >> pip install git+https://github.com/jandecaluwe/myhdl

After the dependencies have been installed clone this repository to get started.

  >> git clone https://github.com/cfelton/rhea
  >> cd rhea
  # requires setuptools
  >> sudo python setup.py develop

The tests can be run from the test directory.

  # attempt to run the tests
  >> cd test
  >> py.test

If FPGA vendor tools (Xilinx, Altera, Lattice, Yosys) are installed the build examples can be run to generate bitstreams.

  # try to compile one of the examples 
  # (requires FPGA tools installed)
  >> cd ../examples/build/
  >> python ex_xula.py

The test directory contains test for the different cores in the package.

Run the tests in the test directory:

>> cd test
>> py.test

Run the tests in the examples directory:

>> cd examples
>> py.test

In the example directory are projects that demonstrate how to build systems using the cores and various tools and target a particular FPGA development board. The examples/build contains LED blinky examples for many different boards.