py4hw

py4hw is an HDL library based on python to create digital circuits (mainly) following a structural design methodology. It is highly influenced by some principles used in JHDL but using the power of Python.

When people see Python and HDL in the same sentence they automatically associate it with two ideas:

This is an attempt to generate Verilog from Python code with an HLS approach
This will generate terribly inefficient Verilog

The answer to both questions is NO. py4hw is NOT [yet] intended to be a python HLS tool. It actually starts from a bottom-up approach modelling basic logic gates. In fact, you can generate Verilog code at a very fine-grain.

Features

Cycle-based Simulation
Clear separation of design styles
- Structural
- Behavioural
  - Combinational
  - Sequential (RTL)
  - Algorithmic
Schematic Rendering
Interactive Simulation
Verilog Generation (for Structural, Combinational and Sequential design styles)
WaveDrom generation
Library of predefined circuits
Pypi based distribution
Jupyter Notebook integration
Integration with edalize
Support for existing Hardware platforms (Terasic DE0, and DE1SoC so far)

Follow the jump start tutorial in a jypyter notebook! or access the static html version here

Contributing

Contributors are more than welcome :-)

I've identifyied a number of low-effort aspects that should be done

change the use of nbwavedrom by wavedrom
correct synchronization of wire names and waveforms in WaveformWindow and support for scrolling, zooming and paning.
avoid complete redrawing in interactive workbench

..and other high effort tasks

improve the place & route algorithm in the schematic viewer
collapse interfaces in the schematic viewer
support additional hardware platforms
transpile algorithmic into RTL

Publications

Cite as

@conference{castells2023streamlining,
  author       = {David Castells-Rufas and Gemma Rotger and David Novo},
  title        = {Streamlining FPGA Circuit Design and Verification with Python and py4hw},
  booktitle    = {XI Southern Programmable Logic Conference},
  year         = 2023,
  month        = mar,
  address      = {San Luis, Argentina},
  doi          = {10.5281/zenodo.8325670}
}

Metadata

Release files for py4hw 2026.4

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for py4hw 2026.4
File	Size	Uploaded
py4hw-2026.4.tar.gz	160.3 kB	Sep 16, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for py4hw 2026.4
File	Interpreter	ABI	Platform	Reset
py4hw-2026.4-py3-none-any.whl 172.2 kB Sep 16, 2026	Python 3	none	any	Details

Total release size: 332.6 kB

Release files / py4hw-2026.4.tar.gz

Download URL	py4hw-2026.4.tar.gz
Size	160.3 kB
Tags	Source
SHA-256 checksum How to use checksums	`d044a9dd0c2c49fb928715534a8f5ba99b247a5dde4f5bafdd3ee8dac461c0df`
BLAKE2b-256 checksum How to use checksums	`643fda1dd6e459948ec9100ed188944b5ed4768d426e99531c1f53c1380dd5ff`
Upload date	Sep 16, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/6.2.0 CPython/3.14.3`

Release files / py4hw-2026.4-py3-none-any.whl

Download URL	py4hw-2026.4-py3-none-any.whl
Size	172.2 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`9a8370923a039c5683d0eb89f5a9c3ede499542e8c2931249e498f5d92fa4928`
BLAKE2b-256 checksum How to use checksums	`e7987ecb2f193f4a54eb48998b4abcc2d213300ca53c8c8c246cb65f1f854595`
Upload date	Sep 16, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/6.2.0 CPython/3.14.3`