This directory contains the sources of GHDL, the open-source analyzer, compiler, simulator and (experimental) synthesizer for VHDL, a Hardware Description Language (HDL). GHDL is not an interpreter: it allows you to analyse and elaborate sources for generating machine code from your design. Native program execution is the only way for high speed simulation.
Partial support of PSL.
GHDL runs on GNU/Linux, Windows and macOS; on
ppc64. You can freely download nightly assets, use OCI images (aka Docker/Podman containers), or try building it on your own machine (see 'Getting GHDL' below).
Co-simulation with foreign applications is supported through Verilog Procedural Interface (VPI) and/or VHPIDIRECT. See ghdl.github.io/ghdl-cosim.
Can synthesize arbitrarily complex VHDL designs into a VHDL 1993 netlist, which can be implicitly or explicitly used in open source or vendor synthesis frameworks.
GHDL is free software:
- available at ghdl.github.io/ghdl.
- Some of the runtime libraries, are under different terms; see the individual source files for details.
- Pre-built packages:
- GHDL is available through the default package manager on most distributions: Debian/Ubuntu, Fedora, Arch Linux, MSYS2, etc.
- After each succesful CI run, nightly tarballs/zipfiles for Ubuntu and Windows (MSYS2) are updated.
- For using GHDL in CI, setup-ghdl-ci is provided. It is a GitHub Action (see github.com/features/actions) to setup GHDL in just 3 lines.
- You may use containers from ghdl/docker or hdl/containers, in case your didn't find a suitable release.
- Build GHDL yourself! See ghdl.github.io/ghdl: Building GHDL.
The CLI tool allows analysis, compilation, simulation and (experimental) synthesis for generating VHDL 1993 netlists. It is written in Ada and C, and three different backends are supported, which are sometimes named
ghdl_llvm. This is the entrypoint for most users.
ghdl-ls(part of pyGHDL, see below) implements Language Server Protocol (LSP) in Python. VHDL analysis features provided by GHDL are accessed through
libghdl. This can be integrated in text editors or IDES, such as, Vim, Emacs, Atom or Visual Studio Code. See ghdl/ghdl-language-server.
libghdlis a shared library that includes a subset of the regular features plus some features to be used by extension tools (i.e.
pyGHDL). This is built along with the regular GHDL and it supports both non-synthesisable and synthesisable code. Nonetheless, this is not for users, but for tools built on top of the core. When configured along with
--enable-synth, this shared library includes synthesis features too.
pyGHDL is a Python interface to
libghdl. Currently, it is only used by
ghdl-ls; however, it can be useful for advanced users which are willing to build Python utilities based on GHDL. There is work in progress for binding libghdl to pyVHDLModel (see
ghdl_simul, which supports interpreted simulation, is available for historical reasons and for development/debugging only. It is very slow compared to the 'regular' compiled simulation and not all the features are supported.