Clash is a functional hardware description language that borrows both its syntax and semantics from the functional programming language Haskell. The Clash compiler transforms these high-level descriptions to low-level synthesizable VHDL, Verilog, or SystemVerilog.

Features of Clash:

• Strongly typed, but with a very high degree of type inference, enabling both safe and fast prototyping using concise descriptions.

• Interactive REPL: load your designs in an interpreter and easily test all your component without needing to setup a test bench.

• Higher-order functions, with type inference, result in designs that are fully parametric by default.

• Synchronous sequential circuit design based on streams of values, called Signals, lead to natural descriptions of feedback loops.

• Support for multiple clock domains, with type safe clock domain crossing.

Mailing list: for updates and questions join the mailing list [email protected] or read the forum

Slack: Invite yourself at fpchat-invite.herokuapp.com. To join #clash, click on "Channels" and search for "clash".

IRC: freenode#clash-lang

Clone Clash from github using git and enter the cloned directory:

git clone https://github.com/clash-lang/clash-compiler.git
cd clash-compiler

Use one of the build tools below to get Clash up and running.

Install Cabal >= 2.4 and GHC >= 8.4. Even though GHC 8.6 is supported, we currently recommend running 8.4 as the former contains some known bugs concerning documentation generation. If you're using Ubuntu, add HVR's PPA and install them using APT:

sudo add-apt-repository -u ppa:hvr/ghc
sudo apt install ghc-8.4.4 cabal-install-2.4

Add /opt/ghc/bin to your PATH. Finally, run Clash using cabal:

cabal new-run --write-ghc-environment-files=always -- clash

You can use Stack to build and run Clash too:

stack run -- clash

Or use Nix to get a shell with the clash and clashi binaries on your PATH:

nix-shell