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
Signal
s, 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: functionalprogramming.slack.com#clash (Invite yourself at fpslack.com/).
IRC: libera.chat#clash (webchat access) (or ircs://irc.libera.chat:6697/clash if you want to use a regular IRC client)
Check out clash-lang.org/install to install the latest stable release of Clash, or to setup a Clash project.
Get the source code using Git and enter the cloned directory:
git clone [email protected]:clash-lang/clash-compiler.git
# Alternatively, if you haven't setup SSH keys with GitHub:
# git clone https://github.com/clash-lang/clash-compiler.git
cd clash-compiler
To check out a released version, use:
git checkout v1.2.3
To checkout a release branch use:
git checkout 1.2
Note that release branches might contain non-released patches.
Linux | Windows | macOS | |
---|---|---|---|
8.6 | ✔️ | ✔️ | ✔️ |
8.8 | ✔️ | ❌ | ✔️ |
8.10 | ✔️ | ✔️ | ❌ |
9.0 | ✔️ | ✔️² | ✔️ |
9.2¹ | ❌ | ❌ | ❌ |
9.4³ | ❌ | ❌ | ❌ |
¹ GHC 9.2 contains a regression, rendering Clash error messages indecipherable. This change will be reverted in 9.4.
² GHC 9.0.2 on Windows fails to compile clash-cores
. We therefore don't run the Clash testsuite on CI for this combination.
³ A critical dependency of Clash, hint
, has not yet been ported to GHC 9.4.
To use Cabal you need both Cabal and GHC installed on your system. We recommend using ghcup. For more information, see https://www.haskell.org/downloads/.
To run clash
use:
cabal v2-run -- clash
If this fails, make sure you've got an up-to-date package index:
cabal update
Install Stack and run:
stack run -- clash
Or use Nix to get a shell with the clash
and clashi
binaries on your PATH:
nix-shell
- Clashilator: tooling to integrate Clash with Verilator. Enables fast, multithreaded simulation by compiling Clash designs to C++.
- Clash Protocols: experimental library for writing Clash circuits with bidirectional communication - such as AXI or Avalon.
- Clash Starters: starter projects to quickly get you up and running.
- Clash WaveDrom: generate wave diagrams from Clash using WaveDrom
- Contranomy: a RISCV implementation verified using the RISC-V Formal Verification Framework.
- Space Invaders: a Clash implementation of the 1978 Space Invaders arcade machine by Taito.