Personal tools


From HaskellWiki

Jump to: navigation, search
Project: CλaSH
Description: Functional hardware description language
CλaSH Liaison: Richard Tobias

1 What is CλaSH

CλaSH (pronounced ‘clash’) is a functional hardware description language that borrows both its syntax and semantics from the functional programming language Haskell. It provides a familiar structural design approach to both combinational and synchronous sequential circuits. The CλaSH compiler transforms these high-level descriptions to low-level synthesizable VHDL, Verilog, or SystemVerilog.

Features of CλaSH:

  • 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.
  • Compile your designs for fast simulation.
  • Higher-order functions, in combination 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.
  • Multiple clock domains, with type safe clock domain crossing.
  • Template language for introducing new VHDL/(System)Verilog primitives.

From the CλaSH website

2 CλaSH Project Ideas

Christiaan Baaij, one of the principle creators of CλaSH gave these ideas for hackathon projects:

A project that I'm think about is:

  • To get a decent build system for CλaSH that includes regression testing with a verilog simulator and calling the appropriate EDA tools from either Altera or Xilinx to synthesize, place and route and then download the bitfile to the FPGA itself. A good starting point for this is the build system that Austin Seipp created in his claap project. You can find this build system inside of his project at

3 Good FPGA Boards to Bring to BayHac2017 CλaSH Hackathon

I will bring a few DE0-nano boards to the hackathon. They are quite inexpensive and can be purchased for about $85 on DigiKey, adafruit and other locations on the web.

A good list of boards can be found here:

The list is copied here (thanks goes to darchon on the subreddit for haskell):