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new 0.10.0 May 10, 2024
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0.5.6 Oct 19, 2023
0.1.3 Dec 23, 2022

#1268 in Hardware support

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Used in 6 crates


50K SLoC


Actions Status Crates.io Changelog

Veryl is a modern hardware description language.

This project is under the exploration phase of language design. If you have any idea, please open Issue.


Veryl is a hardware description language based on SystemVerilog, providing the following advantages:

Optimized Syntax

Veryl adopts syntax optimized for logic design while being based on a familiar basic syntax for SystemVerilog experts. This optimization includes guarantees for synthesizability, ensuring consistency between simulation results, and providing numerous syntax simplifications for common idioms. This approach enables ease of learning, improves the reliability and efficiency of the design process, and facilitates ease of code writing.


Designed with interoperability with SystemVerilog in mind, Veryl allows smooth integration and partial replacement with existing SystemVerilog components and projects. Furthermore, SystemVerilog source code transpiled from Veryl retains high readability, enabling seamless integration and debugging.


Veryl comes with a rich set of development support tools, including package managers, build tools, real-time checkers compatible with major editors such as VSCode, Vim, Emacs, automatic completion, and automatic formatting. These tools accelerate the development process and significantly enhance productivity.

With these features, Veryl provides powerful support for designers to efficiently and productively conduct high-quality hardware design.


Veryl SystemVerilog
/// documentation comment by markdown format
/// * list item1
/// * list item2
pub module Delay #( // visibility control by `pub` keyword
    param WIDTH: u32 = 1, // trailing comma is allowed
) (
    i_clk : input clock       ,
    i_rst : input reset       ,
    i_data: input logic<WIDTH>,
    o_data: input logic<WIDTH>,
) {
    // unused variable which is not started with `_` are warned
    var _unused_variable: logic;

    always_ff (i_clk, i_rst) {
        // abstraction syntax of reset polarity and synchronicity
        if_reset {
            o_data = '0;
        } else {
            o_data = i_data;
// comment
module Delay #(
    parameter int WIDTH = 1
) (
    input              i_clk ,
    input              i_rst ,
    input  [WIDTH-1:0] i_data,
    output [WIDTH-1:0] o_data
    logic unused_variable;

    always_ff @ (posedge i_clk or negedge i_rst) begin
        if (!i_rst) begin
            o_data <= '0;
        end else begin
            o_data <= i_data;


See Document.


// Create a new project
veryl new [project name]

// Create a new project in an existing directory
veryl init [path]

// Format the current project
veryl fmt

// Analyze the current project
veryl check

// Build target codes corresponding to the current project
veryl build

// Build the document corresponding to the current project
veryl doc

For detailed information, see Document.


Licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


~855K SLoC