About Chisel

Chisel is a new open-source hardware construction language developed at UC Berkeley that supports advanced hardware design using highly parameterized generators and layered domain-specific hardware languages.

Chisel is embedded in the Scala programming language, which raises the level of hardware design abstraction by providing concepts including object orientation, functional programming, parameterized types, and type inference.

Chisel can generate a high-speed C++-based cycle-accurate software simulator, or low-level Verilog designed to pass on to standard ASIC or FPGA tools for synthesis and place and route.

Visit the community website for more information.

Getting started

Chisel Users

To start working on a circuit with Chisel, create a project directory with a standard Scala/SBT layout. You want your build.sbt file to contain a reference to Scala version greater or equal to 2.10 and add a dependency on the Chisel library.

$ cat build.sbt
scalaVersion := "2.10.2"

resolvers ++= Seq(
    "Sonatype Snapshots" at "http://oss.sonatype.org/content/repositories/snapshots",
    "Sonatype Releases" at "http://oss.sonatype.org/content/repositories/releases"
)

libraryDependencies += "edu.berkeley.cs" %% "chisel" % "2.0-SNAPSHOT"

Edit the source files for your circuit

$ cat Hello.scala
import Chisel._

class HelloModule extends Module {

    val io = new Bundle {}

    printf("Hello World!\n")
}

class HelloModuleTests(c: HelloModule) extends Tester(c, Array(c.io)) {
    defTests {
        true
    }
}

object hello {
    def main(args: Array[String]): Unit = {
        chiselMainTest(Array[String]("--backend", "c", "--genHarness"),
            () => Module(new HelloModule())){c => new HelloModuleTests(c)}
    }
}

Execute sbt run to generate the C++ simulation source for your circuit

$ sbt run

Compile the resulting C++ output to generate a simulation executable

$ g++ -std=c++11 -o HelloModule HelloModule.cpp HelloModule-emulator.cpp

Run the simulation executable for one clock cycle to generate a simulation trace

$ ./HelloModule 1
Hello World!

Chisel developpers

Checking coding style compliance

$ sbt scalastyle

Running unit tests with code coverage

$ sbt scct:test

Publishing jar to local system

$ sbt publish-local

Publishing to public Maven repo

$ sbt publish-signed