Chisel (programming language)
Open-source hardware description language (HDL)
Chisel (an acronym for Constructing Hardware in a Scala Embedded Language) is an open-source hardware description language (HDL) used to describe digital electronics and circuits at the register-transfer level.
Chisel is based on Scala as a domain-specific language (DSL). Chisel inherits the object-oriented and functional programming aspects of Scala for describing digital hardware. Using Scala as a basis allows describing circuit generators. High quality, free access documentation exists in several languages.
Circuits described in Chisel can be converted to a description in Verilog for synthesis and simulation.
01Code examples
A simple example describing an adder circuit and showing the organization of components in Module with input and output ports:
class Add extends Module { val io = IO(new Bundle { val a = Input(UInt(8.W)) val b = Input(UInt(8.W)) val y = Output(UInt(8.W)) }) io.y := io.a + io.b }A 32-bit register with a reset value of 0:
val reg = RegInit(0.U(32.W))A multiplexer is part of the Chisel library:
val result = Mux(sel, a, b)02Use
Although Chisel is not yet a mainstream hardware description language, it has been explored by several companies and institutions. The most prominent use of Chisel is an implementation of the RISC-V instruction set, the open-source Rocket chip. Chisel is mentioned by the Defense Advanced Research Projects Agency (DARPA) as a technology to improve the efficiency of electronic design, where smaller design teams do larger designs. Google has used Chisel to develop a Tensor Processing Unit for edge computing. Some developers prefer Chisel as it requires one-fifth as much code and is much faster to develop than Verilog.
Circuits described in Chisel can be converted to a description in Verilog for synthesis and simulation using a program named FIRRTL.
Sources and credits
This article is adapted from the Wikipedia article “Chisel (programming language)”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.
