#Yellowspec is a library which provide Bluespec-like expression for hardward based on chisel3. Just as Bluespec (a High-level Hardware Design Language), #Yellowspec using Rules and Methods to express synthesizable behavior, which are more powerful and abstract ways for data-driven circuit than always blocks and ports.
Yellowspec is a library providing software-like interface definitions and bindings for Module in chisel3.
Yellowspec using Rules and Methods to express synthesizable behavior, which are more powerful and abstract ways for data-driven circuit than always blocks and ports in chisel. Method is the abstraction of the Module's interface and combinational logic behavior,simular to function definition in software. Rule is used to express sequencial logic , and can call Method in a way simular to function call.
Consider a module : read numbers from outside the module, multiply it by 2 and put the result to the queue.When needed,write out the results.
The code using Yellowspec is like this:
class Mult2(depth: Int) extends Module with Yellowspec {
val io = IO(new Bundle {
// declare a method Mult2 own
val deq = ActionMethodIO(Void, UInt(8.W))
// declare a method Mult2 use
val enq = Flipped(ActionMethodIO(Void, UInt(8.W)))
})
val queue = Reg(Vec(depth, UInt(8.W)))
val headPointer = Reg(UInt(3.W))
val tailPointer = Reg(UInt(3.W))
// bind io.deq to a method , which take a number from queue and return if queue is not empty
io.deq := ActionMethod(headPointer =/= tailPointer) {
(params:Void) => {
tailPointer := tailPointer + 1.U
queue(tailPointer)
}
}
// when the rule queue is not full , read a number , multiply it by 2 and put it in to the queue
rule(headPointer =/= tailPointer - 1.U) {
headPointer := headPointer + 1.U
queue(headPointer) := io.enq(Void) * 2.U
}
}
#Module Mult2 has 2 methods : Enq ,deq. Method enq is called by Mult2 , providng data that Mult2 needs.
As you can see, instead of ports and when , this Module using method and rule.
Clone this repo into a directory , then build and publish to your cache
git clone https://github.com/cxzzzz/Yellowspec.git
cd Yellowspec
sbt "publishLocal"Add dependencies into your project's build.sbt:
libraryDependencies += "org.cxzzzz" %% "yellowspec" % "0.+"