Chisel 語言學習 2 例項化模型和向量操作

系列文章主要用來記錄學習Chisel和scala過程中遇到的難點或知識點

例項化模型：

帶有進位的加法器

Chisel程式碼如下：

// A 4-bit adder with carry in and carry out
class Adder4 extends Module {
  val io = IO(new Bundle {
    val A    = Input(UInt(4.W))
    val B    = Input(UInt(4.W))
    val Cin  = Input(UInt(1.W))
    val Sum  = Output(UInt(4.
 
W))
    val Cout = Output(UInt(1.W))
  })
  // Adder for bit 0
  val Adder0 = Module(new FullAdder())
  Adder0.io.a   := io.A(0)
  Adder0.io.b   := io.B(0)
  Adder0.io.cin := io.Cin
  val s0 = Adder0.io.sum
  // Adder for bit 1
  val Adder1 = Module(new FullAdder())
  Adder1.io.a   := io.A(1)
  Adder1.io.b   := io.B
 
(1)
  Adder1.io.cin := Adder0.io.cout
  val s1 = Cat(Adder1.io.sum, s0)
  // Adder for bit 2
  val Adder2 = Module(new FullAdder())
  Adder2.io.a   := io.A(2)
  Adder2.io.b   := io.B(2)
  Adder2.io.cin := Adder1.io.cout
  val s2 = Cat(Adder2.io.sum, s1)
  // Adder for bit 3
  val Adder3 = Module(new FullAdder())
  Adder3.io
 
.a   := io.A(3)
  Adder3.io.b   := io.B(3)
  Adder3.io.cin := Adder2.io.cout
  io.Sum  := Cat(Adder3.io.sum, s2).asUInt
  io.Cout := Adder3.io.cout
}

向量操作

val myVec = Vec(Seq.fill( <number of elements> ) { <data type> })

eg:

val ufix5_vec10 := Vec(Seq.fill(10) { UInt(5.W) })

定義一個向量暫存器：

val reg_vec32 = Reg(Vec(Seq.fill(32){ UInt() }))

定義一個16位加法器（向量的值包含例項時，我們用io來定義）：

val FullAdders = 
  Vec(Seq.fill(16){ Module(new FullAdder()).io })

為了使程式碼簡潔，我們可以用下面這種寫法：

val initValues = Seq.fill(4) { 0.U(8.W) }
  val delays = RegInit(Vec(initValues))