backend/regfile/Regfile.scala

package xiangshan.backend.regfile

import chisel3._
import chisel3.util._
import xiangshan._

class RfReadPort extends XSBundle {
  val addr = Input(UInt(PhyRegIdxWidth.W))
  val data = Output(UInt(XLEN.W))
}

class RfWritePort extends XSBundle {
  val wen = Input(Bool())
  val addr = Input(UInt(PhyRegIdxWidth.W))
  val data = Input(UInt(XLEN.W))
}

class Regfile
(
  numReadPorts: Int,
  numWirtePorts: Int,
  hasZero: Boolean
) extends XSModule {
  val io = IO(new Bundle() {
    val readPorts = Vec(numReadPorts, new RfReadPort)
    val writePorts = Vec(numWirtePorts, new RfWritePort)
  })

  val mem = Mem(NRPhyRegs, UInt(XLEN.W))

  for(r <- io.readPorts){
    val addr_reg = RegNext(r.addr)
    r.data := {if(hasZero) Mux(addr_reg===0.U, 0.U, mem(addr_reg)) else mem(addr_reg)}
  }

  for(w <- io.writePorts){
    when(w.wen){
      mem(w.addr) := w.data
    }
  }
}