Adapting GCD to Learning Journey

*.original

*.inProgress

// See LICENSE.txt for license details.

// January 20th, 2018	- adapted to Learning Journey

package examples

import chisel3._

import Chisel._ 

class GCD extends Module { 

  val io = IO(new Bundle {

    val a  = Input(UInt(16.W))

    val b  = Input(UInt(16.W))

    val e  = Input(Bool())

    val z  = Output(UInt(16.W))

    val v  = Output(Bool())

  })

  val io = new Bundle { 

    val a  = UInt(INPUT,  16) 

    val b  = UInt(INPUT,  16) 

    val e  = Bool(INPUT) 

    val z  = UInt(OUTPUT, 16) 

    val v  = Bool(OUTPUT) 

  } 

  val x  = Reg(UInt()) 

  val y  = Reg(UInt()) 

  when   (x > y) {

    x := x - y

  }

    .elsewhen (x <= y) { y := y - x }

  when   (x > y) { x := x - y } 

  unless (x > y) { y := y - x } 

  when (io.e) { x := io.a; y := io.b } 

  io.z := x 

  io.v := y === 0.U

  io.v := y === UInt(0) 

}