Dual clock fifo
===============

.. code-block:: scala

   //Compile the simulator
   val compiled = SimConfig.withWave.allOptimisation.compile(
     rtl = new StreamFifoCC(
       dataType = Bits(32 bits),
       depth = 32,
       pushClock = ClockDomain.external("clkA"),
       popClock = ClockDomain.external("clkB")
     )
   )

   //Run the simulation
   compiled.doSimUntilVoid{dut =>
     val queueModel = mutable.Queue[Long]()

     //Fork a thread to manage the clock domains signals
     val clocksThread = fork{
       //Clear clock domains signals, to be sure the simulation capture their first edge.
       dut.pushClock.fallingEdge()
       dut.popClock.fallingEdge()
       dut.pushClock.deassertReset()
       dut.popClock.deassertReset()
       sleep(0)

       //Do the resets
       dut.pushClock.assertReset()
       dut.popClock.assertReset()
       sleep(10)
       dut.pushClock.deassertReset()
       dut.popClock.deassertReset()
       sleep(1)

       //Forever, randomly toggle one of the clocks (will create asynchronous clocks without fixed frequencies)
       while(true){
         if(Random.nextBoolean()) {
           dut.pushClock.clockToggle()
         } else {
           dut.popClock.clockToggle()
         }
         sleep(1)
       }
     }

     //Push data randomly and fill the queueModel with pushed transactions
     val pushThread = fork{
       while(true){
         dut.io.push.valid.randomize()
         dut.io.push.payload.randomize()
         dut.pushClock.waitSampling()
         if(dut.io.push.valid.toBoolean && dut.io.push.ready.toBoolean){
           queueModel.enqueue(dut.io.push.payload.toLong)
         }
       }
     }

     //Pop data randomly and check that it match with the queueModel
     val popThread = fork{
       for(i <- 0 until 100000){
         dut.io.pop.ready.randomize()
         dut.popClock.waitSampling()
         if(dut.io.pop.valid.toBoolean && dut.io.pop.ready.toBoolean){
           assert(dut.io.pop.payload.toLong == queueModel.dequeue())
         }
       }
       simSuccess()
     }
   }