具有多时钟域的凿子测试器

试着测试asyncFifo用这样的StephedHwiotester在凿子中编写的代码

class AsyncFifo(width: Int, depth: Int, syncStages: Int) extends Module {
  val length = log2Ceil(depth)
  val io = IO(new Bundle {
    val clk_write = Input(Clock())
    val clk_read = Input(Clock())
    val rstn_write = Input(Bool())
    val rstn_read = Input(Bool())
    val deq = Decoupled(UInt(width.W))
    val enq = Flipped(Decoupled(UInt(width.W)))
  })
  val memory = Mem(depth, UInt(width.W))
  val reader: reader = withClock(io.clk_read)( Module(new reader(width, depth, syncStages)) )
  val writer: writer = withClock(io.clk_write)( Module(new writer(width, depth, syncStages)) )
  //some connections here...
}
class AsyncFifoHardWareTester extends SteppedHWIOTester {
  val device_under_test = Module(new AsyncFifo(32, 32, 2))
  val c = device_under_test
  enable_all_debug = true

  step(2)
  poke(c.io.enq.bits, 0x11L)
  poke(c.io.enq.valid, 0x1L)
  step(2)
  poke(c.io.enq.bits, 0x11L)
  poke(c.io.enq.valid, 0x0L)
  step(2)
  expect(c.io.deq.valid, 0x11L)
  expect(c.io.deq.bits, 0x0L)
}

测试仪生成vcd,其中clk_写入和clk_读取由零驱动。