make unit test debug output more meaningful

groundtest/src/main/scala/unittests/Main.scala

@@ -15,6 +15,10 @@ abstract class UnitTest extends Module {
     val finished = Bool(OUTPUT)
     val start = Bool(INPUT)
   }
+
+  when (io.start) {
+    printf(s"Started UnitTest ${this.getClass.getName}\n")
+  }
 }
 
 case object UnitTests extends Field[Parameters => Seq[UnitTest]]
@@ -22,22 +26,30 @@ case object UnitTests extends Field[Parameters => Seq[UnitTest]]
 class UnitTestSuite(implicit p: Parameters) extends GroundTest()(p) {
   val tests = p(UnitTests)(p)
 
-  val s_idle :: s_start :: s_wait :: Nil = Enum(Bits(), 3)
+  val s_idle :: s_start :: s_wait :: s_done :: Nil = Enum(Bits(), 4)
   val state = Reg(init = s_idle)
+  val test_idx = Reg(init = UInt(0, log2Up(tests.size)))
+  val test_finished = Vec(tests.map(_.io.finished))
 
   when (state === s_idle) { state := s_start }
   when (state === s_start) { state := s_wait }
+  when (state === s_wait && test_finished(test_idx)) {
+    state := s_start
+    test_idx := test_idx + UInt(1)
+    state := Mux(test_idx === UInt(tests.size - 1), s_done, s_start)
+  }
 
   io.status.timeout.valid := Bool(false)
   tests.zipWithIndex.foreach { case (mod, i) =>
-    mod.io.start := (state === s_start)
+    mod.io.start := (state === s_start) && test_idx === UInt(i)
     val timeout = Timer(1000, mod.io.start, mod.io.finished)
-    assert(!timeout, s"UnitTest $i timed out")
+    assert(!timeout, s"UnitTest ${mod.getClass.getName} timed out")
     when (timeout) {
       io.status.timeout.valid := Bool(true)
       io.status.timeout.bits := UInt(i)
     }
   }
-  io.status.finished := tests.map(_.io.finished).reduce(_ && _)
+  io.status.finished := (state === s_done)
   io.status.error.valid := Bool(false)
+
 }