Merge pull request #89 from ucb-bar/when

Fix when / elsewhen / otherwise behavior and add unit test

1 files changed, 60 insertions, 0 deletions

diff --git a/src/test/scala/chiselTests/When.scala b/src/test/scala/chiselTests/When.scala
new file mode 100644
index 00000000..b78e1c5a
--- /dev/null
+++ b/src/test/scala/chiselTests/When.scala
@@ -0,0 +1,60 @@
+// See LICENSE for license details.
+
+package chiselTests
+
+import org.scalatest._
+import Chisel._
+import Chisel.testers.BasicTester
+
+class WhenTester() extends BasicTester {
+  val cnt = Counter(4)
+  when(Bool(true)) { cnt.inc() }
+
+  val out = Wire(UInt(width=3))
+  when(cnt.value === UInt(0)) {
+    out := UInt(1)
+  } .elsewhen (cnt.value === UInt(1)) {
+    out := UInt(2)
+  } .elsewhen (cnt.value === UInt(2)) {
+    out := UInt(3)
+  } .otherwise {
+    out := UInt(0)
+  }
+
+  assert(out === cnt.value + UInt(1))
+
+  when(cnt.value === UInt(3)) {
+    stop()
+  }
+}
+
+class OverlappedWhenTester() extends BasicTester {
+  val cnt = Counter(4)
+  when(Bool(true)) { cnt.inc() }
+
+  val out = Wire(UInt(width=3))
+  when(cnt.value <= UInt(0)) {
+    out := UInt(1)
+  } .elsewhen (cnt.value <= UInt(1)) {
+    out := UInt(2)
+  } .elsewhen (cnt.value <= UInt(2)) {
+    out := UInt(3)
+  } .otherwise {
+    out := UInt(0)
+  }
+
+  assert(out === cnt.value + UInt(1))
+
+  when(cnt.value === UInt(3)) {
+    stop()
+  }
+}
+
+class WhenSpec extends ChiselFlatSpec {
+  "When, elsewhen, and otherwise with orthogonal conditions" should "work" in {
+    assert(execute{ new WhenTester })
+  }
+  "When, elsewhen, and otherwise with overlapped conditions" should "work" in {
+    assert(execute{ new OverlappedWhenTester })
+  }
+}