Module Hierarchy Refactor (#469)

1 files changed, 58 insertions, 0 deletions

diff --git a/src/test/scala/chiselTests/MultiIOModule.scala b/src/test/scala/chiselTests/MultiIOModule.scala
new file mode 100644
index 00000000..07e09041
--- /dev/null
+++ b/src/test/scala/chiselTests/MultiIOModule.scala
@@ -0,0 +1,58 @@
+// See LICENSE for license details.
+
+package chiselTests
+
+import chisel3._
+import chisel3.experimental.MultiIOModule
+import chisel3.testers.BasicTester
+
+class MultiIOPlusOne extends MultiIOModule {
+  val in  = IO(Input(UInt(32.W)))
+  val out = IO(Output(UInt(32.W)))
+
+  out := in + 1.asUInt
+}
+
+class MultiIOTester extends BasicTester {
+  val plusModule = Module(new MultiIOPlusOne)
+  plusModule.in := 42.U
+  assert(plusModule.out === 43.U)
+  stop()
+}
+
+// Demonstrate multiple IOs with inheritance where the IO is assigned to internally
+trait LiteralOutputTrait extends MultiIOModule {
+  val myLiteralIO = IO(Output(UInt(32.W)))
+  myLiteralIO := 2.U
+}
+
+// Demonstrate multiple IOs with inheritance where the IO is not assigned
+// (and must be assigned by what extends this trait).
+trait MultiIOTrait extends MultiIOModule {
+  val myTraitIO = IO(Output(UInt(32.W)))
+}
+
+// Composition of the two above traits, example of IO composition directly using multiple top-level
+// IOs rather than indirectly by constraining the type of the single .io field.
+class ComposedMultiIOModule extends MultiIOModule 
+    with LiteralOutputTrait with MultiIOTrait {
+  val topModuleIO = IO(Input(UInt(32.W)))
+  myTraitIO := topModuleIO
+}
+
+class ComposedMultiIOTester extends BasicTester {
+  val composedModule = Module(new ComposedMultiIOModule)
+  composedModule.topModuleIO := 42.U
+  assert(composedModule.myTraitIO === 42.U)
+  assert(composedModule.myLiteralIO === 2.U)
+  stop()
+}
+
+class MultiIOSpec extends ChiselFlatSpec {
+  "Multiple IOs in MultiIOModule" should "work" in {
+    assertTesterPasses({ new MultiIOTester })
+  }
+  "Composed MultiIO Modules" should "work" in {
+    assertTesterPasses({ new ComposedMultiIOTester })
+  }
+}