1 files changed, 62 insertions, 0 deletions
diff --git a/src/test/scala/ChiselTests/Stack.scala b/src/test/scala/ChiselTests/Stack.scala
new file mode 100644
index 00000000..afcbc8bc
--- /dev/null
+++ b/src/test/scala/ChiselTests/Stack.scala
@@ -0,0 +1,62 @@
+package ChiselTests
+import scala.collection.mutable.{Stack => ScalaStack}
+import Chisel._
+
+class Stack(val depth: Int) extends Module {
+  val io = new Bundle {
+    val push    = Bool(INPUT)
+    val pop     = Bool(INPUT)
+    val en      = Bool(INPUT)
+    val dataIn  = UInt(INPUT,  32)
+    val dataOut = UInt(OUTPUT, 32)
+  }
+
+  val stack_mem = Mem(UInt(width = 32), depth)
+  val sp        = Reg(init = UInt(0, width = log2Up(depth+1)))
+  val out       = Reg(init = UInt(0, width = 32))
+
+  when (io.en) {
+    when(io.push && (sp < UInt(depth))) {
+      stack_mem(sp) := io.dataIn
+      sp := sp +% UInt(1)
+    } .elsewhen(io.pop && (sp > UInt(0))) {
+      sp := sp -% UInt(1)
+    }
+    when (sp > UInt(0)) {
+      out := stack_mem(sp -% UInt(1))
+    }
+  }
+  io.dataOut := out
+}
+
+class StackTester(c: Stack) extends Tester(c) {
+  var nxtDataOut = 0
+  var dataOut = 0
+  val stack = new ScalaStack[Int]()
+
+  for (t <- 0 until 16) {
+    val enable  = rnd.nextInt(2)
+    val push    = rnd.nextInt(2)
+    val pop     = rnd.nextInt(2)
+    val dataIn  = rnd.nextInt(256)
+
+    if (enable == 1) {
+      dataOut = nxtDataOut
+      if (push == 1 && stack.length < c.depth) {
+        stack.push(dataIn)
+      } else if (pop == 1 && stack.length > 0) {
+        stack.pop()
+      }
+      if (stack.length > 0) {
+        nxtDataOut = stack.top
+      }
+    }
+
+    poke(c.io.pop,    pop)
+    poke(c.io.push,   push)
+    poke(c.io.en,     enable)
+    poke(c.io.dataIn, dataIn)
+    step(1)
+    expect(c.io.dataOut, dataOut)
+  }
+}