diff --git a/src/main/scala/util/PSDTestMode.scala b/src/main/scala/util/PSDTestMode.scala
new file mode 100644
index 00000000..ae4a3942
--- /dev/null
+++ b/src/main/scala/util/PSDTestMode.scala
@@ -0,0 +1,19 @@
+// See LICENSE.SiFive for license details.
+
+package freechips.rocketchip.util
+
+import Chisel._
+import freechips.rocketchip.config._
+
+case object IncludePSDTest extends Field[Boolean](false)
+
+class PSDTestModeIO extends Bundle {
+  val test_mode       = Bool(INPUT)
+  val test_mode_reset = Bool(INPUT)
+  // TODO: Clocks?
+}
+
+trait CanHavePSDTestModeIO {
+  implicit val p: Parameters
+  val psd = p(IncludePSDTest).option(new PSDTestModeIO())
+}