1 files changed, 19 insertions, 0 deletions
diff --git a/src/main/scala/chisel3/util/Lookup.scala b/src/main/scala/chisel3/util/Lookup.scala
new file mode 100644
index 00000000..d32d9aec
--- /dev/null
+++ b/src/main/scala/chisel3/util/Lookup.scala
@@ -0,0 +1,19 @@
+// See LICENSE for license details.
+
+package chisel.util
+
+import chisel._
+
+object ListLookup {
+  def apply[T <: Data](addr: UInt, default: List[T], mapping: Array[(BitPat, List[T])]): List[T] = {
+    val map = mapping.map(m => (m._1 === addr, m._2))
+    default.zipWithIndex map { case (d, i) =>
+      map.foldRight(d)((m, n) => Mux(m._1, m._2(i), n))
+    }
+  }
+}
+
+object Lookup {
+  def apply[T <: Bits](addr: UInt, default: T, mapping: Seq[(BitPat, T)]): T =
+    ListLookup(addr, List(default), mapping.map(m => (m._1, List(m._2))).toArray).head
+}