Masks for zero-width fields of mems should be width zero. (#763)

Closes #666.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/main/scala/firrtl/passes/memlib/MemUtils.scala b/src/main/scala/firrtl/passes/memlib/MemUtils.scala
index 40f81555..709e57af 100644
--- a/src/main/scala/firrtl/passes/memlib/MemUtils.scala
+++ b/src/main/scala/firrtl/passes/memlib/MemUtils.scala
@@ -46,6 +46,7 @@ object createMask {
   def apply(dt: Type): Type = dt match {
     case t: VectorType => VectorType(apply(t.tpe), t.size)
     case t: BundleType => BundleType(t.fields map (f => f copy (tpe=apply(f.tpe))))
+    case GroundType(w) if w == IntWidth(0) => UIntType(IntWidth(0))
     case t: GroundType => BoolType
   }
 }