Initialise ie to -1

Author: robtaylor

chipflow_lib/platforms/silicon.py

@@ -94,7 +94,7 @@ def __init__(self,
         # Create signals based on direction
         if self.direction in (io.Direction.Input, io.Direction.Bidir):
             self._i = Signal(width, name=f"{self._name}$i")
-            self._ie = Signal(width, name=f"{self._name}$ie")
+            self._ie = Signal(width, name=f"{self._name}$ie", init=-1)
         if self.direction in (io.Direction.Output, io.Direction.Bidir):
             self._o = Signal(width, name=f"{self._name}$o")