def _clean(self, rmConnetions=True, lockNonExternal=True):
        """
        Remove all signals from this interface (used after unit is synthesized
        and its parent is connecting its interface to this unit)
        """

        if self._interfaces:
            for i in self._interfaces:
                i._clean(rmConnetions=rmConnetions,
                         lockNonExternal=lockNonExternal)
        else:
            self._sigInside = self._sig
            del self._sig

        if lockNonExternal and not self._isExtern:
            self._isAccessible = False