fhdl/autofragment: fix submodules

diff --git a/migen/fhdl/autofragment.py b/migen/fhdl/autofragment.py
index 413b9d82fb2ad9eddaf21f69f5a8434bb58c18bb..4ff36086d77434bfa8c60f3f41a26f65a00ae80f 100644 (file)
--- a/migen/fhdl/autofragment.py
+++ b/migen/fhdl/autofragment.py
@@ -91,7 +91,7 @@ class FModule:
                if hasattr(self, "do_simulation"):
                        self._fragment.sim.append(self.do_simulation)
                for submodule in self._submodules:
-                       f += submodule.get_fragment()
+                       self._fragment += submodule.get_fragment()
                if self.auto_attr:
                        for x in self.__dict__.values():
                                if isinstance(x, Special):