diff --git a/himbaechel/uarch/xilinx/fasm.cc b/himbaechel/uarch/xilinx/fasm.cc
index f59a3fe4..8d31b6bd 100644
--- a/himbaechel/uarch/xilinx/fasm.cc
+++ b/himbaechel/uarch/xilinx/fasm.cc
@@ -322,8 +322,6 @@ struct FasmBackend
                             src_name.replace(us0pos, 2, "_1");
                     }
                 }
-
-                NPNR_ASSERT_FALSE("unimplemented!");
             }
             if (boost::contains(tile_name, "IOI")) {
                 if (boost::contains(dst_name, "OCLKB") && boost::contains(src_name, "IOI_OCLKM_"))