diff --git a/modules/common/gc_sync_ffs.vhd b/modules/common/gc_sync_ffs.vhd
index e49ada0dbc2dbdaa495283f2184bd46d3546e91b..3b6fafbfd8fb57ce8b36d37ad83994bf29c4c6f1 100644
--- a/modules/common/gc_sync_ffs.vhd
+++ b/modules/common/gc_sync_ffs.vhd
@@ -7,6 +7,7 @@
 -- unit name:   gc_sync_ffs
 --
 -- description: Synchronizer chain and edge detector.
+--   All the registers in the chain are cleared at reset.
 --
 --------------------------------------------------------------------------------
 -- Copyright CERN 2010-2018