diff --git a/litedram/frontend/axi.py b/litedram/frontend/axi.py
index 50a8234..29190b4 100644
--- a/litedram/frontend/axi.py
+++ b/litedram/frontend/axi.py
@@ -11,6 +11,7 @@ Features:
 
 Limitations:
 - Write response always supposed to be ready.
+- Last signals not used.
 - No reordering.
 """