update docoumentation about the constraints when using tileable rr_graph generator
@@ -54,6 +54,8 @@ Layout
.. warning:: Currently ``through_channel`` supports only a fixed routing channel width!
+ .. warning:: You must define custom pin location for the ``height > 1`` or ``width >1`` tiles when using the tileable routing resource graph!!! Otherwise, it will cause undriven pins in your device!!!
+
A quick example to show tileable routing is enabled and through channels are disabled:
