update doc about the limitation on using tileable routing
@@ -54,7 +54,7 @@ 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!!!
+ .. warning:: You cannot use ``spread`` 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:
