update the arch reference to say that SG is only supported in 3D with unidir links

soheilshahrouz · soheilshahrouz · commit a5517e1f6f91 · 2025-09-26T16:19:04.000-04:00
diff --git a/doc/src/arch/reference.rst b/doc/src/arch/reference.rst
@@ -2670,7 +2670,7 @@ The number of any additional wires or muxes created by scatter-gather specificat
     Overview of how scatter-gather patterns work. First, connections from a switchblock location are selected according to the specification.
     These selected connection are then muxed and passed through the scatter-gather node, which is typically a wire segment. The scatter-gather node then fans out or scatters in another switchblock location.
 
-.. note:: Scatter-Gather patterns are work in progress and experimental. Currently, VPR does not support this specification and using this tag would not result in any modifications to the RR-Graph.
+.. note:: Scatter-Gather patterns are only supported for 3D architectures where the scatter-gather links are unidirectional. They are not currently supported in 2D architectures or with bidirectional sg_links.
 
 When instantiated, a scatter-gather pattern gathers connections from a switchblock and passes the connection through a multiplexer and the scatter-gather node which is typically a wire segment, then scatters or fans out somewhere else in the device. These patterns can be used to define 3D switchblocks. An example is shown below:
 
