When I create the VIO core, the NCF is not created properly.
When I create a VIO core using CORE Generator, the "vio.ncf" is generated, but is left blank; this causes timing violations in a design related to the VIO.
The problem is that the following constraint is missing:
# Clock constraints
NET "CLK" TNM_NET = D_CLK ;
To work around these issues, manually add the constraint.
This issue is resolved in ChipScope Pro 11.1.