Users who have used releases of the DS344 prior to version 5.0, or those converting v7 designs to v8, may notice that in XACT 5.x, properties placed on I/O pads do not appear in the resulting XNF netlist. The most common indication of this problem is that LOC properties on I/O are ignored, causing unexpected pin placement.
In the XACT 5.0 release, the CLASS=P property was added to the I/O pad symbols to improve compatiblity with other Mentor tools (most notably, to improve board-level simulation). One unfortunate side effect of this is that properties placed on the I/O are now ignored.
See page 4-6 of the XACT 5.0 Mentor Interface User's Guide for more information.
The workaround is to place the properties on the net or buffer associated with the PAD.
See page 4-6 of the Mentor Graphics Interface/Tutorial Guide (previously known as the Mentor Version 8 Interface User Guide) for more information.