Description

I have a project which contains IP cores and the processes run as expected, however, when I close the project and open it again, it goes stale. 

The process status is marked Out-of-Date with the explanation "IPs Modified."

Solution

In projects containing IPs, the "IP Modified" event was being fired incorrectly when a project was opened. 

The "IP Modified" flag forces the Synthesis status and any subsequent runs are marked as out-of-date.

To work around this, use the "Force up-to-date" function:

1. In the Vivado tool, click the More Info button (next to the Status indicator in the top right corner).
2. Select Force up-to-date in the information box.
   Alternately, individual processes can be forced up-to-date by setting the needs_refresh property to false in Tcl.

set_property needs_refresh false [get_runs synth_1]
set_property needs_refresh false [get_runs impl_1]

This issue has been fixed in the Vivado 2012.3 release.