I have a design with two partitions on lower-level instances (rnd1, rnd2) which are unrelated to any other logic. I add some logic with a new clock and other signals which are also irrelevant to the two modules, and put a period constraint on this clock. When I save the constraint, these modules are marked out of date, and changed to orange status.
The NGDBuild report indicates the following:
Partition Implementation Status
-------------------------------
Preserved Partitions:
Implemented Partitions:
Partition "/Top":
Logic within this Partition was modified by a Period change.
Partition "/Top/rnd1":
Logic within this Partition was modified by inheriting a Period change.
Partition "/Top/rnd2":
Logic within this Partition was modified by inheriting a Period change.
This is correct behavior. A timing constraint change affecting the top partition will make all partitions as out of date. To override this behavior, set the following environment variable as 1:
XIL_NTRC_NO_TIMING_CHILDREN
setenv XIL_NTRC_NO_TIMING_CHILDREN 1