Many clocks can exist in a design; however, not all clocks interact with one another, and certain clock interactions are not possible. Asynchronous clocks are unrelated clocks (asynchronous clocks have different ideal clock sources). Exclusive clocks are not active at the same time (e.g, multiplexed clocks). The mutual exclusivity must be declared to the Timing Analyzer to prevent it from analyzing these clock interactions.
You can use the set_clock_groups command to specify clocks that are exclusive or asynchronous. The following list shows the set_clock_groups command, including the available options: