What are the scenarios that are covered by set_case_analysis?
set_case_analysis can be used with BUFGMUX,LUT, F8MUX, the Reset pin of the FF, and the Enable pin of the FF.
However, the most common use of this command will be with the BUFGMUX.
In all situations, the command should influence the timing arcs used by the timing engine for timing analysis.
The individual delays through these component will be different, which impacts the clock skew analysis.
You will see a warning with the LUT in the clock path like the following:
WARNING: [Timing 38-153] LUT was found on the path where set_case_analysis is applied
However the BUFGMUX and F8MUX work as expected.
The F8MUX should only be used for clocking when all the BUFGMUX components are utilized.