When I checked about the reason why we see "No Constrained paths" or "No Paths" in PrimeTime when we do report_timing -from <start_point> -to <end_point> , I got to know that there might be few reasons which are given below.
There is no topological combinational path between these two pins.
A topological combinational path exists, but is blocked by one or more disabled timing arcs
Can anyone please explain clearly what is a topological combinational paths ?
just meaning there is not combinational path between the two pins you ask for a report timing.
you could ask the Primetime to report timing also for non-constraint path to have at least the delay cells/nets between these two pins.