set_property USER_CLOCK_ROOT X3Y2 [get_nets -of [get_pins clkgen/BUFG_clkout2_inst/O]]
After placement, you can use the CLOCK_ROOT property to query the actual clock root as shown in the following example. The CLOCK_ROOT reports the assigned root whether it was user assigned or automatically assigned by the Vivado tools.
get_property CLOCK_ROOT [get_nets -of [get_pins clkgen/BUFG_clkout2_inst/O]] => X3Y2
Another way to review the clock root assignments of your implemented
design is to use the
command. For example:
The following figure shows this report.