The Timing Constraints wizard
does not recognize some valid CDC topologies that do not use simple synchronizers. The
report_cdc command offers a powerful and more
comprehensive view of CDC paths that need structural correction to become safe. For
detailed information about report_cdc, refer to the
Vivado
Design Suite User Guide: Design Analysis and Closure
Techniques (UG906)
When the wizard does not recommend a constraint because a set_max_delay -datapath_only exists, review the remaining
CDC paths that are normally timed. Use additional false path constraints to ignore these
paths if needed. Create point-to-point false path constraints in the XDC file, in the
Tcl Console, or in the Timing Constraints window after exiting the wizard.