Review the Check Timing section of the Timing Summary report to quickly assess the timing constraints coverage, including the following:
- All active clock pins are reached by a clock definition.
- All active path endpoints have requirement with respect to a defined clock (setup/hold/recovery/removal).
- All active input ports have an input delay constraint.
- All active output ports have an output delay constraint.
- Timing exceptions are correctly specified. CAUTION:Excessive use of wildcards in constraints can cause the actual constraints to be different from what you intended. Use the
report_exceptions
command to identify timing exception conflicts and to review the netlist objects, timing clocks, and timing paths covered by each exception.
In addition to check_timing
, the
Methodology report (TIMING and XDC checks) flags timing constraints that can lead to
inaccurate timing analysis and possible hardware malfunction. You must carefully review
and address all reported issues.
Note: When baselining the design, you must
use all Xilinx IP constraints. Do not specify user
I/O constraints, and ignore the violations generated by
check_timing
and report_methodology
due
to missing user I/O constraints. For more information on baselining the design, see
Baselining the Design.