Exporting the Merged Exceptions - 2025.2 English - UG906

Vivado Design Suite User Guide: Design Analysis and Closure Techniques (UG906)

Document ID
UG906
Release Date
2025-12-10
Version
2025.2 English

Use the report_exceptions -write_merged_exceptions command to export the list of timing exceptions as processed by the static timing analysis (STA) engine.

The Vivado timing engine merges similar or overlapping timing exceptions internally to reduce memory usage and improve runtime. This merged view reflects how the STA engine actually interprets and applies your constraints.

Note: Timing constraints set_clock_group and set_bus_skew are not exported.
Note: Invalid startpoints and endpoints are not filtered out when the merged timing exceptions are exported.

The following figure shows the results of running report_exceptions -write_merged_exceptions on the two set_false_path constraints described in the Reporting the Ignored Objects section. In this example, the second set_false_path constraint includes all pins of the register because the -from and -to options use the pattern int21_reg/* with the get_pins command. The merged report reflects how the Vivado timing engine combines these constraints for analysis.

Figure 1. Merged Exceptions