Clock Fall Input Delay Command Option - Clock Fall Input Delay Command Option - 2026.1 English - UG903

Vivado Design Suite User Guide: Using Constraints (UG903)

Document ID
UG903
Release Date
2026-07-01
Version
2026.1 English

Use -clock_fall to apply the input delay to paths launched by the relative clock’s falling edge. Without this option, Vivado IDE uses only the rising edge.

Do not confuse -clock_fall with -rise or -fall; those refer to the data edge.