Constraining Input or Output Logic - Constraining Input or Output Logic - 2026.1 English - UG903

Vivado Design Suite User Guide: Using Constraints (UG903)

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

Do not use set_max_delay or set_min_delay for input or output logic on a regular basis. Constrain logic between input ports and the first register stage with set_input_delay, which lets you associate a clock with the input ports.

For outputs, constrain logic between the last register stage and the output ports with set_output_delay. Use set_max_delay or set_min_delay for pure combinational in-to-out I/O paths between primary inputs and primary outputs.