Output Delay - Output Delay - 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 set_output_delay to specify the output path delay of an output port relative to a clock edge at the design interface.

Video: For training on output delay, refer to Vivado Design Suite QuickTake Video: Setting Output Delay.

When you consider the application board, this delay represents the phase difference between the following:

  • Data propagating from the FPGA output package pin, through the board, to another device.
  • The relative reference board clock.

The output delay can be positive or negative, depending on the clock and data phase outside the FPGA.

Note: You can also set output delays on internal data pins such as STARTUPE3/DATA_OUT[0:3] (UltraScale+ devices).