An individual or project-wide timing assignment that specifies the delay of a signal from an output pin before it is registered externally (outside the device). The value of this assignment usually represents the t_SU of an external register fed by the data output pin of the device, plus the actual board delay. If you make this assignment to an individual node, you must assign it to an output or bidirectional node.

To include external delays in timing analysis calculations, you must turn on Include external delays to and from device pins in fmax calculations in the Clocks page of the Settings dialog box (Assignments menu).