Slide 39 of 93
The keyword TRANSPORT must be used to specify a transport delay.
Transport delay is the simplest in that when it is specified, any change in an input signal value may result in a new value being assigned to the output signal after the specified propagation delay.
Note that no restrictions are specified on input pulse widths. In this example, Output will be an inverted copy of Input delayed by the 10ns propagation delay regardless of the pulse widths seen on Input .