delay_var :
A variable transport delay for xreal-typed signals

The delay_var primitive models a variable transport delay for xreal-typed signals. In other words, it delays an xreal-typed input in to the output out by the time amount controlled by another xreal-typed input delay.

Note that the delay input must satisfy the following two conditions at all times. First, its value must be no less than a unit timestep (no future prediction). Second, its time-derivative must be less than 1.0 (no time-reversal).

For modeling a fixed transport delay for xreal-typed signals, use the delay primitive. For modeling a fixed or variable transport delay for xbit-typed signals, use the delay_xbit or delay_to_clk primitive, respectively.

Input/Output Terminals

Name	I/O	Type	Description
out	output	xreal	output signal
in	input	xreal	input signal
delay	input	xreal	delay