delay_to_clk :
A delay-to-clock domain translator.

The delay_to_clk primitive delays an input xbit-typed signal trig (usually a clock) to an output xbit-typed signal out by the delay amount expressed by an xreal-typed input in.

The delay expressed by in must be greater than a unit simulation time step. If the delay changes while the input edge is still propagating to the output, the time-average of the input delay during the transition period will determine the overall delay.

The delay_to_clk primitive can also add random jitter or phase noise to the output signal. The added random jitter can contain independent jitter as well as accumulated jitter, each of which is specified by the parameter RJ_rms and RJ_kappa, respectively. The parameter RJ_rms defines the RMS value of the independent random jitter, which has fixed statistics regardless of the delay. On the other hand, the parameter RJ_kappa defines the RMS value of the accumulated random jitter, which increases as a square-root function of the delay. The total RMS value of the random jitter added to the output signal can be expressed as:

        Total RMS value of random jitter (RJ) = sqrt(RJ_rms^2 + RJ_kappa^2 * delay).

Alternatively, the added phase noise of the output clock can be specified using the phase noise parameters PN_fcenter, PN_foffset, PN_dbc, PN_fcorner, and PN_floor. Defining these phase noise parameters is equivalent to defining the random jitter parameters satisfying the following relationships:

        RJ_rms = 10^(PN_floor/20) / (2π*sqrt(PN_fcenter)),
        RJ_kappa = 10^(PN_dbc/20) * PN_foffset / PN_fcenter.

Note that the random jitter parameters RJ_rms and RJ_kappa cannot describe the 1/f noise (e.g. flicker noise) being accumulated over the delay, while the phase noise parameters can (PN_fcorner). For more information on these phase noise parameters, please refer to the documentation on the clk_gen primitive. These parameters typically describe the phase noise of an oscillator producing a clock at a certain frequency.

Input/Output Terminals

Name	I/O	Type	Description
out	output	xbit	clock output
trig	input	xbit	trigger input
in	input	xreal	delay input

Parameters

Name	Type	Default	Unit	Description
RJ_kappa	real	0.0	second	RMS accumulated random jitter after 1 second
RJ_rms	real	0.0	second	RMS independent random jitter
PN_fcenter	real	-1.0	Hz	phase noise center frequency
PN_foffset	real	0.0	Hz	phase noise offset frequency
PN_dbc	real	-`INFINITY	dBc/Hz	phase noise measured in dBc/Hz
PN_fcorner	real	0.0	Hz	1/f^3 phase noise corner frequency
PN_floor	real	-`INFINITY	dBc/Hz	phase noise floor measured in dBc/Hz