raja.cedt wrote on Jun 21^st, 2009, 9:16am:
I can't understand what you are confusing.

Use pulse() like following.
Quote:

raja.cedt wrote on Jun 22^nd, 2009, 1:46am:
Create signal sources using Verilog-A.
It is very easy to generate such signals if you use $abstime, @timer() and transition() in Verilog-A.

If frequency variation is continuous, you can use FM-signal source and limitter to generate pulse signal of continuous FM without using Verilog-A model.

As another method, you can use signals based on VCD(Value Change Dump) format data.
This method is also implemented in both Cadence Spectre and Agilent GoldenGate.

http://www.designers-guide.org/Forum/YaBB.pl?num=1207062028/4#4

Currently almost all commercial transient simulator have an ability of generating signal based on VCD(Value Change Dump) format data.