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Design Languages >> Verilog-AMS >> Two questions about verilog-A
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Message started by icsoul on Jun 13^th, 2008, 2:16am

Title: Two questions about verilog-A
Post by icsoul on Jun 13^th, 2008, 2:16am

1. I want to measure the input clock period and give it output as a signal. But it seems that the verilog-A cannot deal with non-electrical port, isn't it? Then how can I solve this problem?

2. I want to measure the max, min, mean value in real time and give them output as signals. How to implement this?

Thanks!~

Title: Re: Two questions about verilog-A
Post by Stefan on Jun 13^th, 2008, 3:29am

1.)
In "real world" clock signals are not digital :)
So you could use analog clock signals for that. However, if you don't use a mixed-signal simulator, you won't be able to handle digital signals annyway. And if you're using a mixed-signal-simulator, you should consider using verilog-AMS instead of verilogA which would enable you to use digital ports.

2.) max/min/mean of the period ? You could either use an analog port to drop the value as voltage, or you can use the ncsim display to display values from the inside of the modelling blocks variables.

Title: Re: Two questions about verilog-A
Post by Ken Kundert on Jun 13^th, 2008, 1:49pm

Yes, Verilog-A can handle non-electrical signals. To do so you will need to create the appropriate natures and disciplines. I believe I show how to do this in my paper on modeling noise and jitter in a pll. I do it in the section on phase domain models, where I create natures and disciplines for phase.

-Ken

Title: Re: Two questions about verilog-A
Post by icsoul on Jun 15^th, 2008, 9:18pm

Stefan wrote on Jun 13^th, 2008, 3:29am:

I use HSPICE as the simulation tool. So I can only use verilog-A.

I want to know how to calculate the max/min/mean of any input continuous signal, not only period.

Thanks!

Title: Re: Two questions about verilog-A
Post by icsoul on Jun 15^th, 2008, 9:28pm

Ken Kundert wrote on Jun 13^th, 2008, 1:49pm:

Hi, Ken

Do you mean the following part?
`include “disciplines.vams”
discipline phase
potential Angle;
enddiscipline

It seems that if I add a discipline for time(period), the nature would be added first, isn't it?

Could you give some hints for calculating the max/min/mean values of input continuous signal?

Thanks!