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Design Languages >> Verilog-AMS >> Check Simulator Settings from within module
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Message started by Stefan on Jan 23^rd, 2008, 2:55pm

Title: Check Simulator Settings from within module
Post by Stefan on Jan 23^rd, 2008, 2:55pm

Hi,

does anyone know if it's possible to check the simulator options from within a module ?

In the special case, I need to know the settings of fmax of transient noise in AMS (spectre solver).

Kind regards,

Stefan

Title: Re: Check Simulator Settings from within module
Post by Geoffrey_Coram on Jan 28^th, 2008, 6:54am

Verilog-AMS LRM 2.2 added the $simparam() system function to get values from the simulator; GMIN, for example, is explicitly mentioned. FMAX is not, so you'd have to check with your simulator vendor and probably request an enhancement.

Title: Re: Check Simulator Settings from within module
Post by Marq Kole on Mar 19^th, 2008, 2:44pm

An approach that works in Spectre is to define a parameter with the fmax value and pass it to the model and to the relevant option of the transient analysis instance.

Cheers,
Marq

Title: Re: Check Simulator Settings from within module
Post by Geoffrey_Coram on Mar 20^th, 2008, 6:11am

Marq -
That approach might work OK if you are writing the netlist. But if you're developing a Verilog-A model for use in other people's simulations, and they use ADE to generate the netlist for Spectre (where ADE is responsible for taking the FMAX value from a box on the GUI form and putting it in the netlist), then I don't think your approach is viable.

-Geoffrey

Title: Re: Check Simulator Settings from within module
Post by jbdavid on Apr 13^th, 2008, 11:42pm

I was hoping that the $simparam would let me access ANY variable in the Model files used by the underlying spice simulator..
for the LAST project where I needed to get the values of modelfile parameters into the models, I created special subcircuits
in the model files with voltage sources set to the parameter value..
then instantiated those in my model.. and used the voltage connection read the parameter value.
-- in a large design where I might have many models needing this value it would be quite inefficient.
but it was something that I could do that day with things under my control.

-- now maybe the LRM couldn't tell me about these variables because it relates to a specific simulator function..
but I hopefully simulators will provide more such values..
--
Alternately, I might do something with a netlist pre-processor.. but that might limit the use of something in a corners tool situation.
jbd