How can I import the model card to the Cadence?

I'm a bit confused as to why I need to keep explaining the same thing over and over again. Anyway, the flow is:

1. Put the model in a text file (e.g. nmos.spi) somewhere
2. Place an instance of nmos4 from analogLib, and specify the model name as "NMOS" (since that's what it is in the file), and specify the width and length on the instance of nmos4. w and l are instance parameters not model parameters - the idea is that the same model is used for a variety of widths and lengths (as is common with pretty much all MOS models)
3. In ADE use Setup->Model Libraries and add the path to the file (nmos.spi) that you created in step 1.

I have mentioned in other threads (that I referenced in your earlier questions) that you could create your own copy of nmos4 in your own library and use Tools->CDF->Edit to update the model name to be filled in by default - this is normally what you'd do if creating a PDK component. Probably not worth the bother for simple experimentation.

Andrew.

Thank you for your accurate reply

yysunj

I put my model into a text file as you said.

And, nmos4 from analogLib is placed in the virtuoso, the model name is NMOS, and the width and length were specified.

And, I added the path of the file I created by using Setup -> Model in ADE.

But, when I try to use this model, I get a warning.

How can I solve this problem?

Please tell me.

Dear yysunj,

yysunj said:

How can I solve this problem?

Please tell me.

As Andrew noted, there are many, many posts as well as some very good instructions for this process on the Cadence On-line support site. A search on the Cadence On-line support site will provide the following Application note that I have used countless number of times to create a model from a text file for a spectre simulation. Have you seen this article? I think it will help with your issue.

FAQ: How to Include a Subcircuit (Netlist) into a Schematic and Simulate in ADE

Shawn

I don't really see what the last screen shot has to do with anything else. You're trying to instantiate a cell called "LLL" with a symbol that doesn't exist. Nothing you were doing in the earlier steps had anything to do with creating "LLL" as far as I can tell. To use the model, you instantiate analogLib/nmos4 as you did in the first step.

Or (as a wild guess) you placed the instance of the nmos4 into a schematic called LLL and now you want to instantiate that? If so, you'd need to create a symbol for that schematic - but surely that's rather obvious, so it can't possibly be that.

Shawn did (above) give some other suggestions for handling this kind of import, although those are more appropriate for dealing with subckts of SPICE blocks rather than models, but you can certainly learn a lot from the approaches taken in that FAQ.

Regards,

Andrew

The "LLL" of the last screen is the cell name of the cell in the second screen. I did all step which you said, but I can not import my spice model to cadence spectre, yet.

I want to know what I have done wrong.

And, I want to know how can I create a symbol for that schematic (scematic of second screen).

Please tell me.

yysunj

For a start, I don't think you need to create a symbol for this - just place the nmos4 symbols, with the right model and width and length, in your design schematic - and then simulate just as you've simulated anything else. 

If you want to create this as some kind of wrapper component - i.e. with a schematic which just contains the single transistor, then you'd create symbols just as you create symbols for any other level of hierarchy - do I really have to explain the basics of Virtuoso? In other words, you'd add D, G, S, B pins, wire them to the pins on the instance of the analogLib/nmos4, and then either do Create->CellView->From CellView to create a symbol (a rather boring box) or better still just copy the analogLib/nmos4/symbol to yourLib/LLL/symbol and re-use the same symbol. I don't really understand why you need to create an additional symbol here - it's far simpler to just instantiate the transistor directly - after all, you're going to want to change the width and length for different transistors anyway (it's rather unlikely you'd want all transistors to have the same size).

If this doesn't make sense, please speak to a supervisor (I assume you must be at a university) to get some assistance on basic design tool usage.

Kind Regards,

Andrew

Thank you for your prompt reply!

yysunj