Stats

  • Locked Locked
  • Replies 6
  • Subscribers 127
  • Views 15781
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

HSPICE to spectre warning

Saeed Gharagoz
Hi, After I have managed to convert FinFET model from HSPICE to Spectre, during simulation of a current mirror circuit I get this warning for 5 times: Parasitic resistor 'bias independent gate resistance' has been deleted because its value of 41.667mohm(R/MFactor) was smaller than 'MinR'. And I can see different voltages at different node but no currents into two FinFETs. Just to make everything more clear, this is what i've done so far. I have two files that contain the models, one for back gate one for front gate. They are included in the main file that supposed to model the FinFET. Thanks

  • Bit hard to tell whether this is really your issue, but sometimes for high current devices, you need to set the minr parameter in the model parameters. Be careful fo setting it too low though (it can lead to convergence difficulty). The default in most transistor models is 100mOhm. If this doesn't solve your problem, Customer Support is probably a good step, because then there's a chance of being able to look at your model (potentially) to see what the precise problem is.

    Regards,

    Andrew.

  • Thanks Andrew. I tried to contact customer service but it seems that I have to register and provide Host ID or Ref. Key. These are university computers and I am not sure if I'll be able to get them. Is there any other way to contact them? Thanks

  • Send an email to support@cadence.com - although at some point  you'll need to show you are entitled to get support. Depending on where you are, you may get support via a different route (e.g. Europractice in Europe). Look at the top of this web page, at the "Support & Training" link, which has an item "University Software Program".

    Regards,

    Andrew.

  •  Hi Saeed,

    There will be one Licensing Professor and two technical liasons at your University - they are the point of contact for all communication with Cadence Customer Support.  You will need to talk to your Professor to see who these people are and work through them.

     best regards,

    Tawna 

  • I am doing something similar to what is talked about in this thread, i.e. including a spice model in a spectre simulation.  How do I set the minr parameter that you speak of?  What is the syntax?  I can set it from ADE, but it has no effect and I continue to get the resistor has been deleted because is value is too small warning.  

     

    So after the line "simulator lang=spice", can I somehow add minr=1e-3 or something?  Attempting to set the parameter from the ADE menus does not seem to work.

  • minr can be either specified in the model definition itself (see "spectre -h bsim4" for example, or in the global options statement (see "spectre -h options". Whether you do this in spectre or spice syntax depends on whether your models are in spectre or spice syntax - although the options really should be in a spectre language block:

    myopts options minr=1e-4

    Note that you should be wary of setting minr too small, and also be aware that minr in the model will override the global minr specified in an options statement.

    Regards,

    Andrew.

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.