Simulation with varilog-a model and cadence included models.

I made some IV benchmarks in skill/ocean.I run them with some bsim
technologies that I have (0.25,0.90..) but I need more models.

Where can I find the models(ekv …) that come with cadence.(a path to
there library or something… )?

I also have the veriloga code of ekv3.1 (from an ADS desing kit). I
try using verilog in from verinuser.pdf but didn’t work. I have no
experience with veriloga or how to used it.
Can some one help me how to run my circits using the verilog a model.
In my ciruits I use nmos4-pmos4 from analoglib to pass data to the
models and I use spectre for the simulation.

Thank you for your help.

 

Hi prodromos,

I am not sure I have understood your question ...
Spectre does support EKV models and you don't need to dive into how
they are implemented in the software itself.
All what you need is to ask your foundry to provide you with the EKV-
based model cards for Spectre, simple as that.

When you have run the IV benchmark with BSIM3/BSIM4, I guess you have
the models cards from your foundry do you ? Well, you need the same
thing for the EKV.
If your foundry provides same model names for the transistors, then
you can switch back and forth between BSIM/EKV using the Spectre
Include Dir.

Yes, the EKV are written in Verilog-A for Spectre but you don't need
to load anything at all, it's all there for you.

Hope this helps,
Regards,
Riad.

 

hello Riad.
thank you for the replay.

if i understand correctly
my foundry dont have any models cards for ekv in spectre.only for
ADS.
the bsim models i use are part of a techology (not sure if this is the
term.)
i provide a path to the model like
modelFile( '("/opt/Cadence/sgb25vd/tech/spectre/models.typ")....
and a model name like nmos.

i use analog lib nmos4 so i am able to use any model.Is there a chance
that they will not work (if they are made for spectre)?

is there any thing i can do without the model cards?
my professor in one of the people that develops ekv but he didnt
mention any thing about if there is a spectre version besides ekv2.6
in cadence.
thats why i ask where to find ekv2.6 in cadence (modelFile path for
it.) there are many model folders but i dont know which one to use...
but he will like me to use a newer version if possible.

 

Hi Prodomos,

When you place your analogLib nmos4, you must give it a model name.
This model name should be defined in a model card that your foundry
provides as explained before.

Spectre does support ekv 2.6. Please do the following:
1. From your Cadence Library manager, go to File -> Open Shell Window.
Type the following into the xterm that just poped out:
spectre -h ekv
I got the following in my case.
113 update=2.6 Model version selector.

Again, What you need to worry about is whether you have an ekv model
card or not. The way ekv is implemented in Spectre if of no use for
you as long as the right version of it is well supported.
Talk to your Professor and he will be able to get you some more
information about it.
If you don't have any ekv model cards then you may visit the EPFL-EKV
web site where you could download some generic ones (not 100% sure
though, give it a try).

Cheers,
Riad.