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Simulators >> Circuit Simulators >> Model parameter sweep in Spectre
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Message started by shchangtx on Jan 17^th, 2006, 3:23pm

Title: Model parameter sweep in Spectre
Post by shchangtx on Jan 17^th, 2006, 3:23pm

Hi,

I am trying to get ID-TOX (gate oxide thickness) plot with VD=VG=3V for various TOX.
In Cadence Analog Environment > Analyses > Choose > dc analysis / Model Parameter in Sweep Variable, I typed tsmc25N for Model Name field and TOX for Parameter Name field.
tsmc25N is the model name in properties window of the tr and TOX is gate oxide thickness in tsmc25 model parameter.

When I run the simulation, it gives error.
[ Error found by spectre during hierarchy flatterning
dc: Invalid model name was "tsmc25N" given as value of parameter 'mod'.
name conflict: value 'tsmc25N' of type 'scalar string' encountered.
Expected value is of type 'scalar model'.
spectre terminated prematurely due to fatal error ]

Below is front part of the model parameter. the file name is model25.spi.

* T14Y SPICE BSIM3 VERSION 3.1 PARAMETERS

* SPICE 3f5 Level 8, Star-HSPICE Level 49, UTMOST Level 8

* DATE: May 23/01
* LOT: T14Y WAF: 03
* Temperature_parameters=Default
.MODEL tsmc25N NMOS ( LEVEL = 11
+VERSION = 3.1 TNOM = 27 TOX = 5.7E-9
+XJ = 1E-7 NCH = 2.3549E17 VTH0 = 0.3865307
...

I searched for cadence references but it is just like MS help. :'(

Any reply will be appreciated!

Thanks

Title: Re: Model parameter sweep in Spectre
Post by Andrew Beckett on Jan 17^th, 2006, 9:17pm

First of all, TSMC normally provide native spectre models - which would be preferred to using SPICE syntax models. But that said, this should not be insurmountable (especially if you're using the new front end in spectre - e.g. using MMSIM60, or using the +csfe option in IC5141).

Because your models are in SPICE syntax, they are case insensitive. The rest of the spectre netlist will be case sensitive. What this means is that the model name would be folded to lower case, so you should specify the model name as "tsmc25n", rather than "tsmc25N". The parameter name should be "tox".

Regards,

Andrew.

Title: Re: Model parameter sweep in Spectre
Post by shchangtx on Jan 18^th, 2006, 7:17am

Thanks a lot!
It worked. :)

Regards,

Sanghoan