Spectre netlisting alter model name

[Bernd Fischer]

Hi,

I'm wondering if there is a way to tell
the spectre netlister to use a alternative model
name rahter then the default one.

The objective is to use a second model for several
primitive devices in special simulations.

I could go through the design hierarchy with SKILL
and change the model name. But if there is a write
protected cell in the hierarchy I have to make a local
copy of all the cells down to the write protected one and
reorganize the references.
This is some effort for the designer and I'm afraid this
will end up in a mess of the design hierarchy.

So I'm looking for a way now to tell the netlisting
process to use alternative models.

Any ideas are welcome, thanks
Bernd

 

[uli]

Bernd Fischer wrote:

Hi,

I'm wondering if there is a way to tell
the spectre netlister to use a alternative model
name rahter then the default one.

The objective is to use a second model for several
primitive devices in special simulations.

I could go through the design hierarchy with SKILL
and change the model name. But if there is a write
protected cell in the hierarchy I have to make a local
copy of all the cells down to the write protected one and
reorganize the references.
This is some effort for the designer and I'm afraid this
will end up in a mess of the design hierarchy.

So I'm looking for a way now to tell the netlisting
process to use alternative models.

Any ideas are welcome, thanks
Bernd

You could create an additional view parallel to your
primitive's symbol, something like a "schematic", with
a viewname that is not in the switch-list.
Inside that schematic you place a symbol, which by
default uses your special model. Then you can use
hierarchy editor to decide which view (model) to use.
I did not test this, it is just an idea.
Unfortunately you need to go down one more stage in
hierarchy to inspect the backannotated parameters of
your device after simulation.

Uli

 

[Andrew Beckett]

On Fri, 20 Oct 2006 18:28:23 +0200, Bernd Fischer
<bernd.fischer@xignalerif.r'4054-50];p5.de> wrote:

Hi,

I'm wondering if there is a way to tell
the spectre netlister to use a alternative model
name rahter then the default one.

The objective is to use a second model for several
primitive devices in special simulations.

I could go through the design hierarchy with SKILL
and change the model name. But if there is a write
protected cell in the hierarchy I have to make a local
copy of all the cells down to the write protected one and
reorganize the references.
This is some effort for the designer and I'm afraid this
will end up in a mess of the design hierarchy.

So I'm looking for a way now to tell the netlisting
process to use alternative models.

Any ideas are welcome, thanks
Bernd

Hi Bernd,

You might be able to do this with view-specific CDF (this is a bit of a stab in
the dark, without having tested it).

If you have a second stopping view, you can add view specific CDF for a view
with that name - and change the model name in that view specific CDF.
From memory, this is covered by the SKILL function almSetModuleName - check
in the docs around this function.

Then you could use the hierarchy editor to switch views for the instances you
want.

If I have a moment today, I'll try this out.

If you want to do this for all transistors, then you're better off defining a
different model with the same name, and including that instead.

Regards,

Andrew.
--
Andrew Beckett
Principal European Technology Leader
Cadence Design Systems, UK.