av_extracted & selecting nets for Spectre simulation

Hi All,

I'm using Assura QRC to generate an av_extracted view & then Spectre
to
simulate this view.

As we have a large number of nodes I'd like to select specific nets on
which to save simulation data. However my extracted view is of RC type
so each schematic net gets broken to accommodate the parasitic
resistance of the tracks.

So for example, if i were using a spice netlist a schematic net called
"net10" might become net10#1...net10#2...etc. So i'd guess that the
av_extracted view does something along these lines?

Is there a simple way in which to tell Spectre to save data for all
nets
associated with "net10", could i use a wildcard:

*net10*

to tell Spectre to save data for all nets containing this string?

Thanks

Stu

 

Hi Stu,

Yes, Spectre does support wildcards (assuming recent version of
MMSIM).
so if your Spectre Netlist contains:
save *net10*
then after simulation, you will find the following in the log file:
Wildcard matching statistics:
*net10* nodes: X
Where X in the above is the number of matches.

I usually don't miss about this and rather using the Hierarchy Editor
alogn with the ADE GUI to save my nodes from the av_extracted view.
This avoids any syntax headaches with hierarchy names and subnets.

Cheers,
Riad.

 

Riad KACED wrote, on 10/27/09 08:11:

Indeed. The way to do this is to create a file (say "savestuff.scs") containing
this spectre save command (type "spectre -h save" at the UNIX prompt for syntax
details) and then reference this file in ADE using Setup->Model Libraries.

Regards,

Andrew.

 

Hi Guys, we have this working now so thanks for the input. I had saved
"all" nodes but it seems to work when i changed to save "selected",
and now i only see the nodes of interest(i.e those in "my.scs") in the
results browser.

Thanks

Stu

 

stuso wrote, on 10/28/09 10:38:

Yes, "selected" in spectre's terminology means those things saved with a
specific "save" statement... (it's actually the default in spectre itself). If
there are no save statements though, it saves _all_ node voltages (because it
assumes you probably wanted to see something rather than nothing).

Regards,

Andrew.

 

Hello,

I think you can put pins on the nets you are interested, then just
select the pins for saving in ADE or write scripts in netlist:
saveOptions options save=selected
save pin1 pin2 ...

I think these are convenient in simulation.

 

Hi, the issue with this for me is for sub-blocks down the hierarchy,
we'd have to add functionally defunct pins to every net that we wish
to probe (though some of the guys do exactly this).

Thanks

Stu

 

stuso wrote, on 11/04/09 11:50:

I don't understand why you'd need to put pins on the nets you're interested in.
You should be able to save the nets in the extracted view directly by clicking
on the points in the layout.

If you want to save the entire net (as you described before), you need to use
the wildcard approach via an include file ( there's no GUI yet to specify
wildcarded nets ).

Regards,

Andrew.