The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Mar 29th, 2024, 1:01am
Pages: 1
Send Topic Print
Parasitic extraction with Assura (Read 2000 times)
asdf
Junior Member
**
Offline



Posts: 12
Armenia
Parasitic extraction with Assura
Oct 28th, 2005, 3:53am
 
I use Assura RCX and need to get extraction output in Spectre fornat but generated output file contains some statements that are not in Spectre syntax.
e.g.
1. it contains .SUBCKT and .ENDS statements
2. the unit prefixes (microns) are in higher case U but it need to be in lower case
3. when in resalt are included parasitic resistance models as a coment the comment begines with $ sign which is not in spectre sintax

I cannt find where must be made the changes to get correct resalts, please help!
Back to top
 
 

Bergerak
View Profile marimna   IP Logged
Paul
Community Fellow
*****
Offline



Posts: 351
Switzerland
Re: Parasitic extraction with Assura
Reply #1 - Oct 28th, 2005, 5:24am
 
I'm not sure you can do this inside Assura. Maybe you can request a SPICE netlist instead of Spectre format (see the user's guide on that), so you will at least get the .subckt and .ends statements. For the rest, I suggest you write a script (e.g. in Perl).

Paul
Back to top
 
 
View Profile WWW   IP Logged
bernd
Senior Member
****
Offline



Posts: 229
Munich/Germany
Re: Parasitic extraction with Assura
Reply #2 - Oct 28th, 2005, 6:30am
 
AssuraRCX can output various formats depending of the version
you are using.
?outputFormat { “spice” | { “dfII” | “dfii” } | “dspf” }
In general I use Assura out of DFII which then is the best bet to use
dfII as the output format and generate an so called extracted view which
easily can be plugged in to your simulation testbench with the hierarchy editor.

I assume you use Assura in batch mode?
If you select Spectre as an output format Assura first generates a Spice netlist
then it starts a  postprocessing to generate the Spectrec netlist out of the Spice one.
Which I think is a bit poor implemented, so no direct Spectre netlister here.
I don't know, but might be that this could cause your problem.

See the Assura Command Reference & and User Guide
documentations and have a look for this tow commands
?outputFormat { “spice” | { “dfII” | “dfii” } | “dspf” }
Which defines the out put format.
?pipeAdvgen    "spp -convert -log  <cellName>.scs.log"
Which redirects the Spice netlist to a Spectre one, 'spp'
is the Cadence  Spice reader which  is also be used by Spectre
to convert real Spice models for simulation purpose.

Bernd

Back to top
 
 

Just another lonesome cad guy
View Profile WWW   IP Logged
Paul
Community Fellow
*****
Offline



Posts: 351
Switzerland
Re: Parasitic extraction with Assura
Reply #3 - Oct 28th, 2005, 2:40pm
 
After reading Bernd's answer, I noticed that I completely misunderstood your initial post... Thought you wanted to get the features you list, not the opposite. My apologies, fortunately week-end's close.

Paul
Back to top
 
 
View Profile WWW   IP Logged
asdf
Junior Member
**
Offline



Posts: 12
Armenia
Re: Parasitic extraction with Assura
Reply #4 - Oct 31st, 2005, 12:24am
 
Thank You for comments!
I use Assura in grafical mode but the results are the same as in batch mode: I get Spice netlist whan Spectre is selected as the output format.
In my RSF are included the following two commands:

?outputFormat      "spice"
?pipeAdvgen    "spp -convert -log  <cellName>.scs.log"

anyway I get <cellName>.scs file which is Spice format.
I think the convertion is not performed but I cannot understand why.
I also tried to run "spp -convert -log  <cellName>.scs.log" command from command line, but I don't get result.

The convertion can be performed bay command
"spp -convert -iofile <inputfile> <outputfile>"
but this command does not work whan included to RSF as a pipe command.
Back to top
 
 

Bergerak
View Profile marimna   IP Logged
bernd
Senior Member
****
Offline



Posts: 229
Munich/Germany
Re: Parasitic extraction with Assura
Reply #5 - Nov 1st, 2005, 10:19am
 
If you run Assura in GUI mode out of DFII, may
I asked the question why you try to get a Spectre
netlist rather than use the extracted view?

If you realy neccessarly need a Specte netlist, as
a workaround you can also create an extraced view with Assura, then open it and call the Analog Environment (Artist) out of it and create a Spectre
netlist out of Artist.

Bernd
Back to top
 
 

Just another lonesome cad guy
View Profile WWW   IP Logged
asdf
Junior Member
**
Offline



Posts: 12
Armenia
Re: Parasitic extraction with Assura
Reply #6 - Nov 1st, 2005, 11:24pm
 
Thank you Bernd
The extracted view is a  solution and another way also exists, but these methods
require additional operations.
so I need to use shorest way to get netlist for  saving the time.
Back to top
 
 

Bergerak
View Profile marimna   IP Logged
Andrew Beckett
Senior Fellow
******
Offline

Life, don't talk to
me about Life...

Posts: 1742
Bracknell, UK
Re: Parasitic extraction with Assura
Reply #7 - Nov 4th, 2005, 5:15am
 
What do you mean these require additional operations? It will be much less work to use an extracted view. Otherwise you need to ensure that you've set up the termOrder in the CDF for the block you're going to simulate with the same order as it appeared in the extracted SPICE or spectre netlist - and that order may vary. It sounds painful to me to use that approach when the extracted view approach is well integrated.

Andrew.
Back to top
 
 
View Profile WWW   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2024 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.