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Things You Didn't Know About Virtuoso: It's Video Time!

Comments(4)Filed under: Custom IC Design, Virtuoso, IC 6.1.4, Virtuoso Analog Design Environment, IC 6.1, ADE-XL

Just a quick post to let you know that there have recently been a whole truckload of videos added to the Cadence Online Support Video Library.  (Some shameless self-promotion here--I created many of them...).  Simply go to http://support.cadence.com (registration required) and choose Resources->Video Library.  You may want to set up your product preferences to only view those product areas you're interested in.  And be sure to sign up for email notifications for your favorite products so you can get all the latest solutions and updates sent to you right away.

Many thanks to our Tech Pubs and CS folks for getting these posted for all to see.

There are videos on how to use many of the features in ADE XL (Analog Design Environment), VSE L and XL (Virtuoso Schematic Editor).   Here is just a sampling.  There are many more.  Also check out Samir's excellent new video on how to get started using OCEAN.

Bookmarks, tabs, recently-opened files list, Go toolbar, double-click hierarchy navigation, Library Manager customization, thumbnails

Specification types, Run toolbar, viewing specs in Results panel, output formatting (digits, units, notation--IC 614), using the Evaluate button

Creating temp. & voltage corners, creating and using model groups, running corners & sweeps, working with simulation history results, viewing corners results, plotting waveforms from individual corners

Comparing 2 corners runs after a change in the circuit, comparing results from 2 swept parameter values across corners

Add a value to a parameter sweep without rerunning original values, rerun only failed corners

Monte Carlo options, specify DUT, Yield view, histograms, scatter plots, Detail view, print stat. params., create stat. corner

So grab some popcorn, put your feet up, relax and enjoy the show!






By MarkSummers on April 13, 2010
Good Info.  I have couple questions that may have been covered but that I missed.

1) Corner Groups.  It is possible to create corner groups to make a single corner act like multiple corners.  It is possible to expand and concatenate these corner groups.  However is it possible to expand and concatenate results when a corner group is used.  When expanded all data would be shown.  I would assume in condensed form the pass/fail report would be for the sum of the corners.

2) DC operating points.  I think circuit checks can be used across corner/montecarlo simulations.  Will the circuit check highlight any devices in schematic that are linear for instance at any corner.  Then would it be possible to get a report on a device (selected) dcOpts across all corners or for specific corners.  I think this would be a powerful debug tool.  Measurements tell that something fails, but not always why.  Often times this is due to DC bias conditions.  So if it is possible to get quick visual notifications of bias failures(circuit check) as well as detailed reports, debug would likely be quicker.  

Sorry for the long post.  


By Stacy Whiteman on April 15, 2010
Thanks for the comments!
1) Corner Groups
Corner groups are really just ways to create a set of corners that can be enabled/disabled (on a test-by-test basisi, if desired) or modifed all at once.  They really don't provide any additional functionality with respect to results, although that is quite an interesting idea.  
FYI, the new Detail-Transpose view in the Results panel in IC614 let's you sort and arrange results based on corner names, temperature, variable values, etc.  This may do some of what you're interested in.  There is a video on this called "ADE XL: Results Panel Views"  (I can't seem to paste the link here, so you can do a search).
2) DC operating points
Yes, the circuit checks (or Device Checks, as they are called in the GUI) can check a variety of circuit conditions across corners, sweeps, etc.  RMB on any corner column in the Results will let you see and highlight device check violations for that specific corner.  You can also annotate voltages and operating point parameters for each corner.  The ViVA Results Browser (ADE XL->Tools->Results Browser) can be used to generate a table of operating point voltages and/or parameters across corners.  
I'll admit I haven't had time to explore this as thoroughly as I would like, so there are likely quite a few things which could be enhanced and/or explained better--something for a future project for me, I'm sure.
Thanks again,

By MarkSummers on June 8, 2010
A couple more questions.  Is it possible now or in near future to do the following
A) Failure Analysis
Set up actions to be taken when a corner fails.  This could any number of things.  Here are some rough examples
1 Rerun saving more nodes
2 Run longer simulation
3) Run sweeps(ie temp parameters etc)
4) Run montecarlo like simulation where process is adjusted back from corner to point to find where things pass.  This also could provide a yield report based on the process sweep.
5) Launch optimization/sensitivity analysis to determine failing device. This may not be practical depending on simulation and circuit.
There are probably others.  Just curious.   I assume it would also be possible to expand on this manually.  Just trying to introduce some automation.
If this is not an option right now.  Is it easy to generate sweeps for failing corners.  Ie change parameters(temp supply) of failing corners to include sweeps and just run that?
B) Guardbanding.
If a corner is near, do similar things as above.  Only this time the sweeps are intended to determine if something is near an edge.  Again sweep temp parameters and maybe process to see if anything falls off sharply.  
Same question about manual control also applies here

By stacyw on August 6, 2010
Sorry for the long delay, Mark.  We've made some changes to our forum interface internally and I missed a bunch of comments.  
Regarding point A), we are implementing something along the lines of 1) and 2) in our upcoming release at the end of this year.  Regarding 3), you can always enable only the failing corners and add sweeps as desired to rerun.  I'm not sure what you mean by 4).  What do you mean by "adjusting the process"?  
Interestingly enough (as a side note), you can get a "Yield" view in the Results panel for any type of analysis in which multiple points were run (sweeps, sensitivity, optimization, etc.) to get the min/max/mean/sigma for all points run.  
I think some of the capabilities you mention would be applications for sensitivity analysis.  You can run SA on any point sweep and/or corner to see the effects of each individual variable or parameter.  You can also start optimization from any point.  Of course, you do need to manually define the relevant variables and ranges first.  We are also working on ways to automatically generate worst-case corner combinations from SA results.
Let me know if you'd like to discuss this further.

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