Virtuosity: In the Line of Veri-Fire - Episode 5

Hi readers! Welcome to Veri-Fire, a blog series that helps you deep dive into Virtuoso® ADE Verifier and learn about its various whys and hows. In this series, Walter Hartong, a Product Engineering Architect at Cadence, will be answering some frequently asked questions on Virtuoso ADE Verifier. Stay tuned for some interesting explanations and solutions! And if you have any specific questions in mind, feel free to send those to veri-fire@cadence.com.  
You can find most of the questions that come across to Walter on the Virtuoso ADE Verifier FAQ page, and the list might grow, depending on your questions ! 

Welcome to the fifth episode of the Veri-Fire series. This week we bring to you some questions from intermediate and advanced users of Virtuoso ADE Verifier. If you are interested to know about the previous questions and answers, check out episode 1, episode 2, episode 3, and episode 4 of our Veri-Fire series.  

Rob: What is new in Virtuoso ADE Verifier for IC6.1.8 and ICADVM18.1 ISR13?

Walter: Here, I have created a short video that talks about the highlights of our latest release. You might want to check it out!

Vasant: When I export requirements I see an ID column. What is an ID?  

Walter: The ID - well, this is an interesting question! If you create a cellview from scratch in Virtuoso ADE Verifier and you have 20 or 30 requirements, a unique ID might not be required. But think ahead - if you have 500, or 1000, or maybe even 10,000 requirements, it will be impossible to ensure that all the requirement IDs are unique. You will certainly have multiple requirements which are called "gain",  but how will you tell them apart? The answer is - a unique ID for every requirement. By default, Virtuoso ADE Verifier uses a Globally Unique Identifier (GUID), which is effectively a long random string. You can use your own ID pattern, customized to suit your needs, but I would recommend you to use the default GUID format.

If you import a requirement in Virtuoso ADE Verifier which already has an ID, that's great! You can just provide that ID to the tool during the import. If you don't have an ID, the tool will create one for you.

During the export, Virtuoso ADE Verifier will always add the ID to the exported list. You need to make sure that you keep the ID the same in the rest of the flow (outside Virtuoso ADE Verifier). Using this approach, you can always come back and re-import the requirements again. Virtuoso ADE Verifier will understand which item is identical to what you had before by using the ID.

Vasant: What is the motivation behind the 'Typical Value Setup' form?  I saw that it has to be set up per test.  

Walter: No. Typical value is not per test, but it is global for Virtuoso ADE Verifier. You will find the global setting in the Tools menu. You can populate the typical value set from a test. This makes it easier, because you do not have to type in the details.

There is a parameter combination which defines what typical is, for example:

vdd=1

freq=10M

temp=27

If Virtuoso ADE Verifier finds exactly one result with this set of variables, it will call this result 'typical' and show it in the results. If it does not find this combination, it will leave 'typical' as blank. If it finds more than one combination which fit, it says “various”. In this case, you need to be more specific about your typical parameter set. Maybe you need to add Rout = 100 to find a unique typical value.

It can be difficult to find out why you do not get the typical results as expected. Unfortunately, there is no simple way to find out what the problem might be. In most cases, the parameter combination simply does not match what you have in typical. If you set the SKILL function verifEnableDebug("default") in the Virtuoso CIW and repeat the run or reloading of results, you will see a large amount of debugging messages in the CIW. If you search for the keyword "Typical", you will find the typical parameter definition and the parameter of all the points. You can check the 'Typical Value setup' section in the Virtuoso ADE Verifier RAK for further explanation.

Marcel: I hear Virtuoso ADE Verifier can do analog coverage? How does that work?  

Walter: Check out this video:

Marcel: Okay, I understand now that Virtuoso ADE Verifier can do analog coverage. Can I force it to reload and run with the variables that I missed?  

Walter: I was expecting this question from you! And here's the answer to your question:

Until next time, when we bring to you a few more of such interesting questions and answers!  

Related Resources

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About Virtuosity

Virtuosity has been our most viewed and admired blog series for a long time. The series has brought to the fore some less well-known yet very useful software and documentation improvements and has also shed light on some exciting new offerings in Virtuoso technology. This series broadcasts the voices of different bloggers and experts, who continue to preserve the legacy of Virtuosity and try to give new dimensions to it by covering topics across the length and breadth of the Virtuoso environment, and a lot more. To receive notifications about the new blogs in this series, click Subscribe and submit your email ID in the Subscriptions box.

Happy reading, and stay safe!

Team ADE Verifier