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'Virtuoso Meets Maxwell' is a blog series aimed at exploring the capabilities and potential of Virtuoso® RF Solution and Virtuoso MultiTech. So, how does Virtuoso meet Maxwell? Now, Virtuoso platform supports RF designs, and the RF designers measure the physical and radiation effects by using the Maxwell's equations. In addition to providing insights into the useful software enhancements, this series broadcasts the voices of different bloggers and experts about their knowledge and experience of various tools in the Virtuoso IC-Packaging world along with the nuances of RF, microwave, and high frequency designs. Watch out for our posts on Mondays.

Ever since the very informative blogs about die export and bumps had been published by Kerry and Brian, die export has evolved and it’s time to introduce the new look and feel of the GUI alongside the new features added to bring an abstract view to the next level. The GUI has been redesigned to offer improved usability that matches the evolving use model. The new tab-based GUI has also been made scalable to facilitate the inclusion of further options in the future. On the first tab, specify the bump layer and click OK to get your abstract library ready for a package-level design.

As described by Brian in his blog about the bumps, the cellType of the bumps cells must be set to coverBump or pad. This can pose a problem when die designs are already complete or getting access rights is complex. To ease this process, the cellType can be now set without modifying the bump cell. This can be done by using the SKILL function ciRegisterDevice in the .cdsinit .

Example:
;;ciRegisterDevice(<type> <list of Library,Cell,View lists>)
ciRegisterDevice("pad" list(list("PMIC" "PMIC_bump" "layout")))

Now, let’s move to the advanced features. The advanced settings help you manage how the views will be generated, how an s-parameter model is to be added to an abstract view, or whether the Pin Numbering and Area Transfer tabs should be enabled. S-parameter models are used to create extracted views. You can specify the model file name or model view name and choose to attach models during die export. To add variants of logical parts, which are different in terms of physical part values, you can specify a .csv file. This helps you experiment with the die export results by using various variants to achieve the desired outcome.

When generating an abstract view from an ongoing die design, all the views may be not in sync. As an example, a pin can be added to the schematic but it’s not in the layout yet. To handle such differences in an ongoing design, the third output mode, Generate all views (schematic view when possible) allows to generate an abstract library even if all views are not matching.

When generating a die abstract, pins of the abstract view are set to the terminal names, such as VDD. It’s common to use pin numbers rather than names at an abstract view level. To ensure that you can easily specify pin numbers, there’s a dedicated tab, Pin Numbering, enabled to alter the pin names of an abstract view when the Customize pin numbers check box is selected.

A pin number can either be inherited from the APD_PIN_NUMBER property created on each bump cell or from a Die Text file. The Die Text file contains the bump locations as well as the mapping between the pin names and the pin numbers.
The same format is shared between the SiP Layout Option and the Die Export feature.

Here is an example of Die Text file

It can be interesting to include more shapes in an abstract view rather than just the bumps, such as logo, marker shapes, or any additional shapes. This can be accomplished using the Area Transfer tab. The tab is enabled when the Transfer area check box is selected.

The details of the shapes to be transferred should be described in an XML file. As shown in the example illustrated below, the shapes in Metal2 and Metal3 that have the DieExportTransfer property will be included in an abstract view.

As you can see, the logo shapes on the bottom right have been tagged.

After the die export, you can view how they’ve been transferred to the abstract view.

That concludes our tour of the new Export Die GUI. 

Stay tuned as we’ll share new updates in the upcoming Virtuoso Meets Maxwell blogs.

Related Resources

For more information on Cadence circuit design products and services, visit www.cadence.com.

Rudy Couget and Deepti Mishra Gupta

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About Virtuoso Meets Maxwell

Virtuoso Meets Maxwell series includes posts about the next-generation die, package, and board design flow with a focus on reinventing and optimizing the design process to ensure that the designer remains a designer! Keep watching!

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