A better, faster, smarter way to insert filler cells in P&R

By Design With Calibre

By Fady Fouad, Jeff Wilson, Esraa Swillam – Mentor, A Siemens Business

Filler cellsThose cells inserted by the P&R tool to fill gaps in the layout after placement and routing is completed. Filler cell insertion must be completed before physical verification can begin.

Problems with filler cellsFiller cell insertion is a lengthy process, and has to be repeated with every logic or timing change. Plus, the P&R tool uses a limited set of design rule checks (DRC), which usually results in DRC errors that add time to the physical verification schedule.

SolutionUse a different tool that can complete the filler cell insertion process in far less time while also producing DRC-compliant results, enabling designers to start physical verification hours earlier.

The Calibre YieldEnhancer PVReady flow is a push-button solution that leverages the proven Calibre SmartFill functionality in conjunction with foundry-qualified Calibre rule decks to insert correct-by-construction filler cells into the design within a P&R flow. By replacing the P&R filler cell insertion with the Calibre YieldEnhancer PVReady insertion flow, design companies not only reduce the time it takes to place filler cells, but also ensure a DRC-compliant and electrically correct layout.

In tests, using the Calibre YieldEnhancer PVReady functionality yielded a consistent runtime that was nearly independent of the design size, and generated a 6-16X reduction in runtime per design iteration. On average, the PVReady solution made the design available for physical verification within 20 minutes of providing the P&R data in the OASIS/GDS format. Compared to the 4-6 hours typically required by a traditional P&R with filler cell insertion flow, the time savings are pretty obvious. Even better? Because filler cells must be placed after each ECO (both logic and timing changes), this runtime savings is additive for each iteration through the design flow.

Want to learn how your company can benefit from the PVReady flow? Download a copy of our technical paper, Reduce the time delay between P&R and physical verification, to get all the details. Replacing inefficient, imprecise processes with smarter, more accurate, and faster functionality can improve both your bottom line and product quality.

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This article first appeared on the Siemens Digital Industries Software blog at