Auto-waiver software soothes design headaches

Mentor and TowerJazz will demonstrate the application of Calibre Auto-Waivers in Mentor’s booth at the upcoming Design Automation Conference. All foundries have a set of design rules that must be followed by any company submitting designs for manufacture. Frequently, IP suppliers and foundries have agreements to waive a certain design rule check on a particular block of IP. Some waivers are agreed upon during the design phase of an IP and some are new waivers to a silicon-proven IP due to design rule changes that cause DRC (design rule check) failure in the IP.

Unfortunately, when an IP supplier’s customer embeds a block with an associated waiver in a design, DRC violations are identified by the DRC tool, and the customer is forced to review them and get them cleared by the foundry, which takes extra time and energy and can be very frustrating. Likewise, specific design houses may have already agreed with the foundry on modified or waived rules. Both of these issues are addressed by the Calibre Auto-Waivers solution.

When such GDS files arrive at TowerJazz for manufacture, a DRC run is performed before MASK generation. TowerJazz uses the waiver flow to clean all the agreed waivers and show only real DRC errors that should be addressed.

Calibre Auto-Waivers provides automated recognition and removal of waived design rule violations in external IP, eliminating redundant error debugging while ensuring that all waived errors are properly identified during full-chip verification.

The Calibre Auto-Waivers product, a tool that complements Calibre nmDRC, supports automatic waiver management by using waiver information included in the IP library itself, or on top of the standard Calibre DRC design kit issued by the foundry. The Calibre product uses the waiver information to automatically modify its handling of the specific checks and locations associated with the waived rules. The process is fully qualified by the foundry as part of the Calibre product certification for a specific process and rule file.

Through this mechanism, the Calibre product can automatically and accurately remove waived violations from the DRC output, regardless of how or where the errors appear hierarchically. It also reports the violations that are waived, provides information about the waivers to the designer on request, and creates an audit trail of the waived results.

“TowerJazz is expanding our offering into new markets and regions, so one of our key challenges is minimising overall tapeout cycle time while maintaining both flexibility and quality standards,” said Ori Galzur, Vice President of VLSI Design Center and Design Enablement, TowerJazz. “By employing the Calibre Auto-Waivers product in the flow, we can quickly and accurately deal with waivers associated with both IP embedded in our customers’ designs, and customer-specific rules, eliminating problems that could otherwise delay tapeouts.”

“Calibre Auto-Waivers is gaining a strong following because an automatic waiver flow maintains rigorous sign-off checking while eliminating days of wasted time reviewing violations that have already been waived,” said Michael Buehler-Garcia, Senior Director, Calibre Design Solutions Marketing, Mentor Graphics. “The solution gives TowerJazz a way to provide flexibility to their customers while maintaining golden sign-off quality.” Join Mentor Graphics and TowerJazz at DAC for a joint session demonstrating the use of Calibre Auto-Waivers on June 10 at 10:00AM in the Mentor booth (#1432), Moscone Center, San Francisco.