Oasis file format support rises as translators roll

Time to say goodbye to the venerable Graphic Design System II (GDSII) layout format? Perhaps. The Oasis file format, which claims to be 10-50 times more compact than GDSII, is gaining broader support from leading EDA tool vendors, with two smaller suppliers having announced new Oasis translation tools.

Oasis Tooling Inc. and MicroEDA Corp. each announced OpenAccess-to-Oasis translators last October. Mentor Graphics Corp., which already offers a GDSII-to-Oasis translator, is adding direct Oasis access to its Calibre tools and is working on its own OpenAccess-to-Oasis translator. Cadence Design Systems Inc. will support Oasis through the OpenAccess translator that Mentor is developing. And Synopsys Inc. is pledging Oasis support with all of its IC physical design and design-for-manufacturing tools, using a homegrown API.

The activity amounts to fairly rapid implementation for a standard that was approved for use in mid-2003 by Semiconductor Equipment and Materials International (SEMI). But the need for a newer file format is great, given the huge files required by nanometer ic designs.

"The transition from design to the mask shop is getting ugly," said Joe Sawicki, vice president and general manager of Mentor's design to silicon division. "People are having to ship 200GB layers. When you have to ship 32 layers to make up the chip, that's a nightmare."

Terabyte-sized data files are coming soon, said J. Tracy Weed, senior director for business development and marketing at Synopsys and president of Bacus, an organization for mask makers, equipment suppliers and mask users. "The GDSII data file has run out of steam," he said. "It's time for something better."

Oasis, developed by SEMI's data path task force, addresses problems that have surfaced with GDSII. Not only are Oasis files more compact than GDSII, but Oasis can more efficiently represent flat data. Data can be directly accessed in Oasis. And while GDSII can handle 16bit and 32bit integer widths, Oasis can handle 64bit fields.

But Oasis is just a step toward the universal data model (UDM), under development by the Silicon Integration Initiative and the SEMI data path task force. Based on the OpenAccess API, the UDM is proposed as a common repository for all design and manufacturing data.

Last October, Oasis Tooling, a startup founded by Tom Grebinski, chairman of the SEMI data path task force that defined the Oasis standard, announced Mosaic, which Oasis Tooling called the first OpenAccess-to-Oasis translator. MicroEDA, meanwhile, announced an Oasis plug-in for its dfm Editor product, offering bidirectional translations not only from OpenAccess to Oasis but also from the GDSII, LEF, DEF, DXF and Mebes formats.

Mosaic is a bidrectional translator that's free to members of SEMI's Oasis working group or UDM working group until June 2005. Oasis Tooling also offers other utilities, including an Oasis linter/profiler, Oasis writer acceptance program, text-to-Oasis writer, Oasis-to-text decoder and reader, GDSII-to-Oasis translator, Oasis compressor and decompressor, Oasis regression tests, Oasis developers tool kit and OpenAccess viewer.

Grebinski, Oasis Tooling's president and CEO, said he started the company to offer a "reference implementation for Oasis—all the tools and utilities that people require to create an Oasis implementation from scratch." He said he founded the company because SEMI had been unable to get suitable technology donations from Oasis working group members, and development of commercial translators wasn't happening in the way that he believed it should.

While the most important translation step is from OpenAccess into Oasis, it's also important to be able to go back the other way, Grebinski said. "If you have a problem with a mask layout and you want to take it back upstream after fracturing, you can do that with Oasis."

While Mosaic is free to SEMI's working group members, MicroEDA's Oasis plug-in sells for under $3,000 annually. But customers are getting more than just a translator, said Simon Garrison, CEO of MicroEDA.

"We have a centralized database, and you can connect to seven or eight different formats," Garrison said. Further, he noted, users can do complete editing of the Oasis files. Users can attach properties, such as critical nets, to Oasis geometry before it moves to the mask shop. The plug-in, available for a free 15-day trial download, also has a bidirectional text translator.

- Richard Goering

EE Times