PDF buys silicon IP startup Fabbrix

Looking to weave a new "fabric" for nanometer IC design, yield optimization provider PDF Solutions Inc. has purchased startup Fabbrix Inc., a provider of silicon intellectual property (IP) that promises a lithography-friendly alternative to conventional standard cell design. The purchase helps bring to market a new approach to design for manufacturability (DFM).

Fabbrix is a low-profile startup founded in 2004 by Larry Pileggi, professor of electrical and computer engineering at Carnegie Mellon University (CMU), and some of his graduate students. Pileggi is Fabbrix CTO and acting CEO. Veteran EDA venture capitalist Lucio Lanza, managing director of Lanza TechVentures, is chairman of the board. Lanza is also chairman of PDF's board.

Fabbrix technology employs libraries of "logic bricks" that contain regular structures built from lithography-friendly shapes. Logic bricks, which can be thought of as extremely large standard cells, promise to improve yields, simplify design flows, reduce transistor variability, and make resolution enhancement technology (RET) more effective, without sacrificing performance or power goals. Fabbrix came to light last December when it announced a partnership with PDF Solutions for silicon characterization.

PDF Solutions provides tools and services for yield optimization and learning, including characterization test chips, yield management software, and fault detection and classification software. The company will sell Fabbrix software, services and IP blocks under the name pdBrix as a standalone solution, and as an option to PDF's integrated yield ramp solution, said Kimon Michaels, vice president and general manager for DFM at PDF.

"We think Fabbrix, combined with our DFM capability, really offers a solution to getting better chip area, lower variability, and faster design cycles," Michaels said. Adding Fabbrix' layout optimization capability to PDF's characterization and modeling technology is a "key combination," he said.

Pileggi noted that Fabbrix hasn't shipped any products yet, but is in evaluation mode with some unnamed partners. "It is a little bit early, but we really run this as a technology play," Pileggi said. "We've been working with IDMs to demonstrate our fabric. PDF really broadens the scope of what we can do, and we're really excited about it."

To acquire Fabbrix, PDF is paying $5.6 million up front, with an additional payout of up to $14 million over a period of four years if revenue objectives are met. Fabbrix has around 10 employees, all of whom will join PDF. Pileggi will retain his post at CMU but is taking a leave of absence to help PDF launch the new effort.

What Fabbrix provides, Pileggi said, is a "design kit" that enables the circuit fabric now called pdBrix. "Where PDF comes in is generating the circuits that work well with that fabric and understanding the impact of lithography on that fabric," he said.

Michaels noted that pdBrix are large regular structures analogous to standard cells, and that they come with software that lets designers bring them into standard design flows. It's a replacement for a standard cell flow, he said, not remapped standard cells. "The bricks are significantly larger and incorporate a lot of manufacturability," he said. "The fundamental objective is to let designers go back to being designers, as opposed to trying to turn them into process engineers."

Since much of PDF's work has been with fabs and process development groups, pdBrix would seem to take the company in a new direction. But Michaels noted that PDF has already been working in the DFM area for a number of years, both in library optimization and in statistical characterization of yield models. "It's an expansion of our support base of the design side," he said.

Michaels said he expects both design and process engineers will be interested in pdBrix, and that fabless companies will be able to use the technology too, since many fabless providers design their own silicon IP libraries. "There's a competitive advantage in being more manufacturable," he said.