Extreme DA keeps a fairly low profile itself. The company first came to light in 2005, when it consisted of four founders working in the offices of Lanza TechVentures in Palo Alto, Calif. At the time, statistical timing analysis was a new technology that was just starting to gain attention for 65 nm design.

Today, Extreme DA sells the XT suite, which includes "variation-aware" timing analysis, interconnect extraction, statistical library modeling, and post-layout optimization. The optimizer is a full-chip product that offers cell sizing.

Mustafa Celik, Extreme DA CEO, said his company bought Xigmix for its transistor-level statistical capabilities. "We are offering a toolset for parametric yield analysis and optimization, and for that you need statistical characterization and optimization for building blocks too," he said. "Those building blocks are standard cells, custom cells, I/O circuits and memory blocks."

Located in Pittsburgh, Pa., Xigmix was founded in 2005 by Xin Li, CTO; Larry Pileggi, professor of electrical engineering and computer science at Carnegie Mellon University (CMU); and Lucio Lanza, managing director of Lanza TechVentures. Pileggi and Lanza also helped launch Extreme DA, and Pileggi was Celik's post-doctoral advisor at CMU.

Li said that Xigmix has one paying customer, and is currently providing a service rather than shipping a tool. However, the company has developed a tool called Road. Based on the company's quadratic statistical modeling technology, it offers statistical performance analysis and circuit optimization.

According to Li, Xigmix technology is up to 10 times faster than Monte Carlo simulation, while providing comparable accuracy. He said it can replace Monte Carlo simulation "90 percent" of the time. It provides all the information Monte Carlo provides and then some, he said, since it can also return sensitivity values.

Xigmix' Road provides performance model visualization, statistical library characterization, and parametric yield prediction and diagnosis. It claims concurrent optimization of performance and yield. Road is integrated with Cadence Design Systems' Analog Design Environment, and it takes in Spectre or HSpice netlists.

Celik said Extreme DA hasn't decided yet whether to offer Road as a product, or to provide transistor-level characterization services. For now, he said, the focus will be on transistor-level characterization of standard cells, I/Os and memories. "We'll decide later what to do with other types of analog circuits, such as RF applications," he said.

Meanwhile, the acquisition has boosted Extreme DA's staff to 17. Terms of the acquisition were not revealed. "We're gaining a lot of expertise in the analog design and modeling area," Celik noted.