San Francisco — With a circuit simulator that combines both Spice and "fast Spice" capabilities, Magma Design Automation entered the analog/mixed-signal simulation market here at last week's Design Automation Conference. The company's FineSim Pro offering is the first to result from Magma's November 2005 acquisition of ACAD Corp.

Magma quietly acquired ACAD, provider of the FineSim circuit simulation tool, after paying $450,000 in cash and assuming a $3.9 million liability, said Suk Lee, general manager of Magma's custom design business unit. The entire ACAD development team of 16 then joined Magma, said Andy Huang, former ACAD president and CEO, now vice president of business development at Magma's custom design business unit.

When it introduced FineSim in 2004, ACAD claimed to offer more accuracy than other fast Spice simulators on the market. FineSim came to be used primarily by flash memory designers, Huang said, because of its analog accuracy and its IR drop and electromigration analysis capabilities.

Magma thought the technology behind FineSim could be a good addition to its own technology portfolio, Lee said. "As Magma continues to increase its capabilities in the digital marketplace, we need to start servicing requirements of people who are in adjacent spaces, such as the Big A, Big D mixed-signal marketplace," he said. With FineSim Pro, Lee continued, Magma will address large mixed-signal chips with significant analog and digital content.

What Magma has added since the ACAD acquisition is a "trimode" engine. That means the simulator can run in one of three modes — analog, full Spice and turbo Spice — allowing designers to pick the best combination of accuracy and speed for any given block. Lee said that three modes can run at the same time.

In Spice mode, the simulator has full Spice accuracy, Lee said. He also said that algorithmic improvements allow FineSim Pro to run three to five times faster than other Spice simulators. Further, it can be parallelized over multiple CPUs with a near-linear speedup, he said.

According to Lee, Magma has run simulations on 16 CPUs and experienced speedups of nearly 16 times over a single CPU. That's in addition to the aforementioned single-CPU speed increase of three to five times, he said.

"Customers could replace their existing Spice engines with FineSim Pro, but that's not the market we're going after," Lee said. "We're going after the big mixed-signal full-chip marketplace." Today, customers can't simulate in a regular Spice engine, or simulate with more accuracy than existing fast Spice engines, he said.

The analog mode, he said, is comparable to the original FineSim, and is aimed at circuits with hundreds of thousands of transistors. It's much more accurate than existing fast Spice simulators, he said. The turbo or fast Spice mode is claimed to run faster than fast Spice simulators without sacrificing accuracy. But metrics are hard to quantify, he said, because accuracy is design-dependent.

FineSim Pro takes the same models and Spice netlists as other Spice simulators. Output is ASCII or binary, and the FineWave utility provides a waveform display. The simulator also works with third-party waveform tools.

While Magma is integrating ACAD technology "under the hood" in some of its IC implementation products, FineSim Pro is a standalone tool, Lee said. It will ship in August. Lee said pricing will be "comparable" to other fast Spice simulators, but declined to provide more details.