According to Legend Design (Santa Clara, Calif.), Spice models have become more and more complicated for modeling various second-order effects. New modeling enhancements and geometry-dependent parameters are continuously needed, particularly in the early stage of advanced process development, the company said.

"[The sub-circuit-type Spice model] has caused serious problems of speed and capacity when using with conventional Spice simulators," said You-Pang Wei, Legend Design president and CEO. "Legend has successfully optimized MSIM to offer an accurate and reliable simulation solution for those leading-edge customers adopting the sub-circuit-type Spice model."

Legend Design said the sub-circuit-type Spice model can provide the flexibility of adding new modeling enhancements, especially for proprietary models. Major foundries have recently started to release sub-circuit-type Spice models for nanometer technology, the company said.

Legend Design's MSIM circuit simulator with the sub-circuit-type Spice model optimization is available now, starting at $15,000 for a perpetual license, according to Legend Design.