Avanti improves Star-Sim mixed-signal simulator

Avanti improves Star-Sim mixed-signal simulator
By Stephan Ohr, EE Times
May 24, 2000 (11:38 a.m. EST)
URL: http://www.eetimes.com/story/OEG20000524S0011

FREMONT, Calif. — Avanti Corp. calls its Star-Sim XT the fastest, most accurate mixed-signal IC simulator to date. It provides transistor-level simulations and runs up to 10x faster than the company's original Star-Sim. The simulator is intended for very large system-on-chip designs featuring analog and mixed-signal circuit elements.

"We are trying to address two issues with Star-Sim XT: capacity and performance," said Douglas Lundin, marketing director for mixed-signal products at Avanti. "We've simulated circuits with over 300 million design elements."

The XT algorithm adds full multithreading to the original Star-Sim simulator. It automatically builds a hierarchy of circuit elements, allowing some to be examined by HSpice models and others to be visualized in block mode, said Kevin Kerns, who heads the Star-Sim engineering effort. This provides an order of magnitude run-time improvement for most ICs, 100x speedups for many simulations.

Star-Sim XT is useful in post layout verification for extracting and analyzing interconnect parasitics. Previously, digital designers had to rely on static timing analysis rather than full-chip dynamic simulation. They traded simulation speed for accuracy. Star-Sim XT runs almost as fast as a static timing analyzer — but spots the dynamic errors that often elude other tools, said Kerns.

Milkyway connection

Star-Sim XT is tightly integrated into Avanti's 64-bit Milkyway database. It has a shared-database compression algorithm for increased capacity. To facilitate post-layout analysis, it factors in not only the detailed standard parasitic format (DSPF) file, but also the netlist to preserve hierarchical data.

DSPF files are often large, since they have a considerable amount of redundant information for the circuit simulator. "Just shuttling the data around can take some time," said Kerns. DSPF files are also usually flat and lack the hierarchical information needed for debugging and analysis, he said.

Star-Sim XT effectively pulls the parasitic models from the DSPF files and back-annotates them into the HSpice netlist, making it easier for the simulator to provide detail from an otherwise flat netlist. That flow allows full-layout transistor-level accuracy while increasing capacity, analysis capability and ease of use. Star-Sim XT accesses Milkyway LVS data to allow users to control the simulation and probe voltages and currents using the schematic netlist names, while simulating the extracted DSPF file.

The Star-Sim XT simulator is available now, and is available as an option for existing Star-Sim users. The company has not released pricing.