Variety, from Altos Design Automation, is an ultra-fast, general purpose statistical library characterizer for standard cells. The tool generates variation-aware timing models for use with commercial statistical static timing analysis (SSTA) tools from Extreme Design Automation, Cadence Design Systems and Synopsys. Other formats will be supported in future releases, including the SSTA standard format from Si2′s Open Modeling Coalition.
Variety characterizes for both systematic and random variation. Random variation, which can account for more that 50% of the total variation for sub-90nm processes, represents a significant new challenge to characterization run-time as it requires modeling the impact on each individual transistor within a cell. This could potentially increase characterization run-time by 20X without sophisticated algorithms to enhance the performance. Variety leverages the “inside view” approach that Altos pioneered for Liberate, their non-statistical library characterizer, to keep the overhead of random variation characterization to 3X or less of nominal characterization.
Variety creates SSTA models that include nominal timing information plus additional data representing the impact of any number of parameter variations. All library timing data is characterized for variation including delays, transitions, timing constraints and pin capacitances. Both linear and non-linear models can be created as well as driver and receiver current source models such as Composite Current Source (CCS) and Effective Current Source Models (ECSM).
Variety is available now, U.S. pricing starts at $95K for a 1 year license.