Altos offers its statistical approach as a standard
The statistical approach to designing integrated circuits that was talked about a few years ago is poised to become widely available. Anyway, Altos Design Automation Corporation is ready to provide the Variety statistical library for standardization as part of the Si2 (Silicon Integration Initiative). The company also released Liberate last year, a traditional static analysis tool.
Statistical analysis of pulse propagation time, taking into account the variability of the technological process and allowing to estimate statistical distributions, becomes very important for norms of 65 nm and less. However, one of the problems is the lack of available characterization statistical libraries and the lack of a standard library format. Si2 plans to solve this problem by including developers in the OMC (Open Modeling Coalition). According to Altos, its technology makes it possible to speed up the process of characterizing libraries by an order of magnitude, thus it takes the same amount of time to generate a statistical model as it takes to create a static model.
This, the source notes, is a rather bold statement (and Magma disagrees with it, claiming that their SiliconSmart tool is faster), since when creating a statistical model, you need to take into account variations in many parameters, in particular, each transistor in a cell. Therefore, it often takes 20 to 50 times longer to create a statistical model than a conventional one. If the standardization of Variety within OMC is successful, Altos will have a significant advantage, as the company now has to work individually with vendors of EDA-tools, ensuring compatibility of their libraries with their products. In particular, Altos collaborates with Cadence, Extreme DA and Magma Design Automation, which develop their own statistical libraries themselves, and are also members of OMC.
As Altos explains, a key feature of Liberate and Variety, which generates models up to ten times faster than competing libraries, is the inside view technology, which is nothing more than preliminary analysis of integrated circuits, during which unnecessary simulation vectors are removed. If we compare Variety with Liberate, then if it is necessary to characterize three systematic (for example, the length of the channel, the thickness of the oxide layer and some other parameter of the technical process) and one random (threshold voltage) parameters, then the operating time of the first will be six times longer than the last.