SAN MATEO, Calif. A three-year initiative by library-generation tool provider Prolific Inc. aims to bridge the gap between full-custom and cell-based chip design. Prolific will work with Cadence Design Systems, Get2Chip, Circuit Semantics and Silicon Metrics to integrate the resulting Liquid Cell technology into their tool flows.
Dan Nenni, vice president of marketing for Prolific, said the company has worked with each of the design automation vendors in the initiative to be sure the Liquid Cell technology can create cells on the fly as needed for synthesis and place-and-route.
Nenni said that in a typical synthesis and place-and-route (SPR) flow, a static set of library cells maps a design into its final physical implementation. But if an SPR flow cannot locate the exact cell or cells it needs, it typically will take the next best cell or combination of cells. That often causes SPR tools to overdesign and not meet performance and area requirements. Users that can't tolerate this in their design frequently have to create cells by hand. "With Liquid Cell you can use any standard cell library," Nenni said. "During synthesis and place-and-route those tools tell Liquid Cell what specific cells they need to optimize their design, and then Liquid Cell creates them."
Liquid Cell in SPR flows uses a virtual library concept that represents all possible variations of drive strength, beta ratio and taper factors, Nenni said.
Depending on what the SPR tools can do, he said, the virtual library can be represented as an abstraction or as simply a very large set of cells. Only the cells actually needed by the SPR tools are then generated.
SPR tools take those cells they need to meet their cycle time, area and power requirements. Cells not found in the base library are automatically generated "on the fly" as Liquid Cell.
At one time, Nenni said, Prolific developed Liquid Cell only for Magma Design Automation. But Magma dropped the technology, prompting Prolific to sue Magma. That suit is still in the courts.
Get2Chip said that integrating the Liquid Cell technology into its flow gives the synthesis tool an additional 15 to 25 percent performance increase in terms of speed-driven optimization and similar gains for area optimization.
Prolific is currently working with other EDA vendors that will soon announce the integration of Liquid Cell technology into their environments, Nenni said.