Designers look to 90 nm, and beyond

The pursuit of performance once involved identifying paths with negative timing slack and crafting them. But as designers move to 90-nanometer and finer processes, as some leading-edge design teams will do this year, the scope of the problem widens. Performance is no longer just about static timing. As the articles in this section reflect, it involves just about every aspect of the design process, and demands the cooperation of both design teams and tool vendors.

From managers at IBM Research and at Texas Instruments Inc. come two very different views of the issues 90 nm will present to design teams. One article looks at designing under tight power constraints, while the other examines the problem of performance from the architectural side.

Tool vendors Mentor Graphics Corp. and Synopsys Inc. weigh in on what is perhaps the most-discussed issue at 90 nm: process variations in high-performance chips and their impact on yield. The Mentor article examines the whole question of design-for-yield as a flow issue, while the Synopsys paper zeroes in on the problem of modeling on-die, correlated process variations, and how the models will have to be reflected in libraries.

Magma Design Automation's newly acquired Silicon Metrics group, meanwhile, discusses modeling of the emerging nonlinearities in power-another key issue to getting the libraries right and avoiding iterations (or worse.) And intellectual-property vendor Virtual Silicon looks at the technique of power management by defining power islands-areas of the physical design that will operate on independent power supply voltages, so that individual circuits can be voltage-scaled to just meet their speed requirements.

Finally, the focused-ion-beam (FIB) gurus at FEI Co. assure us that while at 90 nm it's still possible to rewire system-chips on the FIB system, the complexity and density demand that designers consider the needs of the FIB system on the front end, and subtly change the design to make editing possible and effective.

As these articles reflect, performance, like yield, will be a holistic pursuit in the industry's new age.