The Si2 Low Power Coalition (LPC) quietly approved CPF version 1.0 as an Si2 "specification" in the weeks following its donation by Cadence Design Systems Dec. 4. The approval came to light Friday (Jan. 12) as the LPC issued a request for technology (RFT) to complement the CPF.

CPF has been the subject of a bitter dispute since Cadence introduced its Power Forward Initiative in May. Cadence's primary EDA rivals felt this initiative wasn't open and inclusive, and they joined another coalition of companies in the Accellera UPF effort in September. UPF received donations from Synopsys, Mentor Graphics, and Magma Design Automation, and began work on a rival spec.

The Si2's LPC was set up in October in an attempt to bridge that gap, and to examine power issues throughout the IC design flow. However, Synopsys and Mentor Graphics, key backers and contributors to UPF, did not join. Cadence, which had been intending to take CPF directly to the IEEE, donated CPF to LPC, but its rivals continued to work through Accellera.

Si2's approval of CPF 1.0 does not constitute taking sides, said Sumit DasGupta, senior vice president of engineering at Si2. "We declared it a 'specification' and not a 'standard' as a conciliatory offer to Accellera, because we didn't want to inflame the rhetoric by declaring it a standard," he said. "We can now start a dialog with the UPF technical committee to see how the two [CPF and UPF] can be merged into a single spec before going to the IEEE."

The CPF 1.0 specification is currently available to LPC members, and will be available to the public after a 60-day patent exclusionary period closes March 3, DasGupta said. The 60-day period is standard Si2 policy to avoid patent conflicts. He noted that all rights to CPF are now held by Si2.

The Si2 announcement "is a good move to help promote market adoption of a single low power standard," said Karen Bartleson, Accellera secretary. "Si2's LPC is ensuring that there's nothing missing during their exclusionary period for CPF. The RFT is not intended for Accellera because we're already working together with Si2 to converge UPF and CPF into a single standard. We look forward to an even deeper relationship with Si2 and the LPC after their patent disclosure exclusionary period closes."