Design teams concerned about managing two different power formats will find some relief July 26, 2009. That’s the date of a Low Power Coalition (LPC) workshop that will present some ongoing work aimed at interoperability between the Common Power Format (CPF) and P1801 (Unified Power Format). The workshop will also unveil a new idea -- an Open Power Data Model that could potentially support both formats.
The user-driven LPC, managed by the Silicon Integration Initiative (Si2), not only oversees CPF but has also defined a reference flow for low-power design and is tackling ESL power modeling issues. That will all be explained at the free workshop, which is scheduled for the Sunday before the Design Automation Conference at the Moscone Convention Center in San Francisco from 1:00 to 4:30 p.m.
One session at the workshop will report plans and goals towards interoperability between CPF and P1801. A summary of the goals can be found in a CPF 1.2 roadmap presentation on the Si2 web site. They include identifying a set of commands and options that can be used in both CPF and P1801, resolving ambiguities bewteen compatible subsets of the formats, and providing name mapping between CPF and P1801 objects.
Qi Wang, senior architect at Cadence and a presenter at the workshop, said the basic idea is to define an interoperable subset of the features supported by both CPF and P1801. “If you keep within that subset, potential issues with interoperability will be minimized,” he said. Further, the subset will make it easier to develop translators between CPF and UPF. Work on the subset is ongoing and may be completed later this year.
Another possible approach to interoperability is represented by a proposed power intent data model and associated API. Called Open Power Data Model, it’s intended to work with the OpenAccess (OA) API and data model. The intent is to allow design teams to build automated low-power flows regardless of the power formats they use.
“The notion is that the formats will become an input/output way to get into the data model, in the same way that LEF/DEF is an input/output format into OA,” said Nick English, vice president of development at Si2. The result? “You’ll get out of the format wars. And you’ll be able to build an entire power-aware flow such that each tool can access the power information using OA.”
Sumit DasGupta, senior vice president of engineering at Si2, described the data model as a “neutral container” that can accept different file formats. But it will take some time to implement. He said that LPC members have been doing a lot of “deliberate thinking” about how to resolve syntactic and semantic differences between the two power formats. Also, the data model doesn’t determine how the tools will actually make use of the power data.
Finally, the workshop will include a presentation about ESL power modeling. LPC’s work in this area follows its publication of a low-power reference flow. The development of the flow exposed a lack of power models, particularly at the system level. A Modeling Working Group was established to tackle the problem. Jerry Frenkil of Sequence Design will present its latest work.
A “what’s next in low power” panel promises to be interesting as well. One topic that’s likely to come up is adaptive power management, in which chips can evaluate the external environment and scale voltage or frequency accordingly.
In addition to the low-power workshop, Si2 is offering a free workshop on DFM challenges at 45 nm and below. That workshop will be held Monday July 27 from 1:00 pm to 3:00 pm at the Moscone Convention Center.