Many people are unaware that after donating the OpenAccess database to the Silicon Integration Initiative (Si2) in 2002, Cadence has continued to maintain, revise and improve the OpenAccess reference implementation at its own expense. A recent Si2 award brought this contribution to light, and this blog post fills in some of the details.
The Si2 news announcement said the award was given to Cadence "in recognition of its sustained contributions in developing, donating, maintaining, and improving the OpenAccess standard and associated Reference Implementation." It went on to note that:
"Since the initial donation in 2002, Cadence has provided hundreds of thousands of engineering hours to the semiconductor industry in creating advanced functionality to the OpenAccess components. As integrator for OpenAccess, Cadence has been responsible for implementing the advances proposed by OpenAccess Coalition members through the Change Team, providing the EDA industry with its first interoperable database."
Here's some quick background. Cadence began work on a database called Genesis in 1999. This work provided the foundation for OpenAccess, which was donated to Si2 in 2002 as the reference implementation for the emerging OpenAccess standard. The first production release, OpenAccess 2.0, was released in 2002, and the current 2.2 release came out in 2004. The OpenAccess Coalition currently includes 46 members including Mentor Graphics, Magma, and Synopsys. The Change Team, responsible for maintaining the standard, has 11 members.
To get some more information about the Cadence OpenAccess development team and its current efforts, including the adoption of multi-threading, I talked to two of its members. Michaela Guiney is a Cadence product engineering director and is also Cadence's representative to the OpenAccess Change Team. Mark Hahn is a distinguished engineer and lead architect of OpenAccess.
Why Support OpenAccess?
In general, Mark noted, Cadence is responsible for integrating all the changes that are made to the OpenAccess reference implementation today. Big changes, like the move to multi-threading, are approved by the Change Team. So why continue with this effort, which has seen other EDA vendors, including competitors, adopt OpenAccess?
"We want to satisfy customer needs for interoperable flows," Mark said. "Customers want flexibility, and OA offers a means of providing interoperability. Also, OA is the basis for internal CAD development within some of Cadence's biggest customers."
As noted in the Si2 award press release by Dave Desharnais, group director of product management at Cadence, OpenAccess is also a key element in the Cadence Silicon Realization strategy. This was vividly demonstrated at the recent CDNLive! Silicon Valley, where Dave showed unique mixed-signal design capabilities made possible because both the Cadence Virtuoso and Encounter platforms run on OpenAccess.
What's Next for OpenAccess?
As Michaela showed in a presentation at the recent Si2 OpenAccess Conference (presentation available here), significant changes are in the works for the 2010 OpenAccess 22.41 release, expected around the end of the year. Chief among these is multi-threading, which will allow OpenAccess-based applications to take advantage of multi-core platforms. (An earlier implementation of multi-threading was added in the older 2.1 release, but that release was not widely used).
The goal with the current release, Michaela said, is "to do [multi-threading] in an incremental way that won't destabilize the core." The implementation includes two multi-threading modes: multiple reader threads that run at full speed with no locking, and a single writer thread per database. Applications do some pre-conditioning to make sure threads don't collide. More information is available in a presentation by Alex Wong of Cadence, available at the Si2 web site.
Also new in the 2010 release is "unused string and name cleanup," which will help reduce database size, Michaela said. Finally, 32nm physical layout constraints have been added to OpenAccess, which previously supported constraints down to 45nm. The upgraded support includes new concepts in 32nm layouts such as variable sized cuts, complex end-of-line rules, and spanning rules.
Before anything goes out the door, the Cadence OpenAccess team runs exhaustive testing. That's where being a broad-based EDA vendor really helps, Michaela noted.
As for the Si2 award, Mark said, "it's a nice recognition for the team. Many people here have been working on OA for a long time, and it's a nice recognition for those people in particular." Michaela added that "I think our developers have a real sense of responsibility. Companies and people in the EDA space use this stuff."