Sorry to see that the custom implementation group at Mentor is so negative about OpenAccess - not an opinion shared by the Calibre group as a couple of other people have pointed out. I am not sure what "universal acceptance" is, but OA is at least partially adopted by many EDA companies (Synopsys, Magma, SpringSoft, Jedat, Cadence, etc) and major IC companies (Intel, IBM, ST Micro, TSMC, Samsung, etc).
As Ed Petrus pointed out, the code available from Si2 is a reference implementation of the OA standard. Any company is free to create their own implementation (as is being done now with scripting language bindings) or modify the reference implementation source code. Another EDA company I worked for made several major changes to OA and have those in their production code. The only requirement is that any code modifications be contributed to Si2. There is no requirement to wait for contributed code to show up in the reference implementation before shipping it in a product.
Last, curious comments in the article about router integrations in OA. Many EDA companies (Magma, Pulsic, Cadence) have router integrations that translate from OA to another data structure and back. Since both the source and target databases are controlled by the particular EDA company it is much easier to maintain complete data integrity and performance is excellent. SpringSoft and Pyxis (now owned by Mentor) have a very mature shared runtime memory integration in OA for Pyxis NexusRoute-HP. As for OA not working well for DRC, here is a quote from DeepChip "Springsoft and Mentor working together to enable full signoff DRC check in a DRD style environment. Calibre run[s] in seconds in the background every time you unselect a polygon in Laker based on layer. When layout is complete it's 100% DRC clean." Full sign-off DRC checks in seconds sounds like pretty good performace to me. Unfortunate that Mentor Deep Submicron Division (analog) isn't on the same page as the rest of Mentor.
On Multi-threading: Ciranova’s device placer – Helix - is fully multi-threaded and works fine with a non-thread safe OpenAccess.
Helix has been in production making ICs for at least 2 years. A sound architecture and careful implementation is a prerequisite.
As of this year’s latest release of the reference implementation from Si2 (oa22.41p004), support for multi-threading is explicit
(announced at the October 2010 OAC). So Linda’s comment on multi-threading is not well informed.
A typical situation we find at our customers involves layouts generated by Helix that are subsequently analyzed by Mentor’s
DFM tools. Helix populates design databases with layout views and Mentor’s world class DFM tools analyze the layouts
for DR & LVS correctness and subsequently extract post layout netlist for simulation. Such flows are OpenAccess based and
no data translation is required between Ciranova and Mentor’s DFM tools. Typically, such designs are also PyCell/iPDK based
which implies the design data is open to all other OpenAccess tools.
This comment concerns a few technically inaccurate statements in the article above.
OpenAccess is a specification of a schema for representing electronics design data.
OpenAccess as such is not a database.
The distribution we all receive through Si2 is a reference implementation for the schema expressed in the OpenAccess spcification. It happens to be a very good implementation – probably one of the best designed and implemented software in EDA.
Many tools in production rely on OpenAccess for advanced design.
A design database comes about when design tools populate a design library with the many representations possible in OpenAccess.
OpenAccess also represents and controls the architecture of design libraries.
Many tools can manipulate the design database - sometimes simultaneously, aided by design management tools. Viewed this way, an OpenAccess design database is a “centralized database” and this model has been in play for a long time.
Almost taken for granted.
If by “centralized database” Linda is referring to in memory data model accessed by multiple tools then I’m aware of at least one case where OpenAccess based tools from different companies work with one in memory image of OpenAccess design data. Although, this level of tight integration is not always necessary.
The reference implementation is not a requirement to be OpenAccess compliant. It is possible for a company/tool to undertake their own development of an implementation of a certain aspect of the OpenAccess specification. I'm aware of at least one case where this was done successfully.
The OpenAccess effort by Si2 is forging ahead in 3D/Stacked chips as well for standardizing chip power, thermal & stress models. But if a decade of so called cooperation hasn't yielded the results one had hoped for, what is the motivation for established as well as startup EDA tools providers to contribute? Are we just throwing more into the mix fully knowing & expecting an outcome we don't like, I wonder...
Dr. MP Divakar
Here's an article from the latest issue of Electronic Design which gives details on the different ways of using OpenAccess and the success companies have had
Mentor is horribly schizophrenic on OA. Calibre supports, analog tools do not (maybe some weak translation). Analog tools continue to gimp along on AMPL, a language developed back in the Falcon Framework days.
To build a best in class interoperable product, you don’t need OA in-memory database, but you absolutely need to use OA API.
If you have a product that uses in-memory OA database but does not add any more value than the incumbent, then you are not going to overcome user inertia to adopt your product. Your product needs to provide value (productivity or quality of design etc.) while providing interoperability using OA API. That's how we are making our Titan customers using OA successful.
Accellera has, what,14 member companies, Si2 has over 100, who more represents the industry? Just look at the Si2 Board of Directors, and yes, Cadence and Synopsys are both on there.
Gee, here's a nice article from Mentor Graphics' web site which starts out like this:
"Now that almost all of the major custom design tools run on OpenAccess, we often get asked about how well Calibre supports OpenAccess (OA). The truth is that Calibre has supported reading polygonal data from OA since February 2007 and we have kept up with the new releases of OA as they come along" Here's the full link, you'll probably have to cut/paste it, but if a problem, just go to Mentor web site and search for OpenAccess.
Blog Doing Math in FPGAs Tom Burke 23 comments For a recent project, I explored doing "real" (that is, non-integer) math on a Spartan 3 FPGA. FPGAs, by their nature, do integer math. That is, there's no floating-point ...