MBG’s Observations on a Changing Design Solutions World

Observations on the changing environment facing chip designers as they move into new process nodes and engage in new market requirements.

9 November, 2009

 When I was at PDF Solutions we launched a campaign that stated DFM is now the designer’s problem. It was not a resounding success as at 90nm, the majority of designers simply stated, “No it isn’t—it’s the fabs problem.”

 While DFM was evolving and the major wrinkles were being ironed out, designers enjoyed a “grace period” when the dangers of not doing DFM checks were perhaps overstated, and the practical reality of who was responsible was at best shared. But realistically, it was the fab’s responsibility unless proven otherwise.

 Now major foundries have essentially served notice to the industry—the implied contract between the foundries and their fabless customers is changing, and DFM is now the designer’s responsibility. This applies not only to SoC designers, but to IP design teams as well.

 Foundries  are indicating in their various ways that the responsibility for doing DFM checks, and making sure a design is optimized for manufacturing, lies with the designer. TSMC has been doing education seminars with Mentor on DFM and has made model-based litho and CMP checks mandatory at the 45/40nm node, with CAA checks highly recommended. Chartered Semiconductor, working with ARM and Mentor Graphics, has developed a methodology for DFM scoring of IP, and has made DFM scoring a requirement for IP that will be purchased by the Common Platform at 32nm. SMIC is making DFM checking a requirement at 65nm and below for all three DFM functions litho, CMP, and CAA.

 At the Mentor-TSMC DFM seminars there were multiple questions from the attendees about what “mandatory” truly meant, arguing the fine points of one scenario vs. another.  What the audience was not grasping was that the implied contract has changed from “if there is a yield problem after DRC signoff, it’s the fabs fault” to “unless you have data verifying a DFM-clean design, it’s the designer’s fault until proven otherwise.”

 The nature of the customer-supplier relationship is such that the foundries are reluctant to force new requirements, that admittedly have associated cost and time impacts, on their customers. However, they are being very clear that if a customer chooses not to run the recommended DFM checks, and yield problems surface during first silicon or later, the burden of proof will be on the foundry’s customer to show that the design is DFM clean.

 So, like it or not, if you’re moving to the most advanced process nodes, start thinking about DFM the way you are used to thinking about DRC.

 For more on this topic, see Simon Favre’s blog post, “What Do You Mean by Mandatory?” at http://www.mentor.com/products/ic_nanometer_design/blog/post/what-do-you-mean-by-mandatory–5d73a87b-729d-4e52-bf90-90844ee96189

8 September, 2009

Every so often it seems like we get a rash of “free trial” or “free software” offers in the EDA industry. Of course, in consumer goods where it makes a lot of sense, a free trial is one of the staple weapons in the marketing inventory. If you want someone to try a new or improved product that doesn’t require a big investment in time or effort to use, it’s a compelling way to generate interest. The question is, “Does it make sense for complex EDA software?”

Replacing a product that is a core part of a complex design flow must be handled differently in order to manage the costs and risks associated with change. Evaluating a sign-off tool is a complex undertaking requiring assessment of a range of key criteria, such as robustness and scalability, reliability, runtime performance, foundry rule deck support, compatibility with third party tools, price, and so on. A decision based on only one of these factors will probably be the wrong decision and could risk the company’s core objective of shipping product on time with competitive performance. Other potential penalties could include extended product development cycles, higher cost of quality, and ongoing support risk if the long term viability of the vendor being evaluated is in question.

 With this in mind, does a “free trial period” really provide much value? Considering the amount of time a team expends in developing and running an evaluation itself, along with the support cost of changing a tool, the purchase price of a 30 or 60 day license is immaterial. Besides, EDA vendors provide free temporary licenses for evaluation all the time without advertising them as free trials. To me, the issue is not providing free licenses for evaluation, it is understanding the evaluation criteria, and providing the technical support to ensure that a new user is truly taking advantage of the product’s capability.  In fact, I would caution buyers to be wary of free trial approaches because they are often fishing expeditions; your chances of getting solid vendor support for such a program is lower than if you set up a formal evaluation process. Falling prey to a quick trial because the software is free, but which ultimately proves to be a poor choice, is probably not career enhancing! As much as the EDA industry would like to think otherwise, our customers are in the business of delivering their products, they do not have the luxury to do multiple evaluations all the time.

What do customers really need to help them make the best decision for their business? They need evaluation licenses combined with vendor support to cover all aspects of a thorough evaluation process. Assuming the decision is to switch, they also need post-sales support for training, configuration and integration into their flow. All this needs to be provided with the same level of enthusiasm and the same vendor team that was with the customer during the evaluation.

A free “do it yourself” trial offer sounds good on the surface, but it can be a hollow promise if the other facets required to succeed are not also available. Bottom line, take the time to develop a well thought out evaluation process and, trust me, you will not only have a successful event, the evaluation software will be free too!

Let me know what you think about free EDA software trials and or formal evaluations. What worked and did not work for you? What do you really need from EDA vendors to help you make product choices? Lets chat!