BANGALORE, INDIA: There is a lack of satisfactory match that needs to be overcome for India to go up in the semiconductor value chain in . This should be overcome by training, adopting new methodologies/tools and taking care of it from the beginning in the design phase, according to S. Uma Mahesh, co-founder CEO of Indrion Technologies, in this discussion on yield management and DFM in the Indian context. Excerpts:

CIOL: It is said that design for manufacturing (DFM) means design for money and design for profitability. What are designers doing about maintaining these? And most importantly, are the designers conscious of yield?

S. Uma Mahesh: I believe, it is not as much as they should! For many who know, it is still not mapped to technical parameters. That is, what if they do will effect the yield to what extent!

CIOL: What is your take on DFM?

SMU: Essentially, it implies that the design takes care of the effects of manufacturing, by factoring for it in all phases of design -- beginning with architecture. This is done in terms of design margins, matching the projected performance numbers to those achieved.

This requires designers to factor for it, primarily the cross talk, electro migration, signal 'bouncing', etc., by planning for the power bus, clock bus architecture, their widths. And similarly, at the frontend level, by planning for the margins in timings, clock skews and latencies. The teams are increasingly planning for these from different stages of frontend design and also in the physical design planning and later, by using tools that are actually aware of the DFM, SI effects, respectively.

CIOL: Why aren't designers as conscious of yield as they should be? If not, why and what should they do to improve?

SMU: I believe that it has more to do with 'realizing the importance of design decisions on yield'. As we know, these (DFY, DFM) are new developments, that are of higher importance for some designs over other -- for example, for high frequency, high performance, lower geometry designs.

I believe that more importance should be give to these aspects by companies when they train their engineers. Most of the education does not yet deal with it, and it seems that some modern, young engineers are not quite eager about basic fundamentals. So, the amount of related reading that they do is lesser than earlier. Of course, work requirements allow lesser time, but that should not be a reason.

Therefore, companies should try to incorporate these aspects in training and inculcate the importance of these to the engineers, explaining the importance of these factors to the products they develop. In short, more education of the factors are required.

CIOL: Is the yield accurately mapping into the technical parameters that would ultimately lead to higher tapeout percentage? What are the challenges and how can those be overcome?

SMU: Not yet, I believe. This is because of some reasons, as given here.

The essential tools are in the process of becoming part of the design process and they do a good job. However, this is still an evolving space, and hence, lots of opportunity for EDA tool companies, startups, as can be noticed in the industry activity globally.

Hence, more tools are required, which means the current solutions are not quite there 100 percent It should be noted that all tools cannot be straight away used by the companies. There is a process, the tools have to stabilize etc., and there are a few options to evaluate.

Therefore, more than many other aspects of designs, the architecture, design have to envisage these effects from the beginning and try to derive the best from the existing tools that they use.

In fact, the design teams and companies develop their own tools/routines/scripts to extract the best out of the existing tools. This approach will need to continue (now EDA is in transition, with internal tool/EDA related activities being very important).

So, the companies should continue such internal approaches -- of training their employees, internal development of some.

Equally important is the need for design managers to be more open about new approaches, new tools and new methodologies. This is where, I believe, our design managers should do better. As any EDA company can testify, there is a 'conservatism' (while understandable) about the need to try new tools to improve productivity, while increasing the accuracy. Many design teams, unless they feel really compelled (forced from the very top, outside India), restrict themselves to earlier methodologies and try to improvise through extra efforts rather than with extra intelligence.

Hence, the lack of satisfactory match (that has to be overcome for India to go up the value chain) should be overcome by training, adopting new methodologies/tools and taking care of it from the beginning in the design phase. A multi-pronged strategy is required.