Speeding Up or Slowing Down

One of the big questions at DAC this year was when would Moore's Law end. Yes, we have heard this prediction so many times and at each node, some new piece of technology comes along, a new process, a new material — something happens to save the day. But this year there was almost desperation in the voice of many and the reasons given for its end are diversifying. I heard reasons that ranged from economic, to physics, to practical limitations associated with getting new devices (if they exist) ready in time for production when the crunch comes. I heard people saying that this is being brought up as a potential national security crisis. Others seem to still be happy saying that someone will fix the problems and we will all be fine.

Unfortunately there is no equivalent of Moore's Law for analog. I am not saying that analog densities have not been getting higher, but it doesn't appear as if there is a unifying set of issues and challenges that the entire industry is trying to solve, almost collectively. Maybe that is just because I am not in the in-crowd, but as I Google information related to analog, I find so many conflicting pieces of information. Even within the same company, there can be highly disparate viewpoints, but the companies are not important here and I am not picking on anyone.

Let me give one example of a disagreement. I will start with a keynote given by Joachim Kunkel, general manager of the Synopsys Solutions Group. He said that adoption of new technology nodes has been fairly consistent up to the 32/28nm nodes, but now there is a slowdown. Contrary to that, Wally Rhines, CEO of Mentor Graphics, said at DAC this year that “If you look at the last four or five process technology nodes, you will note that the pace of adoption has accelerated.” So which is it?

Perhaps they are both right. Perhaps it depends on the types of design you are doing. While Rhines was looking at the primary SoC market, Kunkel was talking about mixed-signal designs and in particular the difficulties being presented for the analog portions as they migrate from 45 to 28 and from 28 down to 20nm.

So why do we have this separating of the ways? Kunkel believes that it is because of the rules that are being defined at the finer geometries, rules that are perhaps more difficult for analog circuits to adhere to than digital. For example, at 28nm double patterning becomes necessary and with it more stringent rules regarding poly and metal densities that must be kept uniform across the die.

For digital this may just mean adding dummies and a little bit of area goes to waste, but for analog, it is imperative that matched devices are contained within areas of the chip that have consistent densities — otherwise their parameters will drift from each other. It appears that any separation between digital and analog fundamentally comes down to the way in which the rules can be created, understood, incorporated into designs, and automated. So perhaps this shows that more investment is needed in analog tools if those portions of the design are not going to be the thing holding us back from getting to the edge of Moore's Law and seeing what lies beyond.

Do you believe that adoption of new process technologies is slowing down for analog while speeding up for digital? What do we need to get analog back on track?

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4 comments on “Speeding Up or Slowing Down

  1. Netcrawl
    July 4, 2013

    @Bill that was great thanks for sharing it, I'm pretty its going to replace the analog, today's market demands manufacturers build smaller components with more integrated functionality, better product efficiency and competitive advantage.

    Today's engineers are spending more time and attention on new materials and structures, trying to look for new development and efficiency- I think replacing an old methods or technology with new one is crucial to industry's survival and growth.  

  2. Vishal Prajapati
    July 5, 2013

    I think it is some what true that adoption to new technology is speeding up for digital. But we cannot ignore the development on side of analog in the era of Software Defined Radios and Direct Digital Synthesis. These are the devices that are available now, which were just dreams few years ago. So, there is definitely a development on both analog and digital side. There is mixed signal domain which is emerging. Probably there should be a Moore's law for mixed signal ICs.

  3. D Feucht
    July 5, 2013

    Brian, you ask a profound question. To answer it, perhaps the screen needs to be moved back a ways to look at the larger picture. That picture, to me, shows a certain amount of tunnel vision in the electronics industry, in the singular drive (or mad rush, if you will) toward smaller, denser ICs, and neglect of what to do with all those transistors. I would rather have 200 nm transistors and some clever, innovative circuitry than more transistors than I know what to do with that are overly constrained by quantum effects.

  4. BrianBailey
    July 7, 2013

    I think the economics for the digital part of the design has been the drive up to this point. More transistors on a chip means cheaper transistors in general. In the bigger picture this also means greater opportunity for integration. Mors of what were oin seperate chips are now within one chip and so this eventually created the pull to bring abalog on chip as well. But if analog does not scale in the same way, then while there is the pull for greater integration, there is a push becqause analog will consume a greater percentage of the chip area, meaning that its percentage of the total cost will rise. So, the balance point is tricky and involves not just cost, but overall system performance – will the extra slowdown of going off chip bring the performance below a necessary threshold. 3D IC may help solve this problem but today it is too expensive a solution for most people and situations.

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