Shrinking Power Budgets

So far, top-line power budgets have been relatively flat. That’s starting to change.

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While much of the electronics industry is coming to grips with maintaining power levels and trading that off with performance, most chips have largely lived within a fairly stable power budget. It certainly has gone down over the past decade, but not that drastically. There is certainly more functionality on chips, which makes it much harder to keep SoC power within a fixed number, but at least the top-line number hasn’t decreased significantly.

There are rumblings that’s about to change. Top systems companies are talking about ramping up the pressure to really cut the top-line number as more electronics go mobile. This is significant, because to win a socket—not to mention literally avoid burning the hands that feed even vertically integrated chipmakers—that overall budget has to shrink accordingly.

Some of this will be relatively easy. Many chips already come with sophisticated power management schemes that are rarely utilized by OEMs. Just turning on the features, and turning off more of the chip when it’s not in use, is pretty straightforward. Just changing the substrate to materials such as fully depleted silicon on insulator can help control leakage.

Some of it will be more difficult. A bridge between hardware and software will have to be constructed, which means automation tools will have to dig much deeper into new areas and provide a sort of Rosetta stone that provides feedback to hardware and software engineers about how each development throughout a flow affects the other side. Just being able to provide that kind of detail to software engineers can go a long way in helping reduce power and improve performance.

And some of it will consist of amazing engineering feats like the ones that have dotted the history of semiconductor design. Solving issues such as stacking die, reducing physical effects and being able to do more with less become more difficult as the laws of physics begin playing a bigger role in shrinking designs. We are already at the point where we can see a clear role for carbon nanotubes, graphene, tunnelFETs and atomic memory, not to mention new insulation and manufacturing schemes that are beginning to look more viable. A shrinking power budget runs through all of these schemes, interlaced with business and technology issues and greater integration with a much larger system.

How all of this unfolds, and what a flow ultimately looks like remains to be seen. But power, along with shrinking processes, will force changes in every part of design—and dramatically reduce the silo approach that currently defines the ecosystem. Cutting the power budget will only hasten these changes, and so far no one seems to know what the result will be.