Low Power to the People - Embedded.com

Low Power to the People



Low Power to the People

Lindsey Vereen


We have seen the future and it is portable. Electronic devices in increasing numbers are being liberated from their power-cord tether. Several years ago at the Custom Integrated Circuit Conference in San Diego the keynote speaker bewailed the fact that although portable computers were getting smaller and lighter, you really needed a suitcase-sized battery to keep them going for any length of time. Advances in battery technology and power management have improved the situation somewhat, but the problem has not gone away.

There has been ample evidence that battery life is important to consumers. The first ubiquitous portable radio was the transistorized radio introduced in the mid 1950s. True, there had been portable radios before that time, tube radios that went through C batteries like popcorn. But transistors gave portable radios the size and flexibility that launched them on the journey that led to the Walkman, the Watchman, and the Discman.

It's certainly true, as well, for hand-held devices like PDAs that battery life is important. The Palm Pilot beat Windows CE devices all hollow despite its modest feature set. What it does have (aside from the applications and interface that work for most people) is a parsimonious way with batteries.Low power consumption is important for cell phones as well. That may be one reason the current generation of digital cell phones (and by current generation, I mean the ones you can get for free or nearly so when you sign up for long-term service) have come into their own. Talk and standby time have made significant advancements over the previous generation of phones, which could never stray too far from the recharger.

As semiconductor technologies shrink, yielding even more transistors on a die, it seems to follow that you can have a lot more software and computing power and still keep costs down. But bigger, faster processors and lots of memory have a deleterious influence on power consumption, so the traditional embedded requirements for processor and memory have not gone away.

Desktop architectures will have a difficult time making the transition to portable devices because of their processor and memory requirements. Although Windows CE has been ported to architectures that are less power hungry than x86 processors, the devices are still power hogs.

The attractiveness of a recent Transmeta announcement (see www.transmeta.com/news/) is that it heralds a possible way to bridge the gap between the desktop and your pocket. The Crusoe chips, as the Transmeta devices are called, have a claimed ability to make batteries last about twice as long as their Intel counterparts and can “learn” about an application while it runs and use that experience to extend battery life.

However, Transmeta is not the only company vying for the mobile computing and post-PC business, and it will have a lot of competition from other embedded architectures. Moreover, a number of strategies including software solutions are being implemented to reduce power consumption.

What does seem clear, though, is that soon you will be able to take it with you. But you may have to leave Wintel behind.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.