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What makes an embedded design low power?

Wednesday, March 2nd, 2011 by Robert Cravotta

It seems that nearly everything these days is marketed as a low power device/system. I see it so much in marketing material and in so many unsubstantiated contexts that it has become one of those phrases words that becomes invisible on the page or screen that I am reading. It is one of those terms that lack a set-in-concrete context – rather, it is often used as an indication of the intent of a device’s designers. Is it reasonable to declare an mW device as low power when there are μW devices in existence? Is it ever reasonable to declare a multi-watt system as low power?

The fact that low power thresholds are moving targets makes it more difficult to declare a system as low power – meaning that what is considered low power today soon becomes normal and the threshold of what constitutes low power necessarily shifts.

I recently was asked to build an online course about low power design for a processor that consumes power on the order of Watts. When I think of low power designs, I usually think of power consumption that is several orders of magnitude lower than that. While low power is not defined as a specific threshold, it can be addressed with appropriate techniques and strategies based on the context of the end design. I came up with an energy consumption spectrum that consists of six major categories. Even though the specific priorities for low power are different for each category, the techniques to address those priorities are similar and combined in different mixes.

We will be rolling out a new approach (that will eventually become fully integrated within the Embedded Processing Directory) for describing and highlighting low power features incorporated within microprocessors (including microcontrollers and DSPs) to enable developers to more easily identify those processors that will enable them to maximize the impact of the type of low power design they need.

What do you think is necessary to consider an embedded design as low power? Are there major contexts for grouping techniques and strategies for a set of application spaces? For example, energy harvesting applications are different from battery powered devices, which are different again from devices that are plugged into a wall socket. In some cases, a design may need to complete a function within a maximum amount of energy while another may need to limit the amount of heat is generated from performing a function. What are the different ways to consider a design as a low power one?

Tags: Low Power

This entry was posted on Wednesday, March 2nd, 2011 at 1:49 pm and is filed under Extreme Processing, Question of the Week. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.