Configurable Thoughts

 

Sensing Your World

Sensors are becoming more prolific and changing the way that you interact with your world. That smart phone in your pocket is a good example. A lot of what you can do with it is the result of sophisticated sensors that are built into it. For instance, the accelerometer inside determines the orientation in which you are holding the phone so the screen can switch making it easier to read. It also makes games that you control by moving the phone and applications like a bubble level possible. The accelerometer is actually a very sophisticated piece of technology, which is true of many of the sensors that are being developed today.

Controlling this new generation of sensors and interpreting the information that they generate requires a lot of compute power. This is increasingly being done with a 32-bit processor. The challenge is that the processor has to use almost no power and has to be infinitesimally small. The power consumption of a cell phone accelerometer is typically less than 100uA for the whole sensor. The processor has to use less than this but has to be able to process the necessary information in real-time. This requires a new class of 32-bit processor, and is one of the reasons that Synopsys developed the ARC EM family.

Targeted at sensors and other deeply embedded applications the EM family offers almost twice the performance of the processors used only 5 years ago to run a cellphone. The EM family does this while fitting into spaces as small as 0.01 mm2 and consuming as little as 2 uW/MHz.

As the sophistication of sensors continues to evolve the need for floating point calculations will grow to handle increasing levels of precision. Adding a floating point coprocessor is out of the question in sensors because of the extreme power and size limitations. While floating point calculations can be done on a 32-bit processor the performance will not be enough for many applications. Recognizing this Synopsys recently released a floating point unit that can be integrated with the EM processor cores. This floating point option (starting at 10K gates) requires only about 10% of the area and power of a coprocessor, but offers high performance for single and double precision math and complies with the IEEE-754 standard.

Because of the capabilities that they bring, sensor usage is growing geometrically and they are starting to show up everywhere and in everything. You interact with many more sensors every day than you do people. This is happening because of the new generation of 32-bit processors that are making devices possible that we could only dream about a few years ago. Can you imagine what we will be able to do five years from now!