A DSP in Every Pot?

Not that long ago, digital signal processing was the province of a handful of specialists. The complex mathematics coupled with a speed-driven demand for computational efficiency made programming DSPs a major challenge. Added to that was a lack of high-level programming tools targeted for DSP's unique needs. It was the age of the DSP guru.

That situation is changing. Digital signal processing is now the standard means of handling communications signaling. The modem, for example, has gone from a custom mixed-signal device to a pre-programmed DSP. Cellular telephones all have DSPs handling signal conditioning these days, even the analog units. Even radios, with their tuned circuits, analog mixers, and intermediate frequency amplifiers, are going DSP. Software-based radios are moving from being the exception to being the norm.

Another indication of the change can be seen in the addition of DSP functions to conventional microprocessors. The PowerPC started the trend by incorporating AltiVec technology for vector processing. The Tensilica core announced last year allows some DSP functions to be blended in as you design your custom processor. More recently, the ARC 3 core came out with in-core DSP capability.

There are good reasons why such blended processors are coming out. The DSP runs rings around the conventional processor when it comes to high-precision calculations. The trouble is that the very structures that make it fast at math, including pipelines and parallel execution elements, are a serious impediment when it comes to control operations. In control applications, flexibility is the key to rapid program execution. Pipelines don't flex very well.

Many of the high-volume applications of DSP, especially cellular phones, use both a DSP and a conventional processor. Some custom devices now offer both processor cores on a single chip. Thus, it was only a matter of time before the two were blended, and these first entries are seeing considerable interest in the markets.

It's not too far-fetched, then to speculate that DSP functionality will spread even farther, perhaps into virtually every high-end processor. Embedded applications must work in an analog world, and DSPs are a powerful way of handling the analog world's continuous functions, at least to a good approximation.

Increasing processor and DSP capabilities will see the applications for DSP proliferate as users demand ever more friendly interfaces. Voice synthesis and voice recognition will become standard features of consumer devices. Image understanding algorithms will allow systems to process visual information. Then, too, image and graphics processing devices will allow systems to display richly complex images to users.

Yes, it is beginning to sound more and more like science fiction. It's not, though. Digital signal processing is coming out of the ivory tower and hitting the streets. It may not enter every application space, but it will enter many. The time to prepare is now. When there's a DSP in every pot, you had better know how to cook with them.