In case you haven't noticed, the distinction between DSPs and micros is blurring, as each side loots the other’s quiver of architecture and tool tricks. In fact, as far as I'm concerned, the difference is more a matter of marketing than technology at this point. Processors, whatever they're called, will increasingly be called on to handle both 1s-and-0s as well as all types of signals.

In fact, I had to laugh when I got my first glimpse of the new Motorola 56311 DSP, pictured in Figure 2. Notice the little block near the top center called the Enhanced Filtering Coprocessor. It's a 24-bit filtering and echo-cancellation coprocessor that runs parallel to the DSP core. Basically, we're talking a DSP with a DSP coprocessor, highlighting the futility of trying to figure out what's a DSP and what isn't.