I have not used a DSP chip as of yet. All I know is that their architecture is such that they can carry out calculations quite fast, usually within a clock cycle, they have multiply-accumulate instructions in their instruction set and they have DMAs so the CPU does not have to waste precious time moving data around. I think there is more to it, but these are a few basic points.
I can see that Microchip has dsPIC which is their DSP chip line. Can't we just use a PIC18 or PIC32 which also has built in multipliers to do DSP as well? How is the dsPIC different from the normal PIC?
My main question is this, Why do we need to have something seperate and distinct called DSP chip and not integrate high precision floating point unit calculation capability on all the microcontrollers? Surely with the process technologies we have now, this should not take a lot of space.
Also, how do I know that I need to use a DSP chip in my project rather than a normal microcontroller>