PC controller.

[Stephen Dubovsky]

At 09:20 AM 10/2/96 -0500, you wrote:
...
>I have used a 68hc11 alot. Any thing you do at much speed at all has to be
...


Ok, I going to have to ask...  Has anyone out there thought of using a DSP?
Before you jump down my throat about cost and stuff Ill explain.  Analog
Devices high end fixed point DSP (the ADSP2181) is a full 16 bit machine w/
40 bit accumulator, runs 20-33MIPS sustained, can do single cycle
multiplies, has a 'C' like assembly language (by FAR the easiest Ive ever
seen to learn and read), and about 32kwords 0wait state of program and data
ram (more than enough for most projects and look up tables).  One of the
slickest architectures Ive seen for fast embedded control (we use its slower
cousin the ADSP2101 for alot of three phase motor control).  Oh yeah, the
cost issue.  Well you can get the EZ-KIT-LITE (a protoboard w/ ADC,DAC and
software) for <$100.  You can download software via a serial cable (or put
in an EPROM when its final) and play all you like.  The disadvantage is that
it doesn't have any parallel ports built in (things have to be memory
mapped) but it has provisions to add several wait states to talk to slow
ADCs and the like.  It does have 2 fast synchronous serial ports to attach
things to.  If anyone is interested, I can probably dig up more info, but
since you have email, you can probably go to the ADI website and get it
yourself... http://www.analog.com
  DSPs were sort of invented for this purpose.  In our apps we sample
several sensors, do some vector math, 2 or more PI loops, and some more
vector math in <20us (50Khz interrupt rate).  The things really do fly.  (In
more familiar terms, at 6000rpm you can execute >555 instructions for every
1 degree of crank rotation! is that quick enough? ;)

Hope it helps...
SMD
-does it sound like Im plugging ADI? (and no, I dont work for them;)