[sdiy] Need general advice for a uP

[Theo]

Personally I prefer the AVR too.
I've done assembler coding, the large number of working registers (32!) on
the AVR makes this a happy exercise :)
The PIC on the other hand gives only 2 working registers and the memory
structure forces you to do a lot of bank switching, bad :(
When it comes to speed the fastest PIC parts have the advantage, however a
AVR on the same clock speed is faster.
PIC code size is larger and the pipe line does not fire things up to 1
instruction/cycle (cause of the frequent jumps?).

Some other uC worth a look are:
Senix (now ubicom) SX series, beware: high clock speeds, but soft
peripherals eat your cycles.
http://www.ubicom.com/

PSoC parts from Cypress: CY8C25xxx/26xxx
http://www.cypressmicro.com/
Disclaimer : Never tried them, but...
Like the SX the peripherals are user configurable, however they are
hardware.
The interesting thing is that the PSoCs have an analogue twist :)
At least worth a look!

Theo



From: Jim Patchell <patchell at silcom.com>

>     Ah yes...good old 6502....
>
>     There are only two viable picks for 8 bit micros...the PIC and the
AVR.
> Both are good choices.  I personally, prefer the AVR, most ly based on the
> instruction set.  It looks the most comfortable from a user perspective
(to me
> at least).  So far, I have only programmed the AVR in "C", and I am very
> pleased with the results so far.  Now, the one thing I do not like about
> microcontrollers is the fact you can't stick a scope in there to see what
is
> going on, but, that is life.  Having everything contained on a single chip
is
> great.
>
>     One of the great things about the PICs is you have a HUGE selection of
> parts.  The AVR seems to have better "C" compilers.  There are trade offs
> apleanty in choosing the device you are going to go with.
>
>     If you haven't visited http://www.dontronics.com , do so, he sells
stuff
> for both processors.
>
>     -Jim
>
> Glen wrote:
>
> > Once upon a time, I had a small amount of experience with breadboarding
and
> > programming a "6800" based SBC. It was so primitive, it was actually
> > programmed in machine language, as opposed to assembly language. I also
had
> > a little experience programming a 6502 based system in assembly language
> > and in BASIC. This was all in the early to mid eighties, and I haven't
done
> > any DIY computer hardware work since then. I know, a *lot* has changed
> > since then.  :)
> >
> > I currently have the desire to play with some simple uP designs, but I'm
> > not sure which devices would be the best for the types of things I'd
like
> > to do. I'd like to eventually build some things like MIDI -> CV
convertors,
> > a custom Poly-Synth, MIDI "knob boxes", and similar musical devices that
> > need some sort of brain inside them.
> >
> > Does anyone have any suggestions for a "hobbyist friendly" uP? I need
> > something fairly simple to implement, easy to find and purchase in
> > single-unit quantities, inexpensive, etc. Also, I need something in a
> > through-hole package, instead of surface mount. Also, should I be
looking
> > at PIC's?
> >
> > Are EPROMS totally out of style now? Is there something easier to
program,
> > which doesn't need an expensive device programmer?
> >
> > I know these all sound like very beginner-level questions. I've actually
> > spent several years repairing musical devices that employ uP's, but
that's
> > totally different from actually designing such circuitry. I'd appreciate
> > some pointers to start me off in the right direction.
> >
> > thanks,
> > Glen
>