email@example.com (Julia Goolia) wrote in message
Since many of the posts haven't responded directly on the Rabbit's
abilities, I'll toss in my (longish) $0.02:
Others' comments on HLL support (e.g. C compilers, FORTH) are quite
The Rabbit *does* have a hardware multiplier, and some other opcodes
(find leading 1 in word, I think) that speed up math considerably.
Some benchmarks are posted at
Of course, benchmarks can be manipulated, and I don't know exactly how
they ran them. They post the code + some details at the
above-mentioned site, which I take as a good sign.
There is a C compiler for the Rabbit 2000/3000. (Actually 2, one from
zworld/rabbit semi, the other from http://www.softools.com/ -- which
claims to be ANSI compliance.)
A good resource is yahoo newsgroup rabbit-semi:
Zworld's compiler "Dynamic C" (aka DC) isn't ANSI C, but it's
(IMHO) usable, albeit imperfect (the error messages are often
unhelpful, to put it kindly.) The default int size in DC is 16 bits,
but long int is 32. The rabbit C compiler also has respectable (for
an *8* bit cpu) single-precision floating point, see benchmark site
above. Rabbit CPUs have a 16 bit logical/20 bit physical address
setup (similar to the Z180) Most data +interrupt code can only be in
the first 64K, but this is still bigger than the PICs I've looked at
(am I out of date on PICs?)
Another poiint in the rabbit's favor are the many *SOURCE CODE*
libraries and examples that come with DC. The on-chip peripherals
(RTclock, counters, serial ports, etc.) are fairly-well supported in
the libraries and examples. A TCP/IP stack comes with starter kits
that include Ethernet (not part of the lowest cost kit, sadly.) The
3000 has encoder interfaces and PWM, which are handy for motor
control. IMHO, the rabbit boards (and the starter kits) are pretty
good bang/$ (though more than entry-level PIC kits, from what I've
seen.) Depends on your budget, and what level of performance and
expandability you want.
IMHO, a Zworld starter kit like the jackrabbit, may well be worth the
extra $ because of the software and the expandability (compared to a
PIC.) There are many other choices. So I'd listen to what others say
about the AVR, TI (430?) etc. But think hard about your software: do
you want to code strictly in assembly, or would you rather have
C/FORTH/pick-another-HLL available where utmost speed isn't required?
I value my time and my hair, so I want the option of a HLL. (Plz
don't start another flame-war about the merits/demerits of FORTH, or
whether it's an HLL. It's *useful* in resource-limited apps.)
Having said all this, there are some 32-bit alternatives, that I'm
pondering for heavier comptational lifting. E.g. the ARM7-based
offerings from Atmel and Philips (LPC2000)
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.