Tech Support > Computer Hardware > Microprocessors > Rabbit micros - any good ?
Rabbit micros - any good ?
Posted by Colin MacDougall on March 2nd, 2004


Hi,

I was thinking of buying a Rabbit Semiconductor evaluation
kit for either the Rabbit 2000 or 3000 range. Has anyone
here had any experience using these micros, and any comments
good, bad or indifferent. The large amount of serial ports
looks quite good and the instruction set doesn't look too
far removed from the Z80. This is not an attempt to canvas
the usual 'micro x is better than micro y' - just interested in
seeing if anyone uses these devices, and what they think and
is the supplied C compiler 'Dynamic C' any use ?

Thanks,

Colin


Posted by Richard on March 3rd, 2004


Colin MacDougall wrote:
May I suggest:
http://groups.google.com/groups?q=Ra...rch.embedded.*
or
http://groups.google.com/groups?q=Dy...rch.embedded.*

It's a topic that comes up here regularly. In short... nice product;
great value; you will get up & running quickly. It nicely fills the gap
for serious hobby-grade stuff short-run production volumes, for a lot
less than you could do your own low-volume run.

Dynamic C is not ANSI-compliant, so don't be surprised when stuff needs
effort to port - this gets a lot of people worked up. If ANSI is
important, you can buy a 3rd-party ANSI compiler.

There's a Yahoo discussion group you should check out. That'll give you
a good feel for the issues real-world users are encountering.

Posted by Ian McBride on March 3rd, 2004


As you surmise, the Rabbit is a Z80 with an embedded Ethernet controller and
a lot of serial ports. It also comes with a fairly complete development
kit, including "out-of-the-box" networking which is perhaps its biggest
advantage.

The only weakness in my opinion is the Z80. This was a new chip when I was
in high school, and it's a tough case for high-level language support.
Other possible network chip alternatives are the Motorola Coldfire CF5282
and the accompanying NetBurner development kit, and the various ARM
offerings from NetSilicon. Both of these come up fast, and they have a
processor core with some real umph.

But if what you need is a quick solution for network connectivity, and you
don't have a requirement for a fast CPU, Rabbit is a good choice. Everyone
I know who has used one has been very positive.



Posted by Kelly Hall on March 3rd, 2004



"Ian McBride" <ianmcbride2003@yahoo.com> wrote in message
news:Tvb1c.30890$hm4.12054@newsread3.news.atl.eart hlink.net...
The Rabbit is more of a Z180 derivative than a Z80 derivative, and the
current models (R2000 and R3000) do not have a builtin Ethernet MAC -
they use external 8-bit Ethernet controller chips. The CPU does have a
bunch of serial channels onboard, but no FIFOs so serial performance is
somewhat less that you might expect. The Rabbit hardware is pretty
nifty, although the Dynamic C software has traditionally been less
pleasant to deal with. Lots of available libraries, and an active
discussion forum make this product pretty well supported.

Don't plan on using ANSI C external libraries on the Rabbit without
spending time (for Dynamic C) or money (for Softools C).

Kelly


Posted by Dave Moore on March 3rd, 2004



"Colin MacDougall" <colin |D0T| macdougall@btinternet.com> wrote in message
news:3d71c.1079$Db4.399@news-binary.blueyonder.co.uk...
Ya, I've used the Rabbit stuff (both 2000 and 3000 series models.) The
google group is solid for technical help.

- I started with the 2000 and went up to the 3000 when I needed more serial
ports. I've got ethernet, 6 serial ports running, some external 8bit i/o,
ppp running via sync serial at 56kbps.
- The DC environment is a bit difficult sometimes. Takes some getting used
to regarding library inclusion and "include" files. They aren't standard
stuff as has been mentioned here.
- Tech support from zworld was sketchy. They've been working on it, and
it's getting better.
- They've recently started charging money for "add ons" like SNMP and PPP.
It was free with the premier package prior to 8.x, now it's additional
dollars. Not a lot mind you, but some.
- Dealing with xmem is a bit tedious. There is only a small amount of root
code and data space, and you have to do some funky stuff to use the rest of
the address space. There is another toolchain offering from softools that
helps that problem a great deal.
- For getting to market quick, it's a winner.

Good luck.

-- Dave



Posted by CBFalconer on March 3rd, 2004


Ian McBride wrote:
Also don't plan on reusing any Z80 or Z180 code. The Rabbit is
NOT binary compatible, so you can't use generic CP/M software.

--
Chuck F (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!



Posted by Richard on March 3rd, 2004


The Rabbit development kits are really good value for money - you can get a
system up and working in no time at all. But without wanting to sound
contradictory, you get what you pay for - if you don't spend much you cannot
expect miracles.

Big things in its favour - networking capability + get up and running
quickly.

Big things not in its favour - Dynamic C. Parts of it look like C, granted.
The IDE is particularly difficult if your project contains more than one
source file. A "project" is not what you might expect it to be.

Expect to spend time learning the peculiarities of the environment in
addition to the time normally spent learning a new processor.

Have a look at http://www.FreeRTOS.org/PC for a comparison of the Rabbit
performance with other low end processors.

Richard.




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