[req] Need suggestions for a micro

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I have a client who is currently using a NEC V-25 at 16 MHz.
This micro is no longer adequate for several reasons:
(a) it's no longer manufactured, and (b) his expanded application
requirements need more computing power.

Can anyone suggest a replacement. Here's what we need:

* At least 20 address lines

* Can't be "PC-based", including PC-104. (ie it can't resemble
an x86 any closer than the V-25.)

* 16-bit preferred

* at least 33 MHz or better (66 MHz preferred)

* reasonably priced and well supported development tools.
(perhaps like AVRGCC for Atmel from avrfreaks.net)

Any help appreciated
Sean

Re: [req] Need suggestions for a micro

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Huh?  What kind of requirement is that?  Why would they rule out an
otherwise nice and applicable platform based on it being too PC-like a
design?  Is there any more rational point to this requirement than
"used that last time, hated it, don't want to see anything like it
soon"?

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As in: at least, at most, or exactly 16 bit?

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Given you haven't homed in on any particular architecture yet,
specifying MHz'es up front is quite silly.  Heck, even Intel finally
had to accept the fact that there's no such thing as "real GHz" ---
after having spent millions of dollars advertising there was.

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

Re: [req] Need suggestions for a micro

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The reason is that getting approvals and certifications for PC-based
equipment in my client's market is more difficult than for proprietary
boards.

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Agreed. These 2 items are purely for better performance.

Ideally we'd like a V-25 running 3 or 4 times as fast as currently,
if such a thing existed. Actually I've already recommended
an ARM-7 running at 66 MHz. However there's several drawbacks
to this; he needs a 5-volt part and ARM vendors seem to be moving
to 3V; also getting the ARM-7 GNU toolchain up and running seems
like quite an effort. My approach would be to get an eval board
with a fast micro, pull the V-25, RAM, EEPROM and EPROMs out of
his current board and try replacing it with the eval board
running a firmware port in flash.

Sean

Re: [req] Need suggestions for a micro
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  Not all ARM variants are moving to 3V, look at the new Motorola MAC71x1
family : this has on-chip regulators, and a comprehensive temperature
spec as well.
  How much code space do you need ? - the single chip ARMs uC come from
32K to 512K on chip FLASH
-jg


Re: [req] Need suggestions for a micro

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Thanks for the help, I'll check it out.

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Currently I'm using close to 100k bytes of code, but I also need
256k RAM.

Sean

Re: [req] Need suggestions for a micro

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MAC71x1

If you're going to address more than 65 kbytes of memory, you
should seriously think about using a 32 bit part, to facilitate the
unavoidable address arithmetic.

The ARM T variants (e.g. ARM7TDMI) are able to run 16 bit
(Thumb)  code for saving on code space.

The low-voltage core of the AT91 ARM consumes so little power
 that a simple linear regulator is more than sufficient.

Tauno Voipio
tauno voipio (at) iki fi






Re: [req] Need suggestions for a micro
On Wed, 21 Jul 2004 15:10:06 +1200, Jim Granville

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Are these Motorola ARMs actually available ? I found some datasheets
for them, but could not find anyone who lists them on their site. Can
anyone recommend a supplier from where one might be able to buy a
couple ?

Regards
   Anton Erasmus


Re: [req] Need suggestions for a micro

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I may be a bit dense today, but to me that sounds like you're saying
it's not your client itself who's gone nuts, but actually the entire
market they're working in?  It's one thing to say "Ordinary PCs won't
cut it in our market, because ...", but going out of your way to
effectively forbid anything that smells like a PC does seem excessive.

Someone call the "no discrimination" amendment (5th?) on the persons
ruling that market, please. ;->

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

Re: [req] Need suggestions for a micro
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Perhaps Sean can give us more information on what market area this is,
and if there is an historical basis for the aversion ?

Such an assertion did raise eyebrows, but it may have been something
that smells like a PC, could run something that smells like windoze ?
-jg



Re: [req] Need suggestions for a micro

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I can't say too much about it except that it's a specialty security
application and he tells me that any platform which could even
_potentially_ run any Microsoft o/s would instantly alienate
most of his customer base.

Sean

Re: [req] Need suggestions for a micro

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WinCE runs on a lot of platforms, including ARM, MIPS, SH, and, of
course, x86.

Regards,

                               -=Dave
--
Change is inevitable, progress is not.

Re: [req] Need suggestions for a micro

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I agree -- in fact I've suggested PC-104 several times.
However, the client insists on using his own proprietary boards
with a "proprietary operating system" (essentially a round-robin
task scheduler). I'm not involved with the approvals so I just
took his word for it.

Sean

Re: [req] Need suggestions for a micro
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I was able years ago to pursuade a client to use PC104 and
it has worked well for them.  But what is happening is that feature
creap in the available PC104 CPU from the vendor
(Megatel) has kept the price climbing as the mfg. drops the
older/simpler boards for more MHz and MB.  Result is I keep having
to defend that decision (for free), but I'm always looking for
cheaper alternatives. - RM


Re: [req] Need suggestions for a micro
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It's not just ARM vendors. The entire universe is migrating to lower
core voltages. Many ARM parts have 5V-tolerant I/Os, can you consider
that as an option? You can supply the core and I/O ring voltages (1.8V
and 3.3V typically) with small linear regulators; the currents
involved are miniscule.

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Not really, at least - not any more. <http://www.gnuarm.org/ is an
excellent resource.

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Should be able to do this with an ARM part that has 5V I/Os...

Re: [req] Need suggestions for a micro

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That's a very odd requirement.  May I ask why it can't resemble
an x86?

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So you don't want to look at cheap 32-bit parts?

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Well, specifying MHz is rather meaningless unless you're also
specifying a CPU architecture.

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I would recommend that you a look at the Renesas (nee Hitachi)
H8 series.  The low-end 32-bit ones (H8/300H "value" series)
start at $4 for a 25MHz part with 128KB flash and 4KB RAM.
IIRC, the newest "SX" version of the core runs at 50MHz.

Development tools are free: Gnu gcc and binutils.

You should also take a look at some of the low-end ARM based
uControllers.

--
Grant Edwards                   grante             Yow!  I want another
                                  at               RE-WRITE on my CEASAR
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Re: [req] Need suggestions for a micro
Sean,

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Yes, I can suggest a replacement: a 683xx or Coldfire processor.  It has a
clean architecture,
no messy segmentation to deal with, and a plentiful supply of tool vendors:
SDS in Illinois,
HI-TECH,ourselves and others whose names I can't bring to mind at present.
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The registers are 32 bit but you can use them 16bit-wise; use the ".w"
specifier
on instructions.
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I think it can meet that.
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That really depends on whether you mean supported or maintained.  If you
want decent support, a vendor is going to have to charge at the very minimum
$500
to be able to afford this without charging extra.  If you mean "currently
maintained", that is a different question.

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If you want to go for GCC tools, you'll have to frequent GCC user groups to
get help.

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Not at all,

Dave Bardon, Avocet

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Re: [req] Need suggestions for a micro
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If you're interested in another x86, I've had no
problems with the RDC R8822.  We've got 2 boards
based on the design, one of which replaces our
V-25 board.  The R8822 is a pin-compatible replacement
for the AMD 186ED.  It runs at 40mhz and will
interface directly with cheap DRAM.







Re: [req] Need suggestions for a micro

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For a non-x86 processor, my vote to an ARM, e.g. Atmel AT91 -series.

The question of MHz is here somewhat moot, a x86 uses the clocks
very differently compared to real RISC processors (like ARM).

There are full GNU toolsets (GCC, assembler, linker, debugger and
utilities) for ARM running on different host systems.

Tauno Voipio
tauno voipio (at)  iki fi




Re: [req] Need suggestions for a micro
Have a look at the Toshiba TLCS-900, this is heaven to
write code for, its what a Z80 would be if it was 32 bits.

remember LD  A,(HL), well now its LD A,(XHL+)

where XHL is 32 bit reg with auto-incr......


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Re: [req] Need suggestions for a micro
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If it's going to be a new design, you might try a
core module instead of designing from scratch.

http://www.rabbitsemiconductor.com/products/rcm3300 /

http://www.rabbitsemiconductor.com

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