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Re: Minimal uC's with CAN? (still a hardware newbie)

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Of course.  Several classes of such, in fact.  You'll want to check
out the web site of Can-in-Automation (www.can-cia.de) for lots of
pointers.

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The difference is that between a working and a non-existent CAN bus.
CAN *requires* transceivers for proper operation.  The only question
is whether they come as separate chips or integrated into the CAN
controller.  Likewise, the CAN controller can be integrated with some
micro, or be a standalone device.  So you can have anywhere between
one and three chips to handle a CAN connection.


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

Re: Minimal uC's with CAN? (still a hardware newbie)
aachen.de says...
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Do you have any pointers to devices with integrated tranceivers?  I'd
like to see them.

Robert

Re: Minimal uC's with CAN? (still a hardware newbie)

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I spent quite a bit of time the past couple months looking at mid-range (16
bit) uC's with CAN controllers, and I never found any with integrated
transceivers.  Perhaps there are some low-end or high-end parts I missed
that had transceivers, but based on my limited knowledge of the economics of
mixed-mode ICs I'd be surprised.

--
Grant Edwards                   grante             Yow!  Where's th' DAFFY
                                  at               DUCK EXHIBIT??
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Re: Minimal uC's with CAN? (still a hardware newbie)

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Care to share what you DID find?

I'm particularly interested in the 16-bit uC range...


Fredderic

Re: Minimal uC's with CAN? (still a hardware newbie)
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ST                 ST10Fxxx
Infineon           C16x, C26x, XC16x
Mitsubishi         MC16/6Nxxx
Hitachi            H8S/26xx
Fujitsu            MB90Fxxx
National           CR16xxxx
Motorola           68HC912xxxx
Intel              80C96 (??)

Prices generally run in the 10-15 USD range for parts with CAN and 128K-256K
of flash.  If you want to include ARM7T in the "16-bit" camp, then there may
be some OKI parts with CAN -- I don't remember.

The C166 architecture seems widely used and tool support is pretty good. H8
also seems popular and there's plenty of info and support available. M16C
support isn't as good: technical information on some features of the part
was impossible to obtain. Tool support wasn't as good, and Mitsubishi's
documentation is lacking.

The Motorola part is a joke: it's the same tired old 6811 architecture with
built-in bank-switching so they can claim to support 128K of internal flash.
Bank switching was an evil, time-wasting hack 20 years ago, and it still is
today.  I can't believe Mo has integrated it into a die.

Fujitsu and National seemed poorly supported by both commercial and free
tools.

Intel's parts seem to be at end-of-life, and I didn't like the '96
architecture when I worked with it a many years back.

The cheapest 16-bit solution I've found is a Hitachi H8 "value series" part
at $4 plus an external CAN controller for $2.  That's compared with several
comparable parts with integrated CAN that come in at about $10. Another
advantage is that the external CAN controller has a much larger Rx FIFO and
is therefore better suited for the protocol I'm using than any of the
internal ones.

My main complaint about all of the parts listed above is the ROM/RAM ratio.
It seems to be fixed at about 32:1, and my applications always seem to need
something around 8:1.  I wondered if that was just a personal problem, but
recently a buddy of mine mentioned that he always ran into the same problem.

My other complaint is that all CAN parts (both external and integrated uCs)
seem to be 5V.  5V would be OK, except it looks like many other categories
of parts are going to start getting scarce in 5V, and I really want to avoid
a mixed 3.3/5v board.

--
Grant Edwards                   grante             Yow!  Where's th' DAFFY
                                  at               DUCK EXHIBIT??
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Re: Minimal uC's with CAN? (still a hardware newbie)

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the OKI ARM is ML67Q2003 http://www2.okisemi.com/us/docs/ARM9.html
and OKI has a stand alone CAN, based on the Bosch C_CAN IP working with
3.3V.

If you like the Texas Instruments DSPs TMS320LF24x be counted as 16 bit
controllers, add them to your list of micros with integrated CAN. They are
working with 3.3V too. And most importand, as far as I know TI is the only
one having transceivers working with 3.3V

On http://www.CAN-Wiki.info/ you can find a table with prices, maintained by
CAN users

Regards
  Heinz




Re: Minimal uC's with CAN? (still a hardware newbie)
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I found the data sheet for the stand-alone controller as well.
However, there was no trace of the part on OKI's North American
web site, and none of the distributers have heard of it. Either
it's vaporware or it's just not available over here yet.

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Yea, I forgot to mention the TI DSPs.

--
Grant Edwards                   grante             Yow!  After THIS, let's go
                                  at               to PHILADELPHIA and have
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Re: Minimal uC's with CAN? (still a hardware newbie)

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I didn't see any mention of this one...?


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Google is my friend...  ;)


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Thank you very much for that lot...


Fredderic

Re: Minimal uC's with CAN? (still a hardware newbie)
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Not really --- as I said: it can be done.  That doesn't automatically
imply anybody actually did it; or if they did, that they'll sell the
chips on the open market.

Design sanity says that you always should have the transceivers as
separate chips, so you can select whatever line characteristics you
need (high-speed, or fault-tolerant, opto-isolated or not).  OTOH,
some applications may want them integrated just to save yet another
couple of mm^2 on the PCB.

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

Re: Minimal uC's with CAN? (still a hardware newbie)
aachen.de says...
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Ah, sorry, I missunderstood you.  I thought you meant you knew of such
devices.

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That's where I thought matters sttod.  I can think of a few applications
I've been involved in that could have benefitted from a wholly integrated
solution but even for them that would have been secondary to cost (and
considering how inexpensive the tranceivers are... ).

Thanks for the clarification.
Robert

Re: Minimal uC's with CAN? (still a hardware newbie)
Look at the LIN standard.


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