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Re: USB Host
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  ASIC's do not have to be massive, merely application specific.
If a 4bit uC can be 5c, then I'd imagine a ROM AVR (toy class)
could be 10c. (This is a $3.6M/yr hypothetical die customer).
  Atmel are one the of bigger suppliers of Serial EE, so they
are well used to fab/test of very low cost silicon.


Re: USB Host
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And if you don't ask for a quote, you will never find out,
The AVR is maybe 1/10 of a square mm in the 0,13u technology.

Best Regards

Re: USB Host

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Ulf, the problem here is one of reality vs. the ideal.  The design is going
to reuse a significant body of code that I wrote for the 8051 over several
months.  It's an evolutionary step from an existing product.

And so, throwing out the 8051 makes no economic sense at this point.  If I
did that, I would simply implement Embedded Linux using one of the two
PowerPC processors available in the Virtex2 Pro FPGA on the board.  This
would get me all the I/O interfaces (including USB Host) that I want.
However, as it is sometimes the case, there's no time to dive into that one.
Maybe for the next revision?  :-)

If I simple path for USB Host on a fast (Slicon Labs) 8051 is not available
I'll just make provisions for migrating to Embedded Linux with a firmware
update and handle it that way.  The Philips chips might be an interesting
option.  I'll have have a look.

As Mark Twain said:
A man holding a cat by the tail learns something he can learn no other way.


Re: USB Host
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I did not say throw out the C51, I said add an AVR.

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Then the best solution for the AT43USB380 is to run the AT43USB380 library
on one of the PowerPCs. You can run it bare, without an OS.
You need to have memory for the PowerPC of course, and
this should be less expensive than the AVR for this solution to make sense.

You also need to compare the cost of adding a CPU with a free library
to the cost of buying a license for code.
Some companies will charge a lo for the USB sack, some will not.
Donšt klnwo about Philips, but some others will charge an ARM and a leg for
the code.

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Re: USB Host

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That's a good idea.  I'll look into that.  Shouldn't be too complex.  The
8051 could have access to data placed in a buffer by the PowerPC (talk about
upside-down and backwards!).  If I connect the peripherals to the FPGA, I
can, later on, simply not stuff the board with the 8051-related hardware and
migrate the firmware to fully implement the functionality on the PowerPC,
which is what I want.


Re: USB Host
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You need to contact your local Atmel FAE for more details.
There is quite a lot of info on the web, but you have to click go to tools &
software + register to get access

You need to have the same compiler as Atmel uses.

Best Regards
Ulf at atmel dot com
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Re: USB Host
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The least painful way would be to not do it at all, of course.  Second
least painful: have somebody else do it.  Implementing even a subset
of a USB host's job on an 8051 is definitely not something you want to
do yourself unless you absolutely, positively,
beyond-all-reasonable-doubt have to.  Just about *every* other option
will be less painful.

Hans-Bernhard Broeker (
Even if all the snow were burnt, ashes would remain.

Re: USB Host

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A USB Host for one device is not so bad.  The difficulty lies in what
you can't see or what is not published.  The easiest approach is to
Buy/Rent/Borrow a USB data analyzer and capture the enumeration
sequence for the targeted device.  Then use a Host controller like the
Cypress 811HS and a 8051 of your choice to enumberat the device
yourself.  After that, it is online and ready for communication.  We
have done this with several USB devices.

Re: USB Host
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That's exactly what I was thinking about today while reading through the USB
specs!  We control what device/s will connect to this box.  I reasoned that
it couldn't be that hard to figure out how to make the connection happen and
then, once the pipes are established, it should be just bunches-o-data
moving back and forth (and not that much of it).  We basicly need to
interface with an instrument that only has USB I/O...very low data volume
to.  A few measurements per second.  A handful of bytes per measurement.

Any suitable analyzers you might recommend?

I know that this wouln't be real USB "plug in whatever" interface.  The
point is, it doesn't have to be and it will never be.  The worst that can
happen is that a newer, better version of the test instrument is released.
It shouldn't be a big deal to issue a patch for that.


Re: USB Host
Cypress seems to have a couple of good solutions, as well as eval boards
with 8051-based Host mode firmware examples.


Re: USB Host
Sorry for the multiple posts.

Cypress most definetly has the answer.  Their links are horribly long and
complex, so I won't post one here.  Just search for CY3662.  Code,
schematics, PDF's and Powerpoint presentations for embedded host mode using
an 8051.

Code requirements for stripped-down, dedicated-device support (i.e. You know
what is likely to attach to your host port): 350 bytes!!!

All of a sudden the nightmare scenarios are gone.  This ain't bad at all.

Thanks for the very useful posts on this topic.


Re: USB Host

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Agreed.  A company should not be spending money on training staff
to do a task that is not at least somewhat central to their business.

There are exceptions, of course.  As an example -

 A medical device firm finds they do a lot of USB interfacing. They
 hire a _qualified_ consultant to do the job with one of their staff
 (Sr./Jr. makes no difference) as apprentice/trainee on the subject
 of USB so they have someone on call with an understanding of the subject.

I'm in the racket of being the one of those 'out of town experts'
who comes in and does 'something', so take that bias into account.
I find I end up doing quite a bit of mentoring.

Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer:  Electronics; Informatics; Photonics.
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Re: USB Host
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I couldn't agree more.  I wish I didn't have to do it.  Hence the Mark Twain
quote.  One of the challenges in Engineering is to make something with what
you have, not what you wish you had.  Even if it is not ideal.  Hell, anyone
can do it under ideal conditions!  Of course, if impossible you have to know
when to call it.  In this case, I think that there are a few interesting
possibilities of either full or
"highly-customized-crippled-but-usable-single-peripheral" implementations
with varying degrees of pain.


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