Embedded USB

I'd like to interface a USB mouse to an FPGA. Does anyone have any advice 
regarding how best to go about doing this. I suspect the use of some form of 
bridge chip or uC is the way to go but all these seem dominated by the 
assumption that a PC is involved. Has anyone had any experience in doing 
this kind of thing please?

TIA,

Rog. 

Roger wrote:
> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice
> regarding how best to go about doing this. I suspect the use of some form of

There are UHCI and presumably EHCI cores for FPGAs. However, it's a
*lot* of space in your FPGA, just to support a mouse. Maybe you want to
consider one of the embedded host ICs like the Cypress SL811HS.

Roger wrote:
> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice
> regarding how best to go about doing this. I suspect the use of some form of
> bridge chip or uC is the way to go but all these seem dominated by the
> assumption that a PC is involved. Has anyone had any experience in doing
> this kind of thing please?

Go to your local hamfest/computer swap meet and see if you can find
someone who will trade your USB mouse for a serial or PS/2 one.

The difference in complexity of the project will be reduced by a factor
of several hundred...

cs_posting@hotmail.com wrote:

>Roger wrote:
>> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice
>> regarding how best to go about doing this. I suspect the use of some form of
>> bridge chip or uC is the way to go but all these seem dominated by the
>> assumption that a PC is involved. Has anyone had any experience in doing
>> this kind of thing please?
>
>Go to your local hamfest/computer swap meet and see if you can find
>someone who will trade your USB mouse for a serial or PS/2 one.
>
>The difference in complexity of the project will be reduced by a factor
>of several hundred...

...unless your anticipated build volume exceeds one.


-- 
========================================================================
          Michael Kesti            |  "And like, one and one don't make
                                   |   two, one and one make one."
    mrkesti at hotmail dot com     |          - The Who, Bargain

Roger wrote:
> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice
> regarding how best to go about doing this. I suspect the use of some form of
> bridge chip or uC is the way to go but all these seem dominated by the
> assumption that a PC is involved. Has anyone had any experience in doing
> this kind of thing please?
>
> TIA,
>
> Rog.

Hi,
You may be able to use a VNC1L from FTDI (USB host controller).
See http://www.ftdichip.com/FTProducts.htm#Vinculum

- Charles

Roger wrote:
> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice 
> regarding how best to go about doing this. I suspect the use of some form of 
> bridge chip or uC is the way to go but all these seem dominated by the 
> assumption that a PC is involved. Has anyone had any experience in doing 
> this kind of thing please?
> 
> TIA,
> 
> Rog. 
> 
> 
  Atmel AT90USB1287 is a uC with onboard On-The-Go USB controller. OTG's 
can be both host and device...

/RaceMouse

> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice 
> regarding how best to go about doing this. I suspect the use of some form of 
> bridge chip or uC is the way to go but all these seem dominated by the 
> assumption that a PC is involved. Has anyone had any experience in doing 
> this kind of thing please?

You could try using the Maxim 3421E which is driven through an SPI 
interface.  I've used one of these and they are quite straightforward to 
program (a simple register interface).  As others have remarked the FTDI 
and Cypress chips are alternative possibilities.

	Andrew

Roger wrote:
> I'd like to interface a USB mouse to an FPGA. Does anyone have any advice 
> regarding how best to go about doing this. 

My advice would be: don't try.  It may be possible, but it's almost 
certainly not practical.

Unless that FPGA is really very big, and doing a heck of a lot of things 
already, the USB implementation would probably end up an order of 
magnitude bigger than the entire rest of the the project.   It takes a 
rather powerful CPU and a good deal of extra code/builtin libraries to 
implement USB host-side.  Doing that in an FPGA would be like mounting 
your bed-side alarm-clock on an 18-wheeler in order to move it long 
distances.

 > I suspect the use of some form of
> bridge chip or uC is the way to go but all these seem dominated by the 
> assumption that a PC is involved. 

That's because the whole *idea* of USB is that a PC should be involved. 
      The move towards USB can be interpreted as a nifty marketing plan 
to keep PCs alive and present in households for the foreseeable future.

On Sun, 21 Jan 2007 22:31:40 -0000, "Roger"
<enquiries@rwconcepts.co.uk> wrote:

>I'd like to interface a USB mouse to an FPGA. Does anyone have any advice 
>regarding how best to go about doing this. I suspect the use of some form of 
>bridge chip or uC is the way to go but all these seem dominated by the 
>assumption that a PC is involved. Has anyone had any experience in doing 
>this kind of thing please?


I do not know how complex (in matters of FPGA cells) a USB host is,
but I think it could be easily placed into one.

I guess you have some kind of soft-core on the FPGA, so you might pull
lot of the protocol into software. Also limiting it to USB mouse only
might simplify the design.

Anyway, an (fullblown) USB host stack takes about 8K Code on an
ColdFire.

-- 
42Bastian
Do not email to bastian42@yahoo.com, it's a spam-only account :-)
Use <same-name>@monlynx.de instead !

On Thu, 25 Jan 2007 00:34:45 +0100,
=?ISO-8859-1?Q?Hans-Bernhard_Br=F6ker?= <HBBroeker@t-online.de> wrote:

>Unless that FPGA is really very big, and doing a heck of a lot of things 
>already, the USB implementation would probably end up an order of 
>magnitude bigger than the entire rest of the the project.   It takes a 
>rather powerful CPU and a good deal of extra code/builtin libraries to 

Nope. A 180MHz ColdFire can do, and I guess lower speeds would as
well.


-- 
42Bastian
Do not email to bastian42@yahoo.com, it's a spam-only account :-)
Use <same-name>@monlynx.de instead !