will this work? Special USB Mux

[tgrandahl]

usbmux

I have 6 usb devices and 10 host ports, i need to confirm that every possible connection configuration will work. There are more than 151,200 possible configurations... Yes this sounds silly, unfortunately it needs to be done.

I have found maxim 1:8 USB mux's available, however would like to avoid building a custom board for them if possible. I would also rather invest the money in a CPLD board that could be re-used for later projects.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P0305-ND

All the USB mux's i have found look to be completely passive to the data lines as they list an on state resistance.

Unfortunately using a CPLD I am pretty sure that the switching would need to be more active. Because USB is half-duplex the device will need to interpret when data is flowing upstream and down.

What would be the best course of action to take and what kind of hardware would be needed external to the CPLD to interface with the usb signals? I dont suppose i can simply attach D+ to GPIO pins...

Any help would be greatly appreciated.

Thanks

 

[20pilot]

If you are planning to do this under Windows, you may have a bigger problem with the OS. Depending upon what the devices are, if you do not disconnect them cleanly, Windows may get unstable.