LPC1837_Xpresso board: does the USB0 host interface support more than one device?

[lpcware]

Content originally posted in LPCWare by waltwallach on Mon Mar 10 23:15:43 MST 2014
Reading in Host.h, there is a comment associated with USB_HOST_ADDRESS:

/** Indicates the fixed USB device address which any attached device is enumerated to when in
*  host mode. As only one USB device may be attached to the LPC in host mode at any one time
*  and that the address used is not important (other than the fact that it is non-zero), a
*  fixed value is specified by the library.
*/
#define USB_HOST_DEVICEADDRESS                 1

Does this mean that only one device may be connected to the port (i.e., does this mean I cannot connect a hub to this port, and address devices through the hub)?

There are many items that are global static values which I would expect to be per-device, and the operations in HostStandardReq.h are oriented towards "the attached device" and not a specific device.

If so, then what does USB_Host_SetDeviceAddress (in HostStandardReq.h) do?

Is this a restriction of the LPCUSBLib?

Thanks

Walt

[lpcware]

Content originally posted in LPCWare by drs on Fri Apr 11 16:57:38 MST 2014
Yes there is only one port on each of the two USB controllers on this part, and yes only one device can be connected to the port.
The device you connect to the port can be a hub but we do not have hub support in our USB host stack at this time.
If you look around in this forum you will find some folks who are writing their own hub support on this other parts in this family. Perhaps you can contact them to see if they are willing to share their experience.
Right now we have no plans to produce a hub driver for our host stack, but this could change if we begin to see significant demand for this.