lpcware

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

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by 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

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