Embedded host with hub support

[rsm]

Subject line says it all: we need to implement an embedded USB host with hub support, and TPL limited to HID.  And just in case I'm not being clear, the host needs to be able to recognize and support a hub that is connected, not behave like a hub...

Our (current) hardware is PIC32, but the manufacturer has sort of left us hanging... ie., the part will support such a solution, but there is no sample code nor support available from them.

At this point, we don't really care about the hardware (willing to change if compelling reasons are found) - we're simply hoping for pointers as to where to find relevant literature.

Any info/advice much appreciated.

Thanks,
RSM

[Jan Axelson]

Thank you for posting your question to the forum.

The USB 2.0 spec spells out the duties of a host. On enumerating, the host has to detect the presence of a hub-class device, enumerate all downstream devices, and communicate with the hub's status-change interrupt endpoint. Also see the hub-specific control requests.

The OTG and embedded host spec says:

3.4.3
Hub class support
Since the hub class is defined in [USB2.0], hubs may be listed as a supported class on the TPL provided that all USB-IF certified hubs can be supported and that the Targeted Host can supply the 5 unit loads required by bus-powered hubs. If this is not the case then specific makes and models of hub must be listed on the TPL.

Some options for embedded hosts with built-in support for external hubs are the .NET Micro Framework modules from ghielectronics.com and the Vinculum (vinculum.com).

Jan

[HelenJames]

I think this topic was discussed loads of time before at this forum