lpcware

Cannot communicate to LS device through FS HUB.

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by sycc90 on Mon Feb 15 21:17:12 MST 2016
Hello everyone!

I'm developing an application with the LPC4337 uC using the embedded USB HS hardware and the LPCOpen USB library.
I need to communicate with a LS device that's connected downstream from the uC through a FS HUB, unfortunately this does not seem to work. After requesting for a control transfer (with the interface provided by LPCOpen: HcdControlTransfer) it gets stuck waiting for it to finish (by querying the transfer status). If I replace the FS HUB with a HS one then it works perfectly, so that somehow makes me think there's some trouble when dealing the a LS transaction through a FS HUB.
According to the manual (UM10503: section 25.8.1.4), the uC should handle sending the appropiate FS PRE-PID followed by the LS transfer and whatnot. So I'm certain this is supposed to be supported.

Is there anything I can try? It doesn't seem as if there's anything I need to configure (besides the pipe's speed, which I've set to LS as indicated by the manual section I indicated above, is that right?), it appears it's all handled internally by the LPCOpen library, so I'm kind of at a loss as to what to try.
I'll see if I can get a FS device to connect downstream and try that with the FS HUB to see what happens... in the meantime, any ideas?

Thank you all for your help!!

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