OPENCORES.ORG

Everything mentioned in your mail seems fine other than the 500 ms pause.

Steve
18 bytes as device descriptor,
0x12,                                           // bLength
0x01,                                           // Device Descr
0x00,                                           // bcdUSB(lo)
0x02,                                           // bcdUSB(hi)
0x00,                                           // bDeviceClass
0x00,                                           // bDeviceSubClass
0x00,                                           // bDeviceProtocol
0x40,                                           // bMaxPacketSize0
0x3f,                                           // idVendor(lo)
0x05,                                           // idVendor(hi)
0x55,                                           // idProduct(lo)
0x00,                                           // idProduct(hi)
0x00,                                           // bcdDevice(lo)
0x01,                                           // bcdDevice(hi)
0x01,                                           // iManufacturer
0x02,                                           // iProduct
0x03,                                           // iSerialNumber
0x01                                            // bNumConfigurations

regards

Steve wrote:

> Everything mentioned in your mail seems fine other than the 500 ms pause.
>
> The host first requests the device descriptor, it requires at least 8 bytes.
> You can send 18 but all the host is after is the control endpoint size held
> within the first 8 bytes.
>
> It might be best now if you post the 18 bytes of information that you return
> as im sure this is why the host is waiting so long.
>
> Thanks
> Steve
>
> Sponsor me online for the Flora London Marathon
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>
> > -----Original Message-----
> > From: usb-bounces@o... [mailto:usb-bounces@o...]On
> > Behalf Of P.Ravi
> > Sent: 25 February 2004 07:37
> > To: usb@o...
> > Subject: [usb] Enumeration
> >
> >
> > Hi
> >
> >   Is there any difference if we send 18 bytes of data instead of 8 bytes
> > when host requests for device
> >   descriptors after reset.
> >
> >   Can anybody explain what exactly is happening here
> >
> >   host - > reset
> >   host  -> request for device descriptors
> >   device  -> responding with 18 bytes of device descriptor
> >   host -> reset
> >   device -> set address to 4
> >   host -> reset
> >
> >  Please note that acks are present but not mentioned. There is no nack
> > either from device or host.
> >
> > Instead of another request form host for device descriptors its issuing
> > reset.
> >
> >  After set_address there is 549.673 ms silence and then host is sending
> > reset.
> >
> > Please help
> >
> > Thanks in advance.
> >
> > regards
> >
> >
> >
> >
> > _______________________________________________
> > http://www.opencores.org/mailman/listinfo/usb
>
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