Dear All, Any one can tell me a detail difference between full&low speed transceiver, or give a reference documnet about this, or point out which chapter in USB spec talk about this? If i have a full speed transceiver in host end, can i connect a mouse to host and work properly? Actually, I did it and found some work, but some failed. Thanks for your help! xianshic __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

hello Xianshic
well first off all there is no lowspeed transceiver, when u connect a low speed device, the host (root Hub) or the hub u are connecting the device to detects a lowspeed device and deals with it as a low speed.
I guess what happened with u concerning the mouse, I think this is a different issue, check the OS may be!
many more details are distributed in the specs. u should go through it hope that helps Abukhater xianshic xianshic@yahoo.com> wrote: Dear All, Any one can tell me a detail difference between full&low speed transceiver, or give a reference documnet about this, or point out which chapter in USB spec talk about this? If i have a full speed transceiver in host end, can i connect a mouse to host and work properly? Actually, I did it and found some work, but some failed. Thanks for your help! xianshic __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ http://www.opencores.org/mailman/listinfo/usb --------------------------------- Do you Yahoo!? Yahoo! Search presents - Jib Jab's 'Second Term' -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums/usb/attachments/20050126/af61c7ca/attachment-0001.htm

Thanks Abukhater.

for full-speed signaling are inverted from those for low-speed signaling. in Figure 7-14. Downstream Port Transceiver, additional logic is required to invert signal polarity on data in/out when low-speed devices are attached. My device doing as a host controller and integrate a full speed tranceriver but not include the invert signal polarity logic. Some mouse connected and work well, some failed. Because both them are standard HID, maybe not OS issue, maybe a hardware issue. I guess that the working well mouse have a transceiver invert signal polarity by itself. Am i right? Thanks! --- "M. AbuKhater" perocletos@yahoo.com> wrote:
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Hardware problem is reasonable but u should check ur hardware before anything. try on several PCs. also it is not that simple for HID devices to communicate with the host, probably someone else can help u more about that, but what I know that there is several protocol issues there , it is not possible that the logical level is inverted or not, because of the pull up resistor I told u about causes the USB to indicates the host that there is a LOWSPEED device connected to it. regards Abukhater xianshic xianshic@yahoo.com> wrote: Thanks Abukhater.
for full-speed signaling are inverted from those for
low-speed signaling. in Figure 7-14. Downstream Port
Transceiver, additional logic is required to invert
signal polarity on data in/out when low-speed devices
are attached.

My device doing as a host controller and integrate a
full speed tranceriver but not include the invert
signal polarity logic. Some mouse connected and work
well, some failed. Because both them are standard HID,
maybe not OS issue, maybe a hardware issue.

I guess that the working well mouse have a transceiver
invert signal polarity by itself. Am i right?

Thanks!

--- "M. AbuKhater"
wrote:


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__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ http://www.opencores.org/mailman/listinfo/usb --------------------------------- Do you Yahoo!? Yahoo! Search presents - Jib Jab's 'Second Term' -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums/usb/attachments/20050127/9d650819/attachment.htm