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Message
From: pranav kumar<pranav_c_java@y...>
Date: Sun Feb 20 10:52:07 CET 2005
Subject: [usb] Hub's response to 4th SSPLIT???
hi,
Sorry, i am replying so late.
Regarding your question the answer is simple, it depends on the cErr feild in the Queue Head. gernerally it is kept to a value of 3 and it decremented to 0 and if still there is no response then the transfer is halted. i.e the Host deosn't send the 4th ssplit command( if max value of cErr is 3). If Cerr is more than 3 it will continue to perform the same task it was doing before and in the 4th attempt if the SSPLIT is not corrupted and correct it will get a Ack.
Also all operations are controlled by Host so i suppose that Host doesn't send the 4th SSPLIT command for normal cases where cErr is 3.
if you find anything wrong here, kindly let me know.
Thanks and regards,
Pranav
Virendra <virendradhavale@y...> wrote:
Hi,
Can anyone plz. help me out with the following problem?
Q. After 3 consecutive corupted SSPLITs from host to hub, if the host sends a 4th SSPLIT which is correct and without any corruptions, then what should be the hub's response to this SSPLIT? (Plz. refer to Fig. A - 26 of USB 2.0 specifications on page no. 468.)
Regards,
Virendra.
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