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imx25 OTG(device) ISOC multi-transaction issue

Question asked by tom fang on Feb 9, 2014
Latest reply on Mar 4, 2014 by Karina Valencia Aguilar
Branched to a new discussion

Hi guys:

I have a project using imx25 and a sensor to make a webcam,

using imx25 OTG device function to connect a host, video data transfered in ISOC endpoint,

software is your linux-2.6.31 SDK, now all functions are ok, but there is a problem:

 

if I configure this endpoint worked in "1 transaction", video data can be transfered, but the frame rate is only around 10,

for improving frame rate, I try to configure the endpoint worked in "3 transactions", but there isn't any data in USB line.

 

how can i do to make the "3 transactions" work?

 

I attached some pictures from USB analysis:

<<one transaction.PNG>>: configure imx25 ISOC endpoint worked in "1 transaction".

<<three transaction.PNG>>: configure imx25 ISOC endpoint worked in "3 transaction".

<<one transaction microsoft.PNG>>: microsoft webcam worked in "1 transaction".

<<isoc register>>: "1 transaction" and "3 transactions" configuration table from imx25 data sheet.

 

waiting for your response from heart.

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