USB Double Buffer Example

[psd]

Posted on July 23, 2009 at 17:29

USB Double Buffer Example

[psd]

Posted on May 17, 2011 at 13:18

Hi,

I need to use an USB double buffered OUT endpoint for the STM32, and I can't find an example. I only found one for the STR7. Does anyone know of one for the STM32 ? Thanks, Phil

[16-32micros]

Posted on May 17, 2011 at 13:18

Dear Phil,

For my curiosity, Why did you need a Double Buffer example ? is it for mass storage application, simple Bulk buffer transfer or for isochronous transfers.. Did you have some hints and pointers :) Cheers, STOne-32.

[psd]

Posted on May 17, 2011 at 13:18

ST-one,

I need to move large files (upto 256 MB) at high speed. Currently I have everything working with a standard bulk out endpoint. The problem is the USB driver has to NAK every other transaction while my program copies each 64 byte packet from the USB RAM. Double buffering was designed to eliminate this problem, but I am having hard time finding any simple examples for the STM32. Thanks, Phil

[16-32micros]

Posted on May 17, 2011 at 13:18

Hi psd,

Just to clarify that ''High speed'' means 480Mbps from USB point of view, which is no yet supported by STM32 :( , It runs only full speed up to 12Mbps. Cheers, STOne-32.