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USB data transfer problem : 21369 EZ-kit lite + USB Extender

Question asked by granjon on May 19, 2010
Latest reply on Aug 29, 2012 by CraigG

Hy everybody,
I use VDSP++ 5.0, ADSP-21369 EZ-kit lite + USB-EZ Extender board.
I need to transfer real-time processed data from the DSP board to the host PC thanks to the USB-EZ extender board. But I need to use a sample-based algorithm (an interrupt is sent by the codec AD1835 to the SPORT0 of the DSP each time a new sample is available).
Everything works fine when I use example codes given in /Analog Devices/VisualDSP 5.0/213xx/Examples/USB EZ-EXTENDER/ (I use the bulk firmware applications USB_Loopback and USB_IO examples where you can find the "adi_dev_write" function to send data to the host PC through USB).
Everything still works fine when I use the function "adi_dev_write" in my code, but where I disabled interrupts. Unfortunately, when interrupts are enabled, the host PC application  (which uses the "ReadPipe" function given in the hostapp example) can't read any data from the USB. I think its because in my sample-based code, the function "adi_dev_write" is interrupted during the USB transfert.
Is there a solution to transfer data to the host PC even when some DSP interrupt occur during the transfer ?

 

Thanks in advance,
Pierre.

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