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Usb bulk transfer + missing interrupt?

fa
Associate II
Posted on September 21, 2007 at 05:04

Usb bulk transfer + missing interrupt?

1 REPLY 1
fa
Associate II
Posted on September 21, 2007 at 05:04

Hello,

I am working with the STR710 and the IAR compiler.

My application runs with FreeRTOS and the ST USB lib. The USB lib is changed to fit our needs. Two interrupt endpoint and two bulk endpoints, one in each direction. The bulk endpoint is double buffered.

When I send packets on the bulk from the PC to STR710, all is working well as long as the packet size is 64. But when the packet size is eg. 6 bytes, I sometimes do not get the interrupt. But when I read the GetEPDblBuf0Count and GetEPDblBuf1Count, for endpoint 4, the count is 6 in for one of the buffers.

But when I look at the USB endpoint register CTR_RX is not set, but I can see on my USB analyzer that the 6 bytes are sent from the PC and is ack'ed by the PC. The count also indicates that the bytes are on the STR.

But where is interrupt?

Anyone who is using the Bulk endpoint, and receiving bulk packets with a small amount of data? Or any ideas why the interrupt is missing.

Best regards,

Frank Andersen