USB bulk transfer rates above 64kbytes/sec

[daniel8]

Posted on July 07, 2008 at 16:48

USB bulk transfer rates above 64kbytes/sec

[daniel8]

Posted on May 17, 2011 at 09:54

I've looked through the demos, and none cover this issue.

I am using the VCOM example as my base, and I am trying to get around 500kb/sec transfer rates. I do not have an UART on the other end (I stripped that out).

The problem I have is that I do not seem to be able to send more than 64 bytes per frame. I know that with a full speed bus I should be able to get 19 packets per frame, or 64*19= 1.216Mb/sec

I have tried re-loading my endpoint on EP1_IN_Callback with more data, but that still didnt work. I have a fifo where I load 256bytes at a time for test, and here is my code for my endpoint callback

void EP1_IN_Callback(void)

{

char length;

char i=1;

if(fifo.num_free

//we still have data to write on this endpoint, write it.

length= read_fifo(&fifo,&us0_tx_buf[0],64);

UserToPMABufferCopy(&us0_tx_buf[0], ENDP1_TXADDR, length);

SetEPTxCount(ENDP1,length);

SetEPTxValid(ENDP1);

}

count_in =0;

}

But that does not work. Any suggestions on how to get my data rates increased above the 64k? Thanks

Daniel