2008-07-07 07:48 AM
USB bulk transfer rates above 64kbytes/sec
2011-05-17 12:54 AM
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