When the XferData is called when Buffer is empty, the XferData waits until the Timeout value of the endpoint (which you can specify in your code). If the buffer doesnt get filled within the timeout, the XferData returns false. Please play around with the timeout value and see if it suits your test environment.
- Madhu Sudhan
Thanks for your comments.
Our program on FPGA chip supposed to generate pseudo data at every 1ms and fill buffer. Because the timeout is much longer than that, I think XferData cannot reach timeout. Can you tell me what I can check?