We have a BF547 VDK application that will send 100 byte messages perhaps 2 hundred times per second over a SPORT to a waiting SHARC21469. Obviously the data rate is not very high, but we want the latency to be low.
We are using SSL on the Blackfin to setup a SPORT driver using DMA. Our procedure for sending data involves submitting an ADI_DEV_1D_BUFFER containing the data, starting the SPORT dataflow, and then stopping the SPORT dataflow in a live callback once the transmit has nominally completed.
If the callback happens as a result of the DMA completion rather than the FIFO being emptied, do we run the risk of leaving data in the SPORT FIFO that will only be cleared when the next buffer is submitted 5ms later?
Thanks for any assistance.