I have been able to get the SPORT loopback example running on the 408-EZKIT. In that example, the 1/2 SPORTs are opened, TX RX channels configured, Buffers submitted, TX RX channels enabled. The data is sent and received and the TX RX channels are disabled. All is well and good for a single transmission. I wanted to do more than a single transmission so I modified the code to operate as follows:
The 1/2 SPORTs are opened, TX RX channels configured, Buffers submitted, TX RX channels enabled and data is sent and received. I don't disable the TX RX channels and simply loop back to buffer submission and data sending. That loop operates correctly for 3 iterations and then fails buffer submission. Experimenting I found that I have to disable the TX RX channels before buffer submission. Is that correct behavior? Meaning a channel has to be closed before any subsequent buffer submission????