For a school project, I am developing an application for power systems protection and am using a BF609. On the board, I am trying to receive an IEC61850-9-2 packet, which follows the 802.3 Ethernet standard. I followed the example that is located in the Power On Self Test that is provided, however, I did not see how the packets are actually read. I understand that the buffer is passed to the driver, then the Callback is issued when a read occurs. Do I have to specifically call the callback sometime in my program, or does the driver do this on its own? If the driver does this on its own, then I am missing something because I have run the program for a while and the callback was never issued. Is there another example somewhere that I can test the functionality of being sent packets from another device?
Also, I have seen in many other answers the lwIP TCP/IP stack. Would this be something I should consider using in my application? I am not dealing with TCP/IP protocol at all as the IEC61850-9-2 runs over Ethernet without an overlying protocol and the packet simulation software I am using asks for the destination MAC address for the packets, in which I am inserting the MAC address of my BF609.