Giving external input to Triple Speed Ethernet

Yes I admit it looks strange, it seems that the TSE is waiting for something before sending the packet. But I don't see anything wrong with the way you implemented the interface.

As for your software question, are you making a baremetal application with no operating system? I'm not familiar with this setup, but if you need to be sure you could set up a breakpoint in the driver's init function and see if and when it is triggered when you run the application.