Yeah I mean I guess I'm looking for what options there are for interfacing with computers in a standard way. I get needing to implement something like SPI or I2C or etc but I'm curious to know what the best options are, especially if you are wanting to interface with PCIe.
Is it best to interface directly with the PCIe bus from the FPGA? Is it better to abstract with some kind of IC? Is the board or the computer the master clock? Is there some kind of encoding scheme that needs to be adhered to?