Parallel interface

After careful studying of AM335X datasheet and spent tremendous hours on  internet. I found a function called General Purpose Memory Controller(GPMC) by AM335X can provide excellent communication protocol to interface external devices, in my case, FPGA.
It is really not an easy task to understand all the GPMC features, I snapped the block diagram from the datasheet for a quick overview of GPMC.                               
Basically, I use GPMC address bus as my register location on FPGA and GPMC data as my register value, so every time I issue a command from AM335X to FPGA, my FPGA will receive the corresponding instruction to be decoded. 
Once I am able to activate GPMC on AM335X, I will be able to interface BBB to my Alter's DE2 development board.