Hi, Xilinx have filed for 22 patents to implement 8B/10B algorithm.
IBM filed the 8B/10B original patent in 1981. Now 8B/10B algorithms are so popular that all SERDES specifications use the 8B/10B like what ASCII is to computer industry.
Most of 22 Xilinx 8B/10B patents are pending. You may print out what have been approved as a patent. Their experiences will certainly help you do understand how to design a 8B/10B circuit.
Sorry, all those circuits are still pending. One that is approved is a software flow map.
Weng