The 8B/10B encoder/decoder can be disabled in systems that already encode or scramble the transmitted data. I/O signals are available to create a seamless interface with both asynchronous FIFOs (i.e., CY7C42X) and clocked FIFOs (i.e., CY7C44X). A BIST pattern generator and checker allows testing of the transmitter, receiver, and the connecting link as a part of a system diagnostic check. HOTLink devices are ideal for a variety of applications where a parallel interface can be replaced with a high-speed point-to-point serial link. Applications include interconnecting workstations, servers, mass storage, and video transmission equipment.