Abstract: A system for communicating data between a main processor and a peripheral processor over a fiber optic interface. The interface is a dedicated, point-to-point link operating in full-duplex, asynchronous mode. Dual fibers and physical layer controllers are used in a cascaded fashion to double the throughput of the interface. Frame control logic coordinates formatting of data into frames for transmission over the interface. Frame format and interface protocol are based on FDDI, but are improved to more efficiently transfer data in a point-to-point implementation. Frame Check Sequences are generated and verified to ensure error-free data transfers. Frame sending and frame receiving logic communicate with the main and peripheral processors, accepting data transfer requests and forwarding received data.