AUTO-DETECTION OF FIBER WORKING MODES

摘要

A network device is disclosed that may automatically detect the working mode of an associated communications link by searching an incoming data stream for a pattern including at least a predetermined number of continuous ones or zeros. The device is initialized to operate in a first mode compliant with 1000Base-X protocols. A SERDES associated with encoding the data stream, when operating in the first mode, ensures that there are no more than five continuous ones or zeros in the data stream. Thus, if the data stream contains the pattern of six or more continuous ones or zeros, then occurrence of the pattern results from oversampling the data stream, and thus the data rate of the network device is higher than the data rate of the communications link.