Daffer McDaniel, LLP
Circuit, system, and method for preventing a communication system absent a dedicated clocking master from producing a clocking frequency outside an acceptable range
A communication system, clock recovery circuit, and method are provided for allowing data to be transmitted across a communication system and between clock recovery circuits absent a clock master specifically designed for one node of the communication system. Absent a clock master, the communication system is permitted to enter into an all slave mode, with periodic unlock conditions possibly rotating about the communication system ring topology. However, the unlock condition can be readily detected and if the received data bitstream formed into a recovered clock exceeds a threshold above or is less than a threshold below a reference clock generated during instances of unlock, then the clock recovery circuit will fix the synchronizing clock to the reference clock, and cause the bitstream to resynchronize to the reference clock before the reference clock is again disabled to allow the communication system to re-enter the all slave and rotating unlock condition. Periodic application of a reference clock interspersed with periodic application of a clock having transitions equal to the incoming bitstream proves advantageous in avoiding a design where a dedicated master must be used within a specified communication system node.
Standard Microsystems Corporation
H
H04L
inventional
Jason E. David J.
Lewis Knapp