Using phase interpolator information to detect a loss of lock condition during recovery of a clock signal from a received data stream
AssigneeTexas Instruments Incorporated
InventorJames B. Cho
Life of this patent
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Abstract
A loss of lock condition of a clock signal (25) recovered from a received data stream can be detected by examining conventionally available information (25, 26) indicative of a rate of change of an interpolation ratio according to which first and second phases of a local reference clock signal are combined to form the recovered clock signal.
Claims20
A method of evaluating a recovered clock signal that is recovered from a data stream received by a data communication receiver, comprising:
- the data communication receiver providing information indicative of a rate of change of an interpolation ratio according to which first and second phases of a local reference clock signal provided by the data communication receiver are combined to form the recovered clock signal;
- and
- in response to said rate of change information, determining whether a phase difference between the recovered clock signal and the local reference clock signal exceeds a predetermined amount of phase difference.
An apparatus for evaluating a recovered clock signal that a data communication receiver recovers from a data stream received by the data communication receiver, comprising:
- an input for receiving information that is provided by the data communication receiver and is indicative of a rate of change of an interpolation ratio according to which first and second phases of a local reference clock signal provided by the data communication receiver are combined to form the recovered clock signal;
- and
- circuitry coupled to said input and responsive to said rate of change information for determining whether a phase difference between the recovered clock signal and the local reference clock signal exceeds a predetermined amount of phase difference.
Dependencies are inferred from the claim text.