Determining a locked status of a clock tracking circuit
AssigneeMicrochip Technology Incorporated
InventorsWilliam Roberts, Waleed El-halwagy, Youcef Fouzar, Kristopher Kshonze
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Abstract
An example apparatus includes a phase detector, a digital discriminator, and a logic circuit. A status signal of the phase detector is at least partially based on a phase relationship between a reference clock and a feedback clock, the feedback clock generated by a clock tracking circuit to track the reference clock. The digital discriminator may sample the status signal of the phase detector. The logic circuit may determine a locked status of the clock tracking circuit at least partially based on samples of the status signal of the phase detector.
Claims21
An apparatus, comprising:
- a phase detector, wherein a status signal of the phase detector is at least partially based on a phase relationship between a reference clock and a feedback clock, the feedback clock generated by a clock tracking circuit to track the reference clock;
- a digital discriminator to sample the status signal of the phase detector;
- and
- a logic circuit to determine a locked status of the clock tracking circuit at least partially based on samples of the status signal of the phase detector.
A method, comprising:
- setting a status signal of a phase detector, wherein the status signal of the phase detector is set at least partially based on a phase relationship between a reference clock and a feedback clock generated by a clock tracking circuit to track the reference clock, the phase relationship between the reference clock and the feedback clock being at least partially based on a relationship between a phase threshold and an amount of difference between the reference clock and the feedback clock;
- and
- generating a signal indicative of a locked status of the clock tracking circuit at least partially based on the status signal of the phase detector.
A method, comprising:
- detecting occurrences of like respective edges of a reference clock and a feedback clock generated by a clock tracking circuit to track the reference clock;
- setting a status signal of a phase detector to indicate whether or not the detected occurrences of like respective edges were within a predetermined range;
- and
- generating a signal indicative of a locked status of the clock tracking circuit at least partially based on the status signal of the phase detector.
Dependencies are inferred from the claim text.