Multi-modal data-driven clock recovery circuit
AssigneeKandou Labs, S.A.
InventorsArmin Tajalli, Ali Hormati
Life of this patent
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Abstract
Multi-mode non-return-to-zero (NRZ) and orthogonal differential vector signaling (ODVS) clock and data recovery circuits having configurable sub-channel multi-input comparator (MIC) circuits for forming a composite phase-error signal from a plurality of data-driven phase-error signals generated using phase detectors in a plurality of receivers configured as ODVS sub-channel MICs generating orthogonal sub-channel outputs in a first mode and a separate first and second data driven phase-error signal from two receivers of a plurality of receivers configured as NRZ receivers in a second mode.
Claims20
A method comprising:
- in a vector signaling mode of data reception:
- utilizing a plurality of vector signaling comparators to generate a plurality of data-driven phase-error signals from a plurality of mutually-orthogonal sub-channel outputs;
- and
- generating a composite data-driven phase-error signal from the plurality of data-driven phase-error signals to adjust a local voltage-controlled oscillator (VCO) used to sample the plurality of mutually-orthogonal sub-channel outputs;
- in a non-return to zero (NRZ) signaling mode of data reception:
- operating one or more of the vector signaling comparators as NRZ-mode comparators;
- generating, for each NRZ-mode comparator, a NRZ output from a corresponding differential input signal, and adjusting a corresponding VCO used to sample the NRZ output based on a phase-error measurement made on the NRZ output.
An apparatus comprising:
- a mode controller configured to select between a vector signaling mode of data reception and a non-return-to-zero (NRZ) mode of data reception;
- a plurality of vector signaling comparators configured to generate a plurality of mutually-orthogonal sub-channel outputs from wire signals received over a plurality of wires of a multi-wire bus during the vector signaling mode of data reception;
- a phase detector configured to generate a composite data-driven phase-error as a summation of a plurality of data-driven phase-error signals generated from the plurality of mutually-orthogonal sub-channel outputs during the vector signaling mode of data reception, the phase detector configured to provide the composite data-driven phase-error signal to a local VCO used to sample the plurality of mutually-orthogonal sub-channel outputs;
- one or more of the vector signaling comparators configured to operate as a NRZ-mode comparator during the NRZ mode of data reception, each NRZ-mode comparator configured to generate a NRZ output from a corresponding differential input signal;
- and
- the phase detector configured to update corresponding VCOs based on phase-error measurements made on each NRZ output during the NRZ mode of data reception.
Dependencies are inferred from the claim text.