Integrated circuit for detecting frequency and phase of clock signal, operating method thereof, and clock and data recovery circuit including integrated circuit
View Patent ↗An integrated circuit includes a phase shifted data generation circuit, a synchronization circuit, and a control signal generation circuit configured to generate a reference clock control signal that controls at least one of a phase and a frequency of the reference clock signal by performing a logical operation on a plurality of received synchronization data.
1 . An integrated circuit, comprising:
a phase shifted data generation circuit configured to generate a plurality of phase shifted data from input data, based on a plurality of clock signals having different phases;
a synchronization circuit configured to generate a plurality of synchronization data by applying the plurality of clock signals to the plurality of received phase shifted data; and
a control signal generation circuit configured to generate a reference clock signal that controls at least one of a phase and a frequency of the reference clock signal by performing a logical operation on the plurality of synchronization data,
wherein the plurality of clock signals includes the reference clock signal and at least one phase shifted clock signal having a phase difference of a predetermined interval with respect to the reference clock signal, and
a phase interval between two pieces of data having a largest phase difference from among the plurality of synchronization data on which the logical operation is based is greater than a signal cycle of the reference clock signal.
2 . The integrated circuit of claim 1 , wherein the plurality of phase shifted data includes at least one unequal phase shifted data formed by sampling, as a target, a position having a phase difference greater than or equal to a critical phase value at a boundary between signals of the input data.
3 . The integrated circuit of claim 2 , wherein the reference clock signal operates based on a half-rate, and
the at least one phase shifted clock signal includes:
a plurality of equal clock signals having a phase difference of natural multiples of 90 degrees with respect to the reference clock signal; and
at least one unequal clock signal having a phase difference of P degree with respect to any one of the plurality of equal clock signals,
wherein P is a positive integer less than 90, and the at least one unequal phase shifted data is generated based on the at least one unequal clock signal.
4 . The integrated circuit of claim 3 , wherein the at least one phase shifted clock signal includes clock signals having a phase difference of about 45 degrees, about 90 degrees, about 180 degrees, about 270 degrees, and about 315 degrees with respect to the reference clock signal, respectively, and
the at least one unequal phase shifted data is generated based on clock signals having a phase difference of about 45 degrees and about 315 degrees with respect to the reference clock signal, respectively.
5 . The integrated circuit of claim 3 , wherein the at least one phase shifted clock signal includes clock signals having a phase difference of about 90 degrees and about 270 degrees with respect to the reference clock signal, respectively, and
the at least one unequal phase shifted data is generated based on clock signals having a phase difference of about 90 degrees and about 270 degrees with respect to the reference clock signal, respectively.
6 . The integrated circuit of claim 2 , wherein the reference clock signal operates based on a full-rate, and
the at least one phase shifted clock signal includes:
a plurality of equal clock signals having a phase difference of natural multiples of 180 degrees with respect to the reference clock signal; and
at least one unequal clock signal having a phase difference of P degree with respect to any one of the plurality of equal clock signals,
wherein P is a positive integer less than 180, and the at least one unequal phase shifted data is generated based on the at least one unequal clock signal.
7 . The integrated circuit of claim 1 , wherein the reference clock signal includes a phase control signal that controls a phase of the reference clock signal and a frequency control signal that controls a frequency of the reference clock signal.
8 . The integrated circuit of claim 1 , wherein the phase shifted data generation circuit includes a plurality of flip-flops configured to receive the plurality of clock signals one by one, and
the plurality of flip-flops is connected in parallel to each other and is each configured to output the plurality of synchronization data from the input data to the synchronization circuit.
9 . An operating method of an integrated circuit that generates a phase control signal that controls a phase of a reference clock signal and a frequency control signal that controls a frequency of the reference clock signal, based on input data and the reference clock signal, the operating method comprising:
generating a plurality of phase shifted data from the input data, based on a plurality of clock signals having different phases;
generating a plurality of synchronization data by applying the plurality of clock signals to the plurality of phase shifted data; and
generating the phase control signal and the frequency control signal by performing a logical operation on the plurality of synchronization data,
wherein the plurality of clock signals includes the reference clock signal and at least one phase shifted clock signal having a phase difference of a predetermined interval with respect to the reference clock signal, and
a phase interval between two pieces of data having a largest phase difference from among the plurality of synchronization data on which the logical operation is based is greater than a signal cycle of the reference clock signal.
10 . The operating method of claim 9 , wherein the plurality of phase shifted data includes at least one unequal phase shifted data formed by sampling, as a target, a position having a phase difference greater than or equal to a critical phase value at a boundary between signals of the input data.
11 . The operating method of claim 10 , wherein the reference clock signal operates based on a half-rate, and
the at least one phase shifted clock signal includes:
a plurality of equal clock signals having a phase difference of natural multiples of 90 degrees with respect to the reference clock signal; and
at least one unequal clock signal having a phase difference of P degree with respect to any one of the plurality of equal clock signals,
wherein P is a positive integer less than 90, and the at least one unequal phase shifted data is generated based on the at least one unequal clock signal.
12 . The operating method of claim 11 , wherein the at least one phase shifted clock signal includes clock signals having a phase difference of about 45 degrees, about 90 degrees, about 180 degrees, about 270 degrees, and about 315 degrees with respect to the reference clock signal, respectively, and
the at least one unequal phase shifted data is generated based on clock signals having a phase difference of about 45 degrees and about 315 degrees with respect to the reference clock signal, respectively.
13 . The operating method of claim 12 , wherein the at least one phase shifted clock signal includes clock signals having a phase difference of about 90 degrees and about 270 degrees with respect to the reference clock signal, respectively, and
the at least one unequal phase shifted data is generated based on clock signals having a phase difference of about 90 degrees and about 270 degrees with respect to the reference clock signal, respectively.
14 . The operating method of claim 10 , wherein the reference clock signal operates based on a full-rate, and
the at least one phase shifted clock signal includes:
a plurality of equal clock signals having a phase difference of natural multiples of 180 degrees with respect to the reference clock signal; and
at least one unequal clock signal having a phase difference of P degree with respect to any one of the plurality of equal clock signals,
wherein P is a positive integer less than 180, and the at least one unequal phase shifted data is generated based on the at least one unequal clock signal.
15 . A clock and data recovery circuit, comprising:
a phase and frequency detection circuit configured to generate a phase control signal that controls a phase of a reference clock signal and a frequency control signal that controls a frequency of the reference clock signal, based on input data and the reference clock signal;
a loop filter configured to generate a frequency control word that controls a frequency of the reference clock signal, based on the received phase control signal and the frequency control signal; and
an oscillator configured to generate the reference clock signal by oscillating based on the received frequency control signal,
wherein the phase and frequency detection circuit is configured to generate the frequency control signal by performing a logical operation on a plurality of first data generated based on the received reference clock signal and the input data, and
a phase interval between two pieces of data having a largest phase difference from among the plurality of first data on which the logical operation is based is greater than a signal cycle of the reference clock signal.
16 . The clock and data recovery circuit of claim 15 , wherein the plurality of first data includes at least one unequal data formed by sampling, as a target, a position having a phase difference greater than or equal to a critical phase value at a boundary between signals of the input data.
17 . The clock and data recovery circuit of claim 16 , wherein the oscillator is configured to generate the reference clock signal based on a half-rate,
wherein the plurality of first data includes:
a plurality of equal clock data having a phase difference of natural multiples of 90 degrees with respect to the reference clock signal; and
at least one unequal clock data having a phase difference of P degree with respect to any one of the plurality of equal clock data,
wherein P is a positive integer less than 90, and the at least one unequal data is generated based on the at least one unequal clock data.
18 . The clock and data recovery circuit of claim 17 , wherein the plurality of first data includes data having a phase difference of about 45 degrees, about 90 degrees, about 180 degrees, about 270 degrees, and about 315 degrees with respect to the reference clock signal, respectively, and
the at least one unequal data is generated based on data having a phase difference of about 45 degrees and about 315 degrees with respect to the reference clock signal, respectively.
19 . The clock and data recovery circuit of claim 17 , wherein the plurality of first data includes data having a phase difference of about 90 degrees and about 270 degrees with respect to the reference clock signal, respectively, and
the at least one unequal data is generated based on data having a phase difference of about 90 degrees and about 270 degrees with respect to the reference clock signal, respectively.
20 . The clock and data recovery circuit of claim 16 , wherein the oscillator is configured to generate the reference clock signal based on a full-rate,
the plurality of first data includes:
a plurality of equal clock data having a phase difference of natural multiples of 180 degrees with respect to the reference clock signal; and
at least one unequal clock data having a phase difference of P degree with respect to any one of the plurality of equal clock data,
wherein P is a positive integer less than 180, and the at least one unequal data is generated based on the at least one unequal clock data.