US 9,071,415 B2 · Semiconductor device

Abstract

A frequency tracking loop receives a result from a phase detector that detects an advance and a retard of a phase between input data and an extracted clock signal, and conducts a control to reduce a frequency deviation between the input data and the extracted clock signal. A phase interpolator adjusts a phase of the clock signal subjected to spread-spectrum frequency modulation on the basis result of the frequency deviation in the frequency tracking loop, and outputs the extracted clock signal. In the frequency tracking loop, the frequency deviation between the data signal and the clock signal is corrected to offset a variation of the frequency of the clock signal, on the basis of the frequency modulation information related to the clock signal subjected to the spread-spectrum frequency modulation which is input to the phase interpolator. The frequency of the clock signal seemingly follows the frequency of the data signal.

Claims20

Dependent claims

A semiconductor device having a clock recovery circuit, comprising:

a phase detector that detects an advance and a retard of a phase between input data and an extracted clock signal;
a frequency tracking loop that conducts a tracking control to reduce a frequency deviation between a frequency of the input data and a frequency of the extracted clock signal on the basis of a result of integrating a detection result of the phase detector together;
and
a phase interpolator that receives a clock signal subjected to spread-spectrum frequency modulation from a clock generator, adjusts a phase of the clock signal on the basis of a detection result of the frequency deviation in the frequency tracking loop, and supplies the clock signal to the phase detector as the extracted clock signal,
wherein the frequency tracking loop receives frequency modulation information corresponding to the clock signal subjected to the spread-spectrum frequency modulation from the clock generator, corrects the frequency deviation on the basis of the frequency modulation information, and offsets the frequency modulation of the clock signal.

2 more elements

A semiconductor device, comprising:

a clock generator that generates a clock signal subjected to spread-spectrum frequency modulation;
a phase detector that detects an advance and a retard of a phase between input data and an extracted clock signal, and outputs a detection result as a first control signal;
a phase interpolator that receives the clock signal subjected to the spread-spectrum frequency modulation, which is generated by the clock generator, adjusts a phase of the clock signal, and supplies the clock signal to the phase detector as the extracted clock signal;
an arithmetic unit that receives a direction of an inclination of a spread-spectrum frequency modulation waveform of the clock signal from the clock generator, and outputs a result of adding or subtracting a magnitude of the inclination of the spread-spectrum frequency modulation waveform to or from the first control signal on the basis of the direction of the inclination of the spread-spectrum frequency modulation waveform as a second control signal;
a first integrator that integrates the second control signal together, and outputs a third control signal;
a pattern generator that receives the third control signal, and outputs a fourth control signal;
a mixer that mixes the fourth control signal from the pattern generator and the first control signal from the phase detector together, and outputs a fifth control signal;
and
a second integrator that integrates the fifth control signal from the mixer together, and outputs a sixth control signal,
wherein the phase interpolator interpolates the phase of the clock signal subjected to the spread-spectrum frequency modulation on the basis of the sixth control signal from the second integrator,
wherein the semiconductor device further comprises a control circuit that outputs the magnitude of the inclination of the spread-spectrum frequency modulation waveform to a clock and data recovery circuit, and
wherein the clock generator outputs the direction of the inclination of the spread-spectrum frequency modulation waveform to the arithmetic unit of the clock and data recovery circuit.

9 more elements

Dependencies are inferred from the claim text.

Semiconductor device

Life of this patent

Semiconductor device

Life of this patent

Abstract

Claims20