CLOCK AND DATA RECOVERY CIRCUIT
First Claim
Patent Images
1. A clock and data recovery circuit, comprising:
- a first phase detector, comparing a phase of a data signal with that of a first clock signal to output a first output signal, wherein the first output signal indicates whether the phase of data signal is ahead or behind that of the first clock signal;
an auxiliary module, comprising;
an auxiliary clock generator, generating an auxiliary clock signal;
a second phase detector, coupled to the auxiliary clock generator, comparing a phase of the auxiliary clock signal with that of the first clock signal to output a second output signal, wherein the second output signal indicates whether the phase of the auxiliary clock signal is ahead or behind that of the first clock signal; and
a multiplexing selecting unit, coupled to the first phase detector and the second phase detector, outputting a multiplexing output signal according to a selection signal;
a first charge pump, coupled to the multiplexing selecting unit, outputting a control signal according to the multiplexing output signal; and
a first voltage-controlled oscillator (VCO), coupled to the first charge pump, generating the first clock signal according to the control signal;
wherein the second phase detector comprises;
a first delay unit, receiving the auxiliary clock signal and the first clock signal to generate a first delayed signal;
a second delay unit, coupled to the first delay unit, receiving the first delayed signal and the first clock signal to generate a second delayed signal;
a first exclusive OR (XOR) gate, performing an XOR operation on the auxiliary clock signal and the first delayed signal to generate a first rising signal; and
a second XOR gate, performing an XOR operation on the first delayed signal and the second delayed signal to generate a first falling signal;
wherein, the first rising signal and the first falling signal form the second output signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A clock and data recovery circuit includes a first phase detector, a first charge pump, a first voltage-controlled oscillator (VCO), and an auxiliary module. The auxiliary module includes: an auxiliary clock generator, generating an auxiliary clock signal; a second phase detector, coupled to the auxiliary clock generator, comparing a phase of the auxiliary clock signal with that of a first clock signal outputted by the first VCO; and a multiplexing selecting unit, outputting a multiplexing output signal to the first charge pump according to a selection signal.
9 Citations
12 Claims
-
1. A clock and data recovery circuit, comprising:
-
a first phase detector, comparing a phase of a data signal with that of a first clock signal to output a first output signal, wherein the first output signal indicates whether the phase of data signal is ahead or behind that of the first clock signal; an auxiliary module, comprising; an auxiliary clock generator, generating an auxiliary clock signal; a second phase detector, coupled to the auxiliary clock generator, comparing a phase of the auxiliary clock signal with that of the first clock signal to output a second output signal, wherein the second output signal indicates whether the phase of the auxiliary clock signal is ahead or behind that of the first clock signal; and a multiplexing selecting unit, coupled to the first phase detector and the second phase detector, outputting a multiplexing output signal according to a selection signal; a first charge pump, coupled to the multiplexing selecting unit, outputting a control signal according to the multiplexing output signal; and a first voltage-controlled oscillator (VCO), coupled to the first charge pump, generating the first clock signal according to the control signal; wherein the second phase detector comprises; a first delay unit, receiving the auxiliary clock signal and the first clock signal to generate a first delayed signal; a second delay unit, coupled to the first delay unit, receiving the first delayed signal and the first clock signal to generate a second delayed signal; a first exclusive OR (XOR) gate, performing an XOR operation on the auxiliary clock signal and the first delayed signal to generate a first rising signal; and a second XOR gate, performing an XOR operation on the first delayed signal and the second delayed signal to generate a first falling signal; wherein, the first rising signal and the first falling signal form the second output signal. - View Dependent Claims (3, 4, 5, 6, 10, 11, 12)
-
-
2. (canceled)
-
7. A clock and data recovery circuit, comprising:
-
a first phase detector, comparing a phase of a data signal with that of a first clock signal to output a first output signal, wherein the first output signal indicates whether the phase of data signal is ahead or behind that of the first clock signal; an auxiliary module, comprising; an auxiliary clock generator, generating an auxiliary clock signal; a second phase detector, coupled to the auxiliary clock generator, comparing a phase of the auxiliary clock signal with that of the first clock signal to output a second output signal, wherein the second output signal indicates whether the phase of the auxiliary clock signal is ahead or behind that of the first clock signal; and a multiplexing selecting unit, coupled to the first phase detector and the second phase detector, outputting a multiplexing output signal according to a selection signal; a first charge pump, coupled to the multiplexing selecting unit, outputting a control signal according to the multiplexing output signal; and a first voltage-controlled oscillator (VCO), coupled to the first charge pump, generating the first clock signal according to the control signal; wherein the auxiliary clock generator comprises; a phase frequency detector, receiving an input clock signal; a second charge pump, coupled to the phase frequency detector; and a second VCO, coupled between the second charge pump and the phase frequency detector, generating the auxiliary clock signal. - View Dependent Claims (8, 9)
-
Specification