Abstract: A signal generating apparatus for generating a synthesized signal according to an input signal is provided. The signal generating apparatus includes a phase-locked loop device and a control unit. The phase-locked loop device has a phase/frequency detector for generating a detected signal according to a reference oscillating signal and a feedback signal, a control signal generator for generating a control signal according to the detected signal, a voltage controlled oscillator for generating the synthesized signal according to the control signal, and a divider for dividing the synthesized signal according to a dividing factor to generate the feedback signal. The control unit is for controlling the control signal generator to adjust the control signal in a calibration mode to thereby adjust a frequency of the synthesized signal. The phase/frequency detector does not output the detected signal to the control signal generator in the calibration mode.

Abstract: A frequency synthesizer is disclosed. The frequency synthesizer includes a period control word generator, a delta-sigma modulator, and a delay line unit. The period control word generator generates a period control word. The delta-sigma modulator receives the period control word and generates a phase selection signal. The delay line unit generates an output clock based on the phase selection signal. The delta-sigma modulator performs a carry-in operation based on a base number and the base number is adjustable and determined by a calibration process of the delay line unit.

Abstract: A clock generator circuit, comprising: a multi-phase clock signal generator for generating a plurality of clock signals having a same frequency but difference phases according to a reference clock signal; a modulation device for generating a phase modulation signal through Delta-Sigma modulation; and a phase modulator, which is electrically coupled to the modulation device, for selecting one of the clock signals to be a modulated clock signal according to the phase modulation signal.

Abstract: A digital PLL system includes a first multiplier coupled to a phase difference signal for multiplying the phase difference signal by a first gain factor; a second multiplier coupled to the phase difference signal for multiplying the phase difference signal by a second gain factor; a digital loop filter coupled to the first multiplier and the second multiplier for providing an integral signal and a proportional signal and for generating a control signal according to the integral signal and the proportional signal; and an auto-gain control (AGC) unit coupled to the first multiplier, the second multiplier, and the digital loop filter. The AGC unit further comprises a first control unit for updating the first gain factor according to the integral signal; and a second control unit for updating the second gain factor according to the proportional signal.

Abstract: A signal generating apparatus is disclosed for generating a synthesized signal according to an input signal, the signal generating apparatus includes a phase-locked loop device for generating the synthesized signal; a control unit for controlling the control signal generator to adjust the control signal in a calibration mode to thereby adjust a frequency of the synthesized signal, wherein the phase/frequency detector does not output the detected signal to the control signal generator in the calibration mode; a detecting device for detecting the synthesized signal to generate a calibrating signal in the calibration mode; a filtering device for filtering the input signal and calibrating the input signal according to the calibrating signal to generate a filtered signal; and a modulating device for modulating the filtered signal to generate the dividing factor.

Abstract: A jitter smoothing filter receives a direction signal and a phase error signal having a pulse width representing a phase error signal. The jitter smoothing filter generates an up proportional control signal and a down proportional control signal for driving a charge pump. For each pulse in the phase error signal, the jitter smoothing filter generates at least two pulses in the up or down proportional control signal. The number of pulses generated by the jitter smoothing filter depends on the pulse width of the corresponding pulse in the pulse error signal.

Abstract: A phase error measurement circuit and related method, and in particular a recyclable phase error measurement circuit and related method applied in a phase detector for calculating a phase error value is disclosed. A phase error measurement circuit for calculating a phase error value comprises: a multi-phase clock generator, a memory unit, and a counter. The multi-phase clock generator generates N clocks in different phases. The memory unit buffers a remainder part of the phase error value according to a phase error signal and the clocks generated from the multi-phase clock generator. The counter increments an integral part of the phase error value at each clock cycle.

Abstract: A digital PLL system includes a first multiplier coupled to a phase difference signal for multiplying the phase difference signal by a first gain factor; a second multiplier coupled to the phase difference signal for multiplying the phase difference signal by a second gain factor; a digital loop filter coupled to the first multiplier and the second multiplier for providing an integral signal and a proportional signal and for generating a control signal according to the integral signal and the proportional signal; and an auto-gain control (AGC) unit coupled to the first multiplier, the second multiplier, and the digital loop filter. The AGC unit further comprises a first control unit for updating the first gain factor according to the integral signal; and a second control unit for updating the second gain factor according to the proportional signal.

Abstract: A digital PLL system includes a first multiplier coupled to a phase difference signal for multiplying the phase difference signal by a first gain factor; a second multiplier coupled to the phase difference signal for multiplying the phase difference signal by a second gain factor; a digital loop filter coupled to the first multiplier and the second multiplier for providing an integral signal and a proportional signal and for generating a control signal according to the integral signal and the proportional signal; and an auto-gain control (AGC) unit coupled to the first multiplier, the second multiplier, and the digital loop filter. The AGC unit further comprises a first control unit for updating the first gain factor according to the integral signal; and a second control unit for updating the second gain factor according to the proportional signal.

Abstract: A phase locked loop capable of compensating for errors caused by cycle slips. The phase locked loop includes a phase detection unit for generating a phase error signal; a loop filter for filtering the phase error signal and generating a first control signal; a cycle slip detector for detecting whether a cycle slip has occurred according to the phase error signal and generating a slip indication signal; a toggling unit for toggling the selection between a first value and a second value as a compensation signal according to the slip indication signal; an accumulator for accumulating the compensation signal and generating a second control signal; an adder for adding the first control signal and the second control signal and generating a third control signal; and a controllable oscillator for generating the output clock at a frequency based on the third control signal.

Abstract: A DLL system includes a phase detector coupled to an input signal for generating a first phase error signal according to the input signal and a clock signal; an up-down counter coupled to the phase detector for generating a counting signal according to the first phase error signal; a sigma-delta modulator (SDM) coupled to the up-down counter for generating a second phase error signal according to the counting signal; an adder coupled to the SDM and the phase detector for summing the first phase error signal and the second phase error signal to generate a sum signal; a clock generator for generating a plurality of candidate clock signals according to a reference clock; and a multiplexer coupled to the clock generator and the phase detector for selecting one of the candidate clock signals to be the clock signal inputted into the phase detector according to the sum signal.

Abstract: A phase locked loop capable of compensating for errors caused by cycle slips. The phase locked loop includes a phase detection unit for generating a phase error signal; a loop filter for filtering the phase error signal and generating a first control signal; a cycle slip detector for detecting whether a cycle slip has occurred according to the phase error signal and generating a slip indication signal; a toggling unit for toggling the selection between a first value and a second value as a compensation signal according to the slip indication signal; an accumulator for accumulating the compensation signal and generating a second control signal; an adder for adding the first control signal and the second control signal and generating a third control signal; and a controllable oscillator for generating the output clock at a frequency based on the third control signal.

Abstract: A digital PLL system includes a first multiplier coupled to a phase difference signal for multiplying the phase difference signal by a first gain factor; a second multiplier coupled to the phase difference signal for multiplying the phase difference signal by a second gain factor; a digital loop filter coupled to the first multiplier and the second multiplier for providing an integral signal and a proportional signal and for generating a control signal according to the integral signal and the proportional signal; and an auto-gain control (AGC) unit coupled to the first multiplier, the second multiplier, and the digital loop filter. The AGC unit further comprises a first control unit for updating the first gain factor according to the integral signal; and a second control unit for updating the second gain factor according to the proportional signal.

Abstract: A clock recovering circuit for generating an output clock locked to an analog input signal includes: a phase detection unit for receiving the analog input signal and the feedback clock for generating a phase error signal according to the analog input signal and the feedback clock; a loop filter coupled to the phase detector for filtering the phase error signal and generating a control signal; a numerically controlled oscillator (NCO) coupled to the loop filter for generating a first clock and an index signal according to the control signal; a delay locked loop (DLL) coupled to the NCO for receiving the first clock and generating a plurality of second clocks; and a multiplexer coupled to the NCO and the DLL for selecting one of the second clocks as the output clock according to the index signal.

Abstract: A clock recovering circuit for generating an output clock locked to an analog input signal includes: a phase detection unit for receiving the analog input signal and the output clock for generating a phase error signal according to the analog input signal and the output clock; a loop filter coupled to the phase detector for filtering the phase error signal and generating a control signal; a numerically controlled oscillator (NCO) coupled to the loop filter for generating a first clock and an index signal according to the control signal; a delay locked loop (DLL) coupled to the NCO for receiving the first clock and generating a plurality of second clocks; and a multiplexer coupled to the NCO and the DLL for selecting one of the second clocks as the output clock according to the index signal.

Abstract: A clock recovering circuit for generating an output clock locked to an analog input signal includes: a phase detection unit for receiving the analog input signal and the output clock for generating a phase error signal according to the analog input signal and the output clock; a loop filter coupled to the phase detector for filtering the phase error signal and generating a control signal; a numerically controlled oscillator (NCO) coupled to the loop filter for generating a first clock and an index signal according to the control signal; a delay locked loop (DLL) coupled to the NCO for receiving the first clock and generating a plurality of second clocks; and a multiplexer coupled to the NCO and the DLL for selecting one of the second clocks as the output clock according to the index signal.

Abstract: A clock generator circuit, comprising: a multi-phase clock signal generator for generating a plurality of clock signals having a same frequency but difference phases according to a reference clock signal; a modulation device for generating a phase modulation signal through Delta-Sigma modulation; and a phase modulator, which is electrically coupled to the modulation device, for selecting one of the clock signals to be a modulated clock signal according to the phase modulation signal.

Abstract: The present invention provides a method of writing a set of binary codes into a ROM. The method is performed by forming a first photo mask and a second photo mask according to an original first code pattern, an original second code pattern, and a set of binary codes to be written into the ROM. Final first and second code patterns are formed by coupling the binary codes to be written with the original first and second code patterns by using a Boolean logical OR operation. The first and second photo masks are formed according to the final first and second code patterns. The first photolithographic process is performed using the first photo mask, and the first ion implantation process is performed; the second photolithographic process is performed using the second photo mask, and the second ion implantation process is performed. Thus the set of binary codes is written into the ROM completely and correctly.