Abstract: A voltage-controlled oscillator (VCO) of ring-connected stages, where each stage in the VCO has a first set of differential inverters biased by variable bias voltages, and a second set of differential inverters biased by fixed bias voltages. The differential inverters in each stage are connected in parallel with each other. Each set of differential inverters in a stage may contain only one differential inverter. The variable bias voltages are provided by charge pumps and associated circuits as used in well-known self-biasing schemes for phase locked loops. The fixed bias voltages are provided by a biasing circuit, matched to the circuits associated with the charge pumps, but where a fixed control voltage is applied to provide the fixed bias voltages.

Abstract: A voltage-controlled oscillator (VCO) of ring-connected stages, where each stage in the VCO has a first set of differential inverters biased by variable bias voltages, and a second set of differential inverters biased by fixed bias voltages. The differential inverters in each stage are connected in parallel with each other. Each set of differential inverters in a stage may contain only one differential inverter. The variable bias voltages are provided by charge pumps and associated circuits as used in well-known self-biasing schemes for phase locked loops. The fixed bias voltages are provided by a biasing circuit, matched to the circuits associated with the charge pumps, but where a fixed control voltage is applied to provide the fixed bias voltages.

Abstract: In some embodiments, a clock generator is provided that provides a generator clock. The clock generator comprises a first clock source to provide a first clock and a second clock source to provide a second clock whose frequency at least indirectly tracks a supply to a clock distribution network. The clock generator selectably provides as the generator clock the first clock when the second clock leads the first clock and the second clock when it lags behind the first clock. Other embodiments are claimed and disclosed herein.

Abstract: According to embodiments of the present invention, a phase-locked loop (PLL) may include circuitry to select a wide pulse width for the phase-frequency detector control signal when the PLL is in a frequency acquisition stage, a narrow pulse width for the phase-frequency detector control signal when the PLL is in a phase capture stage, and a wide pulse width of the phase-frequency detector control signal when the PLL is in a lock stage.

Abstract: An embodiment of the present invention is a technique to control clock distribution to a circuit. A scheduler schedules a sequence of a clock distribution of clock signals to a plurality of clock distribution domains (CKDOMs) in the circuit according to a state status of the circuit. A controller controls enabling the clock distribution to the CKDOMs according to the scheduled sequence.

Abstract: In general, in one aspect, the disclosure describes a phase-locked loop circuit. The circuit includes an oscillator having a first control input, a second control input, and a third control input, wherein the first control input, the second control input, and the third control input act to control output frequency of the oscillator. The circuit further includes a first charge pump and a second charge pump. A first bias generator is coupled to the first control input of the oscillator and can receive electrical input from the first charge pump. A second bias generator is coupled to the second control input of the oscillator and can receive electrical input from the first charge pump, the second charge pump, and the first bias generator. A third bias generator is coupled to the third control input of the oscillator and can receive electrical input from the second charge pump and the first bias generator.

Abstract: A method, an apparatus, and a system for phase jitter measurement circuits are described herein.

Abstract: An apparatus is provided that includes a clock distribution network, a plurality of distributed oscillators provided about the clock distribution network so as to provide clock signals on the clock distribution network and a power control circuit to control power applied to the plurality of distributed oscillators. The power control circuit includes a bandgap device to produce a reference voltage based on a desired power level and a comparing/decision device to receive the reference voltage from the bandgap device and to receive the voltage signal from a source external to the apparatus. The comparing/decision device determines whether the signal received from the power source corresponds to the desired power level.

Abstract: In one embodiment, there is provided a method comprising determining a target operating point for an electronic device, the target operating point including a target operating frequency and a target operating voltage; and dynamically changing a current operating point for the electronic device including a current operating frequency and a current operating voltage by non-contemporaneously changing the current operating frequency to the target operating frequency and a current operating voltage to the target operating voltage, wherein during the changing the electronic device is in an active state.

Abstract: A system is provided that includes a phase lock loop component to output a first signal based on a reference clock signal and a feedback clock signal. A clock distribution network may distribute a clock signal based on the first signal output from the phase lock loop component. Additionally, a delay lock loop component may deskew a signal and adjust the clock signal distributed by the clock distribution network.

Abstract: A method transfers a signal from a transmitting device to a receiving device. The signal is output from the transmitting device using a driving circuit. A reference clock signal is received in the transmitting device. An output clock signal is generated according to the received reference clock signal and a feedback clock signal in a phase locked loop. A delay is provided in a path of the reference clock signal and a path of the feedback clock signal. The delay is configured to make the output signal meet a predetermined valid data timing requirement.

Abstract: A multi-loop circuit includes a first switching device to receive a first clock pulse and a second delayed pulse and produce a first output pulse including either the first clock pulse or the second delayed pulse. A first delay device receives the first output pulse and produces a first delayed pulse. A second switching device receives a second clock pulse and the first delayed pulse and produces a second output pulse including either the second clock pulse or the first delayed pulse. A second delay device receives the second output pulse and produces the second delayed pulse. A third switching device receives the first and second delayed pulses and produces a first output signal. A fourth switching device receives the first and second delayed pulses and produces a second output signal. A controller is coupled to control the first, second, third, and fourth switching devices.

Abstract: In general, in one aspect, the disclosure describes a phase-locked loop circuit. The circuit includes an oscillator having a first control input and a second control input, wherein the first control input and the second control input act to control output frequency of the oscillator. The circuit further includes a first charge pump and a second charge pump. A first bias generator is coupled to the first control input of the oscillator and can receive electrical input from the first charge pump and the second charge pump. A second bias generator is coupled to the second control input of the oscillator and can receive electrical input from the second charge pump and the first bias generator.

Abstract: A method for calibrating a delay element is described herein. In some embodiments, the method may include generating a clock signal with a clock edge, generating a reference signal with a reference edge using an adjustable delay line to delay the clock signal, and delaying a selected one of the clock signal and the reference signal through an array delay line having an array delay element with an array delay. In some embodiments, the method may further include adjusting the adjustable delay line to obtain a first adjustable delay so that the clock and reference edges are aligned on one side of the array delay element, adjusting the adjustable delay line to obtain a second adjustable delay so that the clock and reference edges are aligned on the other side of the array delay element, and ascertaining a delay difference between the first and the second adjustable delays to determine a value of the array delay provided by the array delay element.

Abstract: A method and apparatus for jitter reduction in a Phase Locked Loop (PLL) that includes determining a size of a original charge pump adequate to generate an appropriate control voltage to a Voltage Controlled Oscillator (VCO) of a PLL based on the charge pump receiving a single up signal or down signal within one cycle of a PLL input reference clock. N number of the up signal or down signal are generated to a second charge pump 1/N the size of the original charge pump. The N number of the up signal or the down signal occurs within one cycle of the PLL input reference clock. The second charge pump generates N second control voltage corrections each being 1/N the amplitude of the appropriate control voltage glitch, thus minimizing glitches on the second control voltages and reducing jitter to the VCO.

Abstract: A clock generating circuit is provided that includes a multiplexing device coupled to a clock distribution network to select between a synchronous mode and an asynchronous mode. The device may also include a plurality of distributed ring oscillators to drive the clock distribution network in the asynchronous mode. In the synchronous mode, the multiplexing device may pass a signal from a phase lock loop circuit located external to a core.

Abstract: A phase-locked loop includes a phase detector to measure a phase offset between a reference clock signal and a feedback clock signal, and to generate first and second output control signals having a pulse width corresponding to the phase offset. The phase locked loop further includes a first pulse width control circuit coupled to the phase detector to reduce the pulse width of the first output control signal producing a first modified output control signal, a second pulse width control circuit coupled to the phase detector to reduce the pulse width of the second output control signal producing a second modified output control signal, a first charge pump coupled to the phase detector to provide a first charge signal responsive to the first and second output control signals, and a second charge pump coupled to the first and second pulse width control circuits to provide a second charge signal responsive to the first and second modified output control signals.

Abstract: A method and apparatus for optimizing clock distribution in a circuit to reduce the effect of power supply noise. Parameters are determined including: a response curve of a power source for a circuit, a delay sensitivity of a clock net in the circuit to the power source, a delay sensitivity of a data net in the circuit to the power source, a data delay for the data net, and a clock delay for the clock net. The clock delay is adjusted to reduce the effect of power supply noise on the data net. The adjusting is based on the response curve of the power source, the delay sensitivity of the clock net, the delay sensitivity of the data net, the data delay, and the clock delay. The adjusting includes adding a pre-distribution clock delay.

Abstract: An apparatus and method are provided for operating a processor core. This may include a first circuit to operate at a frequency that is dependent on a power supply voltage. A frequency control circuit may be provided to control a frequency of the first circuit by directing a voltage regulator to increase or decrease the power supply voltage.

Abstract: A self-biased phase locked loop (PLL) circuit includes a charge pump to generate a control voltage, a controlled oscillator coupled to the charge pump to generate the output signal based at least in part upon the control voltage, discharge circuitry coupled to the charge pump to discharge the control voltage, and frequency detection circuitry coupled to the controlled oscillator and the discharge circuitry to generate a digital feedback signal for terminating discharge of the control voltage by the discharge circuitry when the output signal reaches a threshold frequency that is a fraction of the target frequency.