Abstract: Clock circuits and apparatus containing such are useful in clock synchronization and skew adjustment. Such clock circuits may include a delay line coupled to receive an input signal, wherein the delay line comprises a plurality of delay elements, and wherein at least two delay elements of the plurality of delay elements differ in unit time delay. Such clock circuits may further include a phase detector coupled to receive the input signal and a signal generated from an output signal of the delay line. The phase detector may be configured to compare the input signal to the generated signal and to adjust a length of the delay line to synchronize the input signal and the generated signal.

Abstract: Embodiments disclosed herein provide an apparatus comprising a clock generation circuit configured to generate a first signal for a first time period and a second signal for a second time period, a charge pump circuit coupled to the clock generation circuit and configured to generate a first voltage and a second voltage based, at least in part, on the first time period and the second time period, and a comparison circuit coupled to the charge pump circuit, the comparison circuit configured to compare a difference between the first voltage and the second voltage with a threshold value and generate an active tracking enablement signal in response to determining that the difference between the first and second voltages exceeds the threshold value.

Abstract: Embodiments disclosed herein provide an apparatus comprising a clock generation circuit configured to generate a first signal for a first time period and a second signal for a second time period, a charge pump circuit coupled to the clock generation circuit and configured to generate a first voltage and a second voltage based, at least in part, on the first time period and the second time period, and a comparison circuit coupled to the charge pump circuit, the comparison circuit configured to compare a difference between the first voltage and the second voltage with a threshold value and generate an active tracking enablement signal in response to determining that the difference between the first and second voltages exceeds the threshold value.

Abstract: Embodiments disclosed herein provide an apparatus comprising a clock generation circuit configured to generate a first signal for a first time period and a second signal for a second time period, a charge pump circuit coupled to the clock generation circuit and configured to generate a first voltage and a second voltage based, at least in part, on the first time period and the second time period, and a comparison circuit coupled to the charge pump circuit, the comparison circuit configured to compare a difference between the first voltage and the second voltage with a threshold value and generate an active tracking enablement signal in response to determining that the difference between the first and second voltages exceeds the threshold value.

Abstract: Apparatuses, methods, and delay circuits for delaying signals are described. An example apparatus includes a fine delay circuit configured to provide an output signal based on a ratio of a first input signal and a second input signal. The fine delay circuit including a phase mixer circuit including first signal drivers configured to receive the first input signal. The fine delay circuit further including second signal drivers configured to receive the second input signal, where at least two of the first signal drivers have different drive strengths and at least two of the second signal drivers have different drive strengths.

Abstract: Apparatuses and methods are directed to preventing duty cycle distortion in an electronic apparatus. The apparatus generally includes a first phase mixer stage configured to interpolate a first and a second input signal to provide a first intermediate signal and further configured to interpolate the second input signal and a third input signal to provide a second intermediate signal, the first phase mixer stage distorting duty cycle in providing the first intermediate signal. The apparatus further includes a second phase mixer stage configured to interpolate the first intermediate signal and the second intermediate signal to provide an output signal and further configured to compensate for duty cycle distortion of the first phase mixer stage.

Abstract: Embodiments disclosed herein provide an apparatus comprising a clock generation circuit configured to generate a first signal for a first time period and a second signal for a second time period, a charge pump circuit coupled to the clock generation circuit and configured to generate a first voltage and a second voltage based, at least in part, on the first time period and the second time period, and a comparison circuit coupled to the charge pump circuit, the comparison circuit configured to compare a difference between the first voltage and the second voltage with a threshold value and generate an active tracking enablement signal in response to determining that the difference between the first and second voltages exceeds the threshold value.

Abstract: Apparatuses and methods are directed to preventing duty cycle distortion in an electronic apparatus. The apparatus generally includes a first phase mixer stage configured to interpolate a first and a second input signal to provide a first intermediate signal and further configured to interpolate the second input signal and a third input signal to provide a second intermediate signal, the first phase mixer stage distorting duty cycle in providing the first intermediate signal. The apparatus further includes a second phase mixer stage configured to interpolate the first intermediate signal and the second intermediate signal to provide an output signal and further configured to compensate for duty cycle distortion of the first phase mixer stage.

Abstract: This disclosure relates to delay line test circuits and methods. In one aspect, an integrated circuit (IC) can include a plurality of delay lines, a selection circuit, a delay comparison circuit, and a control circuit. The plurality of delay lines can generate a plurality of delayed clock signals, and the selection circuit can include a plurality of inputs configured to receive at least the plurality of delayed clock signals. The selection circuit can generate a first output clock signal and a second output clock signal by selecting amongst signals received at the plurality of inputs based on a state of a selection control signal. The delay comparison circuit can compare a delay of the first output clock signal to a delay of the second output clock signal and can generate a delay comparison such as a pass/fail flag based on the result. The control circuit can generate the selection control signal.

Abstract: Apparatuses and methods for compensating for differing power supply sensitivities of a circuit in a clock path. One such method includes altering signal timing of at least one of reference and feedback clock signals differently according to variations in power supply voltage to compensate for differences in delay power supply sensitivities of delays of a forward clock path and of a feedback clock path. Another example method includes providing an output clock signal in phase with an input clock signal and compensating for delay error between delays used in providing at least some of the delay of the output clock signal relative to the input clock signal by providing delays having power supply sensitivities resulting in a combined power supply sensitivity that is inverse to the delay error.

Abstract: A circuit and method for generating an active output signal in response to detecting N events, which are represented by an event signal. A counter circuit is configured to increment and decrement through a sequence of values in response to the event signal. Detection logic coupled to the counter circuit is configured to detect at least first and second values of the sequence. The detection logic is further configured to generate the active output signal and switch to detecting the second value in response to detecting the first value and generate the active output signal and switch to detecting the first value in response to detecting the second value. The first and second values are separated by N counts.

Abstract: Apparatuses and methods for compensating for differing power supply sensitivities of a circuit in a clock path. One such method includes altering signal timing of at least one of reference and feedback clock signals differently according to variations in power supply voltage to compensate for differences in delay power supply sensitivities of delays of a forward clock path and of a feedback clock path. Another example method includes providing an output clock signal in phase with an input clock signal and compensating for delay error between delays used in providing at least some of the delay of the output clock signal relative to the input clock signal by providing delays having power supply sensitivities resulting in a combined power supply sensitivity that is inverse to the delay error.

Abstract: A system and method are disclosed to accomplish power savings in an electronic device, such as a memory chip, by performing selective frequency locking and subsequent instantaneous frequency switching in the DLL (delay locked loop) used for clock synchronization in the electronic device. By locking the DLL at a slow clock frequency, the operational frequency may be substantially instantaneously switched to an integer-multiplied frequency of the initial locking frequency without losing the DLL lock point. This DLL locking methodology allows for faster frequency changes from higher (during normal operation) to lower (during a power saving mode) clock frequencies without resorting to gradual frequency slewing to conserve power and maintain DLL locking. Hence, a large power reduction may be accomplished substantially instantaneously without adding complexity to the system clock generator. Because of the rules governing abstracts, this abstract should not be used in construing the claims.

Abstract: Locked state detection circuits, devices, systems, and methods for detecting a locked or synchronized state of a clock synchronization circuit are described. Detection of a locked state includes a circuit including a phase detector configured to generate a delay adjustment signal in response to comparison of a forward path signal indicative of an external clock signal and a feedback path signal indicative of an output clock signal. The circuit further includes a trend detector operably coupled to the delay adjustment signal and configured to generate a locked signal indicative of an in-phase steady-state between the external clock signal and the output clock signal.

Abstract: Apparatuses, methods, and delay circuits for delaying signals are described. An example apparatus includes a fine delay circuit configured to provide an output signal based on a ratio of a first input signal and a second input signal. The fine delay circuit including a phase mixer circuit including first signal drivers configured to receive the first input signal. The fine delay circuit further including second signal drivers configured to receive the second input signal, where at least two of the first signal drivers have different drive strengths and at least two of the second signal drivers have different drive strengths.

Abstract: Apparatuses and methods for compensating for differing power supply sensitivities of a circuit in a clock path. One such method includes altering signal timing of at least one of reference and feedback clock signals differently according to variations in power supply voltage to compensate for differences in delay power supply sensitivities of delays of a forward clock path and of a feedback clock path. Another example method includes providing an output clock signal in phase with an input clock signal and compensating for delay error between delays used in providing at least some of the delay of the output clock signal relative to the input clock signal by providing delays having power supply sensitivities resulting in a combined power supply sensitivity that is inverse to the delay error.

Abstract: This disclosure relates to delay line test circuits and methods. In one aspect, an integrated circuit (IC) can include a plurality of delay lines, a selection circuit, a delay comparison circuit, and a control circuit. The plurality of delay lines can generate a plurality of delayed clock signals, and the selection circuit can include a plurality of inputs configured to receive at least the plurality of delayed clock signals. The selection circuit can generate a first output clock signal and a second output clock signal by selecting amongst signals received at the plurality of inputs based on a state of a selection control signal. The delay comparison circuit can compare a delay of the first output clock signal to a delay of the second output clock signal and can generate a delay comparison such as a pass/fail flag based on the result. The control circuit can generate the selection control signal.

Abstract: Apparatuses, methods, and delay circuits for delaying signals are described. An example apparatus includes a fine delay circuit configured to provide an output signal based on a ratio of a first input signal and a second input signal. The fine delay circuit including a phase mixer circuit including first signal drivers configured to receive the first input signal. The fine delay circuit further including second signal drivers configured to receive the second input signal, where at least two of the first signal drivers have different drive strengths and at least two of the second signal drivers have different drive strengths.

Abstract: Clock circuits and apparatus containing such are useful in clock synchronization and skew adjustment. Such clock circuits may include a delay line coupled to receive an input signal, wherein the delay line comprises a plurality of delay elements, and wherein at least two delay elements of the plurality of delay elements differ in unit time delay. Such clock circuits may further include a phase detector coupled to receive the input signal and a signal generated from an output signal of the delay line. The phase detector may be configured to compare the input signal to the generated signal and to adjust a length of the delay line to synchronize the input signal and the generated signal.

Abstract: Apparatuses, methods, and delay circuits for delaying signals are described. An example apparatus includes a fine delay circuit configured to provide an output signal based on a ratio of a first input signal and a second input signal. The fine delay circuit including a phase mixer circuit including first signal drivers configured to receive the first input signal. The fine delay circuit further including second signal drivers configured to receive the second input signal, where at least two of the first signal drivers have different drive strengths and at least two of the second signal drivers have different drive strengths.