Abstract: Certain aspects are directed to apparatus and methods for signal integrity monitoring. The method generally includes: receiving a data signal; generating a first set of delayed versions of the data signal via a plurality of delay elements; comparing each of the first set of delayed versions of the data signal with a clock signal; and generating an output signal based on the comparison.

Abstract: A delay measurement circuit includes a first skew circuit disposed proximate to a first bonding pad configured to receive a first clock signal having a first frequency. The delay measurement circuit includes a second skew circuit disposed proximate to a second bonding pad configured to receive a second clock signal having a second frequency. The first and second skew circuits each have a first mode of operation as zero-delay-return path and a second mode of operation as a synchronized pass path. The delay measurement circuit includes a pair of conductive traces coupled to the first skew circuit, another pair of conductive traces coupled to the second skew circuit, a time-to-digital converter circuit, and a switch circuit configured to selectively couple the time-to-digital converter circuit to the first skew circuit via the pair of conductive traces and the second skew circuit via the other pair of conductive traces.

Abstract: Disclosed is incorporating an IQ stream into a test signal for a receiver in motion, configuring a path for the motion of the receiver during simulation, a period of the simulation, a transmitter constellation to emulate, and a path of at least one IQ stream transmitter. Also generating signals emulating the transmitter constellation and conditioning the stream to be merged with the signals, using distance and relative motion between receiver and transmitter to determine delay and Doppler shift between transmitter and receiver in motion, scheduling sampling of the signal, including interpolation among samples of the stream, based on delay and Doppler shift, and synthesizing a conditioned stream from the interpolation between the samples, taking into account signal level of the stream, in addition to delay and shift, and merging the conditioned signal with the signals emulating the transmitter constellation and supplying the merged signals to the receiver during the test.

Abstract: Devices and methods include transmitting loopback signals for monitoring operation of a memory device. In some embodiments, a memory device may receive a system clock signal from a host device and may generate an internal clock signal based at least in part on the system clock signal. In some embodiments, the memory device may generate a loopback signal based at least in part on the internal clock signal and may transmit the loopback signal via a loopback datapath associated with the memory device. A host device may compare the internal clock signal and the system clock signal to determine a fidelity of the internal clock signal. Termination values of the memory device may be adjusted based on the determined fidelity of the internal clock signal.

Abstract: A delay locked loop includes a preprocessing module, a first regulable delay line, a second regulable delay line and a first regulation module. The preprocessing module is configured to receive an initial clock signal, preprocess the initial clock signal, and output a first clock signal and a second clock signal. The first regulable delay line is configured to receive the first clock signal, regulate and transmit the first clock signal, and output a first target clock signal. The second regulable delay line is configured to receive the second clock signal, regulate and transmit the second clock signal, and output a second synchronization clock signal. The first regulation module is configured to regulate delay of the second synchronization clock signal based on the first target clock signal, and output a second target clock signal.

Abstract: The present description concerns an electronic device including: a first input configured to receive a clock signal, coupled by a first input buffer to a first circuit; and at least an output coupled by an output buffer to the first circuit, the output buffer being synchronized on first edges of the clock signal, wherein the first input buffer includes a data input coupled to the first input and is configured to maintain the value on its output constant whatever the value on its data input during a duration following each first edge of the clock signal.

Abstract: An apparatus for correcting an error of a clock signal may include a phase adjuster that corrects an error of half-rate clock signals based on an error correction signal to output an error-corrected clock signal, a phase splitter that outputs quadrature clock signals from the error-corrected clock signal, an error detector that outputs an internal clock signal based on one of the quadrature clock signals, selects two quadrature clock signals among the quadrature clock signals based on a clock selection signal, and detects errors of the two quadrature clock signals based on an error check signal to output a correction request signal, and a controller that outputs a mode selection signal and the clock selection signal based on the internal clock signal and that outputs the error correction signal and the error check signal based on the mode selection signal, the clock selection signal, and the correction request signal.

Abstract: A semiconductor device includes a multilevel receiver including a signal determiner receiving a plurality of multilevel signals and outputting a result of mutual comparison of the plurality of multilevel signals as an N-bit signal, where N is a natural number equal to or greater than 2. A decoder restores a valid signal among the N-bit signals from the signal determiner to an M-bit data signal, where M is a natural number less than N. A clock generator receives a reference clock signal, generates an input clock signal using the reference clock signal, inputs the input clock signal to the signal determiner, and determines a phase of the input clock signal based on an occurrence probability of an invalid signal not restored to the M-bit data signal among the N-bit signals.

Abstract: This application discloses a clock synchronization system, including a quantum control processor (QCP) and N digital/analog mutual conversion devices, each digital/analog mutual conversion device including a frequency conversion module and a signal synchronization module that includes a D flip-flop (DFF). The QCP generates a global synchronization signal and reference clock signals; and transmits the global synchronization signal and a reference clock signal to the frequency conversion module and transmits the global synchronization signal to the signal synchronization module of each conversion device. The frequency conversion module performs frequency conversion processing on the reference clock signal to obtain a target clock signal, and generates a signal synchronization instruction according to the global synchronization signal; and transmits the signal synchronization instruction and the target clock signal to the signal synchronization module.

Abstract: Disclosed herein are a duty cycle monitoring method and apparatus for a memory interface, including receiving a clock signal as input and generating a first delay time offset and a second delay time offset, receiving the clock signal and the first delay time offset and then outputting a first delayed signal, receiving the first delayed signal and the second delay time offset and then outputting a second delayed signal, receiving the clock signal and the second delayed signal and then outputting a delay value corresponding to a half-period of the clock signal, and monitoring, based on the first delayed signal, whether a duty cycle of the clock signal conforms to a duty cycle specification.

Abstract: A delay device and a delay control method are provided. The delay device includes at least one current-controlled delay group and at least one switch. The at least one current-controlled delay group is coupled to a transmission wire, each of the at least one current-controlled delay group includes at least one current-controlled delayer, and each of the at least one current-controlled delayer provides a delay according to a control voltage. The at least one switch is coupled between the at least one current-controlled delay group and the transmission wire, and each of the at least one switch is turned on or off according to a bit of an enable signal applied thereto. In the disclosure, the generated delay can be dynamically adjusted and cannot be affected by parasitic capacitance.

Abstract: A line card receives a SYNC input signal and a first system clock signal. The line card generates a second system clock signal in a PLL and generates a SYNC output signal by dividing the second system clock signal in a divider circuit. The SYNC output signal is fed back as a SYNC feedback signal. The line card determines determining a closest edge of the first system clock signal to a transition of the SYNC input signal and determines a time difference between the closest edge of the first system clock signal and a transition of the SYNC feedback. The SYNC output signal is adjusted based on the time difference using a coarse adjustment by adjusting a divide ratio of the divider circuit and using a fine adjustment in the PLL based on a residue of a remainder of the time difference not accounted for by the coarse time adjustment.

Abstract: A digital phase spacing detector with programmable delay lines is described. Each programmable delay line receives a clock. The output of the programmable delay lines is compared by a logic and then passed through a glitch detector. Each of the clocks pass through the programmable delay lines that are tuned to a point where the clock edges at the output of the delay lines are aligned and glitches start appearing at the output of the logic. A calibration scheme uses replica cells (replica of VCO cells) in the measurement path. The calibration scheme calculates the average of clock phase differences through a digital control replica buffer, and this average clock phase difference is applied to the VCO delay stage cells. The PLL is then allowed to relock with the calibrated VCO delay stage cells. This process can be repeated several times to reduce the phase errors between the clock phases.

Abstract: A line card of a network box receives a SYNC input signal and generates a first time stamp based on receipt of the SYNC input signal. The line card generates a system clock signal in a phase-locked loop and generates a SYNC output signal by dividing the system clock signal in a divider circuit. The SYNC output signal is fed back to an input terminal as a SYNC feedback signal. A time stamp is generated based on receipt of the SYNC feedback signal. The line card determines a time between the SYNC input signal and the SYNC feedback signal based on the first time stamp and the second time stamp. The timing of the SYNC output signal is adjusted based on the time difference using a coarse time adjustment by adjusting a divide ratio of the divider circuit and using a fine time adjustment in the phase-locked loop based on a residue of a remainder of the time difference not accounted for by the coarse time adjustment.

Abstract: A clock data recovery circuit is provided. The clock data recovery circuit includes a charge pump circuit, a voltage controlled delay line circuit, a charge pump current generator, a phase-frequency detector and a frequency detector. The charge pump circuit generates a control voltage according to a first control signal, a second control signal and a charge pump current. The voltage controlled delay line circuit generates a data clock signal according to the control voltage and a reference clock signal. The charge pump current generator generates the charge pump current to the charge pump circuit according to the control voltage. The phase-frequency detector generates the first control signal according to a feedback clock signal and the reference clock signal. The frequency detector generates the second control signal according to the feedback clock signal and the reference clock signal.

Abstract: A test method for a delay circuit and a test circuitry are provided. The test circuitry incudes the delay circuit that essentially includes multiple serially connected logic gates, a clock pulse generator at an input end of the delay circuit for generating one or more cycles of clock signals, and a counter at an output end of the delay circuit for counting the clock signals passing through the delay circuit. The test circuitry implements a test mode by switching lines to the clock pulse generator and the counter. The test circuitry relies on a comparison result of a counting result made by the counter and a number of the cycles of the clock signals to test any failure of the delay circuit.

Abstract: The disclosure provides a voltage droop monitor (VDM) and a voltage droop monitoring method. The method includes: receiving a first reference clock signal and delaying the first reference clock signal as a first clock signal; delaying the first clock signal as a corresponding second clock signal; receiving the corresponding second clock signal from the corresponding first DCDL and generating a corresponding third clock signal via modifying a phase of the corresponding second clock signal; receiving the corresponding third clock signal; receiving a second reference clock signal; and collectively outputting a TDC code combination based on the second reference clock signal and the corresponding third clock signal, wherein the TDC code combination varies in response to a voltage variation of a to-be-monitored voltage.

Abstract: A phase-locked loop or delay locked loop provides a coarse alignment between an input clock and an output clock. A latch receiver circuit provides an indicator of a delay error between the input clock and the output clock. The delay error is used by a control circuit or state machine to adjust a fine delay that affects the output clock signal timing relative to the input clock signal. The fine delay is adjusted to minimize the timing difference between the output clock signal and the input clock signal.

Abstract: A clock recovery circuit comprises an input node receiving a data signal having a data rate, and a digital oscillator producing a local clock signal with a frequency higher than the data rate. A counter clocked by the local clock signal has its count value sampled and reset at the rising and falling edges of the data signal, and a storage block coupled to the counter stores a count value that is updated in response to the current sampled count value of the counter lying in an update range between lower and upper bounds. A threshold value set is produced as a function of the updated count value stored in the storage block. Sampling circuitry receives and samples the data signal, and provides a sampled version of the data signal in response to the count value of the counter reaching any of the threshold values.

Abstract: This disclosure is directed to enhancing PLL performance via gain calibration and duty cycle calibration. It may be desirable to perform loop gain and duty cycle calibration simultaneously. However, doing so may result in prohibitive complexity and/or area/power penalty. To enable loop gain calibration and duty cycle calibration simultaneously, the duty cycle error and the gain error may be detected in the time domain, which may enable duty cycle calibration and loop gain calibration circuitries to share a phase detector. Detecting the duty cycle error and the loop gain error in the time domain may be accomplished by implementing an analog or digital PLL system, wherein the loop gain of the PLL system is a function of the input phase offset time.

Abstract: A time delay circuit comprising a plurality of differential delay cells each having a respective time delay and being arranged in series. Each delay cell comprises first and second inverter sub-cells, each comprising a respective PMOS transistor and an NMOS transistor arranged in series such that their respective drain terminals are connected at a drain node. Each of the transistors has a back-gate terminal and is arranged such that a respective voltage applied to said back-gate terminal linearly controls its respective threshold voltage. The back-gate terminal of the PMOS transistor in each inverter sub-cell is connected to the drain node of the other sub-cell and/or the back-gate terminal of the NMOS transistor in each inverter sub-cell is connected to the drain node of the other sub-cell. A control signal varies the time delay of the delay cell by adjusting a voltage supplied to a back-gate terminal of a transistor.

Abstract: The present disclosure relates to a pipeline clock driving circuit, a computing chip, a hashboard, and a computing device.

Abstract: In a quantum computer, quantum algorithms are performed by a qubit interacting with multiple quantum control pulses. The quantum control pulses are electromagnetic RF signals that are generated digitally at baseband and sent, via asynchronous ports, to DACs that feed an RF upconversion circuit. For synchronization, each asynchronous port is coupled to a multi-tap delay line. The setting of the multi-tap delay line is determined by a function of the port's setup-and-hold time. This function is trained, via machine learning, to be applicable across a variety of ports.

Abstract: A method for determining a target locking time for a delay locked loop of a memory apparatus are provided. The method includes, a system inputting a first set of input signals to the memory apparatus in accordance with a first set of first operational parameters and a set of second operational parameters, the system measuring a first set of output signals from the memory apparatus in response to the first set of input signals to determine whether the delay locked loop fails at any combination of the first set of first operational parameters and the set of second operational parameters, the system determining a first candidate operational parameter from the first set of first operational parameters under which the delay locked loop does not fail for each of the set of second operational parameters, and the system determining the target locking time based on the first candidate operational parameter.

Abstract: In one embodiment, electronic circuitry includes a reference circuit configured to generate a reference pulse signal synchronized with a clock signal on the basis of an input pulse signal, a delay circuit configured to delay the reference pulse signal and generate a delayed pulse signal, and an output circuit configured to output a pulse train including a plurality of pulses synchronized with the clock signal on the basis of the reference pulse signal and the delayed pulse signal, and the clock signal.

Abstract: A DLL circuit (110) includes a phase delay circuit (114), a selection circuit (115), a detection circuit (117), and a clock stop circuit (116). The phase delay circuit (114) generates a plurality of delayed signals having different phases according to a clock signal. The selection circuit (115) selects one of the plurality of delayed signals as an output signal according to a setting signal. The detection circuit (117) detects a timing of switching the setting signal. The clock stop circuit (116) stops input of the clock signal to the phase delay circuit (114) for a predetermined period including the timing detected by the detection circuit (117).

Abstract: Embodiments of bidirectional repeaters and communications systems are disclosed. In an embodiment, a bidirectional repeater includes a digital state machine configured to control the bidirectional repeater to operate under a functional mode or under a bypass mode and a bypass mode driver configured to automatically detect a direction of signal through input/output (I/O) terminals of the bidirectional repeater and to allow a signal to pass through the bidirectional repeater based on the direction of signal under the bypass mode.

Abstract: Electronic devices for correcting a duty-cycle of a clock signal are disclosed. An electronic device may include circuitry configured to receive an input clock signal and generate, based on the input clock signal, a number of corrected clock signals. The circuitry may further be configured to generate, via an amplifier of the circuitry, a number of error signals based on the number of corrected clock signals and adjust a duty cycle of the number of corrected clock signals based on the number of error signals. Further, the circuitry may be configured to disable the amplifier in response to determining that the input clock signal is disabled. Associated apparatuses and methods are also disclosed.

Abstract: A phase interpolation circuit includes: a first buffer circuit configured to adjust a rise time or a fall time of a first reference clock signal based on a first control signal to generate a first input clock signal; a second buffer circuit configured to adjust a rise time or a fall time of a second reference clock signal based on a second control signal to generate a second input clock signal; a detection circuit configured to detect a rise time or a fall time of the first input clock signal or the second input clock signal and generate the first control signal and the second control signal according to a detection result thereof; and a mixer circuit configured to generate an output clock signal having a phase between a phase of the first input clock signal and a phase of the second input clock signal.

Abstract: A chip-to-chip process variation aware power efficiency optimization method that includes determining, using an adaptive voltage scaling (AVS) module of a processing unit in a system, an optimal voltage identification (VID) based on chip process variation. The method outputs the optimal VID from the AVS module to a voltage regulator of the system. The method adjusts a direct current (DC) load line setting based on the optimal VID of the processing unit in the system. The method regulates, using the voltage regulator of the system, a voltage supplied to the processing unit based on the DC load line setting.

Abstract: A “frequency shifter” is a clock synthesis system, that includes either a multiplexer or a multi-modulus divider (MMD), a fractional frequency divider, a tunable delay element, a sawtooth signal generator, in addition to other synchronization and control circuits. The generated sawtooth signal is used to control the delay of the tunable delay element, which in turn is used to adjust the phase of the signal generated by either M-to-1 multiplexer or the MMD, reducing its timing errors, and improving the spectral purity of the generated clock signal.

Abstract: Methods, systems, and devices for random number generation based on threshold voltage randomness are described. For example, a memory device may apply a voltage to a chalcogenide element and increase the applied voltage at least until the applied voltage satisfies a threshold voltage associated with the chalcogenide element. The memory device may detect the state of an oscillating signal at a time at which the applied voltage satisfies the threshold voltage, and the memory device may output a logic value corresponding to the state of the oscillating signal. The threshold voltage of the chalcogenide element may vary in a statistically random manner across voltage applications, and hence the state of the oscillating signal at the time an applied voltage reaches the threshold voltage may likewise vary in a statistically random manner, and thus the corresponding logic value that is output may be a random value suitable for random number generation.

Abstract: A duty correction circuit comprises a first delay circuit, a second delay circuit, a bang-bang driver, a duty detection circuit, and a delay control circuit. The first delay circuit delays an input clock signal to generate a first delayed clock signal. The second delay circuit delays the input clock signal based on a delay control signal to generate a second delayed clock signal. The bang-bang driver generates first and second driving clock signals from the first and second delayed clock signals based on a locking signal and a duty detection signal. The duty detection circuit may detect duty cycles of the first and second driving clock signals and generate the duty detection signal. The delay control circuit may generate the delay control signal and the locking signal based on the duty detection signal.

Abstract: An integrated circuit includes: first and second pattern generation circuits generating first and second pattern signal for a sampling section; a first section control part generating a coarse section signal for a first section of the sampling section, according to the first pattern signal; a first filter part generating a first section extract signal by filtering the second pattern signal according to the coarse section signal; a second section control part generating a fine section signal for a second section of the sampling section, according to the first section extract signal; a second filter part generating a second section extract signal by filtering the second pattern signal according to the fine section signal; an output control circuit generating a sampling enable signal according to the first and second section extract signals; and a sampling circuit suitable for sampling an input signal according to the sampling enable signal.

Abstract: A delay circuit including a first output clock generation circuit and a second output clock generation circuit. The first output clock generation circuit generates a first output clock signal by mixing phases of a first clock signal and a second clock signal based on an (n+1)-th generated delay control signal. The second output clock generation circuit generates a second output clock signal by mixing the phases of the first and second clock signals based on both an n-th generated delay control signal and the (n+1)-th generated delay control signal.

Abstract: A data receiving circuit includes a clock generation circuit, a skew adjustment circuit, a leading edge detecting circuit, and a control circuit. The clock generation circuit generates a clock signal and a decision clock signal transitioning from a second level to a first level at a time point advancing by a time of ½ of the bit cycle with respect to the clock signal, according to the received reference clock signal. The skew adjustment circuit generates a skew adjustment data signal by delaying the received data signal through a delay circuit. The leading edge detecting circuit detects a leading edge of one bit of the skew adjustment data signal to generate a leading edge detection signal. The control circuit controls the delay time of the delay circuit based on the decision clock signal and the leading edge detection signal.

Abstract: A semiconductor device includes an internal clock generation circuit configured to generate an internal clock; a plurality of unit circuits configured to have a first unit circuit and a second unit circuit operating while being synchronized with an internal clock; a plurality of transfer circuits including a first transfer circuit configured to provide a first transfer path having a first delay time, and a second transfer circuit configured to provide a second transfer path having a second delay time different from the first delay time; and a delay compensation circuit configured to compare a first clock input to the first unit circuit through the first transfer path with a second clock input to the second unit circuit through the second transfer path, and to adjust the second delay time so that the adjusted second delay time matches the first delay time.

Abstract: The present application relates to a chip test method and apparatus, a computer device, and a readable storage medium thereof. The chip test method includes: applying a test signal to a to-be-tested chip; and sending a data signal to the to-be-tested chip such that the to-be-tested chip enters a test mode based on the test signal and the data signal, and regulating a test voltage of the to-be-tested chip.

Abstract: A phase-locked loop circuit includes a voltage controlled oscillator (VCO) that generates a VCO clock in response to a voltage control signal, a divider that divides the VCO clock to output a division clock, a phase-frequency error detector that receives a reference clock and outputs a first error compensation signal, a sampler that receives the reference clock and oversamples the reference clock at a rising edge or a falling edge to output a sampling clock, a window phase error detector that receives the reference clock and outputs a second error compensation signal, a residue phase error detector that outputs a third error compensation signal, an adder that accumulates the first error compensation signal, the second error compensation signal, and the third error compensation signal to output a final error compensation signal, and a loop filter that converts and output the final error compensation signal into the voltage control signal.

Abstract: A method for operating a data interface circuit whereby calibration adjustments for data bit capture are made without disturbing normal system operation includes initially establishing, using a first calibration method where a data bit pattern received by the data interface circuit is predictable, an optimal sampling point for sampling data bits received by the data interface circuit, and during a normal system operation and without disturbing the normal system operation, performing a second calibration method where the data bit pattern received by the data interface circuit is unpredictable. The second calibration method determines an amount of a timing drift for received data bit edge transitions and adjusts the optimal timing point determined by the first calibration method to create a revised optimal timing point. The second calibration method samples fringe timing points associated with the transition edges of a data bit.

Abstract: A computer-implemented method includes an act of configuring hardware to cause at least a part of the hardware to operate as a double data rate (DDR) memory controller, and to produce a capture clock to time a read data path, where a timing of the capture clock is based on a first clock signal of a first clock, delay the first clock signal to produce a delayed first clock signal, adjust the delay such that at least one clock edge of the delayed first clock signal is placed nearer to at least one clock edge of at least one data strobe (DQS), or at least one signal dependent on a DQS timing, and produce a modified timing of the capture clock based on the delay of the first clock signal.

Abstract: A device includes a first memory die and a second memory die directly coupled to the first memory die via a first bus. The device also includes a second bus directly coupled to the first memory die. The first memory die includes a first trim circuit that when in operation adjusts a delay of signal transmission by the first memory die to a first value, while the second memory die comprises a second trim circuit that when in operation adjusts a delay of signal transmission by the second memory die to a second value.

Abstract: A circuit device includes an oscillation circuit configured to oscillate a resonator to thereby generate an oscillation signal, a waveform shaping circuit to which the oscillation signal is input, and which is configured to output a clock signal obtained by performing waveform shaping on the oscillation signal, a first duty adjustment circuit configured to perform a duty adjustment of the clock signal, and an output buffer circuit configured to output a first output clock signal and a second output clock signal to an outside based on the clock signal. The output buffer circuit includes a second duty adjustment circuit configured to perform a duty adjustment of the second output clock signal.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for lookahead duty cycle adjustment of a clock signal. Clock signals may be provided to a semiconductor device, such as a memory device, to synchronize one or more operations. A duty cycle adjuster (DCA) of the device may adjust the clock signal(s) based on a duty code determined during an initialization of the device. While the device is in operation, a lookahead DCA (LA DCA) may test a number of different adjustments to the clock signal(s), the results of which may be determined by a duty cycle monitor (DCM). The results of the DCM may be used to select one of the tested adjustments, which may be used to update the duty code.

Abstract: In one embodiment, an apparatus includes: an oscillator to output a clock signal on a first line; a switch coupled to the first line; and a voltage divider coupled to the switch. The switch may be controlled to output the clock signal through the voltage divider via the first line to a pin in a non-reset mode and prevent the clock signal from being provided to the pin in a reset mode.

Abstract: A method and system for performing duty-cycle correction (DCC) on a clock signal is provided. The method provides a two-step duty cycle correction. The method can include performing a main DCC of a single-ended clock signal, to generate a duty cycle adjusted single-ended clock signal, wherein a duty cycle of the single-ended clock signal is corrected according to a received duty-cycle continuous control signal and converting the duty cycle adjusted single-ended clock signal to differential clock signals. The method can further include performing a trim DCC by correcting a duty cycle of the differential clock signals according to a duty-cycle trim control signal received and generated in dependence upon duty cycles detected from differential output clock signals to provide error-corrected differential clock signals.

Abstract: Delay locked loop (DLL) circuitry system and a memory device are disclosed. The DLL circuitry system includes a timer unit and a DLL circuit coupled thereto. The timer unit is enabled to generate a DLL enable signal based on the signal instructing the entry into a low power consumption mode and a predefined timer condition. The DLL enable signal enables the DLL circuit to realign an internal clock signal with an external clock signal. In this way, the DLL circuit is avoided from being unable to align the internal clock signal with the external clock signal because the memory device enters the low power mode which causes the variation of the power supply voltage of the DLL circuit. Moreover, a read or write error that may occur when data is to be read or written immediately after exiting the low power consumption mode is also avoided.

Abstract: A delay locked loop circuit includes a delay line, a phase detector, a selection controller, and a charge pump. The delay line delays, based on a delay control voltage, a reference clock signal to generate an internal clock signal and a feedback clock signal. The phase detector compares phases of the internal clock signal and the feedback clock signal to generate a first detection signal and a second detection signal. The selection controller provides the reference clock signal as an up-signal and a down-signal. The charge pump generates the delay control voltage based on the up-signal and the down-signal.

Abstract: Provided herein are delay locked loops (DLLs) with calibration for external delay. In certain embodiments, a timing alignment system includes a DLL including a detector that generates a delay control signal based on comparing a reference clock signal to a feedback clock signal, and a controllable delay line configured to generate the feedback clock signal by delaying the reference clock signal based on the delay control signal. The timing alignment system further includes a delay compensation circuit that provides an adjustment to the controllable delay line to compensate for a delay of the feedback clock signal in reaching the detector.

Abstract: An apparatus for generating a frequency estimate of an output signal includes a reference signal generator configured to generate a reference clock signal. The apparatus includes frequency estimation circuitry configured to generate a cycle count based frequency estimation of the output signal based on the reference clock signal and a clock cycle count of the output signal. The frequency estimation circuitry further generates a fractional frequency estimation of the output signal based on the reference clock signal and a plurality of time-to-digital conversion phase samples of the output signal. The frequency estimation circuitry further generates the frequency estimate of the output signal using the cycle count based frequency estimation within a range and a frequency error determined from the fractional frequency estimation. The plurality of time-to-digital conversion phase samples and the cycle count based frequency estimation use a same number of reference clock cycles of the reference clock signal.