Abstract: An apparatus for implementing a digital phase-locked loop includes a voltage-controlled oscillator that generates a primary clock signal in response to a VCO control voltage. Detection means generates counter control signals, including count up signals and count down signals, to indicate a current relationship between the primary clock signal and a reference signal. An up/down counter then either increments or decrements a counter value in response to corresponding counter control signals. The counter value is then converted by a digital-to-analog converter into the VCO control voltage for adjusting the frequency of the primary clock signal generated by the voltage-controlled oscillator. In alternate embodiments, the foregoing up/down counter may be utilized to adjust the frequency of the voltage-controlled oscillator in proportion to the counter value by utilizing appropriate techniques other than generating a VCO control voltage with a digital-to-analog converter.

Abstract: A phase detecting module includes a phase detecting unit, a comparator and a counter. The phase detecting unit is arranged to compare a first input signal and a second input signal to generate a phase detecting result. The comparator is arranged to compare the phase detecting result and a predetermined voltage to generate a comparing result. The counter is arranged to count one of the first input signal and the second input signal to generate a counting value. The phase detecting result and the counting value are reset if the counting value reaches a predetermined value, and the comparing result is outputted to a target device from the comparator if the counting value reaches a predetermined value.

Abstract: A time-to-digital converter includes low and high resolution time-to-digital converters for providing both high resolution and wide measurement range. The low resolution time-to-digital converter measures a time difference between first and second signals with a first quantization step. The high resolution time-to-digital converter measures the time difference between the first and second signals with a second quantization step that is smaller than the first quantization step. The low resolution time-to-digital converter has a wider measurement range than the high resolution time-to-digital converter.

Abstract: A method of controlling the output of data from a memory device includes deriving from an external clock signal a read clock and a control clock for operating an array of storage cells, both the read clock and the control clock each being comprised of clock pulses. A value is preloaded into one or both of a first counter located in the read clock domain and a second counter located in the control clock domain such that the difference in starting counts between the two counters is equal to a column address strobe latency (L) minus a synchronization (SP) overhead. A start signal is generated for initiating production of a running count of the read clock pulses in the first counter. The input of the start signal to the second counter is delayed so as to delay the initiation of a running count of the control clock pulses. A value of the second counter is held in response to a read command.

Abstract: A phase generator includes a phase-shift enable and disable signal generator connected to configuration bits at its first input and connected to a reset signal at its reset input for generating a control signal; the configuration bits corresponding to the phase shift desired. The phase generator includes a logic signal generation device connected at its control input to the output of the phase-shift enable and disable signal generator and connected to a reset signal at its reset input for providing a phase generating signal; and a feedback element connected between the output of the logic signal generation device and control input of the phase-shift enable and disable signal generator for providing controlled clock signal to the phase-shift enable and disable signal generator.

Abstract: The accuracy of the delay amount to be imparted to a timing signal is improved by increasing the delay amount obtained by a first stage of a delay element. A variable delay 50 which comprises a DA converter 51 which supplies current 51 based on delay setting data; a delay element 53 which imparts a delay amount Tpd to a prescribed signal and outputs the signal; and a bias circuit 52 which is connected such that the amount of current flown in the DA converter 51 and the amount of current flown in the delay element 53 become equal, wherein the DA converter 51 allows the relationship between the delay setting data DATA and the current Id to be hyperbolic (inversely proportional). As a result, the relationship between the delay setting data DATA and the delay amount Tpd can be linear, whereby the delay amount obtained by a first stage of the delay element can be widened.

Abstract: A system for automatically calibrating a crystal of a communication device and a method thereof are described. The system comprises a timing generator for generating a timing signal, a timing adjustment device coupled with the timing generator and for adjusting the timing of the timing signal responsive to receipt of an adjustment signal, and a calibration device coupled with the timing adjustment device and arranged to transmit the adjustment signal responsive to a comparison between the timing signal and a reference signal.

Abstract: The semiconductor device is provided with a clock signal generation circuit that includes a reference clock signal generation circuit which generates a first reference clock signal, a first counter circuit which counts the number of rising edges of the first reference clock signal by using the first reference clock signal and a synchronizing signal, a second counter circuit which counts the number of rising edges of the first reference clock signal by using an enumerated value of the first counter circuit, a first divider circuit which divides a frequency of the first reference clock signal by using the enumerated value of the first counter circuit and generates a second reference clock signal, and a second divider circuit which divides a frequency of the second reference clock signal and generates a clock signal.

Abstract: A clock multiplier for multiplying an input clock by N includes a phase/frequency detector, a clock selector, and a voltage-controlled delay line. The phase/frequency detector generates a first control signal and a second control signal according to a frequency/phase difference between the input clock and a count signal indicating a signal that is generated by delaying the input clock N times. The clock selector selects one of the input clock and a feedback clock based on the input clock and the count signal. The voltage-controlled delay line adjusts a delay time of the selected signal according to a control voltage that is generated based on the first control signal and the second control signal, and outputs the feedback clock based on the adjusted signal. The clock multiplier operates without accumulating a frequency/phase difference between the input clock and the output clock when the multiplying ratio is increased.

Abstract: A data output strobe signal generating circuit includes a duty cycle correcting unit that corrects the duty ratio of an input clock in response to a control signal to generate a corrected clock. A data output strobe signal generating unit receives the corrected clock and generates a data output strobe signal. A duty cycle control unit receives the data output strobe signal and outputs the control signal.

Abstract: A frequency-locking device including a digitally-controlled oscillator (DCO) and a comparing unit is disclosed. The DCO is used for generating an output frequency signal. The comparing unit receives a Keep Alive signal from a universal serial bus (USB) and the output frequency signal, and compares the Keep Alive signal with the output frequency signal to generate a calibration signal. Then, the DCO adjusts the frequency of the output frequency signal according to the calibration signal to meet the USB specification for data communication.

Abstract: A device in which a clock generation circuit is connected to a counter circuit for controlling operation timing of a DLL circuit or the like, and the counter circuit is intermittently operated by intermittently supplying a clock signal to the counter circuit from the clock generation circuit.

Abstract: A phase difference detector for detecting a phase difference between input clocks which both have a same first frequency, including: a pulse width conversion unit for converting the input clocks into a phase difference signal indicating by a pulse width a phase difference between the input clocks; and a counter unit which samples a level of the phase difference signal using a reference clock having a second frequency which is slower than the first frequency, and counts the number of levels of the phase difference signal using a first weighting according to the sampled level of the phase difference signal. When the count value of the counter unit transits in a predetermined range, the phase difference between the input clocks is detected according to the first weighting.

Abstract: A scalable DLL (delay locked loop) circuit that has a calibration mechanism to auto tune locking precision. The delay locked loop circuit includes a multi-phase phase locked loop circuit for generating a plurality of phase signals according to a system clock, wherein one of the phase signals is a pixel clock; a phase detector for detecting an integral phase error and a fractional phase error between a reference signal and a feedback signal according to the pixel clock; a phase selector for selecting one of the phase signals according to the fractional phase error; and a delay circuit for shifting the phase of the reference signal according to the integral phase error and the selected phase signal to generate an output signal.

Abstract: An adjustable digital lock detector for a phase-locked loop (PLL) has a variable counter for outputting an output signal corresponding to a first clock signal, a target count number signal, and a count number offset signal, a latch for sampling the output signal of the variable counter and outputting a latch output signal according to a result of sampling the output signal, a lead/lag detector for receiving the latch output signal and outputting the count number offset signal according to a predetermined state of the latch output signal, and an arbiter for receiving the latch output signal and outputting an arbiter output signal according to the latch output signal and a second clock signal.

Abstract: A semiconductor integrated circuit is provided with a voltage level detector which detects a voltage level of a signal wire, and a transition time detector which detects a time length of a transition period during which the signal wire changes from an inactive voltage state to an active voltage state based on the voltage level detected by the voltage level detector. The voltage level detector detects the voltage level of the signal wire during the transition period.

Abstract: An oscillator is disclosed. The oscillator comprises a cycle controller and a re-cycle delay line module. The cycle controller generates a cycle control signal. The re-cycle delay line module produces a periodic signal. The re-cycling delay line module performs a re-cycling operation. The number of re-cycling in the re-cycling operation is determined based on the cycle control signal.

Abstract: Waveform errors between multiphase PWM signals caused by external synchronization signals is solved by providing a capture register in a master time base circuit. The capture register is triggered by the external sync signal so as to “capture” the value of the master time base counter at the occurrence of the rising edge of the external sync signal. This captured counter value is then provided to the local time bases of each of the phase PMW signal generators as the effective PWM period instead of locally stored PWM period values of each PWM signal generator. The captured time base value provided to the individual PWM generator time bases insures that the individual PWM generators remain properly synchronized to the master time base throughout the PWM cycles of all of the phases.

Abstract: A consumption current balance circuit reduces the layout area and suppresses the deterioration of accuracy of a delay time caused by a temperature variation due to a power variation of a delay circuit itself or caused by a load variation of a power supply. The consumption current balance circuit includes a delay circuit for giving a delay time to a timing pulse signal, a compensation circuit for interpolating the consumption current of the delay circuit, a ring oscillator provided in the same power supply area as the delay circuit; an output period counter for measuring the output period of the ring oscillator; and a heater circuit current amount adjusting circuit for adjusting the current amount of the heater circuit to minimize the difference in the output period between the stand-by state and the active state of the ring oscillator.

Abstract: In a device for generating a clock signal having a desired phase from input multi-phase clock signals, an intermediate clock generator generates, by using one of the input multi-phase clock signals as a reference clock signal, multi-phase intermediate clock signals in which one cycle is equal to a plurality of cycles of the reference clock signal. A first phase selector selects one of the multi-phase intermediate clock signals. A second phase selector selects one of the multi-phase clock signals. A latch circuit latches the intermediate clock signal selected by the first phase selector with the clock signal selected by the second phase selector.

Abstract: A data receiver system. The system includes a clock generator configured to output a reference clock and circuitry configured to measure a direction of a phase difference between an input data stream and the reference clock. The circuitry is further configured to increment a counter if the phase difference is in a first direction, decrement the counter if the phase difference is in a direction opposite to the first direction, and convey a phase correction signal to the clock generator if an output value of the counter meets or exceeds a threshold. The clock generator is configured to adjust the phase of the reference clock in response to receiving the phase correction signal.

Abstract: In a semiconductor memory device, a reference delay section has a first delay value and delays a first signal by a reference delay value obtained from the first delay value and an adjustment value while changing the adjustment value, and fixes the adjustment value when the first signal and the delayed first signal meet a predetermined condition. A delay section has a second delay value and generates an output signal based on a summation of the fixed adjustment value and the second delay value, and a set multiplication value in response to a trigger signal such that the output signal in an active state for a period corresponding to the set multiplication value.

Abstract: An apparatus comprising an oscillator circuit, a control circuit, a counter circuit and a detector circuit. The oscillator circuit may be configured to generate an output signal oscillating at a particular frequency in response to a control signal. The control circuit may be configured to generate the control signal in response to a first error signal and a second error signal. The counter circuit may be configured to generate the first error signal in response to the output signal and an input signal. The detector circuit may be configured to generate the second error signal in response to the output signal and the input signal.

Abstract: A timing generator that needs no analog circuit for adding jitters and allows the circuit scale and power consumption to be reduced.

Abstract: The present invention generates an output clock signal CLKreq having a frequency freq between the frequency fref/A of a divided clock signal CKL1 and the frequency fref/(A+1) of a divided clock signal CLK2. A clock divider circuit selectively generates divided clock signals CLK1, CLK2. A discrete value correction circuit controls the clock divider circuit so as to repeat C times the process of generating the clock signal CLK2 once and the clock signal CLK1 (Q?1) times and then to generate the clock signal CLK1 R times if C<D and so as to repeat D times the process of generating the clock signal CLK1 once and the clock signal CLK2 (Q?1) times and then to generate the clock signal CLK2 R times if C>D. A, B, and C are natural numbers satisfying freq=fref/(A+C/B). In D=B?C, Q is a quotient of B/C if C<D or a quotient of B/D if C>D.

Abstract: The signal-to-noise ratio for a digital conversion circuit is improved by taking a source signal and generating N signals that are each phase-shifted relative to each other, thereby generating N phase-shifted signals. Each of the N signals has a frequency that is a fraction of a frequency of the source signal. The source signal is input to a dividing circuit to generate the N signals. The source signal is generated by a signal source, such as an oscillator. Each of the N signals is hard-limited and processed through a detection circuit. The detection circuit can be a frequency detection circuit configured to determine the frequency of the source signal and to output a corresponding digital word, or a phase detection circuit configured to determine a phase of the source signal and to output a corresponding digital word.

Abstract: A digital DLL circuit includes: a register configured to hold a delay target value; an oscillator; a first counter configured to count an external reference clock or an oscillation output from the oscillator; a second counter configured to count the oscillation output from the oscillator or the external reference clock in every measurement cycle determined by the first counter; and a digitally-controlled variable delay circuit. The DLL circuit further includes a control circuit configured to control the reset and activation of the first counter and the second counter, and control the stop of the first and second counters according to need, based on a count value of the first counter, the control circuit subjecting a count value of the second counter and the delay target value of the register to a digital arithmetic operation, and supplying the variable delay circuit with a result of the arithmetic operation as a delay control value.

Abstract: A synchronous memory device having an output driver controller, comprises a DLL circuit for receiving an external clock and outputting an internal clock; an output driver for outputting data in synchronism with the internal clock; and an output driver controller for controlling operation of the output driver, wherein the output driver controller makes the output driver active after receiving from the DLL circuit a control signal indicating that the internal clock is locked and is in a stabilized state.

Abstract: A digital DLL circuit includes: a first register configured to hold a delay specifying value to specify a delay; a second register configured to specify a correction value for a gate delay inside an LSI; a digitally-controlled variable delay circuit; and a control circuit configured to produce a delay control value to implement control so that a delay by the variable delay circuit is kept at the delay specifying value of the first register. The digital DLL circuit further includes an adder circuit configured to add a gate delay correction value held by the second register to the delay control value output from the control circuit, and output a resultant value to a control input of the variable delay circuit.

Abstract: A clock recovery system includes a sampler that is configured to sample an input data signal in synchronization with a modulated clock signal to generate a sample of the input data signal. A phase comparator is configured to compute a position of a transition edge of the input data signal using the sample data signal, and to compare the computed position with a position of an edge of the modulated clock signal to generate a comparison result. An edge counter is configured to count transition edges of the sample data signal. A controller is configured to generate first and second control signals based on the comparison result and the count of the transition edges. A clock phase modulator is configured to generate the modulated clock signal by adjusting a phase of an input clock signal responsive to the first and second control signals, such that the phase is increased in response to the first control signal and reduced in response to the second control signal.

Abstract: A Delay Locked Loop (DLL) driver control circuit is capable of reducing an amount of current consumption by preventing the output of unnecessary clocks. The DLL driver control circuit includes a DLL driver for driving a DLL clock and a DLL driver controller for generating a control signal to control an operation of the DLL driver in response to a signal having information associated with an active mode. The DLL driver controller is provided with a counter for counting the DLL clock to produce a count a setting value having a plurality of bits and generating an activated equal signal if the two values are the same, and an SR latch for accepting the equal signal and the signal having the information associated with the active mode to provide the control signal.

Abstract: A method of synchronizing counters in two different clock domains within a memory device is comprised of generating a start signal for initiating production of a running count of clock pulses of a read clock signal in a first counter downstream of a locked loop and delaying the input of the start signal to a second counter upstream of the locked loop to delay the initiation of a running count of control clock pulses by an amount equal to a predetermined delay. Another disclosed method is for controlling the output of data from a memory device comprising deriving from an external clock signal a control clock for operating an array of storage cells and a read clock, both the control clock and the read clock being comprised of clock pulses. A start signal is generated for initiating production of a running count of the read clock pulses in a first counter. The start signal may be produced when a locked loop achieves a lock between the read clock and the control clock.

Abstract: In some embodiments, a chip includes clock generation circuitry to create a clock signal, and reference signal oscillator circuitry to produce a reference signal with a higher frequency than the clock signal. The chip includes a counter to change a count value in response to changes in the reference signal; and count logic circuitry to cause count storage circuitry to read the count value in response to at least some changes in the clock signal and to make at least some of the values in the count storage circuitry related to a duty cycle of the clock signal available to an external tester. Other embodiments are described and claimed.

Abstract: A divider apparatus for use within a phase-locked loop having an output terminal at which an output frequency is produced. The apparatus includes a prescalar circuit configured to produce a prescaled signal by dividing the output frequency in response to a mode select signal. A first programmable counter is disposed to receive the prescaled signal and to produce the mode select signal. In addition, a second programmable counter is disposed to receive the prescaled signal and to produce a divided signal utilized by the phase-locked loop. The apparatus further includes a control circuit connected to the first programmable counter and to the second programmable counter, the control circuit providing a first resynchronization signal to the first programmable counter and a second resynchronization signal to the second programmable counter.

Abstract: An on-chip jitter measurement circuit and corresponding method are provided for receiving a reference clock and a signal of interest, including a latch for comparing the arrival time of the signal of interest to the reference clock, a delay chain in signal communication with the reference clock for varying the arrival time of the reference clock, the delay chain having a first stage, a middle stage, and a last stage, a voltage controller in signal communication with the middle stage of the delay chain for controlling the delay of the arrival time of the reference clock while permitting the first and last stages of the delay chain to retain a full voltage swing independent of the delay.

Abstract: According to the present invention, there is provided a semiconductor device including: a phase locked loop circuit having, a phase frequency detector which receives a reference signal and a frequency-divided signal, and outputs a phase difference detection signal by performing phase comparison, a charge pump which receives the phase difference detection signal and outputs a charge pump signal by converting a voltage change into a current change, a loop filter which receives the charge pump signal, and outputs a control voltage by passing components having frequencies not more than a predetermined frequency, a voltage controlled oscillator which outputs a frequency signal having a frequency based on the control voltage, and a frequency divider which receives the frequency signal, and outputs the frequency-divided signal by dividing the frequency; a mask signal generator which generates a mask signal masking a timing at which the phase frequency detector compares phases of the frequency-divided signal and the

Abstract: A spread spectrum clock generator is disclosed. The spread spectrum clock generator (SSCG) bases on the structure of the phase-lock loop. The SSCG uses the voltage control oscillator with multi-phase output function for outputting clock signals of different phases. The clock signals of different phases are selectively fed back to the phase frequency detector. In this way, the frequency of the output signal is changed, which achieves spreading spectrum.

Abstract: A read latency control circuit is described having a clock synchronization circuit and a read latency control circuit. The clock synchronization circuit includes an adjustable delay line to generate an output clock signal whose phase is synchronized with the phase of the input clock signal. The read latency control circuit captures a read command signal relative to the timing of the input clock signal and outputs the read command signal relative to the timing of the output clock signal such that the read command signal is outputted indicative of a specified read latency.

Abstract: A phase locked loop (PLL) is provided. In one implementation, the PLL includes a feedback loop having a frequency multiplier and an integer divider to generate a divided signal. The PLL includes a re-sampling circuit operable to re-sample one or more digital pulses of the divided signal using one or more phase signals if a multiplication factor of the frequency multiplier does not divide evenly into the integer divisor.

Abstract: The present invention, generally speaking, achieves noise spreading within a PLL using a dual-modulus prescaler by interleaving the division moduli. Within a given cycle, “ones” and “tens” are not all counted consecutively. Instead, ones and tens are interleaved. In one embodiment of the invention, the R count is doubled and the output of the R counter is toggled between high and low states. (The Q counter may remain unmodified.) In another embodiment of the invention, ones and tens are interleaved in accordance with a ratio q:r. By so interleaving the modulus, the effect is to spread the noise resulting from the output signal of the dual-modulus prescaler over a wider frequency range. The prescaler noise level is greatly reduced, particularly within the frequency band of the reference frequency.

Abstract: A trimming system for determining a trim solution for a semiconductor device includes an internal value generating circuit for generating an internal value based upon a counter value. The relationship between the internal delay value and an external reference is compared to determine if the counter value is a possible trim solution, while predetermined counter values are excluded as a trim solution.

Abstract: A data output strobe signal generating circuit includes a duty cycle correcting unit that corrects the duty ratio of an input clock in response to a control signal to generate a corrected clock. A data output strobe signal generating unit receives the corrected clock and generates a data output strobe signal. A duty cycle control unit receives the data output strobe signal and outputs the control signal.

Abstract: The disclosed embodiments relate to circuits that produce synchronized output signals. More specifically, there is provided a synchronization circuit adapted to receive an input signal, the synchronization circuit comprising a delay monitor adapted to produce a delayed input signal, a counter adapted to determine a difference between the input signal and the delayed input signal and produce a coarse timing signal in response thereto, a circuit adapted to produce a fine timing signal based on the input signal, and a circuit adapted to combine the coarse timing signal and the fine timing signal to produce an output signal.

Abstract: A tunable delay line is calibrated to maintain the delay of the delay line at a desired value or within a desired range of values. In some aspects a signal is passed through a delay line multiple times so that the cumulative delay of the signal through the delay line (e.g., as indicated by a count) may be calculated over a period of time. The count is compared with an expected count and, based on this comparison, the delay of the delay line is adjusted as necessary. In some aspects the signal may comprise a digital signal. In some aspects a delay through a delay line may be calculated based on analysis of amplitude changes in a signal caused by a phase shift imparted on the signal by the delay line. In some aspects a delay line is incorporated into a transmitted reference system to generate and/or process transmitted reference signals.

Abstract: A counter control signal generating circuit is disclosed.

Abstract: A frequency-locking device including a digitally-controlled oscillator (DCO) and a comparing unit is disclosed. The DCO is used for generating an output frequency signal. The comparing unit receives a Keep Alive signal from a universal serial bus (USB) and the output frequency signal, and compares the Keep Alive signal with the output frequency signal to generate a calibration signal. Then, the DCO adjusts the frequency of the output frequency signal according to the calibration signal to meet the USB specification for data communication.

Abstract: A circuit provides a programmable phase shift feature, where the phase shift is programmably selectable by a user. This circuitry may be incorporated in a programmable logic device (PLD) or field programmable gate array (FPGA) to provide additional programmability features. The programmable phase shift circuitry may be implemented within a phase locked loop (PLL) or delay locked loop (DLL) circuit. In an implementation, the programmable phase shift circuitry is implemented using two programmable counters.

Abstract: A method of synchronizing counters in two different clock domains within a memory device is comprised of generating a start signal for initiating production of a running count of clock pulses of a read clock signal in a first counter downstream of a locked loop and delaying the input of the start signal to a second counter upstream of the locked loop to delay the initiation of a running count of control clock pulses by an amount equal to a predetermined delay. Another disclosed method is for controlling the output of data from a memory device comprising deriving from an external clock signal a control clock for operating an array of storage cells and a read clock, both the control clock and the read clock being comprised of clock pulses. A start signal is generated for initiating production of a running count of the read clock pulses in a first counter. The start signal may be produced when a locked loop achieves a lock between the read clock and the control clock.

Abstract: A method of synchronizing timers in a wireless network is described. According to some embodiments, a master timer is sampled at the start time of a first beacon in a first data object and the sampled master timer value is broadcast in a second beacon of a second data object. A slave timer is sampled at the start of the second beacon in the second data object and a value representing the duration of the first data object is subtracted from the sampled slave timer value to determine an updated sampled slave timer value. According to some variations, a difference is determined between the sampled master timer value and the updated sampled slave timer value. The method then uses the difference to synchronize the slave timer to the master timer and to other slaver timers synchronized to the same master timer.

Abstract: A system and method are used to allow high speed communication between a chip and an external device. The system and method include a PLL with multiple phased outputs configured to be controlled digitally, a deskew PLL configured to align a clock of controller circuitry to interface circuitry, and a phase interpolated voltage controlled delay line configured to phase shift incoming signals. Analog design techniques of phase interpolation accurately position clocks and strobe signals that are required for high speed interfaces. The high speed interface is for transmitting and receiving signals from the external device, for example, a DDR DRAM.