Abstract: A semiconductor memory device has a DLL circuit capable of suppressing EMI without distorting a DLL clock required in high-speed operation. The semiconductor memory device includes a delay locked loop (DLL) circuit configured to be responsive to a system clock to output a DLL clock having a phase that is changed when electromagnetic interference (EMI) is detected, for the DLL clock to have frequencies within a delay locking range, and a data output circuit configured to output data in synchronization with the DLL clock.

Abstract: A variable delay circuit successively delays an input clock to generate a plurality of delayed clocks having different phases. A phase comparison circuit receives a first reference clock, which is either one of the delayed clocks or the input clock, and a second reference clock, which is one of the delayed clocks and whose phase lags behind that of the first reference clock, specifies a validated interval for the second reference clock, and compares the phases of the first and second reference clocks according to voltage levels of the first and second reference clocks only during the validated interval. A delay control circuit controls a delay time in the variable delay circuit according to a result of the comparison obtained by the phase comparison circuit.

Abstract: An adjustable buffer including a series of P-channel devices having current paths coupled between a first voltage supply and at least one output node, and a series of N-channel devices having current paths coupled between the output node and a second voltage supply. The control electrodes of the P- and N-channel devices are coupled to a selected one of an input node and a corresponding voltage supply collectively forming first and second sets of selectable connections. The first and second sets of selectable connections are made to adjust delay from the input node to the output node. The selectable connections may be defined in an integrated circuit mask or may be electronic switches. The P- and N-channel devices may be in a balanced configuration or an imbalanced configuration. The P- and N-channel devices may form an inverting buffer or a non-inverting buffer.

Abstract: A delay locked loop circuit includes a clock buffering block to generate first and second internal clocks corresponding to first and second edges of a source clock in response to a clock buffering control signal, respectively, wherein generation of the second internal clock is controlled by a duty correcting operation terminating signal and a delay locking signal, a delay locking block to compare phases of the first and second internal clocks with those of first and second feedback clocks, respectively, to enable the delay locking signal according to a delay locking and delay the first and second internal clocks as many as times corresponding to the comparison results, respectively, thereby outputting first and second delay locking clocks, a duty correcting block to mix phases of the first and second delay locking clocks, and a first signal generating block to generate the duty correcting operation terminating signal.

Abstract: A communication device and method is provided, comprising: a signal modulator/demodulator having a digital signal processor for effecting radio communications; and an application processor (AP) having a central processing unit for controlling a plurality of peripherals, and a memory shared by the modem and the AP. The shared memory is accessed by the AP and the modem via a common bus. The plurality of peripherals include at least one of an image capture module, a display, and a flash memory.

Abstract: A DLL circuit includes a clock selection control unit configured to generate a clock selection signal on the basis of a phase difference between a reference clock and a feedback clock and, after the clock selection signal is generated, to generate an initialization signal. A delay control unit, when the initialization signal is enabled, transfers an initial voltage to be generated by dividing an external power supply voltage to a delay unit as a control voltage, and controls a delay operation of a delay reference clock to be selected on the basis of the clock selection signal.

Abstract: A two-point modulator using a voltage control oscillator includes: a modulation section including a feedback circuit for performing feedback control of a signal outputted from the voltage control oscillator based on an inputted modulated signal, and a feedforward circuit for calibrating the modulated signal and outputting the calibrated modulated signal to the voltage control oscillator; a signal output section for, upon calibration processing, outputting a predetermined reference signal in place of the modulated signal, to the modulation section; and a gain correction section for, in a state where the feedback circuit is in an open loop state, calculating a frequency transition amount of the reference signal outputted from the voltage control oscillator, and correcting a gain used for calibration of the modulated signal performed by the feedforward circuit, based on the calculated frequency transition amount.

Abstract: Some embodiments include a delay line configured to apply a delay to an input signal to provide an output signal; an input circuit configured to provide the input signal based on a first signal, such that the cycle time of the input signal is different from a cycle time of the first signal; an output circuit configured to provide a second signal based on the output signal, the second signal having a cycle time different from a cycle time of the output signal; and a controller configured to adjust the delay to control a timing relationship between the first signal and the second signal. Other embodiments are described and claimed.

Abstract: A feedback loop circuit includes a phase detector and delay circuits. The phase detector generates an output signal based on a delayed periodic signal. The delay circuits are coupled in a delay chain that delays the delayed periodic signal. Each of the delay circuits includes variable delay blocks and fixed delay blocks that are coupled to form at least two delay paths for an input signal through the delay circuit to generate a delayed output signal. Delays of the variable delay blocks in the delay circuits vary based on the output signal of the phase detector. Each of the delay circuits reroutes the input signal through a different one of the delay paths to generate the delayed output signal based on the output signal of the phase detector during operation of the feedback loop circuit.

Abstract: A DLL circuit including a first clock signal dividing block configured to selectively divide a frequency of a reference clock signal according to whether a lock completion signal is enabled, a phase comparing block configured to generate a phase comparison signal by comparing phases of a clock signal transmitted from the first clock signal dividing block with a feedback clock signal, and an operation mode setting block configured to generate the lock completion signal in response to the phase comparison signal is described herein.

Abstract: The semiconductor integrated circuit includes a clock generating section having a digital control signal generating part operable to generate a clock signal and a digital control part. The clock generating section further includes a phase-frequency comparator and a control register. The comparator is supplied with a reference signal CLKin and a feedback signal. The control register is supplied with an output signal of the comparator, and stores two or larger bits of digital control information. The clock generating section further includes a control data storing circuit for previously storing sets of initial set data for lock operations. In response to operation select information, initial set data are stored at upper bit of the control register from the control data storing circuit. Thus, it becomes possible to reduce the number of steps to store control information in a register for digitally controlling the clock signal generating part.

Abstract: A semiconductor memory apparatus having a clock signal generation circuit and a data output circuit is presented. The apparatus includes a delay locked loop (DLL), a phase locked loop (PLL), a frequency discrimination unit, and a data output buffer. The DLL circuit is configured to negatively delay a clock signal to generate a DLL clock signal. The PLL circuit is configured to receive the DLL clock signal to generate a control voltage in response to a frequency of the DLL clock signal and to generate a PLL clock signal of a frequency corresponding to a level of the control voltage. The frequency discrimination unit is configured to discriminate a frequency of the DLL clock signal in accordance with the level of the control voltage to generate a frequency discrimination signal. The data output buffer is configured to receive the DLL clock signal or the PLL clock signal to buffer output data signals.

Abstract: Various embodiments of a semiconductor integrated circuit. According to one exemplary embodiment, a semiconductor integrated circuit includes a multi-phase clock generator that is configured to generate a multi-phase internal clock; a first edge combining unit that is configured to generate a first output clock having a first frequency by combining rising edges of clocks included in the internal clock, and transmit the first output clock to a first port; and a second edge combining unit that is configured to generate a second output clock having a second frequency by combining rising edges of clocks included in the internal clock, and transmit the output clock to a second port.

Abstract: A method and circuit for static phase error measurement includes a reference clock delay chain having a selectable number of delay elements. A number of the delay elements are enabled in accordance with a select length signal to delay a reference clock signal. A feedback signal delay chain also has a selectable number of delay elements. A number of the delay elements are enabled in accordance with a select length signal to delay a feedback signal. A latch tests phase alignment between the delayed reference clock signal and the delayed feedback signal and outputs a measurement of static phase error.

Abstract: A DLL circuit includes a delay line that generates an internal clock signal by delaying an external clock signal CLK, a counter circuit that sets a delay amount of the delay line, a phase detecting circuit that generates a phase determination signal based on a phase of the external clock signal, and an antialiasing circuit that prohibits the counter circuit to update a count value based on the phase determination signal, in response to a fact that a jitter component included in the external clock signal is equal to or higher than a predetermined frequency. With this configuration, a problem that the internal clock signal is continuously controlled to a wrong direction due to malfunction of aliasing does not occur.

Abstract: A delay locked loop (DLL) of a semiconductor device has a relatively small area and low current consumption while having a function of correcting a duty ratio. The semiconductor device includes a split unit configured to receive and split a reference clock to output a first clock corresponding to a first edge of the reference clock and a second clock corresponding to a second edge, a voltage generation unit configured to generate a first voltage corresponding to a duty ratio of the first clock and a second voltage corresponding to a duty ratio of the second clock, a voltage comparison unit configured to compare levels of the first and second voltages with each other, and a clock delay unit configured to receive one of the first and second clocks to delay the received clock of which delay amount is determined in response to an output signal of the voltage comparison unit.

Abstract: Locked loops, delay lines and methods for delaying signals are disclosed, such as a delay line and delay lock loop using the delay line includes a series of delay stages, each of which consists of a single inverting delay device. The inputs and outputs of a selected stage are applied to a phase inverter that inverts one of the signals and applies it to a first input of a phase mixer with the same delay that the other signal is applied to a second input of the phase inverter. The delay of the signals from the selected delay element are delayed from each other by a coarse delay interval, and the phase mixer interpolates within the coarse delay interval by fine delay intervals. A phase detector compares the timing of a signal generated by the phase interpolator to the timing of a reference clock signal applied to the delay line to determine the selected delay stage and a phase interpolation value.

Abstract: A phase splitter using digital delay locked loop (DLL) to receive complementary input clock signals to generate a plurality of output signals having different phase shifts. When the DLL is locked, the delay resolution of the phase splitter is equal to two delay stages of the DLL.

Abstract: A delay locked loop circuit includes a delay locking block configured to delay an input clock and output the delayed input clock as an internal clock to compensate a skew of an external clock and the internal clock, a pulse generating block configured to sequentially output a plurality of pulse signals that control an operation of the delay locking block and enable one of the plurality of pulse signals in response to a detection signal, wherein the plurality of pulse signals is shifted by being synchronized with the input clock, and a pulse detecting block configured to output the detection signal in case all of the plurality of pulse signals are disabled.

Abstract: A delay locked loop (DLL) of a semiconductor device has a relatively small area and low current consumption while having a function of correcting a duty ratio. The semiconductor device includes a split unit configured to receive and split a reference clock to output a first clock corresponding to a first edge of the reference clock and a second clock corresponding to a second edge, a voltage generation unit configured to generate a first voltage corresponding to a duty ratio of the first clock and a second voltage corresponding to a duty ratio of the second clock, a voltage comparison unit configured to compare levels of the first and second voltages with each other, and a clock delay unit configured to receive one of the first and second clocks to delay the received clock of which delay amount is determined in response to an output signal of the voltage comparison unit.

Abstract: A delay locked loop (DLL) of a semiconductor device has a relatively small area and low current consumption while having a function of correcting a duty ratio. The semiconductor device includes a split unit configured to receive and split a reference clock to output a first clock corresponding to a first edge of the reference clock and a second clock corresponding to a second edge, a voltage generation unit configured to generate a first voltage corresponding to a duty ratio of the first clock and a second voltage corresponding to a duty ratio of the second clock, a voltage comparison unit configured to compare levels of the first and second voltages with each other, and a clock delay unit configured to receive one of the first and second clocks to delay the received clock of which delay amount is determined in response to an output signal of the voltage comparison unit.

Abstract: A digital phase-locked loop (DPLL) supporting two-point modulation with adaptive delay matching is described. The DPLL includes highpass and lowpass modulation paths that support wideband and narrowband modulation, respectively, of the frequency and/or phase of an oscillator. The DPLL can adaptively adjust the delay of one modulation path to match the delay of the other modulation path. In one design, the DPLL includes an adaptive delay unit that provides a variable delay for one of the two modulation paths. Within the adaptive delay unit, a delay computation unit determines the variable delay based on a modulating signal applied to the two modulation paths and a phase error signal in the DPLL. An interpolator provides a fractional portion of the variable delay, and a programmable delay unit provides an integer portion of the variable delay.

Abstract: A power-down mode control apparatus includes an internal power-down control block configured to receive a locking completion signal and to generate an internal power-down signal, which is toggled for a predetermined time; a noise check block configured to check occurrence/non-occurrence of noise on the basis of a phase detection signal and to generate a plurality of power-down selection signals in response to the locking completion signal and the internal power-down signal; and a power-down enter control block configured to generate a plurality of power-down enter signals, which instruct individual circuits to enter a power-down mode in response to a reference clock signal, the plurality of power-down selection signals, a power-down mode signal, and the internal power-down signal.

Abstract: A delay locked loop (DLL) architecture includes a time cycle suppressor circuit suitable for use with synchronous integrated circuits containing a clock generator. Utilization of the improved delay locked loop architecture with a time cycle suppressor circuit disclosed herein enables reduction in the lock time of the synchronous circuit.

Abstract: A method for extending a tracking range of a PLL includes the steps of: establishing an initial tracking window of the PLL, the tracking window having a first width associated therewith; and dynamically adjusting the tracking window of the PLL within an extended tracking range when a frequency of an input signal supplied to the PLL is outside of the tracking window, the extended tracking range having a second width associated therewith which is greater than the first width.

Abstract: A method and apparatus are disclosed for generating phase controlled data, based on a roaming tap interpolator. The present invention recognizes that roaming tap interpolators have inherent nonlinearities and discontinuities at the boundaries of each interpolation region. A roaming tap interpolator is disclosed that shifts the interpolation curve in time in order to avoid the undesired artifacts in the interpolation curve. A roaming tap interpolator generally comprises a plurality of delay elements that delays a first signal to generate a plurality of interpolation regions each having an associated phase; a multiplexer to select one or more of the interpolation regions; and an interpolator to process the selected one or more of the interpolation regions to generate a second signal.

Abstract: A delay locked loop circuit includes a delay locking unit configured to output an internal clock by delaying a reference clock as much as a first delay amount in response to a phase comparison result of comparing a phase of the reference clock with a phase of a feedback clock that is generated based on delay modeling of a semiconductor memory device, and a noise sensor configured to control variation of the first delay amount caused by an external noise to be less than a second delay amount after locking the internal clock.

Abstract: The semiconductor integrated circuit includes a clock generating section having a digital control signal generating part operable to generate a clock signal and a digital control part. The clock generating section further includes a phase-frequency comparator and a control register. The comparator is supplied with a reference signal CLKin and a feedback signal. The control register is supplied with an output signal of the comparator, and stores two or larger bits of digital control information. The clock generating section further includes a control data storing circuit for previously storing sets of initial set data for lock operations. In response to operation select information, initial set data are stored at upper bit of the control register from the control data storing circuit. Thus, it becomes possible to reduce the number of steps to store control information in a register for digitally controlling the clock signal generating part.

Abstract: A locking state detector includes a phase comparing unit configured to compare a reference clock signal and a feedback clock signal to generate a first phase difference distinction signal to distinguish a first phase difference range, and a second phase difference distinction signal to distinguish a second phase difference range wider than the first phase difference range, and a locking state setting unit configured to generate a locking state signal in response to the first phase difference distinction signal and the second phase difference distinction signal.

Abstract: A DLL circuit includes a coarse delay adjustment circuit and a fine delay adjustment circuit, which further includes a first fine delay circuit and a second fine delay circuit serving as an interpolation circuit. The coarse delay adjustment circuit delays a reference clock signal by a plurality of delay stages so as to provide the first fine delay circuit with two phase signals having the phase difference of two delay stages, which are then converted into two delay signals having the phase difference of one delay stage. The delay signals are subjected to interpolation, thus producing an output clock signal. Due to a reduction of the phase difference in the first fine delay circuit, it is possible to reduce the minimum operation cycle of the interpolation circuit and to thereby increase the maximum operation frequency of the DLL circuit.

Abstract: A methodology is disclosed that enables the delay stages of an analog delay locked loop (DLL) or phase locked loop (PLL) to be programmed according to the operating condition, which may depend on the frequency of the input reference clock. The resulting optimized delay stages allow for a broad frequency range of operation, fast locking time over a wide range of input clock frequencies, and a lower current consumption at high clock frequencies. Better performance is achieved by allowing the number of analog delay stages active during a given operation to be flexibly set. The deactivation or turning off of unused delay stages conserves power at higher frequencies. The high frequency range of operation is increased by using a flexible number of delay stages for various input clock frequencies. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

Abstract: A delay circuit includes a delay line unit including a plurality of delay units configured to generate a plurality of delay input clocks by delaying an input clock by a unit delay amount in response to at least one delay control signal; and a signal selection unit configured to selectively output at least one of the plurality of delay input clocks in response to the delay control signal.

Abstract: A DLL (delay locked loop) circuit includes a first variable delay circuit, a pair of second variable delay circuits and a first synthesis circuit. The first variable delay circuit outputs signals of different delayed time values from each of first and second clock transitions. The pair of second variable delay circuits receive the signals from the first variable delay circuit, and the first synthesis circuit synthesizes output signals of the pair of second variable delay circuits to output the resulting synthesized signal. Each of the pair of second variable delay circuits includes a pair one-shot pulse generating circuits that generate one-shot pulses from the signals from the first variable delay circuit, a pair latch circuits, and a second synthesis circuit. The second synthesis circuit receives the set outputs of the latch circuits to output a signal which is a synthesis at a preset synthesis ratio.

Abstract: A semiconductor integrated circuit includes a DLL controlling block configured to enable or disable an update enable signal by detecting a change in a voltage level of a phase detecting signal during a predetermined time when an operation enable signal and a threshold phase difference detecting signal are enabled, and a delay locked loop (DLL) circuit configured to generate an output clock signal by delaying and driving the reference clock signal and to control a frequency of a change in the delay amount of the reference clock signal in response to the update enable signal.

Abstract: A delay locked loop (DLL) apparatus includes a first delay unit converting a reference clock into a rising clock. A second delay unit converts the reference clock into a falling clock, and a replica delay unit replica-delays the rising clock. A first phase detector compares the phases of the reference clock and the delayed rising clock to output a first detection signal corresponding to the compared phases. A controller synchronizes the rising edge of the rising clock with the rising edge of the reference clock according to the first detection signal of the first phase detector. A second phase detector compares the phases of the synchronized rising clock and the synchronization clock to output a second detection signal corresponding to the compared phases. The DLL apparatus compensates for a skew between an external clock and data and between external and internal clocks by employing a single replica delay unit.

Abstract: A delay locked loop circuit includes a delay locking unit configured to output a first internal clock and a second internal clock, a rising edge of which is synchronized with that of the first internal clock by delaying a compensated external clock for compensating a skew of a semiconductor memory device; a duty ratio compensation unit configured to generate the compensated external clock by compensating a duty ratio of an external clock of the semiconductor memory device and to compensate duty ratios of the first and second internal clocks; and a clock control unit configured to control an activation state of the second internal clock after the duty ratio compensation of the external clock.

Abstract: Clock circuits, memories and methods for generating a clock signal are described. One such clock circuit includes a delay locked loop (DLL) configured to receive a reference clock signal and generate an output clock signal having an adjustable phase relationship relative to the reference clock signal, and further includes a clock jitter feedback circuit coupled to a clock tree and the DLL. The clock jitter feedback circuit is configured to synchronize a clock jitter feedback signal and a DLL feedback signal that is based on the output clock signal. The clock jitter feedback circuit is further configured to provide the clock jitter feedback signal to the DLL for synchronization with a buffered reference clock signal. The clock jitter feedback signal is based on and generated in response to receiving a distributed output clock signal from the clock tree circuit and the buffered reference signal is based on the reference clock signal.

Abstract: A system and method for performing output clock phase smoothing. A phase smoothing circuit is described and includes a numerically-controlled oscillator (NCO) configured to produce a plurality of NCO clock pulses at a selectable frequency that is based on an input clock. Edges of the plurality of NCO clock pulses are aligned to edges of the input clock. A phase error calculation module is coupled to the NCO and is configured to generate a corresponding phase error for each of the plurality of NCO clock pulses. A clock phase selectable delay is coupled to the phase error calculation module and is configured to adjust each of the plurality of NCO clock pulses according to the corresponding phase error to generate an output clock at the selectable frequency that are phase-adjusted to more closely match an ideal output clock phase. Edges of the output clock need not necessarily align to the edges of the input clock.

Abstract: A delay locked loop (DLL) includes a delay-locking unit configured to generate first and second delay clocks corresponding to first and second clock edges of a reference clock for achieving a delay-locking; a phase detection unit configured to detect a phase difference between the first and second delay clocks to output a weight selection signal; a weight storage unit configured to store the weight selection signal obtained during a predetermined period from a point of time when the first and second delay clocks are delay locked; and a phase mixing unit configured to mix phases of the first and second delay clocks to output a DLL clock by applying a weight corresponding to the stored weight selection signal in the weight storage unit.

Abstract: A DLL circuit includes an input circuit generating a synchronization reference signal, a first delay unit delaying the synchronization reference signal to generate a plurality of delayed synchronization reference signals and selecting one of the delayed synchronization reference signals, a timing offset circuit adjusting a synchronization position of the delayed synchronization reference signal to generate a signal to be synchronized, a phase comparison circuit comparing phase of the synchronization reference signal with that of the signal to be synchronized, a first control circuit selecting an output signal of the first delay unit, a second delay unit delaying the synchronization reference signal or the signal to be synchronized to generate a plurality of delayed signals, a configuration information memory storing configuration information, and a second control circuit selecting an output signal of the second delay unit if the comparison result of the phase comparison circuit is within a predetermined range

Abstract: A DLL circuit includes a multiphase clock signal generating unit configured to produce a plurality of multiphase clock signals by delaying a reference clock signal for a unit delay time and to produce an enable signal that is enabled when one of the plurality of the multiphase clock signals synchronizes with the reference clock signal at a frequency, and a multiphase clock signal selecting unit configured to delay one of the plurality of the multiphase clock signals for a predetermined time in response to a first control signal, to compare a phase of a delayed multiphase clock signal with a phase of the reference clock signal, and to output one of the plurality of the multiphase clock signals as a delayed clock signal, wherein a phase of the delayed clock signal synchronizes with the phase of the reference clock signal when the enable signal is enabled.

Abstract: A delay locked loop (DLL) circuit includes a duty cycle correcting unit configured to correct a duty cycle of a reference clock signal in response to a duty cycle correction signal and generate a correction clock signal. A feedback loop of the DLL circuit performs a delay lock operation on the correction clock signal and generates an output clock signal. A first duty cycle detecting unit detects a duty cycle of the correction clock signal and generates a first detection signal and a second duty cycle detecting unit detects a duty cycle of the output clock signal and generates a second detection signal. Finally, a duty cycle control unit generates the duty cycle correction signal in response to the first detection signal and the second detection signal to perform the duty cycle correction.

Abstract: A delay locked loop (DLL) circuit has a first delay line that delays a received external clock signal for a fine delay time and then outputs a first internal clock signal; a duty cycle correction unit that corrects a duty cycle of the first internal clock signal and then outputs a second clock signal; a second delay line that delays the second clock signal for a coarse delay time and then outputs a second internal clock signal; and a phase detection and control unit that detects the difference between the phases of the external clock signal and the fed back second internal clock signal, and controls the fine delay time and the coarse delay time. The DLL circuit performs coarse locking and fine locking by using different type delay cells, and thus consumes a small amount of power and robustly withstands jitter and variation in PVT variables.

Abstract: A delay locked loop includes a DLL hold control unit that receives a first control signal and outputs a DLL hold control signal, and a DLL block that receives the DLL hold control signal and generates a DLL clock.

Abstract: Embodiment of the present invention relate to a method for receiving a first signal, determining a first characteristic of the first signal, the characteristic being a time based characteristic, receiving a second signal and processing the second signal through a predetermined range of delay elements, an initial minimum number of delay elements in the predetermined range being adjustable, the processed second signal having a second characteristic substantially corresponding to the first characteristic of the first signal.

Abstract: A delay locked loop can remove a jitter component that inevitably occurs due to feedback latency in the conventional DLL. That is, the present invention has benefit of removing the jitter component by controlling the delay lines based on the predicted data. The delay locked loop includes a pattern detecting unit for generating and storing a noise pattern by detecting inputted noise data, a pre-delay control unit for determining a delay amount depending on the output of the pattern detecting unit, and a pre-delay line for delaying an internal clock depending on the delay amount that is determined by the pre-delay control means.

Abstract: A data driver circuit and a delay-locked loop (DLL) are provided. The data driver circuit and DLL can operate normally in spite of errors, etc., caused when an analog data signal is applied to a display panel. The DLL, which receives a first clock signal and outputs a second clock signal, includes a phase detector for outputting a phase difference signal according to the first clock signal, the second clock signal and at least one delay signal, and a delay line for generating the second clock signal and the delay signal by delaying the first clock signal. Here, the phase difference signal has a value corresponding to a phase difference between the first clock signal and the second clock signal, according to the first clock signal or the second clock signal, and a value corresponding to a case in which there is no phase difference according to the delay signal, and a first delay that is a delay of the second clock signal with respect to the first clock signal changes according to the phase difference signal.

Abstract: Clock synchronization and skew adjustment circuits that utilize differing unit delay elements in their delay lines in either a graduated or a stepped unit time delay arrangement are for synchronizing with a clock signal. These graduated or a stepped unit time delays allow reduction in the number of the fine unit delay elements of the delay lines by placing a fine delay element granularity at the most critical timings to sense and adjust for the portion of the clock signal time period that are high speed or critical.

Abstract: A clock generation circuit, which includes a reference clock delay circuit including a number M of delay units connected in series, and configured to delay a reference clock by L cycles; and an oscillation circuit including a number N of delay units connected in series, and configured to generate an oscillation clock according to the following Equation, tOS = 2 ? ? N × DD = 2 ? ? N × L × tCLK M where each delay unit is configured to delay an input signal by a reference delay amount DD, tOS is a period of the oscillation clock, and tCLK is the reference clock.

Abstract: A delay locked loop circuit and a method for controlling the same including a delay locked loop (DLL) circuit for receiving an external clock signal and generating an internal clock signal synchronized to the external clock signal includes at least two delay chains having different types of delay cells for delaying the external clock signal. Thus, the layout area and power consumption can be reduced, and logic failures can be prevented or minimized by replacement or compensation of the main delay cells.