Abstract: A method and apparatus for reducing jitter in a delay line and trim unit is described. The trim unit includes a plurality of delay elements in parallel. At least one of the plurality of delay elements is controllable between on and off states. At least one of the plurality of delay elements includes at least one filter element to filter local supply noise. At least one of the plurality of delay elements includes a plurality of delay circuits having at least one gated delay circuit to control propagation of a clock signal through the plurality of delay circuits. The plurality of delay elements are configured to maintain an overall propagation delay without adding additional circuitry by sizing at least one delay circuit to provide longer propagation delay and sizing the other delay circuits to provide smaller propagation delay. The plurality of delay circuits are sized and arranged to minimize jitter.

Abstract: Variable delay circuits and methods for delaying a waveform by an adjustable time delay are disclosed herein. One such variable delay circuit comprises a delay range limitation circuit having a first differential input, a first differential output, and a second differential output. The first differential input is configured to receive an input waveform. The first differential output is configured to output the waveform with a maximum delay, and the second differential output is configured to output the waveform with a minimum delay. The variable delay circuit further comprises a delay mixing circuit having second and third differential inputs, first and second control inputs, and a third differential output. The second differential input is connected to the first differential output. The third differential input is connected to the second differential output. The first and second control inputs are configured to receive control voltages V1 and V2, which are related to a selected time delay.

Abstract: A delay circuit includes a phase vernier having a plurality of logic components. Each logic component includes a selectable injection input capable of adjusting a phase of an input to the phase vernier.

Abstract: Systems and methods are disclosed to provide static and/or dynamic phase adjustments to a data signal relative to a clock signal. For example, the data signal may be delayed by a coarse delay and/or a fine delay to match the timing of the clock signal independently for each input path (e.g., per input pad). The delay may be as a function of positive and/or negative clock edges.

Abstract: A timing vernier applies a pair of stable bias voltages to intermediate points of an impedance string to establish reliable and calibratable delay cell biases for a fine multiplexer. A coarse input multiplexer is switched to a new timing signal substantially immediately after passing a prior valid timing signal to maximize the time prior to each valid output that the waveform is independent of the prior delay pattern. Logic circuitry is provided for three different phase differential regimes between successive timing signals to ensure that invalid output signals separated by less than a clock period are not produced. Mask commands are inserted into a series of timing control commands to equalize the average rates of writing and reading out the timing control commands with the mask commands skipped at readout.

Abstract: A digital delay line, which includes a plurality of multiplexer delay elements, arranged in sequence with each of the plurality of multiplexer delay elements having an associated control input. A clock signal line is coupled to a clock input of each of the plurality of multiplexers and is operative to provide synchronous, phase aligned clock signals from a clock signal source to each of said clock inputs. A control input is coupled to each of the plurality of multiplexer delay elements and is operative to transmit to each of the plurality of multiplexer delay elements an associated control signal. In response to a first change in the control signal an associated delay element is added to the delay line and in response to a second change the delay element is removed from the delay line.

Abstract: The invention relates to a controllable delay circuit for delaying an electrical input signal wherein the controllable delay circuit is arranged for receiving an input signal and at least one control signal, wherein, in use, the delay circuit delays the input signal by a delay for generating an output signal, wherein the delay is a function of the at least one control signal, wherein the delay circuit comprises a first module for generating a base signal and at least one support signal on the basis of the input signal and the at least one control signal, wherein, in use, the phase and/or the amplitude of the at least one support signal is controllable with respect to the phase and/or the amplitude of the base-signal by means of the at least one control signal, wherein the delay circuit also comprises a second module connected to the first module, which second module comprises a signal-conductor and at least one support conductor, wherein the signal conductor and the at least one support conductor extend, at l

Abstract: A delay cell has selectable numbers of parallel load resistance transistors operable in parallel, and a similarly selectable number of bias current transistors connectable in parallel. The delay cell is preferably differential in construction and operation. A voltage controlled oscillator (“VCO”) includes a plurality of such delay cells connected in a closed loop series. Phase locked loop (“PLL”) circuitry includes such a VCO controlled by phase/frequency detector circuitry. The PLL can have a very wide range of operating frequencies as a result of the ability to control the number of load resistance transistors and bias current transistors that are active or inactive in each delay cell. Such activation/deactivation may be programmable or otherwise controlled.

Abstract: A programmable delay circuit (100) maximizes processor bandwidth to external peripherals by eliminating wait state addition as the only way for satisfying timing requirements. Circuit (100) includes a programmable delay chain (102) connected to a hysteresis circuit (150). A processor control signal is fed into the programmable delay chain (102) which includes at least one switch (104-116) and at least one resistive element (118-126) connected together. A first feedback circuit (128) connects the output of the programmable delay chain (102) to the input (IN2) of the first embodiment (100) to keep the falling edge of the control signal the same without any significant added delay. The hysteresis circuit (150) which provides a stable signal connects to an output driver (180) for driving the processor control signal.

Abstract: A variable delay circuit delays a first input signal in accordance with a delay adjustment signal and outputs the delayed signal as a first delay signal. A decision circuit outputs, in accordance with a phase difference between the first delay signal and a clock signal, an increase or decrease signal. A delay adjustment circuit generates, in accordance with the increase or decrease signal, the delay adjustment signal to adjust the variable delay circuit. Accordingly, even when a discrepancy in timing between the first input signal and clock signal occurs due to a change in temperature, a fluctuation in voltage or the like, a first receiver circuit can receive the first input signal in synchronization with the clock signal without fail. Since the valid period of the first input signal relative to the clock signal can be minimized, the transmission rate of the first input signal can be increased.

Abstract: A variable delay circuit uses a plurality of inverters or inverting gates as delay elements in a delay line. In one embodiment of the invention, the point in the delay circuit at which an input clock signal enters the delay circuit is adjusted to vary the delay of an output clock signal. In another embodiment, the point in the delay circuit from which the output clock signal exits the delay circuit is adjusted to vary the delay of an output clock signal. In either case, the polarity of the input or output clock signal is adjusted as the delay is adjusted so there are always an even number of inverters or inverting gates between an input terminal to which the input clock signal is applied and an output terminal from which the output clock signal is generated.

Abstract: The present invention generally relates to setup/hold time control devices, and more specifically, to a setup/hold time control device which can change setup/hold time of various control signals applied from an input buffer by software operation commands. The setup/hold time control device of the present invention comprises transmission gates for performing selectively switching operations according to a decoded test mode control signal, thereby selectively using a signal delay device in driving of drivers to appropriately control the setup/hold time of various control signals applied from a global bus line. Accordingly, the present invention can provide a technique which can optimize the setup/hold time with small cost in comparison with a physical metal option control system.

Abstract: A synchronous mirror delay includes a ring oscillator that generates a plurality of tap clock signals with one tap clock signal being designated an oscillator clock signal. In response to an input clock signal, a model delay line generates a model delayed clock signal having a model delay relative to the input clock signal. A coarse delay circuit generates a coarse delay count responsive to the oscillator, input, and model delayed clock signals, and activates a coarse delay enable signal responsive to the delay count being equal to a reference count value. A fine delay circuit latches the tap clock signals and develops a fine delay from the latched signals, and activates a fine delay enable signal having the fine delay in response to the coarse delay enable signal. An output circuit generates a delayed clock signal responsive to the coarse and fine delay enable signals going active.

Abstract: An output driver circuit includes a delay device disposed between a signal input and a driver device. The input signal to the driver device can be delayed by a predetermined value with the delay device. The signal amplitude of the output signal from the driver device is compared, in a comparison device, with the signal amplitude of a reference signal at a predetermined time. The time delay for the input signal to the driver device is then set on the basis of the comparison result. A method for adjusting a driver device is also provided.

Abstract: A delay unit for providing an output signal delayed by a delay time with respect to a periodic signal received at its input, the delay unit comprises a first delay cell adapted to receive the periodic signal and to provide as output a first delayed signal corresponding to the input periodic signal but delayed by a variable first delay time. A selection unit receives the first delayed signal and a second signal derived from the periodic signal. A control unit controls the selection unit in order to select one of the first delayed signal and the second signal as the output signal of the delay unit, and further controls the first delay time of the first delay cell.

Abstract: A delay adjustment circuit for decreasing a phase shift between a system clock and a feedback clock from a semiconductor's internal clock. The circuit includes a difference-pulse generator that provides an interim clock 180 degrees out of phase with the feedback clock when the feedback clock is leading the system clock, and equal to the feedback clock otherwise. The difference-pulse generator also provides a difference-pulse signal that is at logic high for a period of time by which the system clock and an inversion of the interim clock are phase shifted. The circuit also includes a delay control unit and a delay unit which delay the interim clock by the period of time. The resulting delayed interim clock, which is 180 degrees out of phase with the system clock, is inverted to provide an internal clock in phase with the system clock.

Abstract: A synchronous DRAM (SDRAM) or a fast cycle RAM (FCRAM) includes capacitors connected by switches to a signal wire. The switches are controlled to connect and disconnect the capacitors to the signal wire. In a test mode, the transmission time of a control signal is tested by connecting various combinations of the capacitors to the signal wire, and then measuring the signal timing. The signal timing of the memory device can be controlled by selecting which and how many of the capacitors are connected to the signal wire.

Abstract: A balanced programmable delay element that has a variable incremental delay. A first inverter is provided that has a first electrode for receiving an input signal, a second electrode, a third electrode, and a fourth electrode for providing an output signal. The second electrode and the third electrode form a first current path, and the first inverter has a propagation delay that is dependent on the current through the first current path. A second inverter is provided that has a first electrode coupled to the fourth electrode of the first inverter for receiving the output signal of the first inverter, a second electrode, a third electrode, and a fourth electrode for providing an output signal. The second electrode and the third electrode form a second current path, and the second inverter has a propagation delay that is dependent on the current through the second current path.

Abstract: The present invention provides a delay circuit that may be used to generate delayed signals. The delay circuit comprises a delay locked loop having an input terminal coupled to a periodic input signal, the delay locked loop generating one or more delayed periodic signals and a control signal for controlling the time delay between the periodic input signal and the delayed periodic signals. The delay circuit also includes a controlled delay circuit for generating one or more delayed periodic signals. The controlled delay circuit has an input terminal for receiving at least one of the delayed periodic signals from the delay locked loop and a delay control terminal coupled to the control signal from the delay locked loop for controlling the time delay between the delayed periodic input signal received from the delay locked loop and the one or more delayed periodic signals generated by the controlled delay circuit.

Abstract: A data delay circuit effectively provides a delayed serial digital data signal, with the ability to change the delay amount continuously, by delaying a lower frequency parallel data clock rather than the serial digital data signal directly. A first delay circuit 102 receives a parallel data clock which is delayed according to a first control signal to provide a delayed parallel data clock. The frequency of the parallel data clock is lower than that of a serial data clock so the first delay circuit 102 may be a delay device that provides a larger delay. A phase-locked loop 114 receives the delayed parallel data clock to generate the serial data clock in phase with the delayed parallel data clock. A parallel-to-serial converter 112 reads an n-bit parallel digital data signal from a memory 100 according to the delayed parallel data clock, and converts the parallel digital data signal to the serial digital data signal according to the serial data clock S_CLK.

Abstract: An output circuit includes a level-change detecting device, a delay adjusting device and a first multiplexer. The level-change detecting device receives the parallel data signal, detects a level change degree of the parallel data signal between a first time point and a second time point, and outputs a select signal according to the level change degree. The delay adjusting device receives a strobe signal and differentially delaying the strobe signal into a first and a second delayed strobe signals with a first and a second delay time, respectively. The first multiplexer is electrically connected to the level-change detecting device and the delay adjusting device, and selects one of the first and the second delayed strobe signals to be outputted in response to the select signal.

Abstract: A delay locked loop which is capable of adjusting the number of delay devices in a delay line and controlling a phase increase or decrease more precisely than the adjustment by the number of delay devices and a phase control method thereof are provided. The delay locked loop includes a phase detector, a delay line, and a delay time adjuster. The phase detector compares the phase of a reference clock signal with the phase of a feedback clock signal and outputs the phase difference between the reference clock signal and the feedback clock signal as an error control signal. The delay line includes a plurality of first delay devices having a fixed delay time and connected in series. The number of first delay devices connected in series is adjusted in response to a shift signal. The delay line receives an input clock signal and outputs an output clock signal.

Abstract: A phase adjustment circuit delays an external clock signal to generate an adjusted clock signal. A phase comparator compares phases of the external clock signal and the adjusted clock signal, and outputs a phase adjustment signal for adjusting a delay time of the phase adjustment circuit. A data output circuit outputs read data to a data terminal in synchronization with the adjusted clock signal. A data input circuit receives write data supplied to the data terminal, in synchronization with the adjusted clock signal. When performing input of the write data and output of the read data successively, switching control between the input operation of the write data and the output operation of the read data only has to be completed within one clock cycle. The clock cycle can thus be reduced to the time required for the switching control. Consequently, maximum frequency of the external clock signal can be increased.

Abstract: The present invention provides apparatus and methods relating to delay circuits. An electronic system includes a deskewing circuit configured to measure a delay and generate a synchronized signal according to the measured delay. The deskewing circuit may configured to detect an overflow condition and respond accordingly, for example by asserting an overflow signal. Further, the deskewing circuit may be additionally or alternatively configured to detect successful measurement of the delay and respond, for example by executing a power saving and/or noise reducing procedure.

Abstract: An inverter output circuit comprises first though third inverters connected in series. The low-potential output of the first inverter has an offset level. The input threshold voltage of the second inverter is set up at a lower level than the low-level offset potential of the first inverter as the level of supply voltage Vdd falls below a predetermined reference level. Thus, the third inverter is fixed to a predetermined condition if the supply voltage drops below the reference voltage, thereby preventing erratic operations of a load connected to the inverter output circuit caused by, for example, a power shut down and a brownout.

Abstract: A delay locked loop has a delay unit with a delay time that can be controlled in a manner dependent on a control signal. In order to generate complementary delayed clock signals, provision is made of switching elements, which tap off the clock signal to be delayed along the series circuit of delay elements. Each of the delay elements has a series circuit of two inverters. One of the delayed clock signals is tapped off in each case at the output of the second of the inverters of the delay elements, and the complementary output signal from the delayed output signals is tapped off at the first of the inverters. What is thus made possible is that, disregarding the frequency of the clock signal to be delayed and the length of the delay time, the complementary delayed clock signals always have the same phase angle with respect to one another.

Abstract: The invention features an output driver for integrated circuits that includes a driver that has a data input connected to the integrated circuit, a data output connected to a transmission line leading to the external circuit, and impedance adjusting means for adjusting the output impedance of the driver circuit according to determinable impedance adjusting data. The output driver also includes a dummy circuit having a dummy driver circuit and transmission line, and an impedance control circuit for controlling the output impedance of the driver circuit. The impedance control circuit controls the impedance of the driver circuit by determining the impedance adjusting data (necessary for matching the output impedance of the dummy driver circuit to the characteristic impedance of the dummy transmission line and outputting the determined impedance adjusting data to the impedance adjusting means of the driver circuit.

Abstract: A delay circuit that delays an input signal to produce an output signal. The input signal and output signals has a delay which is based on a signal relationship between the input signal and a reference signal. The delay circuit includes configurable devices to vary the reference signal to adjust the delay between the input and output signals.

Abstract: A timing generation circuit includes: a delay section including a plurality of delay circuits for sequentially transferring a clock signal therethrough, wherein the clock signal is delayed by a predetermined amount of time before being output from one of the plurality of delay circuits in the delay section; and a control circuit for changing a delay time of at least one of the plurality of delay circuits in the delay section in accordance with a frequency of the clock signal.

Abstract: A circuit and a method for generating a variable delay clock without glitches are provided. A DLL clock output circuit comprises a selection circuit. A plurality of select signals selectively switch the corresponding clock delay lines to be the output signal by the selection circuit. Each of the select signals traverses through a delay switching circuit to adaptively delay the time points at which the select signals switch the clock delay lines to the output signal, so as to produce a glitchless variable delay clock signal.

Abstract: A circuit and method is shown for digital control of delay lines in a delay locked loop (DLL) system. A pair of multiplexors (MUXes) is used to select output taps from a pair of complementary delay lines that delay a reference clock signal in order to lock onto a received clock signal. An output tap from one delay line is used to produce a rising edge in an output clock signal while a corresponding tap in the complementary delay line is used to produce a falling edge in the output signal in order to correct for distortion. The MUXes are controlled based on a phase difference detected between the received clock signal and a feedback clock corresponding to the output clock signal. Another aspect of the present invention provides for generation of a quadrature clock by interpolating between the rising and falling edges selected for the output clock signal. Still another aspect of the present invention provides for selectively disabling unused elements of the delay lines to reduce power consumption.

Abstract: An apparatus comprising one or more input circuits. The input circuit may be configured to generate an output signal in response to (i) an input signal and (ii) an input threshold. The input threshold may be set in response to a control input.

Abstract: A delay circuit includes an output circuit including first and second output elements. The first and second output elements are connected serially between a first power supply source and a second power supply source. The delay circuit further includes a delay element, which is coupled between a first input circuit and an output circuit to generate a first control signal that is delayed with respect to the input signal. The delay circuit still further includes a first node coupled between the delay element and one of the first and second output elements; and a second node, coupled to the other output elements to supply a second control signal having substantially no delay with respect to the input signal.

Abstract: A method and apparatus for delay tuning an integrated circuit which includes a delay element that includes a plurality of delay stages interconnected in a cascaded relationship, each stage imposing an incremental delay upon the input signal when enabled, the delay element receives a selection signal that determines how many of the delay stages are enabled. By varying the select signal, the delay element imposes a variable delay upon the input signal for testing and evaluation.

Abstract: In order to ensure safe and reliable time-delayed signal outputting with a simple redundant structure of a circuit arrangement, a common actuating element acts on two timers with associated A/D converters. In this case, the time delay which is predetermined by the actuating element and is relevant for the outputting of the switching signal is determined by forming the difference between a total resistance, detected by measurement, and a first resistance element, detected by measurement. This is followed by a comparison of the difference, which reflects second resistance elements that is determined by computation, with a second resistance element which is determined by measurement. The switching signal is then output with a time delay when there is a match between the second resistance element determined by measurement and that determined by computation.

Abstract: A synchronous mirror delay (SMD)includes a model delay line that is coupled to a bi-directional delay line. In operation, an initial edge an input clock signal is applied through the model delay line to the bi-directional delay line. The SMD thereafter operates in a forward delay mode to alternately operate the bi-directional delay line in a forward mode and a backward mode to propagate the initial edge of the input clock signal through the bi-directional delay line and delay the initial edge of the input clock signal by a forward delay. In response to a subsequent edge of the input clock signal, the SMD mirrors the propagation of the input clock signal through the bi-directional delay line during the forward mode and further delay the initial edge of the input clock signal by a backward delay that is substantially equal to the forward delay.

Abstract: A time delay circuit including a first transistor having a gate, a drain, a source, and a channel between the source and the drain. The input voltage is applied between the gate and drain and the output is taken between the source and drain. The output voltage follows the gate voltage, and the first transistor gate voltage is substantially constant. The time delay circuit also includes a delay element. The output voltage of the first transistor biases the delay element.

Abstract: A delay circuit and a plurality of accepting circuits are comprised. The input signal supplied from exterior is delayed for a predetermined length of time by the delay circuit, and then it is distributed and output to the plurality of the receiver circuits. The delay time of the delay circuit is adjusted to optimize an accepting timing to an input signal by a clock signal in each of the accepting circuit. The each accepting circuit reliably accepts the delayed input signal respectively in synchronization with a clock signal. Therefore, it is unnecessary to respectively provide a delay circuit in the plurality of the accepting circuits. As a result, the plurality of accepting circuits can reliably accept input signals without enlarging a circuit scale. A plurality of delay circuits, a plurality of accepting circuits, and an operating circuit are comprised. The delay circuit receives a plurality of input signals, and outputs each of the delayed input signals respectively to the plurality of accepting circuits.

Abstract: In an LSI design method, a delay adjusting block group including a plurality of buffer circuit blocks which have different delay amounts but which are the same in connection to the external shape and the external size of the block, the input terminal position and the output terminal position, the input terminal capacitance and the driving capability of the output part including the load dependency, is previously prepared and registered into a circuit library. One buffer circuit block selected from the delay adjusting block group is inserted into a signal path in question, and the delay amount of the signal path in question is roughly adjusted by an existing delay amount adjusting method without replacing the selected buffer circuit block, and thereafter, the delay amount of the signal path in question is roughly adjusted by replacing the selected buffer circuit block by another buffer circuit block included in the delay adjusting block group but having a different delay amount.

Abstract: A digital delay circuit employs a stable reference clock signal, delayed by a reference delay line, to obtain information related to delay characteristics of a matching input delay line. An input clock signal is delayed by the input delay line, which provides a plurality of variously delayed input clock signals based upon the input clock signal. The reference delay line provides a plurality of variously delayed reference clock signals based upon the stable reference clock signal; the delayed reference clock signals convey information related to the operating characteristics of both delay lines. In response to such information, one of the delayed input clock signals can be selected as a delayed clock output. The reference and input delay lines are configured such that the delay circuit consistently generates a delayed clock output having an actual delay that falls within a specified range of delay.

Abstract: According to the present invention, a variable delay circuit includes a delay circuit unit group, a control unit and an offset delay amount memory group. The delay circuit unit group includes a plurality of delay circuit units, and the plurality of delay circuit units includes two paths having different delay amounts. The offset delay amount memory group includes a plurality of offset delay amount memories, and offset delay amounts corresponding to delay amounts of the first paths of the corresponding delay circuit units are set in the plurality of offset delay amount memories. The control unit includes a plurality of subtracting units, and the plurality of subtracting units select paths of the delay circuit units through which an input signal may pass by using a delay setting value and offset delay amounts. It is possible to reduce volume of the circuit and remove a table since the path is selected by calculation.

Abstract: A voltage-boosting generator for reducing the effects due to operating voltage variation and temperature change. The generator comprises a delay line circuit and a voltage boosting circuit. The delay line circuit is used to perform a time delay according to an initial boosting signal and to produce a control signal. The voltage boosting circuit is used to boosted voltage according to the control signal.

Abstract: A precision signal delay apparatus and method for introducing time delay to a signal. Precision delay is introduced by a pair of delay locked loops (DLLs) connected in series each with selectable delay (i.e., a Vernier-type circuit). Nonuniformity in the precision delay is compensated with a delay compensation circuit. The apparatus and method may be used for phase shifting, data delay, precision pulse width modulation, and precision time windowing.

Abstract: A control circuit for a FIFO datapath is described. The control circuit consists of a chain of Muller C-elements with adjustable delay elements placed between the output of each Muller C-element and one of the inputs of the preceding and successive Muller C-elements. The adjustable delay elements allow the control circuit to match the delays of processing elements in the datapath, thereby creating overall faster operation.

Abstract: A clock synchronization circuit. The clock synchronization circuit composed of a digital DLL outputs a clock signal delayed by a variable delay line and a clock signal delayed by an additional delay cell, mixes the two clock signals, and outputs an internal clock signal having a smaller delay than a delay time of a delay cell, thereby rapidly precisely synchronizing an external clock signal and the internal clock signal. In addition, a driving unit and a control unit for adjusting a duty cycle are provided to set up a ratio of 50%, thereby improving operation performance.

Abstract: A timing generation circuit includes: a delay section including a plurality of delay circuits for sequentially transferring a clock signal therethrough, wherein the clock signal is delayed by a predetermined amount of time before being output from one of the plurality of delay circuits in the delay section; and a control circuit for changing a delay time of at least one of the plurality of delay circuits in the delay section in accordance with a frequency of the clock signal.

Abstract: A clock distribution network is provided which includes variable-delay element. The variable-delay element consists of an inverter and a digitally adjustable resistor. The digitally adjustable resistor includes a plurality of transistors provided in plurality of rows and a plurality of columns. The variable-delay element functions logically equivalent to the inverter in which the delay is varied in accordance with the variance in resistance of the digitally adjustable resistor.

Abstract: A signal phase adjustment circuit to set an optimum phase by adjusting the difference in delay times between signal lines even when the distribution of the amount of phase modification that can be received normally is divided into a plurality of continuous regions. The amount of phase modification of the transmitted signal is allowed to fluctuate during one cycle of the operational frequency of the circuit. Determination of whether or not the reception signal during this interval can be received is continued, and the distribution of amount of phase modification that can be normally received is detected. The detected amount of phase modification defines continuous regions, and an optimum phase region is specified by selecting a region having a width of a specified value or more or the region having the greatest width. The optimum amount of sampling phase modification is determined from the upper and lower limit values of this region.

Abstract: An apparatus including a switched voltage bit cell (SVBC) array to receive an input voltage signal, each bit cell of the SVBC array configured to add a voltage to the input voltage signal and a delay locked-loop configured to delay an output voltage signal of each bit cell of the SVBC array by a determined step.

Abstract: According to one aspect of the invention, a method is provided in which an input signal is received at a first node of a buffer circuit. The propagation of the input signal from the first node to a second node in the buffer circuit is delayed by a delay period based upon a first control input. The delay period is adjusted by a factor based upon a second control input.