Abstract: A digital high speed programmable delayed locked loop (DLL) includes a zero degree phase shift digital delay line, at least one intermediate phase shift digital delay line, a three hundred and sixty degree phase shift digital delay line, and a digital control module. The zero degree phase shift, intermediate phase shift, and 360 degree phase shift digital delay lines are operably coupled to produce, from a clock signal, zero phase shifted, intermediate phase shifted, and 360 phase shifted representations, respectively, of the clock signal. The digital control module is operably coupled to produce an intermediate control signal for the intermediate phase shift digital delay line and a 360 degree control signal for the 360 degree phase shift digital delay line based on a phase difference between the zero phase shifted representation of the clock signal and the three hundred and sixty degree phase shifted representation of the clock signal.

Abstract: A circuit for quickly accomplishing highly accurate phase detection using low power is described. The circuit includes a phase decision circuit that receives two clock signals and detects the phase relationship between the two signals by determining which signal was received first. In response, the phase decision circuit generates respective logic signals to reflect the phase relationship determination. The circuit also includes a latch circuit that receives the logic signals from the phase decision circuit and holds the phase relationship determination of the circuit a predetermined time after a predetermined transition of both clock signals have occurred. Methods and systems are also disclosed.

Abstract: An electronic device comprises an electronic component and an integrated circuit, wherein the integrated circuit is configured to generate a system clock and an external clock having a programmable delay from the system clock, provide the external clock to the electronic component, determine a delay range between system clock and the external clock in which the integrated circuit and the electronic component can communicate, and program the external clock with one of a plurality of predetermined delay values based on the delay range.

Abstract: A method and apparatus for pre-clocking have been disclosed.

Abstract: The data output control signal generating circuit includes a delay correction signal generating unit that delays an input signal by a phase difference between a clock and a delay locked loop clock, and latches the delayed signal to generate a plurality of output enable signals. A column address strobe latency control multiplexer selects the output enable signal corresponding to column address strobe latency among the plurality of output enable signals, on the basis of the signal obtained by delaying the input signal by the phase difference between the clock and the delay locked loop clock, and outputs the selected signal as the data output control signal.

Abstract: A layout method for a semiconductor integrated circuit according to the present invention is a layout method for a semiconductor integrated circuit including plural delay adjustment cells each of which adjusts a delay amount of a signal line. The layout method includes: placing the plural delay adjustment cells; adjusting delay amounts of the plural delay adjustment cells placed in the placing; extracting delay adjustment cells of a same kind from among the plural delay adjustment cells having the delay amounts adjusted in the adjusting; and consolidating the delay adjustment cells of the same kind extracted in the extracting, to obtain a shared delay adjustment cell.

Abstract: A delay locked loop operates over a wide range of frequencies and has high accuracy, small silicon area usage, low power consumption and a short lock time. The DLL combines an analog domain and a digital domain. The digital domain is responsible for initial lock and operational point stability and is frozen after the lock is reached. The analog domain is responsible for normal operation after lock is reached and provides high accuracy using smaller silicon area and low power.

Abstract: A clock generator for generating an output clock signal synchronized with an input clock signal having first and second adjustable delay lines. The first adjustable delay lines is adjusted following initialization of the clock generator to expedite obtaining a lock condition following the initialization. The second adjustable delay line is adjusted after synchronization is achieved with the first adjustable delay line, or when the first adjustable delay line reaches a maximum adjustable delay. The first adjustable delay line is reset when a lock condition is initially obtained, and the second adjustable delay line is adjusted to compensate for the resetting of the first adjustable delay line.

Abstract: The invention relates to an apparatus for precise modulation of signal phase and signal delay, respectively, and signal amplitude, comprising a first fixed-delay device having its input coupled to an input signal, a first variable delay device having its input coupled to said input signal and having a control input for delay adjustment, a first amplitude control device in series with the first variable delay device, providing at its output an amplitude controlled signal and having a control input for adjusting the output amplitude, a phase detector with linear characteristic having its two inputs connected to the output of the fixed-delay device and the output of the first amplitude control device, an error measurement device having its negative input connected to the output of the phase detector and its positive input connected to a control signal, an amplifier with low-pass characteristic having its input connected to the output of the error measurement device and its output to the control input of the firs

Abstract: An off-chip driver circuit including a plurality of delay circuits, at least two of which have different delay times, in which the delay circuits receive a data signal and generate delayed data signals, respectively. The circuit also includes a plurality of off-chip drivers for respectively receiving the delayed data signals from the respective delay circuits and generating respective output signals in response to respective control signals, wherein the total number of the off-chip drivers to be activated at the same time is changed by the respective control signals which are generated in response to a desired drivability, and the activated off-chip drivers sequentially generate the output signals in response to the delay times, thereby increasing a total drivability of the off-chip driver circuit.

Abstract: A circuit for timing adjustment includes a PLL circuit configured to generate a phase-adjusted clock signal in response to phase comparison between an input clock signal and a delayed clock signal, a feedback path configured to delay the phase-adjusted clock signal for provision as the delayed clock signal to the PLL circuit, a first timing correction circuit configured to add a predetermined delay time to the feedback path, an output data circuit configured to supply output data at first timing responsive to the phase-adjusted clock signal, a second timing correction circuit configured to delay the first timing by the predetermined delay time to generate second timing different from the first timing, and an input data circuit configured to latch input data at the second timing.

Abstract: A data input apparatus includes: a phase detector comparing a phase of a data strobe signal with a phase of a clock signal to output a first phase comparison signal and a second phase comparison signal. A first delay controller determines whether a first data input strobe signal is delayed to output the determined signal as a second data input strobe signal in response to the first phase comparison signal. An internal clock synchronizer synchronizes first aligned data and second aligned data with the clock signal in response to the second data input strobe signal, to output the synchronized first and second data as first internal output data and second internal output data, respectively. A second delay controller determines whether the first internal output data and the second internal output data is delayed in response to the second phase comparison signal, to output the first internal output data and the second internal output data as first output data and second output data, respectively.

Abstract: A clock signal generator and method thereof are provided for a system to generate an output signal. The apparatus comprises: a delay circuit for generating a delayed clock with a first time, a delay module for generating delayed signal(s), and a decision circuit for comparing the delayed signal(s) with the delayed clock to obtain the relative relation between the delay time and the first time and controlling a delay time of an input signal according to the relative relation to generate the output signal.

Abstract: In a semiconductor device of the present invention, a clock is not changed instantaneously but it is changed over maximum N+1/M clocks (N: integer not less than 2) by shifting delay cells in a step by step manner to make the phase state of a previous reference signal and the phase state of a present reference signal coincide with each other, whereby the clock is synchronized with the reference signal with accuracy, and the duty of the output clock is kept constant. With this semiconductor device, it is possible to prevent the duty of the clock from being discontinuous when a signal whose reference signal does not coincide with the clock is inputted and reset is made to a rising edge of this reference signal.

Abstract: A clock generator for generating an output clock signal synchronized with an input clock signal having first and second adjustable delay lines. The first adjustable delay lines is adjusted following initialization of the clock generator to expedite obtaining a lock condition following the initialization. The second adjustable delay line is adjusted after synchronization is achieved with the first adjustable delay line, or when the first adjustable delay line reaches a maximum adjustable delay. The first adjustable delay line is reset when a lock condition is initially obtained, and the second adjustable delay line is adjusted to compensate for the resetting of the first adjustable delay line.

Abstract: A processor system has a first device, a clock control circuit and a processor. The first device receives a clock signal, runs a plurality of operations including a lengthy operation requiring more than a single clock cycle to complete, and produces a control signal when the lengthy operation is activated. The clock control circuit receives the clock signal and outputs a gated clock signal only when the first device is not producing the control signal. The processor unit runs off of the gated clock signal. The first device may be a memory, and the lengthy operation may be correction of a soft error in memory. According to a second aspect, the first device requires a longer clock cycle rather than more clock cycles. The clock can be gated to effectively double the period when the lengthy operation is activated.

Abstract: There is a clock recovery circuit to correct the timing relationship between a data signal and clock signal. The clock recovery circuit comprises a phase detector having an input for receiving a clock signal having a period, an input for receiving a data signal, and an input for receiving a window signal. The window signal has a period equal to the period of the clock signal and phase difference of ?90° with respect to the clock signal. The phase detector generates an up output and a down output while maintaining a phase relationship of the up output and the down output in response to the phase relationship between the clock signal and the data signal.

Abstract: The four types of the controllable idle time current mirror circuits are presented with an improvement in productivity, performance, cost, chip area, power consumption, and design time. The controllable idle time current mirror circuits basically include a sensing block, triggering transistors, current mirror, current source, a n-bit control circuit array, and a feedback line. If the sensing voltage does not reach the expected voltage compared to the midpoint voltage of the sensing gate, the triggering transistors provide a current to its output through the current mirror until the voltage at feedback reaches the midpoint voltage. Time to reach the midpoint voltage at a load is simply equal to the charge stored at the load divided by the total current, which is controlled by an N-bit digital input and a device aspect ratio of each triggering transistor.

Abstract: A voltage controlled delay loop and method are disclosed for clock and data recovery applications. The voltage controlled delay loop generates clock signals having similar frequency and different phases. The voltage controlled delay loop comprises at least one delay element to generate at least two phases of a reference clock; a central interpolator for interpolating the at least two phases of the reference clock to generate an interpolated signal; and an input that injects the interpolated signal into a delay stage. The central interpolator provides a fine phase control. In addition, a coarse phase control can optionally be achieved by selectively injecting the interpolated signal into a given delay stage. A further voltage controlled delay loop is disclosed with coarse and fine phase control using a number of interpolators.

Abstract: A data signal is detected and compared with a reference value. A displacement time is determined as a function of the difference between the reference value and the signal level of the data signal. The data signal is buffer-stored and output in a manner that is temporally delayed by the displacement time. Accordingly, the data signal has a predetermined value at a predetermined point in time after the buffer-storage. Consequently, the data signal waveform can be defined with respect to time. As a result, a precise signal waveform is prescribed, and time periods for detecting the data signal can be precisely defined.

Abstract: An integrated circuit chip including a first delay circuit and a second delay circuit. The first delay circuit has a first delay circuit topology configured to delay a signal a first delay. The second delay circuit has a second delay circuit topology configured to provide a second delay in a circuit loop that is configured to be monitored and provide an oscillating signal. The second delay circuit topology is substantially the same as the first delay circuit topology and the first delay circuit is configured to be trimmed to adjust the first delay based on the second delay and the oscillating signal.

Abstract: A clock synchronization circuit for synchronizing a first clock signal and a second clock signal for data transfer from a first function block, which is clocked by the first clock signal, to a second function block which is clocked by the second clock signal, where the clock synchronization circuit has a sampling unit for sampling the second clock signal using the first clock signal in order to generate samples and edge detection values of the sampled second clock signal, a logic circuit for outputting the generated edge detection values as a reconstructed clock signal and generating an Edge-too-Early signal and an Edge-too-Late signal; and a signal delay circuit, which delays the reconstructed second clock signal on the bases of the Edge-too-Early signal or the Edge-too-Late signal.

Abstract: In one embodiment, an integrated circuit provides a test access port that communicates with scan chain registers in a processor core. The integrated circuit synchronizes data transferred between a debug controller that operates under control of a test clock (TCK) and the processor core that operates under control of a processor clock (CLK).

Abstract: A delay locked loop circuit (200) in which multiple outputs are produced. A single delay line (24) is shared among multiple tap selection circuits (256A, 265B, 265C). Fixed phase shifts (412) can be introduced between multiple outputs. A modulating signal can be used in the tap selection processing to produce digital amplitude, frequency and/or phase modulation.

Abstract: A phase detection system for use with a synchronous mirror delay or a delay-locked loop in order to reduce the number of delay stages required, and therefore increase the efficiency, is disclosed. The invention includes taking a clock input signal and a clock delay or feedback signal, each having timing characteristics, and differentiating between four conditions based upon the timing characteristics of the signals. The phase detector and associated circuitry then determines, based upon the timing characteristics of the signals, which of a number of phase conditions the signals are in. Selectors select the signals to be introduced into the synchronous mirror delay or delay-locked loop by the timing characteristics of the phase conditions. The system is able to utilize the falling clock edge of the clock input signal, and the lock time is decreased under specific phase conditions.

Abstract: Phase locked loop circuitry operates digitally, to at least a large extent, to select from a plurality of phase-distributed candidate clock signals the signal that is closest in phase to transitions in another signal such as a clock data recovery (“CDR”) signal. The circuitry is constructed and operated to avoid glitches in the output clock signal that might otherwise result from changes in selection of the candidate clock signal.

Abstract: The invention refers to a clock distortion detection method, and a clock distortion detector including a first input for receiving a first clock signal, a second input for receiving a second clock signal, and at least one mirror delay element.

Abstract: An improved interpolator includes a replica delay line and an interpolated delay edge generator. The replica delay line provides two replica delay edges to the interpolated delay edge generator. The interpolated delay edge generator selectively generates an interpolated delay edge while maintaining a substantially constant capacitive loading on the two replica delay edges. The replica delay line may comprise a delay cell of four current-starved inverter delay stages or four capacitor-loaded inverter delay stages.

Abstract: A register controlled delay locked loop includes a clock generation unit which receives an external clock signal for generating a source clock signal by buffering the external clock signal and for generating a delay monitoring clock signal and a reference clock signal by diving the source clock signal by a natural number; a delay line control unit which receives the reference clock signal and a feed-backed clock signal for generating a normal shift control signal and an acceleration shift control signal based on a result of a comparison between phases of the reference clock signal and the feed-backed clock signal; a delay line unit which receives the source clock signal for generating a delay locked clock signal by delaying the source clock signal according to a delay amount of the delay line unit determined by the normal shift control signal and the acceleration shift control signal; and a delay model unit for estimating a delay amount generated while the external clock signal is passed to a data output pin

Abstract: Clock capturing synchronization circuitry first generates a synchronized clock signal from a reference clock signal, then captures the synchronized clock signal, and continues to output a synchronized clock signal after the reference clock signal is removed. The clock capturing synchronization circuitry also reduces input referred jitter in the synchronized clock signal.

Abstract: A clock generator for generating an output clock signal synchronized with an input clock signal having first and second adjustable delay lines. The first adjustable delay lines is adjusted following initialization of the clock generator to expedite obtaining a lock condition following the initialization. The second adjustable delay line is adjusted after synchronization is achieved with the first adjustable delay line, or when the first adjustable delay line reaches a maximum adjustable delay. The first adjustable delay line is reset when a lock condition is initially obtained, and the second adjustable delay line is adjusted to compensate for the resetting of the first adjustable delay line.

Abstract: A data processing system includes first, second, and third agents connected to a shared bus. The third agent is able to receive information via the shared bus from the first agent or from the second agent. The third agent includes a skew compensation circuit to determine signal skew in signal received via the shared bus and to compensate for the skew by adding delay into selected signals of the bus. The skew compensation circuit determines whether the first agent or the second agent is the sender of information received by the third agent via the shared bus. The skew compensation circuit alters the skew compensation based on the identity of the sender such that the delay into the bus signals is specific to the corresponding sender.

Abstract: A delay-locked loop (DLL) capable of directly receiving external clock signals is provided. The DLL comprises a level selector, a control signal generator, and an internal clock signal generator. The level selector receives an external clock signal, and directly outputs the external clock signal, or changes a level of the external clock signal and outputs a changed external clock signal, in response to a control signal. The control signal generator generates the control signal. The internal clock signal generator receives an output signal of the level selector and the external clock signal, and generates an internal clock signal synchronized to a phase of an output signal of the level selector.

Abstract: Various systems and methods providing signal delay compensation for circuits such as a multi-pair gigabit Ethernet transceiver are disclosed. In an analog implementation a buffer with an adjustable delay may be used to minimize the delay mismatch between clock trees. The delay of the adjustable-delay buffer is controlled by bias voltages that determine the charging and discharging current to the adjustable buffer. A phase detector circuit is used to compare the clock phases for rising and falling edges, and to adjust the bias voltages that control these edges. In a digital implementation a selector switch, responsive to a phase detector, may be used to route clock signals through circuit elements to delay clock signals.

Abstract: A delay locked loop (DLL) circuit comprising: a fundamental phase comparator for detecting a fundamental phase difference of two input signals; a delay circuit; a delay control circuit for adjusting a delay time of the delay circuit in response to an output signal of the fundamental phase comparator; and at least one further phase comparator for detecting a phase difference other than the fundamental phase difference such that an amount of change of the delay time is changed in accordance with the fundamental phase difference.

Abstract: The present invention relates in general to the field of generation of precise electrical signals, in particular, to a technique for providing accurate delays of signals using a controllable delay line, and is applicable to the areas of high speed communication and memory testing equipment. According to the present invention, an auxiliary reference channel having a delay line which is identical to the main delay line is incorporated into vernier silicon die to allow automatic adjustment of the delay in the main delay line using a reference periodical signal applied to the auxiliary delay line.

Abstract: A detector detects timing in a digital data flow with a bit-time equal to T. A first circuit generates four local timing signals each having periods substantially equal to the bit-time. Each of the four local timing signals are out of phase with one another by ¼ period. A second circuit samples the four local timing signals upon each transition of a first type for determining, based upon the sampling, whether two of the four local timing signals forming a pair of reference signals that are out of phase by ½ period are advanced or delayed relative to the timing of the data flow. The second circuit controls the first circuit for delaying or advancing the four local timing signals based upon the pair of reference signals.

Abstract: An interleaved delay line for use in phase locked and delay locked loops is comprised of a first portion providing a variable amount of delay substantially independently of process, temperature and voltage (PVT) variations while a second portion, in series with the first portion, provides a variable amount of delay that substantially tracks changes in process, temperature, and voltage variations. By combining, or interleaving, the two types of delay, single and dual locked loops constructed using the present invention achieve a desired jitter performance under PVT variations, dynamically track the delay variations of one coarse tap without a large number of delay taps, and provide for quick and tight locking. Methods of operating delay lines and locked loops are also disclosed.

Abstract: A SONET multiplexed system architecture that permits greater levels of integration. The architecture includes a time slot interchanger for routing information from at least one SONET input signal path associated with a respective first time slot to at least one SONET output signal path associated with a respective second time slot. Each input signal path includes a pointer interpreter, and each output signal path includes a FIFO buffer serially coupled to a pointer generator. The architecture further includes a synchronization buffer in each input signal path for transferring the input signal to the clock rate of the time slot interchanger. The architecture permits greater levels of integration when the time slot interchanger has more inputs than outputs, and/or the time slot interchanger provides the output signal to a pointer processor to transfer the output signal to the clock rate of the output signal path.

Abstract: An oversampling clock recovery method according to this invention generates non-uniform three-phase clock signals CLKa, CLKb, and CLKc having non-uniform intervals for one bit of an input data i and controls phases of the clock signals so that either phase of two edges of two-phase clock signals CLKb and CLKc having a relatively narrower interval of 57 ps synchronizes with a phase of a transition point of the input data i. By changing clock signals to be phase-locked in three delay locked loops (DLLs), a phase interval of 57 ps is formed.

Abstract: A method and apparatus are disclosed for efficiently doubling a first frequency of a first clock signal. A second clock signal at a second frequency is generated by dividing the first frequency of the first clock signal by two, such that the second frequency is half of the first frequency and a duty cycle of the second clock signal is 50%. Also, a set of phase-delayed clock signals is generated in response to the second clock signal such that the set of phase-delayed clock signals are delayed in phase with respect to the second clock signal. Further, the set of phase-delayed clock signals is combined to generate a third clock signal at a third frequency, such that the third frequency is twice that of the first frequency and a duty cycle of the third clock signal is 50%.

Abstract: A closed loop delay line system (700) includes a phase lock loop that provides a phase lock output signal (715). A delay line (702) includes a clock input, a delay line output, and a delay line bias input. A bias signal provided to the delay line bias input (727) adjusts the speed of the delay line (702). A phase detector (720) compares phase between a first timing signal input (704) and the delay line output (706). A bias adjust circuit (726) mixes the phase compare output signal (725) and the phase lock output signal (715) to provide a combination bias signal (727) to the delay line (702). Additionally, the relative timing position of strobe outputs (734) from the delay line (702) can be individually adjusted.

Abstract: The present invention relates to a semiconductor device; and, more particularly, to a delay adjusting circuit which is required to adjust a delay time of an internal circuit in a test mode and required to verify a characteristic and a margin of the semiconductor device. The delay adjusting apparatus according to the present invention comprises: a normal delayer for delaying an input signal from an external circuit; a delay time storage for maintaining a predetermined delay time produced by a control signal and delaying the input signal based on the predetermined delay time; and a selector for selectively outputting one of output signals from the normal delayer and the delay time storage in response to a test mode signal.

Abstract: There is provided a transmission circuit which can certainly perform transmission of data of digital form between two circuits operating in synchronization with two clock signals having the same frequency even if phase shift is generated between the two clock signals. According to a phase difference between a clock signal CK1 and a clock signal CK2, the transmission circuit performs either one of an operation of outputting pre-transmission digital data inputted to the transmission circuit as it is or after it is inverted, and an operation of sampling it in synchronization with the clock signal CK2 and outputting it as it is or after it is inverted.

Abstract: A semiconductor integrated circuit device including (a) an actual input circuit (03A, 04A), (b) an actual output circuit (05A, 06A), (c) a replica input circuit (12A) having the same characteristics as those of the actual input circuit, (d) a replica output circuit (11A) having the same characteristics as those of the actual input circuit, (e) an oscillating circuit (15A) which operates in accordance with external triggers, and (f) a skew-comparing circuit (10A) which compares a signal transmitted from the oscillating circuit and passing through the actual input circuit and the actual output circuit, to a signal transmitted from the oscillating circuit and passing through the replica input circuit and the replica output circuit to detect a delay error between the actual input and output circuits and the replica input and output circuits, wherein delays in the replica input and output circuits are compensated for in accordance with the delay error detected by the skew-comparing circuit.

Abstract: A phase locked loop (PLL) with low steady state phase errors utilizes a delay unit to delay an input signal or a reference clock so as to lower the steady state phase errors of the PLL. A calibration circuit is used to adjust the delay time of the delay unit and includes a signal generator for generating a simulation input signal and a simulation reference clock according to a phase locked clock; a delay unit for delaying the simulation reference clock and generating a delayed reference clock; a phase detector for detecting the phase error between the simulation input signal and the delayed reference clock and generating charge control signals; a charge pump and an integrator for generating an error voltage according to the charge control signals; a delay time control unit for adjusting the delay time of the delay unit according to the error voltage; and a voltage control oscillator for generating the oscillation clock according to a reference control voltage.

Abstract: A memory system includes a memory device that includes an active termination circuit. The memory system further includes a controller circuit that includes a frequency control circuit that is configured to modulate a system clock between a first frequency value and a second frequency value, greater than the first frequency value, responsive to a control signal. The controller circuit is further configured to determine an active termination value for the active termination circuit responsive to the system clock at the first frequency value, and to apply commands to the memory device responsive to the system clock at the second frequency value.

Abstract: A semiconductor device includes an external resistor for establishing a delay of a signal relative to another signal in the device. The resistor may be external to a buffer, such as a zero-delay buffer, that receives an input signal generates one or more output signals that relate to the input signal. The delay may be introduced either before or after the buffer.

Abstract: Various systems and methods providing signal delay compensation for circuits such as a multi-pair gigabit Ethernet transceiver are disclosed. In an analog implementation a buffer with an adjustable delay may be used to minimize the delay mismatch between clock trees. The delay of the adjustable-delay buffer is controlled by bias voltages that determine the charging and discharging current to the adjustable buffer. A phase detector circuit is used to compare the clock phases for rising and falling edges, and to adjust the bias voltages that control these edges. In a digital implementation a selector switch, responsive to a phase detector, may be used to route clock signals through circuit elements to delay clock signals.

Abstract: A master clock signal source (10) generates a master clock signal having a frequency equal to N times the bit rate of received data, where N is a positive integer. A modulo-N counter (12) counts the master clock signal. An edge detecting circuit (4) detects a transition of the received data from a H level to a L level. A counter (8) counts the master clock signal and resets the modulo-N counter (12) if the count counted during a time period in which three edge representative signals occur is 2N. In accordance with the count in the modulo-N counter 12, a clock generating unit 14 generates a clock signal.