Abstract: A prescaler that operates in a broad band. The prescaler includes a buffer and a counter. The buffer includes a first amplification circuit, which has three inverter circuits of different drive capacities, a second amplification circuit, which has four series-connected inverter circuits, and a feedback circuit. One of the inverter circuits is connected between a capacitor and an inverter circuit via a first switch circuit and a second switch circuit. This varies the drive capacity of the first amplification circuit. The feedback circuit functions as a variable resistor having two transistors.

Abstract: An electronic circuit comprises a delay circuit that with a chain of saw tooth delay stages (10a-d), coupled in a loop to form an oscillator for example. Each stage comprises an integrating circuit (104) and a current modulator (106) coupled to the integrating circuit (104). Each stage triggers a transition in the next stage when the integration result reaches a level defined by a reference voltage. Correlating circuitry (102, 30, 32, 34) is provided with current outputs to generate currents to the current modulators (106) and reference voltages for the saw tooth delay stages (10a-d). The reference voltages are generated at least partly from a common reference (102c), so that noise in the currents from the current modulators (106) and reference voltages is correlated in a way that at least partly cancels the effect of the noise on the delay time.

Abstract: An adjustable buffer including a first series of P-channel devices having current electrodes coupled in series between a first voltage supply and a first output node, and a first series of N-channel devices having current electrodes coupled in series between the first 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 first output node. A clock distribution system including multiple uniform adjustable buffers coupled between at least one root node and multiple destination nodes, where each uniform adjustable buffer is adjustable between a minimum delay and a maximum delay.

Abstract: A controllable delay line includes an anti-jitter unit, a dependent current source, a first current mirror, a second current mirror, a regulation capacitor, a compensation capacitor and an output buffer unit. The anti-jitter unit receives a first bias voltage and produces a second bias voltage based on the first bias voltage. When the voltage source used in the controllable delay line has a variation, the second bias voltage varies therewith. The regulation capacitor is used for reducing the variation of the voltage difference between the voltage source and a node voltage of the first current source. The compensation capacitor is used for reducing the influence of a transition of the input signal of the output buffer unit on the node voltage, so as to lower the jitter amount of the output signal of the output buffer unit.

Abstract: A variable delay circuit comprising a first delay element configured to delay an input signal, a second delay element coupled to the first delay element in parallel and also configured to delay the input signal, a control current supply section configured to supply control currents for adjusting a delay amount of the first delay element and a delay amount of the second delay element, and an output signal selecting section configured to select any one of an output signal from the first delay element and an output signal from the second delay element according to a selecting signal for selecting delay time of the input signal.

Abstract: A method and apparatus for source synchronous testing have been disclosed. In one case a data signal is delayed and a selectively activated delay is applied to a clock. This allows the clock to be positioned before the data and also after the data.

Abstract: A timing control circuit DLY1 receives clock signal CKa with period T1 and activation signal ACT and outputs fine timing signal FT with delay of m*T1+tda measured from the clock signal where m denotes a non-negative integer and tda denotes delay in the analog delay element. The timing control circuit DLY1 comprises a coarse delay circuit CD and a fine delay circuit FD. The coarse delay circuit CD comprises a counter for counting a rising edge of the clock signal CKa after receiving activation signal ACT and outputs coarse timing signal CT with delay of m*T1 measured from a rising edge of the clock signal CKa. The fine delay circuit FD comprises a plurality of analog delay elements and outputs fine delay timing signal FT with delay of tda measured from the coarse timing signal CT. Variation in delay of timing signal is reduced.

Abstract: A method, circuit, and system are disclosed. In one embodiment, the method comprises receiving a differential clock signal from two clock signal lines into a first differential pair of transistors of a first size, receiving the differential clock signal from the two clock signal lines into a second differential pair of transistors of a size smaller than the first size, converting the differential clock signal into a single-ended clock signal, outputting the single-ended clock signal through an inverter, and synchronizing any differential clock phase error by controlling the transconductance between the first differential pair of transistors and the second differential pair of transistors.

Abstract: Disclosed herein is a VDL/DLL architecture in which the power supply to the VDL, VccVDL, is regulated at least as a function of the entry point of the input signal (ClkIn) into the VDL. Specifically, VccVDL is regulated to be higher when the delay through the VDL is relatively small (when the entry point is toward the right (or minimum delay) edge of the VDL) and is reduced when the delay is relatively high (when the entry point is toward the left (or maximum delay) edge of the VDL). This provides for graduated delays across the stages of the VDL, but without the need to design each stage separately. Other benefits include a VDL/DLL design operable over a wider range of frequencies, and a reduced number of stages, including a reduced number of buffer stages. Moreover, when the disclosed technique is used, buffer stages may be dispensed with altogether.

Abstract: A system, apparatus and method for delaying a signal, such as a high-speed signal are disclosed. A multi-stage delay cell is described in which the amount of delay applied to a signal depends on which stages are activated within the cell. In various embodiments of the invention, noise caused by transitions between various delay times within the cell is reduced by efficiently managing voltage states on each of the stages.

Abstract: A first variable delay circuit delays an input signal, introduces a first delay into a first edge of the input signal, and generates a first delay signal. A second variable delay circuit delays the input signal, introduces a second delay into a second edge, and generates a second delay signal. A control circuit controls the first variable delay circuit and the second variable delay circuit such that the first delay and the second delay are identical. A generation circuit combines the first edge of the first delay signal and the second edge of the second delay signal, and generates a third delay signal.

Abstract: A delay line comprises first and second delay arrays and a multiplexer. The first delay array receives a clock signal and a delay control signal, and delays the clock signal to output a first delay array clock signal according to the delay control signal. The second delay array receives a power control signal, the first delay array clock signal and the delay control signal. The second delay array is turned on or off according to the power control signal. If the second delay array is turned on, the second delay array delays the first delay array clock signal to output a second delay array clock signal according to the delay control signal. The multiplexer receives a selecting control signal, the first and second delay array clock signals, and outputs the first delay array clock signal or the second delay array clock according to the selecting control signal.

Abstract: A voltage-controlled oscillator includes a plurality of variable delay circuits, wherein a first differential output signal of an adjacent previous stage is provided as a first differential input signal and a second differential output signal of a second previous stage is provided as a second differential input signal. Each variable delay circuit includes a loading circuit including first and second loading units, a first input circuit including first and second input transistors gated by the first differential input signal, a second input circuit including third and fourth input transistors gated by the second differential input signal, first and second current sources connected between a first common node and a second power source and in electrical parallel with each other, and third and fourth current sources connected between a second common node and the second power source and in electrical parallel with each other.

Abstract: An output circuit comprises an input node, an output node, a first output transistor, a second output transistor, a first slew rate control circuit, and a second slew rate control circuit. The first output transistor and the second output transistor are coupled in series. The first slew rate control circuit is coupled between the first output transistor and a first power supply terminal. The second slew rate control circuit is coupled between the second output transistor and a second power supply terminal. The input node is coupled to gates of the first output transistor and the second output transistor. The output node is coupled to a common node of the first output transistor and the second output transistor.

Abstract: A new method to sample a digital input signal is achieved. The method comprises sampling a digital input processed through a first digital buffer. The sampling is at the rising edge of a system clock. The switching threshold of a second digital buffer is updated. The digital input processed through the second digital buffer is sampled. The sampling is at the falling edge of the system clock. The switching threshold of the first digital buffer is updated. A digital sampling circuit is achieved.

Abstract: A delay circuit for delaying an input signal according to a desired delay time setting and outputting the same is provided. The delay circuit includes: a delay element for delaying the input signal for a delay time based on a given supply current and outputting the same; a current supply section for generating a supply current; a voltage generating section for generating a base voltage dependent on a delay time setting; and a control section for converting a base voltage to a control voltage dependent on the characteristic of the current supply section and providing the same to the current supply section in order to cause the current supply section to generate the supply current. The current supply section may have a predetermined conductivity and include a first MOS transistor for applying a drain current to the delay element as the supply current.

Abstract: One embodiment of the present invention sets forth a set of three building block circuits for designing a flexible timing generator for an integrated circuit. The first and second building blocks include delay elements that may be customized and fine-tuned prior to fabrication. The third building block may be tuned prior to fabrication as well as after fabrication. The three building blocks may be incorporated into a modular architecture, enabling designers to easily generate well-characterized, flexible, generic timer circuits.

Abstract: Disclosed is a timing control circuit which receives a first clock having a period T1 and a group of second clocks of L different phases (where L is a positive integer) spaced apart from each other at substantially equal intervals and which generates a fine timing signal delayed from the rising edge of the first clock by a delay td of approximately td=m·T1+n·(T2/L), where m and n are non-negative integers. The timing control circuit has a coarse delay circuit and a fine delay circuit. The coarse delay circuit counts the rising edges of the first clock after an activate signal is activated and generates a coarse timing signal delayed from the first clock by approximately m·T1. The fine delay circuit has a circuit which, after the activate signal is activated, detects a second clock, which has a rising edge that immediately follows the rising edge of the first clock, from among the group of L-phase second clocks.

Abstract: An electronic circuit comprises a delay circuit that with a chain of saw tooth delay stages (10a-d), coupled in a loop to form an oscillator for example. Each stage comprises an integrating circuit (104) and a current modulator (106) coupled to the integrating circuit (104). Each stage triggers a transition in the next stage when the integration result reaches a level defined by a reference voltage. Correlating circuitry (102, 30, 32, 34) is provided with current outputs to generate currents to the current modulators (106) and reference voltages for the saw tooth delay stages (10a-d). The reference voltages are generated at least partly from a common reference (102c), so that noise in the currents from the current modulators (106) and reference voltages is correlated in a way that at least partly cancels the effect of the noise on the delay time.

Abstract: When certain digital circuit devices receive data bus signals, I/O interfaces need to sample the data signals during a time when these signals are both valid and stable. Typically, the data signals are sampled at a time corresponding to a point halfway between rising and falling edges of a reference clock signal associated with the data bus, which sampling time corresponds to a 90-degree phase shift of the reference clock signal. In one embodiment of the invention, a delay count generator determines a delay value corresponding to a quarter cycle (i.e., 90 degrees) of the reference clock signal. In making this determination, a counter counts the number of clock cycles of an internally generated, relatively high-frequency clock signal, where the number corresponds to a specified portion (e.g., one half) of a period of a divided-down version of the reference clock signal. That number can then be used to generate the 90-degree delay value.

Abstract: One embodiment of the present invention sets forth a set of three building block circuits for designing a flexible timing generator for an integrated circuit. The first and second building blocks include delay elements that may be customized and fine-tuned prior to fabrication. The third building block may be tuned prior to fabrication as well as after fabrication. The three building blocks may be incorporated into a modular architecture, enabling designers to easily generate well-characterized, flexible, generic timer circuits.

Abstract: A delaying stage selecting circuit for selecting a specific delaying stage from a plurality of delaying stages, where the delaying stages are for outputting delayed clock signals, includes: a first register for sampling the delayed clock signals according to a clock signal to generate sampled values; first memory units, wherein the first memory units are utilized to memorize the sampled values, and each of first memory unit outputs at least one of the sampled values according to a corresponding first selecting signal; a first selecting unit, for outputting the sampled values according to a second selecting signal; a determining module, for determining if the sampled values meet a specific relation, where if the determination result is positive then determining the particular delaying stage; and a counter for generating a counting value to control the delayed clock signal sampled by the first register.

Abstract: The delay time variation of transistors caused by the manufacturing variation is desired to be adjusted. A relation table storing a relation between sizes and voltage values (supply voltages and bias voltages) is provided. Macros each of which includes a transistor and a setting voltage generation circuit for applying a setting voltage to the transistor are formed on a chip. A process data indicating a size of the transistor is generated. The voltage value corresponding to the size of the transistor indicated by the process data in the relation table is selected as an optimum voltage value (supply voltage Vdd, bias voltage Bias) for each of the macros. The setting voltage of each of the macros is set to the optimum voltage value. The delay time can be adjusted without requiring a detection circuit for detecting the delay time.

Abstract: Using a combination of frequency dithering of a PWM counter and a variable time delay circuit yields improved PWM frequency resolution with realizable circuit components and clock operating frequencies. A controllable time delay circuit lengthens a PWM signal during the first PWM cycle. During the second PWM cycle, the PWM period is increased beyond the desired amount, but the delay is reduced during this second PWM cycle to achieve the correct (desired) PWM signal period. The dithering of the PWM signal period enables the time delay circuit to be “reset” so that an infinite delay circuit is not required. The time delay circuit provides short term (one cycle) frequency adjustment so that the resulting PWM cycle is not dithered and has a period at the desired frequency resolution.

Abstract: Some embodiments provide an integrated circuit (IC) with a delay select input selection circuit. The delay select input selection circuit comprises a first input selection circuit, a first storage element, a second storage element, and a first input line branching into multiple input lines. The multiple input lines include at least a second, third, and fourth input line. The second input line is communicably connected to a first input of the first input selection circuit. The third input line enters the first storage element. The fourth input line enters the second storage element. An output from the first storage element is communicably connected to a second input of the first input selection circuit. An output from the second storage element is communicably connected to a third input of the first input selection circuit.

Abstract: Disclosed is a delay circuit, which comprises: a map delay module, for delaying an input data signal to generate an output data signal according to a mapped delay selection signal; and a delay mapping unit, coupled to the map delay module, for generating the mapped delay selection signal according to an input selection signal and at least a mapping value.

Abstract: A clock network comprises a clock distribution path coupled to a circuit. The clock distribution path and the circuit are formed on a substrate. The clock distribution path comprises a plurality of interconnected elements and one or more disconnected elements. The disconnected elements can be connected to the plurality of interconnected elements after the clock distribution path is tested in connection with the circuit. In one embodiment, the disconnected elements include a capacitor, an interconnect, and a buffer. In an alternative embodiment, the plurality of interconnected elements include a buffer, an interconnect and a capacitor.

Abstract: A clock multiplier includes a phase-frequency detector, a voltage-current converter, a duty ratio control circuit, a plurality of variable delay cells and an edge combiner. The phase-frequency detector generates control signals. The voltage-current converter converts the control signals to generate first and second current control voltages. The duty ratio control circuit modifies the duty ratio of an input clock signal based on the first and second current control voltages. Each of the variable delay cells generates a triangular wave voltage based on the modified input signal, generates a square wave voltage based on the triangular wave voltage to generate a delay signal. The edge combiner generates a plurality of multiplied clocks based on the delay signals from the variable delay cells.

Abstract: A delay circuit includes an interface for giving a command of setting a delay time and a delay device that can be set to any desired delay time, and the delay time of the delay device is set according to a command from the interface.

Abstract: A variable delay apparatus comprises a calibrating unit receiving a signal from a variable delay unit and from a plurality of fixed delay sources, the calibrating unit comparing the signal from the variable delay unit with a plurality of signals from the fixed delay sources to control operation of the variable delay unit over a delay range independently of environmentally-induced drift.

Abstract: An programmable delay apparatus includes a first delay stage having a delay cell which includes a passive network, where the first delay stage is capable of providing a first time delay. The apparatus further includes a second delay stage which includes a plurality of delay cells, where each delay cell is capable of providing a second time delay which is larger than the first time delay. A method for delaying an input signal includes receiving a delay select command based upon the desired time delay, establishing a circuit path which includes at least one delay element, selected from a plurality of delay cells, according to the delay select command, wherein at least one of the plurality of delay cells includes a delay element which comprises a passive network.

Abstract: A hierarchical and modular clock programmable delay circuit structure is described that can achieve almost unlimited fine resolution and unlimited delay range. The same circuit may also be applied to critical circuits that require fine adjustment in timing applications. The modular design allows the circuit and its layout to be synthesized by software to achieve desired delay resolution and range. Constant capacitive load of internal node enhances the linearity of achieved delay by digital controls.

Abstract: A method for glitch-free updates of a standard cell-based programmable delay including the steps of (A) generating an output signal in response to an input signal and a plurality of first control signals and (B) generating the plurality of first control signals in response to the output signal and a plurality of second control signals. The output signal may include a delayed version of the input signal. An amount of delay between the input signal and the output signal may be determined based upon the plurality of first control signals.

Abstract: A digital delay architecture and a digital delay method are provided. The digital delay architecture includes at least one shifter, at least one adder connected to the at least one shifter and a plurality of registers storing at least an output of the at least one adder and an original sampled signal. The plurality of registers are selectable to define a fractional delay value.

Abstract: A time delay compensation circuit comprises delay cells having various unit time delays. A delay-locked loop, a type of the time delay compensation circuit, includes a phase detector, a delay line, and a filter unit. The phase detector compares the phase of the external clock signal with that of the feedback clock signal and outputs a phase difference as an error control signal. The delay line includes a plurality of delay cells having various unit time delays. The number of delay cells is adjusted in response to a predetermined shift signal. The delay line receives the external clock signal and outputs an output clock signal, which is obtained by controlling the phase of the external clock signal. The filter unit generates the shift signal, which selects the number of delay cells in the delay line, in response to the error control signal.

Abstract: A delay apparatus, and a delay locked loop circuit and a semiconductor memory apparatus using the same are provided. A delay locked loop circuit includes a register controlled delay part that delays a plurality of clocks input during an initial operation by delay amounts among initial delay amounts to be varied, which are set according to initial state setting signals, and increases or decreases the set delay amounts according to a phase detecting signal after the initial operation, a phase comparator that compares a phase of any one of the plurality of clocks and a phase of any one of the plurality of clocks delayed by the register controlled delay part and outputs the phase detecting signal, and an initial state setting unit that generates the initial state setting signals.

Abstract: A digitally programmable delay circuit comprising a plurality of transistors connected in parallel with each other and to a line carrying a signal having an edge to be delayed. One or more of the transistors are selected by a delay control signal to impose a delay amount to the edge, wherein the delay control signal is based on a desired delay amount and a measure of instantaneous process, voltage and temperature conditions of an integrated circuit in which the plurality of transistors are implemented. A selector circuit is responsive to the delay control signal and converts the delay control signal into one or more transistor selection signals to activate one or more of the plurality of transistors. The plurality of transistors may comprise a first sub-circuit having a plurality of transistors of a first type (e.g., P-type) connected in parallel with each other in a ladder configuration, and a second sub-circuit comprising a plurality of transistors of a second type (e.g.

Abstract: A programmable, electrically alterable (EA) resistor, an integrated circuit (IC) chip including the EA resistor and integrated analog circuits using on-chip EA resistors. Phase change storage media form resistors (EA resistors) on an IC that may be formed in an array of parallel EA resistors to set variable circuit bias conditions for circuits on the IC and in particular, bias on-chip analog circuits. The bias resistance is changed by changing EA resistor phase. Parallel connection of the parallel EA resistors may be dynamically alterable, switching one or more parallel resistors in and out digitally.

Abstract: A digital time delay circuit is provided in which fabrication process variations and temperature effects on the switching threshold level of digital circuits utilized in the timing delay circuits are substantially eliminated.

Abstract: A method and system for using a programmable driver to dynamically adjust the path delay of a circuit. The path delay adjustment circuit in the illustrative embodiments comprises two or more latches, wherein each latch receives a signal, processes the signal, and generates an output. Compare logic connected to the latches compares the outputs to determine whether the outputs are equal. A counter connected to the compare logic increments a present state of code within the counter if the compare logic determines that the outputs are not equal. A controller connected to the counter comprises a decoder which receives the incremented code from the counter and converts the incremented code to thermometer code. The controller uses the thermometer code to adjust the drive strength of a driver of at least one of the signals.

Abstract: The present invention provides a delay apparatus for delaying an input signal by a predetermined delay amount, including: a plurality of delay units for respectively delaying the input signal by the predetermined delay amount, each delay unit having a plurality of delay cells for respectively delaying the input signal by a certain delay period; and a sub decoding unit for generating a plurality of sub control signals to each of the delay units according to a first control signal and a selecting signal, wherein only delay cell of all the delay units is outputted at a time according to the sub controls signals.

Abstract: A hierarchical and modular clock programmable delay circuit structure is described that can achieve almost unlimited fine resolution and unlimited delay range. The same circuit may also be applied to critical circuits that require fine adjustment in timing applications. The modular design allows the circuit and its layout to be synthesized by software to achieve desired delay resolution and range. Constant capacitive load of internal node enhances the linearity of achieved delay by digital controls.

Abstract: A semiconductor circuit allows a timing adjustment after detailed routing without rearrangement and rerouting, an adjustment of delay variance due to process variation, and a delay adjustment even after chip formation using a primitive cell with a built-in means for adjusting delay time. The circuit connected between an input pad and an output pad, an operating method for the same, and a delay time control system circuit, which externally adjusts delay time of a plurality of control terminal-equipped/variable capacitance embedded buffers configures a semiconductor circuit. The structure includes: a first buffer connected between the input pad and the output pad; and a plurality of capacitances connectable in parallel between a fixed potential and a current flowing path, which is positioned between the first buffer and the output pad, and that controls connection between each of the plurality of capacitances and the output pad.

Abstract: According to at least one embodiment, a system comprises means for performing an operation utilizing a clock signal. The system further comprises means for supplying a variable operating voltage to the performing means, and means for dynamically varying the frequency of the clock signal responsive to observed changes in the variable operating voltage.

Abstract: There is provided a signal generation circuit for generating an output signal including jitter injected thereto. The signal generation circuit includes a jitter output section that outputs a first jitter signal and a second jitter signal which have different frequencies from each other, a carrier output section that outputs a carrier signal having a frequency positioned in substantially the middle between the frequencies of the first and second jitter signals, and an adding section that adds together the first jitter signal, second jitter signal and carrier signal so as to generate the output signal.

Abstract: An adjustable-delay filter performs wave shaping to emulate pre-emphasis or de-emphasis of transmission-line signals. The adjustable-delay filter uses analog components and does not need a clock. The receiver does not have to recover a bit-clock from the data stream, eliminating a clock recovery circuit. An input buffer receives the input signal and drives current to a summer and to an adjustable delay. The adjustable delay inverts and delays the current and drives a delayed, inverted current to the summer. The summer combines the delayed, inverted current and the current from the input buffer to generate an output signal. The delay time of the adjustable delay can be programmed by a user and is less than the bit period. After a signal transition, the output signal initially spikes higher, then falls back to a nominal level after the delay time has expired. The initial signal spike emulates de-emphasis or pre-emphasis.

Abstract: A testing procedure for distributed logic circuits that incorporates an efficient utilization of flip-flops to toggle detect for sensing output is discussed. The distributed logic circuit is a phase interpolator or a phase interpolator preceded by a DLL. The testing procedure utilizes enabling one of a plurality of independent programmable current sources and a flip-flop to toggle in response to the enabled current source to indicate a physical connection of the enabled distributed logic circuit current source.

Abstract: A stacked inverter delay chain. The stacked inverter delay chain includes a plurality of stacked inverter delay elements. A switch circuit is included and is coupled to the stacked inverter delay elements and configured to select at least one of the plurality of stacked inverter delay elements to create a delay signal path. The delay signal path has an amount of delay in accordance with a number of stacked inverter delay elements comprising the delay signal path. An input is coupled to a first stacked inverter delay element of the delay signal path to receive an input signal and an output is coupled to the switch circuit and is coupled to the delay signal path to receive a delayed version of the input signal after propagating through the delay signal path.

Abstract: A programmable delay circuit includes a plurality of delay blocks, a plurality of corresponding tri-state drivers and at least one decoder. The delay blocks are connected together so as to form a series chain. Each of the tri-state drivers includes an input connected to an output of a corresponding one of the delay blocks, and a control input adapted to receive one of multiple control signals. The tri-state driver is operative in one of at least a first mode and a second mode as a function of a corresponding one of the control signals. In the first mode, an output signal generated at an output of the tri-state driver is a function of a voltage level at the input of the tri-state driver, and in the second mode the output of the tri-state driver is in a high-impedance state. The output of each of the tri-state drivers is coupled together and forms an output of the programmable delay circuit. The decoder is connected to the plurality of tri-state drivers.

Abstract: A device for setting a clock delay is proposed, wherein delayed output clock signals are generated with the aid of delaying means by delaying an input clock signal. The delaying means are configured to provide several differently delayed clock signals simultaneously. The device is configured to generate the at least one output clock signal depending on the differently delayed clock signals with a settable phase relationship to the non-delayed input clock signal, wherein the phase relationship is settable independently of the delay provided by the delaying means. It is particularly provided that the phase relationship between the delayed output clock signal and the non-delayed input clock signal is automatically controlled to a desired phase relationship independently of the delay supplied by the delaying means.