Abstract: An integrated circuit has a synchronous circuit and an asynchronous circuit. A clock-controlled input register circuit and an output register circuit for storing data are each connected to the synchronous circuit and the asynchronous circuit. Data are transferred from the synchronous circuit into the input register circuit, from where they are transferred into the asynchronous circuit and processed in the asynchronous circuit. Processed data are transferred into the output register circuit. A sequence controller generates a respective control clock signal for the register circuits in a manner dependent on the data processing duration of the asynchronous circuit. This enables a high data throughput between the synchronous circuit and the asynchronous circuit independently of a clock frequency of the synchronous circuit.

Abstract: Devices, circuits and methods for dual voltage generation using a single charge pump. The dual voltages can be the same or different, as they are for two different components of a device. An oscillator generates an oscillating signal, and a charge pump generates a pumping voltage at a pumping node responsive to the oscillating signal. A first switching circuit is coupled to the pumping node, and outputs from the pumping voltage a first voltage to the first component. A second switching circuit is coupled to the pumping node, and outputs from the pumping voltage a second voltage to the second component. The first and second output voltages may optionally be sensed. The oscillator may be triggered and the first and second switching circuits may be controlled as needed to maintain the sensed first and second voltages at desired values and/or ranges.

Abstract: A method is described that involves directing a signal through a hysteresis comparator. Then, determining if an output signal of the hysteresis comparator, in response to the signal, is an AC signal or a DC signal. Then, deactivating a signal reception unit that receives the signal if the hysteresis comparator output signal corresponds to a DC signal; or, activating the signal reception unit if the hysteresis comparator output signal corresponds to an AC signal.

Abstract: A synchronized data capture circuit configured to synchronize capturing of data in a first plurality of data signals with a first plurality of timing signals to output a synchronized data capture signal. The synchronized data capture circuit includes a timer generator having a first timer generator output. The timer generator is coupled to receive the first plurality of timing signals and to serially output on the first timer generator output, as a first high frequency timing pulse stream, first timing pulses responsive to timing pulses of the plurality of timing signals. The first high frequency timing pulse stream has a timing pulse stream frequency that is higher than a timing input frequency associated with one of the first plurality of timing signals. The synchronized data capture circuit also includes first plurality of data driver circuits coupled to receive the first plurality of data signals and the plurality of timing signals.

Abstract: A system and method for reducing timing uncertainties in a serial data signal. A system may comprise a transmitter configured to transmit serial data to a receiver through a transmission medium. The receiver may comprise a retiming mechanism configured to sample the serial data using a particular phase of a clock at a point in time when the serial data signal may not be likely to experience jitter. The retiming mechanism may comprise a plurality of first units, e.g., flip-flops, where each of the first units is configured to sample the serial data using a particular phase of the clock. Each of the first units may be connected to a particular second unit, e.g., transmission gate. Each of the second units may be configured to output the value of the serial data sampled by the associated first unit upon activation. The data outputted may subsequently become part of the retimed data.

Abstract: An electronic circuit that multiplies an input signal using primarily digital components so that the resulting circuit can be fabricated consistently by different foundries. The circuit determines a period for the input signal and converts the period to a digital number (e.g., a binary number). An adder is used to determine an average period over a predetermined number of cycles. By determining the average period, voltage fluctuations are cancelled. A multiplier allows for a variable multiplication of the averaged period. A clock generating circuit uses the results obtained by the multiplier to generate a multiplied output signal. Additionally, the input signal is routinely multiplexed with the generated output signal to ensure phase matching.

Abstract: Intermittent miscounts generated by counters used in a phase-locked loop (“PLL”) are precisely measured by detecting changes to a predetermined waveform, such as a sawtooth waveform. The miscounts are detected using an open loop, not closed loop, set-up which comprises two separate signal generators feeding two separate frequencies into MAIN and REF counters of a PLL. Offsetting the frequencies slightly and integrating an output generates the predetermined waveform. Thereafter, miscounts can be detected by comparing waveforms corresponding to miscounts to theoretically predicted, predetermined waveforms.

Abstract: An output circuit is driven by means of a first differential amplification circuit having an N-channel differential amplification stage that compares a reference voltage VREF with an input signal IN, and a second differential amplification circuit having a P-channel differential stage. An output of the first differential amplification circuit is given as the gate voltage of P-channel MOS transistors in the output circuit, and an output of the second differential amplification circuit is given as the gate voltage of N-channel MOS transistors in the output circuit. This realizes an input buffer with reduced error operations even under threshold voltage variations caused by process variations and others.

Abstract: The semiconductor integrated circuit device of the present invention for accepting an external signal synchronously with an external clock signal, comprises: an internal clock signal circuit for detecting a change in the external clock signal and generating an internal clock signal having a predetermined pulse width; a latch circuit for accepting the external signal in advance and latching the external signal for the period of time corresponding to the predetermined pulse width according to the internal clock signal; and an internal signal generating circuit for generating an internal signal which reflects the logic of the external signal and has the predetermined pulse width, according to the internal clock signal.

Abstract: A hybrid phase locked loop employs both analog and digital circuitry. A digital to analog converter (DAC) provides a current output signal in conjunction with a current controlled oscillator (ICO). The hybrid phase locked loop employs the digital circuitry, among other reasons, to assist in generating an optimal feedback frequency signal before the loop of the hybrid phase locked loop is closed. The hybrid phase locked loop intelligently employs appropriate switching in strategically placed portions of the hybrid phase locked loop to ensure stable operation once the loop of the hybrid phase locked loop is closed. The hybrid phase locked loop employs baseline components in certain embodiments of the invention. These baseline components are those whose component values may vary significantly as a function of operating conditions, environmental perturbations, and which have relatively relaxed tolerances/precisions.

Abstract: The internal clock signal generating circuit of the present invention includes a pulse generation circuit for receiving a reference clock signal which is generated in response to an external clock signal, and generating an internal clock signal. The pulse generation circuit includes a pulse generation unit for generating a pulse signal which is activated in response to a rising edge of a first delay signal obtained by delaying the reference clock signal by a first delay time, and deactivated in response to a falling edge of a second delay signal obtained by delaying the reference clock signal by a second delay time which is shorter than the first delay time, and a driving unit for generating the internal clock signal which is activated in response to a falling edge of the reference clock signal and deactivated in response to a rising edge of the pulse signal.

Abstract: An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate (i) a first signal and a second signal in response to a pump down signal and (ii) a third signal and a fourth signal in response to (i) a pump up signal. The second circuit may be configured to generate (a) a first control signal in response to (i) the first signal and (ii) the third signal and (b) a second control signal in response to (i) the second signal and (ii) the fourth signal.

Abstract: Disclosed is a semiconductor device for outputting an output signal with a given phase held relative to an external clock despite a difference in characteristic, a change in temperature, and a fluctuation in supply voltage. The semiconductor device comprises an input circuit for inputting the external clock and outputting a reference signal, an output circuit for receiving an output timing signal and outputting an output signal according to the timing of the output timing signal, and an output timing control circuit for controlling the output timing so that the output signal exhibits a given phase relative to the external clock.

Abstract: A state machine operates in synchronization with a reference clock signal (110) to switch between n numbers of states and maintain any one of these states. Every time a condition for transition to each of the n numbers of states is satisfied, a signal output circuit (100) makes one of n numbers of transition condition satisfying signals (111W, 111Z, 111Y . . . ) active and outputs it. One of a plurality of D-type flip-flops (101-1, 101-2, 101-k . . . ) makes active any one of nu numbers of state signals (W, Z, Y . . . ) indicating the corresponding n numbers of states, and holds the corresponding one state. A synchronization pulse generation circuit (102) generates a one-shot synchronization pulse signal (112) in synchronization with the reference clock signal (110), when a transition condition for transition to one state is satisfied.

Abstract: A clock control circuit includes a forward pulse delay circuit including a plurality of delay circuits for delaying a forward pulse signal FCL, a backward pulse delay circuit including a plurality of delay circuits for delaying a backward pulse signal RCL, a state-hold section including a plurality of state-hold circuits for controlling the operation of the backward pulse delay circuit in accordance with the transmission condition of the forward pulse signal in the forward pulse delay circuit, and an input stop circuit for stopping inputting a pulse corresponding to an external clock signal to the backward pulse delay circuit during a predetermined period from the time point when the external clock signal begins to be supplied.

Abstract: A 2/N mode clock generator that generates bus clock signals through the use of bus clock enable signals selecting bus clock pulses that are in phase and out of phase with a core clock signal. The clock generator maintains synchronization between the bus clock signal and the core clock signal so that they are always in a predetermined phase relationship.

Abstract: A stable and flexible phase locked loop system and method are disclosed. The system comprises a first phase frequency detector for detecting a difference between an internal clock signal and an external clock signal, and for generating a first control signal representing the difference. A first voltage controlled oscillator coupled to the first phase detector generates a first timing signal based on the first control signal. A first divider circuit coupled to the first voltage controlled oscillator divides the first timing signal by a first predetermined number to provide an output signal. A second phase frequency detector detects a difference between the first timing signal and a second timing signal, to generate a second control signal representing the difference. A second voltage controlled oscillator coupled to said second phase detector generates a third timing signal based on the second control signal.

Abstract: A frequency divider includes a mixer having a first input connectable to a reference oscillator and a second input connectable from the reference oscillator through a frequency synthesizer to the second input of the mixer. The mixer provides an output signal to a filter, which provides a frequency divider output. The frequency synthesizer provides an output signal having a frequency of (N+1)/N or (N-1)/N times the input F.sub.IN from the reference oscillator. With the frequency synthesizer providing the signal F.sub.IN (N+1)/N, or F.sub.IN (N-1)/N, the output of the mixer provides the signal having the frequency F.sub.IN /N and can utilize a single filter to eliminate undesired mixer outputs. Further, the frequency synthesizer can be configured to utilize an oscillator which operates over the same frequency range as the reference oscillator.

Abstract: Multiplexers are used to generate synchronized slave clocks from a common master clock. A first multiplexer and a second multiplexer generate a first slave clock and a second slave clock, respectively, from the common master clock. A third multiplexer and a fourth multiplexer are configured as a divide-by-n circuit for providing a third slave clock that is a divided version of the second slave clock. A fifth multiplexer provides a matching delay to preserve the synchronization between the first slave clock and the other slave clocks. A sixth multiplexer is used to select between the second slave clock and the third slave clock in response to a select signal. A flip-flop may be used to provide the select signal and to guard against false selection of slave clocks.

Abstract: Combinatorial blocks (KBL) are arranged between an input register (RG1) and output register (RG2) in the circuit arrangement. The input (E.sub.-- RG1) and the output (A.sub.-- RG1) of the input register (RG1) connected preceding the combinatorial blocks (KBL) is connected to a comparison unit (COM) that compares the value at the input and at the output of the input register (RG1) and, given occurrence of a signal value change at the input, outputs a control signal for loading the output value of the combinatorial blocks (KBL) into the output register (RG2) connected following the combinatorial blocks. In this way, the running time required for an operation in the circuit arrangement can be shortened given specific value combinations.

Abstract: The ON and OFF states of a second device are controlled by a first device through a three-conductor bus. The bus carries data, clock, and enable signals and the second device is in the OFF state when all the signals of the three-conductor bus have an L level. The second device is in the ON state when at least one of the signals has an H level (higher potential than the L level). The enable signal is set to the H level during the data transmission. Otherwise, it carries an L level, while the data or clock signal has an H level. The system obviates an additional housing pin. The operating state information is transmitted relatively rapidly.

Abstract: A simply structured clock pulse generator operating stably in a wide range of frequencies in response to a timing signal fed from outside a semiconductor integrated circuit. A first frequency signal fed from the external terminal of the semiconductor integrated circuit and a second frequency signal generated within the semiconductor integrated circuit are input to a phase comparator. The output signal of the phase comparator is smoothed by a low-pass filter for conversion to a voltage signal. A compensation circuit uses both a delay signal from a current-controlled delay circuit receiving the first frequency signal and the first frequency signal to generate a current signal corresponding to the frequency of the latter signal. The voltage signal generated by the low-pass filter is converted into a current signal.

Abstract: A clock reproduction circuit for reproducing a data clock from a data signal is disclosed. The clock reproduction circuit includes a voltage controlled oscillator, a phase detector, a frequency error detection circuit and a charge pump whose output is controlled by the outputs of the phase detector and the frequency error detection circuit. A VCO clock output from the voltage controlled oscillator is synchronized with the data clock by the feedback loop consisting of these elements. The frequency error detection circuit detects a frequency error between the VCO clock and the data clock by detecting changes in the phases of the VCO clock at the transition edges of the data signal. Analog and digital frequency error detection circuits are disclosed. Further, improved circuit elements in the clock reproduction circuit are disclosed.

Abstract: A clock circuit for generating alternate clock phases (P.sub.1, P.sub.2) whose trailing edges define sampling points of an analog-to-digital converter (106). Complementary signals (CLOCK0, CLOCK1) are generated from a system clock (F.sub.SYS) and switched through transmission gates (340-341, 342-343) when an enable signal (V.sub.EN) is applied. The system clock (F.sub.SYS) is delayed by a delay circuit (316) to produce the enable signal (V.sub.EN) after the complementary signals (CLOCK0, CLOCK1) are stable, thereby synchronizing the complementary signals (CLOCK0, CLOCK1) with the enable signal (V.sub.EN).

Abstract: A device for deriving a clock signal having a specific frequency, from an electrical signal, for example, a video signal, the device including an input terminal (1) for receiving the synchronizing signal; a phase comparator (5) having a first input coupled to the input terminal, a second input and an output; a voltage controlled oscillator (15) having an input coupled to the output of the phase comparator, and an output; a counter (23) having a first input coupled to the output of the voltage controlled oscillator, a second input for receiving a preset control signal, and an output coupled to the second input of the phase comparator; a preset control signal generator (30) having an input coupled to the input terminal, and an output coupled to the second input of the counter, the counter being adapted to set its count value to a preset value in response to the preset control signal applied to its preset control signal input.

Abstract: A semiconductor device includes a one-shot pulse generating circuit that generates a one-shot pulse having a predetermined pulse width at a rise or fall timing of a first clock signal, a cycle time measuring circuit that measures a cycle time of the first clock signal from the one-shot pulse output from the one-shot pulse generating circuit, an internal clock generating circuit that generates a second clock signal based on the cycle time measured by the cycle time measuring circuit and the one-shot pulse output from the one-shot pulse generating circuit. The second clock signal has a cycle time identical to the first clock signal and has rise or fall timing which is advanced by a specific time than that of the first clock signal, and the specific time is obtained by subtracting the cycle time of the first clock signal from a predetermined time, and a data output circuit that outputs data after a predetermined delay time from the rise or fall timing of the second clock signal.

Abstract: A duty ratio-guaranteed reference clock signal and a duty ratio-unguaranteed drive clock signal serve as input to a clock signal waveform-correcting system in accordance with this invention. The system thereafter puts out a post-correction drive clock signal that is duty ratio-guaranteed. The system has a phase comparator and a switch circuit. The phase comparator puts out a HIGH signal as long as the reference clock signal and the drive clock signal disagree in logical level. The switch circuit transmits an inverted signal as a result of inverting the drive clock signal, to an output signal of a first buffer to which the drive clock signal is applied. A second buffer takes in the output signal and puts out a post-correction drive clock signal.

Abstract: A synchronizer that has reduced latency is used for synchronizing and conditioning a clock-enable signal to a free-running clock. Once the clock-enable signal is synchronized it is used to enable and disable gating of the free-running clock to a gated clock that suspends pulsing in response to the clock-enable signal. A first-stage flip-flop is `meta-stable hardened` to reduce the probability of it becoming meta-stable. Gating on the clock and the clear inputs reduces the chance that simultaneous inputs will violate the timing of the flip-flop and thus cause metastability. A clear pulse is generated to clear the flip-flop. The clear pulse skews the flip-flop to be more likely to become metastable for one edge of the asynchronous input than for the other edge. The settling time to the second stage flip-flop is then adjusted to account for this skew in metastability. Settling time in the second stage is increased for the edge that is more likely to become metastable.

Abstract: In a data transfer system for use in an integrated circuit, a data output circuit comprises a D-FF for latching data to be transferred, in synchronism with an external clock signal, an output buffer receiving and outputting the data latched in the D-FF, and another output buffer receiving the external clock signal for outputting a delayed clock signal which is delayed from the external clock signal by a delay amount of the D-FF. On the other hand, a data input circuit including a first D-FF for receiving the data to be transferred outputted from the D-FF of the data output circuit, in synchronism with the delayed clock signal supplied from the D-FF of the data output circuit, and a second D-FF for fetching the data received in the first D-FF, in synchronism with the external clock signal.

Abstract: A simply structured clock pulse generator operating stably in a wide range of frequencies in response to a timing signal fed from outside a semiconductor integrated circuit. A first frequency signal fed from the external terminal of the semiconductor integrated circuit and a second frequency signal generated within the semiconductor integrated circuit are input to a phase comparator. The output signal of the phase comparator is smoothed by a low-pass filter for conversion to a voltage signal. A compensation circuit uses both a delay signal from a current-controlled delay circuit receiving the first frequency signal and the first frequency signal to generate a current signal corresponding to the frequency of the latter signal. The voltage signal generated by the low-pass filter is converted into a current signal.

Abstract: A fully asynchronous parallel synchronizer having staged write and read enables and an asynchronous interface for same. The asynchronous interface can be used to interconnect two processor systems (e.g., within a multiple processor system or a parallel processor system). The parallel programmable synchronizer contains n latches coupled in parallel having n individual enable lines having staggered enable signals. The latches are coupled such that they output to a multiplexing circuit that also receives individual staggered read enable signals which are based on the write enable signals. According to the parallel programmable synchronizer, data is written into a particular latch in clock cycle (i) just after other data was read from the same particular latch in a just prior clock cycle (i-1). While the synchronizer contains n latches, the number of latches used, x, for any particular embodiment is programmable and the enable signals adjust to accommodate the number of latches selected.

Abstract: A write data precompensator system is described which comprises a delay element circuit (12) which receives a clock signal and outputs a delayed clock signal which includes a programmable selectable delay in the rising edge of the clock signal. The amount of delay is received using a delay voltage level generated by a delay level circuit (16) which receives delay magnitude control values in digital form. A reference level circuit (18) also generates a continuous level voltage level so that the delay element circuit (12) can instantly change between a delayed operation and an undelayed operation without waiting for the delay voltage level to adjust.

Abstract: There is disclosed a horizontal synchronizing signal generating circuit for generating a horizontal synchronizing signal which has no frequency variations and which is in phase with an entered composite synchronizing signal if the entered composite synchronizing signal is a nonstandard signal having a varying horizontal frequency. A horizontal counter circuit (5) counts a reference clock (V.sub.CL), and a window pulse generating circuit (4) outputs a window pulse signal (V.sub.W) which is low for a fixed time period when a counter output (V.sub.CT) equals a counter value (878) indicative of a standard output timing. A horizontal synchronizing signal separating circuit (1) outputs a horizontal synchronizing signal (V.sub.2) only when the composite synchronizing signal (V.sub.1) falls within the fixed time period. Then a horizontal phase judging circuit (2) outputs a standard signal flag (V.sub.3) and a synchronizing signal generating circuit (3) outputs the horizontal synchronizing signal (V.sub.

Abstract: A synchronized clock generating apparatus includes a delayed clock generating circuit including a plurality of serially connected delaying elements for generating delayed clock signals delayed successively to an incoming basic clock signal. A plurality of storage elements store therein a predetermined level in response to transitions occurring in associated ones of the basic and delayed clock signals after an asynchronous trigger signal is applied thereto. A clock selection logic circuit is controlled by the output signal from the storage elements for detecting the clock signal transition occurring closest in time to the application of the asynchronous trigger signal, and for selecting a desired one of the clock signals based on the result of the detection, as a synchronized clock input signal.

Abstract: A rate generating portion generates a second rate signal comprising a desired first rate signal having arbitrary time intervals preceded by a preceding rate signal composed of (N+1) pulses, a data row generating portion composed of N logic circuits and N D-type flip-flops generates an arbitrary data row with the second rate signal as a synchronizing clock, a preceding rate masking circuit masks the preceding rate signal in the second rate signal to output the first rate signal and a D-type flip-flop receives the output of the data row generating portion at the data input terminal thereof and the output of the preceding rate masking circuit at the clock input terminal thereof to generate a data row in synchronism with the first rate signal. As a result, it is possible to provide a synchronous data row generating circuit which operates stably without using the conventional delay elements for adjustment since the data row generating portion therein is composed of synchronous circuits.

Abstract: A synchronized clock generating apparatus includes a delayed clock generating circuit including a plurality of serially connected delaying elements for generating delayed clock signals delayed successively relative to an incoming basic clock signal. Storage means includes a plurality of storage elements storing therein a predetermined level in response to transitions occurring in associated ones of said basic and delayed clock signals after a trigger signal which is asynchronous with the basic clock signal is applied thereto. A clock selection logic circuit is controlled by the output signal of the storage means for detecting the clock signal transition occurring closest in time to the application of the asynchronous trigger signal, and for selecting a desired one of said clock signals, based on the result of the detection, as a synchronized clock signal output.

Abstract: An information processing system comprises a sub-circuits, each performing a part of the processing of the information or data. The operation of the sub-circuits is synchronized by means of clock signals applied to clock inputs of the sub-circuits. The clock signals are derived from a system clock and are transferred to each sub-circuit via the sub-circuit or sub-circuits preceding that sub-circuit in the data processing chain. To avoid deterioration of the clock pulses while they are transferred between the sub-circuits, clock regeneration circuitry is arranged in the chain of sub-circuits. The clock regeneration circuitry is preferably integrated together with the data-processing sub-circuits.

Abstract: A ring oscillator includes an even-numbered plurality of ring coupled delay stages. Each delay stage includes a differential amplifier, a voltage clamping circuit, and a current source. The differential amplifier receives first and second input signals from a preceding delay stage. The differential amplifier provides a first output signal and a complementary second output signal at first and second nodes, respectively. The voltage clamping circuit is coupled between the first and second nodes to limit a peak-to-peak voltage swing of each of the first and second output signals. The current source is coupled to the differential amplifier and varies a bias current in accordance with a delay bias voltage.