Abstract: A phase-combining circuit for combining cyclic timing waveforms that have been phase-controlled by control signals based on three or more input signals of different phases, has a weight signal generating circuit and a weighting circuit. The weight signal generating circuit generates weights according to the control signals, and the weighting circuit gives the weights to the respective input signals, with a positive or negative polarity for each one signal.

Abstract: A data recovery circuit includes an analog-digital converter creating a digital code sequence, a phase detector calculating a position of a crossing point from the digital code sequence, a phase estimator acquiring a presumed position of a data center point of a data sequence based on the position of the crossing point, and a data determining circuit extracting the sequence of data determination values from the digital code sequence based on the position of the crossing point and the presumed position of the data center point.

Abstract: An AD converter includes a first amplitude circuit, a second amplitude circuit, and a determination circuit. A control signal line controls a first amplitude gain of the first amplitude circuit and a second amplitude gain of the second amplitude circuit.

Abstract: A receiver circuit includes: an equalization circuit that equalizes a first signal to obtain a second signal, and adjusts a characteristic of an equalization in accordance with an error between the second signal and a third signal; and a first offset adjustment circuit that adjusts an offset of the first signal in accordance with an error signal indicating the error.

Abstract: An input and output circuit apparatus includes a signal generating circuit configured to generate a first signal, an input and output circuit configured to receive the first signal from the signal generating circuit and a second signal to generate an output signal responsive to the first signal and the second signal, an operation test circuit having substantially an identical circuit configuration to the input and output circuit, and configured to receive the first signal from the signal generating circuit and a third signal to generate an output signal responsive to the first signal and the third signal, a check circuit configured to generates a check signal indicative of an operating condition of the operation test circuit in response to the output signal of the operation test circuit, and an adjustment circuit configured to adjust the signal generating circuit in response to the check signal output from the check circuit.

Abstract: A receiver that receives a train of a plurality of symbols representing digital data, includes: an isolated pulse detector that detects whether the digital data includes an isolated pulse in the symbol train, respectively; a phase detector that detects a timing at which the level of the symbols changes; a symbol value converter that converts the symbols into logical values on the basis of the timing detected by the phase detector; and a data selector that selects a logical value of the isolated pulse instead of the logical value converted by the symbol value converter when the isolated pulse detector detects the digital data containing the isolated pulse.

Abstract: A reception circuit includes: an AD converter; an equalization circuit that equalizes an output of the AD converter; a determination circuit to which error information is input from the equalization circuit; and a controller that adjusts at least one of resolution and voltage range of the AD converter, in the circuit the determination circuit outputs a control signal to adjust at least one of resolution and voltage range to the controller based on the error information.

Abstract: A clock generation circuit includes: a first determination circuit that detects an input signal at a first phase position based on first frequency signal; a second determination circuit that detects the input signal at a second phase position based on second frequency signal; a phase detector that compares output of the first determination circuit and output of the second determination circuit; a first summing circuit which sums comparison result and first control signal; a second summing circuit which sums comparison result and second control signal; a first voltage controlled oscillation circuit which receives output of the first summing circuit and outputs the first frequency signal; a second voltage controlled oscillation circuit which received output of the second summing circuit and outputs the second frequency signal; and a phase adjustment circuit which generates first control signal and second control signal based on first frequency signal and second frequency signal.

Abstract: A reception circuit includes: an AD converter that outputs digital data in accordance with an input signal; a correction circuit that corrects nonlinearity of the AD converter; and an equalization circuit that equalizes the corrected digital data, wherein the correction circuit includes: a conversion table used to convert digital data output from the AD converter; and a correction amount computation circuit that creates the conversion table from the output data of the AD converter and the output of the equalization circuit. The correction amount computation circuit creates the conversion table so that there is no dependence between the ADC output value of the AD converter and the estimation result by the equalization circuit for the ADC output value.

Abstract: A data recovery circuit includes an analog-digital converter creating a digital code sequence, a phase detector calculating a position of a crossing point from the digital code sequence, a phase estimator acquiring a presumed position of a data center point of a data sequence based on the position of the crossing point, and a data determining circuit extracting the sequence of data determination values from the digital code sequence based on the position of the crossing point and the presumed position of the data center point.

Abstract: A signal transmission method suppresses a reflected wave of a transmission signal on a transmission line, by obtaining level and time information related to the reflected wave by computing a correlation between a data pattern of the transmission signal and the reflected wave, and correcting a waveform of the transmission signal based on the level and time information related to the reflected wave.

Abstract: An integrated circuit includes a bypass signal path exchanging, between transceivers which are included in the integrated circuit, a signal transmitted/received between a transceiver of the transceivers and an internal logic circuit which processes data being input/output by transceiver with bypassing the internal logic circuit, a switch switching a pathway of the bypass signal path, and a switch changeover controller transferring a switch control signal that performs a changeover of the switch.

Abstract: An AD converter includes a first amplitude circuit, a second amplitude circuit, and a determination circuit. A control signal line controls a first amplitude gain of the first amplitude circuit and a second amplitude gain of the second amplitude circuit.

Abstract: An integrated circuit chip includes a plurality of two-way transceivers capable of simultaneously transmitting and receiving signals, a switch circuit coupled to the plurality of two-way transceivers and to a given node to provide switchable couplings between the plurality of two-way transceivers and the given node, an interconnection information storage unit to store interconnection information, and a control circuit to set the couplings of the switch circuit in response to the interconnection information.

Abstract: An input and output circuit apparatus includes a signal generating circuit configured to generate a first signal, an input and output circuit configured to receive the first signal from the signal generating circuit and a second signal to generate an output signal responsive to the first signal and the second signal, an operation test circuit having substantially an identical circuit configuration to the input and output circuit, and configured to receive the first signal from the signal generating circuit and a third signal to generate an output signal responsive to the first signal and the third signal, a check circuit configured to generates a check signal indicative of an operating condition of the operation test circuit in response to the output signal of the operation test circuit, and an adjustment circuit configured to adjust the signal generating circuit in response to the check signal output from the check circuit.

Abstract: A clock buffer has a band-pass frequency characteristic, in which a pass band of the buffer includes a fundamental frequency of a clock and a gain for attenuating signals, that is, a gain of less than 0 dB is provided at frequencies below the pass band.

Abstract: A phase-combining circuit for combining cyclic timing waveforms that have been phase-controlled by control signals based on three or more input signals of different phases, has a weight signal generating circuit and a weighting circuit. The weight signal generating circuit generates weights according to the control signals, and the weighting circuit gives the weights to the respective input signals, with a positive or negative polarity for each one signal.

Abstract: A receiver circuit has an equalizer that equalizes a received signal propagating through a transmission medium; a data detection circuit that detects an analog output signal of the equalizer at a data sample timing and outputs a digital signal; an intersymbol interference detection circuit that detects an intersymbol interference level from the analog output signal of the equalizer at the data sample timing and from the digital signal of the data detection circuit; and an equalization characteristic control unit that controls the characteristic of the equalizer to minimize the detected intersymbol interference level. The receiver circuit further has a data sample timing control unit in which the data sample timing is controlled to a sample timing at which the difference between the amplitude of the analog output waveform of the equalizer with respect to an impulse and the amplitude of an ideal impulse response waveform is minimal.

Abstract: A clock buffer has a band-pass frequency characteristic, in which a pass band of the buffer includes a fundamental frequency of a clock and a gain for attenuating signals, that is, a gain of less than 0 dB is provided at frequencies below the pass band.

Abstract: A timing signal generating system has a clock signal generating circuit, a synchronizing circuit, a phase code recognizing circuit, and a calibration circuit. The clock signal generating circuit generates at least one first clock signal upon receipt of at least one reference clock signal by controlling an output phase thereof with a digital code signal. The synchronizing circuit hands over signals between a group of circuits operated by the first clock signal and an internal circuit operated by a second clock signal. The phase code recognizing circuit recognizes a phase code when the phases of the first clock signal and of the second clock signal are in a particular relationship. The calibration circuit calibrates a relationship between a value of the recognized phase code and a phase difference between the first and second clock signals. The synchronizing circuit is controlled by using phase code data calibrated by the calibration circuit.