Abstract: A data receiver includes: a plurality of reception circuits each of which receives a data signal through a transmission line, and includes an equalizer having a function of performing waveform shaping of the data signal; and an equalizer adapter which is arranged in correspondence with all or every predetermined number of ones of the plurality of reception circuits, and calculates equalization coefficients for the equalizer in each of the plurality of reception circuits corresponding to the equalizer adapter, where the predetermined number is two or greater.

Abstract: An adaptive equalizer circuit equipped by a control unit for controlling an equalizer circuit, comprising a detection unit for detecting an identity of a preset data pattern with a data pattern as a result of data judgment for an output of the equalizer circuit, a monitor unit for sequentially monitoring an input to a gain amplifier for each of a plurality of filters constituting the equalizer circuit and an output thereof every time the identity detection unit detects an identity, and a unit for making the control unit operate an adaptive equalization control by providing the control unit with the monitoring result, thereby making it possible to track a great change in a characteristic of transmission line without using a matrix responding to the characteristic of the transmission line or a convolution operation by using the matrix.

Abstract: A clock recovery circuit has a boundary detection circuit detecting a boundary in an input signal in accordance with a first signal, and performs recovery of a clock by controlling the timing of the first signal in accordance with the detected boundary. The clock recovery circuit has a boundary detection timing varying circuit and a variation reducing circuit. The boundary detection timing varying circuit dynamically varies boundary detection timing in the boundary detection circuit by applying a variation to the first signal, and the variation reducing circuit reduces a phase variation occurring in the recovered clock in accordance with the dynamic variation of the boundary detection timing performed by the boundary detection timing varying circuit.

Abstract: There are provided a peaking detection part detecting a peaking amount in an output part of an inductor peaking circuit and a control signal generation part varying a circuit parameter of the inductor peaking circuit based on the peaking amount detected by the peaking detection part. Particularly, the inductor peaking circuit has inductors and resistors inserted in series between the output part and a power supply, and capacitances coupled in parallel between the output part and an earth (GND), and depending on respective values of these inductors, resistors and capacitances, it is possible to suppress a peaking generated in the output part.

Abstract: A semiconductor integrated circuit device has a command decoder for issuing a control command in accordance with a supplied control signal, a DRAM core, and a timing adjusting circuit for supplying the control command, set active for a predetermined period, as a DRAM control signal to the DRAM core. The timing adjusting circuit generates n different clocks that are respectively shifted in phase with respect to a supplied reference clock, and generates the DRAM control signal by setting the control command active in a prescribed operation cycle for only a period starting at a first predetermined clock pulse of a first clock of the n clocks and ending at a second predetermined clock pulse of a second clock of the n clocks. In this way, timing design with relatively high accuracy of adjustment can be done in a short period.

Abstract: A first frequency dividing circuit and a second frequency dividing circuit are provided, and these circuits frequency-divide two-phase external clocks injected from an external part, to output four-phase clocks with phase guarantee. Each of the frequency dividing circuits includes a mixer, an adding circuit, and a phase circuit. The first frequency dividing circuit and the second frequency dividing circuit are coupled in loop shape via a first coupling circuit and a second coupling circuit. The first coupling circuit receives a first output signal of the first frequency dividing circuit to output a second external input signal to the second frequency dividing circuit, and the second coupling circuit receives a second output signal of the second frequency dividing circuit to output a first external input signal to the first frequency dividing circuit, and a clock frequency dividing circuit with a high loop gain and a wide lock range can be realized.

Abstract: A clock distribution circuit for suitably generating, transmitting, and receiving clock signals used in circuits that are configured with the same circuit topology is provided. The clock distribution circuit has a transmission buffer circuit that transmits a clock signal and an amplitude amplification buffer circuit that amplifies the amplitude of cross-coupling connections inserted in parallel with the transmission buffer circuit on a transmission path for the clock signal. Wherein the number of transistors having the same conductivity type as the transistors of a differing conductivity type of the transmission buffer circuit and that of the transistors of a differing conductivity type of the amplitude amplification buffer circuit are the same. At least one transistor is provided as a bias adjustment transistor for adjusting bias in each of the transmission buffer circuit and the amplitude amplification buffer circuit, respectively, and bias adjustments are made simultaneously.

Abstract: LC resonant voltage control oscillators are adopted as voltage control oscillators for the purpose of providing a clock generating and distributing apparatus that can generate and distribute a clock signal of high precision even in a high-frequency region of several giga hertz or higher, and of providing a distributive VCO-type clock generating and distributing apparatus in which voltage control oscillators oscillate in the same phase, and which can generate a clock signal of a desired frequency and distributes a high-frequency clock signal to each part within a chip more stably even in a high-frequency region reaching 20 GHz. Furthermore, an inductor component of a wire connecting the oscillation nodes of the oscillators is made relatively small, or the LC resonant oscillators are oscillated in synchronization by using injection locking, whereby the LC resonant voltage control oscillators stably oscillate in the same phase.

Abstract: A clock distribution circuit for suitably generating, transmitting, and receiving clock signals used in circuits that are configured with the same circuit topology is provided. The clock distribution circuit has a transmission buffer circuit that transmits a clock signal and an amplitude amplification buffer circuit that amplifies the amplitude of cross-coupling connections inserted in parallel with the transmission buffer circuit on a transmission path for the clock signal. Wherein the number of transistors having the same conductivity type as the transistors of a differing conductivity type of the transmission buffer circuit and that of the transistors of a differing conductivity type of the amplitude amplification buffer circuit are the same. At least one transistor is provided as a bias adjustment transistor for adjusting bias in each of the transmission buffer circuit and the amplitude amplification buffer circuit, respectively, and bias adjustments are made simultaneously.

Abstract: In order to provide a timing adjustment circuit capable of transmitting/receiving data without being affected by process unevenness and power voltage/temperature fluctuations even at a high data transfer rate, the phase of data outputted by a data transmitting unit is compared with the phase of a clock for regulating a data receiving timing of a data receiving unit, and the phase of a clock for regulating a data transmitting timing of the data transmitting unit is adjusted according to the comparison result.

Abstract: A data receiver includes: a plurality of reception circuits each of which receives a data signal through a transmission line, and includes an equalizer having a function of performing waveform shaping of the data signal; and an equalizer adapter which is arranged in correspondence with all or every predetermined number of ones of the plurality of reception circuits, and calculates equalization coefficients for the equalizer in each of the plurality of reception circuits corresponding to the equalizer adapter, where the predetermined number is two or greater.

Abstract: An adaptive equalizer circuit equipped by a control unit for controlling an equalizer circuit, comprising a detection unit for detecting an identity of a preset data pattern with a data pattern as a result of data judgment for an output of the equalizer circuit, a monitor unit for sequentially monitoring an input to a gain amplifier for each of a plurality of filters constituting the equalizer circuit and an output thereof every time the identity detection unit detects an identity, and a unit for making the control unit operate an adaptive equalization control by providing the control unit with the monitoring result, thereby making it possible to track a great change in a characteristic of transmission line without using a matrix responding to the characteristic of the transmission line or a convolution operation by using the matrix.

Abstract: A step response of a clock synchronous circuit including a bandwidth restriction effect of a transmission path is extracted from circuit data on a simulation subject. A second discrete time model is generated by applying the response function to a first discrete time model generated from the circuit data. Using the second discrete time model, clock edge timing and an effective signal value of a signal input to/output from the clock synchronous circuit at this timing are calculated for simulation execution. Analogically accurate simulation of a circuit operation around a sampling edge of a clock enables precise simulation with a minimum calculation in a short time. Accordingly, the invention can provide an accurate simulation method for accurately modeling an analog operation of a signal transmission circuit that inputs and outputs a high-speed signal, to calculate in a short time.

Abstract: A clock generator supplies a clock signal to a data transmission circuit for a jitter resistance test of a data transmission/reception circuit, while supplying a clock signal to a data reception circuit. At this time, the clock signal supplied by the clock generator to the data transmission circuit is allowed to include jitter of the modulation frequency and depth based on various types of setting signals. A signal is at the H level during the test.

Abstract: A clock recovery circuit has a boundary detection circuit detecting a boundary in an input signal in accordance with a first signal, and performs recovery of a clock by controlling the timing of the first signal in accordance with the detected boundary. The clock recovery circuit has a boundary detection timing varying circuit and a variation reducing circuit. The boundary detection timing varying circuit dynamically varies boundary detection timing in the boundary detection circuit by applying a variation to the first signal, and the variation reducing circuit reduces a phase variation occurring in the recovered clock in accordance with the dynamic variation of the boundary detection timing performed by the boundary detection timing varying circuit.