Abstract: A clock recovery system includes: a sampler that samples reception data with 2N phase clocks and outputs 2N×M sampling signals; a data selector that selects n×M recovery signals from the 2N×M sampling signals and outputs the n×M recovery signals; a phase comparator that outputs, for each of the n×M recovery signals, a phase comparison signal based on the recovery signal, a first sampling signal sampled with a first clock that leads by one or more phases from a sampling clock, and a second sampling signal sampled with a second clock that delays by one or more phases from the sampling clock; a controller that designates n based on a data rate of the reception data; and a multiphase clock generator that generates and outputs the 2N phase clocks based on the phase comparison signal and n.

Abstract: A noise cancelling circuit includes: a first parallel-serial conversion circuit which converts inputted 2N-bit parallel data into serial data; an inverting circuit which inverts one of odd-numbered bits and even-numbered bits included in the inputted 2N-bit parallel data; a second parallel-serial conversion circuit which converts, into serial data, parallel data outputted by the inverting circuit and parallel data of the other one of the odd-numbered bits and the even-numbered bits included in the inputted 2N-bit parallel data which were not inverted; a first buffer which receives output data of the first parallel-serial conversion circuit; and a second buffer which receives output data of the second parallel-serial conversion circuit.

Abstract: A noise cancelling circuit includes: a first parallel-serial conversion circuit which converts inputted 2N-bit parallel data into serial data; an inverting circuit which inverts one of odd-numbered bits and even-numbered bits included in the inputted 2N-bit parallel data; a second parallel-serial conversion circuit which converts, into serial data, parallel data outputted by the inverting circuit and parallel data of the other one of the odd-numbered bits and the even-numbered bits included in the inputted 2N-bit parallel data which were not inverted; a first buffer which receives output data of the first parallel-serial conversion circuit; and a second buffer which receives output data of the second parallel-serial conversion circuit.

Abstract: A clock recovery system includes: a sampler that samples reception data with 2N phase clocks and outputs 2N×M sampling signals; a data selector that selects n×M recovery signals from the 2N×M sampling signals and outputs the n×M recovery signals; a phase comparator that outputs, for each of the n×M recovery signals, a phase comparison signal based on the recovery signal, a first sampling signal sampled with a first clock that leads by one or more phases from a sampling clock, and a second sampling signal sampled with a second clock that delays by one or more phases from the sampling clock; a controller that designates n based on a data rate of the reception data; and a multiphase clock generator that generates and outputs the 2N phase clocks based on the phase comparison signal and n.

Abstract: A timing recovery circuit includes a clock generation circuit which generates clock signals having different periods in different modes, i.e., a first and a second operation mode, phase interpolation circuits each of which outputs a sample timing signal having a phase adjusted to fall between the phases of two clock signals in the first operation mode, and outputs one of the two clock signals as a sample timing signal in the second operation mode, sampler circuits which latch a data signal using the sample timing signals, and a phase control circuit which gives an instruction to select a clock signal or adjust the phase of a sample timing signal.

Abstract: A timing recovery circuit includes a clock generation circuit which generates clock signals having different periods in different modes, i.e., a first and a second operation mode, phase interpolation circuits each of which outputs a sample timing signal having a phase adjusted to fall between the phases of two clock signals in the first operation mode, and outputs one of the two clock signals as a sample timing signal in the second operation mode, sampler circuits which latch a data signal using the sample timing signals, and a phase control circuit which gives an instruction to select a clock signal or adjust the phase of a sample timing signal.

Abstract: A semiconductor device includes a latch circuit. The latch circuit includes a sampling section that latches a differential input signal applied from a differential input node to the gates of a differential pair of transistors, a common adjusting section that adjusts a common potential of the differential input signal by adjusting based on a current control signal the amount of current that is drawn from the differential input node, and a common control section that controls the current control signal so that the differential pair of transistors operate in a saturated region, and supplies the controlled current control signal to the common adjusting section.

Abstract: A phase comparison circuit outputs a first phase comparison signal indicating whether or not an edge of an equalization signal is in a first interval between sampling timing and timing having a first predetermined phase advance, and outputs a second phase comparison signal indicating whether or not the edge of the equalization signal is in a second interval between the sampling timing and timing having a second predetermined phase delay. A determination circuit compares a predetermined comparison target pattern with output patterns of the first and second phase comparison signals corresponding to each bit of a detection data pattern.

Abstract: A comparison period detecting unit (11) defines, as a comparison period, a period between a rising edge of a first clock signal and a rising edge of a second clock signal, and detects the presence or absence of transition of a data signal during the comparison period. A phase relationship detecting unit (12) detects a phase relationship between the data signal and a reference clock signal, and outputs a result of detection of the phase relationship when the comparison period detecting unit (11) detects transition of the data signal during the comparison period.

Abstract: An output circuit (12) converts a pair of current signals supplied to a pair of common nodes (NCa and NCb) into a pair of voltage signals (VOa and VOb). In each of input buffer circuits (11, 11, . . . ), a constant current generation section (101) generates, in an output mode, a pair of constant currents in a pair of current paths going from a pair of intermediate nodes (NMa and NMb) to a reference node (VDD1), and stops the generation of the pair of constant currents in a cutoff mode. A voltage-to-current conversion section (102) generates, in the output mode, a pair of input currents corresponding to a pair of input signals (Sa and Sb) in a pair of current paths going from the pair of intermediate nodes (NMa and NMb) to a reference node (GND) to thereby generate a pair of current signals (Ia and Ib) in a pair of current paths going from the pair of intermediate nodes (NMa and NMb) to the pair of common nodes (NCa and NCb), and stops the generation of the pair of input currents in the cutoff mode.

Abstract: An output circuit (12) converts a pair of current signals supplied to a pair of common nodes (NCa and NCb) into a pair of voltage signals (VOa and VOb). In each of input buffer circuits (11, 11, . . . ), a constant current generation section (101) generates, in an output mode, a pair of constant currents in a pair of current paths going from a pair of intermediate nodes (NMa and NMb) to a reference node (VDD1), and stops the generation of the pair of constant currents in a cutoff mode. A voltage-to-current conversion section (102) generates, in the output mode, a pair of input currents corresponding to a pair of input signals (Sa and Sb) in a pair of current paths going from the pair of intermediate nodes (NMa and NMb) to a reference node (GND) to thereby generate a pair of current signals (Ia and Ib) in a pair of current paths going from the pair of intermediate nodes (NMa and NMb) to the pair of common nodes (NCa and NCb), and stops the generation of the pair of input currents in the cutoff mode.

Abstract: A comparison period detecting unit (11) defines, as a comparison period, a period between a rising edge of a first clock signal and a rising edge of a second clock signal, and detects the presence or absence of transition of a data signal during the comparison period. A phase relationship detecting unit (12) detects a phase relationship between the data signal and a reference clock signal, and outputs a result of detection of the phase relationship when the comparison period detecting unit (11) detects transition of the data signal during the comparison period.