Abstract: A memory device includes a first on-die termination circuit, a second on-die termination circuit, a voltage generator, and a code generator. The first on-die termination circuit may correspond to a data input buffer. The second on-die termination circuit may correspond to a command/address buffer. The voltage generator may generate a reference voltage. The code generator may generate a resistance calibration code of a selected one of the on-die termination circuits in response to the reference voltage. The reference calibration code may calibrate a resistance value of the selected on-die termination circuit.

Abstract: Provided is a delay-locked loop circuit for providing a delay-locked clock signal to a data output buffer, the delay-locked loop circuit including: a first delay-locked-mode-based selector configured to select, as a first selected clock signal, one of a first divided clock signal, which is obtained by dividing a reference clock signal by N, and the reference clock signal; and a delay-locked mode controller configured to determine a delay-locked mode on the basis of a command received from the outside and to control the first delay-locked-mode-based selector according to the delay-locked mode. The delay-locked clock signal is generated by comparing a phase of a feedback clock signal generated from the first selected clock signal with a phase of the reference clock signal.

Abstract: Provided is a semiconductor device comprising a signal generator that generates a differential data strobe signal, and a converter that extends a length of a postamble section of the differential data strobe signal from a first length to a second length, wherein the differential data strobe signal enters a high impedance state after the postamble section.

Abstract: A memory module includes a first memory device including a first one-die termination circuit for impedance matching of a signal path and a second memory device sharing the signal path with the first memory device and including a second on-die termination circuit for impedance matching of the signal path, wherein the signal path corresponds to a command or address signal path provided from a host, and the first and second on-die termination circuits are individually controlled according to control of the host.

Abstract: Provided is a delay-locked loop circuit for providing a delay-locked clock signal to a data output buffer, the delay-locked loop circuit including: a first delay-locked-mode-based selector configured to select, as a first selected clock signal, one of a first divided clock signal, which is obtained by dividing a reference clock signal by N, and the reference clock signal; and a delay-locked mode controller configured to determine a delay-locked mode on the basis of a command received from the outside and to control the first delay-locked-mode-based selector according to the delay-locked mode. The delay-locked clock signal is generated by comparing a phase of a feedback clock signal generated from the first selected clock signal with a phase of the reference clock signal.

Abstract: Provided are a reference voltage training device and a method thereof. The reference voltage training device includes a comparator configured to compare a toggle signal with a reference voltage and output a comparison signal, a duty cycle detector configured to check a duty ratio of the comparison signal, and a reference voltage level changing unit configured to fix the reference voltage when the duty ratio meets a predetermined condition and to change a level of the reference voltage when the duty ratio does not meet the predetermined condition. The comparator outputs a changed comparison signal using the changed reference voltage.

Abstract: A semiconductor memory device comprising of a parity check unit configured to receive a command signal and a parity signal to perform error checking in the command signal and output a parity indication signal; a delay unit including a plurality of registers configured to time delay by n clock cycles the parity indication signal and output a delayed parity indication signal; a command register configured to time delay by n clock cycles the command signal and output a delayed command; and a decoder configured to pass or block the delayed command signal based on the delayed parity indicator signal.

Abstract: Provided is a semiconductor device comprising a signal generator that generates a differential data strobe signal, and a converter that extends a length of a postamble section of the differential data strobe signal from a first length to a second length, wherein the differential data strobe signal enters a high impedance state after the postamble section.

Abstract: Provided are a reference voltage training device and a method thereof. The reference voltage training device includes a comparator configured to compare a toggle signal with a reference voltage and output a comparison signal, a duty cycle detector configured to check a duty ratio of the comparison signal, and a reference voltage level changing unit configured to fix the reference voltage when the duty ratio meets a predetermined condition and to change a level of the reference voltage when the duty ratio does not meet the predetermined condition. The comparator outputs a changed comparison signal using the changed reference voltage.

Abstract: A clock generation device includes a flip-flop, a clock division unit, and a clock comparator. The flip-flop generates a chip selection signal synchronized with an internal clock signal. The clock division unit generates second divided clock signals based on a first divided clock signal. The clock comparator selects ones of the second divided clock signals based on the chip selection signal. The clock division unit divides the internal clock signal based on the first divided clock signal and the selected one of the second divided clock signals.

Abstract: A clock generation device includes a flip-flop, a clock division unit, and a clock comparator. The flip-flop generates a chip selection signal synchronized with an internal clock signal. The clock division unit generates second divided clock signals based on a first divided clock signal. The clock comparator selects ones of the second divided clock signals based on the chip selection signal. The clock division unit divides the internal clock signal based on the first divided clock signal and the selected one of the second divided clock signals.

Abstract: A semiconductor memory device comprising of a parity check unit configured to receive a command signal and a parity signal to perform error checking in the command signal and output a parity indication signal; a delay unit including a plurality of registers configured to time delay by n clock cycles the parity indication signal and output a delayed parity indication signal; a command register configured to time delay by n clock cycles the command signal and output a delayed command; and a decoder configured to pass or block the delayed command signal based on the delayed parity indicator signal.

Abstract: Exemplary embodiments disclose a command control circuit including a command decoder configured to generate an internal command signal using a chip select (CS) signal and a command signal, and a CS gating logic configured to provide the CS signal to the command decoder, wherein the CS gating logic is further configured to provide the CS signal to the command decoder in response to a clock enable (CKE) signal being at a first level, and block the CS signal from the command decoder in response to the CKE signal being at a second level.

Abstract: A memory controller includes an I/O circuit, a read latency detector and a clock domain synchronizer. The I/O circuit transmits a first signal to a semiconductor memory device, receives a reflected signal returned from the semiconductor memory device, and delays the reflected signal in response to a delay selection signal to generate a second signal. The reflected signal is provided by reflection of the first signal from the semiconductor memory device. The read latency detector generates the first signal in response to a system clock signal, and generates a read latency signal in response to the system clock signal, a hold signal, and the second signal. The clock domain synchronizer generates the delay selection signal and the hold signal in response to the system clock signal and the second signal.

Abstract: A transceiver for controlling a swing width of an output voltage includes a transmitter and a receiver for receiving an output voltage of a transmitter. The transmitter includes a first signal converter that outputs changed data generated by changing a voltage level of data in response to a mode control signal for selecting a test mode or a normal mode, an output voltage control circuit for controlling a voltage level of an output node of the transmitter in response to the changed data, and a first termination circuit for supplying a changed power supply voltage generated by changing a voltage level of a power supply voltage of the output node of the transmitter, or is turned off, in response to a test mode enable signal or the changed data. The receiver includes a second termination circuit that operates as a resistor having a resistance value that varies in response to the test mode enable signal or a test mode disable signal.

Abstract: A transceiver for controlling a swing width of an output voltage includes a transmitter and a receiver for receiving an output voltage of a transmitter. The transmitter includes a first signal converter that outputs changed data generated by changing a voltage level of data in response to a mode control signal for selecting a test mode or a normal mode, an output voltage control circuit for controlling a voltage level of an output node of the transmitter in response to the changed data, and a first termination circuit for supplying a changed power supply voltage generated by changing a voltage level of a power supply voltage of the output node of the transmitter, or is turned off, in response to a test mode enable signal or the changed data. The receiver includes a second termination circuit that operates as a resistor having a resistance value that varies in response to the test mode enable signal or a test mode disable signal.

Abstract: A memory controller includes an I/O circuit, a read latency detector and a clock domain synchronizer. The I/O circuit transmits a first signal to a semiconductor memory device, receives a reflected signal returned from the semiconductor memory device, and delays the reflected signal in response to a delay selection signal to generate a second signal. The reflected signal is provided by reflection of the first signal from the semiconductor memory device. The read latency detector generates the first signal in response to a system clock signal, and generates a read latency signal in response to the system clock signal, a hold signal, and the second signal. The clock domain synchronizer generates the delay selection signal and the hold signal in response to the system clock signal and the second signal.