An impedance calibration circuit includes a first code generation circuit connected to a first reference resistor, and configured to generate a first code for forming a resistance based on the first reference resistor, by using the first reference resistor; a second code generation circuit configured to form a resistance of a second reference resistor less than the resistance of the first reference resistor, based on the first code, and generate a second code by using the second reference resistor; and a target impedance code generation circuit configured to generate a target impedance code based on the first code, the second code, and a target impedance value, and form an impedance having the target impedance value in a termination driver connected to the impedance calibration circuit, based on the target impedance code.

This document describes apparatuses and techniques for termination for single-ended (SE) mode operation of a memory device. In various aspects, a termination circuit can terminate an unused signal line of a differential pair to a ground or power rail using a switch element when operating in the SE mode. The termination circuit may also disconnect the unused signal line from a first input of a differential amplifier and connect a reference voltage to the first input of the differential amplifier. Based on the reference voltage, the differential amplifier amplifies an SE signal received using another signal line of the differential pair at a second input of the differential amplifier to provide a clock signal for memory operations. Thus, the termination circuit may reduce an amount by which noise associated with the unused signal line affects the differential amplifier when the memory device operates in SE mode.

A device may include a ZQ calibration circuit. The ZQ calibration circuit may include a first register configured to store a first impedance code generated responsive to a ZQ calibration command. The ZQ calibration circuit may also include a second register configured to store a shift value. Further, the ZQ calibration code may include a compute block configured to generate a second impedance code based on the first impedance code and the shift value. Systems and related methods of operation are also described.

Apparatuses and methods for calibrating adjustable impedances of a semiconductor device are disclosed in the present application. An example apparatus includes a register configured to store impedance calibration information and further includes programmable termination resistances having a programmable impedance. The example apparatus further includes an impedance calibration circuit configured to perform a calibration operation to determine calibration parameters for setting the programmable impedance of the programmable termination resistances. The impedance calibration circuit is further configured to program the impedance calibration information in the register related to the calibration operation.

A data input buffer includes a plurality of buffer units configured to receive a first impedance calibration code and a second impedance calibration code, wherein each of the plurality of buffer units outputs an offset detected with a first input terminal and a second input terminal thereof short-circuited, as write data, and wherein a buffer unit corresponding to a current value of the first impedance calibration code among the plurality of buffer units is configured to correct the offset according to the second impedance calibration code.

A processor circuit sends a read request. A clock signal of the processor circuit corresponds to a first counting value. A memory circuit stores data and sends a data strobe signal in response to the read request. The data strobe signal corresponds to a second counting value. The processor circuit includes a selector circuit and a feedback circuit. The selector circuit selects and outputs a flag signal from a plurality of flag control signals according to the second counting value. The feedback circuit generates an enable signal according to a set signal associated with the first counting value, the flag signal associated with the second counting value, and a data strobe gate signal, and generates the data strobe gate signal according to the enable signal and the data strobe signal. The processor circuit reads the data according to the data strobe gate signal.

A method of operating an input/output interface includes selecting one of a plurality of output driver circuits according to a mode selection signal, and outputting a data signal using the selected one of the plurality of output driver circuits. Another method of operating an includes generating a mode selection signal based on a received command signal, and controlling an on-die termination (ODT) circuit included in the input/output interface according to the mode selection signal. Another method of operating an includes generating a mode selection signal based on a received command signal, and controlling an ODT circuit included in the input/output interface according to the mode selection signal.

A level converter and circuit arrangement comprising such level converters. The level converter comprises a transistor, an impedance converter, an input voltage connection, an output voltage connection, and a power supply connection. The input voltage connection is connected to a gate terminal of the transistor. The output voltage connection is connected to a source terminal of the transistor and to the power supply connection. A first input terminal of the impedance converter is connected to the source connection or to the gate terminal of the transistor. An output terminal of the impedance converter is connected to the drain terminal of the transistor. The power supply connection is equipped to receive a current from a constant current source. The impedance converter is equipped to keep a source-drain voltage of the transistor at a predefined value using a reference voltage.

A signal transmitting and receiving apparatus including: a first on-die termination circuit connected to a first pin through which a first signal is transmitted or received and, when enabled, the first on-die termination circuit is configured to provide a first termination resistance to a signal line connected to the first pin; a second on-die termination circuit connected to a second pin through which a second signal is transmitted or received and, when enabled, the second on-die termination circuit is configured to provide a second termination resistance to a signal line connected to the second pin; and an on-die termination control circuit configured to independently control an enable time and a disable time of each of the first on-die termination circuit and the second on-die termination circuit.

Disclosed is a transceiver which includes a logic circuit that generates parallel transmission data in response to a first test mode signal or a second test mode signal, a serializer that converts the parallel transmission data into serial transmission data, a driver that outputs the serial transmission data through transmission pads, an analog circuit that receives serial reception data through reception pads, a deserializer that converts the serial reception data into parallel reception data, a plurality of test switches switched in response to the first test mode signal, and a test circuit that is electrically connected to the analog circuit through the plurality of test switches and outputs serial post data corresponding to the serial transmission data to the analog circuit.