A method of operating a memory device including receiving a multilevel signal having M levels transmitted by an external controller through a clock receiving pin, where M is a natural number greater than 2, and decoding the multilevel signal to restore at least one of Data Bus Inversion (DBI) data, Data Mask (DM) data, Cyclic Redundancy Check (CRC) data, or Error Correction Code (ECC) data may be provided. The multilevel signal is a clock signal transmitted by the external controller, and is a signal swinging based on an intermediate reference signal that is an intermediate value between a minimum level and a maximum level among the M levels.

Methods, systems, and devices for multi-driver signaling are described. An apparatus may include a first voltage source configured to supply a positive voltage and a second voltage source configured to supply a negative voltage. The apparatus may also include a first driver configured to couple a transmission line of a bus with the first voltage source and a second driver configured to couple the transmission line of the bus with the second voltage source. The first driver may be configured to transfer current to the transmission line based on a configurable resistance of the first driver. And the second driver configured to transfer current from the transmission line of the bus based on a configurable resistance of the second driver.

A multi-level signal receiver includes a data sampler circuit and a reference voltage generator circuit. The data sampler includes (M−1) sense amplifiers which compare a multi-level signal having one of M voltage levels different from each other with (M−1) reference voltages. The data sampler generates a target data signal including N bits, M is an integer greater than two and N is an integer greater than one. The reference voltage generator generates the (M−1) reference voltages, At least two sense amplifiers of the (M−1) sense amplifiers have different sensing characteristics.

This document describes apparatuses and techniques for implementing data masking with pulse amplitude modulation (PAM) encoded signals of a memory circuit. In various aspects, a data mask function of a memory controller may use an unassigned or prohibited PAM signaling state for a set of data lines to indicate data masking to a memory device for a group of data bits. For example, the data mask function may alter a PAM symbol or signal level for at least one data line from a low-voltage state (L) or mid-voltage state (M) state to a high-voltage state (H), resulting in a PAM signaling state for the set of data lines that corresponds data mask indication for the group of data bits. By so doing, the data mask function may indicate data masking for the group of bits without a dedicated data mask signal line, which may enable improved per-line memory bandwidth.

A method of generating a multi-level signal having one of three or more voltage levels that are different from each other, the method including: performing a first voltage setting operation in which first and second voltage intervals are adjusted to be different from each other, wherein the first voltage interval represents a difference between a first pair of adjacent voltage levels and the second voltage interval represents a difference between a second pair of adjacent voltage levels; performing a second voltage setting operation in which a voltage swing width is adjusted, the voltage swing width representing a difference between a lowest and a highest voltage level among the three or more voltage levels; and generating an output data signal that is the multi-level signal based on input data including two or more bits, a result of the first voltage setting operation and a result of the second voltage setting operation.

Methods, systems, and devices for buffer configurations for communications between memory dies and a host device are described. A memory device may include a buffer having a first interface coupled with a host device and a second interface coupled with a memory die of the memory device. The first interface may communicate information with the host device at a first frequency and according to a first signaling scheme, and the second interface may communicate information with the memory die at a second frequency and according to a second signaling scheme. The first frequency may be higher than the second frequency, and the second signaling scheme may include a greater quantity of voltage levels than the first signaling scheme.

A method of generating a multi-level signal having one of three or more voltage levels that are different from each other, the method including: performing a first voltage setting operation in which first and second voltage intervals are adjusted to be different from each other, wherein the first voltage interval represents a difference between a first pair of adjacent voltage levels and the second voltage interval represents a difference between a second pair of adjacent voltage levels; performing a second voltage setting operation in which a voltage swing width is adjusted, the voltage swing width representing a difference between a lowest and a highest voltage level among the three or more voltage levels; and generating an output data signal that is the multi-level signal based on input data including two or more bits, a result of the first voltage setting operation and a result of the second voltage setting operation.

A multi-level signal transmitter includes a voltage selection circuit, which is configured to select one amongst a plurality of driving voltages, which have different voltage levels, in response to input data including at least two bits of data therein. A driver circuit is also provided, which is configured to generate an output data signal as a multi-level signal, in response to the selected one of the plurality of driving voltages. This selected signal is provided as a body bias voltage to at least one transistor within the driver circuit. This driver circuit may include a totem-pole arrangement of first and second MOS transistors having respective first and second body bias regions therein, and at least one of the first and second body bias regions may be responsive to the selected one of the plurality of driving voltages.

A data transmission method for transmitting a data signal using four data signal levels during a unit interval and transmitting a data bus inversion (DBI) signal using two DBI signal levels during the unit interval, the method including: receiving n (n is a natural number) data, each of the n data including a first bit and a second bit; counting the number of data in which the first bit and the second bit have the same value among the n data; in response to the counting result being less than or equal to a predetermined number, transmitting the n data using the four data signal levels, together with a DBI signal having a first DBI signal level; and in response to the counting result being greater than the predetermined number, transmitting data, which is obtained by changing a value of either of the first bit and the second bit of the n data, using the four data signal levels, together with a DBI signal having a second DBI signal level different from the first DBI signal level.

A memory device includes: a memory cell array; a data selector configured to receive data from the memory cell array, and to output the received data as first sub-data and second sub-data; a cyclic redundancy check (CRC) generator configured to generate first CRC values corresponding to the first sub-data, and to generate second CRC values corresponding to the second sub-data; a CRC selector configured to determine an order of the first CRC values and the second CRC values, and to output one of the first CRC values and one of the second CRC values according to the determined order; and a transmitter configured to receive the first CRC values and the second CRC values according to the determined order, and to transmit CRC values of the data by a multilevel signaling method.