A current operating characteristic value of a unit of the memory device is identified. An operating characteristic threshold value is identified from a set of operating characteristic thresholds, where the current operating characteristic value satisfies an operating characteristic threshold criterion that is based on the operating characteristic threshold value. A set of write-to-read (W2R) delay time thresholds that corresponds to the operating characteristic threshold value is identified from a plurality of sets of W2R delay time thresholds. Each of the W2R delay time thresholds in the set is associated with a corresponding read voltage level. A W2R delay time threshold associated with a W2R delay time threshold criterion is identified from the set of W2R delay time thresholds, where the W2R threshold criterion is satisfied by a current W2R delay time of the memory sub-system. A read voltage level associated with the identified W2R delay time threshold is identified.

A memory controller component of a memory system stores memory access requests within a transaction queue until serviced so that, over time, the transaction queue alternates between occupied and empty states. The memory controller transitions the memory system to a low power mode in response to detecting the transaction queue is has remained in the empty state for a predetermined time. In the transition to the low power mode, the memory controller disables oscillation of one or more timing signals required to time data signaling operations within synchronous communication circuits of one or more attached memory devices and also disables one or more power consuming circuits within the synchronous communication circuits of the one or more memory devices.

A nonvolatile memory device includes a first memory chip and a second memory chip connected to a controller through the same channel. The first memory chip generates a first signal from a first internal clock signal based on a clock signal received from the controller. The second memory chip generates a second signal from a second internal clock signal based on the clock signal, and performs a phase calibration operation on the second signal on the basis of a phase of the first signal by delaying the second internal clock signal based on a phase difference between the first and second signals.

A memory component includes a memory core comprising dynamic random access memory (DRAM) storage cells and a first circuit to receive external commands. The external commands include a read command that specifies transmitting data accessed from the memory core. The memory component also includes a second circuit to transmit data onto an external bus in response to a read command and pattern register circuitry operable during calibration to provide at least a first data pattern and a second data pattern. During the calibration, a selected one of the first data pattern and the second data pattern is transmitted by the second circuit onto the external bus in response to a read command received during the calibration. Further, at least one of the first and second data patterns is written to the pattern register circuitry in response to a write command received during the calibration.

Apparatus and methods for operation of a memory controller, memory device and system are described. During operation, the memory controller transmits a read command which specifies that a memory device output data accessed from a memory core. This read command contains information which specifies whether the memory device is to commence outputting of a timing reference signal prior to commencing outputting of the data. The memory controller receives the timing reference signal if the information specified that the memory device output the timing reference signal. The memory controller subsequently samples the data output from the memory device based on information provided by the timing reference signal output from the memory device.

A memory device to program a group of memory cells to store multiple bits per memory cell. Each bit per memory cell in the group from a page. After determining a plurality of read voltages of the group of memory cells, the memory device can read the multiple pages of the group using the plurality of read voltages. For each respective page in the multiple pages, the memory device can determine a count of first memory cells in the respective page that have threshold voltages higher than a highest read voltage, among the plurality of read voltages, used to read the respective page. The count of the first memory cells can be compared with a predetermined range of a fraction of memory cells in the respective page to evaluate the plurality of read voltages (e.g., whether any of the read voltages is in a wrong voltage range).

A memory device of a memory module includes a CA buffer that receives a command/address (CA) signal through a bus shared by a memory device different from the memory device of the memory module, and a calibration logic circuit that identifies location information of the memory device on the bus. The memory device recognizes its own location on a bus in a memory module to perform self-calibration, and thus, the memory device appropriately operates even under an operation condition varying depending on a location in the memory module.

There are provided a memory device for supporting a command bus training (CBT) mode and a method of operating the same. The memory device is configured to enter a CBT mode or exit from the CBT mode in response to a logic level of a first data signal, which is not included in second data signals, which are in one-to-one correspondence with command/address signals, which are used to output a CBT pattern in the CBT mode. The memory device is further configured to change a reference voltage value in accordance with a second reference voltage setting code received by terminals associated with the second data signals, to terminate the command/address signals or a pair of data clock signals to a resistance value corresponding to an on-die termination (ODT) code setting stored in a mode register, and to turn off ODT of data signals in the CBT mode.

A data receiving circuit includes: a first amplification module configured to receive a data signal and a reference signal, compare the data signal and the reference signal in response to a first sampling clock signal, and output a first voltage signal and a second voltage signal; a decision feedback control module configured to generate a second sampling clock signal in response to the enable signal; a decision feedback equalization module configured to, when the enable signal is in a first level value interval, perform decision feedback equalization in response to the second sampling clock signal and stop performing the decision feedback equalization when the enable signal is in a second level value interval; and a second amplification module configured to process the first voltage signal and the second voltage signal and output the first output signal and the second output signal.

Methods for improving timing in memory devices are disclosed. A method may include sampling a command signal according to a clock signal to obtain standard-timing commands. The method may also include sampling the command signal according to an adjusted clock signal to obtain time-adjusted commands. The method may also include comparing the standard-timing commands and the time-adjusted commands. The method may also include determining an improved timing for the clock signal based on the comparison of the standard-timing commands and the time-adjusted commands. The method may also include adjusting the clock signal based on the improved timing. Associated systems and methods are also disclosed.