A method includes performing a first write operation that writes data to a first memory unit of a group of memory units in a memory device, determining a write-to-write (W2W) delay based on a time difference between the first write operation and a second write operation on a memory unit in the group of memory units, wherein the second write operation occurred prior to the first write operation, identifying a threshold time criterion that is satisfied by the W2W delay, identifying a first read voltage level associated with the threshold time criterion, and associating the first read voltage level with a second memory unit of the group of memory units. The second memory unit can be associated with a second read voltage level that satisfies a selection criterion based on a comparison of the second read voltage level to the first read voltage level.

Methods, devices, and systems related to storing parity data in dynamic random access memory (DRAM) are described. In an example, a method can include generating, at a controller, parity data based on user data queued for writing to a non-volatile memory device, receiving the parity data at a DRAM device from the controller and writing the parity data to the DRAM device, receiving the user data at a non-volatile memory device from the controller and writing the user data to the non-volatile memory device, reading the user data from the non-volatile memory device via the controller, and receiving the parity data at the controller from the DRAM device.

A semiconductor memory apparatus may include a memory bank, a global buffer array, and an input and output circuit. The memory bank includes a local data circuit, and the global buffer array includes a global data circuit. The local data circuit is operably coupled to the global data circuit. The global buffer array may be operably coupled to the input and output circuit. The memory bank is disposed in a core region, and the global buffer array and the input and output circuit may be disposed in a peripheral region separated from the core region.

A storage device includes 3D NAND including layers of multi-level cells. Test reads are performed by reading only LSB pages and reading layers in a repeating pattern of reading two and skipping two. A test read of a block is performed when its read count reaches a threshold. The counter threshold is updated according to errors detected during the test read such that the frequency of test reads increases with increase in errors detected. Counter thresholds according to errors may be specified in a table. The table may be selected as corresponding to a range of PEC values including the current PEC count of the 3D NAND. Each table further specifies a number of errors that will result in garbage collection being performed.

A storage device includes 3D NAND including layers of multi-level cells. Test reads are performed by reading only LSB pages and reading layers in a repeating pattern of reading two and skipping two. A test read of a block is performed when its read count reaches a threshold. The counter threshold is updated according to errors detected during the test read such that the frequency of test reads increases with increase in errors detected. Counter thresholds according to errors may be specified in a table. The table may be selected as corresponding to a range of PEC values including the current PEC count of the 3D NAND. Each table further specifies a number of errors that will result in garbage collection being performed.

Discussed herein are systems and methods for charging an access line to a non-volatile memory cell during a standby state, such as to prevent or mitigate standby-state charge loss. An embodiment of a memory device comprises a memory cell, a string driver circuit, and a charging circuit. The string driver circuit is coupled to the memory cell via a local word line, and has a common p-well. The charging circuit, in response to a voltage of a global word line of the memory device falling below a reference voltage during a standby state, couple a supply voltage to the common p-well of the string driver circuit to charge the global word line to a positive bias potential. The memory device includes a leakage compensation circuit to compensate for the junction leakage.

Discussed herein are systems and methods for charging an access line to a non-volatile memory cell during a standby state, such as to prevent or mitigate standby-state charge loss. An embodiment of a memory device comprises a memory cell, a string driver circuit, and a charging circuit. The string driver circuit is coupled to the memory cell via a local word line, and has a common p-well. The charging circuit, in response to a voltage of a global word line of the memory device falling below a reference voltage during a standby state, couple a supply voltage to the common p-well of the string driver circuit to charge the global word line to a positive bias potential. The memory device includes a leakage compensation circuit to compensate for the junction leakage.

The present technology relates to an electronic device. A memory device having improved memory block management performance according to the present technology includes a memory block, a peripheral circuit, and a control logic. The peripheral circuit performs a read operation and a program operation on a selected physical page among a plurality of physical pages. The control logic controls the peripheral circuit to read first logical page data stored in a first physical page and second logical page data stored in a second physical page among the plurality of physical pages, and additionally program the second logical page data into the first physical page using the read first and second logical page data.

The present technology relates to an electronic device. A memory device having improved memory block management performance according to the present technology includes a memory block, a peripheral circuit, and a control logic. The peripheral circuit performs a read operation and a program operation on a selected physical page among a plurality of physical pages. The control logic controls the peripheral circuit to read first logical page data stored in a first physical page and second logical page data stored in a second physical page among the plurality of physical pages, and additionally program the second logical page data into the first physical page using the read first and second logical page data.

According to one embodiment, a storage device includes a nonvolatile memory and a controller. The controller is configured to read data from the nonvolatile memory by applying a read voltage to the nonvolatile memory. The controller is configured to correct the read voltage based on a difference between a measured value of a bit number obtained when the data is read from the nonvolatile memory by applying the read voltage to the nonvolatile memory and an expected value of the bit number.