Systems and methods for read level tracking and optimization are described. Pages from a wordline of a flash memory device read and the raw page data read from the wordline may be buffered in a first set of buffers. The raw page data for each of the pages may be provided to a decoder for decoding and the decoded page data for each of the pages buffered in a second set of buffers. First bin identifiers may be identified for memory cells of the wordline based on the raw page data and second bin identifiers may be identified for the memory cells of the wordline based on the decoded page data. Cell-level statistics may be accumulated based on the first bin identifiers and the second bin identifiers, and a gradient may be determined for respective read levels based on decoding results for each of the pages and the cell-level statistics. Settings for the read levels may be configured in the flash memory device based on the determined gradients.

A memory system includes a plurality of memory cells, and the memory cells are multiple-level cells. The memory system performs program operations to program the memory cells. After each program operation, at least one threshold voltage test is performed to determine if threshold voltages of the memory cells are greater than the verification voltage. When the threshold voltage of a first memory cell is determined to be greater than a first verification voltage, the first memory cell will be inhibited from being programmed during the next program operation. When the threshold voltage of a second memory cell is determined to newly become greater than a second verification voltage, where the second verification voltage is greater than the first verification voltage, the second memory cell will be programmed again during the next program operation.

A memory device that includes a plurality of memory cells arranged in rows and columns, a plurality of bit lines each connected to one of the columns of memory cells, and a plurality of differential sense amplifiers each having first and second inputs and an output. For each of the differential sense amplifiers, the differential sense amplifier is configured to generate an output signal on the output having an amplitude that is based upon a difference in signal amplitudes on the first and second inputs, the first input is connected to one of the bit lines, and the second input is connected to another one of the bit lines. Alternately, one or more sense amplifiers are configured to detect signal amplitudes on the bit lines, and the device includes calculation circuitry configured to produce output signals each based upon a difference in signal amplitudes on two of the bit lines.

Systems and methods for read level tracking and optimization are described. Pages from a wordline of a flash memory device read and the raw page data read from the wordline may be buffered in a first set of buffers. The raw page data for each of the pages may be provided to a decoder for decoding and the decoded page data for each of the pages buffered in a second set of buffers. First bin identifiers may be identified for memory cells of the wordline based on the raw page data and second bin identifiers may be identified for the memory cells of the wordline based on the decoded page data. Cell-level statistics may be accumulated based on the first bin identifiers and the second bin identifiers, and a gradient may be determined for respective read levels based on decoding results for each of the pages and the cell-level statistics. Settings for the read levels may be configured in the flash memory device based on the determined gradients.

Numerous embodiments are provided for compensating for drift error in non-volatile memory cells within a VMM array in an analog neuromorphic memory system. For example, in one embodiment, a circuit is provided for compensating for drift error during a read operation, the circuit comprising a data drift monitoring circuit coupled to the array for generating an output indicative of data drift; and a bitline compensation circuit for generating a compensation current in response to the output from the data drift monitoring circuit and injecting the compensation current into one or more bitlines of the array.

Methods of operating a memory device include programming a page of a memory block of the memory device using a particular starting programming voltage, determining a programming voltage indicative of a programming efficiency of the page of the memory block during programming of the page of the memory block, storing a representation of the programming voltage indicative of the programming efficiency of the page of the memory block, setting a starting programming voltage for a different page of the memory block in response to the stored representation of the programming voltage indicative of the programming efficiency of the page of the memory block, and programming the different page of the memory block using its starting programming voltage.

Methods of operating a memory device include programming a page of a memory block of the memory device using a particular starting programming voltage, determining a programming voltage indicative of a programming efficiency of the page of the memory block during programming of the page of the memory block, storing a representation of the programming voltage indicative of the programming efficiency of the page of the memory block, setting a starting programming voltage for a different page of the memory block in response to the stored representation of the programming voltage indicative of the programming efficiency of the page of the memory block, and programming the different page of the memory block using its starting programming voltage.

Technology is disclosed herein for simultaneous lower tail program verify with upper tail verify. The memory system may apply a reference voltage to a word line following applying a program voltage to the word line. The memory system senses the first set of memory cells targeted for a first data state and the second set of memory cells targeted for a second data state. The memory system determines whether memory cells in the first set have a Vt greater than a maximum target Vt for the first data state based on the sensing of the first set of memory cells. The memory system also determines whether memory cells in the second set have a Vt less than a minimum target Vt for the second data state based on the sensing of the second set of memory cells.

A system and method of programming user data into a memory cell includes receiving a first user data to be programmed in a memory controller, selecting a memory cell for programming the first user data and measuring at least one health characteristic of the selected memory cell. At least one programming parameter of the selected memory cell is adjusted and the first user data is programmed to the selected memory cell using the adjusted programming parameter corresponding to the selected memory cell.

Techniques are provided for avoiding over-programming which can occur on memory cells connected to a data word line at a source-side of a block of word lines. A gradient in the channel potential is created during a program voltage between the data word line and an adjacent dummy word line. This gradient generates electron-hole pairs which can contribute to over programming, where the over programming is worse at higher temperatures. In one aspect, pass voltages of unselected word lines are set to be relatively lower when the temperature is relatively higher, and when the selected word line is among a set of one or more source-side word lines. On the other hand, the pass voltages are set to be relatively higher when the temperature is relatively higher, and when the selected word line is not among the one or more source-side word lines.