A method of managing programming errors in a multilevel NAND flash memory is provided. The multilevel NAND flash memory uses a two-pass programming algorithme.g., a first programming pass and a second programming passfor programming a memory block being organized in pages, sharing a word line. The method comprises performing the first programming pass for at least one memory page, reading the at least one memory page between the first programming pass and the second programming pass, determining an error count value for the at least one programmed memory page, and responsive to determining that the error count value is below a threshold value, performing the second programming pass with active data.

Numerous embodiments of a precision programming algorithm and apparatus are disclosed for precisely and quickly depositing the correct amount of charge on the floating gate of a non-volatile memory cell within a vector-by-matrix multiplication (VMM) array in an artificial neural network. Selected cells thereby can be programmed with extreme precision to hold one of N different values.

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.

Memory devices might include a controller configured to cause the memory device to apply a first plurality of incrementally increasing programming pulses to control gates of a particular plurality of memory cells selected for programming to respective intended data states, determine a first occurrence of a criterion being met, store a representation of a voltage level corresponding to a particular programming pulse in response to the first occurrence of the criterion being met, set a starting programming voltage for a second plurality of incrementally increasing programming pulses in response to the stored representation of the voltage level corresponding to the particular programming pulse, and apply the second plurality of incrementally increasing programming pulses to control gates of a different plurality of memory cells selected for programming to respective intended data states.

A nonvolatile semiconductor memory device includes a control circuit configured to control a soft program operation of setting nonvolatile memory cells to a first threshold voltage distribution state of the nonvolatile memory cells. When a characteristic of the nonvolatile memory cells is in a first state, the control circuit executes the soft program operation by applying a first voltage for setting the nonvolatile memory cells to the first threshold voltage distribution state to first word lines, and applying a second voltage higher than the first voltage to a second word line. When the characteristic of the nonvolatile memory cells is in a second state, the control circuit executes the soft program operation by applying a third voltage equal to or lower than the first voltage to the first word lines and applying a fourth voltage lower than the second voltage to the second word line.

A memory system includes a nonvolatile memory device including a plurality of memory cells; and a controller including a control unit and a random-access memory, and configured to determine, by applying a program verify voltage to at least one memory cell to be programmed with program data, whether the program data is programmed, wherein the control unit determines percentages of a count of read requests received from a host device and a count of program requests received from the host device, and adjusts a level of the program verify voltage based on the percentages.

A memory device may include: a control circuit comprising a first verification component suitable for counting the number of memory cells in the selected word line having an excessively high threshold voltage as excessive memory cells, after a program operation is completed; and a second verification component suitable for counting the number of failed bits when the number of excessive memory cells counted is greater than or equal to an excess threshold value, and suitable for outputting a pass or fail signal for the program operation according to the count of at least one of the first verification component and the second verification component.

A non-volatile storage system includes a mechanism to compensate for over programming during the programming process. That is, after the programming process starts for a set of data and target memory cells, and prior to the programming process completing for the set of data and the target memory cells, the system determines whether a first group of the memory cells has more than a threshold number of over programmed memory cells. If so, then the system adjusts programming of a second group of memory cells to reduce the number of programming errors.

A non-volatile storage system includes a mechanism to compensate for over programming during the programming process. That is, after the programming process starts for a set of data and target memory cells, and prior to the programming process completing for the set of data and the target memory cells, the system determines whether a first group of the memory cells has more than a threshold number of over programmed memory cells. If so, then the system adjusts programming of a second group of memory cells to reduce the number of programming errors.

A non-volatile storage system includes a mechanism to compensate for over programming during the programming process. That is, after the programming process starts for a set of data and target memory cells, and prior to the programming process completing for the set of data and the target memory cells, the system determines whether a first group of the memory cells has more than a threshold number of over programmed memory cells. If so, then the system adjusts programming of a second group of memory cells to reduce the number of programming errors.