A method of fast erasing a low-current EEPROM array. The EEPROM array comprises bit line groups, word lines, common source lines, and sub-memory arrays. Each sub-memory array includes a first memory cell and a second memory cell. The first memory cell is connected with one bit line of a first bit line group, a first common source line, and a first word line. The second memory cell is connected with the other bit line of the first bit line group, the first common source line, and a second word line. The first and second memory cells are operation memory cells and symmetrically arranged at two sides of the first common source line. The source or the drain is floated during erasing to perform the fast bytes-erasing with low current, low voltage and low cost.

A method of programming data into a memory device including an array of memory cells is disclosed. The method comprises receiving at least one program command that addresses a number of the memory cells for a programming operation to program data in the memory cells. The at least one program command is executed by iteratively carrying out at least one program/verify cycle to incrementally program the addressed memory cells with the program data. A secondary command may be selectively received after initiating but before completing the programming operation. The programming operation may be selectively resumed by first verifying the memory cells, then carrying out at least one program/verify cycle.

According to one embodiment, a memory device comprises a first memory cell configured to store data, a first word line connected to the first memory cell, a first circuit configured to supply a voltage to the first word line, a second circuit configured to control the first circuit, and a sequencer configured to control the first circuit and the second circuit. The sequencer, when data is written to the first memory cell, determines whether a condition is satisfied or not. The sequencer causes the second circuit to generate a first voltage, when the sequencer determines that the condition is not satisfied, and causes the second circuit to generate a second voltage which is higher than the first voltage, when the sequencer determines that the condition is satisfied.

A nonvolatile memory device includes a memory cell array including first to fourth planes, a page buffer circuit that includes first to fourth page buffer units connected with the first to fourth planes, respectively, an input/output circuit that includes a first input/output unit connected with the first to fourth page buffer units and a second input/output unit connected with the second and fourth page buffer units, and control logic that controls the input/output circuit to output first data from one of the first to fourth page buffer units through the first input/output unit in a first read mode and output second data from one of the first and third page buffer units through the first input/output unit and third data from one of the second and fourth page buffer units through the second input/output unit in a second read mode.

In a memory controller configured to control a memory device including a plurality of memory blocks, the memory controller comprising: a memory interface configured to exchange data with the memory device; and a pre-program controller configured to perform a read operation on a last page of a program sequence for a plurality of pages in an erase target memory block when the memory device is in an idle state, and perform a pre-program operation on the erase target memory block according to the result obtained by performing the read operation, wherein the erase target memory block is a memory block on which an erase operation is to be performed among the plurality of memory blocks, and wherein the erase operation on the erase target memory block is performed after the pre-program operation is performed.

Systems and methods for string-based erase verify to create partial good blocks are disclosed. A block in non-volatile flash memory may include multiple strings. In practice, one string may be slower to erase than other strings. In analyzing the strings, the memory device may iteratively analyze the strings to verify as erased. As one example, the iterations are modified by changing which strings are erased in the subsequent iterations (e.g., only the strings that fail the erase verify). As another example, a predetermined number of iterations are performed after a majority of the strings are verified as erased. In this way, the strings verified as erased need not undergo more deep erasing, which may damage the strings. Further, if fewer than all of the strings are verified as erased, the memory device may designate the block as a partially good block.

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 non-volatile memory has an array of non-volatile memory cells, first reference word lines and second reference word lines, and sense amplifiers. The sense amplifiers read system data, that has been written to supplemental non-volatile memory cells of the first reference word lines, using comparison of the supplemental non-volatile memory cells of the first reference word lines to supplemental non-volatile memory cells of the second reference word lines. Status of erasure of the non-volatile memory cells of the array is determined based on reading the system data.

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 nonvolatile memory device includes a memory cell array including first to fourth planes, a page buffer circuit that includes first to fourth page buffer units connected with the first to fourth planes, respectively, an input/output circuit that includes a first input/output unit connected with the first to fourth page buffer units and a second input/output unit connected with the second and fourth page buffer units, and control logic that controls the input/output circuit to output first data from one of the first to fourth page buffer units through the first input/output unit in a first read mode and output second data from one of the first and third page buffer units through the first input/output unit and third data from one of the second and fourth page buffer units through the second input/output unit in a second read mode.