Nonvolatile semiconductor storage device capable of correctly reading selected memory cell and read method
AssigneeSharp Kabushiki Kaisha
InventorAtsushi Semi
Life of this patent
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AssigneeSharp Kabushiki Kaisha
InventorAtsushi Semi
Estimating the term…
A selected memory cell is correctly read even when a threshold value of a non-selected memory cell that shares a word line is low. When reading a memory cell MC12, a discharge transistor select circuit 47 selectively discharges a bit line BL2 connected to the memory cell MC12 and two bit lines BL0 and BL1 that are adjacent to the bit line BL2. A precharge control circuit 46 fixes to a precharge voltage a center bit line among five bit lines that include a bit line BL3 connected to the memory cell MC12 and four bit lines that are adjacent to the bit line BL3 and brings the remaining bit lines into a floating state with the precharge voltage. Thus, the potential of the bit line BL3 is prevented from being lowered as a consequence of a leak current occurring via the non-selected memory cell MC when the threshold value of the selected memory cell MC12 is high, by which the erroneous determination that the ON-state is provided is prevented from being made.
A nonvolatile semiconductor storage device having a plurality of nonvolatile memory cells arranged in a matrix form and bit lines and word lines connected to the nonvolatile memory cells, the nonvolatile memory cells adjoining in a direction in which the word lines extend sharing one bit line, the device comprising:
A method for reading a nonvolatile semiconductor storage device having a plurality of nonvolatile memory cells arranged in a matrix form and bit lines and word lines connected to the nonvolatile memory cells, the nonvolatile memory cells adjoining in a direction in which the word lines extend sharing one bit line, the method comprising the steps of:
Dependencies are inferred from the claim text.