| 摘要 |
PURPOSE: A flash memory device and an erasing method therefor are provided to prevent an over-erasure for flash memory cells. CONSTITUTION: A flash memory device includes a cell array(1100), selection circuits(1200,1300), X-counter(1400), Y-counter(1500), a sense amplifying circuit(1600), a high voltage generator(2200) and an erasing control circuit(2100). The erasing control circuit(2100) includes a loop counter(1700), a bulk step counter(1800), a flag counter(1900) and a control logic part(2000). The erasing control circuit(2100) detects whether erasing voltages to memory cells are over pre-detection voltage or not. Also, the erasing control circuit(2100) controls the high voltage generator(2200) so that the erasing voltages to memory cells are not over pre-detection voltage. Thereby, an over-erasure can be prevented.
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