Semiconductor nonvolatile storage device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKenji Misumi, Atsushi Fujiwara, Masanori Matsuura, Toshio Nishimoto
Life of this patent
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Abstract
A writing operation selecting circuit is provided for selecting a temporary writing operation having a prescribed writing time for a memory cell transistor element and an additional writing operation for the memory cell transistor element. A writing time control circuit is provided for controlling an additional writing operation time by an output signal of the writing operation selecting circuit.
Claims35
A nonvolatile semiconductor storage device comprising:
- a writing means having a first writing function for writing same write data in a memory cell in a first writing level and a second writing function for writing in a second writing level which is different from the first writing level;
- and
- a writing level selecting means for selecting any one of the first writing level and the second writing level for every writing area.
A writing method of a nonvolatile semiconductor storage device comprising:
- selecting of any one of a first writing operation for writing same write data for every writing area in a memory cell in a first writing level and a second writing operation for writing in a second writing level which is different from the first writing level;
- and
- performing the selected writing operation.
A host device data storage system comprising:
- a nonvolatile semiconductor storage device which has a first writing function for writing same writing date in a memory cell in a first writing level and a second writing function for writing in a second writing level which is different from the first writing level, and comprises a writing level selecting means for selecting any one of the first writing level and the second writing level for every writing area;
- and
- a mode of additionally writing the data written in a first writing level into a second writing level.
A nonvolatile semiconductor storage device comprising:
- a writing operation selecting circuit for selecting, for the same data in a memory cell, a first writing operation for writing in a first writing level and a second writing function for writing in a second writing level which is different from the first writing level;
- and
- an address decoder circuit for outputting the writing signal of the writing operation selecting circuit to the memory cell by selecting for the writing area.
Dependencies are inferred from the claim text.