Nonvolatile semiconductor storage device
AssigneeKabushiki Kaisha Toshiba
InventorsMasanobu SHIRAKAWA, Toshio Yamamura
Life of this patent
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Abstract
A nonvolatile semiconductor storage device includes: a memory cell array in which electrically rewritable nonvolatile memory cells are arranged; and a register that holds good/bad information on a specific area that requires high reliability in a user accessible area of the memory cell array. An address conversion circuit internally accesses, when the specific area is bad and is accessed, a backup area in the user accessible area based on the good/bad information in the register. When the specific area is bad and the backup area is accessed, on the other hand, the address conversion circuit internally accesses the specific area based on the good/bad information in the register.
Claims20
A nonvolatile semiconductor storage device comprising:
- a memory cell array in which electrically rewritable nonvolatile memory cells are arranged;
- a register that holds good/bad information on a specific area that requires high reliability in a user accessible area of the memory cell array;
- and
- an address conversion circuit that internally accesses a backup area in the user accessible area based on the good/bad information in the register when the specific area is bad and is accessed, whereas internally accesses the specific area based on the good/bad information in the register, when the specific area is bad and the backup area is accessed.
A nonvolatile semiconductor storage device comprising:
- a memory cell array in which electrically rewritable nonvolatile memory cells are arranged;
- and
- an address conversion circuit that internally accesses a backup area in the user accessible area when a specific area that requires high reliability in a user accessible area of the memory cell array is bad and is accessed, whereas internally accesses the specific area when the specific area is bad and the backup area is accessed.
Dependencies are inferred from the claim text.