Life warning generation system and method of semiconductor storage device equipped with flash memory
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsShinichi Mizoguchi, Masatoshi Kimura, Takayuki Shinohara
Life of this patent
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Abstract
A semiconductor storage device is equipped with flash memories each flash memory has a limited size of spare storage area for rewriting data when a write error occurs, and the storage device calculates the remaining size of the spare storage area after the completion of the re-writing, and examines whether or not the remaining size is smaller than a predetermined value, and generates a warning when the remaining size is smaller than the predetermined value, to thereby acknowledge that the life of each flash memory comes close to the end before completely used up.
Claims13
A semiconductor storage device equipped with flash memories each having a limited size of a spare storage area, said semiconductor storage device comprising:
- an error decision unit for judging whether or not an error occurs during writing of data;
- a replacing unit for rewriting data to the spare storage area when said error decision unit judges that an error occurs;
- a spare area size calculating unit for calculating a remaining size of the spare storage area after the data has been re-written to the spare storage area;
- a spare area checking unit for comparing the remaining size of the spare storage area with a predetermined value;
- and
- a warning generator for generating a warning when the remaining size of the spare storage area is smaller than the predetermined value.
A warning generating system of a semiconductor storage device exchanging commands and data with an external system, the semiconductor storage device being equipped with flash memories each having a limited size of a spare storage area, said system comprising:
- an error decision unit for judging whether or not an error occurs during writing of data;
- a replacing unit for rewriting data to the spare storage area when said error decision unit judges that an error occurs;
- a spare area size calculating unit for calculating a remaining size of the spare storage area after the data has been re-written to the spare storage area;
- a spare area checking unit for comparing the remaining size of the spare storage area with a predetermined value;
- and
- a warning generator for generating a warning when the remaining size of the spare storage area is smaller than the predetermined value.
A warning generating method of a semiconductor storage device equipped with flash memories each having a limited size of a spare storage area, the method comprising:
- judging whether or not an error occurs during writing of data;
- rewriting data to the spare storage area when it is judged that an error occurs;
- calculating a remaining size of the spare storage area after the data has been re-written to the spare storage area;
- comparing the remaining size of the spare storage area with a predetermined value;
- and
- generating a warning when the remaining size of the spare storage area is smaller than the predetermined value.
A semiconductor storage device equipped with flash memories each having a limited number of rewriting operations to be subjected and each flash memory being provided with a spare storage area for replacing a defective portion caused in writing data, said semiconductor storage device comprising:
- an error decision unit for judging whether or not an error occurs in a defective portion during a data writing operation;
- a replacing unit for replacing the defective portion by the spare storage area to write the data when the error decision unit judges that an error occurs;
- a command receiving unit for receiving a remaining number examination command from an external equipment requesting an examination of a remaining size of the spare storage area;
- a remaining spare size calculating unit for calculating a remaining size in number of the spare storage area in response to the remaining number examination command after the data has been written to the spare storage area;
- and
- a spare area checking unit for comparing the calculated remaining size of the spare storage area with a predetermined value.
Dependencies are inferred from the claim text.