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US 7,849,382 B2Granted
Memory control circuit, nonvolatile storage apparatus, and memory control method
AssigneePanasonic Corporation
InventorsTetsushi Kasahara, Tomoaki Izumi, Masahiro Nakanishi, Kazuaki Tamura, Kiminori Matsuno, Yoshihisa Inagaki, Manabu Inoue
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Abstract
An address at which a writing error occurs is held, and after a completion of a series of writings, the data of the held address is read. Then, a faulty-block processing is performed only for the addresses, for which it is determined that retry of writing is required, thereby preventing an increase of faulty-blocks. This can suppress the problem that when a writing is performed in a particular flash memory, a writing error frequently occurs and a large number of faulty blocks occur.
Claims15
A memory control circuit for a rewritable nonvolatile memory comprising:
- a first management table that stores management data, which indicates a data writing condition of the nonvolatile memory at every data writing by blocks;
- a second management table that stores management data, which is a copy of the management data of said first management table upon completion of data writing of a predetermined unit of data, wherein the predetermined unit includes a plurality of blocks;
- a writer that writes the predetermined unit of data in the blocks of the nonvolatile memory based on the management data of said first management table;
- a management table updater that updates the management data of said first management table so that rewriting to the written blocks is forbidden;
- a determiner that determines whether or not the data writing to each block is normally executed;
- an error address register that registers an address of a block for which said determiner determines that the data writing is not normally executed;
- an error corrector that reads the data in the block identified by the address registered in said error address register, after completion of the writing of the predetermined unit of data, and that detects and corrects an error in the read data;
- and
- a termination controller that normally terminates, after copying the management data of said first management table to said second management table when the writing of the predetermined unit of data is set to be valid, based on a state of the error detected by said error corrector, and that abnormally terminates, after copying the management data of said second management table to said first management table when the writing of the predetermined unit of data is set to be invalid, based on the state of the error detected by said error corrector, so that the management data of the first management table is reverted to a state before the data writing of the predetermined unit of data is performed.
6 more elements
A nonvolatile storage apparatus comprising:
- a rewritable nonvolatile memory;
- a first management table that stores management data, which indicates a data writing condition of said nonvolatile memory at every data writing by blocks;
- a second management table that stores management data, which is a copy of the management data of said first management table upon completion of data writing of a predetermined unit of data, wherein the predetermined unit includes a plurality of blocks;
- a writer that writes the predetermined unit of data in the blocks of said nonvolatile memory based on the management data of said first management table;
- a management table updater that updates the management data of said first management table so that rewriting to the written blocks is forbidden;
- a determiner that determines whether or not the data writing to each block is normally executed;
- an error address register that registers an address of a block for which said determiner determines that the data writing is not normally executed;
- an error corrector that reads the data in the block identified by the address registered in said error address register, after completion of the writing of the predetermined unit of data, and that detects and corrects an error in the read data;
- and
- a termination controller that normally terminates, after copying the management data of said first management table to said second management table, when the writing of the predetermined unit of data is set to be valid, based on a state of the error detected by said error corrector, and that abnormally terminates, after copying the management data of said second management table to said first management table, when the writing of the predetermined unit of data is set to be invalid, based on the state of the error detected by said error corrector, so that the management data of the first management table is reverted to a state before the data writing of the predetermined unit of data is performed.
7 more elements
A memory control method for rewritable nonvolatile memory comprising:
- storing management data, indicating a data writing condition of the nonvolatile memory at every data writing by blocks in a first management table;
- storing management data, which is a copy of the management data of the first management table upon completion of data writing of a predetermined unit of data, to a second management table, the predetermined unit of data including a plurality of blocks;
- writing the predetermined unit of data in the blocks of the nonvolatile memory based on the management data of the first management table;
- updating the management data of the first management table so that rewriting to the written blocks is forbidden;
- determining whether or not the data writing to each block is normally executed;
- registering an address of a block for which it is determined that the data writing is not normally executed, to an error address register;
- reading data in the block identified by the address registered in the error address register, after completion of the writing of the predetermined unit of data,
- detecting and correcting an error in the read data;
- normally terminating, after copying the management data of the first management table to the second management table when the writing of the predetermined unit of data is set to be valid, based on a state of the detected error;
- and
- abnormally terminating, after copying the management data of the second management table to the first management table when the writing of the predetermined unit of data is set to be invalid, based on the state of the detected error, so that the management data of the first management table is reverted to a state before the data writing of the predetermined unit of data is performed.
8 more elements
Dependencies are inferred from the claim text.