DRAM error detection, evaluation, and correction
AssigneeInternational Business Machines Corporation
InventorsMichele M. Franceschini, Hillery C. Hunter, Ashish Jagmohan, Charles A. Kilmer, Kyu-hyoun Kim, Luis A. Lastras-Montano, Moinuddin K. Qureshi
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Abstract
This disclosure includes a method for correcting errors on a DRAM having an ECC which includes writing data to a DRAM row, reading data from the DRAM row, detecting errors in the data that cannot be corrected by the DRAM's ECC, determining erasure information for the row, evaluating the errors using the erasure information, and correcting the errors in the data.
Claims20
A method for correcting errors in a dynamic random access memory (DRAM) system having associated logic that uses an error correcting code operable to detect and correct a single bit error, and to detect two or more bit errors, comprising:
- reading data from a row of the DRAM;
- detecting two or more errors in the data;
- and
- in response to the determining of two or more errors in the data:
- determining whether the row contains one or more weak cells and determining locations of any weak cells in the row, and
- determining whether the weak cells contain errors that can be corrected, and in response to determining that the weak cells contain errors that can be corrected, correcting the errors in the weak cells.
A method for correcting errors in a dynamic random access memory (DRAM) system having associated logic that uses an error correcting code operable to detect and correct a first number of bit errors, and to detect a second number of bit errors, the second number being greater than the first number, comprising:
- reading data from a row of the DRAM;
- detecting a particular number of bit errors in the data, the particular number being greater than the first number;
- and
- in response to the determining of two or more errors in the data:
- determining whether the row contains one or more weak cells and determining locations of any weak cells in the row, and
- determining whether the weak cells contain errors that can be corrected, and in response to determining that the weak cells contain errors that can be corrected, correcting the errors in the weak cells.
Dependencies are inferred from the claim text.