06751766 is referenced by 235 patents.

The quality of data stored in a memory system is assessed by different methods, and the memory system is operated according to the assessed quality. The data quality can be assessed during read operations. Subsequent use of an Error Correction Code can utilize the quality indications to detect and reconstruct the data with improved effectiveness. Alternatively, a statistics of data quality can be constructed and digital data values can be associated in a modified manner to prevent data corruption. In both cases the corrective actions can be implemented specifically on the poor quality data, according to suitably chosen schedules, and with improved effectiveness because of the knowledge provided by the quality indications. These methods can be especially useful in high-density memory systems constructed of multi-level storage memory cells.

Title
Increasing the effectiveness of error correction codes and operating multi-level memory systems by using information about the quality of the stored data
Application Number
10/152137
Publication Number
6751766 (B2)
Application Date
May 20, 2002
Publication Date
June 15, 2004
Inventor
Geoffrey S Gongwer
Los Altos
CA, US
Stephen Jeffrey Gross
Cupertino
CA, US
Daniel C Guterman
Fremont
CA, US
Agent
Parsons Hsue & de Runtz
US
Assignee
SanDisk Corporation
CA, US
IPC
G11C 29/00
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