MULTIBIT PROGRAMMING METHOD IN A NON-VOLATILE MEMORY ALLOWING A NUMBER OF DATA STATE-FAILS AND DATA RECOVERY METHOD IN CASE OF PROGRAMMING FAIL

摘要

An error detection and data recovery operation for a non-volatile memory system. Even after a programming operation for a set of storage elements is successfully completed, the data of some storage elements may be corrupted. For example, erased state storage element may be disturbed by programming of other storage elements. To allow recovery of data in such situations, associated data latches can be configured to allow the erased state storage elements to be distinguished from other data states once programming is completed. Furthermore, a single read operation can be performed after programming is completed. Logical operations are performed using results from the read operation, and values in the data latches, to identify erased state storage elements which have strayed to another data state. If the number of errors exceeds a threshold, a full recovery operation is initiated in which read operations are performed for the remaining states.