Patent ID: 8499227

Claim:
A method for use with a nonvolatile solid state memory that is made up of a plurality of memory cells for storing user data where the memory cells are configured for storing said user data based on a physical property that can be set responsive to a programming operation and for reading the stored data, that is representative of the user data, in a read operation, said method comprising: reading a set of said stored data in said read operation such that an associated set of retrieved data is obtained by said read operation which retrieved data is influenced by one or more distortion mechanisms as a result of the set of stored data having been stored in and read from the nonvolatile solid state memory; generating a quality metric responsive to the retrieved data which quality metric changes in value responsive to differences between the user data and the associated retrieved data; establishing a relationship between a current value of the quality metric and a threshold value; and monitoring said relationship as being indicative of a degradation of the quality of said retrieved data, and selectively initiating an error response event responsive to said monitoring that changes the retrieved data based on the quality metric.