Patent ID: 6760255
Filing Date: 2004-07-06
Classification: G06F,G11C

Abstract:
A method of operating a re-programmable non-volatile memory system having its memory cells organized into distinct blocks of a minimum number of cells that are simultaneously erased prior to re-programming, comprising:storing user data in a plurality of said blocks of a first group thereof, storing, in a second group of one or more of said blocks, records of characteristics of individual ones of the first group of blocks, the second group of blocks individually storing a plurality of said records for a plurality of the first group of blocks and a redundancy code calculated from said plurality of records, reading a plurality of records from at least one of the plurality of blocks of the second group and storing them in an additional memory, when accessing a given block of the first group, determining whether a given one of the records containing characteristics of the given block exists in the additional memory, and, if so, thereafter reading the given record from the additional memory, if the given record is determined not to be in the additional memory, reading a plurality of records from at least one of the second group of blocks including the given record and the redundancy code stored therewith, checking the validity of the read records by use of the read redundancy code, storing the plurality of records in the additional memory, and thereafter reading the given record from the additional memory, and utilizing the characteristics read from the given record in connection with accessing the given block.