Patent ID: 8327230

Claim:
A data reading method applied for a sector of a flash memory, said sector storing a data, an ECC checking information and a redundant code, and said method comprising the steps of: (a) performing an ECC decoding process on said data based on said redundant code; (b) determining whether or not said ECC decoding process is completed, and if said ECC decoding process is completed, outputting said processed data, and if said ECC decoding process is not completed, proceeding to step (c); (c) determining whether a number of instances of a stored byte sequence with a predetermined value in said sector exceeds a threshold value, and if said number does exceed said threshold value, marking said sector to be an erased sector, and if said number does not exceed said threshold value, proceeding to step (d); and (d) determining whether said sector has uncorrectable error or said sector is an erased sector based on said error checking code.