Data read method for flash memory

摘要

The invention provides a data read method. In one embodiment, a flash memory comprises a plurality of pages, and predetermined information is written into each of the pages of the flash memory. First, a target address of the flash memory is read according to a source read voltage to obtain source data and a source error correction code. When error bits of the source data cannot be corrected according to the source error correction code, the predetermined information corresponding to the source data is read from the flash memory according to the source read voltage to obtain correction information. The source data and the source error correction code are then amended according to the difference between the predetermined information and the correction information to obtain an amended data and an amended error correction code. Error bits of the amended data are then corrected according to the amended error correction code.

主权项

1. A data read method for a flash memory, wherein the flash memory comprises a plurality of pages, and predetermined information is written into each of the pages of the flash memory, and the predetermined information is a binary code with a predetermined value, and the binary code is constituted by a plurality of bits, comprising:
reading a target address of the flash memory according to a source read voltage to obtain source data and a source error correction code; correcting error bits of the source data according to the source error correction code in a first error correction process; when the error bits of the source data cannot be corrected in the first error correction process, reading the predetermined information corresponding to the source data from the flash memory according to the source read voltage; amending the source data according to the difference between the predetermined value of the predetermined information and the predetermined information read from the flash memory when the error bits of the source data cannot be corrected to obtain an amended data; amending the source error correction code according to the difference between the predetermined value of the predetermined information and the predetermined information read from the flash memory when the error bits of the source data cannot be corrected to obtain an amended error correction code; correcting error bits of the amended data according to the amended error correction code in a second error correction process; and when the error bits of the amended data are successfully corrected to obtain second output data in the second error correction process, sending the second output data to a host.