Method, memory controller, and memory system for reading data stored in flash memory

摘要

An exemplary method for reading data stored in a flash memory includes: selecting an initial gate voltage combination from a plurality of predetermined gate voltage combination options; controlling a plurality of memory units in the flash memory according to the initial gate voltage combination, and reading a plurality of bit sequences; performing a codeword error correction upon the plurality of bit sequences, and determining if the codeword error correction successful; if the codeword error correction is not successful, determining an electric charge distribution parameter; determining a target gate voltage combination corresponding to the electric charge distribution parameter by using a look-up table; and controlling the plurality of memory units to read a plurality of updated bit sequences according to the target gate voltage combination.

主权项

1. A method for reading data stored in a flash memory, comprising:
selecting an initial gate voltage combination from a plurality of predetermined gate voltage combination options; controlling a plurality of memory units in the flash memory according to the initial gate voltage combination, and reading a plurality of bit sequences; performing a codeword error correction operation upon the plurality of bit sequences, and determining whether the codeword error correction operation performed upon the plurality of bit sequences is successful; when the codeword error correction operation performed upon the plurality of bit sequences is not successful, determining an electric charge distribution parameter corresponding to the initial gate voltage combination; determining a target gate voltage combination corresponding to the electric charge distribution parameter according a look-up table (LUT), wherein the target gate voltage combination comprises a plurality of threshold voltage levels; and controlling the plurality of memory units according to the target gate voltage combination, to read a plurality of updated bit sequences.