Error checking and correcting decoding method and apparatus

An error checking and correcting (ECC) decoding method, comprising:

• temporarily storing, by a buffer circuit, at least one codeword outputted from a non-volatile memory;
• performing an ECC decoding operation on the at least one codeword using reference information by a decoding circuit, wherein when the decoding circuit fails to decode a first codeword of the at least one codeword by the ECC decoding operation, the decoding circuit performs the ECC decoding operation on a second codeword of the at least one codeword to produce decoded data;
• checking whether a change has occurred from each codeword bit of the second codeword to a corresponding bit of the decoded data by the decoding circuit;
• determining whether a bit position of the changed corresponding bit is present among all bit Positions of the first codeword by the decoding circuit, comprising:
• if the bit position is presented, in accordance with the bit position of the changed corresponding bit, correspondingly changing a bit value located in the bit position in the first codeword to change the first codeword to a modified codeword by the decoding circuit, or correspondingly changing a reference value located in the bit position in the reference information to change the reference information to modified information by the decoding circuit, and if the bit position is not presented, performing the ECC decoding operation on another codeword of the at least one codeword to produce decoded data by the decoding circuit;
• and
• performing the ECC decoding operation again on the modified codeword by the decoding circuit, or performing the ECC decoding operation again on the first codeword using the modified information by the decoding circuit, or performing the ECC decoding operation again on the modified codeword using the modified information by the decoding circuit.