Method, device and computer program product for decoding a codeword

摘要

A method for decoding a codeword received from a flash memory is proposed. The flash memory comprises several multi-level flash memory cells, wherein each such multi-level flash memory cell stores one symbol of the codeword. An ECC decoder is arranged for decoding the codeword into a decoded codeword and is designed to correct a maximum number of errors. The method comprises an error check step for determining the number of errors in the codeword. If the number of errors is more than the maximum number of errors the ECC decoder can correct then at least one of a first symbol modification step and a second symbol modification step is performed. In the first symbol modification step a first modified codeword is generated by increasing the value of the symbol to the next higher value level and in the second symbol modification step a second modified codeword is generated by decreasing the value of the symbol (Si) to the next lower value level. In an analysis step the corrective effect of the symbol modification steps is calculated and in a return step the decoded codeword is determined based on the corrective effect, or an erasure of the codeword.