NONVOLATILE MEMORY WITH ERROR CORRECTION BASED ON THE LIKEHOOD THE ERROR MAY OCCUR

摘要

In a nonvolatile memory system, data is read from a memory array and used to obtain likelihood values, which are then provided to a soft-input soft-output decoder. The soft-input soft-output. decoder calculates output likelihood values from input likelihood values and from parity data that was previously added according to an encoding scheme. The likelihood is derived by comparing a measured memory cell voltage with more than one reference voltages.