SOFT DECODING OF HARD AND SOFT BITS READ FROM A FLASH MEMORY

摘要

to read the one or more flash memory cells, the threshold voltage is at least one integral reference voltage of each cell and at least one of a small number compared to the reference voltage. Based on this comparison, the estimated probability of each measurement value of each bit of the original bit pattern of each cell is calculated. This provides a plurality of the estimated probability measure. Based at least in part on at least two of the estimated probability of measurements, each of the original bit pattern of the cell is estimated. Preferably, the estimated probability measure is a bit pattern (s) are (collectively), for example, the first probability measure that is converted to a final probability measured under a limited set of candidate set of code words, such as. ; flash memory cells, the threshold voltage, a constant reference voltage, the reference voltage a small number, bit patterns, the probability measure, the original bit pattern, code words, the maximum post-probability estimation, maximum likelihood decoding