Detection and decoding in flash memories using correlation of neighboring bits and probability based reliability values

摘要

Methods and apparatus are provided for detection and decoding in flash memories using a correlation of neighboring bits or errors in neighboring bits. Data from a flash memory device is processed by obtaining one or more read values for a plurality of bits in one or more pages of the flash memory device; converting the one or more read values for the plurality of bits to a reliability value, such as a log likelihood ratio (LLR), for a given bit among said plurality of bits based on a probability that a data pattern was written to the plurality of bits given that a particular pattern was read from the plurality of bits; and decoding the given bit in a given page of the one or more pages using the reliability value. The probability may be obtained from one or more transition probability tables, or may be based on one or more reference cells, prior decoded decisions or performance factors.