Wear leveling in EEPROM emulator formed of flash memory cells

    公开(公告)号:US11257555B2

    公开(公告)日:2022-02-22

    申请号:US17006550

    申请日:2020-08-28

    Abstract: The present invention relates to systems and methods for implementing wear leveling in a flash memory device that emulates an EEPROM. The embodiments utilize an index array, which stores an index word for each logical address in the emulated EEPROM. Each bit in each index word is associated with a physical address for a physical word in the emulated EEPROM, and the index word keeps track of which physical word is the current word for a particular logical address. The use of the index word enables a wear leveling algorithm that allows for a programming command to a logical address to result in: (i) skipping the programming operation if the data stored in the current word does not contain a “1” that corresponds to a “0” in the data to be stored, (ii) reprogramming one or more bits of the current word in certain situations, or (iii) shifting to and programming the next physical word in certain situations.

    System and method for minimizing floating gate to floating gate coupling effects during programming in flash memory

    公开(公告)号:US10699787B2

    公开(公告)日:2020-06-30

    申请号:US16783286

    申请日:2020-02-06

    Abstract: An improved programming technique for non-volatile memory cell arrays, in which memory cells to be programmed with higher programming values are programmed first, and memory cells to be programmed with lower programming values are programmed second. The technique reduces or eliminates the number of previously programmed cells from being adversely incrementally programmed by an adjacent cell being programmed to higher program levels, and reduces the magnitude of adverse incremental programming for most of the memory cells, which is caused by floating gate to floating gate coupling. The memory device includes an array of non-volatile memory cells and a controller configured to identify programming values associated with incoming data, and perform a programming operation in which the incoming data is programmed into at least some of the non-volatile memory cells in a timing order of descending value of the programming values.

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