| CPC G11C 16/16 (2013.01) [G11C 16/3431 (2013.01); G11C 16/3445 (2013.01)] | 20 Claims |
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1. A block erase method for flash memory, wherein the block erase method is to perform a block erase on a block of the flash memory, and the block has a predetermined block size, the block erase method comprising:
setting the block to have M partitioned blocks, wherein each block size of the M partitioned blocks is smaller than the predetermined block size;
setting M erase step threshold values within a maximum erase step to generate (M+1) erase step determining intervals;
performing an erase verification on bytes byte-by-byte in each of the M partitioned blocks when performing the block erase;
when the byte does not pass the erase verification, checking an erase step of the byte;
determining which a specific interval among the (M+1) erase step determining intervals the erase step is therein; and
performing the block erase on the partitioned blocks corresponding to the specific interval, returning to an erase verification stage to perform the erase verification after the block erase is completed,
wherein in a case that the erase step is less than or equal to a first erase step threshold value and in a first erase step determining interval, the block erase is performed by using the predetermined block size, and
in a case that the erase step is in a j-th (2≤j≤M+1) erase step determining interval, the block erase is performed by using a block size of a (j−1)-th partitioned block.
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