To store, in a memory block whose word lines are written successively in a word line writing order, a plurality of data pages that are ordered by logical page address, the pages are written to the word lines so that every page that is written to any one of the word lines has a higher logical page address than any page that is written to a subsequently written word line, regardless of the sequence in which the pages are received for writing. Alternatively, the pages are written to the word lines so that for every pair of written word lines, the word line of the pair that is earlier in the writing order has written thereto a page having a higher logical page address than at least one page written to the other word line of the pair.