Patent ID: 8972675
Filing Date: 2015-03-03
Classification: G06F,G11C

Abstract:
1. A method of operating a three dimensional nonvolatile memory formed as a plurality of physical levels of memory cells disposed above a substrate comprising: writing data in a first format in a plurality of separately selectable sets of strings of a first block; writing the data in a second format in at least a second block; subsequently sampling the data written in the first format from the first block, sample data including: (i) data of all word lines of a sample set of strings and (ii) data of a sample word line of each of the sets of strings of the plurality; if the sample data meets a standard, then discarding the data written in the second format in the at least a second block; and if the sample data does not meet the standard, then discarding the data in the first format in the first block.