Patent ID: 8238157
Filing Date: 2012-08-07
Classification: G11C

Abstract:
1. A method for data storage, comprising: in a memory that includes multiple analog memory cells, defining an erased state, a set of non-erased programming states and a partial subset of the non-erased programming states; initially storing data in a first group of the analog memory cells by programming each of at least some of the memory cells in the first group from the erased state to a respective non-erased programming state selected from the set of non-erased programming states; after initially storing the data, programming a second group of the analog memory cells, which potentially cause interference to the first group; and after programming the second group, selectively re-programming the first group with the data by repeating programming of only the memory cells in the first group whose respective programming states belong to the partial subset, wherein initially storing the data comprises writing respective storage values into the memory cells in the first group and verifying the written storage values using first verification thresholds, and wherein selectively re-programming the first group comprises re-writing the storage values that are associated with the partial subset, and verifying the re-written storage values using second verification thresholds, higher than the corresponding first verification thresholds.