Date Added: Sep 2009
NAND flash memories are the most widely used non-volatile memories due to their high data density and efficiency. In a NAND flash memory, cells are organized as blocks. A block has about 105 cells, and a cell can store one or more bits. Every block is partitioned into pages, where a page is the unit of a read or write operation. A prominent property of flash memories is block erasure. It means to change any stored data, the whole block must be erased first before rewriting. Block erasures significantly decrease the longevity and the speed of flash memories, so it is very important to reduce them.