Patent ID: 8214583
Filing Date: 2012-07-03
Classification: G06F,G11C

Abstract:
1. A method of operating a re-programmable non-volatile memory system with a host system that generates a plurality of data files having unique individual file identifiers and offsets, the memory system having blocks of memory cells that are erased prior to new data being written therein, comprising: maintaining a pool of erased blocks available for storage of data of the files, the blocks in the pool having been erased prior to being needed for the storage of data of the files, receiving from the host data of the files and their unique individual file identifiers and offsets, storing the received data files individually in one or more of the erase pool blocks of the memory system, recording in a directory the identity of the blocks and locations therein in which data of the uniquely identified files are stored by their offset addresses without the use of any intermediate logical address conversion, thereafter receiving from the host a command to delete from the memory system one of the stored data files by its unique file identifier, thereafter identifying each of one or more blocks of memory cells containing data of the file being deleted, thereafter rendering obsolete all the data of the file being deleted that are stored in the identified one or more blocks, wherein thereafter no valid data remain in the memory system for the unique identifier of the file being deleted, and thereafter reclaiming space occupied by the obsolete data of the file being deleted in a manner that increases a number of erased blocks in the pool, wherein executing the received command to delete said one of the stored data files causes the number of erased blocks in the pool to be increased and no data to remain in the memory system for the unique identifier of the deleted file.