A method for operating a memory cell of a multi-level NROM is described. The memory cell of the multi-level NROM comprises a nitride layer, wherein the nitride layer comprises a plurality of charge-trapping regions to store locally a plurality of charges as the first bit memory and the second bit of...http://www.google.de/patents/US6643170?utm_source=gb-gplus-sharePatent US6643170 - Method for operating a multi-level memory cell
