Memory states of a multi-bit memory cell are demarcated by generating read reference signals having levels that constitute boundaries of the memory states. The read reference signals may be dependent upon the levels of programming reference signals used for controlling the programming of the memory cell....http://www.google.es/patents/US6381172?utm_source=gb-gplus-sharePatente US6381172 - Memory apparatus including programmable non-volatile multi-bit memory cell, and apparatus and method for demarcating memory states of the cell
Memory apparatus including programmable non-volatile multi-bit memory cell ...
