Spreading modulation for multi-level non-volatile memories Articles uri icon

publication date

  • March 2016

start page

  • 1110

end page

  • 1119

issue

  • 3

volume

  • 64

International Standard Serial Number (ISSN)

  • 0090-6778

Electronic International Standard Serial Number (EISSN)

  • 1558-0857

abstract

  • The aggressive scaling of NAND flash memories has
    caused significant degradation in their reliability and endurance.
    One of the dominant factors in this degradation is the intercell-interference, by which the programming of a cell can affect
    nearby neighboring cells corrupting the information that they
    store. This paper proposes a new data representation scheme,
    which increases endurance and significantly reduces the probability of error caused by inter-cell-interference. The method is
    based on using an orthogonal code to spread each bit across
    multiple cells, resulting in lower variance for the voltages being
    programmed in the cells. This new data representation method
    is also shown to present many of the advantages that spreading
    sequences bring to wireless communications. For example, multiple information sequences can be written on the same cells at
    different times without interfering with each other. It also allows
    storing additional information on an already programmed memory in such a way that the new information is hidden by the
    noise.

subjects

  • Mechanical Engineering

keywords

  • memory signal processing; nand flash memory; modulation; spreading sequence; cdma