Affordable Access

Refresh Frequency Reduction of Data Stored in SSDs Based on A-timer and Timestamps

  • Seif, Marcelino
  • Farjallah, Emna
  • Badets, Franck
  • Layer, Christophe
  • Chabchoub, Emna
  • Armani, Jean-Marc
  • Joffre, Francis
  • Anghel, Costin
  • Dilillo, Luigi
  • Gherman, Valentin
Publication Date
May 22, 2017
External links


Increasing the number of bits per cell and technology scaling are ways to reduce the cost per gigabyte of Flash memo- ries and solid-state drives (SSDs). Unfortunately, this trend has a negative impact on data retention time and cycling endurance. Periodic data refresh allows dealing with a reduced retention time and, implicitly, improves cycling endurance. A fixed data- refresh frequency is not optimal in the presence of a variable operating temperature since it may become unnecessarily large and alter the SSD response latency and energy consumption. Here, a flexible data-refresh methodology is proposed based on timestamps and approximations of the Arrhenius-curves em- ployed to describe the temperature impact on Flash data reten- tion. The proposed approximations can be easily implemented with the help of a processor-based solution or a proposed small module called A-timer. For an asymmetric temperature distri- bution between 30°C and 70°C, it is estimated that the refresh frequency can be reduced by more than 50× and almost 3× for failure mechanisms with activation energies of 1.1eV and 0.3eV, respectively.

Report this publication


Seen <100 times