1,195 research outputs found
EDACs and test integration strategies for NAND flash memories
Mission-critical applications usually presents several critical issues: the required level of dependability of the whole mission always implies to address different and contrasting dimensions and to evaluate the tradeoffs among them. A mass-memory device is always needed in all mission-critical applications: NAND flash-memories could be used for this goal. Error Detection And Correction (EDAC) techniques are needed to improve dependability of flash-memory devices. However also testing strategies need to be explored in order to provide highly dependable systems. Integrating these two main aspects results in providing a fault-tolerant mass-memory device, but no systematic approach has so far been proposed to consider them as a whole. As a consequence a novel strategy integrating a particular code-based design environment with newly selected testing strategies is presented in this pape
Increasing Flash Memory Lifetime by Dynamic Voltage Allocation for Constant Mutual Information
The read channel in Flash memory systems degrades over time because the
Fowler-Nordheim tunneling used to apply charge to the floating gate eventually
compromises the integrity of the cell because of tunnel oxide degradation.
While degradation is commonly measured in the number of program/erase cycles
experienced by a cell, the degradation is proportional to the number of
electrons forced into the floating gate and later released by the erasing
process. By managing the amount of charge written to the floating gate to
maintain a constant read-channel mutual information, Flash lifetime can be
extended. This paper proposes an overall system approach based on information
theory to extend the lifetime of a flash memory device. Using the instantaneous
storage capacity of a noisy flash memory channel, our approach allocates the
read voltage of flash cell dynamically as it wears out gradually over time. A
practical estimation of the instantaneous capacity is also proposed based on
soft information via multiple reads of the memory cells.Comment: 5 pages. 5 figure
Memristor MOS Content Addressable Memory (MCAM): Hybrid Architecture for Future High Performance Search Engines
Large-capacity Content Addressable Memory (CAM) is a key element in a wide
variety of applications. The inevitable complexities of scaling MOS transistors
introduce a major challenge in the realization of such systems. Convergence of
disparate technologies, which are compatible with CMOS processing, may allow
extension of Moore's Law for a few more years. This paper provides a new
approach towards the design and modeling of Memristor (Memory resistor) based
Content Addressable Memory (MCAM) using a combination of memristor MOS devices
to form the core of a memory/compare logic cell that forms the building block
of the CAM architecture. The non-volatile characteristic and the nanoscale
geometry together with compatibility of the memristor with CMOS processing
technology increases the packing density, provides for new approaches towards
power management through disabling CAM blocks without loss of stored data,
reduces power dissipation, and has scope for speed improvement as the
technology matures.Comment: 10 pages, 11 figure
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