Security Seminar: Extending the Lifetime of Flash Memory

Armour College of Engineering’s Electrical and Computer Engineering (ECE) Department is announcing a seminar featuring Prof. Robert Calderbank of Duke University. Prof. Calderbank will be presenting his lecture Extending the Lifetime of Flash Memory.

Abstract:

Hard disk drives are losing ground to Flash because they do not support random access, their moving parts consume significant power and they have relatively slow read and write speeds. The recent adoption of non-volatile memory by large data centers is making a particular shortcoming of Flash more visible; the fact that a memory cell can only support a limited number of writes before it fails. Furthermore, this number is expected to decrease significantly as the minimum feature size of Flash transistors shrinks.

In this talk we describe how to extend the lifetime of Flash memory by increasing the number of writes that are possible before erasure is necessary. We introduce redundancy into the write process in order to decrease the number of memory cells that are impacted by a given write, and to even out the impact of writing across an entire page of memory.

We shall write data to memory in the form of a coset of a convolutional code. The coset is represented by a binary vector that is selected by the Viterbi algorithm to minimize the number of cells impacted by the write (Hamming weight) and to even out the number of writes to each cell within a given page. We show that lifetime gains of over 500% are possible with only modest encoding and decoding complexity.

This presentation describes joint work with Adam Jacobvitz, John Marcus and Dan Sorin.

This event will earn you Engineering Themes credit in Security.