IRWIN AND JOAN JACOBS CENTER FOR COMMUNICATION AND INFORMATION TECHNOLOGIES Information-Theoretic Sneak- Path Mitigation in Memristor Crossbar Arrays

In a memristor crossbar array, functioning as a memory array, a memristor is positioned on each row-column intersection, and its resistance, low or high, represents two logical states. The state of every memristor can be sensed by the current flowing through the memristor. In this work, we study the sneak path problem in crossbar arrays, in which current can sneak through other cells, resulting in reading a wrong state of the memristor. Our main contributions are modeling the error channel induced by sneak paths, a new characterization of arrays free of sneak paths, and efficient methods to read the array cells while avoiding sneak paths. To each read method we match a constraint on the array content that guarantees sneak-path free readout, and determine the resulting capacity. Index Terms Codes for memories, sneak paths, constraint codes, Z channel, memristors, resistive memories, crossbar arrays.