Locally Mitigating Sneak-Path Interference in Resistive Memory Arrays

In this work, we propose efficient constrained coding schemes to significantly reduce the sneak path interference (SPI), a fundamental and challenging problem, in crossbar resistive memory arrays. Particularly, we attempt to combat the sneak path effect locally as follows. For arrays of size n × n, we study coding methods that enforce every sliding window of size m×m (where each window refers to a subarray consisting of consecutive rows and consecutive columns), for some m < n to be either:•(m,δ)-bounded-weight: the number of 1’s in every sliding window is at most m
²
/2 − δ for δ ⩾ 0, and this constraint is called the locally bounded-weight constraint, or•Sneak-path-free: the written bits in every window do not induce any sneak path to any cell, and this constraint is called the locally sneak-path-free constraint.In this work, we study the maximum information rate that can be achieved (or channel capacity) and design codes for each constraint. Particularly, for the first constraint, for arbitrary m ⩾ 4 and$\delta \leq m\left( {\sqrt m /2 - 1} \right) = \Theta \left( {m\sqrt m } \right)$, we provide an efficient construction of codes with the code rate 1 − 2/$\sqrt m $, while the highest rate found in the prior art is approximately 1 − 1/m, which was only applicable for m = n − o(n) and δ = 0.