Writing without Disturb on Phase Change Memories by Integrating Coding and Layout Design

Abstract

We integrate coding techniques and layout design to eliminate write-disturb in phase change memories (PCMs), while enhancing lifetime and host-visible capacity. We first propose a checkerboard configuration for cell layout to eliminate write-disturb while doubling the memory lifetime. We then introduce two methods to jointly design Write-Once-Memory (WOM) codes and layout. The first WOM-layout design improves the lifetime by more than double without compromising the host-visible capacity. The second design applies WOM codes to even more dense layouts to achieve both lifetime and capacity gains. The constructions demonstrate that substantial improvements to lifetime and host-visible capacity are possible by co-designing coding and cell layout in PCM.