Date Added: Feb 2010
Dynamic RAM (DRAM) has been the best technology for main memory for over thirty years. In embedded space applications, radiation hardened DRAM is needed because gamma rays cause transient errors; such rad-hard memories are extremely expensive and power hungry, leading to lower life (or increased battery weight) for satellite and other devices operating in space. Despite these problems, DRAM has been the technology of choice because it has better performance and it scales well. New, more energy efficient, non-volatile, scalable, radiation resistant memory technologies are now available, namely Phase-Change Memory (PCM), making the DRAM choice much less compelling. However, current approaches require changes to PCM device internal circuits, the operating system and/or the CPU cache-memory organization/interface.