SYSTEMS, METHODS, AND DEVICES WITH WRITE OPTIMIZATION IN PHASE CHANGE MEMORY

摘要

Methods and systems for phase change memories and arrays with improved write characteristics. If a data word can be more efficiently written by e.g. exchanging SETs and RESETs, it is written as such on the fly, and e.g. a bit of overhead is written to indicate the transformation. This has a surprising synergy with phase change memory as SET operations usually take longer and consume more power than do RESET operations. In one sample embodiment of multilevel phase change memory, states intermediate between SET and RESET can be even less desirable to write than SETs, as they take more precision than do the extreme states of SET and RESET, so that a desirable transformation can be to exchange intermediate states for extreme states.