Abstract: Methods and systems for time-based cell decoding for PCM memory. Generally, the higher the PCM element resistance, the longer it takes for a read output to change state. PCM memory output is determined using differentiated timings of read outputs changing state, rather than differentiated values of read outputs. In some single-bit single-ended sensing embodiments, a reference, with resistance between the resistances corresponding to a pair of adjacent logical states, is stored in multiple reference cells; a “vote” unit emits a clock signal when a majority of the reference cell read outputs transition at the vote unit. Timing units produce different binary outputs depending on whether a data read output or the clock signal changes state first at the timing unit. Time-based decoding provides advantages including improved temperature and drift resilience, improved state discrimination, improved reliability of multibit PCM, and fast and reliable sensing.

Abstract: Methods and systems for time-based cell decoding for PCM memory. Generally, the higher the PCM element resistance, the longer it takes for a read output to change state. PCM memory output is determined using differentiated timings of read outputs changing state, rather than differentiated values of read outputs. In some single-bit single-ended sensing embodiments, a reference, with resistance between the resistances corresponding to a pair of adjacent logical states, is stored in multiple reference cells; a “vote” unit emits a clock signal when a majority of the reference cell read outputs transition at the vote unit. Timing units produce different binary outputs depending on whether a data read output or the clock signal changes state first at the timing unit. Time-based decoding provides advantages including improved temperature and drift resilience, improved state discrimination, improved reliability of multibit PCM, and fast and reliable sensing.

Abstract: Methods and systems for time-based cell decoding for PCM memory. Generally, the higher the PCM element resistance, the longer it takes for a read output to change state. PCM memory output is determined using differentiated timings of read outputs changing state, rather than differentiated values of read outputs. In some single-bit single-ended sensing embodiments, a reference, with resistance between the resistances corresponding to a pair of adjacent logical states, is stored in multiple reference cells; a “vote” unit emits a clock signal when a majority of the reference cell read outputs transition at the vote unit. Timing units produce different binary outputs depending on whether a data read output or the clock signal changes state first at the timing unit. Time-based decoding provides advantages including improved temperature and drift resilience, improved state discrimination, improved reliability of multibit PCM, and fast and reliable sensing.

Abstract: Methods and systems for time-based cell decoding for PCM memory. Generally, the higher the PCM element resistance, the longer it takes for a read output to change state. PCM memory output is determined using differentiated timings of read outputs changing state, rather than differentiated values of read outputs. In some single-bit single-ended sensing embodiments, a reference, with resistance between the resistances corresponding to a pair of adjacent logical states, is stored in multiple reference cells; a “vote” unit emits a clock signal when a majority of the reference cell read outputs transition at the vote unit. Timing units produce different binary outputs depending on whether a data read output or the clock signal changes state first at the timing unit. Time-based decoding provides advantages including improved temperature and drift resilience, improved state discrimination, improved reliability of multibit PCM, and fast and reliable sensing.

Abstract: Methods and systems for multi-bit phase change memories. Using differential sensing for memory reads provides advantages including improved temperature and drift resilience, improved state discrimination and increased storage density.

Abstract: Methods and systems for processors and processing systems having multi-bit phase change memories. Using differential sensing for memory reads provides advantages including improved temperature and drift resilience, improved state discrimination and increased storage density.

Abstract: Methods and systems for multi-bit phase change memories. Using differential sensing for memory reads provides advantages including improved temperature and drift resilience, improved state discrimination and increased storage density.

Abstract: Systems and devices in which multi-bit phase change memory is used, including memory systems and memories, as well as methods for operating such systems and devices. According to the present invention, a reference corresponding to a pair of adjacent logical states (e.g., 0 and 1) can be generated by averaging outputs from multiple phase change memory reference cells designated to store said adjacent logical states. By writing reference cells contemporaneously with words of cells that are configured to be written together, resulting references can closely track output changes in corresponding ones of said words resulting from, e.g., drift and other time- and phase change material-dependent factors. Ordering of states within said reference cells can be used to encode information such as checksums of corresponding words.