Implementation of time-aware sensing technique for multilevel phase change memory cell

Abstract

This paper introduces and tests a time-aware sensing scheme to overcome the drift issue in Multi-Level Phase Change Memory (MLPCM). Adaptive resistance thresholds are calculated based on statistical data to generate timely reference levels for comparison. Simulations are carried out utilizing MLPCM cell model that mimics the physical behavior of MLPCM cell. The simulation results were then compared against experimental data, and it was noted that simulation results of the used MLPCM model are in close agreement with the experimental data. Furthermore, the time aware sensing scheme provided an accurate reading of the stored bit values given that the timely reference levels successfully compensated for the drift phenomenon. Finally, an application of time aware sensing coupled with MLPCM was implemented, where MPLCM is used as memory element in a Look Up Table (LUT). The suggested MLPCM based LUT utilizes the density and reliability offered by MLPCM paired with the presented time aware sensing scheme.