Mercury: A fast and energy-efficient multi-level cell based Phase Change Memory system

― Phase Change Memory (PCM) is one of the most promising technologies among emerging non-volatile memories. PCM stores data in crystalline and amorphous phases of the GST material using large differences in their electrical resistivity. Although it is possible to design a high capacity memory system by storing multiple bits at intermediate levels between the highest and lowest resistance states of PCM, it is difficult to obtain the tight distribution required for accurate reading of the data. Moreover, the required programming latency and energy for a Multiple Level PCM (MLC-PCM) cell is not trivial and can act as a major hurdle in adopting multilevel PCM in a high-density memory architecture design. Furthermore, the effect of process variation (PV) on PCM cell exacerbates the variability in necessary programming current and hence the target resistance spread, leading to the demand for high-latency, multi-iteration-based programming-and-verify write schemes for MLC-PCM. PV-aware cont...

• Type: Journal
• Year: 2011
• Where: HPCA
• Authors: Madhura Joshi, Wangyuan Zhang, Tao Li
• Keywords: Distributed And Parallel Computing, HPCA 2011, Phase Change Memory, Process Variation, Programming