Understanding the NAND flash memory channel has become more and more challenging due to the continually increasing density and the complex distortions arising from the write and read mechanisms. In this work, we propose a data-driven generative modeling method to characterize the flash memory channel. The learned model can reconstruct the read voltage from an individual memory cell based on the program levels of the cell and its surrounding array of cells. Experimental results show that the statistical distribution of the reconstructed read voltages accurately reflects the measured distribution on a commercial flash memory chip, both qualitatively and as quantified by the total variation distance. Moreover, we observe that the learned model can capture precise inter-cell interference (ICI) effects, as verified by comparison of the error probabilities of specific patterns in wordlines and bitlines.
翻译:了解NAND闪存信道变得越来越困难,因为书写和读写机制产生的密度不断提高和复杂扭曲。在这项工作中,我们提出一种数据驱动的基因模型方法来描述闪存通道的特点。学习的模型可以根据细胞的程序水平及其周围的细胞阵列来重建单个记忆细胞的读电压。实验结果显示,经过重建的读电压的统计分布准确地反映了商业闪存芯的测量分布,既有质量上的,也有以总变异距离量化的。此外,我们注意到,通过比较文字线和位线上具体模式的错误概率,所学的模型可以捕捉到精确的细胞间干扰效应。