Improving Write Performance on Cross-Point RRAM Arrays by Leveraging Multidimensional Non-Uniformity of Cell Effective Voltage

Resistive cross-point memory arrays can be used to construct high-density storage-class memory. However, coupled IR drop and sneak currents cause multidimensional non-uniformity of cell effective voltage in cross-point arrays. The voltage non-uniformity significantly degrades write performance on cross-point memory if only adopting the worst-case write latency at partial dimensions. Furthermore, the non-uniformity of cell effective voltage in cross-point arrays depends on multidimensional dynamic write operation parameters: row, column as well as layer address, the number of selected cells, and the number of half-selected low-resistance state cells. In this article, we aim to improve the write performance by leveraging multidimensional non-uniformity of cell effective voltage. First, we analyze the impact of multidimensional write parameters on effective voltage and write latency. Then, we design the memory array write scheme that measures the write parameters and sets the write latency accordingly. We further analyze the features and effects of interlayer sneak currents and extend the scheme to 3D cross-point memory. The evaluation shows that the proposed memory array write scheme can reduce the memory access latency by 75.6 and 64.1 percent, and improve the system performance by 4.5 times and 3.4 times on average, compared with the baseline and the state-of-the-art approach, respectively.

Duke Scholars

Author Yiran Chen Electrical and Computer Engineering