Novel complementary resistive switch crossbar memory write and read schemes

Recent trends in emerging nonvolatile memory systems necessitate efficient read/write (R/W) schemes. Efficient solutions with zero sneak path current, nondestructive R/W operations, minimum area and low power are some of the key requirements. Toward this end, we propose a novel crossbar memory scheme using a configuration row of cells for assisting R/W operations. The proposed write scheme minimizes the overall power consumption compared to the previously proposed write schemes and reduces the state drift problem. We also propose two read schemes, namely, assisted-restoring and self-resetting read. In assisted-restoring scheme, we use the configuration cells which are used in the write scheme, whereas we implement additional circuitry for self-reset which addresses the problem of destructive read. Moreover, by formulating an analytical model of R/W operation, we compare the various schemes. The overhead for the proposed assisted-restoring write/read scheme is an extra redundant row for the given crossbar array. For a typical array size of 200 x 200 the area overhead is about 0.5%, however, there is a 4X improvement in power consumption compared to the recently proposed write schemes. Quantitative analysis of the proposed scheme is analyzed by using simulation and analytical models.