Synapse string array architectures for neural networks

Abstract

A synapse string includes first and second cell strings each having a plurality of memory cell elements connected in series and first switch elements connected to first or second ends of the first and second cell strings, respectively. The memory cell elements of the first cell string and the memory cell elements of the second cell string are in a one-to-one correspondence, and a pair of the memory cell elements being in a one-to-one correspondence has terminals to which a read voltage is applied connected to each other to constitute one synapse morphic element, so that the synapse string includes a plurality of synapse morphic elements connected in series. A synapse string array architecture enables forward propagation and backward propagation by implementing high-density synapse strings, so that the synapse string array architecture can be applied to a neural network capable of inferencing and on-chip learning, along with inference and recognition.