Multi-precision digital compute-in-memory deep neural network engine for flexible and energy efficient inferencing

Abstract

Anon-volatile memory structure capable of storing weights for layers of a deep neural network (DNN) and perform an inferencing operation within the structure is presented. An in-array multiplication can be performed between multi-bit valued inputs, or activations, for a layer of the DNN and multi-bit valued weights of the layer. Each bit of a weight value is stored in a binary valued memory cell of the memory array and each bit of the input is applied as a binary input to a word line of the array for the multiplication of the input with the weight. To perform a multiply and accumulate operation, the results of the multiplications are accumulated by adders connected to sense amplifiers along the bit lines of the array. The adders can be configured to multiple levels of precision, so that the same structure can accommodate weights and activations of 8-bit, 4-bit, and 2-bit precision.