Arithmetic for digital neural networks

The implementation of large input digital neurons using designs based on parallel counters is described. The implementation of the design uses a two-cell library, in which each cell is implemented using switching trees which are pipelined binary trees of n-channel transistors. Results obtained from initial switching trees realized with a 3-μm CMOS process indicate that the design is capable of being pipelined at 40 MHz sample rates, with better performance expected for more advanced technologies. It appears feasible to develop a wafer-scale implementation with 2000 neurons (each with 1000 inputs) that would perform 3×10¹² additions/s