A Generalized Approach to Implement Efficient CMOS-Based Threshold Logic Functions

An integer linear programming-based framework to identify the current-mode threshold logic functions is presented. The approach minimizes the transistor count and benefits from a generalized definition of threshold logic functions. It is shown that the threshold logic functions can be implemented in CMOS-based current mode logic with reduced transistor count when the input weights are not restricted to be integers. A novel implementation of rational weights is proposed. Process variations, transistor aging, and circuit parasitics are taken into consideration. Experimental results show that many more functions can be implemented with predetermined hardware overhead, and the hardware requirement of a large percentage of the existing threshold functions is reduced when comparing with the traditional CMOS-based threshold logic implementation.