Threshold logic

A threshold gate has binary inputs and outputs just like any other logic gate. The difference, however, is that in the threshold gate the inputs may be weighted and, eventually, a binary decision made as to whether the total weight is more or less than some reference. This principle of weighting and summing the inputs rather than simply noting the presence of all inputs as high (as in an AND gate) or one input high (as in an OR gate) is the reason that a threshold gate can tell more about the state of the inputs, thus providing greater ``logic power.´´ This article gives some examples of the applicability of threshold logic, as well as an integrated-circuit approach for building arrays of versatile threshold gates. In addition, some logic designs are described and compared with conventional ECL implementations.