Properties of Wired Logic

When we design networks with NOR or NAND gates which are implemented with bipolar and MOS transistors, wired logic is usually allowed. The usage of wired logic reduces the network cost and possibly improves the speed because of shorter delays on wired logic than on a gate. Typical logic functions performed by wired logic are AND and OR, which are called wired-AND and wired-OR, respectively. Properties of networks with NOR gates and wired-AND (or wired-OR) are discussed. Some of these properties are used in developing synthesis procedures of optimum networks by the integer programming logic design method. For all three-variable functions, the optimum networks with NOR gates and wired-OR's, designed by this synthesis approach, are shown.