A low-cost realization of multiple-input exclusive-OR gates

Several efficient CMOS two-input exclusive-OR (XOR) logic structures have been reported in the past. Based on these XOR gates, we propose two multiple-input XOR circuit configurations, which are smaller, faster, and run at a lower power level than conventional structures formed by directly connecting two-input XOR gates. For exclusive-OR sum-of-products circuits, four transistors can be saved for each product term.