Systems and methods for operating logic circuits

摘要

Systems and methods for reducing the power consumption of some combinations of logic gates by reducing the number of unnecessary transitions that are made by logic gates that do not affect the output of the logic. In one embodiment, a modified exclusive-OR (XOR) gate is coupled to a modified multiplexer. The XOR gate has two inputs, A_in and B_in, and an output, XOR_out, which is provided as an input to the multiplexer. Another input to the multiplexer is C_in. A select signal is input to the multiplexer to select either C_in or XOR_out to be provided at the output of the multiplexer. If XOR_out is selected, the XOR gate operates in a first mode in which it functions as a normal XOR gate. If C_in is selected, the XOR gate operates in a second mode in which the XOR gate uses less power than when the XOR gate operates normally.