Method and apparatus for reducing power consumption in VLSI circuit designs

In integrated circuit (IC) designs, a component of power consumed may be represented as Power= FCV2, where C is the load capacitance being driven by a source cell, F is the switching frequency of the source cell, and V is the total output voltage swing. However, not every signal value generated by a source cell is required to propagate to all the sink cells connected to the source for every clock cycle of a chip. Accordingly, an isolate cell is inserted in a net (wire) connecting a source cell to at least one sink cell, to de-couple the at least one sink cell and a portion of the net from the source cell when a signal output by the source need not propagate. Due to the de-coupling, the load capacitance associated with the at least one sink and net portion is not experienced by the source cell for such signals. Accordingly, overall IC power consumption is reduced In integrated circuit (IC) designs, a component of power consumed may be represented as Power=½ FCV2, where C is the load capacitance being driven by a source cell, F is the switching frequency of the source cell, and V is the total output voltage swing. However, not every signal value generated by a source cell is required to propagate to all the sink cells connected to the source for every clock cycle of a chip. Accordingly, an isolate cell is inserted in a net (wire) connecting a source cell to at least one sink cell, to de-couple the at least one sink cell and a portion of the net from the source cell when a signal output by the source need not propagate. Due to the de-coupling, the load capacitance associated with the at least one sink and net portion is not experienced by the source cell for such signals. Accordingly, overall IC power consumption is reduced.