Localized logic regions of a circuit include a local comparator electrically connected to a local resistive voltage circuit, to a local resistive ground circuit, and to a local register structure. The local comparator supplies a clock pulse to the local register structures when the local reference voltage is below a local voltage threshold. Activity in the local combinatorial logic structure causes the local reference voltage to drop below the local reference voltage independently of changes in the global reference voltage causing the comparator to output the clock pulse (with sufficient delay to allow the logic results to be stored in the registers only after setup times have been met in the local logic devices). This eliminates the need for a clock distribution tree, thereby saving power when there is no activity in the local combinatorial logic structure.