Low-power domino circuits using NMOS pull-up on off-critical paths

Domino logic is used extensively in high speed microprocessor datapath design. Although domino gates have small propagation delay, they consume relatively more power. We propose a scheme to reduce the power consumption of combinational domino logic blocks while maintaining the performance. We replace the PMOS precharge transistor with an NMOS transistor to reduce the overall power consumption of the gate at the expense of higher delay. We use a heuristic algorithm to replace the fast, high power gates on the off-critical paths with slower, low power gates while maintaining the circuit performance. Our technique reduces dynamic energy of ISCAS ´85 circuits by 16.25%.