Post-Synthesis Circuit Techniques for Runtime Leakage Reduction

We consider the problem of reducing active mode leakage power by modifying the post-synthesis net lists of combinational logic blocks. The stacking effect is used to reduce leakage power, but instead of a separate signal one of the inputs to the gate itself is used. The approach is studied on multiplier blocks. It is found that a significant number of nets have high probabilities of being constant at 0 or 1. In specific applications such as those having high peak to average ratio, like audio and other signal processing applications, this effect is more pronounced. We show how these signals can be used to put gates to sleep, thus saving significant leakage power.