A fast simultaneous input vector generation and gate replacement algorithm for leakage power reduction

Lei Cheng, Liang Deng, Deming Chen, Martin D. F. Wong

Abstract: Input vector control (IVC) technique is based on the observation that the leakage current in a CMOS logic gate depends on the gate input state, and a good input vector is able to minimize the leakage when the circuit is in the sleep mode. The gate replacement technique is a very effective method to further reduce the leakage current. In this paper, we propose a fast algorithm to find a low leakage input vector with simultaneous gate replacement. Results on MCNC91 benchmark circuits show that our algorithm produces $14 %$ better leakage current reduction with several orders of magnitude speedup in runtime for large circuits compared to the previous state-of-the-art algorithm. In particular, the average runtime for the ten largest combinational circuits has been dramatically reduced from 1879 seconds to 0.34 seconds.