A new paradigm for synthesis and propagation of clock gating conditions

Clock gating has become a standard practice for saving dynamic power in the clock network. Due to design reuse, it is common to find designs that have already some partial clock gating. We propose to exploit the existing clock gating in order to extract stronger gating conditions for blocks that are poorly gated or not gated at all. A second contribution of our paper is a robust and scalable approach to extract stability conditions for clock gating. Finally, we present a uniform treatment of unobservability and stability as dual approaches for propagating gating conditions forward and backward. Experimental results demonstrate significant power reduction (in the range of 14% - 55% of the clock power) on Intel micro-processor designs.