Controlling-value-based power gating considering controllability propagation and power-off probability

Power gating technology is useful in reducing standby leakage current. Controlling value based power gating is a fine-grained power gating approach using the controlling value of logic elements. However, power saving capability suffers from the steady maximum depth constraint, which prohibits the power gating assignment when the control of a gate increases the critical path length. To increase power savings, this paper proposes a power gating control extraction method based on controllability propagation and power-off probability. Multiple power domains can be clustered by a smaller depth signal with the controllability propagation. Experimental results show that 21.4% power reduction can be obtained in average, achieving 8.5% improvement compared with previous algorithm.