Power Gating with Multiple Sleep Modes

This paper describes a power gating technique with multiple sleep modes where each mode represents a trade-off between wake-up overhead and leakage savings. We show that high wake-up latency and wake-up power penalty of traditional power gating limits its application to large stretches of inactivity. Our simulations and data traces show that multiple sleep mode capability provides an extra 17% reduction in overall leakage as compared to single mode gating. The multiple modes can be designed to allow state-retentive modes. The results on benchmarks show that a single state-retentive mode can reduce leakage by 19% while preserving state of the circuit