Design of a power-gating structure with high performance in the active mode and low leakage and short wakeup time during standby mode is an important and challenging task. A new tri-modal switch cell is presented in this paper that enables implementation of multi-modal power gating, including active, data-retentive drowsy, and deep sleep modes. In this paper, we also present a novel integrated circuit and architectural-level technique for general pipeline designs that enables us to benefit from ultra low leakage deep sleep mode, low leakage but very fast wakeup drowsy mode, and an additional low leakage data-retentive mode. We propose a novel tri-modal switch cell that enables us to realize this circuit architecture.