Kaijian Shi, Principal Consultant, Professional Services, Synopsys
Dave Flynn, Engineering Fellow, Research and Development, ARM

This paper explains in detail various overheads and tradeoffs in power-gating designs. Proven success design guidelines for production of power-gating design will be provided based on extensive power-gating design experience and deep understanding of the nature of the power-gating design. Switch cell design and implementations, as well as various power-gating strategies and corresponding switch cell implementation methods, will be discussed in detail with recommendations. The paper also addresses power integrity of the power-gating designs when the design is in normal operation where the IR–drop and EM constraints must be analyzed and met switch considerations of the switch cells in the power supply network. It describes how to optimize the switch cells and power-gating network to minimize the area and power overheads while meeting IR–drop and EM targets. It also addresses various wakeup control strategies and design implementations, including multi-daisy chain and programmable wakeup control designs.