Determination of Power Gating Granularity for FPGA Fabric

In this study, we present a design methodology to determine the granularity of power gating for field programmable gate arrays (FPGAs). Fine-grain power gating is more effective than coarse-grain power gating to reduce the active leakage power of unused logic and interconnection resources. However, the area overhead in fine-grain power gating is higher than that of coarse-grain power gating. Based on the placement and routing of benchmark designs in Spartan-3trade-like FPGA, guidelines for determining the granularity of power gating are provided. It is found that programmable resources with low utilization can be power gated more coarsely than the resources with high utilization