VLSI circuits of the 45-nm technology and beyond are increasingly affected by process variations as well as aging effects. Overcoming the variations inevitably requires additional power expense, which in turn aggravates the power and heat problem. Adaptive Supply Voltage (ASV) is an arguably power efficient approach for variation resilience since it attempts to allocate power resources only to where the negative effect of variations is strong. In this paper, the authors propose a ASV system for designs containing many timing critical paths. This system can simultaneously provide ASV at both coarse-grained and fine grained levels, and has limited power routing overhead.