Body Bias Control on a CGRA based on Convex Optimization

Body biasing is one of the critical techniques to realize more energy-efficient computing with reconfigurable devices, such as Coarse-Grained Reconfigurable Architectures (CGRAs). Its benefit depends on the control granularity, whereas fine-grained control makes it challenging to find the best body bias voltage for each domain due to the complexity of the optimization problem. This work reformulates the optimization problem and introduces continuous relaxation to solve it faster than previous work. Experimental result shows the proposed method can solve the problem within 0.5 sec for all benchmarks in any conditions and demonstrates up to 5.65x speed-up compared to the previous method with negligible loss of accuracy.