Glitch-aware variable pipeline optimization for CGRAs

Although some coarse grained reconfigurable arrays (CGRAs) have a function to unify multiple processing elements (PEs) to enhance the energy efficiency, it sometimes causes propagation of glitches widely resulting in the power increases. We propose a dynamic power model considering glitches and an optimization technique using it for CGRAs. The model aims to estimate the energy consumption from the switching counts of a PE array approximately. The model and optimization were applied to a real chip of the low power CGRA called the VPCMA (Variable Pipeline Cool Mega Array). Compared with the energy estimation with a post-layout simulation, the model could estimate it with more than 10000 times faster with smaller error from the results of the real chip measurement. The optimized pipeline structure using the proposed method achived better energy consumption compared to fixed pitch pipeline structures in most cases.