Register binding based power management for high-level synthesis of control-flow intensive behaviors

A circuit or circuit component that does not contain any spurious switching activity, i.e., activity that is not required by its specified functionality, is called perfectly power managed (PPM). We present a general sufficient condition for register binding to ensure that a given set of functional units is PPM. This condition not only applies to data-flow intensive (DFI) behaviors but also to control-flow intensive (CFI) behaviors. It leads to a straightforward power-managed (PM) register binding algorithm. The proposed algorithm is independent of the functional unit binding and scheduling algorithms. Hence, it can be easily incorporated into existing high-level synthesis systems. For the benchmarks we experimented with, an average 45.9% power reduction was achieved by our method at the cost of 7.7% average area overhead, compared to power-optimized register-transfer level (RTL) circuits which did not use PM register binding.