VAST-LP: clock gating in high-level synthesis
Zelei Sun · Illinois Digital Environment for Access to Learning and Scholarship (University of Illinois at Urbana-Champaign) · 2016
High-level synthesis (HLS) promises high-quality hardware with minimal develop- ment e ort. In this thesis, we evaluate the current state-of-the-art HLS engine VAST and propose a method to generate clock-gating-friendly RTL code for downstream logic synthesis tools. We use one-hot-key encoding method to build the state tran- sition in hardware, and we use the state registers along with main clock signal to generate subclock signals. By analyzing the usage of each register when the nite state machine is in di erent states, we assign the corresponding subclock signals to the register and reduce the unnecessary toggle of the registers when they are not in use. CHStone benchmarks in di erent application categories are used to verify the functionality and test the performance of the designs. The area and power data are measured using downstream commercial state-of-the-art tools during logic synthesis. We gain 5% to 20% dynamic power saving with -6% to 2% area increase.