Investigation and Optimization of Pin Multiplexing in High-Level Synthesis

This paper investigates the effect of pin multiplexing on the resultant micro-architecture of synthesizable behavioral descriptions for High-Level Synthesis (HLS). A method is presented to find the most efficient pin assignments by assigning multiple logic inputs and outputs to the same physical ports such that the performance degradation and area overhead is minimized. The proposed method is a fast heuristic based on the scheduling results of HLS seen as a black box and hence is flexible enough to work with any HLS tool. Experimental results show that our proposed method is very efficient compared to an exhaustive search and a simulated annealing method at a fraction of the time and much better than randomly selecting the pins to be multiplexed.