Register binding for clock period minimization

Abstract

In modern high-speed circuit design, the clock skew has been widely utilized as a manageable resource to improve the circuit performance. However, in high-level synthesis stage, the circuit is never optimized for the utilization of clock skew. This paper is the first attempt to the high-level synthesis of non-zero clock skew circuits. First, we show that the register binding in high-level synthesis stage has a significant impact on the clocking constraints between registers. As a result, different register binding solutions lead to different smallest feasible clock periods. Then, based on that observation, we formulate the problem of register binding for clock period minimization. Given a constraint on the number of registers, our objective is to find a minimum-period register binding solution. Experimental data show that, in most benchmark circuits, the lower bound of the clock period can be achieved without any extra overhead on the number of registers.