Pulsed-latch aware placement for timing-integrity optimization

Utilizing pulsed latches in a circuit is one emerging solution to timing improvements. Pulsed latches, driven by a brief clock signal generated from pulse generators, possess superior design parameters over flip-flops. If pulse generators and pulsed latches are not placed properly, however, pulse-width degradations at pulsed latches and thus timing violations might occur. In this paper, we introduce the pulsed-latch aware placement problem for timing integrity and present a unified placement framework to tackle this problem. Our new placer has the following distinguished features: (1) a multilevel pulsed-latch aware analytical placement framework to effectively prevent the potential pulse-width distortion problem, (2) a physical-information aware latch grouping algorithm to identify each desired group of a pulse generator and pulsed latches, and (3) a new optimization gradient for global placement to consider the impact of load capacitance of generators. Experimental results show that our placement flow can effectively consider pulse-width integrity and thus achieve much smaller total/worst negative slacks with marginal wirelength overheads, compared to a leading commercial and an academic placement flows.