Keep it straight: teaching placement how to better handle designs with datapaths

As technology scales and frequency increases, a new design style is emerging, referred to as hybrid designs, which contain a mixture of random logic and datapath standard cell components. This work begins by demonstrating that conventional Half-Perimeter Wire Length (HPWL)-driven placers under-perform in terms of regularity and Steiner Wire Length (StWL) for such hybrid designs, and the quality gap between manual placement and automatic placers is more pronounced as the designs become more datapath-oriented. Then, a new unified placement flow that simultaneously handles random logic and datapath standard cells is proposed that significantly improves the placement quality of the datapath while leveraging the speed of modern state-of-the-art placement algorithms. The placement flow is built on top of a leading academic forcedirected placer. It consists of a series of novel global and detailed placement techniques, collectively called Structure Aware Placement Techniques (SAPT). The ...

• Type: Journal
• Year: 2012
• Where: ISPD
• Authors: Samuel I. Ward, Myung-Chul Kim, Natarajan Viswanathan, Zhuo Li, Charles J. Alpert, Earl E. Swartzlander Jr., David Z. Pan
• Keywords: Alignment Constraints, Hardware, Integrated Circuits Design, ISPD 2012, Quality Gap