Standard Cell Layout Generator Amenable to Design Technology Co-Optimization in Advanced Process Nodes
Handong Cho, Hyunbae Seo, Sehyeon Chung, Kyu-Myung Choi, Taewhan Kim
Abstract
To generate standard cell (SC) layouts of competitive quality, pin accessibility and in-cell routing congestion should be thoroughly taken into account. In this work, we develop a new tool to address this issue. Precisely, we (1) develop a technology compilation module that can convert diverse cell architectures and design rules into grid based design parameters and layer configuration, (2) generate optimal FET placement using metrics that can accurately and efficiently predict intra-cell pin accessibility and in-cell routing congestion, and (3) introduce the concept of ghost-via and ghost-metal, and formulate in-cell routing using satisfiability modulo theory for pin separation and extension. Experimental results show that our system is able to synthesize SC layouts with a routing completion rate of 95~98 %, which is far better than the previous SC layout generator, and produce layouts comparable to the ARM's hand-crafted layouts. In addition, the design implementations produced by using our 2-layer ID SC library exhibit on average 76.6% fewer design rule violations (DRVs) with similar or better quality of timing and area, while in comparison with that produced by using the library of hand-crafted ARM SCs, the implementations produced by using our L-layer 2D SC library exhibit on average 11.7% smaller area with comparable timing and DRV count.