3-D Global Routing with Layer Directive and Scenic Constraints

Zhongdong Qi,  Yici Cai,  Qiang Zhou,  Zhuwei Chen
Tsinghua University


Abstract

As technology advances, modern physical synthesis flows pose layer directive and scenic constraints to global routing. Respecting these constraints in global routing is critical to achieve timing closure for designs. In this paper, we propose a 3-D global routing algorithm which simultaneously respects layer directive constraints and scenic constraints. We develop layer directive and scenic constrained A* routing algorithm. Layer directive and scenic constraints can be strictly obeyed during path searching. Experimental results demonstrate that layer directive and scenic constraints can be obeyed successfully, with small increase of via number and runtime.