Wire Congestion And Thermal Aware Global Placement For 3D VLSI Circuits

The recent popularity of 3D IC technology stems from its enhanced performance capabilities and reduced wiring length. However, wire congestion and thermal issues are exacerbated due to the compact nature of these layered technologies. In this paper, we develop techniques to reduce global the temperature gradient and local and global congestions of 3D circuit designs without compromising total intra-layer wirelength or inter-layer via count. Our approach consists of two phases. First, we use a multilevel min-cut based approach with a modified gain function in order to minimize the local wire congestion and power dissipation. Then, we perform simulated annealing with a full-length thermal analysis to reduce the circuit’s global congestion and thermal gradient. Experimental results show that when compared to the standard mincut approach, our thermal gradient and local congestion are reduced by 25% each, global congestion is reduced by over 7%. Moreover, we only see a 10% increase in the wiring length and the number of vias required.