Unified Quadratic Programming Approach For 3-D Mixed Mode Placement

An efficient analytical 3D placement algorithm for mixed-mode placement is presented, which consists of 3D global placement and detailed placement. In global placement, wire length and cell division are unified into a quadratic objective function. It takes advantage of quadratic programming to optimize the unified objective efficiently. 3D discrete cosine transformation (DCT) is introduced to help divide cells into different layers. The number of vertical vias gets better controlled during global placement and a new method to optimize cell division after global placement is presented. For detailed placement, we traverse 3D to 2D by net decomposition and finish detailed placement by network flow algorithm. Experimental results show that the 3D placement algorithm is very promising.