3-D Floorplanning Using Labeled Tree And Dual Sequences

3-D packing is an NP-hard problem with wide applications in microelectronic circuit design such as 3-D packaging, 3-D VLSI placement and dynamically reconfigurable FGPA design. We present a complete representation for general non-slicing 3-D floorplan or packing structures, which uses a labeled tree and dual sequences. For each compact placement, there is a corresponding encoding. The number of possible tree-sequence combinations is (n + 1)(n-1)(n !)(2), the lowest among complete 3-D representations up to date. The construction of placement from an encoding needs O(n(2)) in the worst case, but in practical cases we expect O(n(4/3) log n) time on average for circuit blocks with limited length/width ratios. Experimental results show promising performance using the labeled tree and dual sequences on 3-D floorplan and placement optimizations.