In this paper, we consider the two row maximum planar subset (TRMPS) problem in over-the-cell routing. The TRMPS problem requires selection of the maximum planar subset of nets, which can be routed between two rows of terminals in a cell row. This problem was first encountered by Gong, Liu, and Preas (1990). They stated the complexity of this problem to be unknown, and presented a min {1,k/d(S)} approximation algorithm, where k is the number of tracks available over the cell area and d(S) is the density of a solution S. We show that TRMPS problem can be solved optimally in polynomial time. We present a O(kn/sup 2/) dynamic programming algorithm for the TRMPS problem, where n is the number of nets. We also present a parallel version of our algorithm, which has a complexity of O(kn). Our algorithm can also be extended to solve the TRMPS problem, in the presence of prerouted nets, a chosen subset of nets, as well as for planar channel routing. We also apply our technique to obtain a 0.5 approximation, for over the cell routing in middle terminal model, thus improving the best known existing algorithm. The weighted version of the TRMPS problem, as well as, all the extensions can also be solved in O(kn/sup 2/) time.

In this paper we solve the planar over-the-cell routing problem, in which nets must have at least one terminal on the boundary. Such nets allow for nontraditional cell designs, where all terminals must be placed on the boundaries giving a degree of freedom to the cell designer. We present a dynamic programming algorithm that optimally solves this problem, in O(K/sup 2/n/sup 4/) time, where K is the number of tracks available over the cell for a given cell row region, and n is the number of nets to be routed.

The Two Row Maximum Planar Subset (TRMPS) problem asks for finding the maximum planar subset of nets, that can be routed between two rows of terminals an a cell row. This problem was first encountered by Gong, Liu, and Preas (1990). They declared it open, and presented an approximation algorithm for this problem. In this paper we show that TRMPS problem can be solved optimally in polynomial time, and we present an O(kn/sup 2/) algorithm to solve this problem. Our algorithm can also be extended to solve the TRMPS problem, in the presence of pre-routed nets, a chosen subset of nets, as well as for planar channel routing. We also apply our technique to obtain an improved approximation algorithm, for over the cell routing in middle terminal model standard cell layouts.>

In this paper, we present ARCHITECT, the floorplanner for high performance Mixed Block and Cell designs. A novel and significant feature of ARCHITECT is that it exploits the flexibility of the standard cell regions by generating arbitrary rectilinear shapes for the flexible blocks. We have implemented ARCHITECT on a Sun SPARC station 1+ using C and Xview. We have tested the floorplanner on various randomly generated examples. Experimental results indicate that ARCHITECT generates floorplans with minimal white space within the user specified bounds.>