Orientation assignment of standard cells using a fuzzy mathematical transformation

It is well known that minimising total wire length reduces routing area in a standard cell layout. After the placement phase, another advanced improvement on total wire length is made by assigning the orientations of standard cells. The authors develop two way constrained fuzzy graph clustering based on fuzzy c-means clustering and the transformation between the orientation assignment of standard cells and the constrained graph bisection to minimise total wire length. Finally, the proposed algorithm has tested several standard cell layouts, and the experimental results show that the proposed algorithm produces significant wire reduction on total wire length