Cut-demand based routing resource allocation and consolidation for routability enhancement

To successfully route a design, one essential requirement is to allocate sufficient routing resources. In this paper, we show that allocating routing resources based on horizontal and vertical (H/V) cut-demands can greatly improve routability especially for designs with thin areas. We then derive methods to predict the maximum H/V cut-demands and propose two cut-demand based approaches, one is to allocate routing resources considering the maximum H/V cut-demands and the other is to consolidate fragmented metal-1 routing resources for effective resource utilization. Experimental results demonstrate that the resource allocation method can precisely determine design areas and the resource consolidation method can significantly improve routability. With better routability, the routing time is about 5 times faster on average and the design area can be further reduced by 2-15%.