The Star-Routing Algorithm Based on Manhattan-Diagonal Model for Three Layers Channel Routing

In this paper, we employ gridded model for channel routing and place the terminals which are horizontally aligned. We have developed a two-layer channel router that can eliminate the constraints due to overlap. The proposed approach is suitable for cell/IP-based channel-less circuit with a few channels. Our developed tool can route the nets in nearly linear time achieving to the advantage of time to market, and lead to the area overhead of 6.34% increase in average. The area overhead results from the space insertion, and we also have shown that the proposed algorithm can achieve 100% routing on most ISCAS’85 benchmarks. In addition, the number of channel tracks can be minimized by our algorithm. We proposed the star-routing algorithm for three layers channel routing using Manhattan-Diagonal Model to solve the channel routing problem. We drew up the smaller grid-model, and in order to avoid violating the DRC, so the algorithm has a restriction for the third metal-layer in routing step. We don’t need to increasing extra spaces and moving any pins in order to finish the routing completely. The foregoing is good for hard blocks to finish the routing easily, and it does not replace the location of hard blocks because of routing incompletely. Therefore, the height of the entire routing channel can reduce a lot. Key-Words: Channel routing, Manhattan-Diagonal Model, Electronic Design Automation (EDA)