LEGAL: An algorithm for simultaneous net routing

This, paper presents LEGAL, a new routing algorithm that may be specially interesting for area routing problems. It is a generalization of two of the most important channel routing techniques, Left-Edge [3] and Greedy [13] algorithms. Area routing is an important problem today due, to the fact that the availability of several metal layers allows all the routing to be done over the cells [15]. Therefore, the circuit is not partitioned into well defined blocks and routing regions anymore. We seek the use of an algorithm that processes all nets simultaneously as an alternative to standard "net by net" routing or independent Global Cells routing. LEGAL is demonstrated to perform efficiently for small problems in three different implementations, generating complete routing solutions in orders of magnitude less time as compared to maze routers.