YACR: Pattern Routing
- Performs normal LEA, track assignment for nets that do not violate vertical constraints
- Connect remaining trunks using “maze router” (actually pattern router)
- Three patterns: Maze_1 (route under), Maze_2 (one dogleg), Maze_3 (two doglegs)
- If patterns fail, add track
- Will add end columns, if needed, to resolve otherwise impossible cyclic constraints in VCG