A field programmable gate array has multiple logic units interconnected via level-0 routing structure to form tier 0 logic tiles. The level-0 routing structure has horizontal wiring and vertical wiring that is interconnected via a horizontal-to-vertical directional routing switch that transfers signals...http://www.google.de/patents/US6094066?utm_source=gb-gplus-sharePatent US6094066 - Tiered routing architecture for field programmable gate arrays
