Detailed routing in a hierachical CPLD

We describe the detailed routing of a commercial complex programmable logic device (CPLD). The hierarchical, course-grained architecture of the CPLD lends itself to a novel hybrid router that combines a negotiated maze-router with a flow-based router. Numerical results illustrate that our router is significantly faster than a flat maze-router. It also has a higher completion rate compared to a commercial router while producing routings of comparable quality.