A pin permutation algorithm for improving over-the-cell channel routing

A dynamic-programming-based algorithm is presented to determine proper gate and terminal positions such that, when over-the-cell routers are used, the area above and below the channel can be utilized more effectively and the channel density can be greatly reduced. The problem formulation and previous work are discussed. The terminology and notation are introduced. A polynomial-time algorithm is presented. Experimental results showed that the proposed algorithm considerably reduces the channel density.<>