Cooperative Encoding Strategy for Gate Array Placement on Integrated Circuits

With the rapid development of nanometer submicron technology, a delay from those related interconnect becomes the dominant factor of a chip performance. In recent years, the quadratic force-directed placement is becoming popular due to its stable quality at low power. The force-directed placement composes of two operations, namely, orientating and modulating. The two actions are going on until the overlap degree can meet a predetermined target. Different methods have a great influence on their quality of a layout. The article suggests a novel encoding strategy of two-dimensional chromosome based on Immune Cooperative Optimization. The main works first focus on that a multi-point crossover strategy, and its Poisson distribution makes use of a density Euclidean distance between the concentration of antibody suppression and the translation variation of optimal gene pair in two-dimension. Then a flexible region division is proposed for dealing with the layout problem of gate array. The result obtained through those comparative simulations and a related experiment indicates the constructed encoding strategy for gate array placement is effective and efficient.