AGENTS: A Distributed Client-Server System for Leaf Cell Generation

These servers communicate over a computer network using the TCP/IP Internet Protocol. The Placer server receives from its client the description and netlist of the circuit to be generated using EDIF (Electronic Design Interchange Format). The output to its client is the mask layout of the circuit, again codified in EDIF. The concept of agents as software components which have the ability to communicate and cooperate with each other is at the heart of the AGENTS system. This concept is not only used at the higher level, for the four servers, but at a lower level as well, inside the Router and Placer servers, where small relatively simple agents work together to accomplish complex tasks. These small agents are responsible for all the reasoning carried out by the two servers, as they hold the basic inference routines and the knowledge needed by the servers. The system’s philosophy is that competence should emerge out of the collective behavior of a large number of relatively simple agents. In addition and integrated to these small agents, the system uses a genetic algorithm to improve components’ placement before routing.