A novel band-symmetric equation formulation method for BUS interconnect circuits

In high-speed, deep sub-micron ULSI (Ultra Large Scale Integrated) circuit design, the performance of the whole chip is dominated by the interconnect circuits. Because the number of the interconnect components is prohibitively large, fast simulation of interconnect circuits has become crucial to check signal integrity and ensure circuit performance. BUS wires are typical interconnects widely used in ULSI chips. In this paper, a novel method is proposed for the equation formulation of BUS interconnect circuits. Band-symmetric matrices of the system equations are formulated by taking advantage of the parallel structure of the BUS interconnects. Compared to the conventional modified nodal equation formulation method, the proposed method can remarkably improve the simulation speed of the BUS interconnects. The proposed method can be easily applied to circuit simulation tools such as SPICE, PRIMA, PVL, etc., for the interconnect simulations.