MGX: An Integrated Symbolic Layout System for VLSI

A symbolic layout system for double-metal silicon-gate MOS technology in the style of Gate Matrix is presented. This system provides an integrated layout environment which consists of stick-figure-based graphic editor, a mask artwork generator, a connectivity checker, a circuit parameter extracter and simulator interfaces. All the modules are designed to deal with symbol data, rather than mask artwork, so that fast execution is realized. A method to associate symbol data with actual mask geometry is described along with the data structure employed. Also described is network partitioning by signal names taking into account logical equivalence of transistor circuits.