LTX-A system for the directed automatic design of LSI circuits

LTX is a minicomputer-based design system for largescale integrated circuit chip layout which offers a flexible set of interactive and automatic procedures for translating a circuit connectivity description into a finished mask design. The system encompasses algorithms for two-dimensional placement, string placement, exploitation of equivalent terminals, decomposition of routing into channels, and channel routing. Circuit connectivity is preserved during interactive procedures. LTX runs on an H-P 2100 series computer with 32K of memory and disc. In current applications to polycell-style layouts, one to two weeks is typically required for completion of the layout design of an LSI chip containing 500 cells.