CGAL - A Multi Technology Gate Array Layout System

This paper describes the Computerized Gate Array Layout system (CGAL), a general purpose cool developed at Sperry Univac to provide efficient and reliable automated layouts for a variety of master slice arrays. The system contains algorithms for the construction of initial placement, placement improvement, global routing, channel routing and planar routing. The system also provides for user interaction through a design language and graphical output. A wide range of device types encompassing significantly different cell topologies and complexity are presently in production use. Some of the problems encountered are discussed and results are presented for different technologies.