The Standard Transistor Array (STAR) Part II Automatic Cell Placement Techniques

Layout of a STAR device consists of the placement of standard cells (circuit elements) on the array and the routing of conductors between cells. Cell placement must be such that routing is not hindered. Also, placement procedures must be cost effective and easy to implement on a digital computer. A placement procedure for STARs is described in this paper that satisfies these characteristics. The procedure attempts to optimize the placement with respect to several criteria including expected routing channel usage and routing VIA requirements. Computer implementations of the procedure are discussed. Experimental results are presented which indicate that the procedure yields near-optimum results in computationally convenient amounts of time.