Research in Design Automation for VLSI Layout

Since Japanese R&D efforts began in the late 1960s, advances in LSI circuit design automation have made possible the design of custom logic VLSI circuits with up to 10,000 gates. Automatic placement and routing programs have become essential DA tools in both master-slice LSI circuit design, and the custom design of VLSI circuits with up to 100,000 gates. Algorithms for VLSI DA systems include automatic floor planning, automatic cell placement, and automatic routing. Hierarchical design is an efficient approach to the layour of huge numbers of transistors; a VLSI circuit with 74,000 transistors and 17,000 gates was designed using such an approach. The layout design effort required less than 10 man-months, and the chip was fabricated with no error on the first design.