Using CAD Tools in the Design of CRISP

CRISP is a high-performance 32-bit RISC microprocessor that uses 172,163 transistors in a 1.75¿m CMOS technology. The large chip size of 10.35 mmx 12.23 mm and complexity of the design required an extensive top-down approach in a set of integrated design tools. CAD tools ranged from an instruction set interpreter to detailed timing simulation. Practical problems encountered include communication among different tools and limits on process size, file size, and total compute time. Use of both symbolic compaction and physical layout, while improving initial efficiency, created problems later in the design.