Semicustom and custom LSI technology

Contrasting marketplace forces have made semicustom LSIs very important to systems manufacturers: systems products enjoy high performance and low cost by incorporating standard devices while they establish their uniqueness by incorporating semicustom LSIs. Rapid development is essential for semicustom and custom LSIs, but there are other factors to be considered for determining the device technology and design methodology, such as performance requirements, allowable development costs, and production quantities. Device technologies are reviewed (CMOS, bipolar, ECL, CML, gallium arsenide, Josephson junctions, integrated injection logic, and multilayer wiring among them). Design methodologies are discussed with emphasis on standard cell designs. New design methodologies, such as silicon compilers and AI (expert system) approaches, are also included.