Semicustom and custom LSI technology

Semicustom and custom LSIs have become very important for system manufacturers because they provide system products with distinctive features that cannot be furnished by using only standard LSIs such as microprocessors. From this point of view, 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. In this paper, these aspects for semicustom and custom LSI development are discussed. We first review the device technology and then discuss various design methodologies with an emphasis on standard cell designs. New design methodologies, such as silicon compilers and AI approaches, are also included.