IBM AS/400 processor architecture and design methodology

The IBM AS/400 is a family of general purpose mid-range computers specifically designed to run commercial business applications and transaction processing in batch and interactive environments. The April, 1991 announcement is the second generation of the system. It provides a 2.7 times performance improvement over its predecessor. Architectural support for multiprocessors is also part of the product. Achieving this performance improvement required significant changes to the processor architecture, chip technologies and operating system hardware. The architecture and design methodology used in the IBM AS/400 processor are briefly described. The processor chip designs made extensive use of high level hardware description languages and logic synthesis. Each design group was responsible for defining its design in VHDL and converting the design into logic using logic synthesis. The designer's experiences with these new methods are highlighted.<>