Design considerations for the PowerPC 601 microprocessor

The PowerPC 601™ microprocessor (601) is the first member of a family of processors that support IBM's PowerPC Architecture™. The 601 is a general-purpose processor based on a superscalar design point. As with any development effort, the 601 development program had several different, often conflicting, design goals. The most important requirements were support for the PowerPC Architecture, a short development cycle, competitive performance and cost, compatibility with existing POWER applications, and support for mulitprocessing. This paper describes several aspects of the 601 design and discusses some of the design trade-offs considered in those areas.