Designing an Alpha microprocessor

Processor design teams at Digital and now Compaq Computer Corp. have been designing and building microprocessors for about 20 years. For the past 10 years, they have been designing Alpha processors with the goal of maintaining industry-leading performance during each generation. Over time, the teams have developed a process to support this goal. Defining and designing a high-performance processor is high adventure in computer engineering. Nevertheless, this journey into new technologies and the unknown has a well-defined path. The author, a computer architect, shares the process the Alpha design teams use to develop their processors. From early product definition to delivery of the design (tape out) and debug, the article gives an insider's view of the steps in building a microprocessor. It also gives a glimpse of what it's like to work on such a project. The author sees the most striking and defining characteristic of the Alpha design team as its sense of a shared culture. The design processes are encoded, more often than not, in a set of rituals rather than a set of documents. The process is passed on from the more experienced engineers to those at the start of their careers. This cultural memory is embodied in the group as a whole.