Introduction to the CRISP Instruction Set Architecture

Since 1975 the Bell Labs C Machine Project has designed several computer architectures to support the C programming language1 efficiently. These designs have evolved into the current C Machine instruction set architecture. The CRISP Microprocessor is one particular implementation of that architecture. Since we wish to describe the capabilities of a particular implementation in this paper, we will use "CRISP" in describing both the architecture and the implementation. While C Machines are designed to execute the C programming language particularly well, this by no means excludes the efficient execution of other languages.2