A systems approach to microprocessor selection for a controller application

Includes bibliographical references (pages 158-162)This paper presents a systems approach to the proper selection of a microprocessor CPU (central processing unit). This selection process is addressed in the context of incorporating the microprocessor as the general purpose, stored program, digital computer element in a ground support equipment controller. Addressing the problem in this manner allows quantitative illustration of the methodology involved. However, the basic approach is applicable wherever it is desired to incorporate microprocessor technology into a controller design.\ud The approach taken in this paper consists of two phases, termed the functional capability review phase, and the cost effectiveness evaluation phase. The functional capability review phase addresses the important functions and features of the CPU integrated circuit, and the required support circuitry to enable it to function as a digital computer. Also discussed are the hardware/software development aids which are required and most often desired, to develop the microcomputer (CPU plus support circuitry) hardware and its associated software.\ud Having gained a detailed understanding of the functional capabilities and interrelationships of the CPU, support circuitry, and hardware/software development aids, the systems designer evaluates this capability in relation to the design problem requirements through a cost effectiveness evaluation. The cost effectiveness evaluation, developed using utility theory and sensitivity analysis, enhances the knowledge gained from the functional capability review by projecting the impacts of the capabilities into the probability of success of the system design.\ud This two-phase approach extends the system designer's decision making ability by allowing him to couple the technical intricacies of microprocessor technology with insights into the ultimate cost effectiveness resulting from the alternative courses of action available to him for implementing the microprocessor based design