Computer-assisted design of PROM-controlled state-machine circuits for logical applications

In the design of applications such as weather satellite receiving stations the digital circuits are sequential in operation and so lend themselves to a stored-program approach to allow easy functional changes. However, in many cases a conventional microprocessor cannot be used because of speed requirements. This type of circuit can best be implemented using a PROM-controlled state-machine processor with a low-level instruction set optimised for the particular application. A modular building block approach to such circuits and a corresponding development system for writing and testing programs is presented in this paper.