Milton R. Grinberg
In digital design, the goal of a human expert is to translate a goal, such as "build a digital alarm clock," or "build a video display interface into a working digital circuit." This is a problem solving activitiy in which the expert’s general purpose problem solving abilities interact with his rich knowledge of the digital world. By translating the initial ideas through successively more refined "sketches," the human expert gradually arrives at a chip-level digital schematic that realizes the initial goals, and which may have bugs that will only be discovered after the circuit has been simulated or built and tested. The Semi-Automatic Digital Designer (SADD) is an experimental interactive knowledge-based design system, whose domain of expertise is digital electronics. The SADD project has two goals. First, I want to provide an intermediate digital design problem solver for which a human expert can interactively provide the high-level functional descriptions of a circuit, and which can take this high-level circuit description and refine it into a circuit schematic that performs the required task. Second, I am attempting to discover and express in a computer model that knowledge that makes the human designer an expert in digital design. This includes the generic information for each high-level digital function (e.g., counter, clock) and the methods needed to transform these functional descriptions into realizable circuits. As a first case study in design, I adopted a relatively sophisticated TV video display circuit called the Screensplitter. This is a real circuit of moderate overall complexity.