APPLYING TRACE THEORY TO DIGITAL DESIGN.

A digital system can be described in terms of its function and the signals it exchanges with its environment. Design by decomposition depends on the assumption that the environment of the module being designed is invariant and finishes when submodules can be defined entirely in primitive terms. In integrated circuit design, the stability of the environment is always in question unless modules are designed to be delay-insensitive. Trace theory offers a means of describing and composing modules and recovering their specifications from a design. The use of trace theory in design and simulation is illustrated by reviewing the design of a processor, and is shown to be a consistent method of specification at all levels of design.