Use of a Macro Processor in Logical Design

This note describes a technique of logical design using a standard machine-language assembler as the basic tool. An analogy is drawn between the assembly of logic modules by an engineer and the compiling of instructions by a programmer. This analogy can be used to enable an assembler to generate directly, a wiring list, as well as computing such design parameters as the cost, and the power and space requirements of the design. The designer works in a macro language, where a macro may stand for a logic module or a self- contained logic circuit within a module. This language contains the essential logical design information divorced from irrelevant trivia such as the allocation of logical functions to modules and the arrangement of modules in a mounting panel. Thus, optimization of the wiring layout can be conveniently carried out after the logical design is complete. The expression of the design in macro form also allows checkout of the logic by simulation.