Design of modular digital circuits for testability

Modular products and reconfigurable testing processes are crucial in modern manufacturing. This paper discusses the concept of product modularity, test modules of increased reusability and exchangeability, and some aspects of design for testability. A methodology for design of modular products for testability in the presence of testing modules is developed. An integrated approach to design of modular products and test processes is discussed. The relationship between product modularity and design for testability is explored. This paper focuses on digital circuits which may be difficult to decompose into modules. The impact of testability on module sizes is considered. The testability points are identified at the circuit level while modular testing is considered at the board and system level. The main contribution of this paper is in the development of a formal approach to modularize products, and to assess the impact of modularity on the design process and testability.