RTL Test Justification and Propagation Analysis for Modular Designs.pdf

Journal of Electronic Testing, 9, 1–17 (1999) c 1999 Kluwer Academic Publishers, Boston. Manufactured in The Netherlands. RTL Test Justification and Propagation Analysis for Modular Designs ˘ YIORGOS MAKRIS AND ALEX ORAILOGLU Reliable Systems Synthesis Lab, CSE Department MC-0114, UCSD, La Jolla, CA 92093 makris@cs.ucsd.edu, alex@cs.ucsd.edu Received March 20, 1998; Revised June 25, 1998 Editor: N. Jha Abstract. Modular decomposition and functional abstraction are commonly employed to accommodate the growing size and complexity of modern designs. In the test domain, a divide conquer type of approach is utilized, wherein test is locally generated at each module’s boundary and consequently translated to global design test. We present an RTL analysis methodology that identifies the test justification and propagation bottlenecks, facilitating a judicious DFT insertion process. We introduce two mechanisms for capturing, without reasoning on the complete functional space, data and control module behavior related to test translation. A traversal algorithm that identifies the test translation bottlenecks in the design is described. The algorithm is capable of handling cyclic behavior, reconvergence and variable bit-widths in an efficient manner. We demonstrate our scheme on representative examples, unveiling its potential of accurately identifying and consequently minimizing the reported controllability and observability bottlenecks of large, modular designs. Keywor