Functional testing and fault analysis based fault coverage enhancement techniques for embedded core based systems

The use of embedded cores poses several new problems in testing systems built around them. An important one amongst them is the need to achieve high fault coverage in an embedded context. Several impediments exist to obtaining a high fault coverage in such embedded systems. This paper presents a set of techniques for enhancing the fault coverage in and embedded DSP core based system. Its main contributions are: (i) It examines the various test constraints in such a system and the impediments to achieving a high fault coverage therein. (ii) It presents the development of functional testing techniques to enhance the coverage of the individual components. (iii) It complements this effort by presenting fault analysis techniques, to further enhance this coverage. The techniques described in the paper have been used to improve the fault coverage of devices built around Texas Instruments new DSP core, TMS320C27xx. Results indicate the effectiveness of functional testing and fault analysis techniques in raising the DSP core and memory wrapper logic coverage above 95%, over and above the best results obtained through ATPG.