Conception testable de circuits intégrés complexes à très haut niveau

Abstract

The objective of this work is to propose a new online testing approach for embedded sys tems which are dedicated to critical applications. This online testing approach is based on a BIST (Built-In Self-Test) approach in which optical sensors are added to the classi cal architecture BILBO (Built-In Logic-Block Observation). Thus, a new Optical BILBO registers (OBILBO) are proposed. The complete test method developed in this thesis, adapted to the hardware duplication technique, ensures a functional checking of the sys tem during its normal operating in order to detect the presence of possible errors without interrupting or slowing down its normal functioning. Besides, it allows immediate detec tion of simple stuck at faults with error latency of only one clock cycle without having recourse to any operation of test vectors generation. In addition, this approach also allows to perform tests in offline mode by diagnosing faults that may appear on the OBILBO registers themselves. The advantage of this approach is to reduce the number of the N shifting operations (N: number of the OBILBO register stages) necessary to perform such a scan to a single shifting operation and thus to avoid the serial nature of this register. In addition to this possibility, the OBILBO register equally produces an optical signature that can be analyzed at remote system. The VHDL-AMS tool is used to model, simulate and validate the technique presented in this manuscript.