On the in-field testing of spare modules in automotive microprocessors

Currently, the most of the available strategies devised for in-field testing of microprocessor cores in the automotive market, are mainly oriented to test the more representative functional modules. However, most of the modern architectures also include a series of spare computational components that perform very specific functionalities. For example, merging modules, masked and reverse operation modules, circular buffers, and special counters able to speed up the final application. In this paper, we provide a set of guidelines for the generation of Software-Based Self-Test programs that can be used to functionally test these modules during the in-field operation of the processor core. For every one of these modules, ad-hoc techniques are illustrated. The experimental results were gathered on two different multi-core designs manufactured by STMicroelectronics.