Software-Based Self-Test Techniques for Dual-Issue Embedded Processors

Nowadays, Self-Test strategies for testing embedded processors are increasingly diffused, especially for safety critical systems. Test programs can be effectively used for this purpose. This paper describes a set of systematic self-test techniques for in-order dual-issue embedded processors. The paper shows how to produce test programs suitable for the detection of faults in five classes of sub-modules: duplicated computational modules; multi-port register file; duplicated pipeline registers and feed-forward paths; pipeline interlocking logic; and pre-fetch buffer. While some techniques extend single-issue test programs, new techniques are also shown; results are illustrated for a couple of 32-bit in-order dual-issue processors included in automotive Systems-on-Chip manufactured by STMicroelectronics.