Effective software-based self-test strategies for on-line periodic testing of embedded processors

Software-based self-test (SBST) strategies are particularly useful for periodic testing of deeply embedded processors in low-cost embedded systems with respect to permanent and intermittent operational faults. Such strategies are well suited to embedded systems that do not require immediate detection of errors and cannot afford the well-known hardware, information, software, or time-redundancy mechanisms. We first identify the stringent characteristics of a SBST program to be suitable for on-line periodic testing. Also, we study the probability for a SBST program to detect permanent and intermittent faults during on-line periodic testing. Then, we introduce a new SBST methodology with a new classification and test-priority scheme for processor components. After that, we analyze the self-test routine code styles for the three more effective test pattern generation (TPG) strategies in order to select the most effective self-test routine for on-line periodic testing of a component under test. Finally, we demonstrate the effectiveness of the proposed SBST methodology for on-line periodic testing by presenting experimental results for two pipeline reduced instruction set computers reduced instruction set processors of different architecture.