Free Self-Test Software for STM32 MCU

STMicroelectronics announced a software library for the STM32 Flash microcontroller family - which is based on the ARM CortexT-M3 core. The software was designed specifically to simplify the testing and securing end-product approval and compliance with the demands of the IEC 60335-1 standard, when the MCU is used in household appliances. Since October 2007, IEC 60335-1 requires the software of MCU-based appliances to be evaluated according to its impact on overall consumer and application safety. When some of the fault detection relies on the microcontroller, the embedded code must contain self-test routines, and must be evaluated under the so-called Class B requirements for its ability to detect safety critical failures.

 The self-diagnostic software modules developed by ST for the STM32 family have been approved by the VDE (German Association for Electrical, Electronic & Information Technologies) testing and certification institute, which is recognized globally for its efforts. Now, when a manufacturer uses these modules in an application - unchanged and in accordance with ST's integration guidelines - the application will not need to be completely re-evaluated by VDE as part of the final product certification, thereby saving significant time for the appliance manufacturer. The software library, with associated documentation, is available free of charge. It includes a complete safe-boot sequence, plus self-diagnostic modules for the CPU, non-volatile memory, RAM, and the clock frequency. Transparent RAM tests are also carried out during run-time. In addition, the STM32 embeds safety-related hardware, including dual internal watchdogs and fail-safe clock circuitry, which simplifies certification by reducing the number of self-test routines actually required and decreasing the software overhead.