Using a square-wave signal for fault diagnosis of analog parts of mixed-signal embedded systems controlled by microcontrollers

The paper presents a new method of single soft fault detection and localisation of analog parts in embedded mixed-signal electronic systems controlled by microcontrollers. The method consists of three stages: a pre-testing stage of a fault dictionary creation using identification curves, a measurement stage based on stimulating the tested circuit by a square-wave signal generated by the microcontroller and measurements of voltage samples of the circuit response by the internal ADC of the microcontroller. At a final stage the faults detection and localisation are performed by the microcontroller. The BIST consists only of internal devices of the microcontroller mounted in the system. Hence, this approach simplifies the structure of BISTs, which allows to reduce test costs.