A method of fault diagnosis of analog parts of electronic embedded systems with tolerances

Abstract

A new method of fault detection and localization of analog parts with tolerances of non-faulty elements in embedded mixed-signal systems controlled by microcontrollers are presented. The method consists of three stages. In the pre-testing stage, a fault dictionary is created. The measurement stage bases on the measurements of duration times of output signals of analog comparators realized by internal resources of the microcontroller. The time response to a stimulating square impulse of the analog part is applied to the inputs of the comparators with different threshold voltages. In the last stage, the fault detection and localization are performed by the microcontroller. The main advantage and novelty of the method is the fact that the BIST consists only of analog comparators and internal resources of the microcontroller already mounted in the system. Hence, this approach simplifies the structure and design of BISTs, which allows to decrease test costs. The results of the experimental verification of the method are included in this paper.