BACKGROUND

Many automotive applications are required to be Automotive Safety Integrity Level D (ASIL D). ASIL D refers to International Organization for Standardization (ISO) 26262's highest classification of potential for severely life-threatening or fatal injury in the event of a malfunction, and includes the most stringent level of safety measures to apply for avoiding an unreasonable residual risk.

Analog data acquisition for an Engine Management System (EMS) and braking is ASIL D. Analog data acquisition is a process of measuring an analog data signal, and converting the analog data signal into digital data. For ASIL-D analog data acquisition, at least two homogeneous or heterogeneous Analog-to-Digital Converter (ADC) channels are used to detect random hardware faults. Conventionally, a Central Processing Unit (CPU), which is also ASIL-D, reads values of the different ADC channels, and performs a fault check. The fault check enables software to determine whether the analog data signal is captured without any faults in order to meet ASIL-D requirements. If the fault check indicates a fault, the CPU raises an alarm for reaction, such as by a Safety Management Unit (SMU). Complex System on Chips (SoCs) have more than 100 analog inputs to be measured. Even if only 10% of the signals need to be ASIL D, a fault check on the analog-to-digital conversion signals output from the different channels consumes a considerable amount of CPU bandwidth.

