Memory Partitioning in AUTOSAR Compliant Functional Safety Projects

In automotive systems that include one or more electrical and/or electronic (E/E) systems, it’s imperative that utmost care is given to the functional behavior at all times so as to reduce the probability of their malfunctioning. As there is a probability that the deviation can result in harm, adherence to ISO-26262 is mandatory. One such important safety requirement is Freedom From Interference(FFI). FFI for memory (mainly volatile memory- RAM) is under focus here. The intention is to prevent corruption/unintended modification of safety critical data (ASIL- A,B,C or D) by QM components. In automotive domain, the increasing complexity of modern vehicles and especially their E/E systems has made strides towards AUTOSAR projects, making them prevalent. This paper presents a method to partition RAM memory in such AUTOSAR projects, by activating the Memory Protection Unit(MPU) using the AUTOSAR configuration tool. The partitioned software can thus help achieve FFI, adhering to Functional Safety. This paper also has pointers on exception debugging, to know the root cause of an unintended execution path which can further help in improving the quality and functionality.