Prevention and Detection Methods of Systematic Failures in the Implementation of SoC Safety Mechanisms not Covered by Regular Functional Tests

Hardware functional safety requirements are covered by verification and validation methods defined by ISO 26262 functional safety standard for automotive electronic systems. The implementation of most functional safety requirements for electronic devices can be covered by typical functional test methods at Register Transfer Level (RTL), complemented by formal proof to ensure that the RTL is equivalent to the netlist and to the physical implementation levels beyond. However, some implementation failures (systematic errors) cannot be detected using this method. This paper reports the cases faced during the development of a complex System-on-Chip for the automotive industry and discusses the verification and implementation checks that were performed to fill this gap.