Integrated circuits are at the root of all modern safety systems. Integrated circuits supply the logic, either control the sensors or to a growing extent are the sensors. Integrated circuits(IC) drive the final elements to achieve a safe state. Integrated circuits are the platform on which the software runs. The level of integration possible within semiconductors can simplify the system level implementation at the cost of the added complexity within the IC itself. The level of integration gives improvements in system reliability due to parts count reduction, offers opportunities for increased diagnostic coverage with lower diagnostic test intervals and all at a cost that makes safety achievable. It could argued that this level of integration is a bad thing because of the added complexity. However at the price of complexity in the integrated circuits can come a major simplification at the module and system levels. Surprisingly while there are functional safety standards which address process control, machinery, elevators, variable speed drives and toxic gas sensor there is no functional safety standard dedicated to integrated circuits. This paper gives guidance on interpreting the existing functional safety standards for semiconductors.
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