5.1.1 Background Information

The IEC 60730 standard encompasses all aspects of appliance design. Annex H of the standard covers the aspects most relevant to microcontrollers. It details the tests and diagnostics which are intended to ensure safe operation of embedded control hardware and software. IEC 60730 defines three classifications for electronic control functions:

• Class A - Control functions which are not intended to be relied upon for safety of the equipment
• Class B - Control functions intended to prevent unsafe operation of the controlled equipment
• Class C - Control functions intended to prevent special hazards such as explosions

Specific design techniques have been used in the SAM9X7 to ease compliance with the IEC 60730 Class B Certification and to resolve general-purpose safety concerns. This allows reduced software development and code size as well as savings on external hardware circuitry, since built-in self-tests are already embedded in the MPU. Table 5-1 gives the list of peripherals which incorporate these techniques, and details whether these features are applicable for the IEC 60730 Class B Certification or for general-purpose safety considerations.