Manufacturers of household appliances must take steps to ensure safe and reliable operation of their products in order to meet the IEC 60730 standard. Annex H of this standard covers the aspects most relevant to microcontrollers including the three software classifications defined for automatic electronic controls. Most home appliances including washing machines, dryers, refrigerators, freezers, and cookers/stoves fall into the Class B classification. Luminary Micro provides an IEC 60730 Class B Test Library to support its customers in the Class B certification process.

Current and future Stellaris microcontrollers are designed specifically for safety-critical industrial and consumer applications, offering integrated features such as high-reliability automotive-grade flash memory, up to two watchdog timers that take advantage of the non-maskable interrupt (NMI) handler safety feature of the ARM Cortex-M3 processor, and deterministic, fast interrupt processing through the nested vectored interrupt controller (NVIC). Some Stellaris family members also offer an integrated precision oscillator to supply an independent time base when periodic safety tests are executed. In addition, select Stellaris microcontrollers include ROM preloaded with a cyclic redundancy check (CRC) function, which is especially useful in verifying the contents of the Stellaris microcontroller’s memory.

The advanced motion control of Stellaris microcontrollers also integrates important safety features, such as fault conditioning for each of the four motion-control PWM output pairs in order to provide quick motor shutdown in low latency situations and quadrature encoder inputs for precise closed-loop control. From an analog standpoint, Stellaris microcontrollers feature analog comparators to trigger Stellaris’ accurate analog-to-digital converter and to trigger an interrupt when needed, which is useful for infrequent out-of-range events such as a current or voltage spike. This Stellaris capability eliminates the performance-wasting requirement of constant CPU polling. In addition, Stellaris microcontrollers feature an internal temperature sensor, which can be used to monitor and shut down an appliance if the appliance overheats. Finally, the Stellaris family offers highly synchronized connectivity features for precision internetworking, such as a fully integrated 10/100 Ethernet MAC/PHY augmented with hardware assisted IEEE 1588 Precision Time Protocol (PTP) capability, and up to three integrated Controller Area Network (CAN) 2.0 MACs. These features, along with the vast other features of the Stellaris family, favorably positions the microcontrollers into cost-conscious applications requiring significant control processing, connectivity, and safety capabilities, such as cooking products, washing/drying machines, dishwashers, refrigerators and freezers, HVAC controls, motor controls, vacuum cleaners, building access, lifts and elevators, medical instrumentation, and gaming devices.