Functional Safety Solutions for Home Appliances (IEC/UL 60730)

Overview

The use of automated electronic control systems is expanding in recent years, and reliability and safety requirements are becoming important factors in system design. Due to the establishment of the IEC 60730 safety standard for household electronic equipment, home appliances also require automated electronic control design to guarantee safe and reliable operation.

Automated electronic control is also extremely important in the design of microcontroller-based control systems. There are three classes of software for automated electronic control.

Class A
Control functions that are not intended to be relied upon for the safety of the equipment
Examples: Room thermostats, humidity controllers, lighting controllers, timers, and switches
Class B
Control functions that are intended to prevent unsafe operation of the controlled equipment
Examples: Thermal cutoff and door locking for laundry machines
Class C
Control functions that are intended to prevent special hazards
Examples: Automatic burner control and thermal cutoff for sealed equipment

Solutions

Renesas offers application notes and sample code for supporting IEC 60730 Class B for the RL78 Family and the RX100/200/600 Series.
These application notes and sample code provide support for obtaining certification for your end product.

Diagnostics Required by IEC 60730 Class B and Support Status

IEC60730 Class B Requirements

  Standard Number and Section Location of MCU Diagnostics Error or Abnormality That Should be Inspected Supporting MCU Series
RL78 RX100/200/600
1.
CPU
1.1 Registers CPU Registers Stuck Support via software Support via software
1.3 Programme counter CPU Program Counter Stuck Support via IWDT Support via IWDT
2.
Interrupt handling and execution
  Interrupt unit No interrupt or too frequent interrupt Support via software Support via software
3.
Clock
  Clock Failure or Wrong frequency Support via TAU channel 0 or channel 5
Support via CAC
4.
Memory
4.1 Invariable memory ROM/Flash All single bit fault Support via general/high-speed CRC Support via general CRC
4.2 Variable memory RAM DC fault Support via software Support via software
6.
External Communication
6.1 Data Communication port Failure or not accurate Support via general CRC Support via general CRC
7.
Input/output periphery
7.1 Digital I/O Input/Output Port Stuck or not accurate Support via pin state read function when setting output Support via independent input register and output register
7.2 Analog I/O Analog Circuit Failure or not accurate Support via AD test function Support via AD test function

Location of Microcontroller Diagnostics Required by IEC 60730 Class B