Datasheet
RL78/L12 CHAPTER 23 SAFETY FUNCTIONS
R01UH0330EJ0200 Rev.2.00 776
Dec 13, 2013
CHAPTER 23 SAFETY FUNCTIONS
23.1 Overview of Safety Functions
The following safety functions are provided in the RL78/L12 to comply with the IEC60730 and IEC61508 safety
standards.
These functions enable the microcontroller to self-diagnose abnormalities and stop operating if an abnormality is
detected.
(1) Flash memory CRC operation function (high-speed CRC, general-purpose CRC)
This detects data errors in the flash memory by performing CRC operations.
Two CRC functions are provided in the RL78/L12 that can be used according to the application or purpose of use.
• High-speed CRC: The CPU can be stopped and a high-speed check executed on its entire code flash
memory area during the initialization routine.
• General CRC: This can be used for checking various data in addition to the code flash memory area while
the CPU is running.
Caution The high-speed CRC function cannot be used in products with an 8 KB code flash memory
(R5F10RB8, R5F10RF8, R5F10RG8, and R5F10RJ8).
(2) RAM parity error detection function
This detects parity errors when reading RAM data.
(3) RAM guard function
This prevents RAM data from being rewritten when the CPU freezes.
(4) SFR guard function
This prevents SFRs from being rewritten when the CPU freezes.
(5) Invalid memory access detection function
This detects illegal accesses to invalid memory areas (such as areas where no memory is allocated and areas to
which access is restricted).
(6) Frequency detection function
This function allows a self-check of the CPU/peripheral hardware clock frequencies using the timer array unit.
(7) A/D test function
This is used to perform a self-check of the A/D converter by performing A/D conversion of the A/D converter’s
positive and negative reference voltages, analog input channel (ANI), temperature sensor output voltage, and
internal reference voltage.
Remark For usage examples of the safety functions complying with the IEC60730 safety standards, refer to the
RL78 MCU series IEC60730/60335 self-test library application notes (R01AN1062 and R01AN1296).
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