CHAPTER 24 SAFETY FUNCTIONS
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CHAPTER 24 SAFETY FUNCTIONS
24.1
Overview of Safety Functions
The following safety functions are provided in the RL78/G1H 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/G1H 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.
(2) RAM parity error detection function
This detects parity errors when the RAM is read as 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 uses the timer array unit to perform a self-check of the CPU/peripheral hardware clock frequency.
(7) A/D test function
This is used to perform a self-check of A/D converter by performing A/D conversion on the positive internal
reference voltage, negative reference voltage, analog input channel (ANI).
(8) Digital output signal level detection function for I/O pins
When the I/O pins are output mode, the output level of the pin can be read.
Remark
Refer to the IEC60730/60335 self-test library application notes (R01AN1062, R01AN1296) for the
RL78 MCU Series, for more information on usage examples of the safety functions required to
comply with the IEC60730 and IEC61508 safety standards.
Summary of Contents for RL78/G1H
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