RL78/G1H CHAPTER 24 SAFETY FUNCTIONS
R01UH0575EJ0120 Rev. 1.20 Page 776 of 920
Dec 22, 2016
24.2Registers Used by Safety Functions
The safety functions use the following registers:
The content of each register is described in 24.3 Operation of Safety Functions.
24.3 Operation of Safety Functions
24.3.1 Flash memory CRC operation function (high-speed CRC)
The IEC60730 standard mandates the checking of data in the flash memory, and recommends using CRC to do
it. The high-speed CRC provided in the RL78/G1H can be used to check the entire code flash memory area
during the initialization routine. The high-speed CRC can be executed only when the program is allocated on the
RAM and in the HALT mode of the main system clock.
The high-speed CRC performs an operation by reading 32-bit data per clock from the flash memory while
stopping the CPU. This function therefore can finish a check in a shorter time.
The CRC generator polynomial used complies with “X
16
+ X
12
+ X
5
+ 1” of CRC-16-CCITT.
The high-speed CRC operates in MSB first order from bit 31 to bit 0.
Caution The CRC operation result might differ during on-chip debugging because the monitor
program is allocated.
Remark The operation result is different between the high-speed CRC and the general CRC, because the
general CRC operates in LSB first order.
Register Each Function of Safety Function
• Flash memory CRC control register (CRC0CTL)
• Flash memory CRC operation result register (PGCRCL)
Flash memory CRC operation function (high-speed CRC)
• CRC input register (CRCIN)
• CRC data register (CRCD)
CRC operation function (general-purpose CRC)
• RAM parity error control register (RPECTL) RAM parity error detection function
• Invalid memory access detection control register (IAWCTL) RAM guard function
SFR guard function
Invalid memory access detection function
• Timer input select register 0 (TIS0) Frequency detection function
• A/D test register (ADTES) A/D test function
• Port mode select register (PMS) Digital output signal level detection function for I/O pins
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