Cmsemicon CMS80F731 Series, Reference Manual

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CMS80F731x Reference Manual
15.
Cyclic Redundancy Check Unit (CRC)
15.1 Overview
In order to ensure safety during operation, the IEC61508 standard requires that data be confirmed even during CPU
operation. This universal CRC module performs CRC operations as a peripheral function during CPU operation. The universal
CRC module performs CRC checks by specifying the data to be confirmed by the program, and is not limited to the code flash
memory area but can be used for multi-purpose checks.
The CRC generation polynomial uses CRC16-CCITT's "X 16 + X12 +X 5 +1".
15.2 Related Registers
15.2.1
CRC Data Input Register CRCHIN
F708H
Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
CRCIN
CRCIN7 CRCIN6 CRCIN5 CRCIN4 CRCIN3 CRCIN2 CRCIN1 CRCIN0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Reset value 0 0 0 0 0 0 0 0
Bit7~Bit0 CRCIN<7:0> Enter the 8-bit data that requires CRC transport.
15.2.2
The CRC Operation Results in a Low 8-bit Data Register, CRCDL
F709H
Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
CRCDL
CRCD7 CRCD6 CRCD5 CRCD4 CRCD3 CRCD2 CRCD1 CRCD0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Reset value 0 0 0 0 0 0 0 0
Bit7~Bit0 CRCD<7:0> The CRC operation results in 8 bits lower data
15.2.3
The CRC Operation Results in a High 8-bit Data Register With CRCDH
F70AH
Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
CRCDH
CRCD15 CRCD14 CRCD13 CRCD12 CRCD11 CRCD10 CRCD9 CRCD8
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Reset value 0 0 0 0 0 0 0 0
Bit7~Bit0 CRCD<15:8> The CRC operation results in 8 bits higher data