Renesas M16C/64C User Manual page 688

M16C/64C Group
When using CRC-CCITT with LSB first:
Generator polynomial: X
Setting procedures
(1) Write 0000h (initial value) to the CRCD register.
(2) Write 01h to the CRCIN register.
(3) Write 23h to the CRCIN register.
Figure 29.2 CRC Calculation When Using CRC-CCITT
When using CRC-16 with MSB first
Generator polynomial: X
Setting procedures
(1) Write 0000h (initial value) to the CRCD register.
CRCD register
(2) Write 80h to the CRCIN register.
CRCIN register
CRCD register
(3) Write C4h to the CRCIN register.
CRCIN register
CRCD register
Figure 29.3 CRC Calculation When Using CRC-16
R01UH0092EJ0110 Rev.1.10
Jul 31, 2012
16 12
+ X + X
b15
CRCD register
CRCIN register
b15
CRCD register
CRCIN register
b15
CRCD register
16 15 2
+ X +X + 1 (1 1000 0000 0000 0101b)
b15
b15
b15
5
+ 1 (1 0001 0000 0010 0001b)
b0
0000h
b7 b0
01h
b0
1189h
b7 b0
23h
b0
0A41h
b0
0000h
b7 b0
80h
After two cycles, the result is stored
in the CRCD register.
b0
8303h
b7 b0
C4h
After two cycles, the result is stored
in the CRCD register.
b0
0292h
29. CRC Calculator
After two cycles, the result is stored
in the CRCD register.
After two cycles, the result is stored
in the CRCD register.
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