Renesas H8S Family Hardware Manual page 550

Section 14 CRC Operation Circuit (CRC)
1. Serial reception (MSB first)
7
Input
1
2. Write H'87 to CRCCR
7
CRCCR 1 0 0
7
0 0 0
CRCDORH
CRCDORL
0 0 0
4. Write H'EF to CRCDIR
7
CRCDIR
1 1 1
7
0 0 0
CRCDORH
CRCDORL
0 0 0
6. Read from CRCDOR
CRC code = H'0000 → No error
Rev. 1.00 Mar. 12, 2008 Page 502 of 1178
REJ09B0403-0100
Data
0
0 0
1 1 1 0 0
F 0
0
0 0 1 1 1
CRCDOR clearing
0
0 0 0 0 0
0 0 0 0 0
0
0 1 1 1 1
CRC code generation
0
1 1 1 1 1
0 0 0 0 0
Figure 14.5 MSB-First Data Reception
7
1
1 1 1 0 1 1
E F
3. Write H'F0 to CRCDIR
7
CRCDIR 1 1
7
1 1
CRCDORH
CRCDORL
0 0
5. Write H'1F to CRCDIR
7
CRCDIR
0 0
7
0 0
CRCDORH
CRCDORL
0 0
CRC code
0
7
1 0 0 0 1 1
1
0
1 1 0 0 0
0
CRC code generation
0
1 0 1 1 1
1
0 1 1 1 1
1
0
0 1 1 1 1 1
CRC code generation
0
0 0 0 0 0
0
0 0 0 0 0
0
0
1
1 1
F