Usage Notes; Module Stop Function Setting; Note On Transmission - Renesas RX100 Series User Manual

RX13T Group
25.4

Usage Notes

25.4.1

Module Stop Function Setting

Operation of the CRC calculator can be disabled or enabled using the module stop control register B (MSTPCRB). After
a reset, the CRC is in the module stop state. Register access is enabled by releasing the module stop state. For details,
refer to section 11, Low Power Consumption .
25.4.2

Note on Transmission

Note that the sequence of transmission for the CRC code differs according to whether transmission is LSB first or MSB
first.
When transmitting 32-bit data
1. CRC code
After specifying the method for generation calculation, write data to CRCDIR register in the order of (1), (2), (3), and (4).
CRCDIR
CRCDIR
CRCDIR
CRCDIR
CRCDOR
2. Transmit data
(i) When transmission is LSB first
(ii) When transmission is MSB first
Output
Figure 25.6 LSB First and MSB First Data Transmission
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
7
(1)
7
(2)
7
(3)
7
(4)
CRC code generation
15
CRC code (H)
CRC code
7 0 7 0 7
(H) (L)
7 0 7 0 7
(1) (2)
0
0
0
0
8 7
CRC code (L)
0 7 0 7
(4) (3) (2)
0 7 0 7
(3) (4) (H)
25. CRC Calculator (CRC)
0
0 7 0
(1)
Output
CRC code
0 7 0
(L)
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