Renesas RL78 Series User Manual page 761

RL78/G1D
23.3.2.2 CRC data register (CRCD)
This register is used to store the CRC operation result of the general-purpose CRC.
The setting range is 0000H to FFFFH.
After 1 clock of CPU/peripheral hardware clock (f
operation result is stored to the CRCD register.
The CRCD register can be set by a 16-bit memory manipulation instruction.
Reset signal generation clears this register to 0000H.
Address: F02FAH After reset: 0000H
Symbol 15 14
CRCD
Cautions 1. Read the value written to CRCD register before writing to CRCIN register.
2. If conflict between writing and storing operation result to CRCD register occurs, the writing is
ignored.
<Operation flow>
R01UH0515EJ0120 Rev.1.20
Dec 16, 2016
Figure 23-5. Format of CRC Data Register (CRCD)
R/W
13 12 11 10
Figure 23-6. CRC Operation Function (General-Purpose CRC)
START
Specify the start and end addresses
Write CRCD register to 0000H
Read data
Store data to CRCIN register
Address+1
Last address?
No
CHAPTER 23 SAFETY FUNCTIONS
) has elapsed from the time CRCIN register is written, the CRC
CLK
9 8 7 6
Store the start and end addresses in a general-
;
; purpose register.
; Initialize CRCD register
; Read 8-bit data of corresponding address
; Execute CRC calculation for 8-bit data
Yes
1 clock wait (f
Read CRCD register
5 4 3 2
)
CLK
; Get CRC result
; Compare the value
; with the stored
End
; expected value and
; make sure that the
; values match.
1 0
740