upd70f3402 Renesas Electronics Corporation., upd70f3402 Datasheet - Page 795

• Manufacturer Part Number: upd70f3402
• Description: 32-/16-bit Single-chip Microcontroller With Can Interface
• Manufacturer: Renesas Electronics Corporation.

26.4 Operation
An example of the CRC operation circuit is shown below.
The code when 01H is sent LSB first is (1000 0000). Therefore, the CRC code from generation polyno-
mial X
0001) using the modulo-2 operation formula.
The modulo-2 operation is performed based on the following formula.
Therefore, the CRC code becomes
Since LSB first is used, this corresponds to 1189H in hexadecimal notation.
0 + 0 = 0
0 + 1 = 1
1 + 0 = 1
1 + 1 = 0
16
− 1 = 1
+ X
12
+ X
Figure 26-4: CRC Operation Circuit Operation Example (LSB First)
(1) Setting of CRCIN = 01H
(2) CRCD register read
5
+ 1 becomes the remainder when (1000 0000) X
1 0001 0000 0010 0001 1000 0000 0000 0000 0000 0000
User’s Manual U16702EE3V2UD00
Chapter 26 CRC Function
LSB
1001
9
1000 1000 0001 0000 1
0001 1000 1000
8
b15
LSB
1000 0001 0000 1000 0
1000 1000 0001 0000 1
1
1001 0001 1000 1000
1
1189H
1000 1000
b7
16
CRC code is stored
is divided by (1 0001 0000 0010
MSB
MSB
b0
b0
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