Hyundai N700E-055HF, Instruction Manual

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N700E INSTRUCTION MANUAL
9-6
16bit CRC generation
The step of CRC generation is as follows:
1. All of 16-bit register is 1.0xffff
2. The exclusive OR of 16-bit register and 8-bit register.
3. Shift right side 1bit 16-bit register
4. If the result of step 3 is 1, exclusive OR 16-bit register and 0xa001.
5. Execute 8 times step 3 and step 4.
6. Execute step 2
∼
6 until data completion.
7. Exchange the step 6 result of higher 8bit and lower 8bit.
Ex)The case of D01 output frequency reading.
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
Communication
Number
Command Parameter Parameter number
0x01 0x03 0x01 0x01 0x00 0x01
The sequence of addition Byte(01x01)
16-BIT REGISTER MSB Flag
(Exclusive OR) 1111 1111 1111 1111
01 0000 0001
1111 1111 1111 1110
Shift 1 0111 1111 1111 1111
Shift 2 0011 1111 1111 1111 1
Polynomial 1010 0000 0000 0001
1001 1111 1111 1110
Shift 3 0100 1111 1111 1111
Shift 4 0010 0111 1111 1111 1
Polynomial 1010 0000 0000 0001
1000 0111 1111 1110
Shift 5 0100 0011 1111 1111
Shift 6 0010 0001 1111 1111 1
Polynomial 1010 0000 0000 0001
1000 0001 1111 1110
Shift 7 0100 0000 1111 1111
Shift 8 0010 0000 0111 1111 1
Polynomial 1010 0000 0000 0001
1000 0000 0111 1110
Byte 1~6 CRC of operation results
0x01
0x03
0x01
0x01
0x00
0x01 0x807e
0x3364
0x30e1
0x8831
0xd449
0x36d4
Change upper and lower 8 bit of result 0x36d4 : 0xd436
Byte7 : Upper 8 bit of CRC = 0xd4
Byte8 : Lower 8 bit of CRC = 0x36