Analog Devices ADuCM355 Hardware Reference Manual page 305

ADuCM355 Hardware Reference Manual
8-Bit Polynomial Programming for MSB First Calculation
Polynomial: CRC-8-ATM
8 2
x + x + x + 1 = (1) 0000 0111 = 0x07
where the largest exponent (x
When left justified in the polynomial register, the register format is detailed in Table 399.
Table 399. 8-Bit Polynomial Programming Register Format, MSB First Calculation
Register
CRC Polynomial Register (POLY)
CRC Result Register (Result)
Initial Seed Programmed in CRC Result Register (Result)
8-Bit Polynomial Programming for LSB First Calculation
Polynomial: CRC-8-ATM
8 2
x + x + x + 1 = 1000 0011 (1) = 0x83
where the smallest exponent (x
When right justified in the polynomial register, the register format is detailed in Table 400.
Table 400. 8-Bit Polynomial Programming Register Format, LSB First Calculation
Register
CRC Polynomial Register (POLY)
CRC Result Register (Result)
Initial Seed Programmed in CRC Result Register (Result)
The CRC engine uses the following 32-bit CRC polynomial as the default (as per the IEEE 802.3 standard):
32 26 23 22
g(x) = x + x + x + x
This value is programmed for MSB first calculation by default as shown in Table 401.
Table 401. Default CRC Polynomial Register (POLY) Value
Bit(s)
[31:24]
[23:16]
[15:8]
[7:0]
8
term) is implied. Therefore, the polynomial is 0000 0111.
0
term) is implied. Therefore, the polynomial is 1000 0011.
16 12 11 10 8
+ x + x + x + x + x + x
7 5 4 2
+ x + x + x + x + 1
Value
0x04
0xC1
0x1D
0xB7
Rev. B | Page 305 of 312
UG-1262
Bit(s) Value
[31:24] 0000 0111
[23:16] 0x08B0
[15:8] 0x08B0
[7:0] 0x08B0
[31:24] CRC result
[23:16] 0x08B0
[15:8] 0x08B0
[7:0] 0x08B0
[31:24] CRC seed
[23:16] 0x08B0
[15:8] 0x08B0
[7:0] 0x08B0
Bit(s) Value
[31:24] 0x08B0
[23:16] 0x08B0
[15:8] 0x08B0
[7:0] 1000 0011
[31:24] 0x08B0
[23:16] 0x08B0
[15:8] 0x08B0
[7:0] CRC result
[31:24] 0x08B0
[23:16] 0x08B0
[15:8] 0x08B0
[7:0] CRC seed