30.3.10.7 CRC Examples

The following table provides CRC configuration with a polynomial size of 32. For each term (xn) of the polynomial, a corresponding bit in CRCPOLY is set to ‘1’. This polynomial implements CRC-32-IEEE 802.3.

Table 30-20. Example 32-Bit Polynomial CRC Setup
Field Name Bit Value Description
CRCCTRL.PLEN 1 32-bit polynomial length
CRCPOLY 
0000   0100 1100 0001
   0001 1101 1011 011-
 CRC polynomial:

x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x +1

The following table provides CRC configuration with the polynomial size of 16. The value of CRCPOLY shows the 12th bit and the 5th bit set to ‘1’, as required by the equation. The 0th bit required by the equation is always XOR-ed.

Table 30-21. Example 16-Bit Polynomial CRC Setup
Field Name Bit Value Description
CRCCTRL.PLEN 0 16-bit polynomial length
CRCPOLY 
0000   0000 0000 0000
   0001 0000 0010 000-
 CRC polynomial:

x16 + x12 + x5 + 1