Using the CRC Checker

When the CRC checker is used, it needs to be enabled, and the 64B/66B encoder and 64B/66B decoder should be bypassed.

• CRC_EN should be set to 1'b1.
• DATAPATH_CTRL can only be set to 3'b100 if the TX scrambler/RX descrambler is enabled, or 3'b111 if TX scrambler/RX descrambler is bypassed.

Another requirement is that depending on whether or not the RX 64B/66B descrambler is bypassed, the RX CRC checker must be set to the correct input endian format. The following must be set:

• When the RX 64B/66B descrambler is bypassed, INPUT_BYTE_ORDER must be set to 1'b0.
• When the RX 64B/66B descrambler is not bypassed, INPUT_BYTE_ORDER must be set to 1'b1.