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AR# 14287

CORE Generator Gigabit Ethernet MAC - The receiver byte count is 4 bytes higher than expected when I calculate my own CRC


General Description: 

When I supply the CRC value, the GMAC (Gigabit Ethernet MAC) Receiver v1.0 and v2.0 byte count appears to be 4 bytes more than the actual number of bytes passed in the frame.


What appears to be an invalid byte count is actually correct -- the extra 4 bytes correspond to the CRC bytes that you supplied. 


This is consistent with the required behavior defined in the EtherStats document RFC2819 and should not change with the setting of a client-supplied CRC bit.

AR# 14287
Date Created 08/29/2007
Last Updated 05/14/2014
Status Archive
Type General Article