220.127.116.11. Preamble Processing
The IEEE standard specifies that frames must be separated by an interpacket gap (IPG) of at least 96 bit times. The MAC function, however, can accept frames with an IPG of less than 96 bit times; at least 8-bytes and 6-bytes in RGMII/GMII (1000 Mbps operation) and RGMII/MII (10/100 Mbps operation) respectively.
The MAC function removes the preamble and SFD fields from valid frames.