Visible to Intel only — GUID: nik1411172619156
Ixiasoft
Visible to Intel only — GUID: nik1411172619156
Ixiasoft
3.2.3.2. 40-100GbE IP Core Preamble Processing
The preamble sequence is Start, six preamble bytes, and SFD. If this sequence is incorrect the frame is ignored. The Start byte must be on receive lane 0 (most significant byte). The IP core uses the SFD byte (0xD5) to identify the last byte of the preamble. The MAC RX looks for the Start, six preamble bytes and SFD.
By default, the MAC RX removes all Start, SFD, preamble, and IPG bytes from accepted frames. However, if you turn on the RX preamble pass-through feature, by setting bit 0 of the Preamble Pass-Through Configuration register at offset 0x125 , the MAC RX does not remove the eight-byte preamble sequence.