A problem exists in the 10 Gigabit Ethernet MAC v4.0 core. It occurs if the following sequence of data is presented at the XGMII interface:
- Full column of Idle ||I||
- Start code /S/ in Lane 0
- Corruption of one or more of the 6 preamble bytes (0x55)
- Corruption or absence of the SFD (0xD5) in Lane 3 of the XGMII column following /S/
This frame will be correctly ignored by the MAC. However, the problem is that the following frame will have "rx_bad_frame" asserted, regardless of its validity.
This will be fixed in v5.0 release of the core.