Table: Invalid Segmented LBUS Cycles shows several invalid TX segmented LBUS cycles as indicated by the shading.
Cycle 3 is not valid because it contains two SOPs.
Cycle 5 does not contain an EOP even though there is an SOP in the next cycle.
Cycle 6 has an SOP even though the preceding packet was not closed with an EOP. This sequence is not permitted by the LBUS rules and results in undefined behavior.
Cycle 7 is idle even though tx_rdyout is asserted, and a packet transfer is already under way. This can result in buffer under-run. If this occurs, the Ethernet packet is not sent in its entirety without interruption, and a malfunction of the FCS calculation occurs.
Cycle 9 contains an idle segment during a packet transfer which is not permitted by the segmented LBUS rules.
Cycle 14 is not recommended because a data transfer is being performed even though tx_rdyout has been deasserted for the fifth consecutive cycle.
Cycle 15 must never be performed because tx_ovfout has been asserted. In the event of tx_ovfout being asserted, the 100G Ethernet IP core should be reset.