82598EB Datasheet, PDF (227/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - Receive Functionality
IPCS, L4CS, UDPCS: Bit descriptions are listed in the following table:
Table 3-55. IPCS, L4CS, UDPCS
L4CS
0b
1b
1b
UDPCS
0b
0b
1b
IPCS
0b
1b/0b
1b/0b
Functionality
Hardware does not provide checksum offload. Special case: hardware does not
provide UDP checksum offload for IPv4 packet with UDP checksum = 0b.
Hardware provides IPv4 checksum offload if IPCS active and TCP checksum offload.
Pass/fail indication is provided in the Error field – IPE and TCPE. See PKTTYPE table
for supported packet types.
Hardware provides IPv4 checksum offload if IPCS is active along with UDP
checksum offload. Pass/fail indication is provided in the Error field – IPE and TCPE.
See PKTTYPE table for supported packet types.
See Section 3.5.2.12 for a description of supported packet types for receive checksum offloading. IPv6
packets do not have the IPCS bit set, but might have the L4CS bit set if the 82598 recognized the TCP
or UDP packet.
Extended Error Field
Extended Error (12)
• IPE (bit 11) – IPv4 checksum error
• TCPE (bit 10) – TCP/UDP checksum error
• USE (bit 9) – Undersize error – Undersized packet received
• OSE (bit 8) – Oversize error – Oversized packet received
• PE (bit 7) – Packet error – Illegal symbol or error symbol in the middle of a received packet
• Reserved (bit 6) – Reserved
• LE (bit 5) – Length error
• CE (bit 4) – CRC error
• HBO (bit 3) – Header buffer overflow (the header is bigger than the header buffer)
• Reserved (bits 2:0) – Reserved
RXE
Indicates that a data error occurred during the packet reception. A data error refers to the reception of
a /FE/ code from the XGMII interface which eventually causes CRC error detection (CE bit). This bit is
valid only when the EOP and DD bits are set and are not set in descriptors unless FCTRL.SBP (store-
bad-packets) is set. The RXE bit can also be set if a parity error was discovered in the packet buffer
while reading this packet. In this case, RXE can be set even if FCTRL.SBP is not set.
IPE
Indicates that the IPv4 header checksum is incorrect.
TCPE
Indicates that the TCP or UDP checksum is incorrect.
227