SPRUJ17I March 2022 – August 2025 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The 4-byte checksum encapsulation word is included as the last 4-bytes of the transmit packet data when EOP buffer descriptor CHKSUM_ENCAP is set. The PACKET_LENGTH includes the four encapsulation bytes.
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 |
| RESERVED | IPV4_VALID | IPV6_VALID | TCP_UDP_N | FRAGMENT | CHKSUM_ERROR | ||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| CHECKSUM_ADD | |||||||||||||||
| Bit | Field | Description |
|---|---|---|
| 31-21 | RESERVED | Reserved |
| 20 | IPV4_VALID | An IPV4 TCP or UDP packet was detected |
| 19 | IPV6_VALID | An IPV6 TCP or UDP Packet was detected |
| 18 | TCP_UDP_N |
TCP or UDP packet - Valid only when either the IPV4_VALID or IPV6_VALID bits are set 0h - Indicates UDP packet was detected 1h - Indicates TCP packet was detected |
| 17 | FRAGMENT | Indicates that an IP fragment was detected. Valid only when either the IPV4_VALID or IPV6_VALID bits are set. |
| 16 | CHKSUM_ERROR | Checksum Error detected. Valid only when either the IPV4_VALID or IPV6_VALID bits are set. |
| 15-0 | CHECKSUM_ADD | Checksum Add Value - this is the value that was summed during the checksum computation. This value is 0xFFFF for IPV4/6 UDP/TCP packets with no checksum error. |