DA82562EM Intel, DA82562EM Datasheet - Page 170

• Manufacturer Part Number: DA82562EM
• Manufacturer: Intel

Specifications of DA82562EM

• Lead Free Status / Rohs Status: Not Compliant

82550 and 82551 Specific Information
B.3.4.3
162
Intermediate Frames Processing
The number of bytes left for transmission after the first frame is calculated by subtracting the N *
Maximum TCP Payload from the Total TCP/UDP Payload. In other words,
If the next frame is not the last frame, the number of bytes transmitted is updated and the frame
processing rules below should be followed.
•
•
•
•
TCP header is processed:
L2 header should be left intact as in the first frame.
IP header is processed:
TCP header is processed:
— Fragment offset equals 0. This is expected but not checked by hardware.
— IP options are not altered by hardware if they are present.
— IP header checksum is calculated by the checksum hardware if the IP checksum bit is set
— Sequence number is not changed.
— URG, RST, and SYN flags are expected to be clear but are not checked by hardware.
— ACK flag value will be transmitted as in the prototype header.
— Urgent pointer equals 0. This is expected but not checked by hardware.
— If the FIN flag equals 1, then it is cleared in the first frame.
— If the PSH flag equals 1, then it is cleared in the first frame.
— TCP options are not altered by hardware if they are present. TCP options include time
— TCP checksum is calculated by checksum hardware if the TCP checksum bit is set in the
— IP identification is incremented from last value.
— IP options are not altered by hardware if they are present.
— IP header checksum is calculated by checksum hardware if the IP checksum bit is set in
— Sequence number is updated for outgoing packets. The previous frame size (TCP payload
— All flags are left intact as in the first frame.
— Urgent pointer is left intact as in the first frame.
— TCP options are not altered by hardware if they are present
— Pseudo header checksum remains unchanged.
— TCP checksum is calculated by checksum hardware if the TCP checksum bit is set in the
in the IPCB.
stamp.
IPCB.
(N * MAX TCP PAYLOAD) – (TOTAL TCP/UDP PAYLOAD)
the IPCB.
only) is added to the previous frame sequence number (modulo 2
IPCB.
10/100 Mbps Ethernet Controller Family Open Source Software Developer Manual
32
).