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Receive and Transmit Description
46 Software Developer’s Manual
3.3.6.2 TCP/UDP Offload Transmit Descriptor Status Field
Four bits are reserved to provide transmit status, although only one is currently assigned for this
specific descriptor type. The status word is only written back to host memory in cases where the RS
is set in the command.
Table 3-16. Transmit Status Layout
3.3.7 TCP/IP Data Descriptor Format
The TCP/IP data descriptor is the companion to the TCP/IP context transmit descriptor described
in the previous section. This descriptor type provides similar functionality to the legacy mode
descriptor but also integrates the checksum offloading and TCP Segmentation feature.
To select this descriptor format, bit 29 in the command field (TDESC.DEXT) must be set to 1b and
TDESC.DTYP must be set to 0001b. In this case, the descriptor format is defined as shown in
Table 3-17.
32 1 0
RSV DD
TDESC.STA Description
RSV
Reserved
Reserved for future use. Reads as 0b.
DD (bit 0)
Descriptor Done
Indicates that the descriptor is finished and is written back after the descriptor has
been processed.