LAN9730 Datasheet, PDF (74/222 Pages) SMSC Corporation – High-Speed Inter-Chip (HSIC) USB 2.0

LAN9730/LAN9730i
Figure 4-16 illustrates the use of a pre-pended checksum preamble when transmitting an Ethernet frame consisting of
3 payload buffers.
FIGURE 4-16:
TX EXAMPLE ILLUSTRATING A PRE-PENDED TX CHECKSUM PREAMBLE
Note: The TX Checksum Preamble is
pre-pended to data to be transmitted.
FS is set in TX Command 'A' and CK is
set in TX Command 'B'. No start offset
may be added. FS must not be set for
subsequent fragments of the same
packet.
Data Written to the
Device
TX Command 'A'
TX Command 'B'
TX Checksum Preamble
TX Command 'A'
TX Command 'B'
Payload Fragment 1
Pad DWORD 1
TX Command 'A'
TX Command 'B'
Payload Fragment 2
EnTdX OC1fof0ms-eBmtyPatenaddd'Ain'g
TX Command 'B'
Payload Fragment 3
DS00001946A-page 74
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