LAN9218I_12 Datasheet, PDF (49/134 Pages) SMSC Corporation – High-Performance Single-Chip 10/100 Ethernet Controller with HP Auto-MDIX and Industrial Temperature Support

High-Performance Single-Chip 10/100 Ethernet Controller with HP Auto-MDIX and Industrial Temperature Support
Datasheet
Figure 3.13, "TX Example 1" illustrates the TX command structure for this example, and also shows
how data is passed to the TX data FIFO.
Data Written to the
Ethernet Controller
31
0
TX Com m and 'A'
Buffer End Alignment = 1
TXCommand'A'
Data Start Offset = 7
First Segment = 1
TXCommand'B'
Last Segment = 0
Buffer Size = 79
7-Byte Data Start Offset
TX Com m and 'B'
Packet Length = 111
Data Passed to the
TX Data FIFO
TXCommand'A'
TXCommand'B'
79-BytePayload
Pad DWORD 1
10-Byte
EndPadding
31
TX Com m and 'A'
Buffer End Alignment = 1
Data Start Offset = 0
First Segment = 0
Last Segment = 0
Buffer Size = 15
TX Com m and 'B'
Packet Length = 111
0
TXCommand'A'
TXCommand'B'
15-BytePayload
1B
31
0
TX Com m and 'A'
Buffer End Alignment = 1
10-Byte
EnTXdOCoffmsemtPaanddd'iAn'g
Data Start Offset = 10
TXCommand'B'
First Segment = 0
Last Segment = 1
10-Byte
Buffer Size = 17
Data Start Offset
TX Com m and 'B'
Packet Length = 111
17-BytePayloadData
79-BytePayload
TXCommand'A'
15-BytePayload
TXCommand'A'
17-BytePayload
NOTE: Extra bytes
betw een buffers are
not transmitted
5-ByteEndPadding
Figure 3.13 TX Example 1
SMSC LAN9218i
49
DATASHEET
Revision 2.9 (03-01-12)