LAN9118 Family Programmer Reference Guide
SMSC AN 12.12 33 Revision 1.0 (12-14-09)
APPLICATION NOTE
6.5.1 Transmit Command Words for Figure 6.1, "Multiple (3) Buffer Data Single Packet Transfer Sequence"

Note: The use of the First Segment and Last Segment flags in the example detailing the head,

middle, and tail of the chained transfer. Also see how the Buffer Size is unique for each

transfer, while the Packet Length reflects the total packet size. Finally, the Packet Tag must

be identical for correct operation. The new sequence of 3 data transfers looks like this:

Table6.6 TX_C MD_A for Segment 1

3
1
3
0
2
9
2
8
2
7
2
6
BUFFER
END
ALIGNME
NT
2
3
2
2
2
1
DATA
START
OFFSET
1
5
1
4
FIRST
SEGMENT
LAST
SEGME
NT
1
1
BUFFER
SIZE

0x0 0x3 1 0 0x1d

Table6.7 TX_C MD_B for Segment 1

PACKET TAG 15 14 13 12 11

PACKET

LENGTH
0x5678 0x4e

Table6.8 TX_C MD_A for Segment 2

3
1
3
0
2
9
2
8
2
7
2
6
BUFFER
END
ALIGNMENT
2
3
2
2
2
1
DATA
START
OFFSET
1
5
1
4
FIRST
SEGMENT
LAST
SEGMENT
1
1 BUFFER SIZE
0x0 0x0 0 0 0x20

Table6.9 TX_CMD_B for Segment 2

PACKET TAG 15 14 13 12 11

PACKET

LENGTH
0x5678 0x4e

Table6.10 TX_CMD_A for Segment 3

3
1
3
0
2
9
2
8
2
7
2
6
BUFFER
END
ALIGNMENT
2
3
2
2
2
1
DATA
START
OFFSET
1
5
1
4
FIRST
SEGMENT
LAST
SEGMENT
1
1 BUFFER SIZE
0x0 0x0 0 1 0x11

Table6.11 TX_CMD_B for Segment 3

PACKET TAG 15 14 13 12 11

PACKET

LENGTH
0x5678 0x4e