SMSC LAN1198 Manual De Usuario
LAN9118 Family Programmer Reference Guide
Revision 1.0 (12-14-09)
32
SMSC AN 12.12
APPLICATION NOTE
Figure 6.1 Multiple (3) Buffer Data Single Packet Transfer Sequence
78-byte Payload Data
Data Transfers to the
LAN911x
Data Passed on to the TX
Data FIFO
31
0
31
0
31
0
TX Command A Word
TX Command B Word
TX Command B Word
3-byte Data Start
Offset
29-byte Payload Data
3-byte Data End
padding
32-byte Payload Data
17-byte Payload Data
TX Command A Word
TX Command A Word
TX Command B Word
TX Command B Word
TX Command B Word
TX Command ‘A’
Buffer End Alignment = 1
Data Start Offset = 3
First Segment = 1
Buffer End Alignment = 1
Data Start Offset = 3
First Segment = 1
Last Segment = 0
Buffer Size = 29
Buffer Size = 29
TX Command ‘B’
Packet Length = 78
Packet Length = 78
TX Command ‘A’
Buffer End Alignment = 1
Data Start Offset = 3
Buffer End Alignment = 1
Data Start Offset = 3
First Segment = 0
Last Segment = 0
Buffer Size = 32
Last Segment = 0
Buffer Size = 32
TX Command ‘B’
Packet Length = 78
Packet Length = 78
TX Command ‘A’
Buffer End Alignment = 1
Data Start Offset = 3
First Segment = 0
Last Segment = 1
Buffer Size = 17
Buffer End Alignment = 1
Data Start Offset = 3
First Segment = 0
Last Segment = 1
Buffer Size = 17
TX Command ‘B’
Packet Length = 78
Packet Length = 78
NOTE: Payload does not end on
DWORD boundary so 2 additional
bytes of padding are added. This
extra data is not transmitted