LAN9311 Datasheet, PDF (131/461 Pages) SMSC Corporation – Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface

9.8.6.2
Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface
Datasheet
TX Example 2
In this example, a single 183-Byte Ethernet packet will be transmitted. This packet is in a single buffer
as follows:
 2-Byte “Data Start Offset”
 183-Bytes of payload data
 4-Byte “Buffer End Alignment”
Figure 9.6 illustrates the TX command structure for this example, and also shows how data is passed
to the TX Data FIFO. Note that the packet resides in a single TX Buffer, therefore both the FS and LS
bits are set in TX command ‘A’.
TX Command 'A'
Buffer End Alignment = 0
Data Start Offset = 6
First Segment = 1
Last Segment = 1
Buffer Size =183
Data Written to the
Memory Mapped
TX Data FIFO Port
31
0
TX Command 'A'
TX Command 'B'
6-Byte Data Start Offset
TX Command 'B'
Packet Length = 183
Data Passed to the
TX Data FIFO
TX Command 'A'
TX Command 'B'
183-Byte Payload Data
183-Byte Payload Data
SMSC LAN9311/LAN9311i
3B End Padding
Figure 9.6 TX Example 2
NOTE: Extra bytes between buffers
are not transmitted
131
DATASHEET
Revision 2.0 (02-14-13)