Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9311/LAN9311i
131
Revision 1.4 (08-19-08)
DATASHEET
9.8.6.2
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”
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’.
Figure 9.6 TX Example 2
TX Command 'A'
0
31
TX Command 'B'
Data Written to the
Memory Mapped
TX Data FIFO Port
TX Command 'B'
183-Byte Payload Data
Data Start Offset = 6
First Segment = 1
Last Segment = 1
Buffer Size =183
Packet Length = 183
TX Command 'A'
TX Command 'B'
Data Passed to the
TX Data FIFO
Buffer End Alignment = 0
3B End Padding
TX Command 'A'
6-Byte Data Start Offset
183-Byte Payload Data
NOTE: Extra bytes between buffers
are not transmitted