lan9311 Standard Microsystems Corp., lan9311 Datasheet - Page 131

• Manufacturer Part Number: lan9311
• Description: Lan9311/lan9311i Two Port 10/100 Managed Ethernet Switch With 16-bit Non-pci Cpu Interface
• Manufacturer: Standard Microsystems Corp.

Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9311/LAN9311i
9.8.6.2
TX Command 'A'
Buffer End Alignment = 0
Data Start Offset = 6
First Segment = 1
Last Segment = 1
Buffer Size =183
TX Command 'B'
Packet Length = 183
TX Example 2
In this example, a single 183-Byte Ethernet packet will be transmitted. This packet is in a single buffer
as follows:
Figure 9.6
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’.
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
31
Data Written to the
TX Data FIFO Port
6-Byte Data Start Offset
183-Byte Payload Data
Memory Mapped
TX Command 'A'
TX Command 'B'
3B End Padding
Figure 9.6 TX Example 2
DATASHEET
131
0
NOTE: Extra bytes between buffers
are not transmitted
Data Passed to the
183-Byte Payload Data
TX Data FIFO
TX Command 'A'
TX Command 'B'
Revision 1.2 (04-08-08)