lan9312 Standard Microsystems Corp., lan9312 Datasheet - Page 129

• Manufacturer Part Number: lan9312
• Description: Lan9312 High Performance Two Port 10/100 Managed Ethernet Switch With 32-bit Non-pci Cpu Interface
• Manufacturer: Standard Microsystems Corp.

High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312
Figure 9.5
to the TX Data FIFO.
TX Command 'A'
Buffer End Alignment = 1
Data Start Offset = 7
First Segment = 1
Last Segment = 0
Buffer Size = 79
TX Command 'B'
Packet Length = 111
TX Command 'A'
Buffer End Alignment = 1
Data Start Offset = 0
First Segment = 0
Last Segment = 0
Buffer Size = 15
TX Command 'B'
Packet Length = 111
TX Command 'A'
Buffer End Alignment = 1
Data Start Offset = 10
First Segment = 0
Last Segment = 1
Buffer Size = 17
TX Command 'B'
Packet Length = 111
17-Bytes of payload data
16-Byte “Buffer End Alignment”
illustrates the TX command structure for this example, and also shows how data is passed
31
31
31
Data Written to the
TX Data FIFO Port
Memory Mapped
7-Byte Data Start Offset
17-Byte Payload Data
5-Byte End Padding
End Offset Padding
TX Command 'A'
TX Command 'B'
TX Command 'A'
TX Command 'B'
TX Command 'A'
TX Command 'B'
Data Start Offset
79-Byte Payload
15-Byte Payload
Pad DWORD 1
End Padding
10-Byte
10-Byte
10-Byte
Figure 9.5 TX Example 1
DATASHEET
1B
129
0
0
0
Data Passed to the
TX Data FIFO
TX Command 'A'
TX Command 'B'
79-Byte Payload
TX Command 'A'
15-Byte Payload
TX Command 'A'
17-Byte Payload
NOTE: Extra bytes
between buffers are
not transmitted
Revision 1.2 (04-08-08)