LAN9220 Datasheet, PDF (50/150 Pages) SMSC Corporation – 16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support

16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support
Datasheet
init
Last Buffer in
Packet
Idle
Check
available
FIFO
space
TX Status
Available
Read TX
Status
(optional)
Write
TX
Command
Write
Start
Padding
(optional)
Write
Buffer
Not Last Buffer
Figure 3.13 Simplified Host TX Flow Diagram
3.12.1
TX Buffer Format
TX buffers exist in the host’s memory in a given format. The host writes a TX command word into the
TX data buffer before moving the Ethernet packet data. The TX command A and command B are 32-
bit values that are used by the LAN9220 in the handling and processing of the associated Ethernet
packet data buffer. Buffer alignment, segmentation and other packet processing parameters are
included in the command structure. The following diagram illustrates the buffer format.
Revision 2.6 (12-04-08)
50
DATASHEET
SMSC LAN9220