LAN9220 datasheet(49/142 Pages) MICROCHIP

Part #	LAN9220

Description	16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support

PDF	142 Pages

Scroll/Zoom	100%

Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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49 / 142 page

 2006-2017 Microchip Technology Inc.

DS00002417A-page 49

LAN9220

3.12.6.3

TX Example 3

In this example a single, 111-Byte Ethernet packet will be transmitted with a TX checksum. This packet is divided into

four buffers. The four buffers are as follows:

Buffer 0:

• 4-Byte “Data Start Offset”

• 4-Byte Checksum Preamble

• 16-Byte “Buffer End Alignment”

Buffer 1:

• 7-Byte “Data Start Offset”

• 79-Bytes of payload data

• 16-Byte “Buffer End Alignment”

Buffer 2:

• 0-Byte “Data Start Offset”

• 15-Bytes of payload data

• 16-Byte “Buffer End Alignment”

Buffer 3:

• 10-Byte “Data Start Offset”

• 17-Bytes of payload data

• 16-Byte “Buffer End Alignment”

Figure 3-21, "TX Example 1" illustrates the TX command structure for this example, and also shows how data is passed

to the TX data FIFO.

Note:

In order to perform a TX checksum calculation on the associated packet, bit 14 (CK) of the TX Command

‘B’ must be set in conjunction with bit 13 (FS) of TX Command ‘A’ and bit 16 (TXCOE_EN) of the COE_CR

LAN9220 Datasheet(PDF) 49 Page - Microchip Technology