lan9220 Standard Microsystems Corp., lan9220 Datasheet - Page 116

• Manufacturer Part Number: lan9220
• Description: 16-bit Non-pci Small Form Factor 10/100 Ethernet Controller With Variable Voltage I/o & Hp Auto-mdix Support
• Manufacturer: Standard Microsystems Corp.

Revision 2.6 (12-04-08)
5.4.13
31-17
BITS
15-2
16
1
0
Reserved
TX Checksum Offload Engine Enable (TXCOE_EN). This bit enables/disables the Transmit COE.
This bit may only be changed if the TX data path is disabled.
0: The TXCOE is bypassed
1: The TXCOE is enabled
Reserved
RX Checksum Offload Engine Mode (RXCOE_MODE) This register indicates whether the RXCOE
will check for VLAN tags or a SNAP header prior to beginning its checksum calculation. In its default
mode, the calculation will always begin 14 bytes into the frame.
The RXCOE_MODE may only be changed if the ESS RX path is disabled.
0: Begin checksum calculation after first 14 bytes of Ethernet Frame
1: Begin checksum calculation at start of L3 packet by adjusting for VLAN tags and/or SNAP header.
RX Checksum Offload Engine Enable (RXCOE_EN). This bit enables/disables the Receive COE.
This bit may only be changed if the RX data path is disabled.
0: The RXCOE is bypassed
1: The RXCOE is enabled
Note:
COE_CR—Checksum Offload Engine Control Register
This register controls the transmit and receive checksum offload engines.
Offset:
Default Value:
When the RXCOE is enabled, automatic pad stripping must be disabled (bit 8 (PADSTR) of
the
simultaneously.
MAC_CR—MAC Control
16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support
D
00000000h
DATASHEET
Register) and vice versa. These functions cannot be enabled
116
DESCRIPTION
Attribute:
Size:
R/W
32 bits
SMSC LAN9220
Datasheet