LAN9211 datasheet(23/147 Pages) SMSC

23 / 147 page

High-Performance Small Form Factor Single-Chip Ethernet Controller with HP Auto-MDIX Support

Datasheet

SMSC LAN9211

Revision 2.9 (03-01-12)

DATASHEET

3.3

Address Filtering Functional Description

The Ethernet address fields of an Ethernet Packet, consists of two 6-byte fields: one for the destination

address and one for the source address. The first bit of the destination address signifies whether it is

a physical address or a multicast address.

The LAN9211 address check logic filters the frame based on the Ethernet receive filter mode that has

been enabled. Filter modes are specified based on the state of the control bits in Table 3.1, "Address

Filtering Modes", which shows the various filtering modes used by the Ethernet MAC Function. These

bits are defined in more detail in the “MAC Control Register”. Please refer to Section 5.4.1,

"MAC_CR—MAC Control Register" for more information on this register.

If the frame fails the filter, the Ethernet MAC function does not receive the packet. The host has the

option of accepting or ignoring the packet.

Figure 3.1 VLAN Frame

Table 3.1 Address Filtering Modes

MCPAS

PRMS

INVFILT

HPFILT

DESCRIPTION

MAC address perfect filtering only

for all addresses.

MAC address perfect filtering for

physical address and hash filtering

for multicast addresses

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