LAN9218 Datasheet, PDF (23/130 Pages) SMSC Corporation – High-Performance Single- Chip 10/100 Ethernet Controller with HP Auto-MDIX

High-Performance Single-Chip 10/100 Ethernet Controller with HP Auto-MDIX
Datasheet
Figure 3.1 VLAN Frame
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 LAN9218 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," on page 94 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.
Table 3.1 Address Filtering Modes
MCPAS
PRMS
INVFILT
HO
HPFILT
DESCRIPTION
0
0
0
0
0
MAC address perfect filtering only
for all addresses.
0
0
0
0
1
MAC address perfect filtering for
physical address and hash filtering
for multicast addresses
SMSC LAN9218
23
DATASHEET
Revision 1.5 (07-18-06)