LAN9221_12 Datasheet, PDF (24/151 Pages) SMSC Corporation – High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O

High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O
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 LAN9221/LAN9221i 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.
Table 3.1 Address Filtering Modes
MCPAS
PRMS
INVFILT
HO
0
0
0
0
0
0
0
0
HPFILT
0
1
DESCRIPTION
MAC address perfect filtering only
for all addresses.
MAC address perfect filtering for
physical address and hash filtering
for multicast addresses
Revision 2.9 (03-01-12)
24
DATASHEET
SMSC LAN9221/LAN9221i