SMSC LAN9311 User Manual

Page of 460
Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9311/LAN9311i
385
Revision 1.4 (08-19-08)
DATASHEET
 
14.5.3.16
Switch Engine Global Ingress Configuration Register (SWE_GLOBAL_INGRSS_CFG)
This register is used to configure the global ingress rules.
Register #:
1840h
Size:
32 bits
BITS
DESCRIPTION
TYPE
DEFAULT
31:14
RESERVED
RO
-
13
Allow Snoop Echo
When set, snooped packets are allowed to be echoed back to the source 
port. When cleared, snooped packets, like other packets, are never sent 
back to the source port.
This bit is useful when the snoop port wishes to receive it’s own MLD/IGMP 
packets.
R/W
0b
12:10
MLD/IGMP Snoop Port
This field is the port bit map where IPv6 MLD packets and IPv4 IGMP 
packets are sent.
R/W
0b
9
Use IP
When set, the IPv4 TOS or IPv6 SC field is enabled as a transmit priority 
queue choice.
R/W
0b
8
Enable MLD Snooping
When set, IPv6 Multicast Listening Discovery packets are snooped and sent 
to the MLD/IGMP snoop port.
R/W
0b
7
Enable IGMP Snooping
When set, IPv4 IGMP packets are snooped and sent to the MLD/IGMP 
snoop port.
R/W
0b
6
SWE Counter Test
When this bit is set the Switch Engine counters that normally clear to 0 when 
read will be set to 7FFF_FFFCh when read.
R/W
0b
5
DA Highest Priority
When this bit is set and the Static bit in the ALR table for the destination 
MAC address is set, the transmit priority queue that is selected is taken from 
the ALR Priority bits (see the 
). 
R/W
0b
4
Filter Multicast
When this bit is set, packets with a multicast destination address are filtered 
if the address is not found in the ALR table. Broadcasts are not included in 
this filter.
R/W
0b
3
Drop Unknown
When this bit is set, packets with a unicast destination address are filtered 
if the address is not found in the ALR table.
R/W
0b
2
Use Precedence
When the priority is taken from an IPV4 packet (enabled via the Use IP bit), 
this bit selects between precedence bits in the TOS octet or the DIFFSERV 
table.
When set, IPv4 packets will use the precedence bits in the TOS octet to 
select the transmit priority queue. When cleared, IPv4 packets will use the 
DIFFSERV table to select the transmit priority queue.
R/W
1b