High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface

Datasheet

14.5.3.16Switch Engine Global Ingress Configuration Register (SWE_GLOBAL_INGRSS_CFG)

Register #:

1840h

Size:

32 bits

This register is used to configure the global ingress rules.

BITS

DESCRIPTION

TYPE

DEFAULT

 

 

 

 

31:14

RESERVED

RO

-

 

 

 

 

13

Allow Snoop Echo

R/W

0b

 

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.

 

 

 

 

 

 

12:10

MLD/IGMP Snoop Port

R/W

0b

 

This field is the port bit map where IPv6 MLD packets and IPv4 IGMP

 

 

 

packets are sent.

 

 

 

 

 

 

9

Use IP

R/W

0b

 

When set, the IPv4 TOS or IPv6 SC field is enabled as a transmit priority

 

 

 

queue choice.

 

 

 

 

 

 

8

Enable MLD Snooping

R/W

0b

 

When set, IPv6 Multicast Listening Discovery packets are snooped and sent

 

 

 

to the MLD/IGMP snoop port.

 

 

 

 

 

 

7

Enable IGMP Snooping

R/W

0b

 

When set, IPv4 IGMP packets are snooped and sent to the MLD/IGMP

 

 

 

snoop port.

 

 

 

 

 

 

6

SWE Counter Test

R/W

0b

 

When this bit is set the Switch Engine counters that normally clear to 0 when

 

 

 

read will be set to 7FFF_FFFCh when read.

 

 

 

 

 

 

5

DA Highest Priority

R/W

0b

 

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 Switch Engine ALR Read Data 1 Register

 

 

 

(SWE_ALR_RD_DAT_1)).

 

 

 

 

 

 

4

Filter Multicast

R/W

0b

 

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.

 

 

 

 

 

 

3

Drop Unknown

R/W

0b

 

When this bit is set, packets with a unicast destination address are filtered

 

 

 

if the address is not found in the ALR table.

 

 

 

 

 

 

2

Use Precedence

R/W

1b

 

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.

 

 

 

 

 

 

SMSC LAN9312

383

Revision 1.4 (08-19-08)

 

DATASHEET