SMSC LAN9312 - Manual (Page 368)

High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
Revision 1.4 (08-19-08) 368 SMSC LAN9312
DATASHEET
14.5.3.3 Switch Engine ALR Write Data 1 Register (SWE_ALR_WR_DAT_1)
This register is used in conjunction with the Switch Engine ALR Write Data 0 Register
(SWE_ALR_WR_DAT_0) and contains the last 32 bits of ALR data to be manually written via the Make
Entry command in the Switch Engine ALR Command Register (SWE_ALR_CMD) .
Register #: 1802h Size: 32 bits
BITS DESCRIPTION TYPE DEFAULT
31:25 RESERVED RO -
24 Valid
When set, this bit makes the entry valid. It can be cleared to invalidate a
previous entry that contained the specified MAC address. R/W 0b
23 Age/Override
This bit is used by the aging and forwarding processes.
If the Static bit of this register is cleared, this bit should be set so that the
entry will age in the normal amount of time.
If the Static bit is set, this bit is used as a port state override bit. When set,
packets received with a destination address that matches the MAC address
in the SWE_ALR_WR_DAT_1 and SWE_ALR_WR_DAT_0 registers will be
forwarded regardless of the port state of the ingress or egress port(s). This
is typically used to allow the reception of BPDU packets in the non-
forwarding state.
R/W 0b
22 Static
When this bit is set, this entry will not be removed by the aging process
and/or be changed by the learning process. When this bit is cleared, this
entry will be automatically removed after 5 to 10 minutes of inactivity.
Inactivity is defined as no packets being received with a source address that
matches this MAC address.
Note: This bit is normally set when adding manual entries. It must be
cleared when removing an entry (clearing the Valid bit).
R/W 0b
21 Filter
When set, packets with a destination address that matches this MAC
address will be filtered. R/W 0b
20:19 Priority
These bits specify the priority that is used for packets with a destination
address that matches this MAC address. This priority is only used if the
Static bit of this register is set, and the DA Highest Priority (bit 5) in the
Switch Engine Global Ingress Configuration Register
(SWE_GLOBAL_INGRSS_CFG)
is set.
R/W 00b