LAN9353 Datasheet, PDF (291/523 Pages) Microchip Technology – Interfaces at up to 200Mbps via Turbo MII

LAN9353
10.7.3.5 Switch Engine ALR Read Data 1 Register (SWE_ALR_RD_DAT_1)
Register #:
1806h
Size:
32 bits
This register is used in conjunction with the Switch Engine ALR Read Data 0 Register (SWE_ALR_RD_DAT_0) to read
the ALR table. It contains the last 32 bits of the ALR entry and is loaded via the Get First Entry or Get Next Entry com-
mands in the Switch Engine ALR Command Register (SWE_ALR_CMD). This register is only valid when either of the
Valid or End of Table bits are set.
Bits
31:28
27
26
25
Description
RESERVED
End of Table
This bit indicates that the end of the ALR table has been reached and further
Get Next Entry commands are not required.
Note: The Valid bit may or may not be set when the end of the table is
reached.
Valid
This bit clears when the Get First Entry or Get Next Entry bits of the Switch
Engine ALR Command Register (SWE_ALR_CMD) are written. This bit sets
when a valid entry is found in the ALR table. This bit stays cleared if the top of
the ALR table is reached without finding an entry.
Age 1/Override
This bit is used by the aging and forwarding processes.
If the Static bit of this register is cleared, this bit is the msb of the aging timer.
Software should set this bit 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 (except the Disabled state) of the
ingress or egress port(s). This is typically used to allow the reception of
BPDU packets in the non-forwarding state.
24 Static
Indicates that this entry will not be removed by the aging 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.
23 Age 0/Filter
This bit is used by the aging and forwarding processes.
If the Static bit of this register is cleared, this bit is the lsb of the aging timer.
Software should set this bit so that the entry will age in the normal amount of
time.
If the Static bit is set, this bit is used to filter packets. When set, packets with
a destination address that matches this MAC address will be filtered.
22 Priority Enable
Indicates whether or not the usage of the Priority field is enabled for this MAC
address entry.
Type
RO
RO
RO
RO
RO
RO
RO
Default
-
0b
0b
0b
0b
0b
0b
 2015 Microchip Technology Inc.
DS00001925A-page 291