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Ethernet Subsystem Registers
14.5.1.12 PORTCTL3 Register (offset = 4Ch) [reset = 0h]
PORTCTL3 is shown in Figure 14-26 and described in Table 14-36.
ADDRESS LOOKUP ENGINE PORT 3 CONTROL REGISTER
Figure 14-26. PORTCTL3 Register
31 30 29 28 27 26 25 24
BCAST_LIMIT
R/W-0
23 22 21 20 19 18 17 16
MCAST_LIMIT
R/W-0
15 14 13 12 11 10 9 8
Reserved
7 6 5 4 3 2 1 0
Reserved NO_SA_UPDATE NO_LEARN VID_INGRESS_CHE DROP_UNTAGGED PORT_STATE
CK
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 14-36. PORTCTL3 Register Field Descriptions
Bit Field Type Reset Description
31-24 BCAST_LIMIT R/W-0 0 Broadcast Packet Rate Limit - Each prescale pulse loads this field
into the port broadcast rate limit counter.
The port counters are decremented with each packet received or
transmitted depending on whether the mode is transmit or receive.
If the counters decrement to zero, then further packets are rate
limited until the next prescale pulse.
Broadcast rate limiting is enabled by a non-zero value in this field
23-16 MCAST_LIMIT R/W-0 0 Multicast Packet Rate Limit - Each prescale pulse loads this field into
the port multicast rate limit counter.
The port counters are decremented with each packet received or
transmitted depending on whether the mode is transmit or receive.
If the counters decrement to zero, then further packets are rate
limited until the next prescale pulse.
Multicast rate limiting is enabled by a non-zero value in this field.
5 NO_SA_UPDATE R/W-0 0 No Souce Address Update - When set the port is disabled from
updating the source port number in an ALE table entry.
4 NO_LEARN R/W-0 0 No Learn Mode - When set the port is disabled from learning an
address.
3 VID_INGRESS_CHECK R/W-0 0 VLAN ID Ingress Check - If VLAN not found then drop the packet.
Packets with an unknown (default) VLAN will be dropped.
2 DROP_UNTAGGED R/W-0 0
Drop Untagged Packets - Drop non-VLAN tagged ingress packets.
1-0 PORT_STATE R/W-0 0 Port State
0 - Disabled
1 - Blocked
2 - Learn
3 - Forward
1253
SPRUH73H–October 2011–Revised April 2013 Ethernet Subsystem
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