KSZ8842-PMBL Micrel Inc, KSZ8842-PMBL Datasheet - Page 54

• Manufacturer Part Number: KSZ8842-PMBL
• Description: 2-Port Ethernet Switch/Repeater + 32-bit/33MHz PCI Bus Interface ( )
• Manufacturer: Micrel Inc

Specifications of KSZ8842-PMBL

• Controller Type: Ethernet Switch Controller
• Interface: PCI
• Voltage - Supply: 3.1 V ~ 3.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 100-LFBGA
• Number Of Primary Switch Ports: 2
• Internal Memory Buffer Size: 32
• Operating Supply Voltage (typ): 3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII
• Power Supply Type: Analog/Digital
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Mounting: Surface Mount
• Jtag Support: No
• Operating Supply Voltage (max): 3.5V
• Operating Supply Voltage (min): 3.1V
• Operating Temperature Classification: Commercial
• Data Rate: 100Mbps
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1636 - BOARD EVALUATION KSZ8842-PMQL
• Current - Supply: -
• Lead Free Status / RoHS Status: Supplier Unconfirmed, Lead free / RoHS Compliant
• Other names: 576-3089

Micrel, Inc.
Switch Global Control Register 2 (Offset 0x0404): SGCR2
This register contains the global control for the switch function.
October 2007
10 – 9
Bit
15
14
13
12
11
8
7
6
5
4
Default
0
0
0
0
0
0
0
1
1
1
1
R/W
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
Description
802.1Q VLAN enable
1 = 802.1Q VLAN mode is turned on. VLAN table needs to set up before
the operation.
0 = 802.1Q VLAN is disabled.
IGMP snoop enable
1 = IGMP snoop is enabled. All the IGMP packets will be forwarded to the
host port.
0 = IGMP snoop is disabled.
IPv6 MLD snooping enable
1 = enable IPv6 MLD snooping
IPv6 MLD snooping option
1 = enable IPv6 MLD snooping option.
Priority Scheme select
0 = always TX higher priority packets first
1 = Weighted Fair Queuing enable. When all 4 queues has packets
waiting to TX, the bandwidth allocation is q3:q2:q1:q0 = 8:4:2:1. If any
queues is empty, the highest non-empty queue will get one more
weighting. For example, if q2 is empty, q3:q2:q1:q0 will become (8+1): 0
:2 : 1.
Reserved.
For factory test purposes only. Always write 0.
Sniff mode select
1 = will do RX AND TX sniff (both source port and destination port need to
match)
0 = will do RX OR TX sniff (Either source port or destination port needs to
match). This is the mode used to implement rx only sniff.
Unicast port-VLAN mismatch discard
1 = all packets can not cross VLAN boundary
0 = unicast packets (excluding unknown/multicast/broadcast) can cross
VLAN boundary
Multicast storm protection disable
1 = “Broadcast Storm Protection” does not include multicast packets. Only
DA = FFFFFFFFFFFF packets will be regulated.
0 = “Broadcast Storm Protection” includes DA = FFFFFFFFFFFF and
DA[40] = 1 packets.
Back pressure mode
1 = carrier sense based backpressure is selected
0 = collision based backpressure is selected
Flow control and back pressure fair mode
1 = fair mode is selected. In this mode, if a flow control port and a non-
flow control port talk to the same destination port, packets from the non-
flow control port may be dropped. This is to prevent the flow control port
from being flow controlled for an extended period of time.
0 = in this mode, if a flow control port and a non-flow control port talk to
the same destination port, the flow control port will be flow controlled.
This may not be “fair” to the flow control port.
54
KSZ8842-PMQL/PMBL
M9999-100207-1.5