KSZ8895MQ_12 MICREL [Micrel Semiconductor], KSZ8895MQ_12 Datasheet - Page 57

• Manufacturer Part Number: KSZ8895MQ_12
• Description: Integrated 5-Port 10/100 Managed Ethernet Switch with MII/RMII interface
• Manufacturer: MICREL [Micrel Semiconductor]

Micrel, Inc.
Global Registers
March 2012
Address
3
2
1
0
Register 4 (0x04): Global Control 2
7
6
5
Name
Frame Length Field
Check
Aging Enable
Fast age Enable
Aggressive Back Off
Enable
Unicast Port-VLAN
Mismatch Discard
Multicast Storm
Protection Disable
Back Pressure Mode
(Continued)
Description
1, will check frame length field in the IEEE packets
If the actual length does not match, the packet will be
dropped (for L/T <1500) .
1, Enable age function in the chip.
0, Disable aging function.
1 = Turn on fast age (800µs).
1 = Enable more aggressive back-off algorithm in half
duplex mode to enhance performance. This is not an
IEEE standard.
This feature is used for port VLAN (described in
Register 17, Register 33...).
1, all packets can not cross VLAN boundary.
0, unicast packets (excluding unknown/
multicast/broadcast) can cross VLAN boundary.
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 packet.
1, carrier sense based backpressure is selected.
0, collision based backpressure is selected.
57
Mode
R/W
R/W
R/W
R/W
R/W
R/W
R/W
KSZ8895MQ/RQ/FMQ
Pin LED[5][2]
strap option.
PD(0): Aging
disable.
PU(1): Aging
enable (default).
Note: LED[5][2]
has internal pull
up.
Pin PMRXD0
strap option.
PD(0): Disable
aggressive back
off (default).
PU(1):
Aggressive back
off.
Note: PMRXD0
has internal pull
down.
M9999-032612-1.5
Default
0
1
0
0
1
1
1