KSZ8873MLL Micrel Inc, KSZ8873MLL Datasheet - Page 33
![IC ETHERNET SWITCH 3PORT 64-LQFP](/photos/6/81/68149/64-lqfp-micrel_sml.jpg)
KSZ8873MLL
Manufacturer Part Number
KSZ8873MLL
Description
IC ETHERNET SWITCH 3PORT 64-LQFP
Manufacturer
Micrel Inc
Specifications of KSZ8873MLL
Data Rate
100Mbps
Controller Type
Ethernet Switch Controller
Interface
MII
Voltage - Supply
1.8V, 2.5V, 3.3V
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
64-LQFP
No. Of Ports
3
Ethernet Type
IEEE 802.3u
Supply Current
115mA
Supply Voltage Range
2.5V, 3.3V
Digital Ic Case Style
LQFP
No. Of Pins
64
Svhc
No SVHC (15-Dec-2010)
Base
RoHS Compliant
Number Of Primary Switch Ports
3
Internal Memory Buffer Size
32
Fiber Support
No
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)
1.89/3.465V
Operating Temperature Classification
Commercial
Interface Type
MII, RMII
Operating Temperature Range
0°C To +70°C
Rohs Compliant
Yes
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Supply
-
Lead Free Status / RoHS Status
Compliant, Lead free / RoHS Compliant
Other names
576-3459
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
KSZ8873MLL
Manufacturer:
Micrel Inc
Quantity:
1 934
Company:
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KSZ8873MLL
Manufacturer:
ADI
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Part Number:
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Micrel
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Company:
Part Number:
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Manufacturer:
Micrel
Quantity:
323
Micrel, Inc.
QoS Priority Support
The KSZ8873MLL/FLL/RLL provides Quality of Service (QoS) for applications such as VoIP and video conferencing.
Offering four priority queues per port, the per-port transmit queue can be split into four priority queues: Queue 3 is the
highest priority queue and Queue 0 is the lowest priority queue. Bit [0] of registers 16, 32 and 48 is used to enable split
transmit queues for ports 1, 2 and 3, respectively. If a port's transmit queue is not split, high priority and low priority
packets have equal priority in the transmit queue.
There is an additional option to either always deliver high priority packets first or use weighted fair queuing for the four
priority queues. This global option is set and explained in bit [3] of register 5.
Port-Based Priority
With port-based priority, each ingress port is individually classified as a high priority receiving port. All packets received at
the high priority receiving port are marked as high priority and are sent to the high-priority transmit queue if the
corresponding transmit queue is split. Bits [4:3] of registers 16, 32 and 48 are used to enable port-based priority for ports
1, 2 and 3, respectively.
802.1p-Based Priority
For 802.1p-based priority, the KSZ8873MLL/FLL/RLL examines the ingress (incoming) packets to determine whether they
are tagged. If tagged, the 3-bit priority field in the VLAN tag is retrieved and compared against the “priority mapping” value,
as specified by the registers 12 and 13. The “priority mapping” value is programmable.
The following figure illustrates how the 802.1p priority field is embedded in the 802.1Q VLAN tag.
802.1p-based priority is enabled by bit [5] of registers 16, 32 and 48 for ports 1, 2 and 3, respectively.
The KSZ8873MLL/FLL/RLL provides the option to insert or remove the priority tagged frame's header at each individual
egress port. This header, consisting of the 2 bytes VLAN Protocol ID (VPID) and the 2-byte Tag Control Information field
(TCI), is also referred to as the IEEE 802.1Q VLAN tag.
Tag Insertion is enabled by bit [2] of registers 16, 32 and 48 for ports 1, 2 and 3, respectively. At the egress port,
untagged packets are tagged with the ingress port’s default tag. The default tags are programmed in register sets {19,20},
{35,36} and {51,52} for ports 1, 2 and 3, respectively and the source port VID has to be inserted at selected egress ports
by bit[5:0] of register 194. The KSZ8873MLL/FLL/RLL will not add tags to already tagged packets.
Tag Removal is enabled by bit [1] of registers 16, 32 and 48 for ports 1, 2 and 3, respectively. At the egress port, tagged
packets will have their 802.1Q VLAN Tags removed. The KSZ8873MLL/FLL/RLL will not modify untagged packets.
The CRC is recalculated for both tag insertion and tag removal.
802.1p Priority Field Re-mapping is a QoS feature that allows the KSZ8873MLL/FLL/RLL to set the “User Priority
Ceiling” at any ingress port. If the ingress packet’s priority field has a higher priority value than the default tag’s priority
field of the ingress port, the packet’s priority field is replaced with the default tag’s priority field.
September 2009
Bytes
802.1q VLAN Tag
Preamble
8
Bits
DA
6
Tagged Packet Type
(8100 for Ethernet)
16
Figure 6. 802.1p Priority Field Format
SA
6
VPID
2
802.1p
TCI
2
3
1
33
length
2
VLAN ID
12
LLC
46-1500
Data
KSZ8873MLL/FLL/RLL
FCS
M9999-092309-1.2
4