KSZ8873MLL Micrel Inc, KSZ8873MLL Datasheet - Page 37
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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:
Part Number:
KSZ8873MLL
Manufacturer:
ADI
Quantity:
27
Company:
Part Number:
KSZ8873MLL AM
Manufacturer:
Micrel
Quantity:
1 638
Company:
Part Number:
KSZ8873MLLJ
Manufacturer:
Micrel
Quantity:
323
Micrel, Inc.
KSZ8873MLL/FLL/RLL
Multiple ports can be selected as “receive sniff” or “transmit sniff”. In addition, any port can be selected as the “sniffer port”.
All these per port features can be selected through registers 17, 33 and 49 for ports 1, 2 and 3, respectively.
Rate Limiting Support
The KSZ8873MLL/FLL/RLL provides a fine resolution hardware rate limiting from 64Kbps to 99Mbps. The rate step is
64Kbps when the rate range is from 64Kbps to 960Kbps and 1Mbps for 1Mbps to 100Mbps(100BT) or to 10Mbps(10BT)
(refer to Data Rate Limit Table). The rate limit is independently on the “receive side” and on the “transmit side” on a per
port basis. For 10BASE-T, a rate setting above 10 Mbps means the rate is not limited. On the receive side, the data
receive rate for each priority at each port can be limited by setting up Ingress Rate Control Registers. On the transmit side,
the data transmit rate for each priority queue at each port can be limited by setting up Egress Rate Control Registers. The
size of each frame has options to include minimum IFG (Inter Frame Gap) or Preamble byte, in addition to the data field
(from packet DA to FCS).
For ingress rate limiting, KSZ8873MLL/FLL/RLL provides options to selectively choose frames from all types, multicast,
broadcast, and flooded unicast frames. The KSZ8873MLL/FLL/RLL counts the data rate from those selected type of
frames. Packets are dropped at the ingress port when the data rate exceeds the specified rate limit.
For egress rate limiting, the Leaky Bucket algorithm is applied to each output priority queue for shaping output traffic. Inter
frame gap is stretched on a per frame base to generate smooth, non-burst egress traffic. The throughput of each output
priority queue is limited by the egress rate specified.
If any egress queue receives more traffic than the specified egress rate throughput, packets may be accumulated in the
output queue and packet memory. After the memory of the queue or the port is used up, packet dropping or flow control
will be triggered. As a result of congestion, the actual egress rate may be dominated by flow control/dropping at the
ingress end, and may be therefore slightly less than the specified egress rate.
To reduce congestion, it is a good practice to make sure the egress bandwidth exceeds the ingress bandwidth.
Unicast MAC Address Filtering
The unicast MAC address filtering function works in conjunction with the static MAC address table. First, the static MAC
address table is used to assign a dedicated MAC address to a specific port. If a unicast MAC address is not recorded in
the static table, it is also not learned in the dynamic MAC table. The KSZ8873MLL/FLL/RLL is then configured with the
option to either filter or forward unicast packets for an unknown MAC address. This option is enabled and configured in
register 14.
This function is useful in preventing the broadcast of unicast packets that could degrade the quality of the port in
applications such as voice over Internet Protocol (VoIP).
Configuration Interface
The KSZ8873MLL/FLL/RLL can operate as both a managed switch and an unmanaged switch.
In unmanaged mode, the KSZ8873MLL/FLL/RLL is typically programmed using an EEPROM. If no EEPROM is present,
the KSZ8873MLL/FLL/RLL is configured using its default register settings. Some default settings are configured via strap-
in pin options. The strap-in pins are indicated in the “Pin Description and I/O Assignment” table.
2
I
C Master Serial Bus Configuration
2
With an additional I
C (“2-wire”) EEPROM, the KSZ8873MLL/FLL/RLL can perform more advanced switch features like
“broadcast storm protection” and “rate control” without the need of an external processor.
2
For KSZ8873MLL/FLL/RLL I
C Master configuration, the EEPROM stores the configuration data for register 0 to register
120 (as defined in the KSZ8873MLL/FLL/RLL register map) with the exception of the “Read Only” status registers. After
the de-assertion of reset, the KSZ8873MLL/FLL/RLL sequentially reads in the configuration data for all control registers,
starting from register 0.
September 2010
37
M9999-092309-1.2