KSZ8873MLL Micrel Inc, KSZ8873MLL Datasheet - Page 24
![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:
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
In addition, the KSZ8873MLL/FLL/RLL features a per-port power down mode. To save power, a PHY port that is not in
use can be powered down via port control register 29 or 45 bit 3, or MIIM PHY register.
Functional Overview: MAC and Switch
Address Lookup
The internal lookup table stores MAC addresses and their associated information. It contains a 1K unicast address table
plus switching information.
The KSZ8873MLL/FLL/RLL is guaranteed to learn 1K addresses and distinguishes itself from hash-based lookup tables,
which depending on the operating environment and probabilities, may not guarantee the absolute number of addresses it
can learn.
Learning
The internal lookup engine updates its table with a new entry if the following conditions are met:
1. The received packet's Source Address (SA) does not exist in the lookup table.
2. The received packet is good; the packet has no receiving errors, and is of legal length.
The lookup engine inserts the qualified SA into the table, along with the port number and time stamp. If the table is full, the
last entry of the table is deleted to make room for the new entry.
Migration
The internal lookup engine also monitors whether a station has moved. If a station has moved, it will update the table
accordingly. Migration happens when the following conditions are met:
1. The received packet's SA is in the table but the associated source port information is different.
2. The received packet is good; the packet has no receiving errors, and is of legal length.
The lookup engine will update the existing record in the table with the new source port information.
Aging
The lookup engine updates the time stamp information of a record whenever the corresponding SA appears. The time
stamp is used in the aging process. If a record is not updated for a period of time, the lookup engine removes the record
from the table. The lookup engine constantly performs the aging process and will continuously remove aging records. The
aging period is about 200 seconds. This feature can be enabled or disabled through register 3 (0x03) bit [2].
Forwarding
The KSZ8873MLL/FLL/RLL forwards packets using the algorithm that is depicted in the following flowcharts. Figure 4
shows stage one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and dynamic
table for the destination address, and comes up with “port to forward 1” (PTF1). PTF1 is then further modified by
spanning tree, IGMP snooping, port mirroring, and port VLAN processes to come up with “port to forward 2” (PTF2), as
shown in Figure 5. The packet is sent to PTF2.
September 2009
24
M9999-092309-1.2