KSZ8893FQL-FX Micrel Inc, KSZ8893FQL-FX Datasheet - Page 34

• Manufacturer Part Number: KSZ8893FQL-FX
• Description: 2+1 Port 10/100 Switch W/Tranceivers & Frame Buffers, ( )
• Manufacturer: Micrel Inc

Specifications of KSZ8893FQL-FX

• Controller Type: Ethernet Switch Controller
• Interface: MII, RMII, SNI
• Voltage - Supply: 3.1 V ~ 3.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Number Of Primary Switch Ports: 3
• Internal Memory Buffer Size: 32
• Operating Supply Voltage (typ): 3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Power Supply Type: Analog/Digital
• Package Type: PQFP
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Pin Count: 128
• Mounting: Surface Mount
• Jtag Support: No
• Operating Temperature Classification: Commercial
• Data Rate: 1000Mbps
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1603 - EVAL KIT EXPERIMENTAL KSZ8893MQL
• Current - Supply: -
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-3273

Micrel, Inc.
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 KSZ8893FQL is guaranteed to learn 1K addresses and distinguishes itself from hash-based look-up tables, which
depending upon the operating environment and probabilities, may not guarantee the absolute number of addresses it
can learn.
Learning
The internal look-up engine updates its table with a new entry if the following conditions are met:
The lookup engine inserts the qualified SA into the table, along with the port number and time stamp. If the table is full,
then the last entry of the table is deleted to make room for the new entry.
Migration
The internal look-up engine also monitors whether a station has moved. If a station has moved, it will update the table
accordingly. Migration occurs when the following conditions are met:
The lookup engine will update the existing record in the table with the new source port information.
Aging
The look-up 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 look-up engine removes the
record from the table. The look-up 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 KSZ8893FQL forwards packets using the algorithm that is depicted in the following flowcharts. Figure 7 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 8. The packet is sent to PTF2.
October 2007
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.
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.
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KSZ8893FQL