KS8995MA-EVAL Micrel Inc, KS8995MA-EVAL Datasheet - Page 25

• Manufacturer Part Number: KS8995MA-EVAL
• Description: BOARD EVAL EXPERIMENT KS8995MA
• Manufacturer: Micrel Inc

Specifications of KS8995MA-EVAL

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 576-1018

Semptember 2008
advertisements, the receiver is listening for advertisements or a fixed signal protocol.
The flow for the link setup is shown in Figure 5.
Functional Overview: Switch Core
Address Look-Up
The internal look-up table stores MAC addresses and their associated information. It contains a 1K unicast address
table plus switching information. The KS8995MA/FQ is guaranteed to learn 1K addresses and distinguishes itself
from a hash-based look-up table, which depending on 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 look-up 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 first to make room for the new entry.
Migration
The internal look-up engine also monitors whether a station is moved. If this occurs, it updates the table accordingly.
Migration happens when the following conditions are met:
The look-up engine will update the existing record in the table with the new source port information.
Aging
The look-up engine will update 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 will
remove the record from the table. The look-up engine constantly performs the aging process and will continuously
remove aging records. The aging period is 300 + 75 seconds. This feature can be enabled or disabled through
Register 3 or by external pull-up or pull-down resistors on LED[5][2]. See “Register 3” section.
Forwarding
The KS8995MA/FQ will forward packets using an algorithm that is depicted in the following flowcharts. Figure 6
shows stage one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and
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The received packet’s source address (SA) does not exist in the look-up table.
The received packet is good; the packet has no receiving errors and is of legal length.
The received packet’s SA is in the table but the associated source port information is different.
The received packet is good; the packet has no receiving errors and is of legal length.
and Set Link Mode
Force Link Setting
Auto Negotiation
Auto-Negotiation
Bypass
Start
Yes
Figure 5. Auto-Negotiation
Auto-Negotiation
Attempt
No
100BASE-TX Idles
Link Mode Set ?
Link Mode Set
25
Operation
Listen for
Join Flow
Parallel
Yes
Listen for 10BASE-T
Link Pulses
No
M9999-091508