DM8603EP DAVICOM [Davicom Semiconductor, Inc.], DM8603EP Datasheet - Page 71

• Manufacturer Part Number: DM8603EP
• Description: 10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
• Manufacturer: DAVICOM [Davicom Semiconductor, Inc.]

9.2 Switch Functions
9.2.1
time. DM8603 stores MAC addresses, port number and time stamp information in the Hash-based Address
Table. It can learn up to 1K unicast address entries.
not exist and incoming packet is valid (non-error and legal length).
REG 08h/09h/0Ah.11h.[12].
9.2.2
time stamp whenever the corresponding SA receives. The switch engine would delete the entry if its time
stamp is not updated for a period of time. The period can be programmed or disabled through
REG 10h.15h.[1:0].
9.2.3
9.2.4
other word, the value is 9.6u sec for 10Mbps and 960n sec for 100Mbps.
9.2.5
IEEE standard 802.3.
Preliminary datasheet
DM8603-12-DS-P01
November 8, 2010
The DM8603 has a self-learning mechanism for learning the MAC addresses of incoming packets in real
The switch engine updates address table with new entry if incoming packet’s Source Address (SA) does
Besides, DM8603 has an option to disable address learning for individual port. This feature can be set by
The time stamp information of address table is used in the aging process. The switch engine updates
The DM8603 forwards the incoming packet according to following decision:
The DM8603 will filter incoming packets under following conditions:
IPG is the idle time between any two valid packets at the same port. The typical number is 96 bits time. In
The DM8603 implements the binary exponential back-off algorithm in half-duplex mode compliant to
Address Learning
Address Aging
Packet Forwarding
Inter-Packet Gap (IPG)
Back-off Algorithm
If DA is Multicast/Broadcast, the packet is forwarded to all ports, except to the port on which the
packet was received.
Switch engine would look up address table based on DA when incoming packets is UNICAST. If the
DA was not found in address table, the packet is treated as a multicast packet and forward to other
ports. If the DA was found and its destination port number is different to source port number, the
packet is forward to destination port.
Switch engine also look up VLAN, Port Monitor setting and other forwarding constraints for the
forwarding decision, more detail will discuss in later sections.
Error packets, including CRC errors, alignment errors, illegal size errors.
PAUSE packets.
If incoming packet is UNICAST and its destination port number is equal to source port number.
10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
DM8603
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