t71l6808a TM Technology Inc., t71l6808a Datasheet - Page 2

• Manufacturer Part Number: t71l6808a
• Description: Octal 10/100 Switch With Embedded Memory
• Manufacturer: TM Technology Inc.

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Preliminary T71L6808A
General Description
The T71L6808A is a highly integrated, octal port, 10-BaseT/100Base-TX, RMII interface, Ethernet
switch implemented in 0.18um CMOS technology. The T71L6808A supports a wide variety of
switch features and configurations at the maximum performance levels with the lowest number of
components per switch.
The switch chip supports store-and-forward switching scheme with built-in storage of incoming/
outgoing packets as well as address table. The T71L6808A adopts page-based memory architecture
in order to fully utilize the embedded packet buffer. It can recognize up to 1024 different MAC
addresses and enables filtering and forwarding at non-blocking 148800 packets/second wire speed.
The function modules integrated in the switch chip include 8 full-duplex compatible media access
controller (MAC) with RMII interface to PHYs, address resolution logic(ARL) for MAC address
searching, self-learning and automatic aging, and buffer management unit (BMU).
The T71L6808A supports IEEE 802.3x full duplex flow control and half duplex back pressure
control. The ability of IEEE 802.3x flow control is auto-negotiated by writing the flow control
ability via MDIO. Speed, duplex, link status and flow control can be acquired by periodically
polling the status of the PHY devices via MDIO.
Port-based VLAN function is also provided by T71L6808A. With the aid of VLAN, broadcast
packet issued within certain VLAN group will not affect the activities in other VLAN group. The
two groups of four ports are suitable for SOHO application at two different working groups.
The T71L6808A also supports trunking applications. With trunking, it is possible to group up to
two full-duplex links together to form a single 400 Mbit/s link.
T71L6808A provides port priority to allow video servers to broadcast or unicast full color
video traffic, that is, all the packets from this priority port will be forwarded to priority queue of
each transmitting port.
The initialization and configuration of the switch is programmed by an external EEPROM.
However, the chip can operate normally with default configuration.
Taiwan Memory Technology, Inc. reserves the right
P. 2
Publication Date:May. 2001
to change products or specifications without notice.
Revision:0.A