RTL8305S

2002/02/19

Rev. 1.2

2

1. Features

5-port integrated switch with physical layer and

transceiver for 10Base-T and 100Base-TX with

5-port 10/100M UTP or

4-port 10/100M UTP + 1-port MII/SNI

PHY mode MII/SNI interface for router application

MAC mode MII interface for HomeLAN/100Base-FX

application

1Mbit internal RAM for packet buffer

Internal 1K look-up table entries

25MHz crystal or OSC input

Non-blocking wire-speed reception and transmission

Fully compliant with IEEE 802.3/802.3u

Supports broadcast storm filtering function

Support full duplex 802.3x flow control and half

duplex back-pressure flow control

LED indicators for link/activity, speed, full/half duplex

and collision

LEDs blinking upon reset for LED diagnostics

Unmanaged operation by strapping upon reset

Power saving with cable detection

Low power consumption at 3.3V operating voltage

128-pin PQFP package

2. General Description

The RTL8305S is a highly integrated layer 2 single chip switch controller which incorporates 5 MACs (Media Access

Controller), 5 physical layer transceivers, 1-Mbit SRAM and 1K-entry look-up table into one single chip.

The RTL8305S contains 5 ports, and each one provides support for a 10Base-T (10Mbps) or 100Base-TX (100Mbps) network

connection. The fifth port (port 4) can be configured as a MII/SNI to work with a routing engine, HomePHY or a fiber

transceiver for a 100Base-FX application. And each operation mode can be easily set up by hardware strapping upon restart or

power-on.

The RTL8305S is designed for a stand-alone switch system through hardware strapping upon reset to achieve unmanaged

operation and can be easily integrated with xDSL/Cable modem router. With the least peripheral components and using a

25MHz crystal, the RTL8305S has the best system cost structure. The integrated RTL8305S chip benefits from low power

consumption and ease of use for SOHO 5-port switch or xDSL/Cable router applications.