General Description
The RTL8208 is a highly integrated 8 port, 10Base-T/100Base-TX/FX, Ethernet transceiver implemented in 0.25µm CMOS technology. It is currently the world’s smallest Octal-PHY chip package with many special patented features. Traditional SD pins in 100Base-FX are omitted by Realtek patent to obtain fewer pin-count. Flexible hardware settings are provided to configure the various operating modes of the chip. The RTL8208 consists of 8 separate and independent channels. Each channel consists of an RMII/SMII/SS-SMII interface to MAC controller, and hardware pins are used to configure the interface for RMII, or SMII, or SS-SMII mode. In RMII mode, another hardware pin is used to set port-pair loop mode (PP-LPBK mode), which can extend physical transmission length or perform physical media transport operations without any switch controller.

FEATUREs
  Supports 8-port integrated physical layer and transceiver for 10Base-T and 100Base-TX
  Up to 8 ports support of 100Base-FX
  Reduced 100Base-FX interface (patented)
  Robust baseline wander correction for improved 100BASE-TX performance
  Fully compliant with IEEE 802.3/802.3u
  IEEE 802.3u compliant Auto-negotiation for 10/100 Mbps control
  Hardware controlled Flow control advertisement ability
  Supports RMII/SMII/SS-SMII interfaces
  Multiple driving capabilities of RMII/SMII/SS-SMII
  Supports 25MHz crystal as clock source for RMII with 50MHz REFCLK output for MAC
  Very low power consumption
  Supports port-pair loop mode (PP-LPBK mode)
  Supports two Power reduction methods:
      1. Power saving mode (cable detection)
      2. Power down mode
  Power-on auto reset function eliminates the need for external reset circuits
  Flexible LED display modes through 2-wire serial LED control interface
  128-pin PQFP
  2.5V/3.3V power supply
  0.25µm, CMOS technology