General Description
The RTL8201BL is a single-port Phyceiver with an MII (Media Independent Interface)/SNI(Serial Network Interface). It implements all 10/100M Ethernet Physical-layer functions including the Physical Coding Sublayer (PCS), Physical Medium Attachment (PMA), Twisted Pair Physical Medium Dependent Sublayer (TP-PMD), 10Base-Tx Encoder/Decoder and Twisted Pair Media Access Unit (TPMAU). A PECL interface is supported to connect with an external 100Base-FX fiber optical transceiver. The chip is fabricated with an advanced CMOS process to meet low voltage and low power requirements.
The RTL8201BL can be used as a Network Interface Adapter, MAU, CNR, ACR, Ethernet Hub, Ethernet Switch. Additionally, it can be used in any embedded system with an Ethernet MAC that needs a twisted pair physical connection or fiber PECL interface to external 100Base-FX optical transceiver module.

FEATUREs
The Realtek RTL8201BL is a Fast Ethernet Phyceiver with selectable MII or SNI interface to the MAC chip. It provides the following features:
● Supports MII/7-wire SNI (Serial Network Interface) interface
● Supports 10/100Mbps operation
● Supports half/full duplex operation
● Support of twisted pair or Fiber mode output
● IEEE 802.3/802.3u compliant
● Supports IEEE 802.3u clause 28 auto negotiation
● Supports power down mode
● Supports operation under Link Down Power Saving mode
● Supports Base Line Winder (BLW) compensation
● Supports repeater mode
● Speed/duplex/auto negotiation adjustable
● 3.3V operation with 5V IO signal tolerance
● Low operation power consumption and only need single supply 3.3V
● Adaptive Equalization
● 25MHz crystal/oscillator as clock source
● Multiple network status LED support
● Flow control ability support to co-work with MAC (by MDC/MDIO)
● 48 pin LQFP package