
1. Features
RTL8305SB 
2002/04/09 
2
Rev.1.0
 
5-port integrated switch controller with memory and 
transceiver for 10Base-T and 100Base-TX with 
 
5-port 10/100M UTP or 
 
4-port 10/100M UTP + 1-port MII/SNI 
 
Supports PHY mode MII /SNI for router applications 
and MAC mode MII for HomePNA or VDSL solutions  
 
All ports support 100Base-FX with optional flow 
control enable/disable and full/half duplex setting 
 
Non-blocking wire-speed reception and transmission 
and non-head-of-line-blocking forwarding 
 
Fully compliant with IEEE 802.3/802.3u 
auto-negotiation function 
 
Built-in high efficiency SRAM for packet buffer and 
1K entry look-up table, and 16 entry CAM 
 
Supports broadcast storm filtering function 
 
Supports IEEE802.3x full duplex flow control and 
back pressure half duplex flow control 
 
Supports SMI (Serial Management Interface: 
MDC/MDIO) for programming and diagnostics 
 
Supports loop detection function with one LED to 
indicate the existence of loop 
 
Supports loopback function for diagnosis 
 
Flexible 802.1Q Port based VLAN. Up to 5 VLAN 
 
Supports 802.1Q tag VLAN function 
 
Supports ARP VLAN for broadcast packets 
 
Supports Leaky VLAN for unicast packets 
 
Supports QoS function on each port: 
 
QoS based on: (1) Port-based (2) VLAN tag  
(3) TCP/IP header’s TOS/DS 
 
Supports two level priority queues 
 
Weighted round robin service 
 
Supports VLAN priority tag Insert/Remove function 
 
Optional 1536 or 1552 byte maximum packet length 
 
Supports reserved control frames (DID= 
0180C2000003~0180C200000F) filtering function 
 
Flexible LED indicators for link, activity, speed, 
full/half duplex and collision 
 
LEDs blink upon reset for LED diagnostics 
 
Supports two Power Reduction methods:  
 
Power saving mode by cable detection 
 
Power down mode (by PHY register 0.11) 
 
Robust baseline wander correction for improved 
100BASE-TX performance
 
Optional Crossover Detection and Auto Correction 
function 
 
Physical layer port Polarity Detection and Correction 
function 
 
Optional
EEPROM interface for configuration 
 
25MHz crystal or OSC input. Single 3.3V power 
system like by translating of an external transistor
 
0.25 μm, CMOS technology, 3.3V/2.5V with 3.3V 
input tolerant, 128 pin PQFP package