The IP1826D is a non-blocking, store-and-forward architecture switch controller, which supports 24-port SS-SMII, 2-port RGMII/ SERDES, and one-port MII for a 24+2G smart switch application. With two built-in SERDES transceiver, the IP1826D provides a very cost-effective solution for a 24+2 Gigabit fiber without external Gigabit Ethernet transceivers.
 

Note: In the following paragraphs, 24-port SS-SMII is referred to as port 0 ~ port 23, 2-port RGMII as port 24 (or Giga 1) and port 25 (or Giga 2) and MII port as port 26. These ports are named as P0 ~ P26 in abbreviation. The PHY address for P0 ~ P23 is “8~31” respectively. The PHY addresses “1” and “2” correspond to P24 and P25 respectively.
 

The IP1826D embeds a 2.75Mb SSRAM for the use of packet buffer and 4K MAC address table. It provides a 2-wire CPU interface, which allows the designer to access to the register. The system configuration can be downloaded from EEPROM upon reset. The serial LED information is provided through a 2-wire LED interface, simplifying the PCB layout task for LED display. With the external logic devices, the IP1826D can show the status of link, speed, duplex, and activity.
 

In addition to the fundamental function such as the flow control, the broadcast storm control and the programmable MAC address aging time, the IP1826D also supports many advanced features that allow the designer to implement the smart switch features. The IGMP (Internet Group Management Protocol) snooping provides a method to build a multicast link without complicated CPU code. The designer can also use the 2 levels of priority queue to support the real-time streaming application. Supporting both port-based and tag-based VLAN, the IP1826D can partition the network traffic by programming the VLAN table. Furthermore, the IP1826D supports both non-VID related tag-based VLAN and VID related tag-based VLAN. The access control based on the MAC layer, the IP layer, and TCP/UDP layer provides a method for the designer to implement the Class of Service and the network security.