AX88655 AB

Features:

• 5-port Gigabit Ethernet switch integrating MACs,packet buffer memory and switching engine with RGMII/GMII/MII interface
• RGMII support REV 1.3 with 3.3V IO
• Full Duplex 1000 Mbit/s.
• Full and Half Duplex 10/100 Mbit/s
• Supports auto-sensing or manual selection for speed and duplex capability with an embedded MPU
• Store-and-forward operation support
• Performs full wire-speed switching with Head of Line (HOL) blocking prevention
• Supports up to 8 Port-based VLAN Groups
• Supports broadcast storm filtering.
• Quality-of-Service provisioning on 802.1P tag and port-pairs with two priority queues
• By-port Egress/Ingress bandwidth (rate) control
• Embedded 128K Byte SRAM for packet buffer
• Supports packet length up to 1522 bytes
• Supports 9K/12K byte JUBMO packet
• Integrated two-way Address-Lookup engine and table for 4K MAC addresses
• Programmable aging mechanism for the two-way 4K MAC addresses table
• Two hashing schemes: direct and XOR mode.
• Support ingress port security mode, incoming packets with unknown source MAC address could be dropped
• Egress/Ingress Port Mirroring for Sniffer function.
• Flow control
   - Full-duplex IEEE 802.3x flow control
   - Half-duplex back pressure flow control
   - Optional smart flow control for mix-speed connection
• Supports port-based trunking for high-bandwidth links
• Provides 5 GPIO ports
• Provides EEPROM interface for auto-configuration
• System clock input is one 25MHz Crystal and one 125MHz from PHY GCLK output
• 1.8 and 3.3V operations
• 3.3 I/Os and packaged in 272-pin BGA


Application

5-port Gigabit Layer 2 Switches for workgroup
High-port count Layer 2 switches with trunking
High performance solution of Ethernet backbone


Specifications

Description	SYM	Min	Max	Units
Operating Temperature	Ta	0	+70	°C
Storage Temperature	Ts	-55	+150	°C
Supply Voltage	Vcc	-0.3	+4.0	V
Input Voltage	Vin	-0.3	Vdd+0.5	V
Output Voltage	Vout	-0.3	Vdd+0.5	V
Lead Temperature (soldering 10 seconds maximum)	Tl	-55	+220	°C

Description

 The AX88655AB Gigabit switch controller supports eight 10/100/1000 Mbps ports in wire-speed operation. The AX88655AB Gigabit switch controller provides eight 10/100/1000 Ethernet ports with RGMII/GMII/MII interface. For each ports, the AX88655AB supports GMII/RGMII (802.3ab, 1000BASE-T) interface with full-duplex operation at Gigabit speed, full- or half-duplex operation at 10/100 Mbps speed (using 802.3/u, 10/100BASE-T) and polls the status of PHYs with an embedded MPU.

The device supports 4K internal MAC addresses which are shared by all ports with an embedded SRAM. The learning/routing engine is implemented with a two-way hash/linear algorithm to reduce possibility of routing collision.

Basically the AX88655AB supports non-blocking wire speed forwarding rate and no Head-of-Line (HOL) blocking issue. The AX88655AB provides two flow-control mechanisms to avoid loss of data: an optional jamming based backpressure flow control in the half-duplex operation and IEEE 802.3x in the full-duplex mode.

To support Quality of Service (QoS), each output port has two priority queues and their assignment can be based on the 802.1p priority field or Port-Pair setting. Each output port retrieves the frames from the shared buffer based on queuing and sends them to the transmitting (Tx) FIFO.