General Description 
The KS8999 contains eight 10/100 physical layer transceivers, nine MAC (Media Access Control) units with an integrated layer 2 switch. The device runs in two modes. The first mode is an eight port integrated switch and the second is as a nine port switch with the ninth port available through an MII (Media Independent Interface).

FEATUREs
• 9 port (8+1) 10/100 integrated switch with eight physical layer transceivers and one MII/SNI interface
• Advanced Ethernet Switch with internal frame buffer
―  128K Byte of SRAM on chip for frame buffering
―  2.0Gbps high performance memory bandwidth
―  Wire speed reception and transmission
―  Integrated address look-up engine, supports 1K absolute MAC addresses
―  Automatic address learning, address aging and address migration
• Advanced Switch Features
―  Supports 802.1p priority and port based priority
―  Supports port based VLAN
―  Supports 1536 byte frame for VLAN tag
―  Supports DiffServ priority, 802.1p based priority or port based priority o broadcast storm protection
• Proven transceiver technology for UTP and fiber operation
―  10BaseT, 100BaseTX and 100BaseFX modes of operation
―  Supports for UTP or fiber on all 8-ports
―  Indicators for link, activity, full/half-duplex and speed
―  Hardware based 10/100, full/half, flow control and auto-negotiation
―  Individual port forced modes (full duplex, 100BaseTX) when auto-negotiation is disabled
―  Full-duplex IEEE 802.3x flow control
―  Half-duplex back pressure flow control
• Supports MDI/MDI-X auto crossover
• External MAC interface (MII or 7-wire) for router applications
• Unmanaged operation via strapping or EEPROM at system reset time (see Reset Reference Circuit section)
• Comprehensive LED support
• Single 2.0V power supply with options for 2.5V and 3.3V I/O
• 900 mA (1.80W) including physical transmit drivers
• Supports both commercial and industry temperature
―  Commercial temperature range: 0°C to +70°C (KS8999)
―  Industrial temperature range: –40°C to +85°C (KS8999I)
• Supports lead free products:
―  Commercial temperature range: 0°C to +70°C (KSZ8999)
―  Industrial temperature range: –40°C to +85°C (KSZ8999I)
• Available in 208-pin PQFP package