General Description
The KS8993 contains three 10/100 physical layer transceivers, three MAC (Media Access Control) units with an integrated layer 2 switch. The device runs in two modes. The first mode is a three port integrated switch and the second is as a three port switch with the third port decoupled from the physical port. In this mode access to the third MAC is provided using a reverse or forward MII (Media Independent Interface) such that an external MAC can be directly connected to the KS8993. This interface also supports the 7-wire (serial network interface) as used by some routing devices.

Features
• 3-port 10/100 integrated switch with physical layer transceivers
• 64k Byte of SRAM on chip for frame buffering
• 1.0Gbps high performance memory bandwidth
• 10BaseT, 100BaseTX and 100BaseFX modes of operation
• Support for UTP or fiber installations
• Superior analog technology for reduced power and die size
• Supports port based VLAN
• QoS feature!! Supports 802.1p based priority or portbased priority
• Indicators for link, activity, full/half-duplex and speed
• Unmanaged operation via strapping at system reset time
• Hardware based 10/100, full/half, flow control and autonegotiation
• Individual port forced modes (full-duplex, 100BaseTX) when auto-negotiation is disabled
• Wire speed reception and transmission
• On chip integrated address look-up engine, supports 1K absolute MAC addresses
• Automatic address learning, address aging and address migration
• Full-duplex IEEE 802.3x flow control (Pause) with force mode option
• Half-duplex back pressure flow control
• Comprehensive LED support
• External MAC interface (MII or SNI 7-wire ) for router applications
• 300mA (0.75W) including physical transmit drivers
• Commercial temperature range: 0°C to +70°C
• Industrial temperature range: –40°C to +85°C
• Available in 128-pin PQFP with single 2.5V power supply