Hardware Reference Manual 241
Intel® IXP2800 Network Processor
Media and Switch Fabric Interface
Media and Switch Fabric Interface 8

8.1 Overview

The Media and Switch Fabric (MSF) Interface connects the IXP2800 Network Processor to a
physical layer device (PHY) and/or to a Switch Fabric. The MSF consists of separate receive and
transmit interfaces, each of which can be separately configured for either SPI-4 Phase 2 (System
Packet Interface), for PHY devices or for the CSIX-L1 protocol, for Switch Fabric Interfaces.
The receive and transmit ports are unidirectional and independent of each other. Each port has 16
data signals, a clock, a control signal, and a parity signal, all of which use LVDS (differential)
signaling, and are sampled on both edges of the clock. There is also a flow control port consisting
of a clock, data, and ready status bits, for communicating between two IXP2800 Network
Processors, or a IXP2800 Network Processor and a Switch Fabric Interface; these are also LVDS,
dual-edge data transfer.
Signal usage and the receive and transmit functions, are illustrated in Figure88, and described in
the sections that follow.
Note: Detailed information about CSRs is contained in the Intel® IXP2400 and IXP2800 Network
Processor Programmer’s Reference Manual.