Intel NETWORK PROCESSOR IXP2800 - Manual (Page 243)

Hardware Reference Manual 243
Intel
®
IXP2800 Network Processor
Media and Switch Fabric Interface
8.1.1 SPI-4
SPI-4 is an interface for packet and cell transfer between a physical layer (PHY) device and a link
layer device (the IXP2800 Network Processor), for aggregate bandwidths of OC-192 ATM and
Packet over SONET/SDH (POS), as well as 10 Gb/s Ethernet applications.
The Optical Internetworking Forum (OIF), www.oiforum.com, controls the SPI-4 Implementation
Agreement document.
SPI-4 has two types of transfers — Data when the RCTL signal is deasserted; Control when the
RCTL signal is asserted. The Control Word format is shown in
Table 83 (this information is from
the SPI-4 specification, shown here for convenience).
Figure 89. Full-Duplex Block Diagram
A9357-02
Intel ® IXP2800
Network Processor
Framing/MAC
Device
(PHY)
UTOPIA-3
or IXBUS
Protocol
Receive and transmit protocol
is SPI-4 and CSIX on transfer-
by-transfer basis.
TDAT RDAT
Bus Converter
Rx
Tx
Tx
Rx
Switch
Fabric
CSIX
Protocol
Notes:
The Bus Converter chip receives and transmits both SPI-4 and CSIX protocols from/to Intel
IXP2800 Network Processor. It steers the data, based on protocol, to either PHY device or
Switch Fabric. PHY interface can be UTOPIA-3, IXBUS, or any other required protocol.