IXP1200 Network Processor Family ATM OC-3/12/Ethernet IP Router Example Design
Application Note 7
Modified on: 3/20/02,
1.0 Introduction
Intel develops example software to demonstrate the capabilities of the IXP1200 Network Processor
Family. This document describes the implementation of example software demonstrating the
IXP1200, IXP1240, and IXP1250 in an ATM environment. In particular, this example design uses
the IXP12xx to route IP packets between ATM and Ethernet networks.
From the point of view of this example software, the IXP1240 and IXP1250 are synonymous - the
project utilizes their common hardware CRC feature; but is not aware of the IXP1250’s additional
ECC capability. The IXP1200, on the other hand, does not have hardware CRC support, and thus
supports only a software-CRC configuration.
This document serves as a companion to the comments in the source code, and is intended to
clarify the structure and general workings of the design. The following material is covered: purp ose
and scope of the design; software partitioning and data flow, StrongARM® Core and microengine
initialization; microengine functional block description; subsystems and data structures; inter-
thread signaling; project configuration; testing environments; simulation support; limitations, and
example design extension. The end of this document contains lists of document conventions,
acronyms and definitions, and related documents.

1.1 Purpose of ATM Example Design

This example design demonstrates just one software architecture in which the IXP12xx can be used
in ATM-related designs. It is not intended to be ’production ready ’. Rather, it is intended to serve as
a starting point for customers designing similar applications. It is also intended for customers to
understand the IXP12xx Network Processor’s capabilities and expected performance.
Users may modify the code, adding additional modules that are proprietary or more specific to their
needs, and estimate performance, although performance numbers gained from this design are
applicable only to the example as presented. Customer changes to the design can result in either
increases or decreases in performance.

1.2 Scope of Example Design

This document describes the implementation in sufficient detail that a programmer should be able
to successfully modify the source code. The README.txt file that accompanies the software
should be consulted for instructions on running the project, building the code, and the actual layout
of the source files.