Intel IXP1200

Intel has become a leader in marketing network processors as part of their Internet Exchange Architecture. Currently, most network processor companies are extremely secretive about their products. Intel is the exception. Of the four network processors described in this article, Intel's IXP1200 is the only one for which you can directly download a datasheet from the Web.

The IXP1200, shown in Figure 5, consists of a StrongARM processor, six RISC micro-engines, and interfaces to SRAM/SDRAM memory, PCI bus, and Intel's proprietary IX Bus. The IXP1200 has been designed to do fast path and slow path processing in one chip. The StrongARM portion of the processor can be programmed for the slow path with conventional C/C++ tools. The six micro-engines are designed for fast path processing. Each micro-engine has four hardware contexts and can context switch in a single instruction. The micro-engines are limited to 4KB of program space, which is actually quite a bit, since they are programmed in microcode.

Intel provides assembly tools for the microcode as well as a simulator for debugging the non-StrongARM parts of the IXP1200. Intel ships the IXP1200 development environment with example code for Layer 2 and Layer 3 bridging and routing.