The AMCC PowerPC 440GX processor offers the versatility and bandwidth required for today's demanding networking and storage applications. This highly integrated device delivers CPU performance of up to 667MHz and executes up to two instructions per cycle. A PCI-X interface that supports frequencies of up to 133MHz and an on-chip double data rate (DDR) SDRAM controller, supporting up to DDR333, further enhance processor capabilities. With embedded state-of-the-art peripheral cores, the 440GX processor is ideal for networking control plane applications, RAID controllers, iSCSI processing, and storage area networking (SAN) equipment.I/O processing applications can benefit from the integrated messaging unit, designed to the I2O specification. This messaging unit improves system performance by enabling the 440GX processor to communicate via I2O messages with a host system on the PCI bus. This allows the processor to work as an intelligent I/O adapter controller.The 256KB on-chip SRAM can be configured either as a performance- enhancing L2 cache, or as memory mapped SRAM for low-latency access. Used as L2, the 256KB SRAM is a 4-way set-associative, unified data/instruction cache, which can benefit many applications. As memory-mapped SRAM, it has lower memory access latency than the SDRAM, offering quick access to crucial code or data. Software-controlled and with parity support, this memory is ideal for storing data packets, critical code segments, Ethernet or DMA descriptors, or other application-specific data. When configured as a memory-mapped region, this SRAM is accessible from any PLB master, which can further improve application performance.