Specifications

4 Network Processing Engine Replacement Instructions
Network Processing Engine Description
The network processing engines consist of the following components:
• Reduced instruction set computing (RISC) microprocessor
— The NPE-100 and NPE-150 have an R4700 microprocessor that operates at an internal clock
speed of 150 MHz.
— The NPE-175 has an RM5270 microprocessor that operates at an internal clock speed of
200 MHz.
— The NPE-200 has an R5000 microprocessor that operates at an internal clock speed of
200 MHz.
— The NPE-225 has an RM5271 microprocessor that operates at an internal clock speed of
262 MHz.
— The NPE-300 uses an RM7000 microprocessor that operates at an internal clock speed of
262 MHz.
• System controller
— The NPE-100, NPE-150, and NPE-200 have a system controller that uses direct memory
access (DMA) to transfer data between DRAM and packet SRAM on the network processing
engine.
— The NPE-175 and NPE-225 have one system controller that provides processor access to the
two midplane and single I/O controller PCI buses. The system controller also allows port
adapters on either of the two midplane PCI buses access to SDRAM.
— The NPE-300 has two system controllers that provide processor access to the two midplane
and single I/O controller PCI buses. The system controllers also allow port adapters on either
of the two midplane PCI buses access to SDRAM.
• Upgradable memory modules
— The NPE-100, NPE-150, and NPE-200 use DRAM for storing routing tables, network
accounting applications, packets of information in preparation for process switching, and
packet buffering for SRAM overflow (except in the NPE-100, which contains no packet
SRAM). The standard configuration is 32 MB, with up to 128 MB available through single
in-line memory module (SIMM) upgrades.
— The NPE-175 and NPE-225 use SDRAM for providing code, data, and packet storage.
— The NPE-300 uses SDRAM for storing all packets received or sent from network interfaces.
The SDRAM also stores routing tables and network accounting applications. Two
independent SDRAM memory arrays in the system allow concurrent access by port adapters
and the processor.
• Packet SRAM for storing packets of information in preparation for fast switching
— The NPE-100 does not have packet SRAM.
— The NPE-150 has 1 MB of SRAM.
— The NPE-175 does not have packet SRAM.
— The NPE-200 has 4 MB of SRAM.
— The NPE-225 does not have packet SRAM.
— The NPE-300 does not have packet SRAM.