Cisco 7200 VXR User Manual page 12

Field-Replaceable Units
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System controller
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• Upgradable memory modules
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Packet SRAM for storing packets of information in preparation for fast switching
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The NPE-150 has 1 MB of SRAM and the NPE-200 has 4 MB of SRAM. No other network
processing engine or network services engine has SRAM.
Cache memory
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Cisco 7200 VXR Installation and Configuration Guide
1-12
The NPE-100 and NPE-150 have an R4700 microprocessor that operates at an internal clock
speed of 150 MHz.
The NPE-G1 BCM 1250 maintains and executes the system management functions for the
Cisco 7200 VXR routers and also holds the system memory and environmental monitoring
functions.
The NSE-1 has one system controller that provides processor access to the midplane and single
I/O controller PCI buses. The system controller also allows port adapters on either of the two
midplane PCI buses to access SDRAM.
The NPE-400 has one system controller that provides system access.
The NPE-300 has two system controllers that provide 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 to access SDRAM.
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 the
port adapters on either of the two midplane PCI buses to access SDRAM.
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-G1 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.
The NSE-1 uses SDRAM for providing code, data, and packet storage.
The NPE-400 uses SDRAM for storing all packets received or sent from network interfaces. The
SDRAM memory array in the system allows concurrent access by port adapters and the
processor.
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.
The NPE-175 and NPE-225 use SDRAM for providing code, data, and packet storage.
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-G1 has two levels of cache: a primary and a secondary cache that are internal to the
microprocessor, with the secondary unified cache for data and instruction.
The NSE-1 has three levels of cache: a primary and a secondary unified cache that are internal
to the microprocessor, and a tertiary 2-MB external cache.
Chapter 1 Cisco 7200 VXR Product Overview
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