Cisco 7206 - VXR Router Installation Manual page 26

Field-Replaceable Units
Reduced instruction set computing (RISC) microprocessor
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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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• Cache memory
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• Two environmental sensors for monitoring the cooling air as it leaves the chassis
• Boot ROM for storing sufficient code for booting the Cisco IOS software; the NPE-175, NPE-200,
and NPE-225 have a boot ROM
Cisco 7206 Installation and Configuration Guide
1-8
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-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 to access SDRAM.
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-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-100, NPE-150, and NPE-200 have unified cache SRAM that functions as the
secondary cache for the microprocessor. (The primary cache is within the microprocessor.)
The NPE-175 and NPE-225 have two levels of cache: a primary that is internal to the processor
and a secondary, 2-MB external cache that provides additional high-speed storage for data and
instructions.
Chapter 1 Product Overview
OL-5102-02