Cisco Systems NPE-225 Manual De Usuario

System controller

The system controller provides hardware logic to interconnect the processor, DRAM, and the 
PCI-based system backplane bus. The NSE-1 has 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.

Upgradable memory modules

The NSE-1 uses SDRAM for providing code, data, and packet storage.

Cache memory

The NSE-1 has three levels of cache: primary and secondary cache that are internal to the 
microprocessor with secondary unified cache for data and instruction, and tertiary, 2-MB external 
cache. 

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 NSE-1 does not have packet SRAM.

The NSE-1 performs the following system management functions:

Sending and receiving routing protocol updates

Managing tables, caches, and buffers

Monitoring interface and environmental status

Providing Simple Network Management Protocol (SNMP) management through the console and 
Telnet interface

Accounting for and switching of data traffic 

Booting and reloading images

Managing port adapters (including recognition and initialization during online insertion and 
removal)

Cache—Memory with fast access and small capacity used to temporarily store recently accessed 
data; found either incorporated into the processor or near it. 

DIMM—dual in-line memory module

DRAM—dynamic random-access memory

Instruction and data cache—Instructions to the processor, and data on which the instructions work.

Integrated cache—Cache that is built into the processor; sometimes referred to as internal cache. 
Cache memory physically located outside the processor is not integrated, and is sometimes referred 
to as external cache.

OTP—one time programmable