Cisco 7120 Series User Manual page 35

Chapter 1 Overview
Figure 1-33 Network Processor Card
Back
Environmental
The network processor card consists of the following components:
• Reduced Instruction Set Computing (RISC) microprocessor
• Two system controllers—Provide processor access to two separate banks of SDRAM and that permit
devices on both PCI buses to access either SDRAM bank. This means that devices on different PCI
buses can access different SDRAM banks simultaneously.
• Upgradable memory modules—SDRAM system memory is up to 256 MB. (SDRAM packet
memory is fixed at 64 MB.) SDRAM memory stores packets received or sent from network
interfaces, routing tables, and network accounting applications. There are two independent SDRAM
memory arrays that allow concurrent access by interfaces and the processor.
The network processor card contains two SDRAM slots for user-configurable system and packet
Note
memory, DIMM 1 and DIMM 2. The amount of memory installed in slot DIMM 1 must be greater than
or equal to the amount of memory installed in slot DIMM 2, and slot DIMM 2 can be zero.
Slot DIMM 0 is used exclusively for packet memory and is fixed at 64 MB in the factory.
Cache memory
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NVRAM
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Cisco 7120 series routers have two levels of cache: a primary cache that is internal to the
microprocessor and a secondary, 2-MB (fixed) external cache that provides additional
high-speed storage for data and instructions.
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Polarization
notch alignment
Boot ROM
Cisco 7100 Series VPN Router Installation and Configuration Guide
Functional Overview
Front
Polarization
notch alignment
SDRAM
DIMM 1
SDRAM
DIMM 2
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sensor
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SDRAM
DIMM 0
Flash memory
SIMM
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