Cisco 4000 User Manual

Page 9

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Overview of the Cisco 4000 Series Routers 1-9

Memory Systems

Table 1-3

Cisco 4000 Series Processor and Memory Specifications

Memory Systems

The Cisco 4000 series memory systems (see Figure 1-2) have the following functions:

Main memory—Stores the running configuration and routing tables. The Cisco IOS
software executes from main memory.

Shared memory—Used for packet buffering by the router’s network interfaces.

Flash memory—Stores the operating system software image. In the Cisco 4500-M and
4700-M, the Flash memory also stores the boot helper software.

NVRAM—Stores the system configuration file and the virtual configuration register.

Boot EPROM—In the Cisco 4000-M, erasable programmable read-only memory
(EPROM)-based memory stores the boot helper—a subset of the Cisco IOS
software—and the ROM monitor. In the Cisco 4500-M and Cisco 4700-M, only the
ROM monitor is EPROM based. The boot helper image allows you to boot the router

Description

Cisco 4000-M Cisco 4500-M Cisco 4700-M

Processor

40-MHz Motorola
68EC030

100-MHz IDT Orion
RISC

1

1. The Orion microprocessor is based on the MIPS R4400 and is pin-compatible.

133-MHz IDT Orion
RISC

Main memory
(DRAM)

2

2. DRAM = dynamic random-access memory.

4, 8, 16, or 32 MB

8, 16, or 32 MB

16, 32, or 64 MB

Secondary cache
memory

None

None

512 KB

Shared memory
(DRAM)

4 or 16 MB

4, 8, or 16 MB

4, 8, or 16 MB

Flash memory

4 or 8 MB

4, 8, 16, 32, or 64 MB

4, 8, 16, 32, or 64 MB

NVRAM

3

3. NVRAM = nonvolatile random-access memory.

128 KB

128 KB

128 KB

Boot ROM

128 KB–8 MB

128–512 KB

128–512 KB

Boot Flash

Not available

4–16 MB

4–16 MB

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