Cisco 3600 Series Configuration Note page 7

Figure 3
Screw
Step 7
When you are ready to replace the cover, refer to the section "Replacing the Cover" later in this
document.
If you are replacing DRAM SIMMs, continue with the next section, "Upgrading DRAM." If you are
upgrading your Flash memory, continue with the section "Upgrading Flash Memory" later in this
document.
Upgrading DRAM
This section describes how to upgrade DRAM on the system card. You might need to upgrade
DRAM for the following reasons:
•
You have upgraded to a new Cisco Internetwork Operating System (Cisco IOS) feature set or
release.
•
You are using very large routing tables or many protocols (for example, when the router is set up
as part of both a large external network and your internal network).
Cisco 3620 DRAM
The Cisco 3620 router contains four 72-pin single SIMM sockets (or banks) for DRAM, numbered
0 through 3. (See Figure 4.) Each socket can be filled with a single 32-bit-wide, 72-pin DRAM
SIMM. You can use the memory-size iomem software command to configure DRAM as a mixture
of shared memory, which is used for data transmitted or received by network modules and WAN
interface cards, and primary or main memory, which is reserved for the CPU. For further information
about this command, refer to the Cisco IOS configuration guides and command references.
Note
Removing the Cisco 3640 Cover
S Y
S T
E M
R P
S
C O
N
A U
X
Lift the cover free and set it aside.
DRAM in the Cisco 3620 supports only single-bank SIMMs and 32-bit operation.
A C
0
T IV
1
E
R E 2
A D 3
Y
1
P C
M C
0
I A
Cisco 3600 Series Memory Upgrade Configuration Note
Upgrading DRAM
7