Chapter1 Product Overview
Route Processor
1-28
Cisco XR 12416 Router Installation Guide
OL-13833-01
PRP SDRAM
The PRP uses Error Checking and Correction (ECC) Synchronized Dynamic
Random Access Memory (SDRAM) to store routing tables, protocols, network
accounting applications, and to run Cisco IOS software.
Tabl e 1-2 lists the DRAM configurations for the PRP. If you are using:
•One DIMM—Bank 1 (U15) must be populated first.
•Two DIMMs—You cannot mix memory sizes; both banks must contain the
same size DIMM.
Caution DRAM DIMMs must be 3.3-volt, 60-nanosecond devices only. Do not attempt to
install other devices in the DIMM sockets. To prevent memory problems, use the
Cisco approved memory products listed in Table 1 -2.
PRP SRAM
Static Random Access Memory (SRAM) provides 2 MB of secondary CPU cache
memory. Its principal function is to act as a staging area for routing table updates,
and for information sent to and received from the line cards. SRAM is not
user-configurable and cannot be upgraded in the field.
Table1-2 PRP DRAM Configurations
Total
SDRAM SDRAM Sockets Number of DIMMs
512 MB1
1. Default shipping configuration.
U15 (bank 1)
U18 (bank 2)
One 512 MB DIMM
or
Two 2 56 MB DIM Ms
1 GB U15 (bank 1)
U18 (bank 2)
One 1 GB DIMM
or
Two 5 12 MB DIM Ms
2 GB U15 (bank 1)
U18 (bank 2)
Two 1GB DIMMs