Cisco 1600 - Manual (Page 5)

Universal Asynchronous Receiver−Transmitter (UART)UART is an SCC integrated on the
M68360. It provides the necessary user interface. It has one RS232 port, and a data communications
equipment (DCE) (console) RJ45.
Note: UART has no Auxiliary (data terminal equipment − DTE) port. Higher console speeds (up to
115.2 Kbps) are supported. The download of Cisco IOS software images over the console port is
supported through xmodem or ymodem.
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WAN interface cards (WIC)WICs are media−specific network interfaces responsible for data
transfer in and out of the 160x series router. WICs communicate with the CPU through the CPU Bus
for packet transfer. Specialized Controllers (or application−specific integrated circuits − ASICs) used
for media support perform the above−mentioned functionality. WICs do not support Online Insertion
and Removal (OIR).
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Power supplyPower supply provides power to various components of the router.
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Memory Details
Different kinds of memory reside in the Cisco 1600 Series Router, and each of them is handled in a different
way and for different purposes.
Figure 7 Memory Details
DRAM
DRAM is logically divided into Main Processor memory and Shared Input/Output (I/O) memory.
Main Processor MemoryIt is used to store routing tables, fast switching cache, running
configuration, and so on. It can take unused shared I/O memory, if needed.
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Shared I/O MemoryIt is used for temporary storage of packets in system buffers at the time of
process switching, and interface buffers during fast switching. Cisco 1600 Series Routers running
Cisco IOS software versions prior to the integration of CSCdk40685 (
registered customers only ) have a
fixed I/O memory of 512 KB. After CSCdk40685, if the router has enough memory, it allocates 25%
to I/O memory. If not, I/O memory remains at 512 KB.
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You can use the show memory summary command to see the distribution of DRAM memory.
Router−1600#show memory summary
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 20B3A7C 13419908 2334632 11085276 10907924 10907920
I/O 2D80000 4718592 247324 4471268 4466128 4464852
....
! −−− Output Suppressed
Physically, DRAM is a combination of 2 MB on−board non−parity chips, and one Single In−line Memory
Module (SIMM) [72−pin, 60 ns, with or without parity]. If SIMM is non−parity, total DRAM can be up to 18
Cisco − Cisco 1600 Series Router Architecture