Initialization And Self-Test Problems - Cisco uBR924 Installation Manual

Initialization and Self-Test Problems

Figure 4-1
Initialization and Self-Test Problems
When the Cisco uBR924 router first powers on, the following occurs:
1.
2.
Cisco uBR924 Router Hardware Installation Guide
4-2
Cisco uBR924 Cable Access Router Front Panel LEDs
OK
CATV
The router runs its self-test and diagnostic procedures. All LEDs (except for the four Ethernet LEDs
and the ACT LED) briefly light and then turn off when self-test and diagnostic procedures are
successful. The procedures ensure Cisco uBR924 components are functioning. To complete all
self-test and diagnostic procedures, the Cisco uBR924 processor must be able to:
Perform a system reset trap.
–
Fetch and execute instructions from the ROM Monitor area of the bootflash chip.
–
– Write several internal registers and reset the control program without crashing.
– Correctly configure the port A and port D registers.
– Perform conditional branches.
– Ensure all software-controlled LEDs are functional.
The next step of the self-test is to initialize the memory controller and its Dynamic Random Access
Memory (DRAM). If a failure exists, the OK LED turns off and the following LEDs on the bottom
row turn on to indicate the specific problem that occurred.
The router first attempts to initialize the memory controller. If this fails, the DS and DSNR
–
LEDs light and remain on to indicate a problem with the memory controller. Otherwise, the
console port is initialized and the banner is output to the console port.
Next, the router performs a self-test on the low registers of the DRAM. If a problem exists, the
–
V2, the DS, and the DSNR LEDs light and remain on to indicate a processor cache failure.
If the cache memory passed the self-test, the next portion of DRAM is tested. If this self-test
–
fails, the V-OK, V2, DS, and DSNR LEDs light and remain on to indicate a memory or
controller problem.
– The router then attempts to clear the BSS area of the DRAM; if this fails, the V2, DS, and US
LEDs light and remain on to indicate a memory or controller problem.
– Finally, the router attempts to clear the rest of DRAM. If this fails, the DS LED lights and
remains on, while all other LEDs remain off to indicate a possible memory or controller
problem.
ACT 1 2 3 4
LINK V OK V1 V2 DS
Chapter 4
MSG
US DSNR
Cisco uBR900
SERIES
Troubleshooting
OL-0338-01 (3/2000)