thank you so much for the help...
now I recoverd the U boot, but still problem with Environment area. It shows,
NVRAM: Original Critical is BAD
NVRAM: Mirror Critical is BAD
NVRAM: Original and Mirror don't match
NVRAM: Using Mirror
also, when I try to set and save into file it shows,
CCW9M2443 # setenv ipaddr 192.168.37.17
CCW9M2443 # saveenv
Saving Environment to Digi NVRAM...
*** Error: NVE_NOT_FOUND: (U-Boot)
why UBoot is not able to accss the environment variables...???