upload ios to cisco 3640

[nicholaswc]

I upload the ios to my cisco 3640 by xmodem and got below information. Is this ios not suitable for this router?
rommon 1 > xmodem -c c3640-is-mz.123-13a.bin
Do not start the sending program yet...
File size Checksum File name
11902284 bytes (0xb59d4c) 0x7e7a c3640-telco-mz.123-26.bin

WARNING: All existing data in flash will be lost!
Invoke this application only for disaster recovery.
Do you wish to continue? y/n [n]: y
Ready to receive file c3640-is-mz.123-13a.bin ...
Erasing flash at 0x317c0000
program flash location 0x31080000
amd_flash_cmd: timeout on AMD flash command

program_flash: location 0x31080000 wrote 0x74115b47,contains 0xe7115b47
program flash failure at location 0x31080000 - aborting
rommon 2 >