I found an error in Cortex-M3 assembler.
I found that the assembler in CCS 4.2 is case0sensitive in an instruction it. That is,
it ne ; error. assembler can not recognize the condition ne
addne r0, r0, #4
----------------------------------
it NE ; no error
addne r0, r0, #4
-----------------------------------
The assembler seems not to recoginize the lower-case condition in "it" instruction.