[quote user="fan Linlin"]"Bit fields are packed in memory from most significant byte to least significant byte ."[/quote]
That sentence is the specification for the order of the fields. In big endian mode, the first field starts at the most significant bit in the bit-field, as shown in the figure. The ARM EABI bit-field layout is dictated by AEABI document produced by ARM. For further details, see http://infocenter.arm.com -> ARM Software development tools -> Application Binary Interface ... -> ABI for the ARM 32-bit Architecture -> Procedure Call Standard -> Section 7.1.7 "Bit-fields"
Please show us the definition of your bit-field struct.
What ARM compiler version are you using in CCS 2? (It is not the same as the CCS version).
Which --abi option are you using?