TMS320F28035: Register requires read/write using 32-bit access and 16-bit word access rather than bit-level accessed?

Part Number: TMS320F28035

Dear champs,

We notice that eCAN control register requires read/write using 32-bit access.

However, our customer concerns and wonders what register can be accessed using bit-accessed or word-accessed in codes?

That is, when can we write codes in this way:

ECanaRegs.CANME.bit.ME0 = 1;

(We found this is not correct in CCS watch window "Expressions")

When should we write it in this way:

EcanaRegs.CANME.all = 0x0007003F;

We are confused.

Is there any document about this?

Is this only a special case in eCAN registers?

We would like to know how this applies to all registers (not limited to eCAN).

Wayne