How to read or write %MW internal word in DFB?

The GET_4X, EF allows to read %MW internal word in a DFB.
The PUT_4X EF allows to write%MW internal word in a DFB.

See Unity Pro on line Help for more details on these EFs .

Note : These EFs belong to Obsolete Library.
The goal of a DFB is to be re-usabled in any application, %MWs must be used with care inside DFBs to avoid overlaps which will be not seen during analyse, as only a pointer is given to the instruction.