Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help spm2fieldtrip”.

  SPM2FIELDTRIP converts an SPM8 meeg object into a FieldTrip raw data structure
 
  Use as
    data = spm2fieldtrip(D)
  where D is the SPM meeg object which you can load in with SPM_EEG_LOAD
  and where data is a FieldTrip raw data structure as if it were returned
  by FT_PREPROCESSING.
 
  See also FT_PREPROCESSING, SPM_EEG_LOAD