The Free On-line Dictionary of Computing (30 December 2018):

Data Address Generator

    (DAG) The mechanism which generates temporary
   memory addresses for data that is transferred between memory
   and registers in a Digital Signal Processor.

   Certain DSP architectures incorporate more than one DAG to
   simplify the programming needed to move blocks of data between
   buffers.

   For instance, certain Fast Fourier Transform algorithms
   requiring bit reversing, can use the DAG for that purpose,
   or they can use two DAGS, one for Program Memory Data (PMD),
   and the other for Data Memory Data (DMD).

   (1997-08-12)