The Becker site under what's new has the radio manual, but I do not think the DSP unit is included in the radio manual, but is in the owners manual.
http://www.beckerautosound.com/
I have a 1997 with a CDR-210 and DSP was not an option that year. I do have a 2001 owners manual, and it says just to push the DSP button to turn it on. Jeff