From reading the DSP datasheet (CXD2500BQ) and other documents I have roughly figured out the way a CD is read. First the laser is focused onto the CD and then the table of contents is read. Using the table of contents, the CD reader can then seek to the track on the disc using the absolute timecode. A seeking operation starts by repeatedly jumping tracks while keeping an eye on the timecode. A track in this context is not an audio track, but the tracks between the center and the outer rim of the disc of which there are 22188 on a standard 12 cm CD. When the laser is close enough to the desired timecode, the track adjustment is made to focus it onto the desired track. If it landed a little bit before the desired track the output is muted until the disc rotates to the desired area and the correct data is read. I have not yet figured out exactly how to operate the DSP but I am now closer to figuring it out.

As for the CDROM decoder (CXD1196AR), I plan on connecting it to a SNES when I can obtain one. It should be as easy as connecting the 8 data pins, read write strobes, address select pin and interrupt pin directly to the expansion port pins. The polarity of the interrupt pin on the decoder is selectable according to the signal on another pin so if need be I can set it accordingly. Then I can burn the BIOS file onto a cartridge and run the self check. If my wiring is sound, the SNES doesn't check anything else and my decoder chip isn't dead then the CDROM Decoder test should pass.