Sorry very new to Analgo Device's DSP's. Are there any examples of Blackfin processors being interfaced to parallel peripherals such as AD7651? All the EVAL boards have a ton of glue logic in the form of a FPGA. I assume this is not needed in a custom approach but can't find any examples.
For the AD7651 I suggest using the SPI serial interface which should be pretty straightforward.
Try starting with one of the example projects.