What is needed to boot a SigmaDSP processor?

Any of the SigmaDSPs can be booted from a system's host microcontroller.

The ADAU1701, ADAU1702, ADAU1401, ADAU1442, ADAU1445, and ADAU1446 also have a selfboot feature that allows them to boot from an EEPROM without a microcontroller being present in the system.