Sigma Studio, booting DSP in assembly.
So, these things are a pain to program...  Having spent months with two of them I'd strongly suggest you get yourself their programmer EVAL-ADUSB2EBZ "USBi" it's about $80USD.   With that you can program directly from SigmaStudio, program the external eeprom, and make changes in real time.   So for instance you can adjust the cutoff frequency of a filter, or change the gain in the software and you can hear the results right away.   

I see your part has selfboot?   Hope you put down an eeprom for it to boot from, if so that's probably your easiest bet.  If you don't buy a programmer you can export a hex file for the eeprom from SigmaStudio, and then program your eeprom with an eeprom programmer or your FPGA.   Here's a link to Analog's forums showing how to export.

Now if you don't have an eeprom...  You can try to program all the registers directly, but that was a task and a half.  Again you can output a series of C files from SigmaStudio that show how to write all the registers, and program memory of the device you are working with.  Here's a presentation on that.  This took a lot of work for me to get it right.

Finally if you make a simple project in SigmaStudio, then try to "program" it, then you can look in the output console.   There you'll see all the writes they do to program the devices.  Be warned though when they show a single address writing multiple bytes that does not mean you can just write 1 byte, increment address, write another byte.  They expect if you're using I2C to write the address then all the data bytes for that address.

Again I'd buy the programmer, it's really useful even after you figure out how to program it yourself.