AD7745/6

I'm trying to understand the register map.

The data sheet for the AD7745/46 only shows registers 0x00-0x12.

The Register Summary in the eval software shows 9 more and documents them 0x13-0x1B, and then extends all the way to 0x30 undocumented with 6 missing.   

The eval software writes 0x00-0x30 with all present, and some of the undocumented registers are not 0x00.

Is there any documentation on the actual register map ?