Hello Huck,
Thanks for the response. The datasheet does seem to be unclear regarding the readback operation. I've pinged some designers, and once I get a response I'll be sure to update this post.
In the post above you mention that you were able to successfully write to the DAC. What values of Load1, and Load0 did you use? Were you able to verify the write by measuring the DAC output voltage? I would assume that you used L1=0, L0=1. When this mode is selected both the temporary and DAC registers are updated with the value, and the DAC output updates. It would make sense then that the value of the DAC output voltage is specified in both the temporary and DAC registers when this mode is selected, so when a read is performed I would expect some nonzero value.
I may be able to set up some experiments shortly which should clarify the readback operation. I'll update this post once I find more information on the operation, and make progress on the experiments.
Best Regards,
Matt