how to store a value on one of the interface registers of 1701

Hi guys,

I am using a 1701 in standalone mode, with the use of an external EEPROM.

I need to store some values in the interface registers of the 1701 so they can be written back to the EEPROM.

After reading this guide: https://ez.analog.com/message/48651#48651 and trying out different things, I still haven't managed to accomplish what I need.

What I need is to save a value of 28.0 format that is sent as a control signal to a voltage controlled multiplexer in SigmaStudio. I need to store this value to the EEPROM, so my getaway there seem to be the interface registers of the 1701.

I am very confused however, it seems that I cannot route directly the signal that goes to the multiplexer to an interface register. I am reading in the manual that the interface registers are somehow related to GPIOs. Does this mean that I cannot store any desired value from my design to an interface register?

All the examples that use interface registers are using GPIOs as well. Let's say that I have a DC block in my design and I want to store its value to an interface register, is that possible? And if yes, how? What would the role of a GPIO be in this case?

thank you for your time