PGA112: PGA112 can be connected to GND?

Hi ZH, 

Thanks for posting on e2e, sorry for the delay in response due to the US Holiday. 
I recommend connecting all digital lines to DVDD via a weak pull-up resistor (4.7k-10k), as shown in this layout example: 

As you can see the CS is pulsed low for the duration of the transaction and then pulled high to finish the interaction: 

All the best,
Carolina