I configured a circuit according to (figure 98. SPI Control Mode Connection Diagram with Internal Reference in AD7779 datasheet)
Sampled ADC value is stable and normal on default setting of REF_MUX_CTRL[7:6]=.
Do I have to configure REF_MUX_CTRL[7:6] bitfield to  to operate internal reference?
or Is it okay to configure both options  or  with the connection of internal reference?
added a question
[edited by: hellokyehyun at 7:22 AM (GMT 0) on 22 Feb 2019]