About between nRF52840 and nRF9160

[Andy kang]

Hi, I'm designing water meter modem using the nRF52840 + nRF9160.
I will apply nRF52840 as a HOST CPU and the nRF160 contol by nRF52840. (please refer to attached picture.)
Which Interface do I have to connect  between nRF52840 and nRF9160?

[Heidi]

Hi, you have opened up to identical tickets so I'm closing this one. Please refer to the other ticket for answers.